instruction,input,output,context
Earth science is the study of,(A) solid Earth (B) Earths oceans (C) Earths atmosphere (D) all of the above,D,"Geology is the study of the Earths solid material and structures and the processes that create them. Some ideas geologists might consider include how rocks and landforms are created or the composition of rocks, minerals, or various landforms. Geologists consider how natural processes create and destroy materials on Earth, and how humans can use Earth materials as resources, among other topics. Geologists study rocks in the field to learn what they can from them. "
A geologist would be most likely to investigate how,(A) mountains form (B) people cause pollution (C) tornadoes occur (D) two of the above,A,"Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). "
Which type of Earth scientist might look for petroleum for an oil company?,(A) meteorologist (B) climatologist (C) geologist (D) ecologist,C,"Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). "
Chemical oceanography is the study of the,(A) human pollution of ocean water (B) naturally occurring elements in ocean water (C) rising levels of ocean water (D) rocks on the ocean floor,B,"Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. "
The problem of global warming is most likely to be the focus of a scientist known as a,(A) planetary geologist (B) seismologist (C) physical oceanographer (D) climatologist,D,"With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. "
Which type of Earth scientist would you expect to give a weather report?,(A) volcanologist (B) meteorologist (C) climatologist (D) environmental scientist,B,"Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Using modern technology such as radars and satellites, meteorologists are getting more accurate at forecasting the weather all the time. Climatology is the study of the whole atmosphere, taking a long-range view. Climatologists can help us better understand how and why climate changes (Figure 1.2). Carbon dioxide released into the atmo- sphere is causing the global climate to change. "
Tools typically used by meteorologists include,(A) satellites (B) radar (C) telescopes (D) two of the above,D,Predicting the weather requires a lot of weather data. Technology is used to gather the data and computers are used to analyze the data. Using this information gives meteorologists the best chance of predicting the weather. 
study of Earths weather,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,G,"Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Using modern technology such as radars and satellites, meteorologists are getting more accurate at forecasting the weather all the time. Climatology is the study of the whole atmosphere, taking a long-range view. Climatologists can help us better understand how and why climate changes (Figure 1.2). Carbon dioxide released into the atmo- sphere is causing the global climate to change. "
study of earthquakes,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,F,Geologists study earthquake waves to see Earths interior. Waves of energy radiate out from an earthquakes focus. These are called seismic waves (Figure 6.1). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earths interior. 
study of Earths oceans,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,B,"Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. "
study of solid Earth,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,C,"Geology is the study of the Earths solid material and structures and the processes that create them. Some ideas geologists might consider include how rocks and landforms are created or the composition of rocks, minerals, or various landforms. Geologists consider how natural processes create and destroy materials on Earth, and how humans can use Earth materials as resources, among other topics. Geologists study rocks in the field to learn what they can from them. "
study of human effects on Earth,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,D,"Environmental scientists study the effects people have on their environment, including the landscape, atmosphere, water, and living things. Climate change is part of climatology or environmental science. "
study of all aspects of planet Earth,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,E,"Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. "
study of the universe,(A) astronomy (B) oceanography (C) geology (D) environmental science (E) Earth science (F) seismology (G) meteorology,A,"The study of the universe is called cosmology. Cosmologists study the structure and changes in the present universe. The universe contains all of the star systems, galaxies, gas, and dust, plus all the matter and energy that exists now, that existed in the past, and that will exist in the future. The universe includes all of space and time. "
Earth science is a branch of geology.,(A) true (B) false,B,"Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). "
Some geologists specialize in the study of soil.,(A) true (B) false,A,"Geology is the study of the solid Earth. Geologists study how rocks and minerals form. The way mountains rise up is part of geology. The way mountains erode away is another part. Geologists also study fossils and Earths history. There are many other branches of geology. There is so much to know about our home planet that most geologists become specialists in one area. For example, a mineralogist studies minerals, as seen in (Figure 1.11). Some volcanologists brave molten lava to study volcanoes. Seismologists monitor earthquakes worldwide to help protect people and property from harm (Figure 1.11). Paleontologists are interested in fossils and how ancient organisms lived. Scientists who compare the geology of other planets to Earth are planetary geologists. Some geologists study the Moon. Others look for petroleum. Still others specialize in studying soil. Some geologists can tell how old rocks are and determine how different rock layers formed. There is probably an expert in almost anything you can think of related to Earth! Geologists might study rivers and lakes, the underground water found between soil and rock particles, or even water that is frozen in glaciers. Earth scientists also need geographers who explore the features of Earths surface and work with cartographers, who make maps. Studying the layers of rock beneath the surface helps us to understand the history of planet Earth (Figure 1.12). "
Rock layers below Earths surface are a record of Earths history.,(A) true (B) false,A,"To be able to discuss Earth history, scientists needed some way to refer to the time periods in which events happened and organisms lived. With the information they collected from fossil evidence and using Stenos principles, they created a listing of rock layers from oldest to youngest. Then they divided Earths history into blocks of time with each block separated by important events, such as the disappearance of a species of fossil from the rock record. Since many of the scientists who first assigned names to times in Earths history were from Europe, they named the blocks of time from towns or other local places where the rock layers that represented that time were found. From these blocks of time the scientists created the geologic time scale (Figure 1.1). In the geologic time scale the youngest ages are on the top and the oldest on the bottom. Why do you think that the more recent time periods are divided more finely? Do you think the divisions in the scale below are proportional to the amount of time each time period represented in Earth history? In what eon, era, period and epoch do we now live? We live in the Holocene (sometimes called Recent) epoch, Quaternary period, Cenozoic era, and Phanerozoic eon. "
The science of oceanography started with mapping the oceans.,(A) true (B) false,A,"Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. "
Scientists have not yet visited the deepest parts of the ocean.,(A) true (B) false,B,"Only a specially designed vehicle can venture beneath the sea surface. But only very special vehicles can reach the ocean floor. Three are described here and pictured in Figure 14.21: In 1960, scientists used the submersible Trieste to travel into the Mariana Trench. They succeeded, but the trip was very risky. Making humans safe at such depths costs a lot of money. People have not traveled to this depth again. In 2012, the film director, James Cameron, dove to the bottom of the Mariana Trench by himself in a submersible that he had built for the purpose. The vehicle named Alvin was developed soon after Trieste. The submersible has made over 4,000 dives deep into the ocean. People can stay underwater for up to 9 hours. Alvin has been essential for developing a scientific understanding the worlds oceans. Today, remote-control vehicles, called remotely operated vehicles (ROVs) go to the deepest ocean floor. They dont have any people on board. However, they carry devices that record many measurements. They also collect sediments and take photos. "
Most of Earths water is in rivers and lakes.,(A) true (B) false,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
Humans have had relatively little impact on the oceans.,(A) true (B) false,B,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
There are several branches of oceanography.,(A) true (B) false,A,"Oceanography is the study of the oceans. The word oceanology might be more accurate, since ology is the study of. Graph is to write and refers to map making. But mapping the oceans is how oceanography started. More than 70% of Earths surface is covered with water. Almost all of that water is in the oceans. Scientists have visited the deepest parts of the ocean in submarines. Remote vehicles go where humans cant. Yet much of the ocean remains unexplored. Some people call the ocean the last frontier. Humans have had a big impact on the oceans. Populations of fish and other marine species have been overfished. Contaminants are polluting the waters. Global warming is melting the thick ice caps and warming the water. Warmer water expands and, along with water from the melting ice caps, causes sea levels to rise. There are many branches of oceanography. Physical oceanography is the study of water movement, like waves and ocean currents (Figure 1.13). Marine geology looks at rocks and structures in the ocean basins. Chemical oceanography studies the natural elements in ocean water. Marine biology looks at marine life. "
Meteorologists study meteors.,(A) true (B) false,B,"Meteorologists dont study meteors they study the atmosphere! The word meteor refers to things in the air. Meteorology includes the study of weather patterns, clouds, hurricanes, and tornadoes. Meteorology is very important. Using radars and satellites, meteorologists work to predict, or forecast, the weather (Figure 1.14). The atmosphere is a thin layer of gas that surrounds Earth. Climatologists study the atmosphere. These scientists work to understand the climate as it is now. They also study how climate will change in response to global warming. The atmosphere contains small amounts of carbon dioxide. Climatologists have found that humans are putting a lot of extra carbon dioxide into the atmosphere. This is mostly from burning fossil fuels. The extra carbon dioxide traps heat from the Sun. Trapped heat causes the atmosphere to heat up. We call this global warming (Figure 1.15). "
The burning of fossil fuels contributes to global warming.,(A) true (B) false,A,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
Flowing water can cause erosion by dissolving minerals in rocks.,(A) true (B) false,A,"Flowing water is a very important agent of erosion. Flowing water can erode rocks and soil. Water dissolves minerals from rocks and carries the ions. This process happens really slowly. But over millions of years, flowing water dissolves massive amounts of rock. Moving water also picks up and carries particles of soil and rock. The ability to erode is affected by the velocity, or speed, of the water. The size of the eroded particles depends on the velocity of the water. Eventually, the water deposits the materials. As water slows, larger particles are deposited. As the water slows even more, smaller particles are deposited. The graph in Figure 10.1 shows how water velocity and particle size influence erosion and deposition. "
More slowly flowing water can carry larger sediments.,(A) true (B) false,B,"When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. "
The size of sediments determines how they are carried by flowing water.,(A) true (B) false,A,"The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. "
Clay and silt are carried in flowing water by suspension.,(A) true (B) false,A,"The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. "
Runoff is only a minor cause of soil erosion.,(A) true (B) false,B,"Runoff carved channels in the soil in Figure 19.1. Running water causes most soil erosion, but wind can carry soil away too. What humans do to soil makes it more or less likely to be eroded by wind or water. Human actions that can increase soil erosion are described below. "
Rapidly flowing mountain streams cause little deposition.,(A) true (B) false,A,"Streams often start in mountains, where the land is very steep. You can see an example in Figure 10.4. A mountain stream flows very quickly because of the steep slope. This causes a lot of erosion and very little deposition. The rapidly falling water digs down into the stream bed and makes it deeper. It carves a narrow, V-shaped channel. "
Slowly flowing rivers erode their channels more at the bottom than at the sides.,(A) true (B) false,B,"Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. "
Floodplains are poor places for growing crops.,(A) true (B) false,B,"Within the floodplain of the Nile, soils are fertile enough for productive agriculture. Beyond this, infertile desert soils prevent viable farming. Not all the consequences of flooding are negative. Rivers deposit new nutrient-rich sediments when they flood, so floodplains have traditionally been good for farming. Flooding as a source of nutrients was important to Egyptians along the Nile River until the Aswan Dam was built in the 1960s. Although the dam protects crops and settlements from the annual floods, farmers must now use fertilizers to feed their cops. Floods are also responsible for moving large amounts of sediments about within streams. These sediments provide habitats for animals, and the periodic movement of sediment is crucial to the lives of several types of organisms. Plants and fish along the Colorado River, for example, depend on seasonal flooding to rearrange sand bars. "
A levee forms from the largest sediments a river carries.,(A) true (B) false,A,"A flood occurs when a river overflows it banks. This might happen because of heavy rains. Floodplains As the water spreads out over the land, it slows down and drops its sediment. If a river floods often, the floodplain develops a thick layer of rich soil because of all the deposits. Thats why floodplains are usually good places for growing plants. For example, the Nile River in Egypt provides both water and thick sediments for raising crops in the middle of a sandy desert. Natural Levees A flooding river often forms natural levees along its banks. A levee is a raised strip of sediments deposited close to the waters edge. You can see how levees form in Figure 10.8. Levees occur because floodwaters deposit their biggest sediments first when they overflow the rivers banks. "
Sinkholes are caused by groundwater erosion.,(A) true (B) false,A,"As erosion by groundwater continues, the ceiling of a cave may collapse. The rock and soil above it sink into the ground. This forms a sinkhole on the surface. You can see an example of a sinkhole in Figure 10.10. Some sinkholes are big enough to swallow vehicles and buildings. "
broad flat area on both sides of a river where it floods its banks,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,D,"Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. "
underground hole or cavern eroded by groundwater,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,E,"Working slowly over many years, groundwater travels along small cracks. The water dissolves and carries away the solid rock, gradually enlarging the cracks. Eventually, a cave may form (Figure 1.2). "
deposit that forms when a mountain stream flows suddenly onto flatter land,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,A,"When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. "
raised strip of sediments deposited along the bank of a river,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,C,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
hole on the surface of the ground that forms when a cave collapses,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,F,"If the roof of a cave collapses, a sinkhole could form. Some sinkholes are large enough to swallow up a home or several homes in a neighborhood (Figure 1.3). Water flows through Russell Cave Na- tional Monument in Alabama. "
triangular deposit that forms when a river empties into a body of still water,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,B,"When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. "
body of water that forms when a meander is cut off from the rest of the river,(A) alluvial fan (B) delta (C) levee (D) floodplain (E) cave (F) sinkhole (G) oxbow lake,G,"Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. "
Agents of erosion include,(A) gravity (B) waves (C) ice (D) all of the above,D,"The agents of soil erosion are the same as the agents of all types of erosion: water, wind, ice, or gravity. Running water is the leading cause of soil erosion, because water is abundant and has a lot of power. Wind is also a leading cause of soil erosion because wind can pick up soil and blow it far away. Activities that remove vegetation, disturb the ground, or allow the ground to dry are activities that increase erosion. What are some human activities that increase the likelihood that soil will be eroded? "
Erosion is always followed by,(A) deposition (B) weathering (C) suspension (D) saltation,A,"Erosion by gravity is called mass wasting. Mass wasting can be slow and virtually imperceptible, or rapid, massive, and deadly. Weathered material may fall away from a cliff because there is nothing to keep it in place. Rocks that fall to the base of a cliff make a talus slope. Sometimes as one rock falls, it hits another rock, which hits another rock, and begins a landslide. "
Factors that determine how much erosion runoff can cause include,(A) how fast the water is moving (B) how much water is flowing (C) whether the land is bare or covered with plants (D) all of the above,D,"When a lot of rain falls in a short period of time, much of the water is unable to soak into the ground. Instead, it runs over the land. Gravity causes the water to flow from higher to lower ground. As the runoff flows, it may pick up loose material on the surface, such as bits of soil and sand. Runoff is likely to cause more erosion if the land is bare. Plants help hold the soil in place. The runoff water in Figure 10.3 is brown because it eroded soil from a bare, sloping field. Can you find evidence of erosion by runoff where you live? What should you look for? Much of the material eroded by runoff is carried into bodies of water, such as streams, rivers, ponds, lakes, or oceans. Runoff is an important cause of erosion. Thats because it occurs over so much of Earths surface. "
A waterfall forms when a stream flows,(A) from lower to higher elevations (B) from harder to softer rocks (C) from one meander to another (D) from side to side in its floodplain,B,"Mountain streams may erode waterfalls. As shown in Figure 10.5, a waterfall forms where a stream flows from an area of harder to softer rock. The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step, creating a waterfall. As erosion continues, the waterfall gradually moves upstream. "
"When flowing water slows down, which of the following sediments does it drop first?",(A) gravel (B) sand (C) silt (D) clay,A,"Flowing water slows down when it reaches flatter land or flows into a body of still water. What do you think happens then? The water starts dropping the particles it was carrying. As the water slows, it drops the largest particles first. The smallest particles settle out last. "
Which statement about stalactites is false?,(A) They form on the floors of caves (B) They consist of mineral deposits (C) They look like icicles (D) They grow slowly,A,"Groundwater carries dissolved minerals in solution. The minerals may then be deposited, for example, as stalag- mites or stalactites (Figure 1.4). Stalactites form as calcium carbonate drips from the ceiling of a cave, forming beautiful icicle-like formations. The word stalactite has a c, and it forms from the ceiling. Stalagmites form as calcium carbonate drips from the ceiling to the floor of a cave and then grow upwards. The g in stalagmite means it forms on the ground. If a stalactite and stalagmite join together, they form a column. One of the wonders of visiting a cave is to witness the beauty of these amazing and strangely captivating structures. Some of the largest, and most beautiful, natural crystals can be found in the Naica mine, in Mexico. These gypsum crystals were formed over thousands of years as groundwater, rich in calcium and sulfur flowed through an underground cave. Check it out: A relatively small sinkhole in a Georgia parking lot. Stalactites hang from the ceiling and stalagmites rise from the floor of Carlsbad Caverns in New Mexico. The large stalagmite on the right is almost tall enough to reach the ceiling (or a stalactite) and form a column. Click image to the left or use the URL below. URL: "
What forms when a river erodes the outside of a curve and deposits sediments on the inside of the curve?,(A) delta (B) floodplain (C) meander (D) sinkhole,C,"Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. "
landform that results when a sandbar builds up enough to rise above the waters surface,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,B,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
artificial barrier parallel to a shore that reduces beach erosion,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,G,"Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. "
landform that results when waves create a hole in a wave-cut cliff,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,F,Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. 
artificial barrier perpendicular to the shore that reduces erosion by longshore drift,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,C,"Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. "
landform that results when waves erode the top of a sea arch,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,D,Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. 
underwater ridge of sand running parallel to shore that is deposited by waves,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,E,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
ridge of sand extending out from shore that is caused by longshore drift,(A) spit (B) barrier island (C) groin (D) sea stack (E) sandbar (F) sea arch (G) breakwater,A,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
Factors that determine the size of ocean waves include,(A) speed of the wind (B) length of time the wind blows (C) distance the wind blows (D) all of the above,D,"Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. "
Sediments you are most likely to find on a beach include,(A) clay (B) silt (C) pieces of shell (D) all of the above,C,"In relatively quiet areas along a shore, waves may deposit sand. Sand forms a beach, like the one in Figure 10.13. Many beaches include bits of rock and shell. You can see a close-up photo of beach deposits in Figure 10.14. "
Erosion by ocean waves can cause,(A) sandbars (B) spits (C) cliffs (D) beaches,C,"Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. "
Landforms created by longshore drift include,(A) spits (B) sea arches (C) sea stacks (D) two of the above,A,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
A breakwater is most similar to a,(A) spit (B) barrier island (C) wave-cut cliff (D) pillar of rock,B,"Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. "
Landforms caused by ocean wave deposition include,(A) groins (B) sea stacks (C) sea caves (D) sandbars,D,Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. 
Which series of landforms shows the correct order in which a stretch of rocky shoreline may be eroded?,(A) sea arch (B) cliff (C) sea stack (D) b cliff (E) sea arch (F) sea stack (G) c sea stack (H) cliff (I) sea arch (J) d cliff (K) sea stack (L) sea arch,B,Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. 
Bigger waves can carry more sediment.,(A) true (B) false,A,"Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. "
The smallest sediments in ocean water are deposited on the shore.,(A) true (B) false,B,"Eventually, the sediment in ocean water is deposited. Deposition occurs where waves and other ocean motions slow. The smallest particles, such as silt and clay, are deposited away from shore. This is where water is calmer. Larger particles are deposited on the beach. This is where waves and other motions are strongest. "
Most waves strike the shore at an angle rather than straight on.,(A) true (B) false,A,Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. 
Longshore drift carries sediments far inland.,(A) true (B) false,B,Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. 
Groins are built to prevent the formation of sandbars.,(A) true (B) false,B,"Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. "
Sediment in ocean water scrapes rocks like sandpaper.,(A) true (B) false,A,"Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. "
Longshore drift moves sand opposite to the direction of prevailing winds.,(A) true (B) false,B,Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. 
The end of a spit may hook around toward the open ocean.,(A) true (B) false,B,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
A barrier island is generally small and round in shape.,(A) true (B) false,B,"Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. "
Sand collects on both sides of a groin.,(A) true (B) false,B,"Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. "
Glaciers presently cover about 40 percent of Earths surface.,(A) true (B) false,B,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
Continental glaciers are long and narrow.,(A) true (B) false,B,"Glaciers form when more snow falls than melts each year. Over many years, layer upon layer of snow compacts and turns to ice. There are two different types of glaciers: continental glaciers and valley glaciers. Each type forms some unique features through erosion and deposition. An example of each type is pictured in Figure 10.27. A continental glacier is spread out over a huge area. It may cover most of a continent. Today, continental glaciers cover most of Greenland and Antarctica. In the past, they were much more extensive. A valley glacier is long and narrow. Valley glaciers form in mountains and flow downhill through mountain river valleys. "
Valley glaciers flow downhill through river valleys.,(A) true (B) false,A,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
Continental glaciers form cirques and horns.,(A) true (B) false,B,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
A glacier picks up sediments when they freeze to ice at the bottom of the glacier.,(A) true (B) false,A,"Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. "
The narrow end of a drumlin points in the direction that the glacier moved.,(A) true (B) false,A,"Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. "
All glaciers move because of gravity.,(A) true (B) false,A,"Whether an ice field moves or not depends on the amount of ice in the field, the steepness of the slope and the roughness of the ground surface. Ice moves where the pressure is so great that it undergoes plastic flow. Ice also slides at the bottom, often lubricated by water that has melted and travels between the ground and the ice. The speed of a glacier ranges from extremely fast, where conditions are favorable, to nearly zero. Because the ice is moving, glaciers have crevasses, where cracks form in the ice as a result of movement. The large crevasse at the top of an alpine glacier where ice that is moving is separated from ice that is stuck to the mountain above is called a bergshrund. Crevasses in a glacier are the result of movement. "
The main way glaciers cause erosion is by ice wedging.,(A) true (B) false,B,"Like flowing water, flowing ice erodes the land and deposits the material elsewhere. Glaciers cause erosion in two main ways: plucking and abrasion. Plucking is the process by which rocks and other sediments are picked up by a glacier. They freeze to the bottom of the glacier and are carried away by the flowing ice. Abrasion is the process in which a glacier scrapes underlying rock. The sediments and rocks frozen in the ice at the bottom and sides of a glacier act like sandpaper. They wear away rock. They may also leave scratches and grooves that show the direction the glacier moved. "
Glaciers are getting smaller because of global warming.,(A) true (B) false,A,"Glaciers are melting back in many locations around the world. When a glacier no longer moves, it is called an ice sheet. This usually happens when it is less than 0.1 km2 in area and 50 m thick. "
The valley carved by a mountain glacier has gently sloping walls.,(A) true (B) false,B,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
rounded hollow carved in the side of a mountain by a glacier,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,D,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
type of glacier that is spread out over a large area,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,A,"The types of glaciers are: Continental glaciers are large ice sheets that cover relatively flat ground. These glaciers flow outward from where the greatest amounts of snow and ice accumulate. Alpine (valley) glaciers flow downhill from where the snow and ice accumulates through mountains along existing valleys. Ice caps are large glaciers that cover a larger area than just a valley, possibly an entire mountain range or region. Glaciers come off of ice caps into valleys. The Greenland ice cap covers the entire landmass. "
long low hill of sediments deposited by a glacier,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,G,"Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. "
type of glacier that forms in mountains,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,E,"Glaciers form when more snow falls than melts each year. Over many years, layer upon layer of snow compacts and turns to ice. There are two different types of glaciers: continental glaciers and valley glaciers. Each type forms some unique features through erosion and deposition. An example of each type is pictured in Figure 10.27. A continental glacier is spread out over a huge area. It may cover most of a continent. Today, continental glaciers cover most of Greenland and Antarctica. In the past, they were much more extensive. A valley glacier is long and narrow. Valley glaciers form in mountains and flow downhill through mountain river valleys. "
winding ridge of sand deposited by a stream of meltwater,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,C,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
jagged ridge that remains when two cirques form on opposite sides of a mountain,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,B,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
sharp peak that is left behind when glaciers erode all sides of a mountain,(A) continental glacier (B) arte (C) esker (D) cirque (E) valley glacier (F) horn (G) drumlin,F,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
"Today, continental glaciers cover most of",(A) Alaska (B) Canada (C) Greenland (D) all of the above,C,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
Features caused by valley glacier erosion include,(A) eskers (B) cirques (C) drumlins (D) end moraines,B,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
A trimline shows the,(A) highest level a valley glacier reached (B) direction in which a glacier traveled (C) greatest distance a glacier advanced (D) ending edge of a continental glacier,A,Transmission lines on big towerslike those in the opening photo abovecarry high-voltage electric current from power plants to electric substations. Smaller towers and individual power poles carry lower-voltage current from electric substations to homes and businesses. 
A headwall is the,(A) starting point of a continental glacier (B) highest ridge of an esker (C) highest cliff of a cirque (D) low spot in an arte,C,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
A valley glacier changes a V-shaped river valley to a,(A) kettle lake (B) drumlin field (C) U-shaped valley (D) meltwater stream,C,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
A thick layer of sediments left behind by a retreating continental glacier is called,(A) ground moraine (B) end moraine (C) glacial till (D) none of the above,A,"Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. "
The last time glaciers dipped as far south as Chicago and New York City was,(A) 10 million years ago (B) 1 million years ago (C) 120 (D) 000 years ago (E) d 12 (F) 000 years ago,D,"During the Quaternary Period, the climate cooled. This caused a series of ice ages. Glaciers advanced southward from the North Pole. They reached as far south as Chicago and New York City. Sea levels fell because so much water was frozen in glaciers. This exposed land bridges between continents. The land bridges allowed land animals to move to new areas. Some mammals adapted to the cold by evolving very large size and thick fur. An example is the woolly mammoth, shown in Figure 7.25. Other mammals moved closer to the equator. Those that couldnt adapt or move went extinct, along with many plants. The last ice age ended about 12,000 years ago. By then, our own species, Homo sapiens, had evolved. After that, we were eyewitnesses to the story of life. As a result, the recent past is less of a mystery than the billions of years before it. "
Examples of imprint fossils made by compression are,(A) drawings on rock made by prehistoric humans (B) frozen remains of elephant-like mammoths (C) footprints and animal tracks (D) fossil leaves,D,"Some fossils form when their remains are compressed by high pressure, leaving behind a dark imprint. Compression is most common for fossils of leaves and ferns, but can occur with other organisms. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Fossilized insects have been found preserved in amber which is hardened,(A) flower nectar (B) tree sap (C) wood (D) None of the above,B,"The soft parts of organisms almost always decompose quickly after death. Thats why most fossils consist of hard parts such as bones. Its rare even for hard parts to remain intact long enough to become fossils. Fossils form when water seeps through the remains and deposits minerals in them. The remains literally turn to stone. Remains are more likely to form fossils if they are covered quickly by sediments. Once in a while, remains are preserved almost unchanged. For example, they may be frozen in glaciers. Or they may be trapped in tree resin that hardens to form amber. Thats what happened to the wasp in Figure 7.8. The wasp lived about 20 million years ago, but even its fragile wings have been preserved by the amber. "
Fossilized stomach contents may indicate,(A) the diet of the animal (B) the vegetation type in its habitat (C) whether an animal walked (D) swam or flew (E) d a b,D,"By knowing something about the type of organism the fossil was, geologists can determine whether the region was terrestrial (on land) or marine (underwater) or even if the water was shallow or deep. The rock may give clues to whether the rate of sedimentation was slow or rapid. The amount of wear and fragmentation of a fossil allows scientists to learn about what happened to the region after the organism died; for example, whether it was exposed to wave action. "
An animal is more likely to a fossil if it:,(A) is buried deeply in the ground (B) is left on the surface of the ground (C) does not contain bones or other hard body parts (D) all of the above are about equally likely to result in fossilization,A,"Despite these problems, there is a rich fossil record. How does an organism become fossilized? A rare insect fossil. "
Marine fossils on the top of Mt. Everest indicate,(A) sea level was once higher than the top of Mt (B) the fossils are not actually marine fossils (C) but just look like them (D) c the rock at the top of Mt (E) d someone put them up there as a trick,C,"Fossils give clues about major geological events. Fossils can also give clues about past climates. Fossils of ocean animals are found at the top of Mt. Everest. Mt. Everest is the highest mountain on Earth. These fossils show that the area was once at the bottom of a sea. The seabed was later uplifted to form the Himalaya mountain range. An example is shown in the Figure 11.4. Fossils of plants are found in Antarctica. Currently, Antarctica is almost completely covered with ice. The fossil plants show that Antarctica once had a much warmer climate. "
Preserved traces can include burrows.,(A) true (B) false,A,"Fossils are preserved remains or traces of organisms that lived in the past. Most preserved remains are hard parts, such as teeth, bones, or shells. Examples of these kinds of fossils are pictured in Figure 11.1. Preserved traces can include footprints, burrows, or even wastes. Examples of trace fossils are also shown in Figure 11.1. "
Scientists have discovered fossil footprints.,(A) true (B) false,A,"Fossils are the preserved remains or traces of organisms that lived during earlier ages. Remains that become fossils are generally the hard parts of organismsmainly bones, teeth, or shells. Traces include any evidence of life, such as footprints like the dinosaur footprint in Figure 7.7. Fossils are like a window into the past. They provide direct evidence of what life was like long ago. A scientist who studies fossils to learn about the evolution of living things is called a paleontologist. "
Complete preservation occurs only when remains are preserved in rock.,(A) true (B) false,B,The process by which remains or traces of living things become fossils is called fossilization. Most fossils are preserved in sedimentary rocks. 
"In the past, fossils inspired legends of monsters.",(A) true (B) false,A,"It wasnt always known that fossils were parts of living organisms. In 1666, a young doctor named Nicholas Steno dissected the head of an enormous great white shark that had been caught by fisherman near Florence, Italy. Steno was struck by the resemblance of the sharks teeth to fossils found in inland mountains and hills (Figure ??). Most people at the time did not believe that fossils were once part of living creatures. Authors in that day thought that the fossils of marine animals found in tall mountains, miles from any ocean could be explained in one of two ways: The shells were washed up during the Biblical flood. (This explanation could not account for the fact that fossils were not only found on mountains, but also within mountains, in rocks that had been quarried from deep below Earths surface.) The fossils formed within the rocks as a result of mysterious forces. But for Steno, the close resemblance between fossils and modern organisms was impossible to ignore. Instead of invoking supernatural forces, Steno concluded that fossils were once parts of living creatures. "
It is very likely that any given organism will become a fossil.,(A) true (B) false,B,"Its very unlikely that any given organism will become a fossil. The remains of many organisms are consumed. Remains also may be broken down by other living things or by the elements. Hard parts, such as bones, are much more likely to become fossils. But even they rarely last long enough to become fossils. Organisms without hard parts are the least likely to be fossilized. Fossils of soft organisms, from bacteria to jellyfish, are very rare. "
Fossils in older rocks are more similar to animals that live today than fossils in younger rocks.,(A) true (B) false,B,"That life on Earth has changed over time is well illustrated by the fossil record. Fossils in relatively young rocks resemble animals and plants that are living today. In general, fossils in older rocks are less similar to modern organisms. We would know very little about the organisms that came before us if there were no fossils. Modern technology has allowed scientists to reconstruct images and learn about the biology of extinct animals like dinosaurs! "
Fossils of ocean animals have been found at the top of Mt. Everest.,(A) true (B) false,A,"Fossils give clues about major geological events. Fossils can also give clues about past climates. Fossils of ocean animals are found at the top of Mt. Everest. Mt. Everest is the highest mountain on Earth. These fossils show that the area was once at the bottom of a sea. The seabed was later uplifted to form the Himalaya mountain range. An example is shown in the Figure 11.4. Fossils of plants are found in Antarctica. Currently, Antarctica is almost completely covered with ice. The fossil plants show that Antarctica once had a much warmer climate. "
Fossils form when remains are replaced by minerals.,(A) true (B) false,A,Most fossils form when a dead organism is buried in sediment. Layers of sediment slowly build up. The sediment is buried and turns into sedimentary rock. The remains inside the rock also turn to rock. The remains are replaced by minerals. The remains literally turn to stone. Fossilization is illustrated in Figure 11.2. 
Fossils show that Antarctica once had a much warmer climate.,(A) true (B) false,A,"By knowing something about the climate a type of organism lives in now, geologists can use fossils to decipher the climate at the time the fossil was deposited. For example, coal beds form in tropical environments but ancient coal beds are found in Antarctica. Geologists know that at that time the climate on the Antarctic continent was much warmer. Recall from Concept Plate Tectonics that Wegener used the presence of coal beds in Antarctica as one of the lines of evidence for continental drift. "
Index fossils are the first fossils ever discovered of an extinct species.,(A) true (B) false,B,Index fossils are commonly used to match rock layers in different places. You can see how this works in Figure 
Complete preservation is valuable because scientists can study the organisms DNA.,(A) true (B) false,A,"Most uncommon is the preservation of soft-tissue original material. Insects have been preserved perfectly in amber, which is ancient tree sap. Mammoths and a Neanderthal hunter were frozen in glaciers, allowing scientists the rare opportunity to examine their skin, hair, and organs. Scientists collect DNA from these remains and compare the DNA sequences to those of modern counterparts. "
There are no plants in Antarctica so there are no plant fossils there.,(A) true (B) false,B,"Fossils give clues about major geological events. Fossils can also give clues about past climates. Fossils of ocean animals are found at the top of Mt. Everest. Mt. Everest is the highest mountain on Earth. These fossils show that the area was once at the bottom of a sea. The seabed was later uplifted to form the Himalaya mountain range. An example is shown in the Figure 11.4. Fossils of plants are found in Antarctica. Currently, Antarctica is almost completely covered with ice. The fossil plants show that Antarctica once had a much warmer climate. "
Teeth are more likely than feathers to be preserved as fossils.,(A) true (B) false,A,"Usually its only the hard parts that are fossilized. The fossil record consists almost entirely of the shells, bones, or other hard parts of animals. Mammal teeth are much more resistant than other bones, so a large portion of the mammal fossil record consists of teeth. The shells of marine creatures are common also. "
People first started discovering fossils about 150 years ago.,(A) true (B) false,B,"Of all the organisms that ever lived, only a tiny number became fossils. Still, scientists learn a lot from fossils. Fossils are our best clues about the history of life on Earth. "
All fossils form when remains of dead organisms are covered with sediments.,(A) true (B) false,B,Most fossils form when a dead organism is buried in sediment. Layers of sediment slowly build up. The sediment is buried and turns into sedimentary rock. The remains inside the rock also turn to rock. The remains are replaced by minerals. The remains literally turn to stone. Fossilization is illustrated in Figure 11.2. 
dark stain in rock left by the remains of an organism,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,G,"Fossils may form in other ways. With complete preservation, the organism doesnt change much. As seen below, tree sap may cover an organism and then turn into amber. The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in tar or ice. Molds and casts are another way organisms can be fossilized. A mold is an imprint of an organism left in rock. The organisms remains break down completely. Rock that fills in the mold resembles the original remains. The fossil that forms in the mold is called a cast. Molds and casts usually form in sedimentary rock. With compression, an organisms remains are put under great pressure inside rock layers. This leaves behind a dark stain in the rock. You can read about them in Figure 11.3. "
preserved tracks or other evidence of an organism that lived in the past,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,E,"Fossils are preserved remains or traces of organisms that lived in the past. Most preserved remains are hard parts, such as teeth, bones, or shells. Examples of these kinds of fossils are pictured in Figure 11.1. Preserved traces can include footprints, burrows, or even wastes. Examples of trace fossils are also shown in Figure 11.1. "
type of fossil that can be used to determine the age of rock layers,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,C,"Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in. Trilobite fossils, as shown in Figure 11.5, are common index fossils. Trilobites were widespread marine animals. They lived between 500 and 600 million years ago. Rock layers containing trilobite fossils must be that age. Different species of trilobite fossils can be used to narrow the age even more. "
process by which remains or traces of living things become fossils,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,F,The process by which remains or traces of living things become fossils is called fossilization. Most fossils are preserved in sedimentary rocks. 
type of fossil that forms in a mold,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,D,"Fossils may form in other ways. With complete preservation, the organism doesnt change much. As seen below, tree sap may cover an organism and then turn into amber. The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in tar or ice. Molds and casts are another way organisms can be fossilized. A mold is an imprint of an organism left in rock. The organisms remains break down completely. Rock that fills in the mold resembles the original remains. The fossil that forms in the mold is called a cast. Molds and casts usually form in sedimentary rock. With compression, an organisms remains are put under great pressure inside rock layers. This leaves behind a dark stain in the rock. You can read about them in Figure 11.3. "
any preserved remains or traces of an organism that lived in the past,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,A,"Fossils are preserved remains or traces of organisms that lived in the past. Most preserved remains are hard parts, such as teeth, bones, or shells. Examples of these kinds of fossils are pictured in Figure 11.1. Preserved traces can include footprints, burrows, or even wastes. Examples of trace fossils are also shown in Figure 11.1. "
imprint of an organism left in rock,(A) fossil (B) mold (C) index fossil (D) cast (E) trace fossil (F) fossilization (G) compression,B,"Fossils may form in other ways. With complete preservation, the organism doesnt change much. As seen below, tree sap may cover an organism and then turn into amber. The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in tar or ice. Molds and casts are another way organisms can be fossilized. A mold is an imprint of an organism left in rock. The organisms remains break down completely. Rock that fills in the mold resembles the original remains. The fossil that forms in the mold is called a cast. Molds and casts usually form in sedimentary rock. With compression, an organisms remains are put under great pressure inside rock layers. This leaves behind a dark stain in the rock. You can read about them in Figure 11.3. "
Which of the following parts of organisms are most likely to be fossilized?,(A) skin (B) hair (C) shells (D) internal organs,C,"Its very unlikely that any given organism will become a fossil. The remains of many organisms are consumed. Remains also may be broken down by other living things or by the elements. Hard parts, such as bones, are much more likely to become fossils. But even they rarely last long enough to become fossils. Organisms without hard parts are the least likely to be fossilized. Fossils of soft organisms, from bacteria to jellyfish, are very rare. "
Preserved traces of organisms might include,(A) casts (B) feces (C) molds (D) compressions,B,"Fossils are preserved remains or traces of organisms that lived in the past. Most preserved remains are hard parts, such as teeth, bones, or shells. Examples of these kinds of fossils are pictured in Figure 11.1. Preserved traces can include footprints, burrows, or even wastes. Examples of trace fossils are also shown in Figure 11.1. "
Preserved remains that have become fossils have turned to,(A) tar (B) rock (C) amber (D) none of the above,B,The process by which remains or traces of living things become fossils is called fossilization. Most fossils are preserved in sedimentary rocks. 
Which type of organisms remains are least likely to be preserved as fossils?,(A) jellyfish (B) salmon (C) shark (D) tuna,A,"Its very unlikely that any given organism will become a fossil. The remains of many organisms are consumed. Remains also may be broken down by other living things or by the elements. Hard parts, such as bones, are much more likely to become fossils. But even they rarely last long enough to become fossils. Organisms without hard parts are the least likely to be fossilized. Fossils of soft organisms, from bacteria to jellyfish, are very rare. "
Fossils can show us,(A) how extinct organisms looked (B) what past environments were like (C) what geological processes occurred in the past (D) all of the above,D,"Fossils are our best form of evidence about Earth history, including the history of life. Along with other geological evidence from rocks and structures, fossils even give us clues about past climates, the motions of plates, and other major geological events. Since the present is the key to the past, what we know about a type of organism that lives today can be applied to past environments. "
"To be used as index fossils, fossils must represent an organism that",(A) lived in the water (B) lived over a wide area (C) lived for a long period of time (D) lived less than 5 million years ago,B,"An index fossil can be used to identify a specific period of time. Organisms that make good index fossils are distinctive, widespread, and lived briefly. Their presence in a rock layer can be used to identify rocks that were deposited at that period of time over a large area. "
Earths geologic processes have changed over time.,(A) true (B) false,B,Earths climate has changed many times through Earths history. Its been both hotter and colder than it is today. 
A rocks age compared to the ages of other rocks is called its,(A) absolute age (B) confirmed age (C) nominal age (D) none of the above,D,"Early geologists had no way to determine the absolute age of a geological material. If they didnt see it form, they couldnt know if a rock was one hundred years or 100 million years old. What they could do was determine the ages of materials relative to each other. Using sensible principles they could say whether one rock was older than another and when a process occurred relative to those rocks. "
Extinction occurs when a species completely dies out.,(A) true (B) false,A,"Extinction is the complete dying out of a species. Once a species goes extinct, it can never return. More than 99 percent of all the species that ever lived on Earth have gone extinct. Five mass extinctions have occurred in Earths history. They were caused by major geologic and climatic events. The fifth mass extinction wiped out the dinosaurs 65 million years ago. "
The Law of Superposition states that,(A) younger rocks are found below older rocks (B) older rocks are found below younger rocks (C) a rock that cuts across other rocks must be younger than the rock it cuts across (D) none of the above,B,"Superposition refers to the position of rock layers and their relative ages. Relative age means age in comparison with other rocks, either younger or older. The relative ages of rocks are important for understanding Earths history. New rock layers are always deposited on top of existing rock layers. Therefore, deeper layers must be older than layers closer to the surface. This is the law of superposition. You can see an example in Figure 11.7. "
Layers of sedimentary rock are called strata.,(A) true (B) false,A,"Sedimentary rocks are formed in horizontal layers. This is magnificently displayed around the southwestern United States. The arid climate allows rock layers to be well exposed (Figure 7.4). The lowest layers are the oldest and the higher layers are younger. Folds, joints and faults are caused by stresses. Figure 7.5 shows joints in a granite hillside. If a sedimentary rock is tilted or folded, we know that stresses have changed the rock (Figure 7.6). "
The rock layers at the Grand Canyon,(A) are the same on opposite sides of the river (B) were formed in different ways on each side of the river (C) are younger than the Colorado River in that region (D) none of these,A,"The Grand Canyon provides an excellent illustration of the principles above. The many horizontal layers of sedi- mentary rock illustrate the principle of original horizontality (Figure 1.3). The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition. Distinctive rock layers, such as the Kaibab Limestone, are matched across the broad expanse of the canyon. These rock layers were once connected, as stated by the rule of lateral continuity. The Colorado River cuts through all the layers of rock to form the canyon. Based on the principle of cross- cutting relationships, the river must be younger than all of the rock layers that it cuts through. "
A good key bed must be,(A) found over a large area (B) similar to the rock units it is found with (C) a volcanic ash (D) all of these,A,"3. A key bed can be used like an index fossil since a key bed is a distinctive layer of rock that can be recognized across a large area. A volcanic ash unit could be a good key bed. One famous key bed is the clay layer at the boundary between the Cretaceous Period and the Tertiary Period, the time that the dinosaurs went extinct (Figure in asteroids. In 1980, the father-son team of Luis and Walter Alvarez proposed that a huge asteroid struck Earth 66 million years ago and caused the mass extinction. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
The relative age of a rock is its approximate age in years.,(A) true (B) false,B,"Early geologists had no way to determine the absolute age of a geological material. If they didnt see it form, they couldnt know if a rock was one hundred years or 100 million years old. What they could do was determine the ages of materials relative to each other. Using sensible principles they could say whether one rock was older than another and when a process occurred relative to those rocks. "
Rock layers on opposite sides of the Grand Canyon show lateral continuity.,(A) true (B) false,A,"Rock layers extend laterally, or out to the sides. They may cover very broad areas, especially if they formed at the bottom of ancient seas. Erosion may have worn away some of the rock, but layers on either side of eroded areas will still match up. Look at the Grand Canyon in Figure 11.8. Its a good example of lateral continuity. You can clearly see the same rock layers on opposite sides of the canyon. The matching rock layers were deposited at the same time, so they are the same age. "
A good index fossil,(A) is found in a local area (B) is distinctive (C) existed for a long period of time (D) all of these,B,"An index fossil can be used to identify a specific period of time. Organisms that make good index fossils are distinctive, widespread, and lived briefly. Their presence in a rock layer can be used to identify rocks that were deposited at that period of time over a large area. "
Key beds are rock layers that have unconformities.,(A) true (B) false,B,"Geologists can learn a lot about Earths history by studying sedimentary rock layers. But in some places, theres a gap in time when no rock layers are present. A gap in the sequence of rock layers is called an unconformity. Look at the rock layers in Figure 11.10. They show a feature called Huttons unconformity. The unconformity was discovered by James Hutton in the 1700s. Hutton saw that the lower rock layers are very old. The upper layers are much younger. There are no layers in between the ancient and recent layers. Hutton thought that the intermediate rock layers eroded away before the more recent rock layers were deposited. Huttons discovery was a very important event in geology! Hutton determined that the rocks were deposited over time. Some were eroded away. Hutton knew that deposition and erosion are very slow. He realized that for both to occur would take an extremely long time. This made him realize that Earth must be much older than people thought. This was a really big discovery! It meant there was enough time for life to evolve gradually. "
More than one type of index fossil provides stronger evidence that rock layers are the same age.,(A) true (B) false,A,"Fossils are used to determine the ages of rock layers. Index fossils are the most useful for this. Index fossils are of organisms that lived over a wide area. They lived for a fairly short period of time. An index fossil allows a scientist to determine the age of the rock it is in. Trilobite fossils, as shown in Figure 11.5, are common index fossils. Trilobites were widespread marine animals. They lived between 500 and 600 million years ago. Rock layers containing trilobite fossils must be that age. Different species of trilobite fossils can be used to narrow the age even more. "
The Cretaceous Period ended when the first dinosaurs appeared.,(A) true (B) false,B,"During the Cretaceous Period, the dinosaurs reached their maximum size and distribution. For example, the well- known Tyrannosaurus rex weighed at least 7 tons! You can get an idea of how big it was from the T. rex skeleton in Figure 7.24. (Notice how small the person looks in the bottom left of the photo.) By the end of the Cretaceous, the continents were close to their present locations. The period ended with another mass extinction. This time, the dinosaurs went extinct. What happened to the dinosaurs? Some scientists think that a comet or asteroid may have crashed into Earth. This could darken the sky, shut down photosynthesis, and cause climate change. Other factors probably contributed to the mass extinction as well. "
The earliest geologic time scale showed how many years ago each era began.,(A) true (B) false,B,"To create the geologic time scale, geologists correlated rock layers. Stenos laws were used to determine the relative ages of rocks. Older rocks are at the bottom and younger rocks are at the top. The early geologic time scale could only show the order of events. The discovery of radioactivity in the late 1800s changed that. Scientists could determine the exact age of some rocks in years. They assigned dates to the time scale divisions. For example, the Jurassic began about 200 million years ago. It lasted for about 55 million years. "
Fish were common organisms during the Paleozoic Era.,(A) true (B) false,A,"Paleozoic life was most diverse in the oceans. Paleozoic seas were full of worms, snails, clams, trilobites, sponges, and brachiopods. Organisms with shells were common. The first fish were simple, armored, jawless fish. Fish have internal skeletons. Some, like sharks, skates, and rays, have skeletons of cartilage. More advanced fish have skeletons of bones. Fish evolved jaws and many other adaptations for ocean life. Figure 12.13 shows some of the diversity of Earths oceans. "
"Fossil B is younger than Fossil A, but the rock layer containing Fossil B is beneath the rock layer",(A) true (B) false,A,"Other scientists observed rock layers and formulated other principles. Geologist William Smith (1769-1839) identified the principle of faunal succession, which recognizes that: Some fossil types are never found with certain other fossil types (e.g. human ancestors are never found with dinosaurs) meaning that fossils in a rock layer represent what lived during the period the rock was deposited. Older features are replaced by more modern features in fossil organisms as species change through time; e.g. feathered dinosaurs precede birds in the fossil record. Fossil species with features that change distinctly and quickly can be used to determine the age of rock layers quite precisely. Scottish geologist, James Hutton (1726-1797) recognized the principle of cross-cutting relationships. This helps geologists to determine the older and younger of two rock units (Figure 1.2). If an igneous dike (B) cuts a series of metamorphic rocks (A), which is older and which is younger? In this image, A must have existed first for B to cut across it. "
"To help decipher the geologic history of a region, create a geologic time scale using the rock units you",(A) true (B) false,B,"To be able to discuss Earth history, scientists needed some way to refer to the time periods in which events happened and organisms lived. With the information they collected from fossil evidence and using Stenos principles, they created a listing of rock layers from oldest to youngest. Then they divided Earths history into blocks of time with each block separated by important events, such as the disappearance of a species of fossil from the rock record. Since many of the scientists who first assigned names to times in Earths history were from Europe, they named the blocks of time from towns or other local places where the rock layers that represented that time were found. From these blocks of time the scientists created the geologic time scale (Figure 1.1). In the geologic time scale the youngest ages are on the top and the oldest on the bottom. Why do you think that the more recent time periods are divided more finely? Do you think the divisions in the scale below are proportional to the amount of time each time period represented in Earth history? In what eon, era, period and epoch do we now live? We live in the Holocene (sometimes called Recent) epoch, Quaternary period, Cenozoic era, and Phanerozoic eon. "
James Hutton thought Earth was old because he saw how slowly geological processes work now.,(A) true (B) false,A,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
Cross-cutting relationships help geologists to determine the older and younger of two rock units.,(A) true (B) false,A,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
"In the process of relative dating, scientists determine the exact age of a fossil or rock.",(A) true (B) false,B,"Fossils are useful for reconstructing the past only if they can be dated. Scientists need to determine when the organisms lived who left behind the fossils. Fossils can be dated in two different ways: absolute dating and relative dating. Absolute dating determines about how long ago a fossil organism lived. This gives the fossil an approximate age in years. Absolute dating is often based on the amount of carbon-14 or other radioactive element that remains in a fossil. You can learn how carbon-14 dating works by watching this short video: Relative dating determines which of two fossils is older or younger than the other but not their age in years. Relative dating is based on the positions of fossils in rock layers. Lower rock layers were laid down earlier, so they are assumed to contain older fossils. This is illustrated in Figure 7.9. "
whether a rock is older or younger than other rocks,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,C,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
law stating that rock layers are deposited in horizontal layers,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,E,"Sediments were deposited in ancient seas in horizontal, or flat, layers. If sedimentary rock layers are tilted, they must have moved after they were deposited. "
law stating that rock layers closer to the surface are younger than deeper rock layers,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,B,"Superposition refers to the position of rock layers and their relative ages. Relative age means age in comparison with other rocks, either younger or older. The relative ages of rocks are important for understanding Earths history. New rock layers are always deposited on top of existing rock layers. Therefore, deeper layers must be older than layers closer to the surface. This is the law of superposition. You can see an example in Figure 11.7. "
law stating that rock layers are older than any rocks that cut across them,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,F,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
gap in a sequence of rock layers,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,G,"Rock layers extend laterally, or out to the sides. They may cover very broad areas, especially if they formed at the bottom of ancient seas. Erosion may have worn away some of the rock, but layers on either side of eroded areas will still match up. Look at the Grand Canyon in Figure 11.8. Its a good example of lateral continuity. You can clearly see the same rock layers on opposite sides of the canyon. The matching rock layers were deposited at the same time, so they are the same age. "
law stating that matching nearby rock layers are the same age,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,D,"Superposition refers to the position of rock layers and their relative ages. Relative age means age in comparison with other rocks, either younger or older. The relative ages of rocks are important for understanding Earths history. New rock layers are always deposited on top of existing rock layers. Therefore, deeper layers must be older than layers closer to the surface. This is the law of superposition. You can see an example in Figure 11.7. "
study of rock layers,(A) stratigraphy (B) superposition (C) relative age (D) lateral continuity (E) original horizontality (F) cross-cutting relationships (G) unconformity,A,The study of rock strata is called stratigraphy. The laws of stratigraphy can help scientists understand Earths past. The laws of stratigraphy are usually credited to a geologist from Denmark named Nicolas Steno. He lived in the 1600s. The laws are illustrated in Figure 11.6. Refer to the figure as you read about the laws below. 
"If sedimentary rock layers are tilted, they must have",(A) formed at an angle (B) moved after they formed (C) been cross-cut by igneous rock (D) formed from deposits on a mountainside,B,"Sediments were deposited in ancient seas in horizontal, or flat, layers. If sedimentary rock layers are tilted, they must have moved after they were deposited. "
A key bed of clay from around the time the dinosaurs went extinct led to the hypothesis that the extinction was caused by a,(A) large flood (B) huge volcano (C) giant asteroid (D) none of the above,C,"3. A key bed can be used like an index fossil since a key bed is a distinctive layer of rock that can be recognized across a large area. A volcanic ash unit could be a good key bed. One famous key bed is the clay layer at the boundary between the Cretaceous Period and the Tertiary Period, the time that the dinosaurs went extinct (Figure in asteroids. In 1980, the father-son team of Luis and Walter Alvarez proposed that a huge asteroid struck Earth 66 million years ago and caused the mass extinction. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Evidence shows that Earth is about,(A) 19 million years old (B) 28 million years old (C) 38 billion years old (D) 45 billion years old,D,"How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists, and naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: Fossils of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans. The many layers of rock. When people realized that rock layers represent the order in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth. Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earths surface. This supported the idea of an older Earth. The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years. "
Eons of the geologic time scale are divided first into,(A) years (B) periods (C) eras (D) epochs,C,"The largest blocks of time on the geologic time scale are called eons. Eons are split into eras. Each era is divided into periods. Periods may be further divided into epochs. Geologists may just use early or late. An example is late Jurassic, or early Cretaceous. Figure 11.13 shows you what the geologic time scale looks like. "
The Cenozoic Era is called the age of,(A) dinosaurs (B) mammals (C) reptiles (D) life,B,"We now live in the Phanerozoic Eon, the Cenozoic Era, the Quaternary Period, and the Holocene Epoch. Phanero- zoic means visible life. During this eon, rocks contain visible fossils. Before the Phanerozoic, life was microscopic. The Cenozoic Era means new life. It encompasses the most recent forms of life on Earth. The Cenozoic is sometimes called the Age of Mammals. Before the Cenozoic came the Mesozoic and Paleozoic. The Mesozoic means middle life. This is the age of reptiles, when dinosaurs ruled the planet. The Paleozoic is old life. Organisms like invertebrates and fish were the most common lifeforms. "
What does the term paleozoic mean?,(A) fossil life (B) ancient rock (C) rock strata (D) old life,D,"The Paleozoic is the furthest back era of the Phanerozoic and it lasted the longest. But the Paleozoic was relatively recent, beginning only 570 million years ago. Compared with the long expanse of the Precambrian, the Phanerozoic is recent history. Much more geological evidence is available for scientists to study so the Phanerozoic is much better known. The Paleozoic begins and ends with a supercontinent. At the beginning of the Paleozoic, the supercontinent Rodinia began to split up. At the end, Pangaea came together. "
Many of the divisions of the geologic time scale mark major events in the history of,(A) life (B) science (C) astronomy (D) Earth science,A,"Another tool for understanding the history of Earth and its life is the geologic time scale. You can see this time scale in Figure 7.18. It divides Earths history into eons, eras, and periods. These divisions are based on major changes in geology, climate, and the evolution of life. The geologic time scale organizes Earths history on the basis of important events instead of time alone. It also puts more focus on recent events, about which we know the most. "
How much percent of the parent isotope remains after 2 half-lives?,(A) 100% (B) 50% (C) 25% (D) 75%,C,"Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL: "
The half-life of a radioactive element is,(A) half the estimated age of Earths crust (B) the time it takes for half a parent isotope to decay into the daughter isotope (C) half the weight of the original radioactive element (D) the time it takes for half of a daughter isotope to decay into a parent isotope,B,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
Carbon dating is useful for,(A) igneous rocks (B) sedimentary rocks (C) organic materials (D) none of the above,C,"Radiocarbon dating is used to find the age of once-living materials between 100 and 50,000 years old. This range is especially useful for determining ages of human fossils and habitation sites (Figure 1.1). The atmosphere contains three isotopes of carbon: carbon-12, carbon-13 and carbon-14. Only carbon-14 is radioac- tive; it has a half-life of 5,730 years. The amount of carbon-14 in the atmosphere is tiny and has been relatively stable through time. Plants remove all three isotopes of carbon from the atmosphere during photosynthesis. Animals consume this carbon when they eat plants or other animals that have eaten plants. After the organisms death, the carbon-14 decays to stable nitrogen-14 by releasing a beta particle. The nitrogen atoms are lost to the atmosphere, but the amount of carbon-14 that has decayed can be estimated by measuring the proportion of radioactive carbon-14 to stable carbon- 12. As time passes, the amount of carbon-14 decreases relative to the amount of carbon-12. Carbon isotopes from the black material in these cave paintings places their cre- ating at about 26,000 to 27,000 years BP (before present). "
Potassium-argon is better for dating igneous rocks than carbon-14 because,(A) the argon-39 half life is short (B) the potassium-40 half-life is long (C) igneous rocks do not contain carbon (D) all of these,B,"The isotopes in Table 11.1 are used to date igneous rocks. These isotopes have much longer half-lives than carbon- 14. Because they decay more slowly, they can be used to date much older specimens. Which of these isotopes could be used to date a rock that formed half a million years ago? Unstable Isotope Decays to At a Half-Life of (years) Potassium-40 Uranium-235 Uranium-238 Argon-40 Lead-207 Lead-206 1.3 billion 700 million 4.5 billion Dates Rocks Aged (years old) 100 thousand - 1 billion 1 million - 4.5 billion 1 million - 4.5 billion "
"For radiometric dating of Earths oldest rocks, it is best to use",(A) uranium-238 to lead-206 (B) potassium-argon (C) radiocarbon (D) none of these,A,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
The number of protons in atoms of the same element may vary.,(A) true (B) false,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
Almost all carbon atoms are atoms of carbon-14.,(A) true (B) false,B,"Find carbon in the Figure 1.1, and youll see that its atomic number is 6. This means that all carbon atoms have 6 protons per nucleus. Almost all carbon atoms also have 6 neutrons per nucleus. These carbon atoms are called carbon-12, where 12 is the number of protons (6) plus neutrons (6). This gives carbon-12 nuclei a 1:1 ratio of protons to neutrons, so carbon-12 nuclei are stable. Some carbon atoms have more than 6 neutrons, either 7 or 8. Carbon atoms with 8 neutrons are called carbon-14 (6 protons + 8 neutrons). The nuclei of carbon-14 atoms are unstable because they have too many neutrons relative to protons, so they gradually decay. Q: What is the proton-to-neutron ratio of carbon-14 nuclei? A: With six protons and 8 neutrons, the ratio is 6:8, or 1:1.3. Q: How is carbon-14 used to estimate the ages of fossils? A: Living things take in carbon, including tiny amounts of carbon-14, throughout life. The carbon-14 constantly decays, but more carbon-14 is taken in all the time to replace it. After living things die, no new carbon-14 is taken in, and the carbon-14 they already have keeps decaying. The older a fossil is, the less carbon-14 it still has, so the remaining amount can be measured to estimate the fossils age. Click image to the left or use the URL below. URL:  Periodic Table of the Elements "
"When an atom of carbon-14 decays, it loses an electron.",(A) true (B) false,B,"Like other unstable isotopes, carbon-14 breaks down, or decays. For carbon-14 decay, each carbon-14 atom loses an alpha particle. It changes to a stable atom of nitrogen-14. This is illustrated in Figure 11.17. The decay of an unstable isotope to a stable element occurs at a constant rate. This rate is different for each isotope pair. The decay rate is measured in a unit called the half-life. The half-life is the time it takes for half of a given amount of an isotope to decay. For example, the half-life of carbon-14 is 5730 years. Imagine that you start out with 100 grams of carbon-14. In 5730 years, half of it decays. This leaves 50 grams of carbon-14. Over the next 5730 years, half of the remaining amount will decay. Now there are 25 grams of carbon-14. How many grams will there be in another 5730 years? Figure 11.18 graphs the rate of decay of carbon-14. "
Using radioactivity scientists are able to measure the relative age of some rocks.,(A) true (B) false,B,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
Carbon-14 atoms decay to carbon-13 atoms.,(A) true (B) false,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
Radioactive isotopes gain or lose particles to become different elements.,(A) true (B) false,A,"Radioactive elements and isotopes have unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei give off, or emit, radiation in the form of energy and often particles as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. "
The half-life of a radioactive isotope is constant.,(A) true (B) false,A,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
A living thing takes in carbon-14 only while it is alive.,(A) true (B) false,A,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
No one knows Earths age because no isotopes are good for substances that old.,(A) true (B) false,B,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
Carbon-14 dating can be used to determine the ages of rocks.,(A) true (B) false,B,Radioactive isotopes can be used to estimate the ages of fossils and rocks. The method is called radioactive dating. Carbon-14 dating is an example of radioactive dating. It is illustrated in the video at this URL:  MEDIA Click image to the left or use the URL below. URL: 
"Carbon-14 loses an alpha particle, which is two protons and two electrons.",(A) true (B) false,B,"Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure 1.1 shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus. Losing the protons and neutrons makes the nucleus more stable. "
Plants take in carbon-14 during photosynthesis.,(A) true (B) false,A,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
The half-life of carbon-14 is 5730 years.,(A) true (B) false,A,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
All fossils can be dated with carbon-14 dating.,(A) true (B) false,B,"Carbon-14 has a relatively short half-life (see Table 11.1). After about 50,000 years, too little carbon-14 is left in a fossil to be measured. Therefore, carbon-14 dating can only be used to date fossils that are less than 50,000 years old. Radioisotopes with a longer half-life, such as potassium-40, must be used to date older fossils and rocks. "
"To date a rock that is as old as Earth, you could use potassium-40 dating.",(A) true (B) false,B,"Potassium-40 decays to argon-40 with a half-life of 1.26 billion years. Argon is a gas so it can escape from molten magma, meaning that any argon that is found in an igneous crystal probably formed as a result of the decay of potassium-40. Measuring the ratio of potassium-40 to argon-40 yields a good estimate of the age of that crystal. Potassium is common in many minerals, such as feldspar, mica, and amphibole. With its half-life, the technique is used to date rocks from 100,000 years to over a billion years old. The technique has been useful for dating fairly young geological materials and deposits containing the bones of human ancestors. "
Absolute ages are based on evidence from,(A) key beds (B) stratigraphy (C) index fossils (D) radiometric dating,D,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
Which of the following atomic particles may vary for atoms of a given element?,(A) protons (B) neutrons (C) electrons (D) all of the above,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
How many protons are found in each atom of carbon-14?,(A) 14 (B) 8 (C) 7 (D) 6,D,"Find carbon in the Figure 1.1, and youll see that its atomic number is 6. This means that all carbon atoms have 6 protons per nucleus. Almost all carbon atoms also have 6 neutrons per nucleus. These carbon atoms are called carbon-12, where 12 is the number of protons (6) plus neutrons (6). This gives carbon-12 nuclei a 1:1 ratio of protons to neutrons, so carbon-12 nuclei are stable. Some carbon atoms have more than 6 neutrons, either 7 or 8. Carbon atoms with 8 neutrons are called carbon-14 (6 protons + 8 neutrons). The nuclei of carbon-14 atoms are unstable because they have too many neutrons relative to protons, so they gradually decay. Q: What is the proton-to-neutron ratio of carbon-14 nuclei? A: With six protons and 8 neutrons, the ratio is 6:8, or 1:1.3. Q: How is carbon-14 used to estimate the ages of fossils? A: Living things take in carbon, including tiny amounts of carbon-14, throughout life. The carbon-14 constantly decays, but more carbon-14 is taken in all the time to replace it. After living things die, no new carbon-14 is taken in, and the carbon-14 they already have keeps decaying. The older a fossil is, the less carbon-14 it still has, so the remaining amount can be measured to estimate the fossils age. Click image to the left or use the URL below. URL:  Periodic Table of the Elements "
"If a carbon atom has 7 neutrons, it is the isotope named",(A) carbon-11 (B) carbon-12 (C) carbon-13 (D) carbon-14,C,"For most other elements, isotopes are named for their mass number. For example, carbon atoms with the usual 6 neutrons have a mass number of 12 (6 protons + 6 neutrons = 12), so they are called carbon-12. Carbon atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms are the isotope called carbon-13. Some carbon atoms have 8 neutrons. What is the name of this isotope of carbon? You can learn more about this isotope at the URL below. It is used by scientists to estimate the ages of rocks and fossils. "
Plants use carbon dioxide for the process of,(A) respiration (B) germination (C) reproduction (D) photosynthesis,D,Producers such as plants or algae use carbon dioxide in the air to make food. The organisms combine carbon dioxide with water to make sugar. They store the sugar as starch. Both sugar and starch are carbohydrates. Consumers get carbon when they eat producers or other consumers. Carbon doesnt stop there. Living things get energy from food in a process called respiration. This releases carbon dioxide back into the atmosphere. The cycle then repeats. 
New atoms of carbon-14 form in the atmosphere because of,(A) pollution (B) cosmic rays (C) global warming (D) burning of fossil fuels,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
"If you start with 1.00 g of carbon-14, the amount left after two half-lives will be",(A) 0 g (B) 025 g (C) 050 g (D) 075 g,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
using radioactive decay to estimate the age of a fossil or rock,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,G,The rate of decay of unstable isotopes can be used to estimate the absolute ages of fossils and rocks. This type of dating is called radiometric dating. 
radioactive element with a relatively long half-life,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,D,"Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL: "
rate of decay of a radioactive element,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,F,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
atom of an element with a different number of neutrons,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,A,"Some atoms of the same element may have different numbers of neutrons. For example, some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in number of neutrons are called isotopes. Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same chemical properties. Thats because they have the same numbers of protons and electrons. For a video explanation of isotopes, go to this URL:  MEDIA Click image to the left or use the URL below. URL: "
stable isotope of carbon,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,C,"Radiocarbon dating is used to find the age of once-living materials between 100 and 50,000 years old. This range is especially useful for determining ages of human fossils and habitation sites (Figure 1.1). The atmosphere contains three isotopes of carbon: carbon-12, carbon-13 and carbon-14. Only carbon-14 is radioac- tive; it has a half-life of 5,730 years. The amount of carbon-14 in the atmosphere is tiny and has been relatively stable through time. Plants remove all three isotopes of carbon from the atmosphere during photosynthesis. Animals consume this carbon when they eat plants or other animals that have eaten plants. After the organisms death, the carbon-14 decays to stable nitrogen-14 by releasing a beta particle. The nitrogen atoms are lost to the atmosphere, but the amount of carbon-14 that has decayed can be estimated by measuring the proportion of radioactive carbon-14 to stable carbon- 12. As time passes, the amount of carbon-14 decreases relative to the amount of carbon-12. Carbon isotopes from the black material in these cave paintings places their cre- ating at about 26,000 to 27,000 years BP (before present). "
radioactive element with a relatively short half-life,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,B,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
breakdown of unstable elements into stable elements,(A) isotope (B) carbon-14 (C) carbon-12 (D) uranium-238 (E) radioactive decay (F) half-life (G) radiometric dating,E,"Radioactive decay is the breakdown of unstable elements into stable elements. To understand this process, recall that the atoms of all elements contain the particles protons, neutrons, and electrons. "
ring of icy debris just beyond Neptune,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,F,"Like the other outer planets, Neptune has rings of ice and dust. These rings are much thinner and fainter than Saturns. Neptunes rings may be unstable. They may change or disappear in a relatively short time. Neptune has 13 known moons. Only Triton, shown in Figure 25.30, has enough mass to be round. Triton orbits in the direction opposite to Neptunes orbit. Scientists think Triton did not form around Neptune. The satellite was captured by Neptunes gravity as it passed by. "
Before the Sun formed,(A) temperature and pressure was extreme (B) radioactivity began (C) the planets formed (D) all of the above,A,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
example of an object in the solar system,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,C,"Since the time of Copernicus, Kepler, and Galileo, we have learned a lot more about our solar system. Astronomers have discovered two more planets (Uranus and Neptune), five dwarf planets (Ceres, Pluto, Makemake, Haumea, and Eris), more than 150 moons, and many, many asteroids and other small objects. Although the Sun is just an average star compared to other stars, it is by far the largest object in the solar system. The Sun is more than 500 times the mass of everything else in the solar system combined! Table 1.1 gives data on the sizes of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter Object Mass (Relative to Earth) Mars Jupiter Saturn Uranus Neptune 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass 17.2 Earths mass Diameter of Planet (Relative to Earth) 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter 3.81 Earths diameter "
The densest part of planet Earth is the,(A) continental crust (B) oceanic crust (C) core (D) mantle,C,"When Earth was entirely molten, gravity drew denser elements to the center and lighter elements rose to the surface. The separation of Earth into layers based on density is known as differentiation. The densest material moved to the center to create the planets dense metallic core. Materials that are intermediate in density became part of the mantle (Figure 1.1). "
water in the gaseous state,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,E,"The photo above represents water in three common states of matter. States of matter are different phases in which any given type of matter can exist. There are actually four well-known states of matter: solid, liquid, gas, and plasma. Plasma isnt represented in the iceberg photo, but the other three states of matter are. The iceberg itself consists of water in the solid state, and the lake consists of water in the liquid state. Q: Where is water in the gaseous state in the above photo? A: You cant see the gaseous water, but its there. It exists as water vapor in the air. Q: Water is one of the few substances that commonly exist on Earth in more than one state. Many other substances typically exist only in the solid, liquid, or gaseous state. Can you think of examples of matter that usually exists in just one of these three states? A: Just look around you and you will see many examples of matter that usually exists in the solid state. They include soil, rock, wood, metal, glass, and plastic. Examples of matter that usually exist in the liquid state include cooking oil, gasoline, and mercury, which is the only metal that commonly exists as a liquid. Examples of matter that usually exists in the gaseous state include oxygen and nitrogen, which are the chief gases in Earths atmosphere. "
The Sun formed from,(A) a spinning cloud of gas and dust (B) large dense planets pulled to the center by gravity (C) radioactive dust that ignited (D) a collision by two stars,A,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
When the solar system first formed,(A) life forms were primitive (B) asteroid impacts were common (C) each planets was surrounded by a thick atmosphere (D) all of these,B,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
gas missing from Earths early atmosphere,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,G,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
reaction in which hydrogen atoms change to helium,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,B,"Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. Thats because a great deal of energy is needed to overcome the force of repulsion between positively charged nuclei. The suns energy comes from fusion in its core, where temperatures reach millions of Kelvin (see Figure 11.16). "
Gases in the first atmosphere came from,(A) comet impact (B) volcanic outgassing (C) none of these (D) both of these,D,"Earths first atmosphere was different from the current one. The gases came from two sources. Volcanoes spewed gases into the air. Comets carried in ices from outer space. These ices warmed and became gases. Nitrogen, carbon dioxide, hydrogen, and water vapor, or water in gas form, were in the first atmosphere (Figure 12.5). Take a look at the list of gases. Whats missing? The early atmosphere had almost no oxygen. "
giant cloud of gas and dust from which the solar system formed,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,D,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
gases that surround a planet,(A) atmosphere (B) nuclear fusion (C) comet (D) solar nebula (E) water vapor (F) Kuiper belt (G) oxygen,A,An atmosphere is the gases that surround a planet. The early Earth had no atmosphere. Conditions were so hot that gases were not stable. 
The solar system formed from a giant mass of gas and dust.,(A) true (B) false,A,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
The sun formed billions of years before other objects in the solar system.,(A) true (B) false,B,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
The solar nebula formed a disk before it formed the sun.,(A) true (B) false,A,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
"The first atmosphere contained nitrogen, carbon dioxide, oxygen, and hydrogen.",(A) true (B) false,B,"Earths first atmosphere was different from the current one. The gases came from two sources. Volcanoes spewed gases into the air. Comets carried in ices from outer space. These ices warmed and became gases. Nitrogen, carbon dioxide, hydrogen, and water vapor, or water in gas form, were in the first atmosphere (Figure 12.5). Take a look at the list of gases. Whats missing? The early atmosphere had almost no oxygen. "
Objects in our solar system include dwarf planets.,(A) true (B) false,A,"The dwarf planets of our solar system are exciting proof of how much we are learning about our solar system. With the discovery of many new objects in our solar system, astronomers refined the definition of a dwarf planet in 2006. According to the IAU, a dwarf planet must: Orbit a star. Have enough mass to be nearly spherical. Not have cleared the area around its orbit of smaller objects. Not be a moon. "
All of the stars in the Universe formed at around the same time as our Sun.,(A) true (B) false,B,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
"As Earth formed, gravity pulled lighter materials to the center of the planet.",(A) true (B) false,B,"When Earth was entirely molten, gravity drew denser elements to the center and lighter elements rose to the surface. The separation of Earth into layers based on density is known as differentiation. The densest material moved to the center to create the planets dense metallic core. Materials that are intermediate in density became part of the mantle (Figure 1.1). "
Earths mantle is made entirely of liquid rock.,(A) true (B) false,B,"The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. "
"The Sun, planets and other solar system objects formed at about the same time.",(A) true (B) false,A,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
There was a lot of space debris in the early solar system.,(A) true (B) false,A,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
Early Earth was much like Earth today.,(A) true (B) false,B,"Since the early Earth was very hot, mantle convection was very rapid. Plate tectonics likely moved very quickly. The early Earth was a very active place with abundant volcanic eruptions and earthquakes. The remnants of these early rocks are now seen in the ancient cores of the continents. "
"Before there was an ocean, there was water vapor in the atmosphere.",(A) true (B) false,A,"The early atmosphere was rich in water vapor from volcanic eruptions and comets. When Earth was cool enough, water vapor condensed and rain began to fall. The water cycle began. Over millions of years enough precipitation collected that the first oceans could have formed as early as 4.2 to 4.4 billion years ago. Dissolved minerals carried by stream runoff made the early oceans salty. What geological evidence could there be for the presence of an early ocean? Marine sedimentary rocks can be dated back about 4 billion years. By the Archean, the planet was covered with oceans and the atmosphere was full of water vapor, carbon dioxide, nitrogen, and smaller amounts of other gases. Click image to the left or use the URL below. URL: "
Earths moon began as a dwarf planet orbiting the sun.,(A) true (B) false,B,Material at a similar distances from the Sun collided together to form each of the planets. Earth grew from material in its part of space. Moons origin was completely different from Earths. 
"From the time it first formed, Earth has always had an atmosphere.",(A) true (B) false,B,An atmosphere is the gases that surround a planet. The early Earth had no atmosphere. Conditions were so hot that gases were not stable. 
Some of the gases in Earths early atmosphere came from comets.,(A) true (B) false,A,"Earths first atmosphere was different from the current one. The gases came from two sources. Volcanoes spewed gases into the air. Comets carried in ices from outer space. These ices warmed and became gases. Nitrogen, carbon dioxide, hydrogen, and water vapor, or water in gas form, were in the first atmosphere (Figure 12.5). Take a look at the list of gases. Whats missing? The early atmosphere had almost no oxygen. "
Our solar system began to form about,(A) 3 billion years ago (B) 4 billion years ago (C) 5 billion years ago (D) 10 billion years ago,C,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
"When the solar nebula contracted and began to spin, it",(A) increased in temperature (B) increased in pressure (C) formed into a disk (D) all of the above,D,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
The inner planets of our solar system include,(A) Pluto (B) Uranus (C) Saturn (D) Mercury,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
"After the sun formed, material at similar distances from the sun collided to form each of the",(A) moons (B) planets (C) asteroids (D) comets,B,Material at a similar distances from the Sun collided together to form each of the planets. Earth grew from material in its part of space. Moons origin was completely different from Earths. 
Earth formed about,(A) 45 billion years ago (B) 3 billion years ago (C) 1 billion years ago (D) 05 billion years ago,A,"Earth came together (accreted) from the cloud of dust and gas known as the solar nebula nearly 4.6 billion years ago, the same time the Sun and the rest of the solar system formed. Gravity caused small bodies of rock and metal orbiting the proto-Sun to smash together to create larger bodies. Over time, the planetoids got larger and larger until they became planets. "
Gases in Earths early atmosphere included,(A) oxygen (B) water vapor (C) carbon dioxide (D) all of the above,D,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
"After the oceans formed on Earths surface, the",(A) water cycle began (B) atmosphere formed (C) mantle started to cool (D) all of the above,A,"When Earth first formed, it was a fiery hot, barren ball. It had no oceans or atmosphere. Rivers of melted rock flowed over its surface. Gradually, the planet cooled and formed a solid crust. Gases from volcanoes formed an atmosphere, although it contained only a trace of oxygen. As the planet continued to cool, clouds formed and rain fell. Rainwater helped form oceans. The ancient atmosphere and oceans would be toxic to modern life, but they set the stage for life to begin. "
The fourth supercontinent to form was,(A) Pangaea (B) Rodinia (C) Escherichia (D) none of the above,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
Earths first crust was probably made of,(A) anorthosite (B) granite (C) basalt (D) peridotite,B,"The first crust was made of basaltic rock, like the current ocean crust. Partial melting of the lower portion of the basaltic crust began more than 4 billion years ago. This created the silica-rich crust that became the felsic continents. "
The supercontinent in question 1 formed about,(A) 50 billion years ago (B) 45 billion years ago (C) 40 billion years ago (D) 11 billion years ago,D,"By the end of the Archean, about 2.5 billion years ago, plate tectonics processes were completely recognizable. Small Proterozoic continents known as microcontinents collided to create supercontinents, which resulted in the uplift of massive mountain ranges. The history of the North American craton is an example of what generally happened to the cratons during the Precambrian. As the craton drifted, it collided with microcontinents and oceanic island arcs, which were added to the continents. Convergence was especially active between 1.5 and 1.0 billion years ago. These lands came together to create the continent of Laurentia. About 1.1 billion years ago, Laurentia became part of the supercontinent Rodinia (Figure 1.1). Rodinia probably contained all of the landmass at the time, which was about 75% of the continental landmass present today. Rodinia broke up about 750 million years ago. The geological evidence for this breakup includes large lava flows that are found where continental rifting took place. Seafloor spreading eventually started and created the oceans between the continents. The breakup of Rodinia may have triggered Snowball Earth around 700 million years ago. "
The earliest life on Earth,(A) may have been wiped out more than once (B) got its nutrients from photosynthesis (C) passed genetic information using amino acids (D) all of these,A,For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. 
Early Earth had,(A) many volcanoes (B) high temperatures (C) abundant earthquakes (D) all of the above,D,"When Earth formed 4.6 billion years ago, it would not have been called the water planet. There were no oceans then. In fact, there was no liquid water at all. Early Earth was too hot for liquid water to exist. Earths early years were spent as molten rock and metal. "
How do cells make copies of themselves?,(A) Nucleic acids pass on genetic information (B) Using their metabolism (C) By combining cells to become multi-cellular (D) None of these,A,"Prokaryotes reproduce asexually. This can happen by binary fission or budding. In binary fission, a cell splits in two. First, the large circular chromosome is copied. Then the cell divides to form two new daughter cells. Each has a copy of the parent cells chromosome. In budding, a new cell grows from a bud on the parent cell. It only breaks off to form a new cell when it is fully formed. "
Which of the following is true?,(A) Prokaryotes and eukaryotes are both only single celled (B) Prokaryotes are only single-celled; eukaryotes are only multicellular (C) Prokaryotes are single-celled or multicellular; eukaryotes are only multicellular (D) Prokaryotes and eukaryotes both are single-celled or multicellular,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
Earths earliest life forms,(A) consisted of one cell (B) could breathe oxygen (C) lacked a cell membrane (D) none of the above,A,There is good evidence that life has probably existed on Earth for most of Earths history. Fossils of blue-green algae found in Australia are the oldest fossils of life forms on Earth. They are at least 3.5 billion years old ( Figure 1.1). 
The earliest organisms to photosynthesize,(A) first appeared about a billion years ago (B) went extinct millions of years ago (C) are still common in lakes and seas (D) two of the above,C,The first organisms to photosynthesize were cyanobacteria. These organisms may have been around as far back as 3.5 billion years and are still alive today (Figure 12.7). Now they are called blue-green algae. They are common in lakes and seas and account for 20% to 30% of photosynthesis today. 
Continents form when,(A) seafloor spreading creates them (B) Earth melts and then re-solidifies (C) microcontinents or island arcs collide (D) none of these,C,"Continents grow when microcontinents, or small continents, collide with each other or with a larger continent. Oceanic island arcs also collide with continents to make them grow. "
Eukaryotes first evolved about,(A) 45 billion years ago (B) 35 billion years ago (C) 20 billion years ago (D) 05 billion years ago,C,"Eukaryotes evolved about 2 billion years ago. Unlike prokaryotes, eukaryotes have a cell nucleus. They have more structures and are better organized. Organelles within a eukaryote can perform certain functions. Some supply energy; some break down wastes. Eukaryotes were better able to live and so became the dominant life form. "
Which of the following types of organisms evolved first?,(A) multicellular organisms (B) Ediacara fauna (C) cyanobacteria (D) eukaryotes,C,"Bacteria are the most successful organisms on the planet. They lived on this planet for two billion years before the first eukaryotes and, during that time, evolved into millions of different species. "
Prokaryoes are more common than eukaryotes.,(A) true (B) false,B,"Most prokaryotic cells are much smaller than eukaryotic cells. Prokaryotic cells are typically only 0.2-2.0 microm- eter in diameter. Eukaryotic cells are about 50 times as big. Prokaryotic cells have a variety of different cell shapes. Figure 8.3 shows three of the most common shapes: spirals (helices), spheres, and rods. Bacteria may be classified by their shape. "
DNA is short for deoxyribonucleic acid,(A) true (B) false,A,"DNA is the material that makes up our chromosomes and stores our genetic information. When you build a house, you need a blueprint, a set of instructions that tells you how to build. The DNA is like the blueprint for living organisms. The genetic information is a set of instructions that tell your cells what to do. DNA is an abbreviation for deoxyribonucleic acid. As you may recall, nucleic acids are a type of macromolecule that store information. The deoxyribo part of the name refers to the name of the sugar that is contained in DNA, deoxyribose. DNA may provide the instructions to make up all living things, but it is actually a very simple molecule. DNA is made of a very long chain of nucleotides. In fact, in you, the smallest DNA molecule has well over 20 million nucleotides. "
Rodinia was the first supercontinent.,(A) true (B) false,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
Early in Earth history mantle convection was super fast.,(A) true (B) false,A,"Since the early Earth was very hot, mantle convection was very rapid. Plate tectonics likely moved very quickly. The early Earth was a very active place with abundant volcanic eruptions and earthquakes. The remnants of these early rocks are now seen in the ancient cores of the continents. "
The evolution from prokaryotes to eukaryotes to multi-cellular organisms took a few million years.,(A) true (B) false,B,"For life to evolve from simple single-celled organisms to many millions of species of prokaryotic species to simple eukaryotic species to all the protists, fungi, plants, and animals, took some time. Well over 3 billion years. "
Nucleic acids in living things include DNA and RNA.,(A) true (B) false,A,"Nucleic acids are biochemical molecules that contain oxygen, nitrogen, and phosphorus in addition to carbon and hydrogen. There are two main types of nucleic acids. They are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). "
Continental crust first appeared on Earth about 2 billion years ago.,(A) true (B) false,B,"The earliest crust was probably basalt. It may have resembled the current seafloor. This crust formed before there were any oceans. More than 4 billion years ago, continental crust appeared. The first continents were very small compared with those today. "
The first continents on Earth were very large compared with those today.,(A) true (B) false,B,"The earliest crust was probably basalt. It may have resembled the current seafloor. This crust formed before there were any oceans. More than 4 billion years ago, continental crust appeared. The first continents were very small compared with those today. "
Pangaea was the first supercontinent to form on Earth.,(A) true (B) false,B,"Pangaea was the last supercontinent on Earth. Evidence for the existence of Pangaea was what Alfred Wegener used to create his continental drift hypothesis, which was described in the chapter Plate Tectonics. As the continents move and the land masses change shape, the shape of the oceans changes too. During the time of Pangaea, about 250 million years ago, most of Earths water was collected in a huge ocean called Panthalassa (Figure 1.2). Click image to the left or use the URL below. URL: "
Life may have originated on Earth more than once.,(A) true (B) false,A,"No one knows how or when life first began on the turbulent early Earth. There is little hard evidence from so long ago. Scientists think that it is extremely likely that life began and was wiped out more than once; for example, by the impact that created the Moon. This issue of whats living and whats not becomes important when talking about the origin of life. If were going to know when a blob of organic material crossed over into being alive, we need to have a definition of life. "
The first oxygen on Earth combined with iron to form iron oxide.,(A) true (B) false,A,"What evidence do scientists have that large quantities of oxygen entered the atmosphere? The iron contained in the rocks combined with the oxygen to form reddish iron oxides. By the beginning of the Proterozoic, banded-iron formations (BIFs) were forming. Banded-iron formations display alternating bands of iron oxide and iron-poor chert that probably represent a seasonal cycle of an aerobic and an anaerobic environment. The oldest BIFs are 3.7 billion years old, but they are very common during the Great Oxygenation Event 2.4 billion years ago (Figure 1.2). By 1.8 billion years ago, the amount of BIF declined. In recent times, the iron in these formations has been mined, and that explains the location of the auto industry in the upper Midwest. "
Some of the oxygen in Earths early atmosphere became ozone.,(A) true (B) false,A,"The second atmosphere, which was the first to stay with the planet, formed from volcanic outgassing and comet ices. This atmosphere had lots of water vapor, carbon dioxide, nitrogen, and methane but almost no oxygen. Why was there so little oxygen? Plants produce oxygen when they photosynthesize but life had not yet begun or had not yet developed photosynthesis. In the early atmosphere, oxygen only appeared when sunlight split water molecules into hydrogen and oxygen and the oxygen accumulated in the atmosphere. Without oxygen, life was restricted to tiny simple organisms. Why is oxygen essential for most life on Earth? 1. Oxygen is needed to make ozone, a molecule made of three oxygen ions, O3 . Ozone collects in the atmospheric ozone layer and blocks harmful ultraviolet radiation from the Sun. Without an ozone layer, life in the early Earth was almost impossible. 2. Animals need oxygen to breathe. No animals would have been able to breathe in Earths early atmosphere. "
The first photosynthetic organisms were most like modern E. coli.,(A) true (B) false,B,The first organisms to photosynthesize were cyanobacteria. These organisms may have been around as far back as 3.5 billion years and are still alive today (Figure 12.7). Now they are called blue-green algae. They are common in lakes and seas and account for 20% to 30% of photosynthesis today. 
There are no longer any prokaryotes living on Earth.,(A) true (B) false,B,"Prokaryotes were the first living things to evolve on Earth, probably around 3.8 billion years ago. They were the only living things until the first eukaryotic cells evolved about 2 billion years ago. Prokaryotes are still the most numerous organisms on Earth. Its not certain how the three domains of life are related. Archaea were once thought to be offshoots of Bacteria that were adapted to extreme environments. For their part, Bacteria were considered to be ancestors of Eukarya. Scientists now know that Archaea share several traits with Eukarya that Bacteria do not share. How can this be explained? One hypothesis is that the first Eukarya formed when an archaean cell fused with a bacterial cell. By fusing, the two prokaryotic cells became the nucleus and cytoplasm of a new eukaryotic cell. If this hypothesis is correct, both prokaryotic domains are ancestors of Eukarya. "
Ediacara fauna evolved toward the end of the Precambrian Era.,(A) true (B) false,A,"For life to become even more complex, multicellular organisms needed to evolve. Prokaryotes and eukaryotes can be multicellular. Toward the end of the Precambrian, the Ediacara Fauna evolved (Figure 12.8). These are the fossils discovered by Walcott in the introduction to the next section. The Ediacara was extremely diverse. They appeared after Earth defrosted from a worldwide glaciation. The Ediacara fauna seem to have died out. Other multicellular organisms appeared in the Phanerozoic. "
first organisms to make food by photosynthesis,(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,E,The first organisms to photosynthesize were cyanobacteria. These organisms may have been around as far back as 3.5 billion years and are still alive today (Figure 12.7). Now they are called blue-green algae. They are common in lakes and seas and account for 20% to 30% of photosynthesis today. 
type of organism that contains a nucleus in its cell(s),(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,C,Eukaryotic cells contain a nucleus and several other types of organelles. These structures carry out many vital cell functions. 
process that added oxygen to Earths early atmosphere,(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,G,"When photosynthesis evolved and spread around the planet, oxygen was released in abundance. The addition of oxygen is what created Earths third atmosphere. This event, which occurred about 2.5 billion years ago, is sometimes called the oxygen catastrophe because so many organisms died. Although entire species died out and went extinct, this event is also called the Great Oxygenation Event because it was a great opportunity. The organisms that survived developed a use for oxygen through cellular respiration, the process by which cells can obtain energy from organic molecules. This opened up many opportunities for organisms to evolve to fill different niches and many new types of organisms first appeared on Earth. "
gas that protects Earth from harmful radiation,(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,F,"Gases in the atmosphere surround Earth like a blanket. They keep the temperature in a range that can support life. The gases keep out some of the Suns scorching heat during the day. At night, they hold the heat close to the surface, so it doesnt radiate out into space. "
type of organism that lacks a nucleus in its cell(s),(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,D,"Prokaryotic cells are cells that lack a nucleus. The DNA in prokaryotic cells is in the cytoplasm, rather than enclosed within a nuclear membrane. All the organisms in the Bacteria and Archaea Domains have prokaryotic cells. No other organisms have this type of cell. Organisms with prokaryotic cells are called prokaryotes. They are all single-celled organisms. They were the first type of organisms to evolve. They are still the most numerous organisms today. You can see a model of a prokaryotic cell in Figure 3.3. The cell in the figure is a bacterium. Notice how it contains a cell membrane, cytoplasm, ribosomes, and several other structures. However, the cell lacks a nucleus. The cells DNA is circular. It coils up in a mass called a nucleoid that floats in the cytoplasm. "
organic compound that stores genetic information,(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,A,"Living cells need organic molecules, known as nucleic acids, to store genetic information and pass it to the next generation. Deoxyribonucleic acid (DNA) is the nucleic acid that carries information for nearly all living cells today and did for most of Earths history. Ribonucleic acid (RNA) delivers genetic instructions to the location in a cell where protein is synthesized. "
waste product of photosynthesis,(A) nucleic acid (B) oxygen (C) eukaryote (D) prokaryote (E) cyanobacteria (F) ozone (G) photosynthesis,B,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
About what percent of Earths surface is covered with water?,(A) 20 percent (B) 50 percent (C) 70 percent (D) 90 percent,C,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
Water is stored in,(A) ice and snow (B) the atmosphere (C) lakes and streams (D) all of these,D,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
What percent of Earths total water is fresh water?,(A) 3 percent (B) 52 percent (C) 79 percent (D) 97 percent,A,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
The largest amount of fresh water is contained in,(A) ice caps (B) glaciers and inland seas (C) b rivers and streams (D) c the oceans (E) d groundwater and soil moisture,A,"Earths oceans contain 97% of the planets water. That leaves just 3% as fresh water, water with low concentrations of salts (Figure 1.1). Most fresh water is trapped as ice in the vast glaciers and ice sheets of Greenland and Antarctica. How is the 3% of fresh water divided into different reservoirs? How much of that water is useful for living creatures? How much for people? A storage location for water such as an ocean, glacier, pond, or even the atmosphere is known as a reservoir. A water molecule may pass through a reservoir very quickly or may remain for much longer. The amount of time a molecule stays in a reservoir is known as its residence time. The distribution of Earths water. Click image to the left or use the URL below. URL: "
Most of Earths liquid fresh water is located in,(A) underground rocks (B) living organisms (C) surface soil (D) large lakes,A,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
The water cycle,(A) begins and ends in the oceans (B) has no beginning and has no end (C) begins in the oceans and ends in groundwater aquifers (D) begins in the atmosphere and ends in the oceans,B,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
The energy for the water cycle comes from,(A) radioactive decay (B) Earths internal heat (C) the Sun (D) water when it changes state,C,"The Sun, many millions of kilometers away, provides the energy that drives the water cycle. Our nearest star directly impacts the water cycle by supplying the energy needed for evaporation. "
Most fresh water enters the atmosphere when water evaporates from,(A) oceans (B) plants (C) lakes (D) soils,A,"Water changes from a liquid to a gas by evaporation to become water vapor. The Suns energy can evaporate water from the ocean surface or from lakes, streams, or puddles on land. Only the water molecules evaporate; the salts remain in the ocean or a fresh water reservoir. The water vapor remains in the atmosphere until it undergoes condensation to become tiny droplets of liquid. The droplets gather in clouds, which are blown about the globe by wind. As the water droplets in the clouds collide and grow, they fall from the sky as precipitation. Precipitation can be rain, sleet, hail, or snow. Sometimes precipitation falls back into the ocean and sometimes it falls onto the land surface. "
Clouds form when water vapor,(A) evaporates (B) condenses (C) transpires (D) freezes,B,"Clouds form when water vapor condenses around particles in the air. The particles are specks of matter, such as dust or smoke. Billions of these tiny water droplets come together to make up a cloud. If the air is very cold, ice crystals form instead of liquid water. "
"In infiltration, water goes",(A) through the ground (B) to the atmosphere by changing from liquid to gas (C) to the atmosphere through a plant (D) none of these,A,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
Forms of precipitation include,(A) rain (B) snow (C) sleet (D) all of the above,D,"The most common precipitation comes from clouds. Rain or snow droplets grow as they ride air currents in a cloud and collect other droplets (Figure 1.2). They fall when they become heavy enough to escape from the rising air currents that hold them up in the cloud. One million cloud droplets will combine to make only one rain drop! If temperatures are cold, the droplet will hit the ground as snow. (a) Dew on a flower. (b) Hoar frost. (a) Rain falls from clouds when the temperature is fairly warm. (b) Snow storm in Helsinki, Finland. Other less common types of precipitation are sleet (Figure 1.3). Sleet is rain that becomes ice as it hits a layer of freezing air near the ground. If a frigid raindrop freezes on the frigid ground, it forms glaze. Hail forms in cumulonimbus clouds with strong updrafts. An ice particle travels until it finally becomes too heavy and it drops. (a) Sleet. (b) Glaze. (c) Hail. This large hail stone is about 6 cm (2.5 inches) in diameter. Click image to the left or use the URL below. URL: "
Water vapor enters the atmosphere through,(A) infiltration (B) transpiration (C) condensation (D) two of the above,B,"Figure 15.2 shows the role of the atmosphere in the water cycle. Water vapor rises from Earths surface into the atmosphere. As it rises, it cools. The water vapor may then condense into water droplets and form clouds. If enough water droplets collect in clouds they may fall as rain. This how freshwater gets from the atmosphere back to Earths surface. "
Icebergs are made of frozen salt water.,(A) true (B) false,B,"You dont have to be an ice climber to enjoy ice. Skating and fishing are two other sports that are also done on ice. What is ice? Its simply water in the solid state. The process in which water or any other liquid changes to a solid is called freezing. Freezing occurs when a liquid cools to a point at which its particles no longer have enough energy to overcome the force of attraction between them. Instead, the particles remain in fixed positions, crowded closely together, as shown in the Figure 1.1. "
Almost 80 percent of Earths fresh water is frozen.,(A) true (B) false,A,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
There is more water in Earths living things than there is in the atmosphere.,(A) true (B) false,B,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
Soil moisture is important for plants to grow.,(A) true (B) false,A,A significant amount of water infiltrates into the ground. Soil moisture is an important reservoir for water (Figure The moisture content of soil in the United States varies greatly. 
Some water molecules may be billions of years old.,(A) true (B) false,A,"Did you ever wonder where the water in your glass came from or where its been? The next time you take a drink of water, think about this. Each water molecule has probably been around for billions of years. Thats because Earths water is constantly recycled. "
Water exists on Earth in all three states of matter.,(A) true (B) false,A,"Water is the only substance on Earth that is present in all three states of matter - as a solid, liquid or gas. (And Earth is the only planet where water is abundantly present in all three states.) Because of the ranges in temperature in specific locations around the planet, all three phases may be present in a single location or in a region. The three phases are solid (ice or snow), liquid (water), and gas (water vapor). See ice, water, and clouds (Figure 1.2). (a) Ice floating in the sea. Can you find all three phases of water in this image? (b) Liquid water. (c) Water vapor is invisible, but clouds that form when water vapor condenses are not. Click image to the left or use the URL below. URL: "
The water cycle has no beginning or end.,(A) true (B) false,A,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
Water can go through the water cycle without changing state.,(A) true (B) false,B,"Water keeps changing state as it goes through the water cycle. This means that it can be a solid, liquid, or gas. How does water change state? How does it keep moving through the cycle? As Figure 13.3 shows, several processes are involved. Evaporation changes liquid water to water vapor. Energy from the Sun causes water to evaporate. Most evaporation is from the oceans because they cover so much area. The water vapor rises into the atmosphere. Transpiration is like evaporation because it changes liquid water to water vapor. In transpiration, plants release water vapor through their leaves. This water vapor rises into the atmosphere. Condensation changes water vapor to liquid water. As air rises higher into the atmosphere, it cools. Cool air can hold less water vapor than warm air. So some of the water vapor condenses into water droplets. Water droplets may form clouds. Precipitation is water that falls from clouds to Earths surface. Water droplets in clouds fall to Earth when they become too large to stay aloft. The water falls as rain if the air is warm. If the air is cold, the water may freeze and fall as snow, sleet, or hail. Most precipitation falls into the oceans. Some falls on land. Runoff is precipitation that flows over the surface of the land. This water may travel to a river, lake, or ocean. Runoff may pick up fertilizer and other pollutants and deliver them to the water body where it ends up. In this way, runoff may pollute bodies of water. Infiltration is the process by which water soaks into the ground. Some of the water may seep deep under- ground. Some may stay in the soil, where plants can absorb it with their roots. In all these ways, water keeps cycling. The water cycle repeats over and over again. Who knows? Maybe a water molecule that you drink today once quenched the thirst of a dinosaur. "
Water turns to gas through condensation.,(A) true (B) false,B,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
Most condensation of water takes place in the oceans.,(A) true (B) false,B,"The oceans are an essential part of Earths water cycle. Since they cover so much of the planet, most evaporation comes from oceans and most precipitation falls on oceans. "
The atoms that make up water molecules come together and break apart easily.,(A) true (B) false,B,"Water is an amazing molecule. It has a very simple chemical formula, H2 O. It is made of just two hydrogen atoms bonded to one oxygen atom. Water is remarkable in terms of all the things it can do. Lots of things dissolve easily in water. Some types of rock can even completely dissolve in water! Other minerals change by adding water into their structure. "
Cold air can hold less water than warm air so when air cools water may condense.,(A) true (B) false,A,"When air is very humid, it doesnt have to cool very much for water vapor in the air to start condensing. The temperature at which condensation occurs is called the dew point. The dew point varies depending on air temperature and moisture content. It is always less than or equal to the actual air temperature, but warmer air and moister air have dew points closer to the actual air temperature. Thats why glasses of cold drinks sweat more on a hot, humid day than they do on a cool, dry day. Q: What happens when air temperature reaches the dew point? A: When air temperature reaches the dew point, water vapor starts condensing. It may form dew (as on the spider web in the opening image), clouds, or fog. Dew forms on solid objects on the ground. Clouds form on tiny particles in the air high above the ground. Fog is a cloud that forms on tiny particles in the air close to the ground. "
Water that forms clouds always falls to the ground as precipitation.,(A) true (B) false,B,"Clouds are needed for precipitation. This may fall as liquid water, or it may fall as frozen water, such as snow. "
"Runoff may pollute rivers, lakes, and oceans.",(A) true (B) false,A,"Runoff from crops, livestock, and poultry farming carries contaminants such as fertilizers, pesticides, and animal waste into nearby waterways (Figure 1.3). Soil and silt also run off farms. Animal wastes may carry harmful diseases, particularly in the developing world. The high density of animals in a factory farm means that runoff from the area is full of pollutants. Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. "
Most of Earths precipitation falls on land.,(A) true (B) false,B,"Most precipitation that occurs over land, however, is not absorbed by the soil and is called runoff. This runoff collects in streams and rivers and eventually flows back into the ocean. "
water that falls from clouds to Earths surface,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,F,"Water changes from a liquid to a gas by evaporation to become water vapor. The Suns energy can evaporate water from the ocean surface or from lakes, streams, or puddles on land. Only the water molecules evaporate; the salts remain in the ocean or a fresh water reservoir. The water vapor remains in the atmosphere until it undergoes condensation to become tiny droplets of liquid. The droplets gather in clouds, which are blown about the globe by wind. As the water droplets in the clouds collide and grow, they fall from the sky as precipitation. Precipitation can be rain, sleet, hail, or snow. Sometimes precipitation falls back into the ocean and sometimes it falls onto the land surface. "
"continuous movement of water through the oceans, atmosphere, land, and living things",(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,D,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
process in which plants release water vapor through their leaves,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,E,"Plants and animals depend on water to live. They also play a role in the water cycle. Plants take up water from the soil and release large amounts of water vapor into the air through their leaves (Figure 1.3), a process known as transpiration. "
precipitation that flows over the surface of the ground,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,G,"Most precipitation that occurs over land, however, is not absorbed by the soil and is called runoff. This runoff collects in streams and rivers and eventually flows back into the ocean. "
process in which water vapor changes to liquid water,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,A,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
process in which liquid water changes to water vapor,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,B,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
process in which water soaks into the ground,(A) condensation (B) evaporation (C) infiltration (D) water cycle (E) transpiration (F) precipitation (G) runoff,C,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
Possible sources of water in a lake include,(A) rivers (B) runoff (C) precipitation (D) all of the above,D,Ponds and lakes may get their water from several sources. Some falls directly into them as precipitation. Some enters as runoff and some from streams and rivers. Water leaves ponds and lakes through evaporation and also as outflow. 
The Great Lakes,(A) contain 12% of the worlds fresh surface water (B) are the worlds largest freshwater lakes (C) are so cold (D) not much lives in them (E) d formed when tectonic faults created basins,B,"In winter, a continental polar air mass travels down from Canada. As the frigid air travels across one of the Great Lakes, it warms and absorbs moisture. When the air mass reaches the leeward side of the lake, it is very unstable and it drops tremendous amounts of snow. This lake-effect snow falls on the snowiest metropolitan areas in the United States: Buffalo and Rochester, New York (Figure 1.3). Click image to the left or use the URL below. URL:  Frigid air travels across the Great Lakes and dumps lake-effect snow on the lee- ward side. "
Rift lakes form because of,(A) glaciers (B) volcanoes (C) plate tectonics (D) none of the above,C,"The depression that allows water to collect to form a lake may come about in a variety of ways. The Great Lakes, for example, are glacial lakes. A glacial lake forms when a glacier scrapes a large hole in the ground. When the glacier melts, the water fills the hole and forms a lake. Over time, water enters the lake from the sources mentioned above as well. Other lakes are crater lakes or rift lakes, which are pictured in Figure 13.8. Crater lakes form when volcanic eruptions create craters that fill with water. Rift lakes form when movements of tectonic plates create low places that fill with water. "
Lakes,(A) are often the result of glaciation (B) are permanent features of a landscape (C) all become salty over time (D) none of these,A,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
Wetlands that have trees include,(A) marshes (B) swamps (C) bogs (D) two of the above,B,"Not all wetlands are alike, as you can see from Figure 13.9. Wetlands vary in how wet they are and how much of the year they are soaked. Wetlands also vary in the kinds of plants that live in them. This depends mostly on the climate where the wetland is found. Types of wetlands include marshes, swamps, and bogs. A marsh is a wetland that is usually under water. It has grassy plants, such as cattails. A swamp is a wetland that may or may not be covered with water but is always soggy. It has shrubs or trees. A bog is a wetland that has soggy soil. It is generally covered with mosses. "
A stream is,(A) any water that flows downhill (B) a large amount of water that flows downhill (C) any water that flows downhill in a channel (D) any water in a channel or depression,C,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
A broad curve in a river is a,(A) tributary (B) delta (C) floodplain (D) meander,D,"Rivers flowing over gentle slopes erode the sides of their channels more than the bottom. Large curves, called meanders, form because of erosion and deposition by the moving water. The curves are called meanders because they slowly wander over the land. You can see how this happens in Figure 10.6. As meanders erode from side to side, they create a floodplain. This is a broad, flat area on both sides of a river. Eventually, a meander may become cut off from the rest of the river. This forms an oxbow lake, like the one in Figure 10.6. "
A bog is generally covered with,(A) grasses (B) cattails (C) mosses (D) shrubs,C,"Not all wetlands are alike, as you can see from Figure 13.9. Wetlands vary in how wet they are and how much of the year they are soaked. Wetlands also vary in the kinds of plants that live in them. This depends mostly on the climate where the wetland is found. Types of wetlands include marshes, swamps, and bogs. A marsh is a wetland that is usually under water. It has grassy plants, such as cattails. A swamp is a wetland that may or may not be covered with water but is always soggy. It has shrubs or trees. A bog is a wetland that has soggy soil. It is generally covered with mosses. "
Why are wetlands useful?,(A) They speed up runoff (B) They reduce the risk of floods (C) They are good places for golf courses (D) two of the above,B,"People used to think that wetlands were useless. Many wetlands were filled in with rocks and soil to create lands that were then developed with roads, golf courses, and buildings. Now we know that wetlands are very important. Laws have been passed to help protect them. Why are wetlands so important? Wetlands have great biodiversity. They provide homes or breeding sites to a huge variety of species. Because so much wetland area has been lost, many of these species are endangered. Wetlands purify water. They filter sediments and toxins from runoff before it enters rivers, lakes, and oceans. Wetlands slow rushing water. During hurricanes and other extreme weather, wetlands reduce the risk of floods. Although the rate has slowed, wetlands are still being destroyed today. "
Two water droplets fall on opposite sides of a divide. Those droplets will,(A) eventually end up in the same ocean (B) eventually end up in two different oceans (C) rapidly end up in the same river (D) none of these,B,"Millions of water molecules in a cloud must condense to make a single raindrop or snowflake. The drop or flake falls when it becomes too heavy for updrafts to keep it aloft. As a drop or flake falls, it may collect more water and get larger. "
A small stream that flows into a bigger stream is called a,(A) river (B) meander (C) tributary (D) river system,C,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
"When a river reaches its mouth, it may drop its sediment and form a",(A) divide (B) delta (C) basin (D) bog,B,"When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. "
A brook is a type of wetland.,(A) true (B) false,B,"Not all wetlands are alike, as you can see from Figure 13.9. Wetlands vary in how wet they are and how much of the year they are soaked. Wetlands also vary in the kinds of plants that live in them. This depends mostly on the climate where the wetland is found. Types of wetlands include marshes, swamps, and bogs. A marsh is a wetland that is usually under water. It has grassy plants, such as cattails. A swamp is a wetland that may or may not be covered with water but is always soggy. It has shrubs or trees. A bog is a wetland that has soggy soil. It is generally covered with mosses. "
A stream always flows from a higher to a lower elevation.,(A) true (B) false,A,"As a stream flows from higher elevations, like in the mountains, towards lower elevations, like the ocean, the work of the stream changes. At a streams headwaters, often high in the mountains, gradients are steep (Figure 1.3). The stream moves fast and does lots of work eroding the stream bed. Headwaters of the Roaring Fork River in Colorado. As a stream moves into lower areas, the gradient is not as steep. Now the stream does more work eroding the edges of its banks. Many streams develop curves in their channels called meanders (Figure 1.4). As the river moves onto flatter ground, the stream erodes the outer edges of its banks to carve a floodplain, which is a flat, level area surrounding the stream channel (Figure 1.5). Base level is where a stream meets a large body of standing water, usually the ocean, but sometimes a lake or pond. Streams work to down cut in their stream beds until they reach base level. The higher the elevation, the farther the stream is from where it will reach base level and the more cutting it has to do. The ultimate base level is sea level. "
The bottom of a river channel is called the bank.,(A) true (B) false,B,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
Streams usually begin with water from snow melt and possibly springs.,(A) true (B) false,A,"When water falls from the sky as rain it may enter streams and rivers that flow downward to oceans and lakes. Water that falls as snow may sit on a mountain for several months. Snow may become part of the ice in a glacier, where it may remain for hundreds or thousands of years. Snow and ice may go directly back into the air by sublimation, the process in which a solid changes directly into a gas without first becoming a liquid. Although you probably have not seen water vapor undergoing sublimation from a glacier, you may have seen dry ice sublimate in air. Snow and ice slowly melt over time to become liquid water, which provides a steady flow of fresh water to streams, rivers, and lakes below. A water droplet falling as rain could also become part of a stream or a lake. At the surface, the water may eventually evaporate and reenter the atmosphere. "
A single stream always has just one source.,(A) true (B) false,B,"All streams and rivers have several features in common. These features are shown in (Figure 13.5). The place where a stream or river starts is its source. The source might be a spring, where water flows out of the ground. Or the source might be water from melting snow on a mountain top. A single stream may have multiple sources. A stream or river probably ends when it flows into a body of water, such as a lake or an ocean. A stream ends at its mouth. As the water flows into the body of water, it slows down and drops the sediment it was carrying. The sediment may build up to form a delta. Several other features of streams and rivers are also shown in Figure 13.5. Small streams often flow into bigger streams or rivers. The small streams are called tributaries. A river and all its tributaries make up a river system. At certain times of year, a stream or river may overflow its banks. The area of land that is flooded is called the floodplain. The floodplain may be very wide where the river flows over a nearly flat surface. A river flowing over a floodplain may wear away broad curves. These curves are called meanders. "
A single stream will have a single water source.,(A) true (B) false,B,"Groundwater meets the surface in a stream (Figure 1.2) or a spring (Figure 1.3). A spring may be constant, or may only flow at certain times of year. Towns in many locations depend on water from springs. Springs can be an extremely important source of water in locations where surface water is scarce. "
Moving water slows down when it enters a body of still water.,(A) true (B) false,A,"Flowing water slows down when it reaches flatter land or flows into a body of still water. What do you think happens then? The water starts dropping the particles it was carrying. As the water slows, it drops the largest particles first. The smallest particles settle out last. "
A rivers basin is also called its bed.,(A) true (B) false,B,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
The Great Lakes are in basins carved by glaciers.,(A) true (B) false,A,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
A divide is the lowest point between two river basins.,(A) true (B) false,B,"A divide is a topographically high area that separates a landscape into different water basins (Figure 1.6). Rain that falls on the north side of a ridge flows into the northern drainage basin and rain that falls on the south side flows into the southern drainage basin. On a much grander scale, entire continents have divides, known as continental divides. A green floodplain surrounds the Red Rock River as it flows through Montana. (a) The divides of North America. In the Rocky Mountains in Colorado, where does a raindrop falling on the western slope end up? How about on the eastern slope? (b) At Triple Divide Peak in Montana water may flow to the Pacific, the Atlantic, or Hudson Bay depending on where it falls. Can you locate where in the map of North America this peak sits? "
A stream is a small river.,(A) true (B) false,B,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
A floodplain may be very wide and flat.,(A) true (B) false,A,"Although archaea are known for living in unusual environments, such as the Dead Sea, inside hot springs, and in the guts of cows, they also live in more common environments. For example, new research shows that archaea are abundant in the soil. They also live among the plankton in the ocean ( Figure 1.3). Therefore, scientists are just beginning to discover some of the important roles that archaea have in the environment. Thermococcus gammatolerans are another type of archaea. "
All lakes have fresh water.,(A) true (B) false,B,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
Sunlight may not be able to reach the bottom of a deep lake.,(A) true (B) false,A,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
The Great Lakes are volcanic lakes.,(A) true (B) false,B,"The depression that allows water to collect to form a lake may come about in a variety of ways. The Great Lakes, for example, are glacial lakes. A glacial lake forms when a glacier scrapes a large hole in the ground. When the glacier melts, the water fills the hole and forms a lake. Over time, water enters the lake from the sources mentioned above as well. Other lakes are crater lakes or rift lakes, which are pictured in Figure 13.8. Crater lakes form when volcanic eruptions create craters that fill with water. Rift lakes form when movements of tectonic plates create low places that fill with water. "
small body of standing water,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,C,"Ponds are small bodies of fresh water that usually have no outlet; ponds are often are fed by underground springs. Like lakes, ponds are bordered by hills or low rises so the water is blocked from flowing directly downhill. "
event in which a body of water overflows its banks,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,A,"A flood occurs when so much water enters a stream or river that it overflows its banks. Flood waters from a river are shown in Figure 13.10. Like this flood, many floods are caused by very heavy rains. Floods may also occur when deep snow melts quickly in the spring. Floods are a natural part of the water cycle, but they can cause a lot of damage. Farms and homes may be lost, and people may die. In 1939, millions of people died in a flood in China. Although freshwater is needed to grow crops and just to live, too much freshwater in the same place at once can be deadly. "
area that is covered with water or has soggy soil during all or part of the year,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,F,"Some of Earths freshwater is found in wetlands. A wetland is an area that is covered with water, or at least has very soggy soil, during all or part of the year. Certain species of plants thrive in wetlands, and they are rich ecosystems. Freshwater wetlands are usually found at the edges of steams, rivers, ponds, or lakes. Wetlands can also be found at the edges of seas. "
any body of fresh water that flows downhill in a channel,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,E,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
large body of fresh water that flows downhill in a channel,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,D,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
large body of standing water,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,B,"After a heavy rain, you may find puddles of water standing in low spots. The same principle explains why water collects in ponds and lakes. Water travels downhill, so a depression in the ground fills with standing water. A pond is a small body of standing water. A lake is a large body of standing water. Most lakes have freshwater, but a few are salty. The Great Salt Lake in Utah is an example of a saltwater lake. The water in a large lake may be so deep that sunlight cannot penetrate all the way to the bottom. Without sunlight, water plants and algae cannot live on the bottom of the lake. Thats because plants need sunlight for photosynthesis. The largest lakes in the world are the Great Lakes. They lie between the U.S. and Canada, as shown in Figure 13.7. How great are they? They hold 22 percent of all the worlds fresh surface water! "
all of the land drained by a river system,(A) flood (B) lake (C) pond (D) river (E) stream (F) wetland (G) watershed,G,"All of the land drained by a river system is called its basin, or watershed. One river systems basin is separated from another river systems basin by a divide. The divide is created by the highest points between the two river basins. Precipitation that falls within a river basin always flows toward that river. Precipitation that falls on the other side of the divide flows toward a different river. Figure 13.6 shows the major river basins in the U.S. You can watch an animation of water flowing through a river basin at this link: http://trashfree.org/btw/graphics/watershed_anim.gif "
Groundwater usually,(A) flows rapidly like an underground river (B) flows uphill or downhill depending on the topography (C) flows very slowly between grains of sediment (D) is stationary in an aquifer,C,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
What are the two features of a good aquifer?,(A) high porosity and high permeability (B) low porosity and high permeability (C) high porosity and low permeability (D) low porosity and low permeability,A,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
"During very wet times, the water table will",(A) stay the same (B) rise (C) fall (D) hard to know; water tables are not affected by surface conditions,B,"The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. "
Water replenishes an aquifer from,(A) glacial meltwater (B) rainfall (C) snow melt (D) all of these,D,"Water may seep through dirt and rock below the soil and then through pores infiltrating the ground to go into Earths groundwater system. Groundwater enters aquifers that may store fresh water for centuries. Alternatively, the water may come to the surface through springs or find its way back to the oceans. "
Geysers erupt because,(A) pressure builds until the water breaks through (B) they have much more water than hot springs (C) the water needs to get downhill in a hurry (D) they are above a volcano that is about to erupt,A,"Geysers are also created by water that is heated beneath the Earths surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser. There are only a few areas in the world where the conditions are right for the formation of geysers. Only about 1,000 geysers exist worldwide. About half of them are in the United States. The most famous geyser is Old Faithful at Yellowstone National Park (Figure 8.23). It is rare for a geyser to erupt so regularly, which is why Old Faithful is famous. "
The water table in an area may rise or fall.,(A) true (B) false,A,Lowering the water table may cause the ground surface to sink. Subsidence may occur beneath houses and other structures (Figure 1.4). 
An aquifer usually forms in a layer of clay.,(A) true (B) false,B,"An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge. "
The rock layer below an aquifer always consists of permeable rock.,(A) true (B) false,B,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
Water in hot springs is heated by hot magma.,(A) true (B) false,A,"Water works its way through porous rocks or soil. Sometimes this water is heated by nearby magma. If the water makes its way to the surface, it forms a hot spring or a geyser. "
Very few land areas have aquifers beneath them.,(A) true (B) false,B,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
Aquifers are generally found at the same depths.,(A) true (B) false,B,"Groundwater resides in aquifers, porous rock and sediment with water in between. Water is attracted to the soil particles, and capillary action, which describes how water moves through porous media, moves water from wet soil to dry areas. Aquifers are found at different depths. Some are just below the surface and some are found much deeper below the land surface. A region may have more than one aquifer beneath it and even most deserts are above aquifers. The source region for an aquifer beneath a desert is likely to be far away, perhaps in a mountainous area. "
It is impossible for an aquifer to ever run dry.,(A) true (B) false,B,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
The Ogallala aquifer is one of the biggest aquifers in the world.,(A) true (B) false,A,"One of the biggest aquifers in the world is the Ogallala aquifer. As you can see from Figure 13.13, this aquifer lies beneath parts of eight U.S. states. It covers a total area of 451,000 square kilometers (174,000 square miles). In some places, it is less than a meter deep. In other places, it is hundreds of meters deep. The Ogallala aquifer is an important source of freshwater in the American Midwest. This is a major farming area, and much of the water is used to irrigate crops. The water in this aquifer is being used up ten times faster than it is recharged. If this continues, what might happen to the Ogallala aquifer? "
Land use in an area can affect the amount of water that is available to enter groundwater.,(A) true (B) false,A,"The amount of water that is available to enter groundwater in a region, called recharge, is influenced by the local climate, the slope of the land, the type of rock found at the surface, the vegetation cover, land use in the area, and water retention, which is the amount of water that remains in the ground. More water goes into the ground where there is a lot of rain, flat land, porous rock, exposed soil, and where water is not already filling the soil and rock. "
Much of the water taken from the Ogallala aquifer is used to irrigate crops.,(A) true (B) false,A,"The Ogallala Aquifer supplies about one-third of the irrigation water in the United States. The Ogallala Aquifer is widely used by people for municipal and agricultural needs. (Figure 1.2). The aquifer is found from 30 to 100 meters deep over an area of about 440,000 square kilometers! The water in the aquifer is mostly from the last ice age. About eight times more water is taken from the Ogallala Aquifer each year than is replenished. Much of the water is used for irrigation (Figure 1.3). Click image to the left or use the URL below. URL:  Intense drought has reduced groundwater levels in the southern U.S., particularly in Texas and New Mexico. "
A good aquifer has rock in it that is porous and permeable.,(A) true (B) false,A,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
The bottom layer of an aquifer has impermeable rock.,(A) true (B) false,A,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
Many hot springs are also mineral springs.,(A) true (B) false,A,"Some springs have water that contains minerals. Groundwater dissolves minerals out of the rock as it seeps through the pores. The water in some springs is hot because it is heated by hot magma. Many hot springs are also mineral springs. Thats because hot water can dissolve more minerals than cold water. Grand Prismatic Spring, shown in Figure 13.16, is a hot mineral spring. Dissolved minerals give its water a bright blue color. The edge of the spring is covered with thick orange mats of bacteria. The bacteria use the minerals in the hot water to make food. "
The water table keeps water in an aquifer from seeping deeper underground.,(A) true (B) false,B,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
Water flows out of a well due to gravity.,(A) true (B) false,B,"Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water thats stored in an aquifer people must go after it. How? They dig a well. A well is a hole that is dug or drilled through the ground down to an aquifer. This is illustrated in Figure 13.18. People have depended on water from wells for thousands of years. To bring water to the surface takes energy because the force of gravity must be overcome. Today, many wells use electricity to pump water to the surface. However, in some places, water is still brought to the surface the old-fashioned way  with human labor. The well pictured in Figure 13.19 is an example of this type of well. A hand-cranked pulley is used to lift the bucket of water to the surface. "
not having tiny holes that water can pass through,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,G,"Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock. Look at the diagram in Figure 13.11. It shows two layers of porous rock. The top layer is not saturated; it is not full of water. The next layer is saturated. The water in this layer has nowhere else to go. It cannot seep any deeper into the ground because the rock below it is impermeable. "
underground rock layer that is saturated with water,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,A,"An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge. "
having tiny holes that water can pass through,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,C,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
top of an underground rock layer that is saturated with water,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,D,"The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. "
hole dug or drilled into the ground to reach an aquifer,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,E,"Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water thats stored in an aquifer people must go after it. How? They dig a well. A well is a hole that is dug or drilled through the ground down to an aquifer. This is illustrated in Figure 13.18. People have depended on water from wells for thousands of years. To bring water to the surface takes energy because the force of gravity must be overcome. Today, many wells use electricity to pump water to the surface. However, in some places, water is still brought to the surface the old-fashioned way  with human labor. The well pictured in Figure 13.19 is an example of this type of well. A hand-cranked pulley is used to lift the bucket of water to the surface. "
fresh water below Earths surface,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,B,"Freshwater below Earths surface is called groundwater. The water infiltrates, or seeps down into, the ground from the surface. How does this happen? And where does the water go? "
water that enters an aquifer,(A) aquifer (B) groundwater (C) porous (D) water table (E) well (F) recharge (G) impermeable,F,"Water may seep through dirt and rock below the soil and then through pores infiltrating the ground to go into Earths groundwater system. Groundwater enters aquifers that may store fresh water for centuries. Alternatively, the water may come to the surface through springs or find its way back to the oceans. "
Water infiltrates the ground where rock is,(A) permeable (B) recharged (C) saturated (D) shallow,A,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
The water in an aquifer is more likely to be polluted if the aquifer,(A) is close to the surface (B) does not have a water table (C) lies below a layer of impermeable rock (D) is recharged as quickly as water is removed,A,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
The Ogallala aquifer is an important source of water in the American,(A) Southwest (B) Northeast (C) Southeast (D) Midwest,D,"The Ogallala Aquifer supplies about one-third of the irrigation water in the United States. The Ogallala Aquifer is widely used by people for municipal and agricultural needs. (Figure 1.2). The aquifer is found from 30 to 100 meters deep over an area of about 440,000 square kilometers! The water in the aquifer is mostly from the last ice age. About eight times more water is taken from the Ogallala Aquifer each year than is replenished. Much of the water is used for irrigation (Figure 1.3). Click image to the left or use the URL below. URL:  Intense drought has reduced groundwater levels in the southern U.S., particularly in Texas and New Mexico. "
Water in a spring comes from a,(A) river or stream (B) lake or pond (C) layer of rock (D) none of the above,C,"The top of an aquifer may be high enough in some places to meet the surface of the ground. This often happens on a slope. The water flows out of the ground and creates a spring. A spring may be just a tiny trickle, or it may be a big gush of water. One of the largest springs in the world is Big Spring in Missouri, seen in Figure 13.14. Water flowing out of the ground at a spring may flow downhill and enter a stream. Thats what happens to the water that flows out of Big Spring in Missouri. If the water from a spring cant flow downhill, it may spread out to form a pond or lake instead. Lake George in New York State, which is pictured in Figure 13.15, is a spring-fed lake. The lake basin was carved by a glacier. "
The majority of Earths liquid fresh water is found in,(A) rocks (B) lakes (C) rivers (D) springs,A,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
An aquifer is recharged by,(A) a well (B) surface water (C) the water table (D) a spring or geyser,B,"An underground layer of rock that is saturated with groundwater is called an aquifer. A diagram of an aquifer is shown in Figure 13.12. Aquifers are generally found in porous rock, such as sandstone. Water infiltrates the aquifer from the surface. The water that enters the aquifer is called recharge. "
Rock that holds as much water as possible is said to be,(A) recharged (B) saturated (C) impermeable (D) infiltrated,B,"The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. "
Sources of water vapor in Earths very early atmosphere included,(A) volcanic eruptions (B) precipitation (C) the oceans (D) the moon,A,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
What percent of the Earth is covered in salt water oceans?,(A) 82% (B) 71% (C) 65% (D) 49%,B,"Earth is often called the water planet. Figure 13.1 shows why. If astronauts see Earth from space, this is how it looks. Notice how blue the planet appears. Thats because oceans cover much of Earths surface. Water is also found in the clouds that rise above the planet. Most of Earths water is salt water in the oceans. As Figure 13.2 shows, only 3 percent of Earths water is fresh. Freshwater is water that contains little or no dissolved salt. Most freshwater is frozen in ice caps and glaciers. Glaciers cover the peaks of some tall mountains. For example, the Cascades Mountains in North America and the Alps Mountains in Europe are capped with ice. Ice caps cover vast areas of Antarctica and Greenland. Chunks of ice frequently break off ice caps. They form icebergs that float in the oceans. "
Gases the oceans exchange with the atmosphere include,(A) oxygen (B) carbon dioxide (C) water vapor (D) all of the above,D,"Oceans are the major source of water vapor in the atmosphere. Sunlight heats water near the sea surface, as shown in Figure 14.3. As the water warms, some of it evaporates. The water vapor rises into the air, where it may form clouds and precipitation. Precipitation provides the freshwater needed by plants and other living things. Ocean water also absorbs gases from the atmosphere. The most important are oxygen and carbon dioxide. Oxygen is needed by living things in the oceans. Much of the carbon dioxide sinks to the bottom of the seas. Carbon dioxide is a major cause of global warming. By absorbing carbon dioxide, the oceans help control global warming. "
Coastal areas have a milder climate than inland areas because,(A) water does not change temperature as rapidly as land (B) currents move warm and cold water around (C) breezes blow between land and sea (D) all of these,D,"Coastal areas have a milder climate than inland areas. They are warmer in the winter and cooler in the summer. Thats because land near an ocean is influenced by the temperature of the oceans. The temperature of ocean water is moderate and stable. Why? There are two major reasons: 1. Water is much slower to warm up and cool down than land. As a result, oceans never get as hot or as cold as land. 2. Water flows through all the worlds oceans. Warm water from the equator mixes with cold water from the poles. The mixing of warm and cold water makes the water temperature moderate. Even inland temperatures are milder because of oceans. Without oceans, there would be much bigger temperature swings all over Earth. Temperatures might plunge hundreds of degrees below freezing in the winter. In the summer, lakes and seas might boil! Life as we know it could not exist on Earth without the oceans. "
Ocean water everywhere has a relatively moderate temperature because,(A) water flows throughout all the worlds oceans (B) water warms up and cools down more quickly than land (C) landmasses protect the oceans from temperature changes (D) all of the above,A,"Coastal areas have a milder climate than inland areas. They are warmer in the winter and cooler in the summer. Thats because land near an ocean is influenced by the temperature of the oceans. The temperature of ocean water is moderate and stable. Why? There are two major reasons: 1. Water is much slower to warm up and cool down than land. As a result, oceans never get as hot or as cold as land. 2. Water flows through all the worlds oceans. Warm water from the equator mixes with cold water from the poles. The mixing of warm and cold water makes the water temperature moderate. Even inland temperatures are milder because of oceans. Without oceans, there would be much bigger temperature swings all over Earth. Temperatures might plunge hundreds of degrees below freezing in the winter. In the summer, lakes and seas might boil! Life as we know it could not exist on Earth without the oceans. "
"Compared with shallow water, deeper water is",(A) saltier and colder (B) saltier and warmer (C) less salty and colder (D) less salty and warmer,A,"Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. Thats because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone. Water also gets colder as you go deeper. The weight of the water pressing down from above increases as well. At great depths, life becomes very difficult. The pressure is so great that only specially adapted creatures can live there. "
Salt in the oceans comes from,(A) deep-sea hydrothermal vents (B) near shore salt deposits (C) river inflow (D) mid-ocean ridges,C,"Ocean water is salty because water dissolves minerals out of rocks. This happens whenever water flows over or through rocks. Much of this water and its minerals flow in rivers that end up in the oceans. Minerals dissolved in water form salts. When the water evaporates, it leaves the salts behind. As a result, ocean water is much saltier than other water on Earth. "
Some ocean zones are based on,(A) distance from the equator (B) depth of water (C) longitude (D) two of the above,B,Oceanographers divide the ocean into zones both vertically and horizontally. 
Which ocean zone receives a lot of sunlight and nutrients?,(A) oceanic zone (B) aphotic zone (C) neritic zone (D) benthic zone,C,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
"The ocean zone that is always covered by water, but is fairly shallow in depth is the",(A) intertidal zone (B) oceanic zone (C) photic zone (D) neritic zone,A,"The seabed is divided into the zones described above, but ocean itself is also divided horizontally by distance from the shore. Nearest to the shore lies the intertidal zone (also called the littoral zone), the region between the high and low tidal marks. The hallmark of the intertidal is change: water is in constant motion in the form of waves, tides, and currents. The land is sometimes under water and sometimes exposed. The neritic zone is from low tide mark and slopes gradually downward to the edge of the seaward side of the continental shelf. Some sunlight penetrates to the seabed here. The oceanic zone is the entire rest of the ocean from the bottom edge of the neritic zone, where sunlight does not reach the bottom. The sea bed and water column are subdivided further, as seen in the Figure 1.1. Click image to the left or use the URL below. URL: "
Earths present oceans include the,(A) Antarctic Ocean (B) Tethys Ocean (C) Indian Ocean (D) two of the above,D,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
Most nutrients enter ocean water from the,(A) land (B) ocean floor (C) aphotic zone (D) atmosphere,A,"In addition to sunlight, aquatic producers also need dissolved oxygen and nutrients. Water near the surface generally contains more dissolved oxygen than deeper water. Many nutrients enter the water from the land. Therefore, water nearer shore usually contains more dissolved nutrients than water farther from shore. "
The oceans influence Earths atmosphere.,(A) true (B) false,A,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
Fewer organisms live in the oceans than on the land.,(A) true (B) false,B,"The oceans provide a home to many living things. In fact, a greater number of organisms lives in the oceans than on land. Coral reefs, like the one in Figure 14.4, have more diversity of life forms than almost anywhere else on Earth. "
Early Earth was too cold for liquid water to exist.,(A) true (B) false,B,"When Earth formed 4.6 billion years ago, it would not have been called the water planet. There were no oceans then. In fact, there was no liquid water at all. Early Earth was too hot for liquid water to exist. Earths early years were spent as molten rock and metal. "
The Dead Sea is extremely saline due to high evaporation.,(A) true (B) false,A,"Where does the salt in seawater come from? As water moves through rock and soil on land it picks up ions. This is the flip side of weathering. Salts comprise about 3.5% of the mass of ocean water, but the salt content, or salinity, is different in different locations. What would the salinity be like in an estuary? Where seawater mixes with fresh water, salinity is lower than average. What would the salinity be like where there is lots of evaporation? Where there is lots of evaporation but little circulation of water, salinity can be much higher. The Dead Sea has 30% salinity  nearly nine times the average salinity of ocean water (Figure 1.2). Why do you think this water body is called the Dead Sea? In some areas, dense saltwater and less dense freshwater mix, and they form an immiscible layer, just like oil and water. One such place is a ""cenote"", or underground cave, very common in certain parts of Central America. Ocean water is composed of many sub- stances, many of them salts such as sodium, magnesium, and calcium chlo- ride. Because of the increased salinity, the wa- ter in the Dead Sea is very dense, it has such high salinity that people can easily float in it! "
Oceans cover more than 70 percent of Earths surface.,(A) true (B) false,A,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
Earths oceans have always had the same configuration.,(A) true (B) false,B,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
Coastal areas always have colder climates than inland areas.,(A) true (B) false,B,"Even places at the same latitude may have different climates if one is on a coast and one is inland. On the coast, the climate is influenced by warm moist air from the ocean. A coastal climate is usually mild. Summers arent too hot, and winters arent too cold. Precipitation can be high due to the moisture in the air. Farther inland, the climate is influenced by cold or hot air from the land. This air may be dry because it comes from over land. An inland climate is usually more extreme. Winters may be very cold, and summers may be very hot. Precipitation can be low. "
Ocean water is saltier than any other water on Earths surface.,(A) true (B) false,A,"Ocean water is salty because water dissolves minerals out of rocks. This happens whenever water flows over or through rocks. Much of this water and its minerals flow in rivers that end up in the oceans. Minerals dissolved in water form salts. When the water evaporates, it leaves the salts behind. As a result, ocean water is much saltier than other water on Earth. "
Most nutrients in the ocean are washed in from the land.,(A) true (B) false,A,"In addition to sunlight, aquatic producers also need dissolved oxygen and nutrients. Water near the surface generally contains more dissolved oxygen than deeper water. Many nutrients enter the water from the land. Therefore, water nearer shore usually contains more dissolved nutrients than water farther from shore. "
The amount of salt in ocean water is the same everywhere on Earth.,(A) true (B) false,B,"Have you ever gone swimming in the ocean? If you have, then you probably tasted the salts in the water. By mass, salts make up about 3.5 percent of ocean water. Figure 14.5 shows the most common minerals in ocean water. The main components are sodium and chloride. Together they form the salt known as sodium chloride. You may know the compound as table salt or the mineral halite. The amount of salts in ocean water varies from place to place. For example, near the mouth of a river, ocean water may be less salty. Thats because river water contains less salt than ocean water. Where the ocean is warm, the water may be more salty. Can you explain why? (Hint: More water evaporates when the water is warm.) "
"About 250 million years ago, there was one world ocean known as Pansea.",(A) true (B) false,B,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
The climate of inland areas is affected by oceans.,(A) true (B) false,A,"When a place is near an ocean, the water can have a big effect on the climate. "
The water may be very deep in the neritic zone.,(A) true (B) false,B,"Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. Thats because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone. Water also gets colder as you go deeper. The weight of the water pressing down from above increases as well. At great depths, life becomes very difficult. The pressure is so great that only specially adapted creatures can live there. "
Nutrients may be scarce in the oceanic zone.,(A) true (B) false,A,"In addition to the amount of salts, other conditions in ocean water vary from place to place. One is the amount of nutrients in the water. Another is the amount of sunlight that reaches the water. These conditions depend mainly on two factors: distance from shore and depth of water. Oceans are divided into zones based on these two factors. The ocean floor makes up another zone. Figure 14.6 shows all the ocean zones. "
Temperature and pressure increase as you go deeper below the oceans surface.,(A) true (B) false,B,"Pressure is the amount of force acting on a given area. As you go deeper in the ocean, the pressure exerted by the water increases steadily. Thats because there is more and more water pressing down on you from above. The Figure 1.1 shows how pressure changes with depth. For each additional meter below the surface, pressure increases by 10 kPa. At 30 meters below the surface, the pressure is double the pressure at the surface. At a depth greater than 500 meters, the pressure is too great for humans to withstand without special equipment to protect them. At nearly 11,000 meters below the surface, the pressure is tremendous. "
ocean zone that is closest to shore,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,C,"The seabed is divided into the zones described above, but ocean itself is also divided horizontally by distance from the shore. Nearest to the shore lies the intertidal zone (also called the littoral zone), the region between the high and low tidal marks. The hallmark of the intertidal is change: water is in constant motion in the form of waves, tides, and currents. The land is sometimes under water and sometimes exposed. The neritic zone is from low tide mark and slopes gradually downward to the edge of the seaward side of the continental shelf. Some sunlight penetrates to the seabed here. The oceanic zone is the entire rest of the ocean from the bottom edge of the neritic zone, where sunlight does not reach the bottom. The sea bed and water column are subdivided further, as seen in the Figure 1.1. Click image to the left or use the URL below. URL: "
dissolved gas in ocean water,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,G,"Ocean water normally dissolves some of the carbon dioxide in the atmosphere. The burning of fossil fuels has increased the amount of carbon dioxide in the atmosphere. As a result, ocean water is also dissolving more carbon dioxide. When carbon dioxide dissolves in water, it forms a weak acid. With higher levels of dissolved carbon dioxide in ocean water, the water becomes more acidic. This process is called ocean acidification. Ocean acidification can kill some aquatic organisms, including corals and shellfish. It may make it more difficult for other aquatic organisms to reproduce. Both effects of acidification interfere with marine food webs, threatening the survival of many aquatic organisms. "
open ocean beyond the continental shelf,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,E,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
ocean zone on the ocean floor,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,B,Oceanographers divide the ocean into zones both vertically and horizontally. 
ocean zone where sunlight does not reach,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,A,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
main salt in ocean water,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,F,"Have you ever gone swimming in the ocean? If you have, then you probably tasted the salts in the water. By mass, salts make up about 3.5 percent of ocean water. Figure 14.5 shows the most common minerals in ocean water. The main components are sodium and chloride. Together they form the salt known as sodium chloride. You may know the compound as table salt or the mineral halite. The amount of salts in ocean water varies from place to place. For example, near the mouth of a river, ocean water may be less salty. Thats because river water contains less salt than ocean water. Where the ocean is warm, the water may be more salty. Can you explain why? (Hint: More water evaporates when the water is warm.) "
ocean zone that lies over the continental shelf,(A) aphotic zone (B) benthic zone (C) intertidal zone (D) neritic zone (E) oceanic zone (F) sodium chloride (G) carbon dioxide,D,"The seabed is divided into the zones described above, but ocean itself is also divided horizontally by distance from the shore. Nearest to the shore lies the intertidal zone (also called the littoral zone), the region between the high and low tidal marks. The hallmark of the intertidal is change: water is in constant motion in the form of waves, tides, and currents. The land is sometimes under water and sometimes exposed. The neritic zone is from low tide mark and slopes gradually downward to the edge of the seaward side of the continental shelf. Some sunlight penetrates to the seabed here. The oceanic zone is the entire rest of the ocean from the bottom edge of the neritic zone, where sunlight does not reach the bottom. The sea bed and water column are subdivided further, as seen in the Figure 1.1. Click image to the left or use the URL below. URL: "
What is the primary cause of the tides?,(A) Earths rotation (B) The moons gravity (C) the Suns gravity (D) wind,B,"Figure 14.13 shows why tides occur. The main cause of tides is the pull of the Moons gravity on Earth. The pull is greatest on whatever is closest to the Moon. Although the gravity pulls the land, only the water can move. As a result: Water on the side of Earth facing the Moon is pulled hardest by the Moons gravity. This causes a bulge of water on that side of Earth. That bulge is a high tide. Earth itself is pulled harder by the Moons gravity than is the ocean on the side of Earth opposite the Moon. As a result, there is bulge of water on the opposite side of Earth. This creates another high tide. With water bulging on two sides of Earth, theres less water left in between. This creates low tides on the other two sides of the planet. "
Surface currents,(A) are caused by Coriolis effect (B) flow in a counterclockwise direction in the Northern Hemisphere (C) are caused by winds that may have blown far from the current (D) none of these,D,The surface currents described above are all large and unchanging. Local surface currents are also found along shorelines (Figure 1.3). Two are longshore currents and rip currents. Rip currents are potentially dangerous currents that carry large amounts of water offshore quickly. Each summer in the United States at least a few people die when they are caught in rip currents. Longshore currents move water and sediment parallel to the shore in the direction of the prevailing local winds. 
Where in the ocean is wave energy the greatest?,(A) at the surface (B) at the ocean floor (C) half way between the surface and the ocean floor (D) None of the above,A,"Ocean waves originate from wind blowing - steady winds or high storm winds - over the water. Sometimes these winds are far from where the ocean waves are seen. What factors create the largest ocean waves? The largest wind waves form when the wind is very strong blows steadily for a long time blows over a long distance The wind could be strong, but if it gusts for just a short time, large waves wont form. Wind blowing across the water transfers energy to that water. The energy first creates tiny ripples, which make an uneven surface for the wind to catch so that it may create larger waves. These waves travel across the ocean out of the area where the wind is blowing. Remember that a wave is a transfer of energy. Do you think the same molecules of water that start out in a wave in the middle of the ocean later arrive at the shore? The molecules are not the same, but the energy is transferred across the ocean. "
A wave breaks because,(A) the base has friction with the bottom (B) it becomes too tall to be supported by its base (C) it reaches the shore (D) all of these,D,"When does a wave break? Do waves only break when they reach shore? Waves break when they become too tall to be supported by their base. This can happen at sea but happens predictably as a wave moves up a shore. The energy at the bottom of the wave is lost by friction with the ground, so that the bottom of the wave slows down but the top of the wave continues at the same speed. The crest falls over and crashes down. "
Upwelling brings,(A) warm water to the surface so there are coral reefs (B) cold water east to west across the Pacific (C) nutrients to the surface so there is a lot of life (D) none of these,C,"Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling (Figure 1.2). Upwelling forces denser water from below to take the place of less dense water at the surface that is pushed away by the wind. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column. Upwelling brings those nutrients to the surface. Those nutrients support the growth of plankton and form the base of a rich ecosystem. California, South America, South Africa, and the Arabian Sea all benefit from offshore upwelling. Upwelling also takes place along the Equator between the North and South Equatorial Currents. Winds blow the surface water north and south of the Equator, so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Click image to the left or use the URL below. URL: "
The highest point of a wave is its amplitude.,(A) true (B) false,B,"Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. "
Wavelength is the difference between a crest and a trough.,(A) true (B) false,B,Energy is transmitted in waves. Every wave has a high point called a crest and a low point called a trough. The height of a wave from the center line to its crest is its amplitude. The distance between waves from crest to crest (or trough to trough) is its wavelength. The parts of a wave are illustrated in Figure 1.1. 
The biggest ocean waves occur with hurricanes.,(A) true (B) false,A,"Damage from hurricanes comes from the high winds, rainfall, and storm surge. Storm surge occurs as the storms low pressure center comes onto land, causing the sea level to rise unusually high. A storm surge is often made worse by the hurricanes high winds blowing seawater across the ocean onto the shoreline. Flooding can be devastating, especially along low-lying coastlines such as the Atlantic and Gulf Coasts. Hurricane Camille in 1969 had a 7.3 m (24 foot) storm surge that traveled 125 miles (200 km) inland. "
The greatest cause of tides is the Sun.,(A) true (B) false,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
Waves break on shore because the water is shallow.,(A) true (B) false,A,"Figure 14.10 shows what happens to waves near shore. As waves move into shallow water, they start to touch the bottom. The base of the waves drag and slow. Soon the waves slow down and pile up. They get steeper and unstable as the top moves faster than the base. When they reach the shore, the waves topple over and break. "
Tides are waves: high tide is the crest and low tide is the trough.,(A) true (B) false,A,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
All waves are caused by winds.,(A) true (B) false,B,"Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure 14.9 shows how water molecules move when a wave goes by. "
Tides cause water levels to rise and fall once a day.,(A) true (B) false,B,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
A wave is a transfer of energy that initially began with wind.,(A) true (B) false,A,"Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure 14.9 shows how water molecules move when a wave goes by. "
The difference between high and low tides is the tidal range.,(A) true (B) false,A,"The tidal range is the difference between the ocean level at high tide and the ocean level at low tide (Figure 1.2). The tidal range in a location depends on a number of factors, including the slope of the seafloor. Water appears to move a greater distance on a gentle slope than on a steep slope. "
The first sign of a tsunami is coming is high water moving fast across the ocean.,(A) true (B) false,B,"Tsunami waves have small wave heights relative to their long wavelengths, so they are usually unnoticed at sea. When traveling up a slope onto a shoreline, the wave is pushed upward. As with wind waves, the speed of the bottom of the wave is slowed by friction. This causes the wavelength to decrease and the wave to become unstable. These factors can create an enormous and deadly wave. Landslides, meteorite impacts, or any other jolt to ocean water may form a tsunami. Tsunami can travel at speeds of 800 kilometers per hour (500 miles per hour). "
Coriolis effect is caused by Earths rotation.,(A) true (B) false,A,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
The suns gravity is the main cause of Earths tides.,(A) true (B) false,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
Spring tides occur when the sun and moon are in a straight line.,(A) true (B) false,A,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
The Coriolis effect causes surface currents to flow diagonally across the ocean.,(A) true (B) false,A,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
There two high tides and two low tides every,(A) day (B) week (C) month (D) year,A,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
The main cause of tides is,(A) differences in water density (B) prevailing winds (C) Coriolis effect (D) gravity,D,"Figure 14.13 shows why tides occur. The main cause of tides is the pull of the Moons gravity on Earth. The pull is greatest on whatever is closest to the Moon. Although the gravity pulls the land, only the water can move. As a result: Water on the side of Earth facing the Moon is pulled hardest by the Moons gravity. This causes a bulge of water on that side of Earth. That bulge is a high tide. Earth itself is pulled harder by the Moons gravity than is the ocean on the side of Earth opposite the Moon. As a result, there is bulge of water on the opposite side of Earth. This creates another high tide. With water bulging on two sides of Earth, theres less water left in between. This creates low tides on the other two sides of the planet. "
Neap tides occur when the sun and moon are,(A) lined up with each other (B) at right angles to each other (C) on opposite sides of Earth from each other (D) none of the above,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
Spring tides have the,(A) highest low tide (B) greatest tidal range (C) least difference between high and low tides (D) two of the above,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
The Gulf Stream is a(n),(A) river in Florida (B) area of upwelling (C) deep ocean current (D) surface ocean current,D,"Surface currents play an enormous role in Earths climate. Even though the Equator and poles have very different climates, these regions would have more extremely different climates if ocean currents did not transfer heat from the equatorial regions to the higher latitudes. The Gulf Stream is a river of warm water in the Atlantic Ocean, about 160 kilometers wide and about a kilometer deep. Water that enters the Gulf Stream is heated as it travels along the Equator. The warm water then flows up the east coast of North America and across the Atlantic Ocean to Europe (see opening image). The energy the Gulf Stream transfers is enormous: more than 100 times the worlds energy demand. The Gulf Streams warm waters raise temperatures in the North Sea, which raises the air temperatures over land between 3 to 6 C (5 to 11 F). London, U.K., for example, is at about six degrees further south than Quebec, Canada. However, Londons average January temperature is 3.8 C (38 F), while Quebecs is only -12 C (10 F). Because air traveling over the warm water in the Gulf Stream picks up a lot of water, London gets a lot of rain. In contrast, Quebec is much drier and receives its precipitation as snow. Quebec City, Quebec in winter. Click image to the left or use the URL below. URL: "
Which of the following statements about upwelling is false?,(A) Upwelling brings a lot of nutrients to the surface (B) Many organisms live in an area where upwelling occurs (C) Upwelling occurs where wind blows surface water toward shore (D) none of the above,C,"Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling (Figure 1.2). Upwelling forces denser water from below to take the place of less dense water at the surface that is pushed away by the wind. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column. Upwelling brings those nutrients to the surface. Those nutrients support the growth of plankton and form the base of a rich ecosystem. California, South America, South Africa, and the Arabian Sea all benefit from offshore upwelling. Upwelling also takes place along the Equator between the North and South Equatorial Currents. Winds blow the surface water north and south of the Equator, so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Click image to the left or use the URL below. URL: "
Ocean water is denser when it is,(A) warmer (B) colder (C) saltier (D) two of the above,D,"Currents also flow deep below the surface of the ocean. Deep currents are caused by differences in density at the top and bottom. Density is defined as the amount of mass per unit of volume. More dense water takes up less space than less dense water. It has the same mass but less volume. Water that is more dense sinks. Less dense water rises. What can make water more dense? Water becomes more dense when it is colder and when it has more salt. In the North Atlantic Ocean, cold winds chill the water at the surface. Sea ice grows in this cold water, but ice is created from fresh water. The salt is left behind in the seawater. This cold, salty water is very dense, so it sinks to the bottom of the North Atlantic. Downwelling can take place in other places where surface water becomes very dense (see Figure 14.17). When water sinks it pushes deep water along at the bottom of the ocean. This water circulates through all of the ocean basins in deep currents. "
daily change in the level of ocean water,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,C,The ocean is huge but even this body of water is becoming seriously polluted. Climate change also affects the quality of ocean water for living things. 
stream of moving water that flows through the ocean,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,G,"Another way ocean water moves is in currents. A current is a stream of moving water that flows through the ocean. Surface currents are caused mainly by winds, but not the winds that blow and change each day. Surface currents are caused by the major wind belts that blow in the same direction all the time. The major surface currents are shown in Figure 14.15. They flow in a clockwise direction in the Northern Hemi- sphere. In the Southern Hemisphere, they flow in the opposite direction. "
tide that occurs during the first or third quarter of the moon,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
transfer of energy through matter,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,E,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
tide that occurs during a full moon or new moon,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,D,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
movement of deep ocean water to the surface,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,A,"Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling (Figure 1.2). Upwelling forces denser water from below to take the place of less dense water at the surface that is pushed away by the wind. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column. Upwelling brings those nutrients to the surface. Those nutrients support the growth of plankton and form the base of a rich ecosystem. California, South America, South Africa, and the Arabian Sea all benefit from offshore upwelling. Upwelling also takes place along the Equator between the North and South Equatorial Currents. Winds blow the surface water north and south of the Equator, so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Click image to the left or use the URL below. URL: "
amount of mass per unit of volume,(A) upwelling (B) neap tide (C) tide (D) spring tide (E) wave (F) density (G) current,F,"The density of matter is actually the amount of matter in a given space. The amount of matter is measured by its mass, and the space matter takes up is measured by its volume. Therefore, the density of matter can be calculated with this formula: Density = mass volume Assume, for example, that a book has a mass of 500 g and a volume of 1000 cm3 . Then the density of the book is: Density = 500 g = 0.5 g/cm3 1000 cm3 Q: What is the density of a liquid that has a volume of 30 mL and a mass of 300 g? A: The density of the liquid is: Density = 300 g = 10 g/mL 30 mL "
Only a tiny fraction of the ocean floor has ever been studied.,(A) true (B) false,A,"Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. "
The tallest mountains on Earth are located on the ocean floor.,(A) true (B) false,A,"As we have seen, the ocean floor is not flat: mid-ocean ridges, deep sea trenches, and other features all rise sharply above or plunge deeply below the abyssal plains. In fact, Earths tallest mountain is Mauna Kea volcano, which rises 10,203 m (33,476 ft.)meters) from the Pacific Ocean floor to become one of the volcanic mountains of Hawaii. The deepest canyon is also on the ocean floor, the Challenger Deep in the Marianas Trench, 10,916 m (35,814 ft). The continental margin is the transition from the land to the deep sea or, geologically speaking, from continental crust to oceanic crust. More than one-quarter of the ocean basin is continental margin. (Figure 1.3). Click image to the left or use the URL below. URL: "
Earths deepest canyon is the Grand Canyon in the American Southwest.,(A) true (B) false,B,"The Grand Canyon provides an excellent illustration of the principles above. The many horizontal layers of sedi- mentary rock illustrate the principle of original horizontality (Figure 1.3). The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition. Distinctive rock layers, such as the Kaibab Limestone, are matched across the broad expanse of the canyon. These rock layers were once connected, as stated by the rule of lateral continuity. The Colorado River cuts through all the layers of rock to form the canyon. Based on the principle of cross- cutting relationships, the river must be younger than all of the rock layers that it cuts through. "
Ocean water over the abyssal plain is shallow and warm.,(A) true (B) false,B,Oceanographers divide the ocean into zones both vertically and horizontally. 
The deepest ocean trench is 3 kilometers below sea level.,(A) true (B) false,B,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
The mid-ocean ridge is created by magma that cools and hardens.,(A) true (B) false,A,"Remember that the mid-ocean ridge is where hot mantle material upwells in a convection cell. The upwelling mantle melts due to pressure release to form lava. Lava flows at the surface cool rapidly to become basalt, but deeper in the crust, magma cools more slowly to form gabbro. The entire ridge system is made up of igneous rock that is either extrusive or intrusive. The seafloor is also igneous rock with some sediment that has fallen onto it. Earthquakes are common at mid-ocean ridges since the movement of magma and oceanic crust results in crustal shaking. Click image to the left or use the URL below. URL: "
Most of the ocean floor is too deep for organisms to live there.,(A) true (B) false,B,The ocean floor is rich in resources. The resources include both living and nonliving things. 
The only resources on or below the ocean floor are minerals such as manganese.,(A) true (B) false,B,The ocean floor is rich in resources. The resources include both living and nonliving things. 
Oil rigs floating on the ocean extract petroleum from sea water.,(A) true (B) false,B,"Oil spills are another source of ocean pollution. To get at oil buried beneath the seafloor, oil rigs are built in the oceans. These rigs pump oil from beneath the ocean floor. Huge ocean tankers carry oil around the world. If something goes wrong with a rig on a tanker, millions of barrels of oil may end up in the water. The oil may coat and kill ocean animals. Some of the oil will wash ashore. This oil may destroy coastal wetlands and ruin beaches. Figure 21.13 shows an oil spill on a beach. The oil washed ashore after a deadly oil rig explosion in the Gulf of Mexico in 2010. "
Hot water escapes through vents in the ocean floor.,(A) true (B) false,A,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
volcanic mountain on the ocean floor,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,F,"As we have seen, the ocean floor is not flat: mid-ocean ridges, deep sea trenches, and other features all rise sharply above or plunge deeply below the abyssal plains. In fact, Earths tallest mountain is Mauna Kea volcano, which rises 10,203 m (33,476 ft.)meters) from the Pacific Ocean floor to become one of the volcanic mountains of Hawaii. The deepest canyon is also on the ocean floor, the Challenger Deep in the Marianas Trench, 10,916 m (35,814 ft). The continental margin is the transition from the land to the deep sea or, geologically speaking, from continental crust to oceanic crust. More than one-quarter of the ocean basin is continental margin. (Figure 1.3). Click image to the left or use the URL below. URL: "
mostly flat part of the ocean floor under the open ocean,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,A,"Scientists have learned a lot about the ocean floor. For example, they know that Earths tallest mountains and deepest canyons are on the ocean floor. The major features on the ocean floor are described below. They are also shown in Figure 14.22. The continental shelf is the ocean floor nearest the edges of continents. It has a a gentle slope. The water over the continental shelf is shallow. The continental slope lies between the continental shelf and the abyssal plain. It has a steep slope with a sharp drop to the deep ocean floor. The abyssal plain forms much of the floor under the open ocean. It lies from 3 to 6 kilometers (1.9 to 3.7 miles) below the surface. Much of it is flat. An oceanic trench is a deep canyon on the ocean floor. Trenches occur where one tectonic plate subducts under another. The deepest trench is the Mariana Trench in the Pacific Ocean. It plunges more than 11 kilometers (almost 7 miles) below sea level. A seamount is a volcanic mountain on the ocean floor. Seamounts that rise above the water surface are known as islands. There are many seamounts dotting the seafloor. The mid-ocean ridge is a mountain range that runs through all the worlds oceans. It is almost 64,000 kilometers (40,000 miles) long! It forms where tectonic plates pull apart. Magma erupts through the ocean floor to make new seafloor. The magma hardens to create the ridge. "
deep canyon on the ocean floor,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,E,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
part of the ocean floor that lies between the continental shelf and abyssal plain,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,C,"Scientists have learned a lot about the ocean floor. For example, they know that Earths tallest mountains and deepest canyons are on the ocean floor. The major features on the ocean floor are described below. They are also shown in Figure 14.22. The continental shelf is the ocean floor nearest the edges of continents. It has a a gentle slope. The water over the continental shelf is shallow. The continental slope lies between the continental shelf and the abyssal plain. It has a steep slope with a sharp drop to the deep ocean floor. The abyssal plain forms much of the floor under the open ocean. It lies from 3 to 6 kilometers (1.9 to 3.7 miles) below the surface. Much of it is flat. An oceanic trench is a deep canyon on the ocean floor. Trenches occur where one tectonic plate subducts under another. The deepest trench is the Mariana Trench in the Pacific Ocean. It plunges more than 11 kilometers (almost 7 miles) below sea level. A seamount is a volcanic mountain on the ocean floor. Seamounts that rise above the water surface are known as islands. There are many seamounts dotting the seafloor. The mid-ocean ridge is a mountain range that runs through all the worlds oceans. It is almost 64,000 kilometers (40,000 miles) long! It forms where tectonic plates pull apart. Magma erupts through the ocean floor to make new seafloor. The magma hardens to create the ridge. "
mountain range that runs through all the worlds oceans,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,D,"Converging plates create the worlds largest mountain ranges. Each combination of plate types  continent- continent, continent-ocean, and ocean-ocean  creates mountains. "
structure on the ocean floor formed by minerals from hot water,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,G,"Oceanic crust is composed of mafic magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro (Figure 1.1). Gabbro from ocean crust. The gabbro is deformed because of intense faulting at the eruption site. Sediments, primarily mud and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore, where it comes off the continents in rivers and on wind currents. The oceanic crust is relatively thin and lies above the mantle. The cross section of oceanic crust in the Figure 1.2 shows the layers that grade from sediments at the top to extrusive basalt lava, to the sheeted dikes that feed lava to the surface, to deeper intrusive gabbro, and finally to the mantle. "
ocean floor near the edge of a continent,(A) abyssal plain (B) continental shelf (C) continental slope (D) mid-ocean ridge (E) oceanic trench (F) seamount (G) metallic chimney,B,"Scientists have learned a lot about the ocean floor. For example, they know that Earths tallest mountains and deepest canyons are on the ocean floor. The major features on the ocean floor are described below. They are also shown in Figure 14.22. The continental shelf is the ocean floor nearest the edges of continents. It has a a gentle slope. The water over the continental shelf is shallow. The continental slope lies between the continental shelf and the abyssal plain. It has a steep slope with a sharp drop to the deep ocean floor. The abyssal plain forms much of the floor under the open ocean. It lies from 3 to 6 kilometers (1.9 to 3.7 miles) below the surface. Much of it is flat. An oceanic trench is a deep canyon on the ocean floor. Trenches occur where one tectonic plate subducts under another. The deepest trench is the Mariana Trench in the Pacific Ocean. It plunges more than 11 kilometers (almost 7 miles) below sea level. A seamount is a volcanic mountain on the ocean floor. Seamounts that rise above the water surface are known as islands. There are many seamounts dotting the seafloor. The mid-ocean ridge is a mountain range that runs through all the worlds oceans. It is almost 64,000 kilometers (40,000 miles) long! It forms where tectonic plates pull apart. Magma erupts through the ocean floor to make new seafloor. The magma hardens to create the ridge. "
The main reason it is difficult to directly study the deep ocean floor is that the,(A) ocean floor has not been mapped (B) pressure is too high (C) distance is too far (D) water is too hot,B,"To better understand regions of the ocean, scientists define the water column by depth. They divide the entire ocean into two zones vertically, based on light level. Large lakes are divided into similar regions. Sunlight only penetrates the sea surface to a depth of about 200 m, creating the photic zone (""photic"" means light). Organisms that photosynthesize depend on sunlight for food and so are restricted to the photic zone. Since tiny photosynthetic organisms, known as phytoplankton, supply nearly all of the energy and nutrients to the rest of the marine food web, most other marine organisms live in or at least visit the photic zone. In the aphotic zone there is not enough light for photosynthesis. The aphotic zone makes up the majority of the ocean, but has a relatively small amount of its life, both in diversity of type and in numbers. The aphotic zone is subdivided based on depth (Figure 1.1). The average depth of the ocean is 3,790 m, a lot more shallow than the deep trenches but still an incredible depth for sea creatures to live in. What makes it so hard to live at the bottom of the ocean? The three major factors that make the deep ocean hard to inhabit are the absence of light, low temperature, and extremely high pressure. "
The ocean floor can be studied by scientists at the waters surface with,(A) submersibles (B) sonar devices (C) remote-control vehicles (D) two of the above,D,Scientists study the ocean floor in various ways. Scientists or their devices may actually travel to the ocean floor. Or they may study the ocean floor from the surface. One way is with a tool called sonar. 
"When using sonar, the distance to the ocean floor is calculated from the",(A) time it takes sound waves to travel to the ocean floor (B) pressure ocean water exerts on the ocean floor (C) speed of sound waves through ocean water (D) two of the above,D,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
The deepest oceanic trench occurs in the,(A) Atlantic Ocean (B) Pacific Ocean (C) Arctic Ocean (D) Indian Ocean,B,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
The mid-ocean ridge forms where tectonic plates,(A) slide past one another (B) push together (C) pull apart (D) subduct,C,"Plates move apart at mid-ocean ridges. Lava rises upward, erupts, and cools. Later, more lava erupts and pushes the original seafloor outward. This is seafloor spreading. Seafloor spreading forms new oceanic crust. The rising magma causes earthquakes. Most mid-ocean ridges are located deep below the sea. The island of Iceland sits right on the Mid-Atlantic ridge (Figure 6.17). "
Examples of minerals on the ocean floor include,(A) iron (B) copper (C) manganese (D) all of the above,D,The ocean floor is rich in resources. The resources include both living and nonliving things. 
Nodules on the ocean floor are,(A) deposits of petroleum (B) pockets of natural gas (C) fossils of organisms (D) balls of minerals,D,The ocean floor is rich in resources. The resources include both living and nonliving things. 
The three major groups of marine organisms include,(A) fish (B) worms (C) plankton (D) phytoplankton,C,"When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos. Figure 14.24 shows the three groups. "
What type of organism found in the ocean floats along with the current?,(A) plankton (B) whales (C) jellyfish (D) squids,A,"When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos. Figure 14.24 shows the three groups. "
Most plankton are,(A) able to swim (B) microscopic in size (C) found in the aphotic zone (D) able to move on their own,B,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
What part of a fishs body extracts oxygen from the water?,(A) bladder (B) gills (C) spleen (D) lungs,B,"In order to absorb oxygen from the water, fish use gills ( Figure 1.2). Gills take dissolved oxygen from water as the water flows over the surface of the gill. Gills help a fish breathe. "
All nekton,(A) are fish (B) can swim (C) live in the photic zone (D) live in the aphotic zone,B,"Nekton are living things that swim through the water. They may live at any depth, in the photic or aphotic zone. Most nekton are fish, although some are mammals. Fish have fins and streamlined bodies to help them swim. Fish also have gills to take oxygen from the water. Figure 14.26 shows examples of nekton. "
Benthic organisms that live in the intertidal must do which of the following,(A) have hard shells (B) have strong attachments (C) burrow into sediment (D) any of these,D,"Conditions in the intertidal zone change rapidly as water covers and uncovers the region and waves pound on the rocks. A great abundance of life is found in the intertidal zone (Figure 1.1). High energy waves hit the organisms that live in this zone, so they must be adapted to pounding waves and exposure to air during low tides. Hard shells protect from waves and also protect against drying out when the animal is above water. Strong attachments keep the animals anchored to the rock. In a tide pool, as in the photo, what organisms are found where and what specific adaptations do they have to that zone? The mussels on the top left have hard shells for protection and to prevent drying because they are often not covered by water. The sea anemones in the lower right are more often submerged and have strong attachments but can close during low tides. Many young organisms get their start in estuaries and so they must be adapted to rapid shifts in salinity. Organisms in a tide pool include sea stars and sea urchins. Click image to the left or use the URL below. URL: "
Coral reefs,(A) are found off of nearly all shorelines (B) are rocky outcroppings with little other life (C) have a tremendous amount of biodiversity (D) none of these,C,"The oceans provide a home to many living things. In fact, a greater number of organisms lives in the oceans than on land. Coral reefs, like the one in Figure 14.4, have more diversity of life forms than almost anywhere else on Earth. "
Marine organisms that move by crawling are,(A) nekton (B) benthos (C) plankton (D) zooplankton,B,"The variety and number of invertebrates, animals without a backbone, is truly remarkable (Figure 1.4). Marine invertebrates include sea slugs, sea anemones, starfish, octopuses, clams, sponges, sea worms, crabs, and lobsters. Most of these animals are found close to the shore, but they can be found throughout the ocean. Jellies are otherworldly creatures that glow in the dark, without brains or bones, some more than 100 feet long. Along with many other ocean areas, they live just off Californias coast. Click image to the left or use the URL below. URL: "
An example of a benthic organism is a,(A) sea anemone (B) whale shark (C) lion fish (D) fish larva,A,Benthos are living things on the ocean floor. Many benthic organisms attach themselves to rocks and stay in one place. This protects them from crashing waves and other water movements. Some benthic organisms burrow into sediments for food or protection. Benthic animals may crawl over the ocean floor. Examples of benthos include clams and worms. Figure 14.27 shows two other examples. Some benthos live near vents on the deep ocean floor. Tubeworms are an example (see Figure 14.28). Scalding hot water pours out of the vents. The hot water contains chemicals that some specialized bacteria can use to make food. Tubeworms let the bacteria live inside them. The bacteria get protection and the tubeworms get some of the food. 
Life in the deepest ocean is,(A) non-existent (B) abundant (C) about the same as at the surface (D) scarce,D,"The open ocean is a vast area. Food either washes down from the land or is created by photosynthesizing plankton. Zooplankton and larger animals feed on the phytoplankton and on each other. Larger animals such as whales and giant groupers may live their entire lives in the open water. How do fish survive in the deepest ocean? The few species that live in the greatest depths are very specialized (Figure 1.4). Since its rare to find a meal, the fish use very little energy; they move very little, breathe slowly, have minimal bone structure and a slow metabolism. These fish are very small. To maximize the chance of getting a meal, some species may have jaws that unhinge to accept a larger fish or backward-folding teeth to keep prey from escaping. Coral reefs are among the most densely inhabited and diverse areas on the globe. In this image of Maupiti Island in the South Pacific, the remnants of the volcano are surrounded by the circular reef. An 1896 drawing of a deep sea angler fish with a bioluminescent lure to attract prey. "
Tubeworms obtain food from,(A) algae (B) bacteria (C) sediments (D) phytoplankton,B,"Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. "
The most important producers in the ocean are,(A) plants (B) bacteria (C) zooplankton (D) phytoplankton,D,"Figure 14.29 shows a marine food chain. Phytoplankton form the base of the food chain. Phytoplankton are the most important primary producers in the ocean. They use sunlight and nutrients to make food by photosynthesis. Small zooplankton consume phytoplankton. Larger organisms eat the small zooplankton. Larger predators eat these consumers. In an unusual relationship, some enormous whales depend on plankton for their food. They filter tremendous amounts of these tiny creatures out of the water. The bacteria that make food from chemicals are also primary producers. These organisms do not do photosynthesis since there is no light at the vents. They do something called chemosynthesis. They break down chemicals to make food. When marine organisms die, decomposers break them down. This returns their nutrients to the water. The nutrients can be used again to make food. Decomposers in the oceans include bacteria and worms. Many live on the ocean floor. Do you know why? "
Nekton must live in the photic zone.,(A) true (B) false,B,"Nekton are living things that swim through the water. They may live at any depth, in the photic or aphotic zone. Most nekton are fish, although some are mammals. Fish have fins and streamlined bodies to help them swim. Fish also have gills to take oxygen from the water. Figure 14.26 shows examples of nekton. "
Zooplankton may include larvae of large animals.,(A) true (B) false,A,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
Plankton are organisms that can swim against the current.,(A) true (B) false,B,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
There is no photosynthesis at deep-sea vents because there is no light.,(A) true (B) false,A,"Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. Thats because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone. Water also gets colder as you go deeper. The weight of the water pressing down from above increases as well. At great depths, life becomes very difficult. The pressure is so great that only specially adapted creatures can live there. "
"If an ocean plant can photosynthesize, light must be available to the plant.",(A) true (B) false,A,"Only the top 200 meters or so of water receive enough sunlight for photosynthesis. This part of the water is called the photic zone. Below 200 meters, there is too little sunlight for photosynthesis to take place. This part of the water is called the aphotic zone. In this zone, food must come from other sources. It may be made by chemosynthesis, in which microorganisms use energy in chemicals instead of sunlight to make food. Or, food may drift down from the water above. "
All marine organisms are adapted to life in salt water.,(A) true (B) false,A,"Halophiles are organisms that ""love"" salt. They can survive in very salty water. For example, they have been found in the Great Salt Lake in Utah and the Dead Sea between Israel and Jordan. Both of these bodies of water are much saltier than the ocean. "
No marine organism can withstand the extreme water pressure at the bottom of the ocean.,(A) true (B) false,B,"Pressure is the amount of force acting on a given area. As you go deeper in the ocean, the pressure exerted by the water increases steadily. Thats because there is more and more water pressing down on you from above. The Figure 1.1 shows how pressure changes with depth. For each additional meter below the surface, pressure increases by 10 kPa. At 30 meters below the surface, the pressure is double the pressure at the surface. At a depth greater than 500 meters, the pressure is too great for humans to withstand without special equipment to protect them. At nearly 11,000 meters below the surface, the pressure is tremendous. "
Fish are the most numerous life forms in the ocean.,(A) true (B) false,B,"When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos. Figure 14.24 shows the three groups. "
Plankton range in size from bacteria to whales.,(A) true (B) false,B,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
Plankton always remain in one place because they cannot swim.,(A) true (B) false,B,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
Zooplankton feed on phytoplankton.,(A) true (B) false,A,"Figure 14.29 shows a marine food chain. Phytoplankton form the base of the food chain. Phytoplankton are the most important primary producers in the ocean. They use sunlight and nutrients to make food by photosynthesis. Small zooplankton consume phytoplankton. Larger organisms eat the small zooplankton. Larger predators eat these consumers. In an unusual relationship, some enormous whales depend on plankton for their food. They filter tremendous amounts of these tiny creatures out of the water. The bacteria that make food from chemicals are also primary producers. These organisms do not do photosynthesis since there is no light at the vents. They do something called chemosynthesis. They break down chemicals to make food. When marine organisms die, decomposers break them down. This returns their nutrients to the water. The nutrients can be used again to make food. Decomposers in the oceans include bacteria and worms. Many live on the ocean floor. Do you know why? "
Some nekton are mammals.,(A) true (B) false,A,"Nekton are living things that swim through the water. They may live at any depth, in the photic or aphotic zone. Most nekton are fish, although some are mammals. Fish have fins and streamlined bodies to help them swim. Fish also have gills to take oxygen from the water. Figure 14.26 shows examples of nekton. "
Fish swim with their fins and gills.,(A) true (B) false,B,"You can see some of the aquatic adaptations of fish in Figure 13.7. For a video introduction to aquatic adaptations of fish, go to this link:  . MEDIA Click image to the left or use the URL below. URL:  Fish are covered with scales. Scales are overlapping tissues, like shingles on a roof. They reduce friction with the water. They also provide a flexible covering that lets fish move their body to swim. Fish have gills. Gills are organs behind the head that absorb oxygen from water. Water enters through the mouth, passes over the gills, and then exits the body. Fish typically have a stream-lined body. This reduces water resistance. Most fish have fins. Fins function like paddles or rudders. They help fish swim and navigate in the water. Most fish have a swim bladder. This is a balloon-like organ containing gas. By inflating or deflating their swim bladder, fish can rise or sink in the water. "
Many benthic organisms attach themselves to rocks.,(A) true (B) false,A,Benthos are living things on the ocean floor. Many benthic organisms attach themselves to rocks and stay in one place. This protects them from crashing waves and other water movements. Some benthic organisms burrow into sediments for food or protection. Benthic animals may crawl over the ocean floor. Examples of benthos include clams and worms. Figure 14.27 shows two other examples. Some benthos live near vents on the deep ocean floor. Tubeworms are an example (see Figure 14.28). Scalding hot water pours out of the vents. The hot water contains chemicals that some specialized bacteria can use to make food. Tubeworms let the bacteria live inside them. The bacteria get protection and the tubeworms get some of the food. 
Sea cucumbers live on the ocean floor.,(A) true (B) false,A,Sea cucumbers at National Geographic http://animals.nationalgeographic.com/animals/invertebrates/sea-cucu 1. Where do sea cucumbers live? 2. How do sea cucumbers eat? 
marine organisms that swim,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,B,"While almost all echinoderms live on the sea floor, some sea-lilies can swim at great speeds for brief periods of time, and a few sea cucumbers are fully floating. Some echinoderms find other ways of moving. For example, crinoids attach themselves to floating logs, and some sea cucumbers move by attaching to the sides of fish. On the underside side of a sea star, there are hundreds of tiny feet usually arranged into several rows on each ray of the star. These are called tube feet, or podia, and are filled with seawater in most echinoderms. The water vascular system within the body of the animal is also filled with seawater. By expanding and contracting chambers within the water vascular system, the echinoderm can force water into certain tube feet to extend them. The animal has muscles in the tube feet, which are used to retract them. By expanding and retracting the right tube feet in the proper order, the animal can walk. "
example of zooplankton,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,G,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
name for plant-like plankton,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,C,"Plankton are organisms that cannot swim but that float along with the current. The word ""plankton"" comes from the Greek for wanderer. Most plankton are microscopic, but some are visible to the naked eye (Figure 1.1). Phytoplankton are tiny plants that make food by photosynthesis. Because they need sunlight, phytoplankton live in the photic zone. Phytoplankton are responsible for about half of the total primary productivity (food energy) on Earth. Like other plants, phytoplankton release oxygen as a waste product. Microscopic diatoms are a type of phyto- plankton. Zooplankton, or animal plankton, eat phytoplankton as their source of food (Figure 1.2). Some zooplankton live as plankton all their lives and others are juvenile forms of animals that will attach to the bottom as adults. Some small invertebrates live as zooplankton. Copepods are abundant and so are an important food source for larger animals. "
name for animal-like plankton,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,E,"Plankton are organisms that cannot swim but that float along with the current. The word ""plankton"" comes from the Greek for wanderer. Most plankton are microscopic, but some are visible to the naked eye (Figure 1.1). Phytoplankton are tiny plants that make food by photosynthesis. Because they need sunlight, phytoplankton live in the photic zone. Phytoplankton are responsible for about half of the total primary productivity (food energy) on Earth. Like other plants, phytoplankton release oxygen as a waste product. Microscopic diatoms are a type of phyto- plankton. Zooplankton, or animal plankton, eat phytoplankton as their source of food (Figure 1.2). Some zooplankton live as plankton all their lives and others are juvenile forms of animals that will attach to the bottom as adults. Some small invertebrates live as zooplankton. Copepods are abundant and so are an important food source for larger animals. "
general term for marine organisms that float on water,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,D,Plankton are living things that float in the water. Most plankton are too small to see with the unaided eye. Some examples are shown in Figure 14.25. Plankton are unable to move on their own. Ocean motions carry them along. There are two main types of plankton: 1. Phytoplankton are plant-like plankton. They make food by photosynthesis. They live in the photic zone. Most are algae. 2. Zooplankton are animal-like plankton. They feed on phytoplankton. They include tiny animals and fish larvae. 
organisms that live on the ocean floor,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,A,"The ocean floor is home to many species of living things. Some from shallow water are used by people for food. Clams and some fish are among the many foods we get from the ocean floor. Some living things on the ocean floor are sources of human medicines. For example, certain bacteria on the ocean floor produce chemicals that fight cancer. "
example of phytoplankton,(A) benthos (B) nekton (C) phytoplankton (D) plankton (E) zooplankton (F) alga (G) fish larva,F,"Plankton are organisms that cannot swim but that float along with the current. The word ""plankton"" comes from the Greek for wanderer. Most plankton are microscopic, but some are visible to the naked eye (Figure 1.1). Phytoplankton are tiny plants that make food by photosynthesis. Because they need sunlight, phytoplankton live in the photic zone. Phytoplankton are responsible for about half of the total primary productivity (food energy) on Earth. Like other plants, phytoplankton release oxygen as a waste product. Microscopic diatoms are a type of phyto- plankton. Zooplankton, or animal plankton, eat phytoplankton as their source of food (Figure 1.2). Some zooplankton live as plankton all their lives and others are juvenile forms of animals that will attach to the bottom as adults. Some small invertebrates live as zooplankton. Copepods are abundant and so are an important food source for larger animals. "
A campfire warms the campers sitting around it by conduction.,(A) true (B) false,B,Energy can move from one place to another. It can travel through space or matter. Thats why you can feel the heat of a campfire and see its light. These forms of energy travel from the campfire to you. 
When heat is transferred by the movement of electromagnetic waves it is called,(A) convection (B) conduction (C) radiation (D) none of these,C,"Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electro- magnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation. Electromagnetic waves can transfer energy through matter or across empty space. Click image to the left or use the URL below. URL:  Q: How do microwaves transfer energy inside a microwave oven? A: They transfer energy through the air inside the oven to the food. "
Energy can travel only through matter.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
Electromagnetic spectrum,(A) is all visible to humans (B) has the highest energy at the short wavelengths (C) has the highest energy in the infrared (D) is only able to travel through material,B,"Electromagnetic radiation occurs in waves of different wavelengths and frequencies. Infrared light and visible light make up just a small part of the full range of electromagnetic radiation, which is called the electromagnetic spectrum. The electromagnetic spectrum is summarized in the diagram in Figure 21.7. On the far left of the diagram are radio waves, which include microwaves. They have the longest wavelengths and lowest frequencies of all electromagnetic waves. They also have the least amount of energy. On the far right are X rays and gamma rays. The have the shortest wavelengths and highest frequencies of all electromagnetic waves. They also have the greatest amount of energy. Between these two extremes, wavelength, frequency, and energy change continuously from one side of the spectrum to the other. Waves in this middle section of the electromagnetic spectrum are commonly called light. As you will read below, the properties of electromagnetic waves influence how the different waves behave and how they can be used. "
Most of the energy on Earth comes from the sun.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
The vertical movement of air due to the uneven heating is called,(A) convection (B) reflection (C) conduction (D) refraction,A,"Air movement takes place in the troposphere. This is the lowest layer of the atmosphere. Air moves because of differences in heating. These differences create convection currents and winds. Figure 15.19 shows how this happens. Air in the troposphere is warmer near the ground. The warm air rises because it is light. The light, rising air creates an area of low air pressure at the surface. The rising air cools as it reaches the top of the troposphere. The air gets denser, so it sinks to the surface. The sinking, heavy air creates an area of high air pressure near the ground. Air always flows from an area of higher pressure to an area of lower pressure. Air flowing over Earths surface is called wind. The greater the difference in pressure, the stronger the wind blows. "
Wavelengths that are short and very high energy are,(A) infrared (B) radio waves (C) ultraviolet (D) visible light,C,"The shortest-wavelength, highest-frequency electromagnetic waves are X rays and gamma rays. These rays have so much energy that they can pass through many materials. This makes them potentially very harmful, but it also makes them useful for certain purposes. "
The electromagnetic spectrum is the range of wavelengths of visible light.,(A) true (B) false,B,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
Light with the most energy is infrared light.,(A) true (B) false,B,"Light with the longest wavelengths is called infrared light. The term infrared means below red. Infrared light is the range of light waves that have longer wavelengths and lower frequencies than red light in the visible range of light waves. The sun gives off infrared light as do flames and living things. You cant see infrared light waves, but you can feel them as heat. But infrared cameras and night vision goggles can detect infrared light waves and convert them to visible images. "
Incoming solar radiation may,(A) reflect back into space (B) be absorbed by clouds (C) strike the ground (D) all of these,D,"The amount of energy the Sun radiates is variable. Sunspots are magnetic storms on the Suns surface that increase and decrease over an 11-year cycle (Figure 1.1). When the number of sunspots is high, solar radiation is also relatively high. But the entire variation in solar radiation is tiny relative to the total amount of solar radiation that there is, and there is no known 11-year cycle in climate variability. The Little Ice Age corresponded to a time when there were no sunspots on the Sun. Sunspots on the face of the Sun. "
Gamma rays do not penetrate Earths atmosphere.,(A) true (B) false,A,"Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect living things on Earth if they werent absorbed by the atmosphere. A: Gamma rays would destroy most living things on Earth because they have so much energy. "
Warmer molecules have more energy than cooler ones.,(A) true (B) false,A,"In conduction, heat is transferred from molecule to molecule by contact. Warmer molecules vibrate faster than cooler ones. They bump into the cooler molecules. When they do they transfer some of their energy. Conduction happens mainly in the lower atmosphere. Can you explain why? "
Conduction happens mainly in the upper atmosphere.,(A) true (B) false,B,"In conduction, heat is transferred from molecule to molecule by contact. Warmer molecules vibrate faster than cooler ones. They bump into the cooler molecules. When they do they transfer some of their energy. Conduction happens mainly in the lower atmosphere. Can you explain why? "
Warm air always sinks to the surface in a convection current.,(A) true (B) false,B,"Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earths surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current, like the one in Figure 15.9. Convection is the most important way that heat travels in the atmosphere. "
The greenhouse effect causes more solar energy to reach Earths surface.,(A) true (B) false,B,"When sunlight heats Earths surface, some of the heat radiates back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere. This is the greenhouse effect, and it helps to keep Earth warm. The greenhouse effect allows Earth to have temperatures that can support life. Gases that absorb heat in the atmosphere are called greenhouse gases. They include carbon dioxide and water vapor. Human actions have increased the levels of greenhouse gases in the atmosphere. This is shown in Figure 15.11. The added gases have caused a greater greenhouse effect. How do you think this affects Earths temperature? "
Energy cannot be created or destroyed.,(A) true (B) false,A,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
ability to do work,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,E,What explains all of these events? The answer can be summed up in one word: energy. Energy is defined as the ability to do work. Doing anything takes energy. A campfire obviously has energy. You can feel its heat and see its light. 
Two important greenhouse gases are carbon dioxide and water vapor.,(A) true (B) false,A,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
tiny packet of energy,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,D,The Sun gives off energy in tiny packets called photons. Photons travel in waves. Figure 15.7 models a wave of light. Notice the wavelength in the figure. Waves with shorter wavelengths have more energy. 
transfer of energy by a current,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,B,"Electrical energy is transmitted by moving electrons in an electric current. In order to travel, electric current needs matter. It cannot pass through empty space. However, matter resists the flow of electric current. Thats because flowing electrons in current collide with particles of matter, which absorb their energy. Some types of matter offer more or less resistance to electric current than others. "
"Sunlight hits Earth surface, then heat travels by conduction back into the atmosphere.",(A) true (B) false,A,"Heat moves in the atmosphere the same way it moves through the solid Earth or another medium. What follows is a review of the way heat flows, but applied to the atmosphere. Radiation is the transfer of energy between two objects by electromagnetic waves. Heat radiates from the ground into the lower atmosphere. In conduction, heat moves from areas of more heat to areas of less heat by direct contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their energy. In the atmosphere, conduction is more effective at lower altitudes, where air density is higher. This transfers heat upward to where the molecules are spread further apart or transfers heat laterally from a warmer to a cooler spot, where the molecules are moving less vigorously. Heat transfer by movement of heated materials is called convection. Heat that radiates from the ground initiates convection cells in the atmosphere (Figure 1.1). Click image to the left or use the URL below. URL: "
transfer of energy by waves through air or empty space,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,A,"Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Suns energy travels through space by radiation. After sunlight heats the planets surface, some heat radiates back into the atmosphere. "
Deep purple is part of the ultraviolet spectrum.,(A) true (B) false,B,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
Burning wood releases chemical energy.,(A) true (B) false,A,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
light with wavelengths too long for humans to see,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,F,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
transfer of energy by direct contact between molecules,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,G,"In conduction, heat is transferred from molecule to molecule by contact. Warmer molecules vibrate faster than cooler ones. They bump into the cooler molecules. When they do they transfer some of their energy. Conduction happens mainly in the lower atmosphere. Can you explain why? "
light with wavelengths too short for humans to see,(A) radiation (B) convection (C) ultraviolet light (D) photon (E) energy (F) infrared light (G) conduction,C,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
Forms of energy include,(A) electrical energy (B) chemical energy (C) light energy (D) all of the above,D,"Energy, or the ability to cause changes in matter, can exist in many different forms. Energy can also change from one form to another. The photo above of the guitar player represents six forms of energy: mechanical, chemical, electrical, light, thermal, and sound energy. Another form of energy is nuclear energy. Q: Can you find the six different forms of energy in the photo of the guitar player (See opening image)? A: The guitarist uses mechanical energy to pluck the strings of the guitar. He gets the energy he needs to perform from chemical energy in food he ate earlier in the day. The stage lights use electrical energy, which they change to light energy and thermal energy (commonly called heat). The guitar produces sound energy when the guitarist plucks the strings. "
Which statement about energy is false?,(A) Energy can change form (B) Energy can be created (C) Energy can do work (D) Energy can travel,B,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
Convection occurs in,(A) gases (B) solids (C) liquids (D) two of the above,D,"Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earths surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current, like the one in Figure 15.9. Convection is the most important way that heat travels in the atmosphere. "
Energy can travel through space by,(A) conduction (B) convection (C) radiation (D) two of the above,C,"Energy travels through space or material. Heat energy is transferred in three ways: radiation, conduction, and convection. "
Differences in solar energy by latitude result in,(A) winds (B) weather (C) ocean currents (D) all of the above,D,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
A greenhouse gas mainly absorbs heat that,(A) radiates directly from the sun (B) re-radiates from Earths surface (C) comes from burning fossil fuels (D) before it reaches Earths surface,B,"When sunlight heats Earths surface, some of the heat radiates back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere. This is the greenhouse effect, and it helps to keep Earth warm. The greenhouse effect allows Earth to have temperatures that can support life. Gases that absorb heat in the atmosphere are called greenhouse gases. They include carbon dioxide and water vapor. Human actions have increased the levels of greenhouse gases in the atmosphere. This is shown in Figure 15.11. The added gases have caused a greater greenhouse effect. How do you think this affects Earths temperature? "
The greenhouse effect is caused,(A) completely by human actions (B) partly by natural processes (C) only by carbon dioxide (D) two of the above,B,"The exception to Earths temperature being in balance is caused by greenhouse gases. But first the role of greenhouse gases in the atmosphere must be explained. Greenhouse gases warm the atmosphere by trapping heat. Some of the heat that radiates out from the ground is trapped by greenhouse gases in the troposphere. Like a blanket on a sleeping person, greenhouse gases act as insulation for the planet. The warming of the atmosphere because of insulation by greenhouse gases is called the greenhouse effect (Figure 1.1). Greenhouse gases are the component of the atmosphere that moderate Earths temperatures. "
layer of the atmosphere above the troposphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,C,The stratosphere is the layer above the troposphere. The layer rises to about 50 kilometers (31 miles) above the surface. 
layer of the atmosphere above the mesosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,D,The mesosphere is the layer above the stratosphere. It rises to about 85 kilometers (53 miles) above the surface. Temperature decreases with altitude in this layer. 
boundary between the troposphere and stratosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,F,At the top of the stratosphere is a thin layer called the stratopause. It acts as a boundary between the stratosphere and the mesosphere. 
layer of the atmosphere above the thermosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,A,The thermosphere is the layer above the mesosphere. It rises to 600 kilometers (372 miles) above the surface. The International Space Station orbits Earth in this layer as in Figure 15.16. 
boundary between the stratosphere and mesosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,G,At the top of the stratosphere is a thin layer called the stratopause. It acts as a boundary between the stratosphere and the mesosphere. 
lowest layer of the atmosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,E,"Look at the troposphere in Figure 15.12. This is the shortest layer of the atmosphere. It rises to only about 12 kilometers (7 miles) above the surface. Even so, this layer holds 75 percent of all the gas molecules in the atmosphere. Thats because the air is densest in this layer. "
layer of the atmosphere above the stratosphere,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere (E) troposphere (F) tropopause (G) stratopause,B,The stratosphere is the layer above the troposphere. The layer rises to about 50 kilometers (31 miles) above the surface. 
Earths atmosphere is divided into layers based on,(A) density (B) pressure (C) composition (D) temperature,D,"The atmosphere is divided into layers based on how the temperature in that layer changes with altitude, the layers temperature gradient (Figure 1.2). The temperature gradient of each layer is different. In some layers, temperature increases with altitude and in others it decreases. The temperature gradient in each layer is determined by the heat source of the layer (See opening image). The four main layers of the atmosphere have different temperature gradients, cre- ating the thermal structure of the atmo- sphere. This video is very thorough in its discussion of the layers of the atmosphere. Remember that the chemical composi- tion of each layer is nearly the same except for the ozone layer that is found in the stratosphere. Click image to the left or use the URL below. URL: "
The shortest layer of the atmosphere is the,(A) exosphere (B) mesosphere (C) troposphere (D) thermosphere,C,"Look at the troposphere in Figure 15.12. This is the shortest layer of the atmosphere. It rises to only about 12 kilometers (7 miles) above the surface. Even so, this layer holds 75 percent of all the gas molecules in the atmosphere. Thats because the air is densest in this layer. "
The tropopause prevents cool air in the troposphere from mixing with,(A) warm air in the stratosphere (B) hot air in the thermosphere (C) cold air in the mesosphere (D) cold air in the exosphere,A,At the top of the troposphere is a thin layer of air called the tropopause. You can see it in Figure 15.12. This layer acts as a barrier. It prevents cool air in the troposphere from mixing with warm air in the stratosphere. 
Which sentence about ozone is false?,(A) The splitting of ozone molecules warms the mesosphere (B) Ozone protects Earths surface from harmful radiation (C) A molecule of ozone consists of three oxygen atoms (D) Ozone molecules absorb ultraviolet light,A,"At this point you might be asking yourself, Is ozone bad or is ozone good? There is no simple answer to that question: It depends on where the ozone is located (Figure 1.1). In the troposphere, ozone is a pollutant. In the ozone layer in the stratosphere, ozone screens out high energy ultraviolet radiation and makes Earth habitable. "
Temperature decreases as altitude increases in the,(A) mesosphere (B) stratosphere (C) thermosphere (D) two of the above,A,"Air temperature changes as altitude increases. In some layers of the atmosphere, the temperature decreases. In other layers, it increases. You can see this in Figure 15.12. Refer to this figure as you read about the layers below. "
The coldest temperatures in the atmosphere occur in the,(A) mesopause (B) tropopause (C) stratopause (D) none of the above,A,At the top of the mesosphere is the mesopause. Temperatures here are colder than anywhere else in the atmosphere. They are as low as -100 C (-212 F)! Nowhere on Earths surface is that cold. 
The International Space Station orbits Earth in the,(A) exosphere (B) mesosphere (C) stratosphere (D) thermosphere,D,"The International Space Station, shown in Figure 23.24 is a joint project between the space agencies of many nations These include the United States (NASA), Russia (RKA), Japan (JAXA), Canada (CSA), several European countries (ESA) and the Brazilian Space Agency. The International Space Station is a very large station. It has many different sections and is still being assembled. The station has had people on board since 2000. American space shuttles deliver most of the supplies and equipment to the station. Russian Soyuz spacecraft carry people. The primary purpose of the station is scientific research. This is important because the station has a microgravity environment. Experiments are done in the fields of biology, chemistry, physics, physiology and medicine. "
Most of the heat in the troposphere comes directly from the sun.,(A) true (B) false,B,"The troposphere is the lowest layer of the atmosphere. In it, temperature decreases with altitude. The troposphere gets some of its heat directly from the Sun. Most, however, comes from Earths surface. The surface is heated by the Sun and some of that heat radiates back into the air. This makes the temperature higher near the surface than at higher altitudes. "
Convection currents occur in all five layers of the atmosphere.,(A) true (B) false,B,"Convection is the transfer of heat by a current. Convection happens in a liquid or a gas. Air near the ground is warmed by heat radiating from Earths surface. The warm air is less dense, so it rises. As it rises, it cools. The cool air is dense, so it sinks to the surface. This creates a convection current, like the one in Figure 15.9. Convection is the most important way that heat travels in the atmosphere. "
Most of the heat that enters the mesosphere comes from the stratosphere.,(A) true (B) false,A,There are very few gas molecules in the mesosphere. This means that there is little matter to absorb the Suns rays and heat the air. Most of the heat that enters the mesosphere comes from the stratosphere below. Thats why the mesosphere is warmest at the bottom. 
Friction with gas molecules causes meteors to burn up in the atmosphere.,(A) true (B) false,A,"Did you ever see a meteor shower, like the one in Figure 15.15? Meteors burn as they fall through the mesosphere. The space rocks experience friction with the gas molecules. The friction makes the meteors get very hot. Many meteors burn up completely in the mesosphere. "
The troposphere rises to about 50 kilometers above Earths surface.,(A) true (B) false,B,The stratosphere is the layer above the troposphere. The layer rises to about 50 kilometers (31 miles) above the surface. 
The top of the mesosphere is warmer than the bottom.,(A) true (B) false,B,There are very few gas molecules in the mesosphere. This means that there is little matter to absorb the Suns rays and heat the air. Most of the heat that enters the mesosphere comes from the stratosphere below. Thats why the mesosphere is warmest at the bottom. 
The aurora borealis occurs because of storms on Earths surface.,(A) true (B) false,B,"Have you ever seen a brilliant light show in the night sky? Sometimes the ions in the thermosphere glow at night. Storms on the Sun energize the ions and make them light up. In the Northern Hemisphere, the lights are called the northern lights, or aurora borealis. In the Southern Hemisphere, they are called southern lights, or aurora australis. "
The thermosphere contains charged particles called ions.,(A) true (B) false,A,"Within the thermosphere is the ionosphere. The ionosphere gets its name from the solar radiation that ionizes gas molecules to create a positively charged ion and one or more negatively charged electrons. The freed electrons travel within the ionosphere as electric currents. Because of the free ions, the ionosphere has many interesting characteristics. At night, radio waves bounce off the ionosphere and back to Earth. This is why you can often pick up an AM radio station far from its source at night. "
The exosphere merges gradually with outer space.,(A) true (B) false,A,"The exosphere is the layer above the thermosphere. This is the top of the atmosphere. The exosphere has no real upper limit; it just gradually merges with outer space. Gas molecules are very far apart in this layer, but they are really hot. Earths gravity is so weak in the exosphere that gas molecules sometimes just float off into space. "
Gas molecules in the exosphere are extremely cold.,(A) true (B) false,B,"The density of molecules is so low in the thermosphere that one gas molecule can go about 1 km before it collides with another molecule. Since so little energy is transferred, the air feels very cold (See opening image). "
driest of all climates,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,D,"Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. The driest climates are deserts. Most occur between about 15 and 30 latitude. This is where dry air sinks to the surface in the global circulation cells. Deserts receive less than 25 centimeters (10 inches) of rain per year. They may be covered with sand dunes or be home to sparse but hardy plants (see Figure 17.11). With few clouds, deserts have hot days and cool nights. Other dry climates get a little more precipitation. They are called steppes. These regions have short grasses and low bushes (see Figure 17.11). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows. "
To figure out which climate zone you are in you should,(A) look at the plants (B) monitor the temperature of the region (C) monitor the precipitation of the region (D) understand the seasons of the region,A,"Climate zones are classified by the Kppen classification system. This system is based on the temperature, the amount of precipitation, and the times of year when precipitation occurs. Since climate determines the type of vegetation that grows in an area, vegetation is used as an indicator of climate type. "
climate found at very high altitudes,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,A,"Air temperature falls at higher altitudes. You can see this in Figure 17.6. Why does this happen? Since air is less dense at higher altitudes, its molecules are spread farther apart than they are at sea level. These molecules have fewer collisions, so they produce less heat. Look at the mountain in Figure 17.7. The peak of Mount Kilimanjaro, Tanzania (Africa, 3 south latitude) is 6 kilometers (4 miles) above sea level. At 3 S its very close to the equator. At the bottom of the mountain, the temperature is high year round. How can you tell that its much cooler at the top? "
Small areas with climates that differ from the surrounding area are known as?,(A) small climates (B) micro areas (C) microclimates (D) abnormalities,C,"When climate conditions in a small area are different from those of the surroundings, the climate of the small area is called a microclimate. The microclimate of a valley may be cool relative to its surroundings since cold air sinks. The ground surface may be hotter or colder than the air a few feet above it, because rock and soil gain and lose heat readily. Different sides of a mountain will have different microclimates. In the Northern Hemisphere, a south-facing slope receives more solar energy than a north-facing slope, so each side supports different amounts and types of vegetation. Altitude mimics latitude in climate zones. Climates and biomes typical of higher latitudes may be found in other areas of the world at high altitudes. Click image to the left or use the URL below. URL: "
climate that has short grasses and low bushes,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,F,"Pedocal soil forms where grasses and brush are common (Figure 9.11). The climate is drier, with less than 65 cm of rain per year. With less rain, there is less chemical weathering. There is less organic material and the soils are slightly less fertile. "
In what latitude zone are most of Earths deserts between?,(A) 0 and 15 (B) 15 and 30 (C) 30 and 45 (D) 45 and 60,B,"Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. The driest climates are deserts. Most occur between about 15 and 30 latitude. This is where dry air sinks to the surface in the global circulation cells. Deserts receive less than 25 centimeters (10 inches) of rain per year. They may be covered with sand dunes or be home to sparse but hardy plants (see Figure 17.11). With few clouds, deserts have hot days and cool nights. Other dry climates get a little more precipitation. They are called steppes. These regions have short grasses and low bushes (see Figure 17.11). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows. "
Dry climate zones,(A) receive no rainfall (B) experience more evaporation than precipitation (C) are all desert biomes (D) all of these,B,Dry climates have less precipitation than evaporation. Temperature: Abundant sunshine. Summer temperatures are high; winters are cooler and longer than in tropical moist climates. Rainfall: Irregular; several years of drought are often followed by a single year of abundant rainfall. Dry climates cover about 26% of the worlds land area. Low latitude deserts are found at the Ferrell cell high pressure zone. Higher latitude deserts occur within continents or in rainshadows. Vegetation is sparse but well adapted to the dry conditions. 
climate that has conifer forests,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,B,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
climate type that includes marine west coast climates,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,G,"Temperate climates have moderate temperatures. These climates vary in how much rain they get and when the rain falls. You can see different types of temperate climates in Figure 17.12. Mediterranean climates are found on the western coasts of continents. The latitudes are between 30 and 45. The coast of California has a Mediterranean climate. Temperatures are mild and rainfall is moderate. Most of the rain falls in the winter, and summers are dry. To make it through the dry summers, short woody plants are common. Marine west coast climates are also found on the western coasts of continents. They occur between 45 and 60 latitude. The coast of Washington State has this type of climate. Temperatures are mild and theres plenty of rainfall all year round. Dense fir forests grow in this climate. Humid subtropical climates are found on the eastern sides of continents between about 20 and 40 latitude. The southeastern U.S. has this type of climate. Summers are hot and humid, but winters are chilly. There is moderate rainfall throughout the year. Pine and oak forests grow in this climate. "
"Where it is dark and bitterly cold in winter,",(A) it is a polar climate (B) the ground is permanently frozen (C) there may be so little precipitation (D) it is a desert (E) d all of these,D,"Winter solstice for the Northern Hemisphere happens on December 21 or 22. The tilt of Earths axis points away from the Sun (Figure 1.3). Light from the Sun is spread out over a larger area, so that area isnt heated as much. With fewer daylight hours in winter, there is also less time for the Sun to warm the area. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. "
climate found on the coast of California,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,E,"When a place is near an ocean, the water can have a big effect on the climate. "
climate type that is found in inland areas of the Northern Hemisphere,(A) alpine tundra (B) subarctic climate (C) continental climate (D) desert (E) Mediterranean climate (F) steppe (G) temperate climate,C,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
Right around the equator is the one latitude with no glaciers.,(A) true (B) false,B,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
A valley could have a different microclimate from a hillside because cold air sinks.,(A) true (B) false,A,"A place might have a different climate than the major climate type around it. This is called a microclimate. Look at Figure 17.15. The south-facing side of the hill gets more direct sunlight than the north side of a hill. This gives the south side a warmer microclimate. A microclimate can be due to a place being deeper. Since cold air sinks, a depression in the land can be a lot colder than the land around it. "
The Southern Hemisphere has no lands with a continental climate.,(A) true (B) false,A,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
Coastal California has a Mediterranean climate with woody plants to survive dry summers.,(A) true (B) false,A,"Temperate climates have moderate temperatures. These climates vary in how much rain they get and when the rain falls. You can see different types of temperate climates in Figure 17.12. Mediterranean climates are found on the western coasts of continents. The latitudes are between 30 and 45. The coast of California has a Mediterranean climate. Temperatures are mild and rainfall is moderate. Most of the rain falls in the winter, and summers are dry. To make it through the dry summers, short woody plants are common. Marine west coast climates are also found on the western coasts of continents. They occur between 45 and 60 latitude. The coast of Washington State has this type of climate. Temperatures are mild and theres plenty of rainfall all year round. Dense fir forests grow in this climate. Humid subtropical climates are found on the eastern sides of continents between about 20 and 40 latitude. The southeastern U.S. has this type of climate. Summers are hot and humid, but winters are chilly. There is moderate rainfall throughout the year. Pine and oak forests grow in this climate. "
The Sonoran Desert has only a few sparse plants.,(A) true (B) false,B,"Each organism has the ability to survive in a specific environment. Dry desert environments are difficult to live in. Desert plants have special stems and leaves to conserve water. Animals have other ways to live in the desert. The Namib Desert receives only 1.5 inches of rainfall each year. The Namib Desert beetle lives there. How do the beetles get enough water to survive? Early morning fog deposits water droplets. The droplets collect on a beetles wings and back. The beetle tilts its rear end up. When the droplet is heavy enough, it slides forward. It lands in the beetles mouth. There are many other environments that need unique approaches for survival (Figure 12.10). "
Each type of climate is associated with certain types of living things.,(A) true (B) false,A,"Major climate types are based on temperature and precipitation. These two factors determine what types of plants can grow in an area. Animals and other living things depend on plants. So each climate is associated with certain types of living things. A major type of climate and its living things make up a biome. As you read about the major climate types below, find them on the map in Figure 17.9. "
All tropical climates have high rainfall year round.,(A) true (B) false,B,"Tropical climates are found around the equator. As youd expect, these climates have warm temperatures year round. Tropical climates may be very wet or wet and dry. Tropical wet climates occur at or very near the equator. They have high rainfall year round. Tropical rainforests grow in this type of climate. Tropical wet and dry climates occur between 5 and 20 latitude and receive less rainfall. Most of the rain falls in a single season. The rest of the year is dry. Few trees can withstand the long dry season, so the main plants are grasses (see Figure 17.10). "
A desert is any area that receives less than 50 cm of rainfall per year.,(A) true (B) false,B,"Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. The driest climates are deserts. Most occur between about 15 and 30 latitude. This is where dry air sinks to the surface in the global circulation cells. Deserts receive less than 25 centimeters (10 inches) of rain per year. They may be covered with sand dunes or be home to sparse but hardy plants (see Figure 17.11). With few clouds, deserts have hot days and cool nights. Other dry climates get a little more precipitation. They are called steppes. These regions have short grasses and low bushes (see Figure 17.11). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows. "
Steppes are dry because they occur between 15 and 30 degrees latitude.,(A) true (B) false,B,"Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. The driest climates are deserts. Most occur between about 15 and 30 latitude. This is where dry air sinks to the surface in the global circulation cells. Deserts receive less than 25 centimeters (10 inches) of rain per year. They may be covered with sand dunes or be home to sparse but hardy plants (see Figure 17.11). With few clouds, deserts have hot days and cool nights. Other dry climates get a little more precipitation. They are called steppes. These regions have short grasses and low bushes (see Figure 17.11). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows. "
Temperate climates vary in the amount and timing of precipitation they receive.,(A) true (B) false,A,"Temperate climates have moderate temperatures. These climates vary in how much rain they get and when the rain falls. You can see different types of temperate climates in Figure 17.12. Mediterranean climates are found on the western coasts of continents. The latitudes are between 30 and 45. The coast of California has a Mediterranean climate. Temperatures are mild and rainfall is moderate. Most of the rain falls in the winter, and summers are dry. To make it through the dry summers, short woody plants are common. Marine west coast climates are also found on the western coasts of continents. They occur between 45 and 60 latitude. The coast of Washington State has this type of climate. Temperatures are mild and theres plenty of rainfall all year round. Dense fir forests grow in this climate. Humid subtropical climates are found on the eastern sides of continents between about 20 and 40 latitude. The southeastern U.S. has this type of climate. Summers are hot and humid, but winters are chilly. There is moderate rainfall throughout the year. Pine and oak forests grow in this climate. "
The southeastern United States has a Mediterranean climate.,(A) true (B) false,B,"Moist subtropical mid-latitude climates are found along the coastal areas in the United States. Temperature: The coldest month ranges from just below freezing to almost balmy, between -3o C and 18o C (27o to 64o F). Summers are mild, with average temperatures above 10o C (50o F). Seasons are distinct. Rainfall: There is plentiful annual rainfall. "
"Subarctic climates have low precipitation, especially during the winter.",(A) true (B) false,A,"Polar climates are found near the North and South Poles. They also occur on high mountains at lower latitudes. The summers are very cool, and the winters are frigid. Precipitation is very low because its so cold. You can see examples of polar climates in Figure 17.14. Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate. Alpine tundra climates occur at high altitudes at any latitude. They are also called highland climates. These regions are very cold because they are so far above sea level. The alpine tundra climate is very similar to the polar tundra climate. Ice caps are areas covered with thick ice year round. Ice caps are found only in Greenland and Antarctica. Temperatures and precipitation are both very low. What little snow falls usually stays on the ground. It doesnt melt because its too cold. "
"Ice caps are found in Alaska, Canada, and Greenland.",(A) true (B) false,B,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
Tundra climates occur only near the poles.,(A) true (B) false,B,"Polar climates are found near the North and South Poles. They also occur on high mountains at lower latitudes. The summers are very cool, and the winters are frigid. Precipitation is very low because its so cold. You can see examples of polar climates in Figure 17.14. Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate. Alpine tundra climates occur at high altitudes at any latitude. They are also called highland climates. These regions are very cold because they are so far above sea level. The alpine tundra climate is very similar to the polar tundra climate. Ice caps are areas covered with thick ice year round. Ice caps are found only in Greenland and Antarctica. Temperatures and precipitation are both very low. What little snow falls usually stays on the ground. It doesnt melt because its too cold. "
Continental climates include humid continental and humid subtropical climates.,(A) true (B) false,B,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
Which of the following is a major climate type?,(A) desert (B) steppe (C) temperate climate (D) Mediterranean climate,C,"The Kppen classification system recognizes five major climate groups. Each group is divided into subcategories. Some of these subcategories are forest, monsoon, and wet/dry types, based on the amount of precipitation and season when that precipitation occurs (Figure 1.1). This world map of the Kppen classification system indicates where the climate zones and major biomes are located. "
Which climate type occurs between 5 and 20 degrees latitude?,(A) tropical wet and dry climate (B) humid subtropical climate (C) marine west coast climate (D) tropical wet climate,A,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
Arid climates are dry because they have,(A) low rates of precipitation (B) high rates of evaporation (C) high rates of condensation (D) two of the above,D,"Dry climates receive very little rainfall. They also have high rates of evaporation. This makes them even drier. The driest climates are deserts. Most occur between about 15 and 30 latitude. This is where dry air sinks to the surface in the global circulation cells. Deserts receive less than 25 centimeters (10 inches) of rain per year. They may be covered with sand dunes or be home to sparse but hardy plants (see Figure 17.11). With few clouds, deserts have hot days and cool nights. Other dry climates get a little more precipitation. They are called steppes. These regions have short grasses and low bushes (see Figure 17.11). Steppes occur at higher latitudes than deserts. They are dry because they are in continental interiors or rain shadows. "
Which type of climate is found on the western coasts of continents between 45 and 60 degrees latitude?,(A) Mediterranean climate (B) marine west coast climate (C) humid subtropical climate (D) humid continental climate,B,"Temperate climates have moderate temperatures. These climates vary in how much rain they get and when the rain falls. You can see different types of temperate climates in Figure 17.12. Mediterranean climates are found on the western coasts of continents. The latitudes are between 30 and 45. The coast of California has a Mediterranean climate. Temperatures are mild and rainfall is moderate. Most of the rain falls in the winter, and summers are dry. To make it through the dry summers, short woody plants are common. Marine west coast climates are also found on the western coasts of continents. They occur between 45 and 60 latitude. The coast of Washington State has this type of climate. Temperatures are mild and theres plenty of rainfall all year round. Dense fir forests grow in this climate. Humid subtropical climates are found on the eastern sides of continents between about 20 and 40 latitude. The southeastern U.S. has this type of climate. Summers are hot and humid, but winters are chilly. There is moderate rainfall throughout the year. Pine and oak forests grow in this climate. "
A humid subtropical climate is characterized by,(A) hot summers (B) warm winters (C) wet summers and dry winters (D) two of the above,A,"Tropical moist climates are found in a band about 15o to 25o N and S of the Equator (Figure 1.1). Temperature: Intense sunshine. Each month has an average temperature of at least 18o C (64o F). Rainfall: Abundant, at least 150 cm (59 inches) per year. The main vegetation for this climate is the tropical rainforest. "
Which type of forests grow in a humid continental climate?,(A) rainforests (B) pine forests (C) conifer forests (D) deciduous forests,D,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
Which climate is most similar to a polar tundra climate?,(A) highland climate (B) subarctic climate (C) semiarid climate (D) continental climate,A,"Polar climates are found near the North and South Poles. They also occur on high mountains at lower latitudes. The summers are very cool, and the winters are frigid. Precipitation is very low because its so cold. You can see examples of polar climates in Figure 17.14. Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate. Alpine tundra climates occur at high altitudes at any latitude. They are also called highland climates. These regions are very cold because they are so far above sea level. The alpine tundra climate is very similar to the polar tundra climate. Ice caps are areas covered with thick ice year round. Ice caps are found only in Greenland and Antarctica. Temperatures and precipitation are both very low. What little snow falls usually stays on the ground. It doesnt melt because its too cold. "
Which of the following statements about climate change is false?,(A) Earths climate has changed many times in the past (B) Earths climate has been hotter than it is today (C) Earths climate has been colder than it is today (D) Earths climate has never changed before now,D,"The theory of climate change is a much newer theory than the previous two. We know that average global tempera- tures are rising. We even know why: Carbon dioxide is released into the atmosphere when fossil fuels are burned. Carbon dioxide is a greenhouse gas. In the atmosphere, greenhouse gases trap heat. This is like putting an extra blanket over Earth. Since more heat is being trapped, global temperature is rising. There is very little information that contradicts the theory that climate is changing due in large part to human activities. Unless some major discrepancy is discovered about how the atmosphere works, the theory is very likely to stand. So far, the evidence that is being collected supports the idea and global warming can be used to predict future events, which are already taking place. This idea will be explored in detail in later concepts. "
How much have temperatures risen since the end of the Pleistocene ice ages?,(A) -4 C (B) 0 C (C) 4 C (D) 40 C,C,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
The 14 hottest years on record have all occurred since,(A) 1900 (B) 1990 (C) 1995 (D) 1998,A,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
Atmospheric greenhouse gas levels,(A) are currently falling (B) are currently stable (C) are not being measured (D) are currently rising,D,Human activity has significantly raised the levels of many of greenhouse gases in the atmosphere. Methane levels are about 2 1/2 times higher as a result of human activity. Carbon dioxide has increased more than 35%. CFCs have only recently existed. What do you think happens as atmospheric greenhouse gas levels increase? More greenhouse gases trap more heat and warm the atmosphere. The increase or decrease of greenhouse gases in the atmosphere affect climate and weather the world over. Click image to the left or use the URL below. URL: 
Natural processes that may have affected Earths temperature in the past include a ##change in the tilt of Earths axis.,(A) large asteroid striking Earth (B) huge volcanic eruption (C) all of the above,D,"Several natural processes may affect Earths temperature. They range from sunspots to Earths wobble. Sunspots are storms on the Sun. When the number of sunspots is high, the Sun gives off more energy than usual. Still, there is little evidence for climate changing along with the sunspot cycle. Plate movements cause continents to drift closer to the poles or the equator. Ocean currents also shift when continents drift. All these changes can affect Earths temperature. Plate movements trigger volcanoes. A huge eruption could spew so much gas and ash into the air that little sunlight would reach the surface for months or years. This could lower Earths temperature. A large asteroid hitting Earth would throw a lot of dust into the air. This could block sunlight and cool the planet. Earth goes through regular changes in its position relative to the Sun. Its orbit changes slightly. Earth also wobbles on its axis of rotation. The planet also changes the tilt on its axis. These changes can affect Earths temperature. "
Sunspots,(A) are storms on the Suns surface (B) change in number over time (C) have not been found to be the cause of global warming (D) all of these,D,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
"Burning fossil fuels,",(A) increases the ozone content of the atmosphere (B) releases carbon dioxide into the atmosphere (C) create an ozone hole that destroy the ozone layer (D) none of these,B,"Burning fossil fuels releases many pollutants into the air. These pollutants include carbon monoxide, carbon dioxide, nitrogen dioxide, and sulfur dioxide. Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum. Power plants and factories account for more than a quarter of fossil fuel use. Power plants burn fossil fuels to generate electricity. Factories burn fossil fuels to power machines. Homes and other buildings also burn fossil fuels. The energy they release is used for heating, cooking, and other purposes. "
Recent global warming is due mainly to,(A) plate tectonics (B) sunspot activity (C) human actions (D) none of the above,C,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
Effects of global warming include all of the following except,(A) sea ice melting (B) coral reefs dying out (C) more extreme weather (D) fewer short-term climate changes,D,"The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: "
An El Nio event,(A) shuts down upwelling off of South America (B) changes water temperature (C) affects worldwide weather for as long as two years (D) all of these,D,"In an El Nio year, when water temperature reaches around 28o C (82o F), the trade winds weaken or reverse direction and blow east (toward South America) (Figure 1.2). Warm water is dragged back across the Pacific Ocean and piles up off the west coast of South America. With warm, low-density water at the surface, upwelling stops. Without upwelling, nutrients are scarce and plankton populations decline. Since plankton form the base of the food web, fish cannot find food, and fish numbers decrease as well. All the animals that eat fish, including birds and humans, are affected by the decline in fish. By altering atmospheric and oceanic circulation, El Nio events change global climate patterns. Some regions receive more than average rainfall, including the west coast of North and South America, the southern United States, and Western Europe. Drought occurs in other parts of South America, the western Pacific, southern and northern Africa, and southern Europe. An El Nio cycle lasts one to two years. Often, normal circulation patterns resume. Sometimes circulation patterns bounce back quickly and extremely (Figure 1.3). This is a La Nia. "
What happens during El Nio?,(A) The trade winds change direction (B) The Pacific Ocean cools off more than usual (C) Upwelling occurs off the west coast of South America (D) Warm water travels from northeast to southwest across the Pacific Ocean,A,"In an El Nio year, when water temperature reaches around 28o C (82o F), the trade winds weaken or reverse direction and blow east (toward South America) (Figure 1.2). Warm water is dragged back across the Pacific Ocean and piles up off the west coast of South America. With warm, low-density water at the surface, upwelling stops. Without upwelling, nutrients are scarce and plankton populations decline. Since plankton form the base of the food web, fish cannot find food, and fish numbers decrease as well. All the animals that eat fish, including birds and humans, are affected by the decline in fish. By altering atmospheric and oceanic circulation, El Nio events change global climate patterns. Some regions receive more than average rainfall, including the west coast of North and South America, the southern United States, and Western Europe. Drought occurs in other parts of South America, the western Pacific, southern and northern Africa, and southern Europe. An El Nio cycle lasts one to two years. Often, normal circulation patterns resume. Sometimes circulation patterns bounce back quickly and extremely (Figure 1.3). This is a La Nia. "
La Nia occurs,(A) when the Pacific Ocean is warmer than normal (B) because the trade winds change direction (C) only in the Atlantic Ocean (D) following El Nio,D,La Nia generally follows El Nio. It occurs when the Pacific Ocean is cooler than normal. Figure 17.26 shows what happens. The trade winds are like they are in a normal year. They blow from east to west. But in a La Nia the winds are stronger than usual. More cool water builds up in the western Pacific. These changes can also affect climates worldwide. 
Small changes in temperature can make big changes in climate.,(A) true (B) false,A,"When a place is near an ocean, the water can have a big effect on the climate. "
From O C.E. to 2010 C.E. average global temperature has gone straight up.,(A) true (B) false,B,"While temperatures have risen since the end of the Pleistocene, 10,000 years ago, this rate of increase has been more rapid in the past century, and has risen even faster since 1990. The 10 warmest years in the 134-year record have all occurred since in the 21st century, and only one year during the 20th century (1998) was warmer than 2013, the 4th warmest year on record (through 2013) (Figure 1.1). The 2000s were the warmest decade yet. Annual variations aside, the average global temperature increased about 0.8o C (1.5o F) between 1880 and 2010, according to the Goddard Institute for Space Studies, NOAA. This number doesnt seem very large. Why is it important? "
Climate can change as continents shift position.,(A) true (B) false,A,"Plate tectonic movements can alter climate. Over millions of years as seas open and close, ocean currents may distribute heat differently. For example, when all the continents are joined into one supercontinent (such as Pangaea), nearly all locations experience a continental climate. When the continents separate, heat is more evenly distributed. Plate tectonic movements may help start an ice age. When continents are located near the poles, ice can accumulate, which may increase albedo and lower global temperature. Low enough temperatures may start a global ice age. Plate motions trigger volcanic eruptions, which release dust and CO2 into the atmosphere. Ordinary eruptions, even large ones, have only a short-term effect on weather (Figure 1.2). Massive eruptions of the fluid lavas that create lava plateaus release much more gas and dust, and can change climate for many years. This type of eruption is exceedingly rare; none has occurred since humans have lived on Earth. "
Global warming will cause weather to be more extreme.,(A) true (B) false,A,"Global warming will change patterns of rainfall and water distribution. As the Earth warms, regions that currently receive an adequate supply of rain may shift. Regions that rely on snowmelt may find that there is less snow and the melt comes earlier and faster in the spring, causing the water to run off and not be available through the dry summers. A change in temperature and precipitation would completely change the types of plants and animals that can live successfully in that region. "
All global warming projections show temperature rising during this century.,(A) true (B) false,A,"With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. "
It takes large changes in Earths climate to affect living things.,(A) true (B) false,B,"When a place is near an ocean, the water can have a big effect on the climate. "
Only one ice age occurred over the past billion years.,(A) true (B) false,B,"The last major ice age took place in the Pleistocene. This epoch lasted from 2 million to 14,000 years ago. Earths temperature was only 5 C (9 F) cooler than it is today. But glaciers covered much of the Northern Hemisphere. In Figure 17.17, you can see how far south they went. Clearly, a small change in temperature can have a big impact on the planet. Humans lived during this ice age. "
"In the Pleistocene ice age, Earths temperature was 5 C cooler than it is today.",(A) true (B) false,A,"The last major ice age took place in the Pleistocene. This epoch lasted from 2 million to 14,000 years ago. Earths temperature was only 5 C (9 F) cooler than it is today. But glaciers covered much of the Northern Hemisphere. In Figure 17.17, you can see how far south they went. Clearly, a small change in temperature can have a big impact on the planet. Humans lived during this ice age. "
"During the last ice age, glaciers covered much of North America.",(A) true (B) false,A,"During the Quaternary Period, the climate cooled. This caused a series of ice ages. Glaciers advanced southward from the North Pole. They reached as far south as Chicago and New York City. Sea levels fell because so much water was frozen in glaciers. This exposed land bridges between continents. The land bridges allowed land animals to move to new areas. Some mammals adapted to the cold by evolving very large size and thick fur. An example is the woolly mammoth, shown in Figure 7.25. Other mammals moved closer to the equator. Those that couldnt adapt or move went extinct, along with many plants. The last ice age ended about 12,000 years ago. By then, our own species, Homo sapiens, had evolved. After that, we were eyewitnesses to the story of life. As a result, the recent past is less of a mystery than the billions of years before it. "
Temperatures were higher during the Medieval warm period than they have been over the past decade.,(A) true (B) false,B,"While temperatures have risen since the end of the Pleistocene, 10,000 years ago, this rate of increase has been more rapid in the past century, and has risen even faster since 1990. The 10 warmest years in the 134-year record have all occurred since in the 21st century, and only one year during the 20th century (1998) was warmer than 2013, the 4th warmest year on record (through 2013) (Figure 1.1). The 2000s were the warmest decade yet. Annual variations aside, the average global temperature increased about 0.8o C (1.5o F) between 1880 and 2010, according to the Goddard Institute for Space Studies, NOAA. This number doesnt seem very large. Why is it important? "
Plate tectonics may cause ocean currents to shift.,(A) true (B) false,A,"Plate tectonic movements can alter climate. Over millions of years as seas open and close, ocean currents may distribute heat differently. For example, when all the continents are joined into one supercontinent (such as Pangaea), nearly all locations experience a continental climate. When the continents separate, heat is more evenly distributed. Plate tectonic movements may help start an ice age. When continents are located near the poles, ice can accumulate, which may increase albedo and lower global temperature. Low enough temperatures may start a global ice age. Plate motions trigger volcanic eruptions, which release dust and CO2 into the atmosphere. Ordinary eruptions, even large ones, have only a short-term effect on weather (Figure 1.2). Massive eruptions of the fluid lavas that create lava plateaus release much more gas and dust, and can change climate for many years. This type of eruption is exceedingly rare; none has occurred since humans have lived on Earth. "
An enormous volcanic eruption would increase Earths temperature.,(A) true (B) false,B,"A supervolcano could change life on Earth as we know it. Ash could block sunlight so much that photosynthesis would be reduced and global temperatures would plummet. Volcanic eruptions could have contributed to some of the mass extinctions in our planets history. No one knows when the next super eruption will be. Interesting volcano videos are seen on National Geographic Videos, Environment Video, Natural Disasters, Earth- quakes: One interesting one is Mammoth Mountain, which explores Hot Creek and the volcanic area it is a part of in California. Click image to the left or use the URL below. URL: "
Solar storms are the main cause of recent global warming.,(A) true (B) false,B,Natural processes caused earlier climate changes. Human beings are the main cause of recent global warming. 
Greenhouse gases block sunlight and cool the planet.,(A) true (B) false,B,"When sunlight heats Earths surface, some of the heat radiates back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere. This is the greenhouse effect, and it helps to keep Earth warm. The greenhouse effect allows Earth to have temperatures that can support life. Gases that absorb heat in the atmosphere are called greenhouse gases. They include carbon dioxide and water vapor. Human actions have increased the levels of greenhouse gases in the atmosphere. This is shown in Figure 15.11. The added gases have caused a greater greenhouse effect. How do you think this affects Earths temperature? "
The amount of carbon dioxide in the air has been increasing for many decades.,(A) true (B) false,A,"Atmospheric CO2 has increased over the past five decades, because the amount of CO2 gas released by volcanoes has increased. "
dramatic increase in Earths temperature since the middle of the 1800s,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,D,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
short-term climate change in which the Pacific Ocean is warmer than usual,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,E,"In a La Nia year, as in a normal year, trade winds moves from east to west and warm water piles up in the western Pacific Ocean. Ocean temperatures along coastal South America are colder than normal (instead of warmer, as in El Nio). Cold water reaches farther into the western Pacific than normal. Other important oscillations are smaller and have a local, rather than global, effect. The North Atlantic Oscillation mostly alters climate in Europe. The Mediterranean also goes through cycles, varying between being dry at some times and warm and wet at others. Click image to the left or use the URL below. URL: "
slight increase in Earths temperature that occurred about 1000 years ago,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,A,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
period in Earths history when temperatures were cooler than normal,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,C,"Over much of Earths past, the climate was warmer than it is today. Picture in your mind dinosaurs roaming the land. Theyre probably doing it in a pretty warm climate! But ice ages also occurred many times in the past. An ice age is a period when temperatures are cooler than normal. This causes glaciers to spread to lower latitudes. Scientists think that ice ages occurred at least six times over the last billion years alone. How do scientists learn about Earths past climates? "
movement of cold water from the bottom to the surface of the ocean,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,F,"Changes in temperature and salinity of seawater take place at the surface. Water becomes dense near the poles. Cold polar air cools the water and lowers its temperature, increasing its salinity. Fresh water freezes out of seawater to become sea ice, which also increases the salinity of the remaining water. This very cold, very saline water is very dense and sinks. This sinking is called downwelling. This video lecture discusses the vertical distribution of life in the oceans. Seawater density creates currents, which provide different habitats for different creatures: Click image to the left or use the URL below. URL:  Two things then happen. The dense water pushes deeper water out of its way and that water moves along the bottom of the ocean. This deep water mixes with less dense water as it flows. Surface currents move water into the space vacated at the surface where the dense water sank (Figure 1.1). Water also sinks into the deep ocean off of Antarctica. Cold water (blue lines) sinks in the North Atlantic, flows along the bottom of the ocean and upwells in the Pacific or Indian. The water then travels in surface currents (red lines) back to the North Atlantic. Deep water also forms off of Antarctica. "
difference from average temperature,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,G,"Its easy to see the difference in temperature at different latitudes in the Figure 1.1. But temperature is not completely correlated with latitude. There are many exceptions. For example, notice that the western portion of South America The maximum annual temperature of the Earth, showing a roughly gradual temperature gradient from the low to the high latitudes. has relatively low temperatures due to the Andes Mountains. The Rocky Mountains in the United States also have lower temperatures due to high altitudes. Western Europe is warmer than it should be due to the Gulf Stream. Click image to the left or use the URL below. URL: "
short-term climate change in which the Pacific Ocean is cooler than usual,(A) medieval warm period (B) La Nia (C) ice age (D) global warming (E) El Nio (F) upwelling (G) temperature anomaly,B,"In a La Nia year, as in a normal year, trade winds moves from east to west and warm water piles up in the western Pacific Ocean. Ocean temperatures along coastal South America are colder than normal (instead of warmer, as in El Nio). Cold water reaches farther into the western Pacific than normal. Other important oscillations are smaller and have a local, rather than global, effect. The North Atlantic Oscillation mostly alters climate in Europe. The Mediterranean also goes through cycles, varying between being dry at some times and warm and wet at others. Click image to the left or use the URL below. URL: "
process in which living things obtain energy from food,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,B,"Living things can be classified based on how they obtain energy. Some use the energy in sunlight or chemical compounds directly to make food. Some get energy indirectly by consuming other organisms, either living or dead. "
What happens during respiration?,(A) producers create food energy from solar energy (B) consumers use solar energy to create food energy (C) living things release energy from food (D) carbon dioxide is converted into oxygen,C,"The bodys exchange of oxygen and carbon dioxide with the air is called respiration. Respiration actually consists of two stages. In one stage, air is taken into the body and carbon dioxide is released to the outside air. In the other stage, oxygen is delivered to all the cells of the body and carbon dioxide is carried away from the cells. Another kind of respiration takes place within body cells. This kind of respiration is called cellular respiration. Its the process in which cells obtain energy by burning glucose. Both types of respiration are connected. Cellular respiration uses oxygen and produces carbon dioxide. Respiration by the respiratory system supplies the oxygen needed for cellular respiration. It also removes the carbon dioxide produced by cellular respiration. "
carbon compound used by plants to make sugar,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,G,Producers such as plants or algae use carbon dioxide in the air to make food. The organisms combine carbon dioxide with water to make sugar. They store the sugar as starch. Both sugar and starch are carbohydrates. Consumers get carbon when they eat producers or other consumers. Carbon doesnt stop there. Living things get energy from food in a process called respiration. This releases carbon dioxide back into the atmosphere. The cycle then repeats. 
What is nitrogen fixing?,(A) Soil bacteria make nitrogen useful for producers (B) Producers make nitrogen useful for consumers (C) Nitrogen gas in the atmosphere creates complex compounds (D) Nitrogen combines with oxygen to make a useful gas,A,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
key element in proteins,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,E,"Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. "
Greenhouse gases,(A) absorb incoming solar radiation in the atmosphere (B) trap infrared radiation radiating from Earths surface (C) scatter sunlight from one molecule to another (D) All of these,B,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
Carbon is,(A) stored in the mantle (B) released into the atmosphere at volcanoes (C) stored in the oceans (D) all of these,D,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
process that releases nitrogen from organic remains,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,D,"Animals eat plant tissue and create animal tissue. After a plant or animal dies or an animal excretes waste, bacteria and some fungi in the soil fix the organic nitrogen and return it to the soil as ammonia. Nitrifying bacteria oxidize the ammonia to nitrites, while other bacteria oxidize the nitrites to nitrates, which can be used by the next generation of plants. In this way, nitrogen does not need to return to a gas. Under conditions when there is no oxygen, some bacteria can reduce nitrates to molecular nitrogen. Click image to the left or use the URL below. URL: "
process that changes nitrogen to a form that plants can use,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,F,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
Destroying forests changes the carbon cycle because,(A) plants take carbon out of the atmosphere (B) burning plants releases stored carbon into the atmosphere (C) more carbon is in the atmosphere (D) all of these,D,"Human actions are influencing the carbon cycle. Burning of fossil fuels releases the carbon dioxide that was stored in ancient plants. Carbon dioxide is a greenhouse gas and is a cause of global warming. Forests are also being destroyed. Trees may be cut down for their wood, or they may be burned to clear the land for farming. Burning wood releases more carbon dioxide into the atmosphere. You can see how a tropical rainforest was cleared for farming in Figure 18.12. With forests shrinking, there are fewer trees to remove carbon dioxide from the air. This makes the greenhouse effect even worse. "
element that is the basis of all life on Earth,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,C,"The element carbon is the basis of all life on Earth. Biochemical compounds consist of chains of carbon atoms and just a few other elements. Like water, carbon is constantly recycled through the biotic and abiotic factors of ecosystems. The carbon cycle includes carbon in sedimentary rocks and fossil fuels under the ground, the ocean, the atmosphere, and living things. The diagram in Figure 24.9 represents the carbon cycle. It shows some of the ways that carbon moves between the different parts of the cycle. You can see an animated carbon cycle at this link: http://commons.w "
type of carbon compound that includes sugars and starches,(A) carbohydrate (B) respiration (C) carbon (D) decomposition (E) nitrogen (F) nitrogen fixing (G) carbon dioxide,A,"Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. "
Carbon is an important part of organic material.,(A) true (B) false,A,"Carbon is a very important element to living things. As the second most common element in the human body, we know that human life without carbon would not be possible. Protein, carbohydrates, and fats are all part of the body and all contain carbon. When your body breaks down food to produce energy, you break down protein, carbohydrates, and fat, and you breathe out carbon dioxide. Carbon occurs in many forms on Earth. The element moves through organisms and then returns to the environment. When all this happens in balance, the ecosystem remains in balance too. "
"When an organism decomposes, its carbon is released back into the environment.",(A) true (B) false,A,"Major exchange pools of carbon include organisms and the atmosphere. Carbon cycles more quickly between these components of the carbon cycle. Photosynthesis by plants and other producers removes carbon dioxide from the atmosphere to make organic compounds for living things. Cellular respiration by living things releases carbon into the atmosphere or ocean as carbon dioxide. Decomposition of dead organisms and organic wastes releases carbon back to the atmosphere, soil, or ocean. "
Carbon is only found in organic material.,(A) true (B) false,B,"A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. "
Nitrogen is a nutrient so more is always better.,(A) true (B) false,B,"Nitrogen (N2 ) is vital for life on Earth as an essential component of organic materials, such as amino acids, chloro- phyll, and nucleic acids such as DNA and RNA (Figure 1.1). Chlorophyll molecules, essential for photosynthesis, contain nitrogen. "
Algae create food energy from sunlight.,(A) true (B) false,A,"Photosynthetic bacteria use the energy of the sun to make their own food. In the presence of sunlight, carbon dioxide and water are turned into glucose and oxygen. The glucose is then turned into usable energy. Glucose is like the ""food"" for the bacteria. An example of photosynthetic bacteria is cyanobacteria, as seen in the opening image. These bacteria are sometimes called blue-green algae, although they are not algae, due to their numerous chlorophyll molecules. "
Carbon dioxide enters the atmosphere during,(A) photosynthesis (B) burning (C) decay (D) all of the above,B,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
Which of the following compounds in living things contain carbon?,(A) sugars (B) starches (C) proteins (D) all of the above,D,"Besides water, most of the compounds in living things are biochemical compounds. A biochemical compound is a carbon-based compound that is found in living organisms. Carbon is an element that has a tremendous ability to form large compounds. Each atom of carbon can form four chemical bonds with other atoms. A chemical bond is the sharing of electrons between atoms. Bonds hold the atoms together in chemical compounds. A carbon atom can form bonds with other carbon atoms or with atoms of other elements. "
Consumers get carbon by,(A) photosynthesis (B) respiration (C) breathing (D) eating,D,Producers such as plants or algae use carbon dioxide in the air to make food. The organisms combine carbon dioxide with water to make sugar. They store the sugar as starch. Both sugar and starch are carbohydrates. Consumers get carbon when they eat producers or other consumers. Carbon doesnt stop there. Living things get energy from food in a process called respiration. This releases carbon dioxide back into the atmosphere. The cycle then repeats. 
Human beings affect the carbon cycle by,(A) burning wood (B) using fossil fuels (C) cutting down forests (D) all of the above,D,"Human actions are influencing the carbon cycle. Burning of fossil fuels releases the carbon dioxide that was stored in ancient plants. Carbon dioxide is a greenhouse gas and is a cause of global warming. Forests are also being destroyed. Trees may be cut down for their wood, or they may be burned to clear the land for farming. Burning wood releases more carbon dioxide into the atmosphere. You can see how a tropical rainforest was cleared for farming in Figure 18.12. With forests shrinking, there are fewer trees to remove carbon dioxide from the air. This makes the greenhouse effect even worse. "
Which process releases nitrogen into the air?,(A) breaking down waste (B) fixing nitrogen (C) using fertilizer (D) making sugar,A,"Turning nitrate back into nitrogen gas, the process of denitrification, happens through the work of denitrifying bacteria. These bacteria often live in swamps and lakes. They take in the nitrate and release it back to the atmosphere as nitrogen gas. Just like the carbon cycle, human activities impact the nitrogen cycle. These human activities include the burning of fossil fuels, which release nitrogen oxide gasses into the atmosphere. Releasing nitrogen oxide back into the atmosphere leads to problems like acid rain. "
"Without certain organisms that live in soil, plants would not be able to use",(A) carbon (B) oxygen (C) nitrogen (D) carbon dioxide,C,"Soil is an ecosystem unto itself. In the spaces of soil, there are thousands or even millions of living organisms. Those organisms could include earthworms, ants, bacteria, or fungi (Figure 1.4). "
The underlying cause of dead zones is,(A) not enough carbon in the water (B) too much nitrogen in the water (C) too few organisms in the water (D) none of the above,B,"Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. Every year dead zones appear in lakes and nearshore waters. A dead zone is an area of hundreds of kilometers of ocean without fish or plant life. The Mississippi is not the only river that carries the nutrients necessary to cause a dead zone. Rivers that drain regions where human population density is high and where crops are grown create dead zones all over the world (Figure 1.2). "
The carbon cycle includes both living and nonliving things.,(A) true (B) false,A,"In the carbon cycle, carbon moves through living and nonliving things. Carbon actually moves through two cycles that overlap. One cycle is mainly biotic; the other cycle is mainly abiotic. Both cycles are shown in Figure 18.11. "
Carbon changes form as it moves through the carbon cycle.,(A) true (B) false,A,"In the carbon cycle, carbon moves through living and nonliving things. Carbon actually moves through two cycles that overlap. One cycle is mainly biotic; the other cycle is mainly abiotic. Both cycles are shown in Figure 18.11. "
Volcanic eruptions release carbon dioxide into the air.,(A) true (B) false,A,"Atmospheric CO2 has increased over the past five decades, because the amount of CO2 gas released by volcanoes has increased. "
The atmosphere contains more carbon than the oceans.,(A) true (B) false,B,"Oceans are the major source of water vapor in the atmosphere. Sunlight heats water near the sea surface, as shown in Figure 14.3. As the water warms, some of it evaporates. The water vapor rises into the air, where it may form clouds and precipitation. Precipitation provides the freshwater needed by plants and other living things. Ocean water also absorbs gases from the atmosphere. The most important are oxygen and carbon dioxide. Oxygen is needed by living things in the oceans. Much of the carbon dioxide sinks to the bottom of the seas. Carbon dioxide is a major cause of global warming. By absorbing carbon dioxide, the oceans help control global warming. "
Carbon cycles very quickly through ocean water.,(A) true (B) false,B,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
Nitrogen is one of the most important nutrients needed by plants.,(A) true (B) false,A,"Nitrogen (N2 ) is vital for life on Earth as an essential component of organic materials, such as amino acids, chloro- phyll, and nucleic acids such as DNA and RNA (Figure 1.1). Chlorophyll molecules, essential for photosynthesis, contain nitrogen. "
Plants obtain nitrogen directly from the atmosphere.,(A) true (B) false,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
Nitrogen in runoff that enters ponds kills algae and water plants.,(A) true (B) false,B,"Nitrogen is one of the most important nutrients needed by plants. Thats why most plant fertilizers contain nitrogen. Adding fertilizer to soil allows more plants to grow. As a result, a given amount of land can produce more food. So far, so good. But what happens next? Rain dissolves fertilizer in the soil. Runoff carries it away. The fertilizer ends up in bodies of water, from ponds to oceans. The nitrogen is a fertilizer in the water bodies. Since there is a lot of nitrogen it causes algae to grow out of control. Figure 18.14 shows a pond covered with algae. Algae may use up so much oxygen in the water that nothing else can grow. Soon, even the algae die out. Decomposers break down the dead tissue and use up all the oxygen in the water. This creates a dead zone. A dead zone is an area in a body of water where nothing grows because there is too little oxygen. There is a large dead zone in the Gulf of Mexico. You can see it Figure 18.14. "
"When algae use food for energy, they release oxygen into the water.",(A) true (B) false,B,"In a marine ecosystem, algae are the producers. Through photosynthesis, they provide glucose for the ecosystem. So, can too much algae be a bad thing? Eutrophication is an over-enrichment of chemical nutrients in a body of water. Usually these nutrients are the nitrogen and phosphorous found in fertilizers. Run-off from lawns or farms can wash fertilizers into rivers or coastal waters. Plants are not the only things that grow more quickly with added fertilizers. Algae like the excess nutrients in fertilizers too. When there are high levels of nutrients in the water, algae populations will grow large very quickly. This leads to overgrowths of algae called algal blooms. However, these algae do not live very long. They die and begin to decompose. This process uses oxygen, removing the oxygen from the water. Without oxygen, fish and shellfish cannot live, and this results in the death of these organisms ( Figure 1.1). Certain types of algal blooms can also create toxins. These toxins can enter shellfish. If humans eat these shellfish, then they can get very sick. These toxins cause neurological problems in humans. "
There is a large dead zone in the Gulf of Mexico.,(A) true (B) false,A,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
The population growth rate equals the number of births in a year per 100 people.,(A) true (B) false,B,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
"If the birth rate is less than the death rate, then the population has a growth rate of zero.",(A) true (B) false,B,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
There is no limit on how large a population can grow.,(A) true (B) false,B,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
The human population started to grow rapidly in the 1800s.,(A) true (B) false,A,"Figure 18.17 shows how the human population has grown. It grew very slowly for tens of thousands of years. Then, in the 1800s, something happened to change all that. The human population started to grow much faster. "
"In the first phase of the demographic transition, populations grew slowly.",(A) true (B) false,B,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
Pesticides increase crop production by killing weed plants.,(A) true (B) false,B,"Chemical control of pests involves the use of insecticides. Insecticides, which are also known as pesticides, are most often used to kill insects. Insecticides are chemicals that kill insects. The U.S. spends $9 billion each year on pesticides. Disadvantages to using pesticides include human, fish, and honeybee poisonings, and the contamination of meat and dairy products. When choosing to use an insecticide, there are numerous points to consider. Negative effects of the pesticide should try to be minimized. Important questions to consider include the following. What is the chemicals success against the target pest? Will the insecticide provide the desired level of control of the pest? If the answer is no, other methods of control should be considered. Does the chemical have an impact on natural enemies of the pest? In large scale efforts to rid areas of mosquitoes, the insecticide used also killed the dragonfly. This effort removed a natural predator of the mosquito. This may be an unacceptable negative effect of using the insecticide. How susceptible is the crop to insect damage? If the crop is not heavily damaged, only minor pest control may be needed. This may affect the amount or type of insecticide used. How toxic is the chemical to the environment and humans? Some older insecticides are extremely poisonous. Keep in mind that users of these poisons have a community responsibility to minimize the contamination of the surrounding environment, as well as keeping animals, surrounding crops and humans safe. Does using the pesticide result in the development of resistance? If so, this can make additional use of the pesticide less effective. As the resistance will be passed to future generations of the insect (which is natural selection in action), this could be considered a negative side-effect of pesticide use. "
Human population growth rates are highest in the United States.,(A) true (B) false,B,"On the other hand, if you look at human population growth in specific countries, you may see a different pattern. On the level of a country, the history of human population growth can be divided into five stages, as described in Table 1.1. Some countries have very high birth rates, in some countries the growth rate has stabilized, and in some countries the growth rate is in decline. Stage 1 2 3 4 5 Description Birth and death rates are high and population growth is stable. This occurred in early human history. Significant drop in death rate, resulting in exponential growth. This occurred in 18th- and 19th-century Eu- rope. Population size continues to grow. Birth rates equal death rates and populations become stable. Total population size may level off. The United Nations and the U.S. Census Bureau predict that by 2050, the Earth will be populated by 9.4 billion people. Other estimates predict 10 to 11 billion. "
We may run out of oil by the mid-2000s.,(A) true (B) false,A,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
Alien species can cause native species to go extinct.,(A) true (B) false,A,"One of the main causes of extinction is introduction of exotic species into an environment. These exotic and new species can also be called invasive species or non-native species. These non-native species, being new to an area, may not have natural predators in the new habitat, which allows their populations to easily adapt and grow. Invasive species out-compete the native species for resources. Sometimes invasive species are so successful at living in a certain habitat that the native species go extinct ( Figure 1.4). Recently, cargo ships have transported zebra mussels, spiny waterfleas, and ruffe (a freshwater fish) into the Great Lakes ( Figure 1.5). These invasive species are better at hunting for food. They have caused some of the native species to go extinct. Invasive species can disrupt food chains, carry disease, prey on native species directly, and out-compete native species for limited resources, like food. All of these effects can lead to extinction of the native species. "
Some people think that sustainable development may require a smaller human population.,(A) true (B) false,A,"There are two different beliefs about what type of growth the human population will undergo in the future: 1. Neo-Malthusians believe that human population growth cannot continue without destroying the environment, and maybe humans themselves. 2. Cornucopians believe that the Earth can give humans a limitless amount of resources. They also believe that technology can solve problems caused by limited resources, such as lack of food. The Cornucopians believe that a larger population is good for technology and innovation. The 5-stage model above predicts that when all countries are industrialized, the human population will eventually level out. But many scientists and other Neo-Malthusians believe that humans have already gone over the Earths carrying capacity. That means, we may have already reached the maximum population size that can be supported, without destroying our resources and habitat. If this is true, then human overpopulation will lead to a lack of food and other resources. Overpopulation may also lead to increased disease, and/or war. These problems may cause the population of humans to crash. If these issues are not controlled, could the human population go extinct? Which of the above theories makes sense to you? Why? "
annual births minus deaths per 100 population members,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,D,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
drug that kills bacteria,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,F,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
using resources in a way that gives everyone enough and protects the environment,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,G,"Is it possible for all the worlds people to live well and still protect the planet? Thats the aim of sustainable development. Its goals are to: 1. Distribute resources fairly. 2. Conserve resources so they wont run out. 3. Use resources in ways that wont harm ecosystems. A smaller human population may be part of the solution. Better use of resources is another part. For example, when forests are logged, new trees should be planted. Everyone can help in the effort. What will you do? "
substance that prevents a disease,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,B,"Noninfectious diseases cant be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If youre born with these conditions, you must learn how to manage the symptoms. Examples of conditions caused by environmental or lifestyle factors include heart disease and skin cancer. We cant change our genetic codes, but there are plenty of ways to prevent other noninfectious diseases. For example, cutting down on exposure to cigarette smoke and the suns rays will prevent certain types of cancer. It is a fact that most chronic noninfectious diseases can be prevented. The chronic noninfectious diseases that cause the most deaths in many developed countries are largely preventable. These diseases are heart disease, stroke, diabetes and cancer, and though they do have some genetic components, they also have many lifestyle components. For example, some cancers have genetic risks, but people at high risk for cancers can have screening examinations to catch them early or sometimes can take other steps to prevent the cancers. Heart disease, stroke and diabetes are mostly linked to lifestyle choices, even when family history puts a person at higher risk for the diseases. Most allergies can be prevented by avoiding the substances that cause them. For example, you can avoid pollens by staying indoors as much as possible. You can learn to recognize plants like poison ivy and not touch them. A good way to remember how to avoid poison ivy is ""leaves of three, let it be."" Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens, which are the substances that cause an allergic reaction. After many months or years of shots, the immune system gets used to the allergens and no longer responds to them. Type 1 diabetes and other autoimmune diseases cannot be prevented. But choosing a healthy lifestyle can help prevent type 2 diabetes. Getting plenty of exercise, avoiding high-fat foods, and staying at a healthy weight can reduce the risk of developing this type of diabetes. This is especially important for people who have family members with the disease. Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens, which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure 1.1). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesnt matter whether the radiation comes from tanning lamps or the sun. Overall, people in many developed countries are contributing to higher rates of noninfectious diseases (heart disease, stroke, diabetes and cancer) by taking advantage of technology and social environments that encourage a less active lifestyle, and also encourages faster and cheaper meals. For example, many children now spend more time on their computer or watching TV then playing outdoors. The ""faster and cheaper"" meals are usually less healthy than other meals. Even though many people are living longer, they can choose to live more healthily by adopting regular exercise routines and healthy eating habits. When you choose a sunscreen, select one with an SPF (sun protection factor) of 30 or higher. Also, choose a sunscreen that protects against both UVB and UVA radiation. "
largest population that can be supported by the environment,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,C,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
change from high birth and death rates to low birth and death rates,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,E,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
increase in food production due to new products and methods,(A) green revolution (B) vaccine (C) carrying capacity (D) population growth rate (E) demographic transition (F) antibiotic (G) sustainable development,A,"The Green Revolution has allowed the addition of billions of people to the population in the past few decades. The Green Revolution has improved agricultural productivity by: Improving crops by selecting for traits that promote productivity; recently, genetically engineered crops have been introduced. Increasing the use of artificial fertilizers and chemical pesticides. About 23 times more fertilizer and 50 times more pesticides are used around the world than were used just 50 years ago (Figure 1.5). Agricultural machinery: plowing, tilling, fertilizing, picking, and transporting are all done by machines. About 17% of the energy used each year in the United States is for agriculture. Increasing access to water. Many farming regions depend on groundwater, which is not a renewable resource. Some regions will eventually run out of this water source. Currently about 70% of the worlds fresh water is used for agriculture. Rows of a single crop and heavy ma- chinery are normal sights for modern day farms. The Green Revolution has increased the productivity of farms immensely. A century ago, a single farmer produced enough food for 2.5 people, but now a farmer can feed more than 130 people. The Green Revolution is credited for feeding 1 billion people that would not otherwise have been able to live. "
About how many people live on Earth?,(A) 7 million (B) 7 billion (C) 9 billion (D) 7 trillion,B,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
"If the birth rate is greater than the death rate, then",(A) d is negative (B) b is negative (C) r is positive (D) two of the above,C,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
"If a population reaches its carrying capacity, it is most likely to",(A) grow rapidly (B) stop growing (C) increase its size (D) increase its carrying capacity,B,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
Food production increased during the,(A) green revolution (B) demographic transition (C) industrial revolution (D) all of the above,D,"The next major stage in the growth of the human population was the Industrial Revolution, which started in the late 1700s (Figure 1.4). This major historical event marks when products were first mass-produced and when fossil fuels were first widely used for power. "
Human actions that lower death rates include,(A) improving sanitation (B) vaccinating children (C) purifying water (D) all of the above,D,"More recently, the death rate has fallen because of the availability of more food and medical advances: A green revolution began in the mid 1900s. New methods and products increased how much food could be grown. For example, chemicals were developed that killed weeds without harming crops. Pesticides were developed that killed pests that destroyed crops. Vaccinations were developed that could prevent many diseases (see Figure 18.19). Antibiotics were discov- ered that could cure most infections caused by bacteria. Together, these two advances saved countless lives. Today in many countries, death rates have gone down but birth rates remain high. This means that the population is growing. Figure 18.20 shows the growth rates of human populations all over the world. "
Some people think that the human population has reached its carrying capacity because,(A) we are saving the environment (B) everyone has just enough resources (C) we have enough fossil fuels for decades (D) none of the above,D,"The flip side to this is that for the population to continue to grow, more advances in agriculture and an ever increasing supply of water will be needed. Weve increased the carrying capacity for humans by our genius: growing crops, trading for needed materials, and designing ways to exploit resources that are difficult to get at, such as groundwater. And most of these resources are limited. The question is, even though we have increased the carrying capacity of the planet, have we now exceeded it (Figure There is not yet an answer to that question, but there are many different opinions. In the eighteenth century, Thomas Malthus predicted that human population would continue to grow until we had exhausted our resources. At that point, humans would become victims of famine, disease, or war. This has not happened, at least not yet. Some scientists think that the carrying capacity of the planet is about 1 billion people, not the 7 billion people we have today. The limiting factors have changed as our intelligence has allowed us to expand our population. Can we continue to do this indefinitely into the future? "
Goals of sustainable development include,(A) conserving resources (B) distributing resources fairly (C) using resources in ways that do not harm ecosystems (D) all of the above,D,"Is it possible for all the worlds people to live well and still protect the planet? Thats the aim of sustainable development. Its goals are to: 1. Distribute resources fairly. 2. Conserve resources so they wont run out. 3. Use resources in ways that wont harm ecosystems. A smaller human population may be part of the solution. Better use of resources is another part. For example, when forests are logged, new trees should be planted. Everyone can help in the effort. What will you do? "
Love Canal is considered to be one of the worst environmental disasters of all time.,(A) true (B) false,A,Love Canal gained worldwide attention in the late 1970s when the press started covering its story. The story is outlined below and illustrated in Figure 19.9. 
At Love Canal,(A) the hazardous wastes were safely buried (B) people became sick right after the town was built (C) the first sign that something was wrong was that children developed cancer (D) none of these,C,"The story of Love Canal, New York, begins in the 1950s, when a local chemical company placed hazardous wastes in 55-gallon steel drums and buried them. Love Canal was an abandoned waterway near Niagara Falls and was thought to be a safe site for hazardous waste disposal because the ground was fairly impermeable (Figure 1.1). After burial, the company covered the containers with soil and sold the land to the local school system for $1. The company warned the school district that the site had been used for toxic waste disposal. Steel drums were used to contain 21,000 tons of hazardous chemicals at Love Canal. Soon a school, a playground, and 100 homes were built on the site. The impermeable ground was breached when sewer systems were dug into the rock layer. Over time, the steel drums rusted and the chemicals were released into the ground. In the 1960s people began to notice bad odors. Children developed burns after playing in the soil, and they were often sick. In 1977 a swamp created by heavy rains was found to contain 82 toxic chemicals, including 11 suspected cancer-causing chemicals. A Love Canal resident, Lois Gibbs, organized a group of citizens called the Love Canal Homeowners Association to try to find out what was causing the problems (See opening image). When they discovered that toxic chemicals were buried beneath their homes and school, they demanded that the government take action to clean up the area and remove the chemicals. "
The soil of Love Canal was contaminated with lead and mercury.,(A) true (B) false,A,"The Love Canal disaster actually began back in the mid 1900s. The disaster continues even today. Starting in the early 1940s, a big chemical company put thousands of barrels of chemical waste into an old canal. Over the next 10 years, the company dumped almost 22,000 tons of chemicals into the ground! In the early 1950s, the company covered over the barrels in the canal with soil. Then they sold the land to the city for just a dollar. The city needed the land in order to build an elementary school. The company warned the city that toxic waste was buried there. But they thought the waste was safe. The school and hundreds of homes were also built over the old canal. As it turned out, the cheap price was no bargain. Chemicals started leaking from the barrels. Chemicals seeped into basements. Chemicals bubbled up to the surface of the ground. In some places, plants wouldnt even grow on the soil. People noticed bad smells. Many got sick, especially the children. Residents wanted to know if the old chemicals were the cause. But they had a hard time getting officials to listen. So they demonstrated and demanded answers. Finally, the soil was tested and was found to be contaminated with harmful chemicals. For example, it contained a lot of lead and mercury. Both can cause permanent damage to the human nervous system. The school was closed. More than 200 homes were evacuated. Much of the Love Canal neighborhood was bulldozed away. The area had a massive clean-up effort. The cleanup cost millions of dollars. More than three decades later, much of Love Canal is still too contaminated to be safe for people. "
Where are Superfund sites located?,(A) in densely populated areas (B) spread across the USA (C) East of the Mississippi River (D) all around the world,B,"Love Canal opened peoples eyes to toxic waste burial. They realized there must be other Love Canals all over the country. Thousands of contaminated sites were found. The Superfund Act was passed in 1980. The law required that money be set aside for cleanup of toxic waste sites, like the Elizabeth Copper Mine in Vermont (see the far-right image in Figure 19.9). The law also required safer disposal of hazardous waste in the future. "
Which of the following is NOT considered a potentially hazardous material?,(A) baking soda (B) batteries (C) fertilizers (D) paint,A,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
The Superfund Act requires safe disposal of hazardous waste.,(A) true (B) false,A,"Thanks to the lessons of Love Canal, the U.S. now has laws requiring the safe disposal of hazardous waste. Companies must ensure that hazardous waste is not allowed to enter the environment in dangerous amounts. They must also protect their workers from hazardous materials. For example, they must provide employees with the proper safety gear and training (see Figure 19.10). "
All hazardous waste is corrosive and explosive.,(A) true (B) false,B,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
At Love Canal,(A) the problem was uncovered by local residents (B) the local government detected the problem and dealt with it (C) the state government detected the problem and dealt with it (D) the federal government detected the problem and dealt with it,A,"The story of Love Canal, New York, begins in the 1950s, when a local chemical company placed hazardous wastes in 55-gallon steel drums and buried them. Love Canal was an abandoned waterway near Niagara Falls and was thought to be a safe site for hazardous waste disposal because the ground was fairly impermeable (Figure 1.1). After burial, the company covered the containers with soil and sold the land to the local school system for $1. The company warned the school district that the site had been used for toxic waste disposal. Steel drums were used to contain 21,000 tons of hazardous chemicals at Love Canal. Soon a school, a playground, and 100 homes were built on the site. The impermeable ground was breached when sewer systems were dug into the rock layer. Over time, the steel drums rusted and the chemicals were released into the ground. In the 1960s people began to notice bad odors. Children developed burns after playing in the soil, and they were often sick. In 1977 a swamp created by heavy rains was found to contain 82 toxic chemicals, including 11 suspected cancer-causing chemicals. A Love Canal resident, Lois Gibbs, organized a group of citizens called the Love Canal Homeowners Association to try to find out what was causing the problems (See opening image). When they discovered that toxic chemicals were buried beneath their homes and school, they demanded that the government take action to clean up the area and remove the chemicals. "
Electronic products contain toxic chemicals.,(A) true (B) false,A,"Some plastics contain toxic chemicals, such as bisphenol A. Plastics can also absorb organic pollutants that may be floating in the water, such as the pesticide DDT (which is banned in the U.S. but not in other nations) and some endocrine disruptors. "
Nations that produce the most hazardous waste have the most,(A) people (B) farmers (C) buildings (D) industry,D,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
Agriculture produces very little hazardous waste.,(A) true (B) false,B,The greatest source of hazardous waste is industry. Agriculture is another major source. Even households produce a lot of hazardous waste. 
No hazardous wastes can be recycled safely.,(A) true (B) false,B,"Thanks to the lessons of Love Canal, the U.S. now has laws requiring the safe disposal of hazardous waste. Companies must ensure that hazardous waste is not allowed to enter the environment in dangerous amounts. They must also protect their workers from hazardous materials. For example, they must provide employees with the proper safety gear and training (see Figure 19.10). "
Hazardous products should never be reused.,(A) true (B) false,B,"Cleaning products, lawn chemicals, paints, batteries, motor oil these are just some of the many hazardous materials that may be found in households. You might think that a household doesnt produce enough hazardous waste to worry about. But when you add up all the waste from all the households in a community, its a different story. A city of just 50,000 people might produce more than 40 tons of hazardous waste each year! Clearly, how households deal with hazardous waste matters. What can your family do? Reduce, reuse, recycle, or properly dispose of the wastes. 1. Reduce the amount of hazardous products you buy. For example, if you only need a quart of paint for a job, dont buy a gallon. 2. Use less hazardous products if you can. For example, clean windows with vinegar and water instead of toxic window cleaners. 3. Reuse products if its safe to do so. For example, paint thinner that has been used to clean paint brushes can be strained and reused. 4. Recycle whenever possible. For example, some service stations allow you to drop off used motor oil, car batteries, or tires for recycling. 5. Always properly dispose of hazardous waste. For example, let liquid waste evaporate before placing the container in the trash. Proper disposal depends on the waste. Many hazardous products have disposal guidelines on the label. Thats one reason why you should keep the products in their original containers. The labels also explain how to use the products safely. Follow the instructions to protect yourself and the environment. Most communities have centers for disposing of household hazardous waste (see Figure 19.11). Do you know how to dispose of hazardous waste in your community? "
You should never put old batteries in the trash.,(A) true (B) false,A,"If an item can no longer be used or reused, try to recycle it. Recycling means taking a used item, breaking it down, and reusing the components. It generally takes less energy to recycle materials than obtain new ones. Recycling also keeps waste out of landfills. Some of the items that can be recycled include: glass, paper, cardboard, plastic, aluminum, iron, steel, batteries, electronics, tires, and concrete. You can learn how some of these materials are recycled by watching this video:  . MEDIA Click image to the left or use the URL below. URL:  Even kitchen scraps and garden wastes can be recycled. They can be tossed into a compost bin, like the one in Figure 25.13. The recycled compost gradually breaks down to form rich humus that can be added to lawns and gardens to improve the soil. Encourage your family to recycle if they dont already. Even if you dont have curbside recycling where you live, there are likely to be recycling drop boxes or centers available for recycling many items. If you have recycling bins at school, be sure to use them. If not, raise the issue with your teacher or principal. You can also write a letter to the editor of your local newspaper encouraging everyone in your community to recycle. "
Most cities have centers for disposal of household hazardous waste.,(A) true (B) false,A,"Cleaning products, lawn chemicals, paints, batteries, motor oil these are just some of the many hazardous materials that may be found in households. You might think that a household doesnt produce enough hazardous waste to worry about. But when you add up all the waste from all the households in a community, its a different story. A city of just 50,000 people might produce more than 40 tons of hazardous waste each year! Clearly, how households deal with hazardous waste matters. What can your family do? Reduce, reuse, recycle, or properly dispose of the wastes. 1. Reduce the amount of hazardous products you buy. For example, if you only need a quart of paint for a job, dont buy a gallon. 2. Use less hazardous products if you can. For example, clean windows with vinegar and water instead of toxic window cleaners. 3. Reuse products if its safe to do so. For example, paint thinner that has been used to clean paint brushes can be strained and reused. 4. Recycle whenever possible. For example, some service stations allow you to drop off used motor oil, car batteries, or tires for recycling. 5. Always properly dispose of hazardous waste. For example, let liquid waste evaporate before placing the container in the trash. Proper disposal depends on the waste. Many hazardous products have disposal guidelines on the label. Thats one reason why you should keep the products in their original containers. The labels also explain how to use the products safely. Follow the instructions to protect yourself and the environment. Most communities have centers for disposing of household hazardous waste (see Figure 19.11). Do you know how to dispose of hazardous waste in your community? "
The Love Canal disaster began with the disposal of chemical wastes in a canal in the,(A) 1940s (B) 1950s (C) 1970s (D) 1980s,A,"The Love Canal disaster actually began back in the mid 1900s. The disaster continues even today. Starting in the early 1940s, a big chemical company put thousands of barrels of chemical waste into an old canal. Over the next 10 years, the company dumped almost 22,000 tons of chemicals into the ground! In the early 1950s, the company covered over the barrels in the canal with soil. Then they sold the land to the city for just a dollar. The city needed the land in order to build an elementary school. The company warned the city that toxic waste was buried there. But they thought the waste was safe. The school and hundreds of homes were also built over the old canal. As it turned out, the cheap price was no bargain. Chemicals started leaking from the barrels. Chemicals seeped into basements. Chemicals bubbled up to the surface of the ground. In some places, plants wouldnt even grow on the soil. People noticed bad smells. Many got sick, especially the children. Residents wanted to know if the old chemicals were the cause. But they had a hard time getting officials to listen. So they demonstrated and demanded answers. Finally, the soil was tested and was found to be contaminated with harmful chemicals. For example, it contained a lot of lead and mercury. Both can cause permanent damage to the human nervous system. The school was closed. More than 200 homes were evacuated. Much of the Love Canal neighborhood was bulldozed away. The area had a massive clean-up effort. The cleanup cost millions of dollars. More than three decades later, much of Love Canal is still too contaminated to be safe for people. "
"To dispose of liquid waste, let it evaporate.",(A) true (B) false,A,A liquid can also change to a gas without boiling. This process is called evaporation. It occurs when particles at the exposed surface of a liquid absorb just enough energy to pull away from the liquid and escape into the air. This happens faster at warmer temperatures. Look at the puddle in Figure 4.21. It formed in a pothole during a rain shower. The puddle will eventually evaporate. It will evaporate faster if the sun comes out and heats the water than if the sky remains cloudy. 
"After a massive cleanup effort costing millions of dollars, Love Canal was",(A) safe for people (B) no longer toxic (C) still contaminated (D) two of the above,C,"In 1978, people were relocated to safe areas. The problem of Love Canal was instrumental in the passage of the the Superfund Act in 1980. This law requires companies to be responsible for hazardous chemicals that they put into the environment and to pay to clean up polluted sites, which can often cost hundreds of millions of dollars. Love Canal became a Superfund site in 1983 and as a result, several measures were taken to secure the toxic wastes. The land was capped so that water could not reach the waste, debris was cleaned from the nearby area, and contaminated soils were removed. "
Batteries contain toxic materials and should be disposed of properly.,(A) true (B) false,A,"Cleaning products, lawn chemicals, paints, batteries, motor oil these are just some of the many hazardous materials that may be found in households. You might think that a household doesnt produce enough hazardous waste to worry about. But when you add up all the waste from all the households in a community, its a different story. A city of just 50,000 people might produce more than 40 tons of hazardous waste each year! Clearly, how households deal with hazardous waste matters. What can your family do? Reduce, reuse, recycle, or properly dispose of the wastes. 1. Reduce the amount of hazardous products you buy. For example, if you only need a quart of paint for a job, dont buy a gallon. 2. Use less hazardous products if you can. For example, clean windows with vinegar and water instead of toxic window cleaners. 3. Reuse products if its safe to do so. For example, paint thinner that has been used to clean paint brushes can be strained and reused. 4. Recycle whenever possible. For example, some service stations allow you to drop off used motor oil, car batteries, or tires for recycling. 5. Always properly dispose of hazardous waste. For example, let liquid waste evaporate before placing the container in the trash. Proper disposal depends on the waste. Many hazardous products have disposal guidelines on the label. Thats one reason why you should keep the products in their original containers. The labels also explain how to use the products safely. Follow the instructions to protect yourself and the environment. Most communities have centers for disposing of household hazardous waste (see Figure 19.11). Do you know how to dispose of hazardous waste in your community? "
Because of the lessons learned from Love Canal,(A) the Superfund Act was passed (B) many other contaminated sites were found (C) safer waste disposal guidelines were developed (D) all of the above,D,"In 1978, people were relocated to safe areas. The problem of Love Canal was instrumental in the passage of the the Superfund Act in 1980. This law requires companies to be responsible for hazardous chemicals that they put into the environment and to pay to clean up polluted sites, which can often cost hundreds of millions of dollars. Love Canal became a Superfund site in 1983 and as a result, several measures were taken to secure the toxic wastes. The land was capped so that water could not reach the waste, debris was cleaned from the nearby area, and contaminated soils were removed. "
The Superfund Act requires companies to be responsible for hazardous chemicals that they put into the,(A) true (B) false,A,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
Pesticides in any amount are not toxic to humans.,(A) true (B) false,B,"Chemical control of pests involves the use of insecticides. Insecticides, which are also known as pesticides, are most often used to kill insects. Insecticides are chemicals that kill insects. The U.S. spends $9 billion each year on pesticides. Disadvantages to using pesticides include human, fish, and honeybee poisonings, and the contamination of meat and dairy products. When choosing to use an insecticide, there are numerous points to consider. Negative effects of the pesticide should try to be minimized. Important questions to consider include the following. What is the chemicals success against the target pest? Will the insecticide provide the desired level of control of the pest? If the answer is no, other methods of control should be considered. Does the chemical have an impact on natural enemies of the pest? In large scale efforts to rid areas of mosquitoes, the insecticide used also killed the dragonfly. This effort removed a natural predator of the mosquito. This may be an unacceptable negative effect of using the insecticide. How susceptible is the crop to insect damage? If the crop is not heavily damaged, only minor pest control may be needed. This may affect the amount or type of insecticide used. How toxic is the chemical to the environment and humans? Some older insecticides are extremely poisonous. Keep in mind that users of these poisons have a community responsibility to minimize the contamination of the surrounding environment, as well as keeping animals, surrounding crops and humans safe. Does using the pesticide result in the development of resistance? If so, this can make additional use of the pesticide less effective. As the resistance will be passed to future generations of the insect (which is natural selection in action), this could be considered a negative side-effect of pesticide use. "
Hazardous waste may be dangerous because it is,(A) toxic (B) corrosive (C) flammable (D) all of the above,D,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
Toxic wastes can be located because they are always visible.,(A) true (B) false,B,"Sometimes the chemicals are not so easily seen as they were at Love Canal. But the impacts can be seen statistically. For example, contaminated drinking water may cause an increase in some types of cancer in a community. Why is one person with cancer not enough to suspect contamination by toxic waste? One is not a statistically valid number. A certain number of people get cancer all the time. To identify contamination, a number of cancers above the normal rate, called a cancer cluster, must be discovered. A case that was made into a book and movie called A Civil Action involved the community of Woburn, Massachusetts. Groundwater contamination was initially suspected because of an increase in childhood leukemia and other illnesses. As a result of concern by parents, the well water was analyzed and shown to have high levels of TCE (trichloroethylene). "
Examples of hazardous wastes include,(A) used brake fluid (B) old computers (C) left over paint (D) all of the above,D,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
"If you have a can containing a very small amount of paint thinner, how could you safely dispose of it?",(A) Dilute the paint thinner with water and then toss the can in the trash (B) Let the paint thinner evaporate and then put the can in the trash (C) Put the lid tightly on the can and then throw the can in the trash (D) Pour the paint thinner down the drain and then recycle the can,B,"Cleaning products, lawn chemicals, paints, batteries, motor oil these are just some of the many hazardous materials that may be found in households. You might think that a household doesnt produce enough hazardous waste to worry about. But when you add up all the waste from all the households in a community, its a different story. A city of just 50,000 people might produce more than 40 tons of hazardous waste each year! Clearly, how households deal with hazardous waste matters. What can your family do? Reduce, reuse, recycle, or properly dispose of the wastes. 1. Reduce the amount of hazardous products you buy. For example, if you only need a quart of paint for a job, dont buy a gallon. 2. Use less hazardous products if you can. For example, clean windows with vinegar and water instead of toxic window cleaners. 3. Reuse products if its safe to do so. For example, paint thinner that has been used to clean paint brushes can be strained and reused. 4. Recycle whenever possible. For example, some service stations allow you to drop off used motor oil, car batteries, or tires for recycling. 5. Always properly dispose of hazardous waste. For example, let liquid waste evaporate before placing the container in the trash. Proper disposal depends on the waste. Many hazardous products have disposal guidelines on the label. Thats one reason why you should keep the products in their original containers. The labels also explain how to use the products safely. Follow the instructions to protect yourself and the environment. Most communities have centers for disposing of household hazardous waste (see Figure 19.11). Do you know how to dispose of hazardous waste in your community? "
Assume you are going to use a bottle of a new cleaning product that you have never used before. What should you do first?,(A) Transfer the product to a disposable container (B) Read the safety guidelines on the label of the bottle (C) Test a small amount of the product to see if it is toxic (D) Put on latex gloves after you open the bottle,B,"Following basic safety rules is the best way to stay safe in science. Safe practices help prevent accidents. Several lab safety rules are listed below. Different rules may apply when you work in the field. But in all cases, you should always follow your teachers instructions. Lab Safety Rules Wear safety gear, including goggles, an apron, and gloves. Wear a long-sleeved shirt and shoes that completely cover your feet. Tie back your hair if it is long. Do not eat or drink in the lab. Never work alone. Never perform unauthorized experiments. Never point the open end of a test tube at yourself or another person. Always add acid to water never water to acid and add the acid slowly. To smell a substance, use your hand to fan vapors toward your nose rather than smell it directly. This is demonstrated in Figure 2.12. When disposing of liquids in the sink, flush them down the drain with lots of water. Wash glassware and counters when you finish your lab work. Thoroughly wash your hands with soap and water before leaving the lab. Even when you follow the rules, accidents can happen. Immediately alert your teacher if an accident occurs. Report all accidents, even if you dont think they are serious. "
highly reactive with other substances,(A) Superfund Act (B) hazardous waste (C) corrosive (D) flammable (E) pollution,C,"Reactivity is the ability of matter to combine chemically with other substances. Some kinds of matter are extremely reactive; others are extremely unreactive. For example, potassium is very reactive, even with water. When a pea- sized piece of potassium is added to a small amount of water, it reacts explosively. You can observe this reaction in the video below. (Caution: Dont try this at home!) In contrast, noble gases such as helium almost never react with any other substances. Click image to the left or use the URL below. URL: "
any waste that is dangerous to people or the environment,(A) Superfund Act (B) hazardous waste (C) corrosive (D) flammable (E) pollution,B,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
able to burn easily,(A) Superfund Act (B) hazardous waste (C) corrosive (D) flammable (E) pollution,D,"Have you ever seen a symbol that says ""Flammable""? You might see such a symbol on a gasoline can. Gasoline is highly flammable. That is why there are signs at the gas station that say, ""NO SMOKING."" Flammability is the ability of matter to burn. When matter burns, it combines with oxygen. When it does, it changes to different substances. Wood is an example of flammable matter, as seen in Figure 1.1. Q: How can you tell that wood ashes are a different substance than wood? A: Ashes have different properties than wood. For example, ashes are gray and powdery. Wood is brown and hard. Q: What are some other substances that have the property of flammability? A: Substances called fuels have the property of flammability. They include fossil fuels such as coal, natural gas, and petroleum. For example, gasoline is used in our cars because it is flammable. This property enables car engines to run. Substances made of wood, such as paper and cardboard, are also flammable. "
act of contaminating the environment,(A) Superfund Act (B) hazardous waste (C) corrosive (D) flammable (E) pollution,E,"Pollution adds chemicals, noise, heat, or even light to an environment. This can have many different harmful effects on all kinds of organisms. For example, the pesticide DDT nearly eliminated the peregrine falcon in some parts of the world. This pesticide caused falcons to lay eggs with thinner shells. As a result, fewer falcon eggs survived to hatching. Populations of peregrine falcons declined rapidly. DDT was then banned in the U.S. and peregrine falcon populations have recovered. Water pollution threatens vital freshwater and marine resources throughout the world ( Figure 1.1). Specifically, industrial and agricultural chemicals, waste, and acid rain threaten water. As water is essential for all ecosystems, water pollution can result in the extinction of species. A bird that was the victim of an oil spill. About 58,000 gallons of oil spilled from a South Korea-bound container ship when it struck a tower supporting the San Francisco-Oakland Bay Bridge in dense fog in November, 2007. Finally, soil contamination can also result in extinction. Soil contamination can come from toxic industrial and municipal wastes ( Figure 1.2), salts from irrigation, and pesticides from agriculture. These all degrade the soil as well. As soil is the foundation of terrestrial ecosystems, this can result in extinction. "
law requiring that money be set aside to clean up toxic waste sites,(A) Superfund Act (B) hazardous waste (C) corrosive (D) flammable (E) pollution,A,"Love Canal opened peoples eyes to toxic waste burial. They realized there must be other Love Canals all over the country. Thousands of contaminated sites were found. The Superfund Act was passed in 1980. The law required that money be set aside for cleanup of toxic waste sites, like the Elizabeth Copper Mine in Vermont (see the far-right image in Figure 19.9). The law also required safer disposal of hazardous waste in the future. "
Earths magnetic north pole is always located in the same place.,(A) true (B) false,B,"Imagine a huge bar magnet passing through Earths axis, as in the Figure 1.1. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles. A magnetic pole is the north or south end of a magnet, where the magnet exerts the most force. "
Continents,(A) are above sea level (B) are older than ocean basins (C) both a and b (D) none of the above,C,"Continents grow when microcontinents, or small continents, collide with each other or with a larger continent. Oceanic island arcs also collide with continents to make them grow. "
A compass needle points toward Earths true north.,(A) true (B) false,B,"Although the needle of a compass always points north, it doesnt point to Earths north geographic pole. Find the north geographic pole in the Figure 1.2. As you can see, it is located at 90 north latitude. Where does a compass Q: The north end of a compass needle points toward Earths north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesnt the north end of a compass needle point to Earths south magnetic pole instead? A: The answer may surprise you. The compass needle actually does point to the south pole of magnet Earth. However, it is called the north magnetic pole because it is close to the north geographic pole. This naming convention was adopted a long time ago to avoid confusion. "
Which of the following is NOT an example of a destructive force?,(A) A volcano blowing its top off (B) Rivers cutting away at rocks (C) Rivers bringing sand to the shore to form beaches (D) Wind wearing down mountains to become plateaus,C,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
All landforms are created by constructive forces.,(A) true (B) false,B,"If you take away the water in the oceans (Figure 2.6), Earth looks really different. You see that the surface has two main features: continents and ocean basins. Continents are large land areas. Ocean basins extend from the edges of continents to the ocean floor and into deep trenches. Continents are much older than ocean basins. Some rocks on the continents are billions of years old. Ocean basins are only millions of years old at their oldest. Because the continents are so old, a lot has happened to them! As we view the land around us we see landforms. Landforms are physical features on Earths surface. Landforms are introduced in this section but will be discussed more in later chapters. Constructive forces cause landforms to grow. Lava flowing into the ocean can build land outward. A volcano can be a constructive force. Destructive forces may blow landforms apart. A volcano blowing its top off is a destructive force. The destructive forces of weathering and erosion change landforms more slowly. Over millions of years, mountains are worn down by rivers and streams. Constructive and destructive forces work together to create landforms. Constructive forces create mountains and erosion may wear them away. Mountains are very large landforms. Mountains may wear away into a high flat area called a plateau, or a lower-lying plain. Interior plains are in the middle of continents. Coastal plains are on the edge of a continent, where it meets the ocean. Rivers and streams flow across continents. They cut away at rock, forming river valleys (Figure 2.8). These are "
A double compass rose,(A) shows both direction and location (B) is used by sailors (C) shows the difference between true north and magnetic north (D) both b and c are correct,C,"When an object is moving, it is not enough to describe its location. We also need to know direction. Direction is important for describing moving objects. For example, a wind blows a storm over your school. Where is that storm coming from? Where is it going? The most common way to describe direction is by using a compass. A compass is a device with a floating needle (Figure 2.1). The needle is a small magnet that aligns itself with the Earths magnetic field. The compass needle always points to magnetic north. If you have a compass and you find north, you can then know any other direction. See the directions, such as east, south, west, etc., on a compass rose. A compass needle lines up with Earths magnetic north pole. This is different from Earths geographic north pole, or true north. The geographic north pole is the top of the imaginary axis around which Earth rotates. The geographic north pole is much like the spindle of a spinning top. The location of the geographic north pole does not change. However, the magnetic north pole shifts in location over time. Depending on where you live, you can correct for the difference between the two poles when you use a map and a compass (Figure 2.2). Some maps have a double compass rose. This allows users to make the corrections between magnetic north and true north. An example is a nautical chart that boaters use to chart their positions at sea (Figure 2.3). "
"The terrain of an area, or the difference between high and low points in an area, is known as",(A) elevation (B) relief (C) height (D) landform differential,B,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
A mountain may wear away into a high flat area called a plateau.,(A) true (B) false,A,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
"Examples of landforms include hills, straits, and capes.",(A) true (B) false,A,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
Constructive forces,(A) create new land and features (B) build land outward (C) are responsible for creating mountains (D) all of the above,D,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
The ocean basin begins where the ocean meets the land.,(A) true (B) false,A,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
The continental shelf is the part of a continent that is under ocean water.,(A) true (B) false,A,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
The continental rise is formed by volcanic eruptions.,(A) true (B) false,B,Eruptions are found at divergent plate boundaries as continents break apart. The volcanoes in Figure 1.4 are in the East African Rift between the African and Arabian plates. Remember from the chapter Plate Tectonics that Baja California is being broken apart from mainland Mexico as another example of continental rifting. Click image to the left or use the URL below. URL:  The Cascade Range is formed by volca- noes created from subduction of oceanic crust beneath the North American conti- nent. 
Mid-ocean ridges form from sediments deposited by ocean water.,(A) true (B) false,B,"Plates move apart at mid-ocean ridges. Lava rises upward, erupts, and cools. Later, more lava erupts and pushes the original seafloor outward. This is seafloor spreading. Seafloor spreading forms new oceanic crust. The rising magma causes earthquakes. Most mid-ocean ridges are located deep below the sea. The island of Iceland sits right on the Mid-Atlantic ridge (Figure 6.17). "
The Mariana Trench is the deepest place on Earth.,(A) true (B) false,A,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
Latitude and longitude can describe direction.,(A) true (B) false,B,"Most maps use a grid of lines to help you to find your location. This grid system is called a geographic coordinate system. Using this system you can define your location by two numbers, latitude and longitude. Both numbers are angles between your location, the center of Earth, and a reference line (Figure 2.20). "
Elevation describes how far above sea level an object is.,(A) true (B) false,A,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
Continents can be billions of years old.,(A) true (B) false,A,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
Mid-ocean ridges are the deepest places in the ocean.,(A) true (B) false,B,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
The ocean basin begins where the ocean meets the land.,(A) true (B) false,A,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
difference in elevation of landforms in a region,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,E,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
land mass above sea level,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,C,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
relief over a given region,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,F,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
"figure on a map or nautical chart that shows north, south, east, and west",(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,B,"Direction is important if you want to go between two places. Directions are expressed as north (N), east (E), south (S), and west (W), with gradations in between. The most common way to describe direction in relation to the Earths surface is with a compass, a device with a floating needle that is actually a small magnet. The compass needle aligns itself with the Earths magnetic north pole. Since the magnetic north pole is 11.5 degrees offset from its geographic north pole on the axis of rotation, you must correct for this discrepancy. Map of the Visitor Center at Old Faithful, Yellowstone National Park, Wyoming. Without using a compass, we can say that to get to Old Faithful, you enter Yellowstone National Park at the South Entrance, drive north-northeast to West Thumb, and then drive west-northwest to Old Faithful. Click image to the left or use the URL below. URL: "
height of a land feature measured relative to sea level,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,D,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
device with a magnetic needle that is used to find the magnetic north pole,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,A,"Although the needle of a compass always points north, it doesnt point to Earths north geographic pole. Find the north geographic pole in the Figure 1.2. As you can see, it is located at 90 north latitude. Where does a compass Q: The north end of a compass needle points toward Earths north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesnt the north end of a compass needle point to Earths south magnetic pole instead? A: The answer may surprise you. The compass needle actually does point to the south pole of magnet Earth. However, it is called the north magnetic pole because it is close to the north geographic pole. This naming convention was adopted a long time ago to avoid confusion. "
physical feature on Earths surface,(A) compass (B) compass rose (C) continent (D) elevation (E) relief (F) topography (G) landform,G,"As you know, the surface of Earth is not flat. Some places are high and some places are low. For example, mountain ranges like the Sierra Nevada in California or the Andes in South America are high above the surrounding areas. We can describe the topography of a region by measuring the height or depth of that feature relative to sea level (Figure mountains, while others are more like small hills! Relief, or terrain, includes all the landforms of a region. A topographic map shows the height, or elevation, of features in an area. This includes mountains, craters, valleys, and rivers. For example, Figure 2.5 shows the San Francisco Peaks in northern Arizona. Features on the map include mountains, hills and lava flows. You can recognize these features from the differences in elevation. We will talk about some different landforms in the next section. "
You could use a topographic map to find the,(A) elevation of landforms in a region (B) average temperature of an area (C) population density of a region (D) type of vegetation in an area,A,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
Which statement about continents is true?,(A) They may have rocks that are billions of years old (B) They are younger than the ocean basins (C) They float on ocean water (D) none of the above,A,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
Constructive forces form,(A) mountains (B) river deltas (C) barrier islands (D) all of the above,D,"If you take away the water in the oceans (Figure 2.6), Earth looks really different. You see that the surface has two main features: continents and ocean basins. Continents are large land areas. Ocean basins extend from the edges of continents to the ocean floor and into deep trenches. Continents are much older than ocean basins. Some rocks on the continents are billions of years old. Ocean basins are only millions of years old at their oldest. Because the continents are so old, a lot has happened to them! As we view the land around us we see landforms. Landforms are physical features on Earths surface. Landforms are introduced in this section but will be discussed more in later chapters. Constructive forces cause landforms to grow. Lava flowing into the ocean can build land outward. A volcano can be a constructive force. Destructive forces may blow landforms apart. A volcano blowing its top off is a destructive force. The destructive forces of weathering and erosion change landforms more slowly. Over millions of years, mountains are worn down by rivers and streams. Constructive and destructive forces work together to create landforms. Constructive forces create mountains and erosion may wear them away. Mountains are very large landforms. Mountains may wear away into a high flat area called a plateau, or a lower-lying plain. Interior plains are in the middle of continents. Coastal plains are on the edge of a continent, where it meets the ocean. Rivers and streams flow across continents. They cut away at rock, forming river valleys (Figure 2.8). These are "
Which of the following can be both a constructive force and a destructive force?,(A) volcanic eruption (B) weathering (C) erosion (D) two of the above,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
The continental margin includes the continental,(A) shelf (B) slope (C) rise (D) all of the above,D,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
The abyssal plain makes up much of the,(A) interior of continents (B) deep-ocean trenches (C) floor of the ocean (D) mid-ocean ridges,C,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
The deepest places in the ocean are,(A) continental slopes (B) mid-ocean ridges (C) seamounts (D) trenches,D,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
distance north or south of the equator,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,D,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
Lines of latitude give the distance north and south of the,(A) Prime Meridian (B) Equator (C) North Pole (D) South Pole,B,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
map made by projecting one point on Earth onto a flat surface,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,C,"Earth is a round, three-dimensional ball. In a small area, Earth looks flat, so it is not hard to make accurate maps of a small place. When map makers want to map the round Earth on flat paper, they use projections. What happens if you try to flatten out the skin of a peeled orange? Or if you try to gift wrap a soccer ball? To flatten out, the orange peel must rip and its shape must become distorted. To wrap around object with flat paper requires lots of extra cuts and folds. A projection is a way to represent Earths curved surface on flat paper (Figure 2.14). There are many types of projections. Each uses a different way to change three dimensions into two dimensions. There are two basic methods that the map maker uses in projections: The map maker slices the sphere in some way and unfolds it to make a flat map, like flattening out an orange peel. The map maker can look at the sphere from a certain point and then translate this view onto a flat paper. Lets look at a few commonly used projections. "
A Mercator projection,(A) is a perfect likeness of Earth (B) uses a cone to create the map (C) distorts the size of continents near the poles the most (D) distorts Mexico more than Greenland,C,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
map made by projecting Earths surface onto a cylinder,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,G,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
Which is NOT true on a map legend?,(A) Blue is used to show water features (B) Purple lines show major roads (C) Black dots represent cities (D) The size of a city dots helps to show its population,B,"Look for the legend on the top left side of the map. It explains how this map records different features. You can see the following: The boundaries of the state show its shape. Black dots represent the cities. Each city is named. The size of the dot represents the population of the city. Red and brown lines show major roads that connect the cities. Blue lines show rivers. Their names are written in blue. Blue areas show lakes and other waterways the Gulf of Mexico, Biscayne Bay, and Lake Okeechobee. Names for bodies of water are also written in blue. A line or scale of miles shows the distance represented on the map an inch or centimeter on the map represents a certain amount of distance (miles or kilometers). The legend explains other features and symbols on the map. It is the convention for north to be at the top of a map. For this reason, a compass rose is not needed on most maps. You can use this map to find your way around Florida and get from one place to another along roadways. "
Which is NOT true of a Robinson projection?,(A) It is a completely accurate map with no distortions (B) It is more oval than rectangular (C) It is more accurate in size than the Mercator (D) It was created using mathematical formulas,A,"In 1963, Arthur Robinson made a map with more accurate sizes and shapes of land areas. He did this using mathematical formulas. The formulas could directly translate coordinates onto the map. This type of projection is shaped like an oval rather than a rectangle (Figure 2.19). Robinsons map is more accurate than a Mercator projection. The shapes and sizes of continents are closer to true. Robinsons map is best within 45 degrees of the equator. Distances along the equator and the lines parallel to it are true. However, the scales along each line of latitude are different. In 1988, the National Geographic Society began to use Robinsons projection for its world maps. Whatever map projection is used, maps help us find places and to be able to get from one place to another. So how do you find your location on a map? "
map made by projecting Earths surface onto a cone,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,A,"Instead of a cylinder, you could wrap the flat paper into a cone. Conic map projections use a cone shape to better represent regions near the poles (Figure 2.17). Conic projections are best where the cone shape touches the globe. This is along a line of latitude, usually the equator. "
distance east or west of the prime meridian,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,E,"Lines of longitude are circles that go around Earth from pole to pole, like the sections of an orange. Lines of longitude start at the Prime Meridian. The Prime Meridian is a circle that runs north to south and passes through Greenwich, England. Longitude tells you how far you are east or west from the Prime Meridian (Figure 2.21). You can remember latitude and longitude by doing jumping jacks. When your hands are above your head and your feet are together, say longitude (your body is long!). When you put your arms out to the side horizontally, say latitude (your head and arms make a cross, like the t in latitude). While you are jumping, your arms are going the same way as each of these grid lines: horizontal for latitude and vertical for longitude. "
Which is NOT true of the Prime Meridian?,(A) It is a line of longitude (B) It runs through Greenwich (C) England (D) c It is known as 0 degrees (E) d It runs from east to west,D,"The latitude mentioned above does not locate Old Faithful exactly, since a circle could be drawn that latitude north of the Equator. To locate Old Faithful we need another point - longitude. At Old Faithful the longitude is W110o 4957. Longitude lines are circles that go around the Earth from north to south, like the sections of an orange. Longitude is measured perpendicular to the Equator. The Prime Meridian is 0o longitude and passes through Greenwich, England. The International Date Line is the 180o meridian. Old Faithful is in the Western Hemisphere, between the Prime Meridian in the east and the International Date Line in the west. "
numbers in a grid that locate a particular point,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,B,"Most maps use a grid of lines to help you to find your location. This grid system is called a geographic coordinate system. Using this system you can define your location by two numbers, latitude and longitude. Both numbers are angles between your location, the center of Earth, and a reference line (Figure 2.20). "
any method of representing Earths curved surface in two dimensions,(A) conic map (B) coordinates (C) gnomonic map (D) latitude (E) longitude (F) projection (G) Mercator projection,F,"Earth is a round, three-dimensional ball. In a small area, Earth looks flat, so it is not hard to make accurate maps of a small place. When map makers want to map the round Earth on flat paper, they use projections. What happens if you try to flatten out the skin of a peeled orange? Or if you try to gift wrap a soccer ball? To flatten out, the orange peel must rip and its shape must become distorted. To wrap around object with flat paper requires lots of extra cuts and folds. A projection is a way to represent Earths curved surface on flat paper (Figure 2.14). There are many types of projections. Each uses a different way to change three dimensions into two dimensions. There are two basic methods that the map maker uses in projections: The map maker slices the sphere in some way and unfolds it to make a flat map, like flattening out an orange peel. The map maker can look at the sphere from a certain point and then translate this view onto a flat paper. Lets look at a few commonly used projections. "
All map projections have some disadvantage.,(A) true (B) false,A,"Earth is a round, three-dimensional ball. In a small area, Earth looks flat, so it is not hard to make accurate maps of a small place. When map makers want to map the round Earth on flat paper, they use projections. What happens if you try to flatten out the skin of a peeled orange? Or if you try to gift wrap a soccer ball? To flatten out, the orange peel must rip and its shape must become distorted. To wrap around object with flat paper requires lots of extra cuts and folds. A projection is a way to represent Earths curved surface on flat paper (Figure 2.14). There are many types of projections. Each uses a different way to change three dimensions into two dimensions. There are two basic methods that the map maker uses in projections: The map maker slices the sphere in some way and unfolds it to make a flat map, like flattening out an orange peel. The map maker can look at the sphere from a certain point and then translate this view onto a flat paper. Lets look at a few commonly used projections. "
Both Robinson and Mercator Projections have distortion at the poles more than at the equator.,(A) true (B) false,A,"In 1963, Arthur Robinson made a map with more accurate sizes and shapes of land areas. He did this using mathematical formulas. The formulas could directly translate coordinates onto the map. This type of projection is shaped like an oval rather than a rectangle (Figure 2.19). Robinsons map is more accurate than a Mercator projection. The shapes and sizes of continents are closer to true. Robinsons map is best within 45 degrees of the equator. Distances along the equator and the lines parallel to it are true. However, the scales along each line of latitude are different. In 1988, the National Geographic Society began to use Robinsons projection for its world maps. Whatever map projection is used, maps help us find places and to be able to get from one place to another. So how do you find your location on a map? "
Gnomonic projections are most accurate when used for small geographic areas.,(A) true (B) false,A,What if want to wrap a different approach? Lets say you dont want to wrap a flat piece of paper around a round object? You could put a flat piece of paper right on the area that you want to map. This type of map is called a gnomonic map projection (Figure 2.18). The paper only touches Earth at one point. The sizes and shapes of countries near that point are good. The poles are often mapped this way to avoid distortion. A gnomic projection is best for use over a small area. 
"The Mercator Projection, unlike most other maps, represents the world with South at the top of the map.",(A) true (B) false,B,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
A globe is the most detailed map we have of Earth.,(A) true (B) false,B,"Earth is a sphere and so is a globe. A globe is the best way to make a map of the whole Earth. Because both the planet and a globe have curved surfaces, the sizes and shapes of countries are not distorted. Distances are true to scale. (Figure 2.23). Globes usually have a geographic coordinate system and a scale. The shortest distance between two points on a globe is the length of the portion of a circle that connects them. Globes are difficult to make and carry around. They also cannot be enlarged to show the details of any particular area. Globes are best sitting on your desk for reference. Google Earth is a neat site to download to your computer. This is a link that you can follow to get there: http://w tilt your image and lots more. "
The top of a map generally represents north.,(A) true (B) false,A,"Look for the legend on the top left side of the map. It explains how this map records different features. You can see the following: The boundaries of the state show its shape. Black dots represent the cities. Each city is named. The size of the dot represents the population of the city. Red and brown lines show major roads that connect the cities. Blue lines show rivers. Their names are written in blue. Blue areas show lakes and other waterways the Gulf of Mexico, Biscayne Bay, and Lake Okeechobee. Names for bodies of water are also written in blue. A line or scale of miles shows the distance represented on the map an inch or centimeter on the map represents a certain amount of distance (miles or kilometers). The legend explains other features and symbols on the map. It is the convention for north to be at the top of a map. For this reason, a compass rose is not needed on most maps. You can use this map to find your way around Florida and get from one place to another along roadways. "
A geographic map shows types and locations of rocks in an area.,(A) true (B) false,B,"A geologic map shows the different rocks that are exposed at the surface of a region. Rock units are shown in a color identified in a key. On the geologic map of the Grand Canyon, for example, different rock types are shown in different colors. Some people call the Grand Canyon layer cake geology because most of the rock units are in layers. Rock units show up on both sides of a stream valley. A geologic map looks very complicated in a region where rock layers have been folded, like the patterns in marble cake. Faults are seen on this geologic map cutting across rock layers. When rock layers are tilted, you will see stripes of each layer on the map. There are symbols on a geologic map that tell you which direction the rock layers slant, and often there is a cut away diagram, called a cross section, that shows what the rock layers look like below the surface. A large-scale geologic map will just show geologic provinces. They do not show the detail of individual rock layers. "
Mercator projections are no longer used today.,(A) true (B) false,B,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
"On a Mercator projection, landmasses near the poles are reduced in size.",(A) true (B) false,B,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
The poles are often mapped with gnomonic projections to avoid distortion.,(A) true (B) false,A,What if want to wrap a different approach? Lets say you dont want to wrap a flat piece of paper around a round object? You could put a flat piece of paper right on the area that you want to map. This type of map is called a gnomonic map projection (Figure 2.18). The paper only touches Earth at one point. The sizes and shapes of countries near that point are good. The poles are often mapped this way to avoid distortion. A gnomic projection is best for use over a small area. 
A Robinson projection is more accurate than a Mercator projection.,(A) true (B) false,A,"In 1963, Arthur Robinson made a map with more accurate sizes and shapes of land areas. He did this using mathematical formulas. The formulas could directly translate coordinates onto the map. This type of projection is shaped like an oval rather than a rectangle (Figure 2.19). Robinsons map is more accurate than a Mercator projection. The shapes and sizes of continents are closer to true. Robinsons map is best within 45 degrees of the equator. Distances along the equator and the lines parallel to it are true. However, the scales along each line of latitude are different. In 1988, the National Geographic Society began to use Robinsons projection for its world maps. Whatever map projection is used, maps help us find places and to be able to get from one place to another. So how do you find your location on a map? "
Lines of latitude meet at the poles.,(A) true (B) false,B,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
Lines of longitude are all parallel to one another.,(A) true (B) false,B,"Lines of longitude are circles that go around Earth from pole to pole, like the sections of an orange. Lines of longitude start at the Prime Meridian. The Prime Meridian is a circle that runs north to south and passes through Greenwich, England. Longitude tells you how far you are east or west from the Prime Meridian (Figure 2.21). You can remember latitude and longitude by doing jumping jacks. When your hands are above your head and your feet are together, say longitude (your body is long!). When you put your arms out to the side horizontally, say latitude (your head and arms make a cross, like the t in latitude). While you are jumping, your arms are going the same way as each of these grid lines: horizontal for latitude and vertical for longitude. "
You can find your location on a map if you know only your latitude and longitude.,(A) true (B) false,A,"If you know the latitude and longitude of a place, you can find it on a map. Simply place one finger on the latitude on the vertical axis of the map. Place your other finger on the longitude along the horizontal axis of the map. Move your fingers along the latitude and longitude lines until they meet. For example, say the location you want to find is at 30o N and 90o W. Place your right finger along 30o N at the right of the map. Place your left finger along the bottom at 90o W. Move your fingers along the lines until they meet. Your location should be near New Orleans, Louisiana, along the Gulf coast of the United States. What if you want to know the latitude and longitude of your location? If you know where you are on a map, point to the place with your fingers. Take one finger and move it along the latitude line to find your latitude. Then move another finger along the longitude line to find your and longitude. "
Distances are true to scale on a globe.,(A) true (B) false,A,"Earth is a sphere and so is a globe. A globe is the best way to make a map of the whole Earth. Because both the planet and a globe have curved surfaces, the sizes and shapes of countries are not distorted. Distances are true to scale. (Figure 2.23). Globes usually have a geographic coordinate system and a scale. The shortest distance between two points on a globe is the length of the portion of a circle that connects them. Globes are difficult to make and carry around. They also cannot be enlarged to show the details of any particular area. Globes are best sitting on your desk for reference. Google Earth is a neat site to download to your computer. This is a link that you can follow to get there: http://w tilt your image and lots more. "
Types of maps include,(A) relief maps (B) climate maps (C) geologic maps (D) all of the above,D,"There are many other types of maps besides road maps. Some examples include: Political or geographic maps show the outlines and borders of states and/or countries. Satellite view maps show terrains and vegetation forests, deserts, and mountains. Relief maps show elevations of areas, but usually on a larger scale, such as the whole Earth, rather than a local area. Topographic maps show detailed elevations of features on the map. Climate maps show average temperatures and rainfall. Precipitation maps show the amount of rainfall in different areas. Weather maps show storms, air masses, and fronts. Radar maps show storms and rainfall. Geologic maps detail the types and locations of rocks found in an area. These are but a few types of maps that various Earth scientists might use. You can easily carry a map around in your pocket or bag. Maps are easy to use because they are flat or two-dimensional. However, the world is three- dimensional. So, how do map makers represent a three-dimensional world on flat paper? "
The Mercator projection was invented in the,(A) 1300s (B) 1500s (C) 1700s (D) 1900s,B,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
A map in which all the lines of latitude and longitude are straight lines is a,(A) gnomonic projection (B) Robinson projection (C) Mercator projection (D) conic projection,C,"In 1569, Gerardus Mercator (1512-1594) (Figure 2.15) figured out a way to make a flat map of our round world, called the Mercator projection (Figure 2.16). Imagine wrapping the round, ball-shaped Earth with a big, flat piece of paper. First you make a tube or a cylinder. The cylinder will touch Earth at its fattest part, the equator. The equator is the imaginary line running horizontally around the middle of Earth. The poles are the farthest points from the cylinder. If you shine a light from the inside of your model Earth out to the cylinder, the image projected onto the paper is a Mercator projection. Where does the projection represent Earth best? Where is it worst? Your map would be most correct at the equator. The shapes and sizes of continents become more stretched out near the poles. Early sailors and navigators found the Mercator map useful because most explorations were located near the equator. Many world maps still use the Mercator projection. The Mercator projection is best within 15 degrees north or south of the equator. Landmasses or countries outside that zone get stretched out of shape. The further the feature is from the equator, the more out of shape it is stretched. For example, if you look at Greenland on a globe, you see it is a relatively small country near the North Pole. Yet, on a Mercator projection, Greenland looks almost as big the United States. Because Greenland is closer to the pole, the continents shape and size are greatly increased. The United States is closer to its true dimensions. In a Mercator projection, all compass directions are straight lines. This makes it a good type of map for navigation. The top of the map is north, the bottom is south, the left side is west and the right side is east. However, because it is a flat map of a curved surface, a straight line on the map is not the shortest distance between the two points it connects. "
Which type of map would you use if you wanted a very accurate representation of a tiny part of Earths surface?,(A) conic projection (B) gnomonic projection (C) Mercator projection (D) Robinson projection,B,"Imagine you are going on a road trip. Perhaps you are going on vacation. How do you know where to go? Most likely, you will use a map. A map is a picture of specific parts of Earths surface. There are many types of maps. Each map gives us different information. Lets look at a road map, which is the probably the most common map that you use (Figure 2.13). "
You know whether a place is in the northern or southern hemisphere based on its,(A) latitude (B) longitude (C) projection (D) prime meridian,A,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
Which coordinates represent a location within the continental United States?,(A) 35 N (B) 95 W (C) b 35 S (D) 95 W (E) c 35 N (F) 95 E (G) d 35 S (H) 95 E,A,"Most maps use a grid of lines to help you to find your location. This grid system is called a geographic coordinate system. Using this system you can define your location by two numbers, latitude and longitude. Both numbers are angles between your location, the center of Earth, and a reference line (Figure 2.20). "
"To move to a location that is 4 meters west of your current position, you would need a",(A) compass (B) metric ruler or tape (C) Mercator projection (D) two of the above,D,"Things dont always move in straight lines like the route from Mias house to the school. Sometimes they change direction as they move. For example, the route from Mias house to the post office changes from west to north at the school (see Figure 12.4). To find the total distance of a route that changes direction, you must add up the distances traveled in each direction. From Mias house to the school, for example, the distance is 2 kilometers. From the school to the post office, the distance is 1 kilometer. Therefore, the total distance from Mias house to the post office is 3 kilometers. You Try It! Problem: What is the distance from the post office to the park in Figure 12.4? Direction is just as important as distance in describing motion. For example, if Mia told a friend how to reach the post office from her house, she couldnt just say, ""go 3 kilometers."" The friend might end up at the park instead of the post office. Mia would have to be more specific. She could say, ""go west for 2 kilometers and then go north for 1 kilometer."" When both distance and direction are considered, motion is a vector. A vector is a quantity that includes both size and direction. A vector is represented by an arrow. The length of the arrow represents distance. The way the arrow points shows direction. The red arrows in Figure 12.4 are vectors for Mias route to the school and post office. If you want to learn more about vectors, watch the videos at these URLs:  (5:27) MEDIA Click image to the left or use the URL below. URL:  You Try It! Problem: Draw vectors to represent the route from the post office to the park in Figure 12.4. "
"On a topographic map, only the contour lines that are numbered represent changes in elevation.",(A) true (B) false,B,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
A cross section,(A) can show the inside of something (B) is a type of topographic map (C) cannot used with bathymetric maps (D) uses concentric circles to show elevations,A,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
Two contour lines on a topographic may be parallel or they may intersect each other.,(A) true (B) false,B,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
Which is NOT true of a bathymetric map?,(A) it is a type of topographic map (B) larger numbers show great depths (C) negative numbers are used to show depths below sea level (D) it is often made using sonar,C,"A bathymetric map is like a topographic map with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth. Kilauea is the youngest volcano found above sea level in Hawaii. On the flank of Kilauea is an even younger volcano called Loihi. The bathymetric map pictured in the Figure 1.2 shows the form of Loihi. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. A geologic map of the region around Old Faithful, Yellowstone National Park. "
The contour interval of a topographic map represents the horizontal distance between contour lines.,(A) true (B) false,B,"Since each contour line represents a specific elevation, two different contour are separated by the same difference in elevation (e.g. 20 ft or 100 ft.). This difference between contour lines is called the contour interval. You can calculate the contour interval by following these steps: a. Take the difference in elevation between 2 bold lines. b. Divide that difference by the number of contour lines between them. Imagine that the difference between two bold lines is 100 feet and there are five lines between them. What is the contour interval? If you answered 20 feet, then you are correct (100 ft/5 lines = 20 ft between lines). The legend on the map also gives the contour interval. "
Contour lines that create a V shape indicate what?,(A) a stream channel (B) a hilltop (C) a valley (D) a cliff,A,Contour lines connect all the points on the map that have the same elevation. Lets take a closer look at this (Figure Each contour line represents a specific elevation. The contour line connects all the points that are at the same elevation. Every fifth contour line is made bold. The bold contour lines have numbers to show elevation. Contour lines run next to each other and NEVER cross one another. If the lines crossed it would mean that one place had two different elevations. This cannot happen. 
Which of the following is a topographic map NOT able to do?,(A) show the slope of an area (B) show the horizontal scale (C) give details about the land use in an area (D) determine the direction of water flow,C,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
You can use a topographic map to determine the slope of the land.,(A) true (B) false,A,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
"On a bathymetric map, contour lines represent the distance to the bottom of the water.",(A) true (B) false,A,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
"If elevation between 2 bold lines is 1000 feet, and there are 5 lines in between the bold lines, what is the contour interval?",(A) 5 (B) 200 (C) 500 (D) 2000,B,"Since each contour line represents a specific elevation, two different contour are separated by the same difference in elevation (e.g. 20 ft or 100 ft.). This difference between contour lines is called the contour interval. You can calculate the contour interval by following these steps: a. Take the difference in elevation between 2 bold lines. b. Divide that difference by the number of contour lines between them. Imagine that the difference between two bold lines is 100 feet and there are five lines between them. What is the contour interval? If you answered 20 feet, then you are correct (100 ft/5 lines = 20 ft between lines). The legend on the map also gives the contour interval. "
A topographic map can be used to determine the direction that rivers and streams flow.,(A) true (B) false,A,"Earth scientists use topographic maps for many things: Describing and locating surface features, especially geologic features. Determining the slope of the Earths surface. Determining the direction of flow for surface water, groundwater, and mudslides. Hikers, campers, and even soldiers use topographic maps to locate their positions in the field. Civil engineers use topographic maps to determine where roads, tunnels, and bridges should go. Land use planners and architects use topographic maps when planning development projects, such as housing projects, shopping malls, and roads. "
A topographic map of a mountain shows which side of the mountain is steepest.,(A) true (B) false,A,"How does a topographic map tell you about the terrain? Lets consider the following principles: 1. The spacing of contour lines shows the slope of the land. Contour lines that are close together indicate a steep slope. This is because the elevation changes quickly in a small area. Contour lines that seem to touch indicate a very steep slope, like a cliff. When contour lines are spaced far apart the slope is gentle. So contour lines help us see the three-dimensional shape of the land. Look at the topographic map of Stowe, Vermont (Figure 2.28). There is a steep hill rising just to the right of the city of Stowe. You can tell this because the contour lines there are closely spaced. The contour lines also show that the hill has a sharp rise of about 200 feet. Then the slope becomes less steep toward the right. 2. Concentric circles indicate a hill. Figure 2.29 shows another side of the topographic map of Stowe, Vermont. When contour lines form closed loops, there is a hill. The smallest loops are the higher elevations on the hill. The larger loops encircling the smaller loops are downhill. If you look at the map, you can see Cady Hill in the lower left and another, smaller hill in the upper right. 3. Hatched concentric circles indicate a depression. The hatch marks are short, perpendicular lines inside the circle. The innermost hatched circle represents the deepest part of the depression. The outer hatched circles represent higher elevations (Figure 2.30). 4. V-shaped portions of contour lines indicate stream valleys. The V shape of the contour lines point uphill. There is a V shape because the stream channel passes through the point of the V. The open end of the V represents the downstream portion. A blue line indicates that there is water running through the valley. If there is not a blue line the V pattern indicates which way water flows. In Figure 2.31, you can see examples of V-shaped markings. Try to find the direction a stream flows. 5. Like other maps, topographic maps have a scale so that you can find the horizontal distance. You can use the horizontal scale to calculate the slope of the land (vertical height/horizontal distance). Common scales used in United States Geological Service (USGS) maps include the following: 1:24,000 scale - 1 inch = 2000 ft 1:100,000 scale - 1 inch = 1.6 miles 1:250,000 scale - 1 inch = 4 miles Including contour lines, contour intervals, circles, and V-shapes allows a topographic map to show three-dimensional information on a flat piece of paper. A topographic map gives us a good idea of the shape of the land. "
"If contour lines are so close together that they almost touch, they represent a plain or plateau.",(A) true (B) false,B,Contour lines connect all the points on the map that have the same elevation. Lets take a closer look at this (Figure Each contour line represents a specific elevation. The contour line connects all the points that are at the same elevation. Every fifth contour line is made bold. The bold contour lines have numbers to show elevation. Contour lines run next to each other and NEVER cross one another. If the lines crossed it would mean that one place had two different elevations. This cannot happen. 
Topographic maps are useful only to geologists and other Earth scientists.,(A) true (B) false,B,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
Geologic maps use different colors to represent different types of rocks.,(A) true (B) false,A,"A geologic map shows the different rocks that are exposed at the surface of a region. Rock units are shown in a color identified in a key. On the geologic map of the Grand Canyon, for example, different rock types are shown in different colors. Some people call the Grand Canyon layer cake geology because most of the rock units are in layers. Rock units show up on both sides of a stream valley. A geologic map looks very complicated in a region where rock layers have been folded, like the patterns in marble cake. Faults are seen on this geologic map cutting across rock layers. When rock layers are tilted, you will see stripes of each layer on the map. There are symbols on a geologic map that tell you which direction the rock layers slant, and often there is a cut away diagram, called a cross section, that shows what the rock layers look like below the surface. A large-scale geologic map will just show geologic provinces. They do not show the detail of individual rock layers. "
The difference between two contour lines is the contour interval.,(A) true (B) false,A,"Since each contour line represents a specific elevation, two different contour are separated by the same difference in elevation (e.g. 20 ft or 100 ft.). This difference between contour lines is called the contour interval. You can calculate the contour interval by following these steps: a. Take the difference in elevation between 2 bold lines. b. Divide that difference by the number of contour lines between them. Imagine that the difference between two bold lines is 100 feet and there are five lines between them. What is the contour interval? If you answered 20 feet, then you are correct (100 ft/5 lines = 20 ft between lines). The legend on the map also gives the contour interval. "
Contour lines help us to see the three-dimensional shape of the land.,(A) true (B) false,A,"How does a topographic map tell you about the terrain? Lets consider the following principles: 1. The spacing of contour lines shows the slope of the land. Contour lines that are close together indicate a steep slope. This is because the elevation changes quickly in a small area. Contour lines that seem to touch indicate a very steep slope, like a cliff. When contour lines are spaced far apart the slope is gentle. So contour lines help us see the three-dimensional shape of the land. Look at the topographic map of Stowe, Vermont (Figure 2.28). There is a steep hill rising just to the right of the city of Stowe. You can tell this because the contour lines there are closely spaced. The contour lines also show that the hill has a sharp rise of about 200 feet. Then the slope becomes less steep toward the right. 2. Concentric circles indicate a hill. Figure 2.29 shows another side of the topographic map of Stowe, Vermont. When contour lines form closed loops, there is a hill. The smallest loops are the higher elevations on the hill. The larger loops encircling the smaller loops are downhill. If you look at the map, you can see Cady Hill in the lower left and another, smaller hill in the upper right. 3. Hatched concentric circles indicate a depression. The hatch marks are short, perpendicular lines inside the circle. The innermost hatched circle represents the deepest part of the depression. The outer hatched circles represent higher elevations (Figure 2.30). 4. V-shaped portions of contour lines indicate stream valleys. The V shape of the contour lines point uphill. There is a V shape because the stream channel passes through the point of the V. The open end of the V represents the downstream portion. A blue line indicates that there is water running through the valley. If there is not a blue line the V pattern indicates which way water flows. In Figure 2.31, you can see examples of V-shaped markings. Try to find the direction a stream flows. 5. Like other maps, topographic maps have a scale so that you can find the horizontal distance. You can use the horizontal scale to calculate the slope of the land (vertical height/horizontal distance). Common scales used in United States Geological Service (USGS) maps include the following: 1:24,000 scale - 1 inch = 2000 ft 1:100,000 scale - 1 inch = 1.6 miles 1:250,000 scale - 1 inch = 4 miles Including contour lines, contour intervals, circles, and V-shapes allows a topographic map to show three-dimensional information on a flat piece of paper. A topographic map gives us a good idea of the shape of the land. "
"Concentric lines that are very far apart show a high, steep hill.",(A) true (B) false,B,"How does a topographic map tell you about the terrain? Lets consider the following principles: 1. The spacing of contour lines shows the slope of the land. Contour lines that are close together indicate a steep slope. This is because the elevation changes quickly in a small area. Contour lines that seem to touch indicate a very steep slope, like a cliff. When contour lines are spaced far apart the slope is gentle. So contour lines help us see the three-dimensional shape of the land. Look at the topographic map of Stowe, Vermont (Figure 2.28). There is a steep hill rising just to the right of the city of Stowe. You can tell this because the contour lines there are closely spaced. The contour lines also show that the hill has a sharp rise of about 200 feet. Then the slope becomes less steep toward the right. 2. Concentric circles indicate a hill. Figure 2.29 shows another side of the topographic map of Stowe, Vermont. When contour lines form closed loops, there is a hill. The smallest loops are the higher elevations on the hill. The larger loops encircling the smaller loops are downhill. If you look at the map, you can see Cady Hill in the lower left and another, smaller hill in the upper right. 3. Hatched concentric circles indicate a depression. The hatch marks are short, perpendicular lines inside the circle. The innermost hatched circle represents the deepest part of the depression. The outer hatched circles represent higher elevations (Figure 2.30). 4. V-shaped portions of contour lines indicate stream valleys. The V shape of the contour lines point uphill. There is a V shape because the stream channel passes through the point of the V. The open end of the V represents the downstream portion. A blue line indicates that there is water running through the valley. If there is not a blue line the V pattern indicates which way water flows. In Figure 2.31, you can see examples of V-shaped markings. Try to find the direction a stream flows. 5. Like other maps, topographic maps have a scale so that you can find the horizontal distance. You can use the horizontal scale to calculate the slope of the land (vertical height/horizontal distance). Common scales used in United States Geological Service (USGS) maps include the following: 1:24,000 scale - 1 inch = 2000 ft 1:100,000 scale - 1 inch = 1.6 miles 1:250,000 scale - 1 inch = 4 miles Including contour lines, contour intervals, circles, and V-shapes allows a topographic map to show three-dimensional information on a flat piece of paper. A topographic map gives us a good idea of the shape of the land. "
The hatch marks on a topographic map are drawn on the side of the circle with the higher elevation.,(A) true (B) false,B,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
"While topographic maps can show vertical distances, they cannot show horizontal distances.",(A) true (B) false,B,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
feature on a topographic map represented by concentric contour lines with hatch marks,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,D,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
map that shows water depths in a body of water,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,F,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
difference in elevation between adjacent contour lines on a topographic map,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,A,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
map that shows elevations of features on Earths surface,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,B,"There are many other types of maps besides road maps. Some examples include: Political or geographic maps show the outlines and borders of states and/or countries. Satellite view maps show terrains and vegetation forests, deserts, and mountains. Relief maps show elevations of areas, but usually on a larger scale, such as the whole Earth, rather than a local area. Topographic maps show detailed elevations of features on the map. Climate maps show average temperatures and rainfall. Precipitation maps show the amount of rainfall in different areas. Weather maps show storms, air masses, and fronts. Radar maps show storms and rainfall. Geologic maps detail the types and locations of rocks found in an area. These are but a few types of maps that various Earth scientists might use. You can easily carry a map around in your pocket or bag. Maps are easy to use because they are flat or two-dimensional. However, the world is three- dimensional. So, how do map makers represent a three-dimensional world on flat paper? "
feature on a topographic map represented by concentric contour lines without hatch marks,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,G,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
line connecting points with the same elevation on a topographic map,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,C,Contour lines connect all the points on the map that have the same elevation. Lets take a closer look at this (Figure Each contour line represents a specific elevation. The contour line connects all the points that are at the same elevation. Every fifth contour line is made bold. The bold contour lines have numbers to show elevation. Contour lines run next to each other and NEVER cross one another. If the lines crossed it would mean that one place had two different elevations. This cannot happen. 
feature on a topographic map represented by v-shaped contour lines,(A) contour interval (B) topographic map (C) contour line (D) depression (E) river valley (F) bathymetric map (G) hill,E,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
What is the contour interval on this metric topographic map?,(A) 100 meters (B) 50 meters (C) 20 meters (D) 10 meters,C,"Since each contour line represents a specific elevation, two different contour are separated by the same difference in elevation (e.g. 20 ft or 100 ft.). This difference between contour lines is called the contour interval. You can calculate the contour interval by following these steps: a. Take the difference in elevation between 2 bold lines. b. Divide that difference by the number of contour lines between them. Imagine that the difference between two bold lines is 100 feet and there are five lines between them. What is the contour interval? If you answered 20 feet, then you are correct (100 ft/5 lines = 20 ft between lines). The legend on the map also gives the contour interval. "
Which best describes a geostationary orbit?,(A) A satellite orbit that can see the entire Earth in about 24 hours (B) A satellite orbit that is used to accurately pinpoint a location using radio signals (C) A satellite that stays above one location (D) A satellite orbit that is very high above the Earth and collect data on a single geographic point on the,C,"A satellite in a geostationary orbit flies above the planet at a distance of 36,000 km. It takes 24 hours to complete one orbit. The satellite and the Earth both complete one rotation in 24 hours. This means that the satellite stays over the same spot. Weather satellites use this type of orbit to observe changing weather conditions over a region. Communications satellites, like satellite TV, use this type of orbit to keep communications going full time. "
Scientific satellites can be used,(A) by NOAA (B) NASA and USGS (C) b to detect things such as the ocean levels (D) c to carry instruments that allow for measurements such as temperatures or atmospheric gas levels (E) d all of the above,D,"The National Aeronautics and Space Administration (NASA) has launched a fleet of satellites to study the Earth (Figure 2.36). The satellites are operated by several government agencies, including NASA, the National Oceano- graphic and Atmospheric Administration (NOAA), and the United States Geological Survey (USGS). By using different types of scientific instruments, satellites make many kinds of measurements of the Earth. Some satellites measure the temperatures of the land and oceans. Some record amounts of gases in the atmosphere, such as water vapor and carbon dioxide. Some measure their height above the oceans very precisely. From this information, they can measure sea level. Some measure the ability of the surface to reflect various colors of light. This information tells us about plant life. Some examples of the images from these types of satellites are shown in Figure 2.37. "
Which of the following is not true of GPS?,(A) it stands for Global Positioning System (B) it was first used by the US (C) it makes use of travel times of infrared waves in order to know distances (D) it relies on both a GPS receiver at the point of interest and satellites,C,Satellites continually orbit Earth and can be used to indicate location. A global positioning system receiver detects radio signals from at least four nearby GPS satellites. The receiver measures the time it takes for radio signals to travel from a satellite and then calculates its distance from the satellite using the speed of radio signals. By calculating distances from each of the four satellites the receiver can triangulate to determine its location. You can use a GPS meter to tell you how to get to Old Faithful. 
In which way can a satellite be used to help with safety?,(A) satellites can better predict weather to warn people of severe storms or hurricanes (B) satellites keep people from getting lost when they use GPS (C) satellites can communicate important information to television stations to warn of a dangerous situation (D) all of the above,D,Satellites can be used to monitor more than just gases (Figure 8.13). Satellites can look for high temperature spots or areas where the volcano surface is changing. This allows scientists to detect changes accurately and safely. 
Computer maps,(A) are often able to display more information than traditional maps (B) cannot put multiple pieces of satellite data together (C) are not more accurate (D) but are often more visually pleasing (E) d all of the above,A,"Prior to the late 20th and early 21st centuries, mapmakers sent people out in the field to determine the boundaries and locations for various features for maps. State or county borders were used to mark geological features. Today, people in the field use GPS receivers to mark the locations of features. Map-makers also use various satellite images and computers to draw maps. Computers are able to break apart the fine details of a satellite image, store the pieces of information, and put them back together to make a map. In some instances, computers can make 3-D images of the map and even animate them. For example, scientists used computers and satellite images from Mars to create a 3-D image of Mars ice cap (Figure 2.39). The image makes you feel as if you are looking at the ice cap from the surface of Mars. When you link any type of information to a location, you can put together incredibly useful maps and images. The information could be numbers of people living in an area, types of plants or soil, locations of groundwater or levels of rainfall. As long as you can link the information to a position with a GPS receiver, you can store it in a computer for later processing and map-making. This type of mapping is called a Geographic Information System (GIS). Geologists can use GIS to make maps of natural resources. City leaders might link these resources to where people live and help plan the growth of cities or communities. Other types of data can be linked by GIS. For example, Figure 2.40 shows a map of the counties where farmers made insurance claims for crop damage in 2008. Computers have improved how maps are made. They have also increased the amount of information that can be displayed. During the 21st century, computers will be used more and more in mapping. "
Satellites can be used to track the paths of hurricanes.,(A) true (B) false,A,"To understand what satellites can do, lets look at an example. One of the deadliest hurricanes in United States history hit Galveston, Texas in 1900. The storm was first spotted at sea on Monday, August 27th , 1900. It was a tropical storm when it hit Cuba on September 3rd . By September 8th , it had intensified to a hurricane over the Gulf of Mexico. It came ashore at Galveston (Figure 2.34). Because there was not advanced warning, more than 8000 people lost their lives. Today, we have satellites with many different types of instruments that orbit the Earth. With these satellites, satellites can see hurricanes form at sea. They can follow hurricanes as they move from far out in the oceans to shore. Weather forecasters can warn people who live along the coasts. These advanced warning give people time to prepare for the storm. They can find a safe place or even evacuate the area, which helps save lives. "
All satellites orbit Earth from east to west.,(A) true (B) false,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
Communications satellites have polar orbits.,(A) true (B) false,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
A polar orbit is a shorter orbit than a geostationary orbit.,(A) true (B) false,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
Some weather satellites have geostationary orbits.,(A) true (B) false,A,"A satellite in a geostationary orbit flies above the planet at a distance of 36,000 km. It takes 24 hours to complete one orbit. The satellite and the Earth both complete one rotation in 24 hours. This means that the satellite stays over the same spot. Weather satellites use this type of orbit to observe changing weather conditions over a region. Communications satellites, like satellite TV, use this type of orbit to keep communications going full time. "
GPS can only be done with a minimum of 4 satellites.,(A) true (B) false,A,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
Polar orbits are closer to Earth than geostationary orbits.,(A) true (B) false,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
Satellites in polar orbits always remain over Earths north or south pole.,(A) true (B) false,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
GIS stands for Geostationary Information System.,(A) true (B) false,B,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
Satellites identify vegetation by the color of light it reflects.,(A) true (B) false,A,"Dozens of satellites collect data about the Earth. One example is NASAs Landsat satellites. These satellites make detailed images of Earths continents and coastal areas. Other satellites study the oceans, atmosphere, polar ice sheets, and other Earth systems. This data helps us to monitor climate change. Other long-term changes in the planet are also best seen from space. Satellite images help scientists understand how Earths systems affect one another. Different satellites monitor different wavelengths of energy, as in Figure 23.19. "
Computers increase the accuracy of maps made from satellite images and satellite data.,(A) true (B) false,A,"Prior to the late 20th and early 21st centuries, mapmakers sent people out in the field to determine the boundaries and locations for various features for maps. State or county borders were used to mark geological features. Today, people in the field use GPS receivers to mark the locations of features. Map-makers also use various satellite images and computers to draw maps. Computers are able to break apart the fine details of a satellite image, store the pieces of information, and put them back together to make a map. In some instances, computers can make 3-D images of the map and even animate them. For example, scientists used computers and satellite images from Mars to create a 3-D image of Mars ice cap (Figure 2.39). The image makes you feel as if you are looking at the ice cap from the surface of Mars. When you link any type of information to a location, you can put together incredibly useful maps and images. The information could be numbers of people living in an area, types of plants or soil, locations of groundwater or levels of rainfall. As long as you can link the information to a position with a GPS receiver, you can store it in a computer for later processing and map-making. This type of mapping is called a Geographic Information System (GIS). Geologists can use GIS to make maps of natural resources. City leaders might link these resources to where people live and help plan the growth of cities or communities. Other types of data can be linked by GIS. For example, Figure 2.40 shows a map of the counties where farmers made insurance claims for crop damage in 2008. Computers have improved how maps are made. They have also increased the amount of information that can be displayed. During the 21st century, computers will be used more and more in mapping. "
The higher above Earth that a satellite orbits the smaller the view it is able to see.,(A) true (B) false,B,Satellites orbit high above the Earth in several ways. Different orbits are important for viewing different things about the planet. 
Satellites can help you locate your precise position on Earths surface.,(A) true (B) false,A,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
A GPS receiver detects lines of latitude and longitude.,(A) true (B) false,B,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
Any type of information that can be linked with locations can be used to make a map.,(A) true (B) false,A,"Prior to the late 20th and early 21st centuries, mapmakers sent people out in the field to determine the boundaries and locations for various features for maps. State or county borders were used to mark geological features. Today, people in the field use GPS receivers to mark the locations of features. Map-makers also use various satellite images and computers to draw maps. Computers are able to break apart the fine details of a satellite image, store the pieces of information, and put them back together to make a map. In some instances, computers can make 3-D images of the map and even animate them. For example, scientists used computers and satellite images from Mars to create a 3-D image of Mars ice cap (Figure 2.39). The image makes you feel as if you are looking at the ice cap from the surface of Mars. When you link any type of information to a location, you can put together incredibly useful maps and images. The information could be numbers of people living in an area, types of plants or soil, locations of groundwater or levels of rainfall. As long as you can link the information to a position with a GPS receiver, you can store it in a computer for later processing and map-making. This type of mapping is called a Geographic Information System (GIS). Geologists can use GIS to make maps of natural resources. City leaders might link these resources to where people live and help plan the growth of cities or communities. Other types of data can be linked by GIS. For example, Figure 2.40 shows a map of the counties where farmers made insurance claims for crop damage in 2008. Computers have improved how maps are made. They have also increased the amount of information that can be displayed. During the 21st century, computers will be used more and more in mapping. "
U.S. government agency that has launched a fleet of scientific satellites,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,F,"The National Aeronautics and Space Administration (NASA) has launched a fleet of satellites to study the Earth (Figure 2.36). The satellites are operated by several government agencies, including NASA, the National Oceano- graphic and Atmospheric Administration (NOAA), and the United States Geological Survey (USGS). By using different types of scientific instruments, satellites make many kinds of measurements of the Earth. Some satellites measure the temperatures of the land and oceans. Some record amounts of gases in the atmosphere, such as water vapor and carbon dioxide. Some measure their height above the oceans very precisely. From this information, they can measure sea level. Some measure the ability of the surface to reflect various colors of light. This information tells us about plant life. Some examples of the images from these types of satellites are shown in Figure 2.37. "
type of orbit that allows a satellite to see all of Earths surface in less than a day,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,C,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
artificial body that orbits Earth,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,D,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
system of satellites used to locate exact positions on Earths surface,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,G,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
device that detects radio signals from satellites to determine its position on Earths surface,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,B,Satellites continually orbit Earth and can be used to indicate location. A global positioning system receiver detects radio signals from at least four nearby GPS satellites. The receiver measures the time it takes for radio signals to travel from a satellite and then calculates its distance from the satellite using the speed of radio signals. By calculating distances from each of the four satellites the receiver can triangulate to determine its location. You can use a GPS meter to tell you how to get to Old Faithful. 
type of orbit that allows a satellite to stay over the same location on Earths surface,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,A,"A satellite in a geostationary orbit flies above the planet at a distance of 36,000 km. It takes 24 hours to complete one orbit. The satellite and the Earth both complete one rotation in 24 hours. This means that the satellite stays over the same spot. Weather satellites use this type of orbit to observe changing weather conditions over a region. Communications satellites, like satellite TV, use this type of orbit to keep communications going full time. "
system that links GPS information with other types of information,(A) geostationary orbit (B) GPS receiver (C) polar orbit (D) satellite (E) GIS (F) NASA (G) GPS,E,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
A weather satellite with a geostationary orbit could be used to observe,(A) changes in weather all over Earths surface (B) changing weather conditions over one location on Earths surface (C) a cold front moving across the North American continent (D) a hurricane moving across the Atlantic Ocean,B,"A satellite in a geostationary orbit flies above the planet at a distance of 36,000 km. It takes 24 hours to complete one orbit. The satellite and the Earth both complete one rotation in 24 hours. This means that the satellite stays over the same spot. Weather satellites use this type of orbit to observe changing weather conditions over a region. Communications satellites, like satellite TV, use this type of orbit to keep communications going full time. "
A satellite with a polar orbit maintains a distance from Earths surface of,(A) 3 (B) 600 kilometers (C) b 36 (D) 000 kilometers (E) c 90 (F) 000 kilometers (G) d several hundred kilometers,B,"Another useful orbit is the polar orbit (Figure 2.35). The satellite orbits at a distance of several hundred kilometers. It makes one complete orbit around the Earth from the North Pole to the South Pole about every 90 minutes. In this same amount of time, the Earth rotates only slightly underneath the satellite. So in less than a day, the satellite can see the entire surface of the Earth. Some weather satellites use a polar orbit to see how the weather is changing globally. Also, some satellites that observe the land and oceans use a polar orbit. "
U.S. government agencies that use scientific satellites to gather information include,(A) NASA (B) NOAA (C) USGS (D) all of the above,D,"The National Aeronautics and Space Administration (NASA) has launched a fleet of satellites to study the Earth (Figure 2.36). The satellites are operated by several government agencies, including NASA, the National Oceano- graphic and Atmospheric Administration (NOAA), and the United States Geological Survey (USGS). By using different types of scientific instruments, satellites make many kinds of measurements of the Earth. Some satellites measure the temperatures of the land and oceans. Some record amounts of gases in the atmosphere, such as water vapor and carbon dioxide. Some measure their height above the oceans very precisely. From this information, they can measure sea level. Some measure the ability of the surface to reflect various colors of light. This information tells us about plant life. Some examples of the images from these types of satellites are shown in Figure 2.37. "
Information gathered by scientific satellites includes,(A) land temperatures (B) ocean water levels (C) global vegetation (D) all of the above,D,"The National Aeronautics and Space Administration (NASA) has launched a fleet of satellites to study the Earth (Figure 2.36). The satellites are operated by several government agencies, including NASA, the National Oceano- graphic and Atmospheric Administration (NOAA), and the United States Geological Survey (USGS). By using different types of scientific instruments, satellites make many kinds of measurements of the Earth. Some satellites measure the temperatures of the land and oceans. Some record amounts of gases in the atmosphere, such as water vapor and carbon dioxide. Some measure their height above the oceans very precisely. From this information, they can measure sea level. Some measure the ability of the surface to reflect various colors of light. This information tells us about plant life. Some examples of the images from these types of satellites are shown in Figure 2.37. "
"To use GPS to find your location on Earths surface, you need radio signals from at least",(A) 1 satellite (B) 3 satellites (C) 4 satellites (D) 24 satellites,C,Satellites continually orbit Earth and can be used to indicate location. A global positioning system receiver detects radio signals from at least four nearby GPS satellites. The receiver measures the time it takes for radio signals to travel from a satellite and then calculates its distance from the satellite using the speed of radio signals. By calculating distances from each of the four satellites the receiver can triangulate to determine its location. You can use a GPS meter to tell you how to get to Old Faithful. 
Maps that link information on natural resources with GPS positioning information are created by,(A) computers (B) GPS receivers (C) GIS satellites (D) GPS satellites,A,"Prior to the late 20th and early 21st centuries, mapmakers sent people out in the field to determine the boundaries and locations for various features for maps. State or county borders were used to mark geological features. Today, people in the field use GPS receivers to mark the locations of features. Map-makers also use various satellite images and computers to draw maps. Computers are able to break apart the fine details of a satellite image, store the pieces of information, and put them back together to make a map. In some instances, computers can make 3-D images of the map and even animate them. For example, scientists used computers and satellite images from Mars to create a 3-D image of Mars ice cap (Figure 2.39). The image makes you feel as if you are looking at the ice cap from the surface of Mars. When you link any type of information to a location, you can put together incredibly useful maps and images. The information could be numbers of people living in an area, types of plants or soil, locations of groundwater or levels of rainfall. As long as you can link the information to a position with a GPS receiver, you can store it in a computer for later processing and map-making. This type of mapping is called a Geographic Information System (GIS). Geologists can use GIS to make maps of natural resources. City leaders might link these resources to where people live and help plan the growth of cities or communities. Other types of data can be linked by GIS. For example, Figure 2.40 shows a map of the counties where farmers made insurance claims for crop damage in 2008. Computers have improved how maps are made. They have also increased the amount of information that can be displayed. During the 21st century, computers will be used more and more in mapping. "
Satellites could be used to study global warming by measuring the,(A) amounts of gases in the atmosphere (B) temperatures of ocean water (C) sizes of polar ice caps (D) all of the above,D,"Weather satellites have been increasingly important sources of weather data since the first one was launched in 1952. Weather satellites are the best way to monitor large-scale systems, such as storms. Satellites are able to record long-term changes, such as the amount of ice cover over the Arctic Ocean in September each year. Weather satellites may observe all energy from all wavelengths in the electromagnetic spectrum. Visible light images record storms, clouds, fires, and smog. Infrared images record clouds, water and land temperatures, and features of the ocean, such as ocean currents (Figure 1.3). Click image to the left or use the URL below. URL:  Infrared data superimposed on a satellite image shows rainfall patterns in Hurricane Ernesto in 2006. "
Natural resources include,(A) wind (B) sunlight (C) living things (D) all of the above,D,"We need natural resources for just about everything we do. We need them for food and clothing, for building materials and energy. We even need them to have fun. Table 20.1 gives examples of how we use natural resources. Can you think of other ways we use natural resources? Use Vehicles Resources Rubber for tires from rubber trees Steel frames and other metal parts from minerals such as iron Example iron ore Use Electronics Resources Plastic cases from petroleum prod- ucts Glass screens from minerals such as lead Example lead ore Homes Nails from minerals such as iron Timber from trees spruce timber Jewelry Gemstones such as diamonds Minerals such as silver silver ore Food Sunlight, water, and soil Minerals such as phosphorus corn seeds in soil Clothing Wool from sheep Cotton from cotton plants cotton plants Recreation Water for boating and swimming Forests for hiking and camping pine forest Some natural resources are renewable. Others are not. It depends in part on how we use them. "
The wealthiest 20% of people in the world use what percent of the resources?,(A) 35% (B) 55% (C) 85% (D) 100%,C,"Rich nations use more natural resources than poor nations. In fact, the richest 20 percent of people use 85 percent of the worlds resources. What about the poorest 20 percent of people? They use only 1 percent of the worlds resources. You can see this unequal distribution of oil resources in Figure 20.3. Imagine a world in which everybody had equal access to resources. Some people would have fewer resources than they do now. But many people would have more. In the real world, the difference between rich and poor just keeps growing. "
Uses of natural resources include,(A) food (B) jewelry (C) clothing (D) all of the above,D,"We need natural resources for just about everything we do. We need them for food and clothing, for building materials and energy. We even need them to have fun. Table 20.1 gives examples of how we use natural resources. Can you think of other ways we use natural resources? Use Vehicles Resources Rubber for tires from rubber trees Steel frames and other metal parts from minerals such as iron Example iron ore Use Electronics Resources Plastic cases from petroleum prod- ucts Glass screens from minerals such as lead Example lead ore Homes Nails from minerals such as iron Timber from trees spruce timber Jewelry Gemstones such as diamonds Minerals such as silver silver ore Food Sunlight, water, and soil Minerals such as phosphorus corn seeds in soil Clothing Wool from sheep Cotton from cotton plants cotton plants Recreation Water for boating and swimming Forests for hiking and camping pine forest Some natural resources are renewable. Others are not. It depends in part on how we use them. "
Which of the following is a renewable resource?,(A) oil (B) natural gas (C) forests (D) coal,C,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
Minerals are used to make,(A) parts for vehicles (B) fabric for clothing (C) parts for electronics (D) two of the above,D,"Metals and gemstones are often shiny, so they catch your eye. Many minerals that we use everyday are not so noticeable. For example, the buildings on your block could not have been built without minerals. The walls in your home might use the mineral gypsum for the sheetrock. The glass in your windows is made from sand, which is mostly the mineral quartz. Talc was once commonly used to make baby powder. The mineral halite is mined for rock salt. Diamond is commonly used in drill bits and saw blades to improve their cutting ability. Copper is used in electrical wiring, and the ore bauxite is the source for the aluminum in your soda can. "
Natural resources,(A) can become unusable if they become polluted (B) are useful as long as they are not used up (C) are most valuable if they are renewable (D) none of these,D,"From a human point of view, natural resources can be classified as either renewable or nonrenewable. "
"If a forest is logged,",(A) trees can be planted and so the forest is renewable (B) trees can be planted (C) but a forest takes time to be renewed (D) c it can never be the same as it was (E) d none of these,D,"Logging removes trees that protect the ground from soil erosion. The tree roots hold the soil together and the tree canopy protects the soil from hard falling rain. Logging results in the loss of leaf litter, or dead leaves, bark, and branches on the forest floor. Leaf litter plays an important role in protecting forest soils from erosion (Figure 1.3). Logging exposes large areas of land to erosion. Much of the worlds original forests have been logged. Many of the tropical forests that remain are currently the site of logging because North America and Europe have already harvested many of their trees (Figure 1.4). Soils eroded from logged forests clog rivers and lakes, fill estuaries, and bury coral reefs. Surface mining disturbs the land (Figure 1.5) and leaves the soil vulnerable to erosion. "
Which place uses the most gasoline and diesel oil?,(A) United States (B) Europe (C) China (D) India,A,"People in the U.S. use far more energyespecially energy from oilthan people in any other nation. The bar graph in the Figure 1.2 compares the amount of oil used by the top ten oil-using nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels of oil a year. Q: How does the use of oil and other fossil fuels relate to pollution? A: Greater use of oil and other fossil fuels causes more pollution. "
Which way of conserving resources is likely to use the most energy?,(A) reusing (B) reducing (C) recycling (D) precycling,C,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
Fish can be a non-renewable resource if they,(A) contain mercury (B) are overfished (C) are no longer desired as a food source (D) none of these,B,"Some resources cant be renewed. At least, they cant be renewed fast enough to keep up with use. Fossil fuels are examples. It takes millions of years for them to form. We are using them up much more quickly. Elements that are used to produce nuclear power are other examples. They include uranium. This element is already rare. Sooner or later, it will run out. Supplies of non-renewable resources are shrinking. This makes them harder to get. Oil is a good example. Oil reserves beneath land are running out. So oil companies have started to drill for oil far out in the ocean. This costs more money. Its also more dangerous. Figure 20.2 shows an oil rig that exploded in 2010. The explosion killed 11 people. Millions of barrels of oil spilled into the water. It took months to plug the leak. "
Which items can be recycled?,(A) telephone books (B) lawn clippings (C) food scraps (D) all of the above,D,"If an item can no longer be used or reused, try to recycle it. Recycling means taking a used item, breaking it down, and reusing the components. It generally takes less energy to recycle materials than obtain new ones. Recycling also keeps waste out of landfills. Some of the items that can be recycled include: glass, paper, cardboard, plastic, aluminum, iron, steel, batteries, electronics, tires, and concrete. You can learn how some of these materials are recycled by watching this video:  . MEDIA Click image to the left or use the URL below. URL:  Even kitchen scraps and garden wastes can be recycled. They can be tossed into a compost bin, like the one in Figure 25.13. The recycled compost gradually breaks down to form rich humus that can be added to lawns and gardens to improve the soil. Encourage your family to recycle if they dont already. Even if you dont have curbside recycling where you live, there are likely to be recycling drop boxes or centers available for recycling many items. If you have recycling bins at school, be sure to use them. If not, raise the issue with your teacher or principal. You can also write a letter to the editor of your local newspaper encouraging everyone in your community to recycle. "
Which alternative for bagging groceries is the best way to conserve natural resources?,(A) Use only paper bags (B) Use only plastic bags (C) Use a mix of paper and plastic bags (D) Bring your own reusable cloth bags,D,"Reusing means to use an item again rather than throwing it away and replacing it. Items can be reused for the same purpose or for a different purpose. Generally, it takes less energy to reuse an item than to recycle it, so choose this option over recycling when you can. Here are some specific tips for reusing natural resources: Consider mending or repairing worn or broken items rather than throwing them out and replacing them. Shop with reuse in mind. You can find great buys at flea markets and resale shops. You may be able to get free items online at free-cycle sites. Youll save money as well as natural resources. You can also sell (or give away) your own reusable items. Reuse cloth shopping bags. Instead of getting new plastic or paper bags for your purchases each time you shop, take your own reusable bag to the store each time. Even little steps can add up and help save natural resources. For example, unwrap gifts carefully and youll be able to reuse the gift wrap on a package for someone else. You can also reuse writing paper that has only been used on one side. Its great for notes and shopping lists. "
Drinking bottled water is better for you and the environment.,(A) true (B) false,B,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
It is usually better to throw something away than to fix it.,(A) true (B) false,B,"You probably already know about the three Rs. They stand for reduce, reuse, and recycle. The third R recycle has caught on in a big way. Thats because its easy. There are thousands of places to drop off items such as aluminum cans for recycling. Many cities allow you to just put your recycling in a special can and put it at the curb. We havent done as well with the first two Rs reducing and reusing. But they arent always as easy as recycling. Recycling is better than making things from brand new materials. But it still takes some resources to turn recycled items into new ones. It takes no resources at all to reuse items or not buy them in the first place. "
Pollution occurs when a product is produced and when it is tossed away.,(A) true (B) false,A,"Modern agricultural practices produce a lot of pollution (Figure 1.1). Some pesticides are toxic. Dead zones grow as fertilizers drain off farmland and introduce nutrients into lakes and coastal areas. Farm machines and vehicles used to transport crops produce air pollutants. Pollutants enter the air, water, or are spilled onto the land. Moreover, many types of pollution easily move between air, water, and land. As a result, no location or organism  not even polar bears in the remote Arctic  is free from pollution. "
Your community probably recycles plastics that have certain numbers on them.,(A) true (B) false,A,"You probably already know about the three Rs. They stand for reduce, reuse, and recycle. The third R recycle has caught on in a big way. Thats because its easy. There are thousands of places to drop off items such as aluminum cans for recycling. Many cities allow you to just put your recycling in a special can and put it at the curb. We havent done as well with the first two Rs reducing and reusing. But they arent always as easy as recycling. Recycling is better than making things from brand new materials. But it still takes some resources to turn recycled items into new ones. It takes no resources at all to reuse items or not buy them in the first place. "
Soil is considered a non-renewable resource.,(A) true (B) false,B,Soil is only a renewable resource if it is carefully managed. There are many practices that can protect and preserve soil resources. 
Renewable resources cannot be overused.,(A) true (B) false,B,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
Both plastic and rubber are made from petroleum.,(A) true (B) false,B,"Some plastics contain toxic chemicals, such as bisphenol A. Plastics can also absorb organic pollutants that may be floating in the water, such as the pesticide DDT (which is banned in the U.S. but not in other nations) and some endocrine disruptors. "
Elements that are used to produce nuclear power are renewable resources.,(A) true (B) false,B,"Like fossil fuels, the radioactive element uranium can be used to generate electrical energy in power plants. This source of energy is known as nuclear energy. In a nuclear power plant, the nuclei of uranium atoms are split apart into smaller nuclei in the process of nuclear fission. This process releases a tremendous amount of energy from just a small amount of uranium. The total supply of uranium in the world is quite limited, however, and cannot be replaced once it is used up. Thats why nuclear energy is a nonrenewable resource. The use of nuclear energy also produces dangerous radioactive wastes. In addition, accidents at nuclear power plants have the potential to release large amounts of harmful radiation into the environment. Q: Why is nuclear energy often considered to be greener than energy from fossil fuels? A: Unlike energy from fossil fuels, nuclear energy doesnt produce air pollution or carbon dioxide that contributes to global climate change. "
Oil reserves beneath land are running out.,(A) true (B) false,A,"Some resources cant be renewed. At least, they cant be renewed fast enough to keep up with use. Fossil fuels are examples. It takes millions of years for them to form. We are using them up much more quickly. Elements that are used to produce nuclear power are other examples. They include uranium. This element is already rare. Sooner or later, it will run out. Supplies of non-renewable resources are shrinking. This makes them harder to get. Oil is a good example. Oil reserves beneath land are running out. So oil companies have started to drill for oil far out in the ocean. This costs more money. Its also more dangerous. Figure 20.2 shows an oil rig that exploded in 2010. The explosion killed 11 people. Millions of barrels of oil spilled into the water. It took months to plug the leak. "
When we conserve resources we also produce less trash.,(A) true (B) false,A,"How can we protect Earths natural resources? One answer is conservation. This means saving resources. We need to save resources so some will be left for the future. We also need to protect resources from pollution and overuse. When we conserve resources, we also cut down on the trash we produce. Americans throw out 340 million tons of trash each year. We throw out 2.5 million plastic bottles alone every hour! Most of what we throw out ends up in landfills. You can see a landfill in Figure 20.4. In a landfill, all those plastic bottles take hundreds of years to break down. What are the problems caused by producing so much trash? Natural resources must be used to produce the materials. Land must be given over to dump the materials. If the materials are toxic, they may cause pollution. "
We use less of fossil fuels today than we did in the 1970s.,(A) true (B) false,B,"We can reduce our use of fossil fuels in several ways: Conserve fossil fuels. For example, turning out lights when we arent using them saves electricity. Why does this help? A lot of the electricity we use comes from coal-burning power plants. Use fossil fuels more efficiently. For example, driving a fuel-efficient car lets you go farther on each gallon of gas. This can add up to a big savings in fossil fuel use. Change to alternative energy sources that produce little or no air pollution. For example, hybrid cars run on electricity that would be wasted during braking. These cars use gas only as a backup fuel. As a result, they produce just 10 percent of the air pollution produced by cars that run only on gas. Cars that run on hydrogen and produce no pollution at all have also been developed (see Figure 22.14). "
China uses more paper per person than any other country.,(A) true (B) false,B,"The United States has long been the largest emitter of greenhouse gases, with about 20% of total emissions in 2004. As a result of Chinas rapid economic growth, its emissions surpassed those of the United States in 2008. However, its also important to keep in mind that the United States has only about one-fifth the population of China. Whats the significance of this? The average United States citizen produces far more greenhouse gas emissions than the average Chinese person. "
It costs more to recycle resources than to use new resources.,(A) true (B) false,B,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
Recycling used products is the same as reusing them.,(A) true (B) false,B,"Now we move on to recycle. Sometimes it may be difficult to understand the differences between reusing and recycling. Recycling involves processing used materials in order to make them suitable for other uses. That usually means taking a used item, breaking it down, and reusing the pieces. Even though recycling requires extra energy, it does often make use of items which are broken, worn out, or cannot be reused. The things that are commonly recycled include: Batteries. Biodegradable waste. Electronics. Iron and steel. Aluminum ( Figure 1.2). Glass. Paper. Plastic. Textiles, such as clothing. Timber. Tires. Each type of recyclable requires a different recycling technique. Here are some things you can do to recycle in your home, school, or community: Laws can also be created to make sure people and companies reduce, reuse, and recycle. Individuals can vote for leaders who stand for sustainable ecological practices. They can also tell their leaders to make wise use of natural resources. You can also influence companies. If you and your family only buy from companies and restaurants that support recycling or eco-friendly packaging, then other companies will also change to be more environmentally friendly. "
Recycled plastic water bottles can be made into t-shirts.,(A) true (B) false,A,"Many things can be recycled. The materials in them can be reused in new products. For example, plastic water bottles can be recycled. The recycled material can be made into t-shirts! Old phone books can also be recycled and made into textbooks. When you shop for new products, look for those that are made of recycled materials (see Figure 20.8). Even food scraps and lawn waste can be recycled. They can be composted and turned into humus for the garden. At most recycling centers, you can drop off metal cans, cardboard and paper products, glass containers, and plastic bottles. Recycling stations like the one in Figure 20.9 are common. Curbside recycling usually takes these items too. Do you know how to recycle in your community? Contact your local solid waste authority to find out. If you dont already recycle, start today. Its a big way you can help the planet! "
example of a renewable resource,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,E,"Renewable resources can be renewed as they are used. An example is timber, which comes from trees. New trees can be planted to replace those that are cut down. Sunlight is a renewable resource. It seems we will never run out of that! Just because a resource is renewable, it doesnt mean we should use it carelessly. If we arent careful, we can pollute resources. Then they may no longer be fit for use. Water is one example. If we pollute a water source it may not be usable for drinking, bathing or any other type of use. We can also overuse resources that should be renewable. In this case the resources may not be able to recover. For example, fish are renewable resources. Thats because they can reproduce and make more fish. But water pollution and overfishing can cause them to die out if their population becomes too low. Figure 20.1 shows another example. "
saving resources,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,C,"Reducing resource use means just what it says using fewer resources. There are lots of ways to reduce our use of resources. Buy durable goods. Choose items that are well made so they will last longer. Youll buy fewer items in the long run, so youll save money as well as resources. Thats a win-win! Repair rather than replace. Fix your bike rather than buying a new one. Sew on a button instead of buying a new shirt. Youll use fewer resources and save money. Buy only what you need. Dont buy a gallon of milk if you can only drink half of it before it spoils. Instead, buy a half gallon and drink all of it. You wont be wasting resources (or money!). Buy local. For example, buy local produce at a farmers market, like the one in Figure 20.5. A lot of resources are saved by not shipping goods long distances. Products bought at farmers markets use less packaging, too! About a third of what we throw out is packaging. Try to buy items with the least amount of packaging. For example, buy bulk items instead of those that are individually wrapped. Also, try to select items with packaging that can be reused or recycled. This is called precycling. Pop cans and plastic water bottles, for example, are fairly easy to recycle. Some types of packaging are harder to recycle. You can see examples in Figure 20.6. If it cant be reused or recycled, its a waste of resources. Many plastics: The recycling symbol on the bottom of plastic containers shows the type of plastic they contain. Numbers 1 and 2 are easier to recycle than higher numbers. Mixed materials: Packaging that contains more than one material may be hard to recycle. This carton is made mostly of cardboard. But it has plastic around the opening. "
any natural resource that will not run out if we use it wisely,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,D,"A resource is renewable if it is remade by natural processes at the same rate that humans use it up. Sunlight and wind are renewable resources because they will not be used up ( Figure 1.1). The rising and falling of ocean tides is another example of a resource in unlimited supply. A sustainable resource is a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs. People can sustainably harvest wood, cork, and bamboo. Farmers can also grow crops sustainably by not planting the same crop in their soil year after year. Planting the same crop each year can remove nutrients from the soil. This means that wood, cork, bamboo, and crops can be sustainable resources. "
anything in nature that humans need,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,A,"The increased numbers of people have other impacts on the planet. Humans do not just need food. They also need clean water, secure shelter, and a safe place for their wastes. These needs are met to different degrees in different nations and among different socioeconomic classes of people. For example, about 1.2 billion of the worlds people do not have enough clean water for drinking and washing each day (Figure 1.2). "
buying items with reusable or recyclable packaging,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,F,"Reusing means to use an item again rather than throwing it away and replacing it. Items can be reused for the same purpose or for a different purpose. Generally, it takes less energy to reuse an item than to recycle it, so choose this option over recycling when you can. Here are some specific tips for reusing natural resources: Consider mending or repairing worn or broken items rather than throwing them out and replacing them. Shop with reuse in mind. You can find great buys at flea markets and resale shops. You may be able to get free items online at free-cycle sites. Youll save money as well as natural resources. You can also sell (or give away) your own reusable items. Reuse cloth shopping bags. Instead of getting new plastic or paper bags for your purchases each time you shop, take your own reusable bag to the store each time. Even little steps can add up and help save natural resources. For example, unwrap gifts carefully and youll be able to reuse the gift wrap on a package for someone else. You can also reuse writing paper that has only been used on one side. Its great for notes and shopping lists. "
example of a nonrenewable resource,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,B,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
any natural resource that will run out if we keep using it,(A) natural resource (B) fossil fuel (C) conservation (D) renewable resource (E) water (F) precycling (G) nonrenewable resource,G,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
Saving energy in industry is,(A) possible if equipment is designed to be efficient (B) possible if new materials are used (C) not possible (D) since little energy is used (E) d none of these,A,We can reduce our use of energy resources and the pollution they cause by conserving energy. Conservation means saving resources by using them more efficiently or not using them at all. Figure 17.24 shows several ways that people can conserve energy in their daily lives. You can find more energy-saving tips at the URL below. What do you do to save energy? What else could you do? 
"In the U.S., more energy is used for transportation than for any other single purpose.",(A) true (B) false,B,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
Nonrenewable energy resources used in the U.S. include nuclear energy.,(A) true (B) false,A,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
What are some ways residences can use less energy?,(A) Turn off lights when not in use (B) Only run appliances when necessary (C) Use a fan instead of an air conditioner (D) All of the above,D,"There are many ways to use less energy. Table 20.2 lists some of them. Can you think of other ways to use less energy? For example, how might schools use less energy? Use of Energy Transportation How to Use Less Plan ahead to reduce the number of trips you make. Take a bus or train instead of driving. Walk or bike rather than ride. Home Unplug appliances when not in use. Turn off lights when you leave a room. Put on a sweater instead of turning up the heat. Run the dishwasher and washing machine only when full. "
The renewable energy resource that is used most in the U.S. is solar energy.,(A) true (B) false,B,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
What person of the energy use in the United States is used for transportation?,(A) 14% (B) 28% (C) 45% (D) 67%,B,"Much of the energy used in the U.S. is used for transportation. You can conserve transportation energy in several ways. For example, you can: plan ahead to avoid unnecessary trips. take public transit such as subways (see Figure 1.1) instead of driving. drive an energy-efficient vehicle when driving is the only way to get there. Q: What are some other ways you could save energy in transportation? A: You could carpool to save transportation energy. Even if you carpool with just one other person, thats one less vehicle on the road. For short trips, you could ride a bike or walk to you destination. The extra exercise is another benefit of using your own muscle power to get where you need to go. "
Solar energy usually must be transported long distances to be useful.,(A) true (B) false,B,"Solar energy has many benefits. It is extremely abundant, widespread, and will never run out. But there are problems with the widespread use of solar power. Sunlight must be present. Solar power is not useful in locations that are often cloudy or dark. However, storage technology is being developed. The technology needed for solar power is still expensive. An increase in interested customers will provide incentive for companies to research and develop new technologies and to figure out how to mass-produce existing technologies (Figure 1.3). Solar panels require a lot of space. Fortunately, solar panels can be placed on any rooftop to supply at least some of the power required for a home or business. This experimental car is one example of the many uses that engineers have found for solar energy. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
The cost of an energy source depends on,(A) the cost of equipment needed to harness it (B) the cost of transporting it (C) its energy efficiency (D) all of these,D,"Some of the resources we depend on the most are energy resources. Whether its powering our lights and computers, heating our homes, or providing energy for cars and other vehicles, its hard to imagine what our lives would be like without a constant supply of energy. "
The purpose of solar panels is to prevent sunlight from overheating a home.,(A) true (B) false,B,"Solar energy is used to heat homes and water, and to make electricity. Scientists and engineers have many ways to get energy from the Sun (Figure 5.9). One is by using solar cells. Solar cells are devices that turn sunlight directly into electricity. Lots of solar cells make up an individual solar panel. You may have seen solar panels on roof tops. The Suns heat can also be trapped in your home by using south facing windows and good insulation. "
Conserving energy,(A) is expensive because you have to buy special equipment (B) reduces costs because you create energy from less expensive sources (C) reduces costs because you use less energy (D) All of these,C,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
Most nonrenewable energy resources will last thousands of years if we conserve them.,(A) true (B) false,B,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
Collecting sunlight for solar energy requires solar energy power plants.,(A) true (B) false,B,"Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. "
You can save more energy by unplugging appliances than just turning them off.,(A) true (B) false,A,"Many people waste energy at home, so a lot of energy can be saved there as well. What can you do to conserve energy? You can: turn off lights and unplug appliances and other electrical devices when not in use. use energy-efficient light bulbs and appliances. turn the thermostat down in winter and up in summer. Q: How can you tell which light bulbs and appliances use less energy? "
A car uses gasoline more efficiently if it is driven faster than 55 mi/hr.,(A) true (B) false,B,"Gasoline is a concentrated resource. It contains a large amount of energy for its weight. This is important because the more something weighs, the more energy is needed to move it. If gasoline could only provide a little energy, a car would have to carry a lot of it to be able to travel very far. Or the car would need to be filled up frequently. So a highly concentrated energy resource is a practical fuel to power cars and other forms of transportation. Lets consider how gasoline powers a car. As gasoline burns, it releases most of its energy as heat. It also releases carbon dioxide gas and water vapor. The heat makes the gases expand. This forces the pistons inside the engine to move. The engine makes enough power to move the car. "
You can save electricity by using compact fluorescent light bulbs.,(A) true (B) false,A,"Many people waste energy at home, so a lot of energy can be saved there as well. What can you do to conserve energy? You can: turn off lights and unplug appliances and other electrical devices when not in use. use energy-efficient light bulbs and appliances. turn the thermostat down in winter and up in summer. Q: How can you tell which light bulbs and appliances use less energy? "
"If the cost of oil goes up, sources that were too expensive to extract may become economical.",(A) true (B) false,A,"Net energy is the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available. For example, every 5 barrels of oil that are made available for use require 1 barrel for extracting and refining the petroleum. What is the net energy from this process? About 4 barrels (5 barrels minus 1 barrel). What happens if the energy needed to extract and refine oil increases? Why might that happen? The energy cost of an energy resource increases when the easy deposits of that resource have already been consumed. For example, if all the nearshore petroleum in a region has been extracted, more costly drilling must take place further offshore (Figure 1.1). If the energy cost of obtaining energy increases, the resource will be used even faster. Offshore drilling is taking place in deeper water than before. It takes a lot of energy to build a deep drilling platform and to run it. "
fuel that is refined from petroleum,(A) industry (B) gasoline (C) solar energy (D) refinery (E) petroleum,B,"Most of the compounds that come out of the refining process are fuels, such as gasoline, diesel, and heating oil. Because these fuels are rich sources of energy and can be easily transported, oil provides about 90% of the energy used for transportation around the world. The rest of the compounds from crude oil are used for waxes, plastics, fertilizers, and other products. Gasoline is in a convenient form for use in cars and other transportation vehicles. In a car engine, the burned gasoline mostly turns into carbon dioxide and water vapor. The fuel releases most of its energy as heat, which causes the gases to expand. This creates enough force to move the pistons inside the engine and to power the car. Refineries like this one separate crude oil into many useful fuels and other chemi- cals. Click image to the left or use the URL below. URL: "
"To increase energy efficiency, be sure that equipment is running well.",(A) true (B) false,A,"We can get more work out of the energy we use. Table 20.3 show some ways to use energy more efficiently. By getting more bang for the buck, we wont need to use as much energy overall. Does your family use energy efficiently? How could you find out? Use of Energy More Efficient Use Another way to use energy more efficiently is with Energy Star appliances. They carry the Energy Star logo, shown in Figure 20.14. To be certified as Energy Star, the appliance must use less energy. Energy Star appliances save a lot of energy over their lifetime. What if millions of households used Energy Star appliances? How much energy would it save? "
energy resource that is used more than any other in the U.S.,(A) industry (B) gasoline (C) solar energy (D) refinery (E) petroleum,E,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
Conserving resources cuts down on trash.,(A) true (B) false,A,"How can we protect Earths natural resources? One answer is conservation. This means saving resources. We need to save resources so some will be left for the future. We also need to protect resources from pollution and overuse. When we conserve resources, we also cut down on the trash we produce. Americans throw out 340 million tons of trash each year. We throw out 2.5 million plastic bottles alone every hour! Most of what we throw out ends up in landfills. You can see a landfill in Figure 20.4. In a landfill, all those plastic bottles take hundreds of years to break down. What are the problems caused by producing so much trash? Natural resources must be used to produce the materials. Land must be given over to dump the materials. If the materials are toxic, they may cause pollution. "
plant that separates petroleum into different products,(A) industry (B) gasoline (C) solar energy (D) refinery (E) petroleum,D,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
example of a renewable energy resource,(A) industry (B) gasoline (C) solar energy (D) refinery (E) petroleum,C,"Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table 17.1. Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. here? Renewable Energy Resource Sunlight The energy in sunlight, or solar energy, can be used to heat homes. It can also be used to produce electricity in solar cells. However, solar energy may not be practical in areas that are often cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water When water falls downhill, its potential energy is con- verted to kinetic energy that can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream and reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air, so it has kinetic energy that can do work. Remember the wind turbines that opened this chapter? Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy and unattractive in the landscape. Water flowing through Hoover dam between Arizona and Nevada generates electricity for both of these states and also by southern California. The dam spans the Colorado River. This old-fashioned windmill captures wind energy that is used for pumping water out of a well. Windmills like this one have been used for centuries. Renewable Energy Resource Biomass The stored chemical energy of trees and other plants is called biomass energy. When plant materials are burned, they produce thermal energy that can be used for heating, cooking, or generating electricity. Biomassespecially woodis an important energy source in countries where most people cant afford fossil fuels. Some plants can also be used to make ethanol, a fuel that is added to gasoline. Ethanol produces less pollution than gasoline, but large areas of land are needed to grow the plants needed to make it. Geothermal Heat below Earths surfacecalled geothermal en- ergycan be used to produce electricity. A power plant pumps water underground where it is heated. Then it pumps the water back to the plant and uses its thermal energy to generate electricity. On a small scale, geothermal energy can be used to heat homes. Installing a geothermal system can be very costly, how- ever, because of the need to drill through underground rocks. Example This large machine is harvesting and grinding plants to be used for biomass energy. This geothermal power plant is located in Italy where hot magma is close to the surface. "
The best energy source would be one that supplies a lot of energy and takes a lot of energy to make it,(A) true (B) false,B,"Energy provides the ability to move or change matter from one state to another (for example, from solid to liquid). Every living thing needs energy to live and grow. Your body gets its energy from food, but that is only a small part of the energy you use every day. Cooking your food takes energy, and so does keeping it cold in the refrigerator or the freezer. The same is true for heating or cooling your home. Whether you are turning on a light in the kitchen or riding in a car to school, you are using energy. Billions of people all around the world use energy, so there is a huge demand for resources to provide all of this energy. Why do we need so much energy? The main reason is that almost everything that happens on Earth involves energy. "
Individuals can only do a little to increase energy efficiency because most energy is used by industry.,(A) true (B) false,B,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
largest single use of energy in the U.S.,(A) industry (B) gasoline (C) solar energy (D) refinery (E) petroleum,A,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
Which of the following uses the most total energy in the U.S.?,(A) stores (B) homes (C) businesses (D) shopping malls,B,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
"Of all the energy used in the U.S., industrial uses account for",(A) 17 percent (B) 21 percent (C) 28 percent (D) 33 percent,D,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
The U.S. depends for energy mainly on,(A) wind (B) sunlight (C) fossil fuels (D) flowing water,C,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
Fossil fuels include,(A) coal (B) petroleum (C) natural gas (D) all of the above,D,"Fossil fuels are mixtures of hydrocarbons that formed over millions of years from the remains of dead organisms. They include petroleum (commonly called oil), natural gas, and coal. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes. You can see examples of their use in Figure 17.19. Fossil fuels contain stored chemical energy that came originally from the sun. Ancient plants changed energy in "
The first step in obtaining and using fossil fuels is,(A) changing fossil fuels to different forms of energy (B) removing fossil fuels from the ground (C) finding fossil fuel reserves (D) refining fossil fuels,C,"Can you name some fossils? How about dinosaur bones or dinosaur footprints? Animal skeletons, teeth, shells, coprolites (otherwise known as feces), or any other remains or traces from a living creature that becomes rock is a fossil. The same processes that formed these fossils also created some of our most important energy resources, fossil fuels. Coal, oil, and natural gas are fossil fuels. Fossil fuels come from living matter starting about 500 million years ago. Millions of years ago, plants used energy from the Sun to form sugars, carbohydrates, and other energy-rich carbon compounds. As plants and animals died, their remains settled on the ground on land and in swamps, lakes, and seas (Figure 1.1). Over time, layer upon layer of these remains accumulated. Eventually, the layers were buried so deeply that they were crushed by an enormous mass of earth. The weight of this earth pressing down on these plant and animal remains created intense heat and pressure. After millions of years of heat and pressure, the material in these layers turned into chemicals called hydrocarbons (Figure 1.2). Hydrocarbons are made of carbon and hydrogen atoms. This molecule with one carbon and four hydrogen atoms is methane. Hydrocarbons can be solid, liquid, or gaseous. The solid form is what we know as coal. The liquid form is petroleum, or crude oil. Natural gas is the gaseous form. The solar energy stored in fossil fuels is a rich source of energy. Although fossil fuels provide very high quality energy, they are non-renewable. Click image to the left or use the URL below. URL: "
Petroleum is separated into different products by,(A) freezing (B) melting (C) cooling (D) heating,D,"In order to be collected, the oil must be located between a porous rock layer and an impermeable layer (Figure 1.1). Trapped above the porous rock layer and beneath the impermeable layer, the oil will remain between these layers until it is extracted from the rock. Oil (red) is found in the porous rock layer (yellow) and trapped by the impermeable layer (brown). The folded structure has allowed the oil to pool so a well can be drilled into the reservoir. To separate the different types of hydrocarbons in crude oil for different uses, the crude oil must be refined in refineries like the one shown in Figure 1.2. Refining is possible because each hydrocarbon in crude oil boils at a different temperature. When the oil is boiled in the refinery, separate equipment collects the different compounds. "
"Obtaining, refining, and transporting oil require energy. For every 5 barrels of oil we use, the oil required for these purposes is",(A) 1 barrel (B) 2 barrels (C) 3 barrels (D) 4 barrels,A,"Net energy is the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available. For example, every 5 barrels of oil that are made available for use require 1 barrel for extracting and refining the petroleum. What is the net energy from this process? About 4 barrels (5 barrels minus 1 barrel). What happens if the energy needed to extract and refine oil increases? Why might that happen? The energy cost of an energy resource increases when the easy deposits of that resource have already been consumed. For example, if all the nearshore petroleum in a region has been extracted, more costly drilling must take place further offshore (Figure 1.1). If the energy cost of obtaining energy increases, the resource will be used even faster. Offshore drilling is taking place in deeper water than before. It takes a lot of energy to build a deep drilling platform and to run it. "
"Regarding water use, developing nations use",(A) a greater percentage for industry (B) more for agriculture than for industry (C) more for household uses than any other category (D) a greater percentage for agriculture,B,"Richer nations can drill deep wells, build large dams or supply people with water in other ways. In these countries, just about everyone has access to clean running water in their homes. Its no surprise that people in these countries also use the most water. In poorer nations, there is little money to develop water supplies. Look at the people in Figure 21.6. These people must carry water home in a bucket from a distant pump. "
Municipal use of water refers to water that is used for,(A) manufacturing (B) growing crops (C) raising livestock (D) none of the above,D,"Figure 21.1 shows how people use water worldwide. The greatest use is for agriculture and then industry. Municipal use is last, but is also important. Municipal use refers to water used by homes and businesses in communities. "
Irrigation water may cause,(A) soil to become too salty for plants (B) pesticides to enter groundwater (C) a lot of water to be wasted (D) all of the above,D,"Many crops are grown where there isnt enough rainfall for plants to thrive. For example, crops are grown in deserts of the American southwest. How is this possible? The answer is irrigation. Irrigation is any way of providing extra water to plants. Most of the water used in agriculture is used for irrigation. Livestock also use water, but they use much less. Irrigation can waste a lot of water. The type of irrigation shown in Figure 21.2 is the most wasteful. The water is sprayed into the air and then falls to the ground. But much of the water never reaches the crops. Instead, it evaporates in the air or runs off the fields. Irrigation water may cause other problems. The water may dissolve agricultural chemicals such as pesticides. When the water soaks into the ground, the dissolved chemicals do, too. They may enter groundwater or run off into rivers or lakes. Salts in irrigation water can also collect in the soil. The soil may get too salty for plants to grow. "
Recreational uses of water include,(A) irrigating golf courses (B) kayaking (C) scuba diving (D) all of these,D,"People love water for swimming, fishing, boating, river rafting, and other activates. Even activities such as golf, where there may not be any standing water, require plenty of water to make the grass on the course green. Despite its value, the amount of water that most recreational activities use is low: less than 1% of all the water we use. Many recreational water uses are non-consumptive including swimming, fishing, and boating. Golf courses are the biggest recreational water consumer since they require large amounts for irrigation, especially because many courses are located in warm, sunny, desert regions where water is scarce and evaporation is high. "
Almost a quarter of the water used worldwide is used by,(A) farms (B) factories (C) businesses (D) households,B,Almost a quarter of the water used worldwide is used in industry. Industries use water for many purposes. Chemical processes need a lot of water. Water is used to generate electricity. An important way that industries use water is to cool machines and power plants. 
Agricultural chemicals,(A) may enter groundwater (B) evaporate into the air (C) stay on the plants they target (D) all of these,A,"The Green Revolution has allowed the addition of billions of people to the population in the past few decades. The Green Revolution has improved agricultural productivity by: Improving crops by selecting for traits that promote productivity; recently, genetically engineered crops have been introduced. Increasing the use of artificial fertilizers and chemical pesticides. About 23 times more fertilizer and 50 times more pesticides are used around the world than were used just 50 years ago (Figure 1.5). Agricultural machinery: plowing, tilling, fertilizing, picking, and transporting are all done by machines. About 17% of the energy used each year in the United States is for agriculture. Increasing access to water. Many farming regions depend on groundwater, which is not a renewable resource. Some regions will eventually run out of this water source. Currently about 70% of the worlds fresh water is used for agriculture. Rows of a single crop and heavy ma- chinery are normal sights for modern day farms. The Green Revolution has increased the productivity of farms immensely. A century ago, a single farmer produced enough food for 2.5 people, but now a farmer can feed more than 130 people. The Green Revolution is credited for feeding 1 billion people that would not otherwise have been able to live. "
Water is lost for human use if it,(A) infiltrates into the ground (B) enters a stream (C) becomes polluted (D) all of these,C,"Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water? You lose water in your breath each time you exhale. You lose water in urine. You lose water in sweat, especially if you are active in warm weather. The boy in Figure 17.5 is taking a water break while playing outside on a hot day. If he doesnt take in enough water to replace the water lost in sweat, he may become dehydrated. Symptoms of dehydration include dry mouth, headache, and dizziness. Dehydration can be very serious. It can even cause death. "
"In industry, water is used for",(A) cooling machines (B) chemical reactions (C) purifying municipal sewage (D) two of the above,D,Almost a quarter of the water used worldwide is used in industry. Industries use water for many purposes. Chemical processes need a lot of water. Water is used to generate electricity. An important way that industries use water is to cool machines and power plants. 
The main cause of disease and death in young children worldwide is,(A) food scarcity (B) water scarcity (C) water pollution (D) none of the above,C,"Waterborne disease caused by unsafe drinking water is the leading cause of death for children under the age of five in many nations and a cause of death and illness for many adults. About 88% of all diseases are caused by drinking unsafe water (Figure 1.1). Throughout the world, more than 14,000 people die every day from waterborne diseases, such as cholera, and many of the worlds hospital beds are occupied by patients suffering from a waterborne disease. Guinea worm is a serious problem in parts of Africa that is being eradicated. Learn what is being done to decrease the number of people suffering from this parasite at the video below. Click image to the left or use the URL below. URL: "
The amount of water available to a population depends on,(A) rainfall (B) the money available to develop water supplies (C) political agreements (D) all of these,D,"Water scarcity can have dire consequences for the people, the economy, and the environment. Without adequate water, crops and livestock dwindle and people go hungry. Industry, construction, and economic development is halted, causing a nation to sink further into poverty. The risk of regional conflicts over scarce water resources rises. People die from diseases, thirst, or even in war over scarce resources. Californias population is growing by hundreds of thousands of people a year, but much of the state receives as much annual rainfall as Morocco. With fish populations crashing, global warming, and the demands of the countrys largest agricultural industry, the pressures on our water supply are increasing. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Which of the following human actions increases the risk of drought?,(A) cutting down trees (B) irrigating farmland (C) building golf courses (D) polluting water with wastes,A,"Droughts occur when a region experiences unusually low precipitation for months or years (Figure 1.2). Periods of drought may create or worsen water shortages. Human activities can contribute to the frequency and duration of droughts. For example, deforestation keeps trees from returning water to the atmosphere by transpiration; part of the water cycle becomes broken. Because it is difficult to predict when droughts will happen, it is difficult for countries to predict how serious water shortages will be each year. Extended periods with lower than normal rainfall cause droughts. "
A lot of irrigation water is wasted because it,(A) evaporates in the air (B) runs off the field (C) soaks into the soil (D) two of the above,D,"Many crops are grown where there isnt enough rainfall for plants to thrive. For example, crops are grown in deserts of the American southwest. How is this possible? The answer is irrigation. Irrigation is any way of providing extra water to plants. Most of the water used in agriculture is used for irrigation. Livestock also use water, but they use much less. Irrigation can waste a lot of water. The type of irrigation shown in Figure 21.2 is the most wasteful. The water is sprayed into the air and then falls to the ground. But much of the water never reaches the crops. Instead, it evaporates in the air or runs off the fields. Irrigation water may cause other problems. The water may dissolve agricultural chemicals such as pesticides. When the water soaks into the ground, the dissolved chemicals do, too. They may enter groundwater or run off into rivers or lakes. Salts in irrigation water can also collect in the soil. The soil may get too salty for plants to grow. "
All forms of life need water to survive.,(A) true (B) false,A,"Plants and animals depend on water to live. They also play a role in the water cycle. Plants take up water from the soil and release large amounts of water vapor into the air through their leaves (Figure 1.3), a process known as transpiration. "
We can live longer without water than we can without food.,(A) true (B) false,B,"Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water? You lose water in your breath each time you exhale. You lose water in urine. You lose water in sweat, especially if you are active in warm weather. The boy in Figure 17.5 is taking a water break while playing outside on a hot day. If he doesnt take in enough water to replace the water lost in sweat, he may become dehydrated. Symptoms of dehydration include dry mouth, headache, and dizziness. Dehydration can be very serious. It can even cause death. "
Irrigation may add unwanted chemicals to groundwater.,(A) true (B) false,A,"Many crops are grown where there isnt enough rainfall for plants to thrive. For example, crops are grown in deserts of the American southwest. How is this possible? The answer is irrigation. Irrigation is any way of providing extra water to plants. Most of the water used in agriculture is used for irrigation. Livestock also use water, but they use much less. Irrigation can waste a lot of water. The type of irrigation shown in Figure 21.2 is the most wasteful. The water is sprayed into the air and then falls to the ground. But much of the water never reaches the crops. Instead, it evaporates in the air or runs off the fields. Irrigation water may cause other problems. The water may dissolve agricultural chemicals such as pesticides. When the water soaks into the ground, the dissolved chemicals do, too. They may enter groundwater or run off into rivers or lakes. Salts in irrigation water can also collect in the soil. The soil may get too salty for plants to grow. "
Large irrigation systems may waste a lot of water.,(A) true (B) false,A,Irrigation is the single biggest use of water. Overhead irrigation wastes a lot of water. Drip irrigation wastes a lot less. Figure 21.19 shows a drip irrigation system. Water pipes run over the surface of the ground. Tiny holes in the pipes are placed close to each plant. Water slowly drips out of the holes and soaks into the soil around the plants. Very little of the water evaporates or runs off the ground. 
Water can be used to generate electricity.,(A) true (B) false,A,"Moving water has energy (Figure 5.10). That energy is used to make electricity. Hydroelectric power harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the worlds electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare. "
Water scarcity is not a problem since 70% of Earth is covered by water.,(A) true (B) false,B,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
More than 70 percent of Earths surface is covered with water.,(A) true (B) false,A,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
Glaciers are a source of fresh water in some locations.,(A) true (B) false,A,"In regions where summers are long and dry, melting glaciers in mountain regions provide an important source of water for organisms and often for nearby human populations. Click image to the left or use the URL below. URL: "
Most people in the world have enough clean fresh water.,(A) true (B) false,B,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
Most of the fresh water on Earth is under the ground.,(A) true (B) false,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
"By the year 2025, only one-quarter of the worlds people will have enough clean water.",(A) true (B) false,B,"Water scarcity is a problem now and will become an even larger problem in the future as water sources are reduced or polluted and population grows. In 1995, about 40% of the worlds population faced water scarcity. Scientists estimate that by the year 2025, nearly half of the worlds people wont have enough water to meet their daily needs. Nearly one-quarter of the worlds people will have less than 500 m3 of water to use in an entire year. That amount is less water in a year than some people in the United States use in one day. Some regions have very little rainfall per month. "
"In poorer countries, many young children die from waterborne diseases.",(A) true (B) false,A,"Waterborne disease caused by unsafe drinking water is the leading cause of death for children under the age of five in many nations and a cause of death and illness for many adults. About 88% of all diseases are caused by drinking unsafe water (Figure 1.1). Throughout the world, more than 14,000 people die every day from waterborne diseases, such as cholera, and many of the worlds hospital beds are occupied by patients suffering from a waterborne disease. Guinea worm is a serious problem in parts of Africa that is being eradicated. Learn what is being done to decrease the number of people suffering from this parasite at the video below. Click image to the left or use the URL below. URL: "
Drier climates generally have less water for people to use.,(A) true (B) false,A,"Water shortages are common in much of the world. People are most likely to run short of water during droughts. A drought is a period of unusually low rainfall. Human actions have increased how often droughts occur. One way people can help to bring on drought is by cutting down trees. Trees add a lot of water vapor to the air. With fewer trees, the air is drier and droughts are more common. We already use six times as much water today as we did a hundred years ago. As the number of people rises, our need for water will grow. By the year 2025, only half the worlds people will have enough clean water. Water is such a vital resource that serious water shortages may cause other problems. Crops and livestock may die, so people will have less food available. Other uses of water, such as industry, may have to stop. This reduces the jobs people can get and the products they can buy. People and nations may fight over water resources. In extreme cases, people may die from lack of water. The Figure 21.7 shows the global water situation in the 2030s with water stress and water scarcity on the map. "
"Because of conservation, we use less water today than we did a century ago.",(A) true (B) false,B,"Conserving water means using less of it. Of course, this mostly applies to people in the wealthy nations that have the most water and also waste the most. "
Water is safe to drink as long as it is moving water.,(A) true (B) false,B,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
worlds most serious resource problem,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,E,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
period of unusually low rainfall,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,D,"Droughts occur when a region experiences unusually low precipitation for months or years (Figure 1.2). Periods of drought may create or worsen water shortages. Human activities can contribute to the frequency and duration of droughts. For example, deforestation keeps trees from returning water to the atmosphere by transpiration; part of the water cycle becomes broken. Because it is difficult to predict when droughts will happen, it is difficult for countries to predict how serious water shortages will be each year. Extended periods with lower than normal rainfall cause droughts. "
degree to which water is polluted,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,F,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
any method of providing extra water to plants,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,B,"A much more efficient way to water crops is drip irrigation (Figure 1.2). With drip irrigation, pipes and tubes deliver small amounts of water directly to the soil at the roots of each plant or tree. The water is not sprayed into the air or over the ground, so nearly all of it goes directly into the soil and plant roots. "
underground pipe that collects runoff water,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,C,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
greatest use of water worldwide,(A) agriculture (B) irrigation (C) storm sewer (D) drought (E) water scarcity (F) water quality,A,"Figure 21.1 shows how people use water worldwide. The greatest use is for agriculture and then industry. Municipal use is last, but is also important. Municipal use refers to water used by homes and businesses in communities. "
The Gulf of Mexico oil spill began with,(A) a ship running aground (B) a rig that cracked apart in a storm (C) a rig explosion (D) an onshore pipeline breaking apart,C,"Two days after the explosion, the drill rig sank. The 5,000-foot pipe that connected the wellhead to the drilling platform bent. Oil was free to gush into the Gulf of Mexico from nearly a mile deep (Figure 1.2). Initial efforts to cap or contain the spill at or near its source all failed to stop the vast oil spill. It was not until July 15, nearly three months after the accident, that the well was successfully capped. Estimating the flow of oil into the Gulf from the well was extremely difficult because the leak was so far below the surface. The U.S. government estimates that about 4.9 million barrels entered the Gulf at a rate of 35,000 to 60,000 barrels a day. The largest previous oil spill in the United States was of 300,000 barrels by the Exxon Valdez in 1989 in Prince William Sound, Alaska. "
Industrial pollutants include,(A) radioactive substances (B) chemicals (C) heat (D) all of these,D,"Factories and hospitals spew pollutants into the air and waterways (Figure 1.2). Some of the most hazardous industrial pollutants include: Radioactive substances from nuclear power plants and medical and scientific sources. Heavy metals, organic toxins, oils, and solids in industrial waste. Chemicals, such as sulfur, from burning fossil fuels. Oil and other petroleum products from supertanker spills and offshore drilling accidents. Heated water from industrial processes, such as power stations. "
Dead zones are found mostly,(A) off of industrialized areas in developed nations (B) in the Gulf of Mexico (C) off of farming areas in developing nations (D) none of these,C,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
The temperature of a lake may rise if the water is,(A) released from a reservoir (B) used to cool a power plant (C) exposed to oil drilling (D) all of these,B,"If heated water is released into a body of water, it may cause thermal pollution. Thermal pollution is a reduction in the quality of water because of an increase in water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and factories. This water is heated and then returned to the natural environment at a higher temperature. Warm water cant hold as much dissolved oxygen as cool water, so an increase in the temperature of water decreases the amount of oxygen it contains. Fish and other organisms adapted to a particular temperature range and oxygen concentration may be killed by the change in water temperature. "
An example of point source pollution is,(A) a nuclear power plant (B) acid rain (C) a set of enormous animal farms (D) steel factories along a river,A,"An example of point-source pollution is the release of pollution into a body of water through a pipe from a factory or sewage treatment plant. Waste water from a factory might contain dangerous chemicals such as strong acids, mercury, or lead. Water from a sewage treatment plant might contain untreated or partially treated sewage. Such pollution can make water dangerous for drinking or other uses. You can learn more about the problem of sewage contaminating the water in U.S. coastal communities by watching this video:  MEDIA Click image to the left or use the URL below. URL:  In poor nations, many people have no choice but to drink water from polluted sources. Drinking sewage-contaminated water causes waterborne diseases, due to pathogens such as protozoa, viruses, or bacteria. Most waterborne diseases cause diarrhea. "
Point source pollution is harder to control.,(A) true (B) false,B,"Pollution that enters water at just one point is called point source pollution. For example, chemicals from a factory might empty into a stream through a pipe or set of pipes (see Figure 21.9). Pollution that enters in many places is called non-point source pollution. This means that the pollution is from multiple sources. With non-point source pollution, runoff may carry the pollution into a body of water. Which type of pollution do you think is harder to control? "
Agricultural pollution can contaminate well water.,(A) true (B) false,A,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
Livestock waste is always stored safely in lagoons.,(A) true (B) false,B,"Runoff from crops, livestock, and poultry farming carries contaminants such as fertilizers, pesticides, and animal waste into nearby waterways (Figure 1.3). Soil and silt also run off farms. Animal wastes may carry harmful diseases, particularly in the developing world. The high density of animals in a factory farm means that runoff from the area is full of pollutants. Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. "
Industrial water pollution commonly includes toxic chemicals such as mercury.,(A) true (B) false,A,"Factories and power plants may pollute water with harmful substances. Many industries produce toxic chemicals. Some of the worst are arsenic, lead, and mercury. Nuclear power plants produce radioactive chemicals. They cause cancer and other serious health problems. Oil tanks and pipelines can leak. Leaks may not be noticed until a lot of oil has soaked into the ground. The oil may pollute groundwater so it is no longer fit to drink. "
No harm is done if lawn chemicals are washed into storm sewers.,(A) true (B) false,B,"What can individuals do to protect water quality? Find approved recycling or disposal facilities for motor oil and household chemicals. Use lawn, garden, and farm chemicals sparingly and wisely. Repair automobile or boat engine leaks immediately. Keep litter, pet waste, leaves, and grass clippings out of street gutters and storm drains. Click image to the left or use the URL below. URL: "
Water pollution contributes to water shortages.,(A) true (B) false,A,"Water pollution contributes to water shortages by making some water sources unavailable for use. In underdeveloped countries, raw sewage is dumped into the same water that people drink and bathe in. Even in developed countries, water pollution affects human and environmental health. Water pollution includes any contaminant that gets into lakes, streams, and oceans. The most widespread source of water contamination in developing countries is raw sewage. In developed countries, the three main sources of water pollution are described below. "
Most ocean pollution comes from ships at sea.,(A) true (B) false,B,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
Most of the pollution in the oceans is carried there by rivers and runoff.,(A) true (B) false,A,"The oceans are most polluted along coasts. Why do you think thats the case? Of course, its because most pollution enters the oceans from the land. Runoff and rivers carry the majority of pollution into the ocean. Many cities dump their wastewater directly into coastal waters. In some parts of the world, raw sewage and trash may be thrown into the water (see Figure 21.12). Coastal water may become so polluted that people get sick if they swim in it or eat seafood from it. The polluted water may also kill fish and other ocean life. "
Animal waste and fertilizers bring nutrients to nearby water sources.,(A) true (B) false,A,"Runoff from crops, livestock, and poultry farming carries contaminants such as fertilizers, pesticides, and animal waste into nearby waterways (Figure 1.3). Soil and silt also run off farms. Animal wastes may carry harmful diseases, particularly in the developing world. The high density of animals in a factory farm means that runoff from the area is full of pollutants. Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. "
Oil leaks and spills occur only in the oceans.,(A) true (B) false,B,"Large oil spills, like the Exxon Valdez in Alaska in 1989, get a lot of attention, as they should. Besides these large spills, though, much more oil enters the oceans from small leaks that are only a problem locally. In this concept, well take a look at a large recent oil spill in the Gulf of Mexico. "
Thermal pollution kills fish by making the water too cold.,(A) true (B) false,B,"Thermal pollution is pollution that raises the temperature of water. This is caused by power plants and factories that use the water to cool their machines. The plants pump cold water from a lake or coastal area through giant cooling towers, like those in Figure 21.14. As it flows through the towers, the cold water absorbs heat. This warmed water is returned to the lake or sea. Thermal pollution can kill fish and other water life. Its not just the warm temperature that kills them. Warm water cant hold as much oxygen as cool water. If the water gets too warm, there may not be enough oxygen for living things. "
"Water pollution includes any contaminant that gets into lakes, streams, and oceans.",(A) true (B) false,A,"Water pollution contributes to water shortages by making some water sources unavailable for use. In underdeveloped countries, raw sewage is dumped into the same water that people drink and bathe in. Even in developed countries, water pollution affects human and environmental health. Water pollution includes any contaminant that gets into lakes, streams, and oceans. The most widespread source of water contamination in developing countries is raw sewage. In developed countries, the three main sources of water pollution are described below. "
Factory farms with thousands of animals pollute ocean water with animal wastes.,(A) true (B) false,A,"Runoff from crops, livestock, and poultry farming carries contaminants such as fertilizers, pesticides, and animal waste into nearby waterways (Figure 1.3). Soil and silt also run off farms. Animal wastes may carry harmful diseases, particularly in the developing world. The high density of animals in a factory farm means that runoff from the area is full of pollutants. Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. "
"In some places, people dump trash and raw sewage into the ocean.",(A) true (B) false,A,"Trash from land may end up as trash in the ocean, sometimes extremely far from land. Some of it will eventually wash ashore, possibly far from where it originated (Figure 1.1). "
"If polluted water infiltrates the ground, it is no longer a problem.",(A) true (B) false,B,"Groundwater is a bit safer from pollution than surface water from some types of pollution because some pollutants are filtered out by the rock and soil that water travels through as it travels through the ground or once it is in the aquifer. But rock and soil cant get out everything, depending on the type of rock and soil and on the types of pollutants. As it is, about 25% of the usable groundwater and 45% of the municipal groundwater supplies in the United States are polluted. "
major cause of water pollution,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,D,"Water pollution has many causes. One of the biggest causes is fertilizer in runoff. Runoff dissolves fertilizer as it flows over farm fields, lawns, and golf courses. It carries the dissolved fertilizer into bodies of water. More dissolved fertilizer may enter a body of water at the mouth of a river, but there is generally no single point where this type of pollution enters the water. Thats why this type of water pollution is called nonpoint-source pollution. "
pollution that enters water in many places,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,A,"Unlike runoff, which enters bodies of water everywhere, some sources of pollution enter the water at a single point. This type of water pollution is called point-source pollution. "
pollution that raises the temperature of water,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,F,"Thermal pollution is pollution that raises the temperature of water. This is caused by power plants and factories that use the water to cool their machines. The plants pump cold water from a lake or coastal area through giant cooling towers, like those in Figure 21.14. As it flows through the towers, the cold water absorbs heat. This warmed water is returned to the lake or sea. Thermal pollution can kill fish and other water life. Its not just the warm temperature that kills them. Warm water cant hold as much oxygen as cool water. If the water gets too warm, there may not be enough oxygen for living things. "
where ocean pollution is worst,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,E,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
pollution that enters water in just one place,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,C,"Unlike runoff, which enters bodies of water everywhere, some sources of pollution enter the water at a single point. This type of water pollution is called point-source pollution. "
area in a body of water where nothing can live,(A) non-point source pollution (B) dead zone (C) point source pollution (D) agriculture (E) coast (F) thermal pollution,B,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
Sources of water pollution include,(A) industry (B) agriculture (C) municipal sources (D) all of the above,D,"There are three main sources of water pollution: 1. Agriculture. 2. Industry. 3. Municipal, or community, sources. "
Examples of non-point source pollution include,(A) a factory discharging chemicals into a lake through a pipe (B) runoff carrying pesticides into a lake from surrounding farmland (C) a nuclear power plant pumping warm water into a nearby lake (D) two of the above,B,"Pollution that enters water at just one point is called point source pollution. For example, chemicals from a factory might empty into a stream through a pipe or set of pipes (see Figure 21.9). Pollution that enters in many places is called non-point source pollution. This means that the pollution is from multiple sources. With non-point source pollution, runoff may carry the pollution into a body of water. Which type of pollution do you think is harder to control? "
"If dissolved fertilizer enters bodies of water, it can lead to",(A) too many fish (B) too many algae (C) dead zones (D) two of the above,D,"When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. You can see one in Figure 25.5. The algae out-compete other water organisms. They may make the water unfit for human consumption or recreation. "
Bacteria are most likely to contaminate water if it is polluted by a(n),(A) oil refinery (B) chemical plant (C) nuclear power plant (D) sewage treatment plant,D,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
Nuclear power plants use water for,(A) cooling (B) chemical reactions (C) nuclear fusion reactions (D) neutralizing radioactive elements,A,"Nuclear power plants use uranium that has been concentrated in fuel rods (Figure 5.6). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion. Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. "
Water pollution is a problem,(A) only in poor nations (B) mainly in rich nations (C) all over the world (D) only for ocean animals,C,Water pollution can be reduced in two ways: Keep the water from becoming polluted. Clean water that is already polluted. 
Passage of the Clean Water Act,(A) established the Environmental Protection Agency (B) outlawed emitting all pollutants into water (C) made governments responsible for all pollution (D) all of these,A,"In the U.S., concern over water pollution has resulted in many federal laws. Some of these laws go all the way back to the 1800s! The laws prohibit the disposal of any waste into the nations rivers, lakes, streams, and other bodies of water, unless a person first has a permit. Growing concern for controlling water pollutants led to the enactment of the Clean Water Act in 1972. The Clean Water Act set water quality standards. It also limits the pollution that can enter the waterways. Other countries are also actively preventing water pollution and purifying water ( Figure 1.1). A water purification station in France. Contaminants are removed to make clean water. "
A burning river helped people realize the need to protect water.,(A) true (B) false,A,"Disasters such as rivers burning led to new U.S. laws to protect the water. For example, the Environmental Protection Agency (EPA) was established, and the Clean Water Act was passed. Now, water is routinely tested. Pollution is tracked to its source, and polluters are forced to fix the problem and clean up the pollution. They are also fined. These consequences have led industries, agriculture, and communities to pollute the water much less than before. "
Water pollution has been reduced by laws fining polluters.,(A) true (B) false,A,"Disasters such as rivers burning led to new U.S. laws to protect the water. For example, the Environmental Protection Agency (EPA) was established, and the Clean Water Act was passed. Now, water is routinely tested. Pollution is tracked to its source, and polluters are forced to fix the problem and clean up the pollution. They are also fined. These consequences have led industries, agriculture, and communities to pollute the water much less than before. "
Contaminants in water that need to be treated include,(A) bacteria (B) algae (C) viruses (D) and fungi (E) b some elements (F) c chemical pollutants (G) d all of these,D,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
Most water pollution is caused by recreation on the water.,(A) true (B) false,B,"There are three main sources of water pollution: 1. Agriculture. 2. Industry. 3. Municipal, or community, sources. "
Water purification,(A) increases acidity (B) does not always produce water that is safe for drinking (C) removes all contaminants (D) none of these,B,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
What can governments and international agencies do to prevent pollution and clean up the oceans?,(A) pass laws (B) provide funding (C) enforce laws (D) all of the above,D,Water pollution can be reduced in two ways: Keep the water from becoming polluted. Clean water that is already polluted. 
Coagulation is used during water treatment to remove chemicals from water.,(A) true (B) false,B,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
Filters are used during water treatment to remove bacteria from water.,(A) true (B) false,B,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
To discard motor oil,(A) put it in the storm sewers (B) put it down the drain (C) take it to an approved disposal facility (D) put it on the ground,C,"What can individuals do to protect water quality? Find approved recycling or disposal facilities for motor oil and household chemicals. Use lawn, garden, and farm chemicals sparingly and wisely. Repair automobile or boat engine leaks immediately. Keep litter, pet waste, leaves, and grass clippings out of street gutters and storm drains. Click image to the left or use the URL below. URL: "
People in wealthy nations waste more water than people in poor nations.,(A) true (B) false,A,"Conserving water means using less of it. Of course, this mostly applies to people in the wealthy nations that have the most water and also waste the most. "
The single biggest use of water is for industry.,(A) true (B) false,B,"Figure 21.1 shows how people use water worldwide. The greatest use is for agriculture and then industry. Municipal use is last, but is also important. Municipal use refers to water used by homes and businesses in communities. "
Water-saving toilets use only about half as much water as regular toilets.,(A) true (B) false,A,"Its easy to save water at home. If you save even a few gallons a day you can make a big difference over the long run. The best place to start saving water is in the bathroom. Toilet flushing is the single biggest use of water in the home. Showers and baths are the next biggest use. Follow the tips below to save water at home. Install water-saving toilets. They use only about half as much water per flush. A single household can save up to 20,000 gallons a year with this change alone! Take shorter showers. You can get just as clean in 5 minutes as you can in 10. And youll save up to 50 gallons of water each time you shower. Thats thousands of gallons each year. Use low-flow shower heads. They use about half as much water as regular shower heads. They save thousands of gallons of water. Fix leaky shower heads and faucets. All those drips really add up. At one drip per second, more than 6,000 gallons go down the drain in a year per faucet! Dont leave the water running while you brush your teeth. You could save as much as 10 gallons each time you brush. That could add up to 10,000 gallons in a year. Landscape your home with plants that need little water. This could result in a huge savings in water use. Look at the garden in Figure 21.20. It shows that you dont have to sacrifice beauty to save water. "
"When communities ration water, they ban its use by certain households.",(A) true (B) false,B,"Some communities save water with rationing. Much rationing takes place only during times of drought. During rationing, water may not be used for certain things. For example, communities may ban lawn watering and car washing. People may be fined if they use water in these ways. You can do your part. Follow any bans where you live. "
Chemicals are added to untreated water to cause solids to clump together.,(A) true (B) false,A,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
Cleaning the ocean of pollutants is difficult because the ocean is so vast.,(A) true (B) false,A,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
"To protect the water supply, you should dispose of motor oil by",(A) pouring it down the drain (B) spreading it over the ground (C) letting it run into a storm sewer (D) none of the above,D,"What can individuals do to protect water quality? Find approved recycling or disposal facilities for motor oil and household chemicals. Use lawn, garden, and farm chemicals sparingly and wisely. Repair automobile or boat engine leaks immediately. Keep litter, pet waste, leaves, and grass clippings out of street gutters and storm drains. Click image to the left or use the URL below. URL: "
It is easier to clean water that has become polluted than to keep it from becoming polluted.,(A) true (B) false,B,Water pollution can be reduced in two ways: Keep the water from becoming polluted. Clean water that is already polluted. 
"If pet wastes pollute the water supply, they can",(A) add nitrogen to the water (B) cause overgrowth of algae (C) pollute the water with bacteria (D) all of the above,D,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
"Water for drinking, medicine, agriculture, and water parks is all purified to the same quality.",(A) true (B) false,B,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
The goal of all water treatment is to,(A) make water pure enough to drink (B) remove unwanted substances from water (C) make water safe enough to return to the natural environment (D) all of the above,B,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
Which processes are involved in treating drinking water?,(A) coagulation (B) sedimentation (C) filtration (D) all of the above,D,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
Wastewater contains hundreds of contaminants.,(A) true (B) false,A,"Wastewater from cities and towns contains many different contaminants from many different homes, businesses, and industries (Figure 1.1). Contaminants come from: Sewage disposal (some sewage is inadequately treated or untreated). Storm drains. Septic tanks (sewage from homes). Boats that dump sewage. Yard runoff (fertilizer and herbicide waste). Large numbers of sewage spills into San Francisco Bay are forcing cities, water agencies and the public to take a closer look at wastewater and its impacts on the health of the bay. QUEST investigates the causes of the spills and whats being done to prevent them. Click image to the left or use the URL below. URL: "
"In a wastewater treatment plant, water is treated in one single process.",(A) true (B) false,B,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
Ways that people can conserve water include all of the following except,(A) fixing leaky faucets (B) taking shorter showers (C) using low-flow shower heads (D) leaving on the water while brushing teeth,D,"Conserving water means using less of it. Of course, this mostly applies to people in the wealthy nations that have the most water and also waste the most. "
The single biggest use of water in the home is,(A) toilet flushing (B) cooking (C) cleaning (D) laundry,A,"Figure 21.1 shows how people use water worldwide. The greatest use is for agriculture and then industry. Municipal use is last, but is also important. Municipal use refers to water used by homes and businesses in communities. "
process in water treatment in which small particles are separated from water,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,E,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
process in water treatment in which large particles settle to the bottom of the water,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,D,"The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. "
series of processes to improve the quality of water,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,A,"Keeping water from becoming polluted often requires laws to be sure that people and companies behave responsibly. In the United States, the Clean Water Act gives the Environmental Protection Agency (EPA) the authority to set standards for water quality for industry, agriculture, and domestic uses. The law gives the EPA the authority to reduce the discharge of pollution into waterways, finance wastewater treatment plants, and manage runoff. Since its passage in 1972, more wastewater treatment plants have been constructed and the release of industrial waste into the water supply is better controlled. Scientists control water pollution by sam- pling the water and studying the pollutants that are in the water. The United Nations and other international groups are working to improve global water quality standards by pro- viding the technology for treating water. These organizations also educate people in how to protect and improve the quality of the water they use (Figure 1.1). Click image to the left or use the URL below. URL: "
process in water treatment in which chlorine is added to water,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,G,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
preserving a resource by using less of it,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,C,"Reducing resource use means just what it says using fewer resources. There are lots of ways to reduce our use of resources. Buy durable goods. Choose items that are well made so they will last longer. Youll buy fewer items in the long run, so youll save money as well as resources. Thats a win-win! Repair rather than replace. Fix your bike rather than buying a new one. Sew on a button instead of buying a new shirt. Youll use fewer resources and save money. Buy only what you need. Dont buy a gallon of milk if you can only drink half of it before it spoils. Instead, buy a half gallon and drink all of it. You wont be wasting resources (or money!). Buy local. For example, buy local produce at a farmers market, like the one in Figure 20.5. A lot of resources are saved by not shipping goods long distances. Products bought at farmers markets use less packaging, too! About a third of what we throw out is packaging. Try to buy items with the least amount of packaging. For example, buy bulk items instead of those that are individually wrapped. Also, try to select items with packaging that can be reused or recycled. This is called precycling. Pop cans and plastic water bottles, for example, are fairly easy to recycle. Some types of packaging are harder to recycle. You can see examples in Figure 20.6. If it cant be reused or recycled, its a waste of resources. Many plastics: The recycling symbol on the bottom of plastic containers shows the type of plastic they contain. Numbers 1 and 2 are easier to recycle than higher numbers. Mixed materials: Packaging that contains more than one material may be hard to recycle. This carton is made mostly of cardboard. But it has plastic around the opening. "
"contamination with chemicals, waste, or other harmful substances",(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,B,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
process in water treatment in which solids in water clump together,(A) water treatment (B) pollution (C) conservation (D) sedimentation (E) filtration (F) coagulation (G) disinfection,F,"Water treatment is a series of processes that remove unwanted substances from water. The goal of water treatment is to make the water safe to return to the natural environment or to the human water supply. Treating water for other purposes may not include all the same steps. Thats because water used in agriculture or industry may not have to be as clean as drinking water. You can see how water for drinking is treated in Figure 21.18. Treating drinking water requires at least four processes: 1. Chemicals are added to untreated water. They cause solids in the water to clump together. This is called coagulation. 2. The water is moved to tanks. The clumped solids sink to the bottom of the water. This is called sedimentation. 3. The water is passed through filters that remove smaller particles from the water. This is called filtration. 4. Chlorine is added to the water to kill bacteria and other microbes. This is called disinfection. Finally, the water is pure enough to drink. "
type of pollutant that forms when other pollutants undergo chemical reactions,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,G,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
Many of the smoggiest cities are in which state?,(A) California (B) New York (C) Texas (D) Florida,A,"Air quality in a region is not just affected by the amount of pollutants released into the atmosphere in that location but by other geographical and atmospheric factors. Winds can move pollutants into or out of a region and a mountain range can trap pollutants on its leeward side. Inversions commonly trap pollutants within a cool air mass. If the inversion lasts long enough, pollution can reach dangerous levels. Pollutants remain over a region until they are transported out of the area by wind, diluted by air blown in from another region, transformed into other compounds, or carried to the ground when mixed with rain or snow. Table 1.1 lists the smoggiest cities in 2013: 7 of the 10 are in California. Why do you think California cities are among those with the worst air pollution? The state has the right conditions for collecting pollutants including mountain ranges that trap smoggy air, arid and sometimes windless conditions, agriculture, industry, and lots and lots of cars. Rank 1 2 3 4 5 6 7 8 9 10 City, State Los Angeles area, California Visalia-Porterville, California Bakersfield-Delano, California Fresno-Madera, California Hanford-Corcoran, California Sacramento area, California Houston area, Texas Dallas-Fort Worth, Texas Washington D.C. area El Centro, California "
primary pollutant that is a carbon compound such as methane,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,D,Natural gas is mostly methane. 
Slash-and-burn is done primarily,(A) for energy (B) to clear land for agriculture (C) to clear land for construction (D) none of these,B,"Other habitats that are being rapidly destroyed are forests, especially tropical rainforests. The largest cause of deforestation today is slash-and-burn agriculture (shown in the opening image). This means that when people want to turn a forest into a farm, they cut down all of the trees and then burn the remainder of the forest. This technique is used by over 200 million people in tropical forests throughout the world. As a consequence of slash-and-burn agriculture, nutrients are quickly lost from the soil. This often results in people abandoning the land within a few years. Then the top soil erodes and desertification can follow. Desertification Herds of bison also made up part of the tallgrass prairie community. turns forest into a desert, where it is difficult for plants to grow. Half of the Earths mature tropical forests are gone. At current rates of deforestation, all tropical forests will be gone by the year 2090. "
type of pollutant that enters the air directly,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,C,"The two types of air pollutants are primary pollutants, which enter the atmosphere directly, and secondary pollutants, which form from a chemical reaction. "
How many pollutants does the Clean Air Act of 1970 regulate?,(A) 6 (B) 89 (C) 189 (D) 289,C,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
Pollutants may collect,(A) beside mountain ranges (B) in inversions (C) when there is little wind (D) all of these,D,"Pollutants include materials that are naturally occurring but are added to the atmosphere so that they are there in larger quantities than normal. Pollutants may also be human-made compounds that have never before been found in the atmosphere. Pollutants dirty the air, change natural processes in the atmosphere, and harm living things. "
solid particle in the air,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,E,"Air includes many tiny particles. The particles may consist of dust, soil, salt, smoke, or ash. Some particles pollute the air and may make it unhealthy to breathe. But having particles in the air is very important. Tiny particles are needed for water vapor to condense on. Without particles, water vapor could not condense. Then clouds could not form and Earth would have no rain. "
measure of the pollutants in air,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,A,"Air quality is a measure of the pollutants in the air. More pollutants mean poorer air quality. Air quality, in turn, depends on many factors. Some natural processes add pollutants to the air. For example, forest fires and volcanoes add carbon dioxide and soot. In dry areas, the air often contains dust. However, human actions cause the most air pollution. The single biggest cause is fossil fuel burning. "
Smog that forms from a reaction with sunlight is known as,(A) photographic smog (B) photochemical smog (C) photosynthesized smog (D) photogenic smog,B,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
brown haze that forms in air when certain pollutants react together in sunlight,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,B,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
primary component of photochemical smog,(A) air quality (B) photochemical smog (C) primary pollutant (D) VOC (E) particulate (F) ozone (G) secondary pollutant,F,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
Before the Industrial Revolution there was very little air pollution that wasnt natural.,(A) true (B) false,A,Air pollution started to be a problem when early people burned wood for heat and cooking fires in enclosed spaces such as caves and small tents or houses. But the problems became more widespread as fossil fuels such as coal began to be burned during the Industrial Revolution (Figure 1.1). The 2012 Olympic Games in London opening ceremony contained a reen- actment of the Industrial Revolution - complete with pollution streaming from smokestacks. 
Burning fossil fuels releases carbon dioxide into the atmosphere.,(A) true (B) false,A,"Human actions are influencing the carbon cycle. Burning of fossil fuels releases the carbon dioxide that was stored in ancient plants. Carbon dioxide is a greenhouse gas and is a cause of global warming. Forests are also being destroyed. Trees may be cut down for their wood, or they may be burned to clear the land for farming. Burning wood releases more carbon dioxide into the atmosphere. You can see how a tropical rainforest was cleared for farming in Figure 18.12. With forests shrinking, there are fewer trees to remove carbon dioxide from the air. This makes the greenhouse effect even worse. "
About 150 million tons of pollutants enter into the atmosphere every year.,(A) true (B) false,A,Most pollutants enter the air when fossil fuels burn. Some are released when forests burn. Others evaporate into the air. 
The Clean Air Act regulates carbon dioxide.,(A) true (B) false,B,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
Ozone in the lower atmosphere protects life from UV radiation.,(A) true (B) false,B,"Ozone is a molecule composed of three oxygen atoms, (O3 ). Ozone in the upper atmosphere absorbs high-energy ultraviolet (UV) radiation coming from the Sun. This protects living things on Earths surface from the Suns most harmful rays. Without ozone for protection, only the simplest life forms would be able to live on Earth. The highest concentration of ozone is in the ozone layer in the lower stratosphere. "
The worst air pollution in the U.S. occurs in,(A) New York State (B) New Jersey (C) California (D) Florida,C,"At the same time, many U.S. cities had air pollution problems. Some of the worst were in California. Cars were becoming more popular. Oil refineries and power plants also polluted the air. Mountain ranges trapped polluted air over cities. The California sunshine caused chemical reactions among the pollutants. These reactions produced many more harmful compounds. "
The Big Smoke was an incident of deadly air pollution that occurred in the mid-1900s in,(A) Los Angeles (B) San Francisco (C) Mexico City (D) London,D,"By the mid-1900s, air quality in many big cities was very bad. The worst incident came in December 1952. A temperature inversion over London, England, kept cold air and pollutants near the ground. The air became so polluted that thousands of people died in just a few days. This event was called the Big Smoke. "
"In the U.S. today, air pollution comes from",(A) vehicles (B) factories (C) power plants (D) all of the above,D,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
Most primary pollutants are released by,(A) volcanic eruptions (B) natural processes (C) human activities (D) forest fires,C,"Some primary pollutants are natural, such as volcanic ash. Dust is natural but exacerbated by human activities; for example, when the ground is torn up for agriculture or development. Most primary pollutants are the result of human activities, the direct emissions from vehicles and smokestacks. Primary pollutants include: Carbon oxides include carbon monoxide (CO) and carbon dioxide (CO2 ) (Figure 1.1). Both are colorless, odorless gases. CO is toxic to both plants and animals. CO and CO2 are both greenhouse gases. Nitrogen oxides are produced when nitrogen and oxygen from the atmosphere come together at high temper- atures. This occurs in hot exhaust gas from vehicles, power plants, or factories. Nitrogen oxide (NO) and nitrogen dioxide (NO2 ) are greenhouse gases. Nitrogen oxides contribute to acid rain. Sulfur oxides include sulfur dioxide (SO2 ) and sulfur trioxide (SO3 ). These form when sulfur from burning coal reaches the air. Sulfur oxides are components of acid rain. Particulates are solid particles, such as ash, dust, and fecal matter (Figure 1.2). They are commonly formed from combustion of fossil fuels, and can produce smog. Particulates can contribute to asthma, heart disease, and some types of cancers. Lead was once widely used in automobile fuels, paint, and pipes. This heavy metal can cause brain damage or blood poisoning. High CO2 levels are found in major metropolitan areas and along the major interstate highways. Particulates from a brush fire give the sky a strange glow in Arizona. "
Pollutants released into the air when fossil fuels burn include,(A) carbon monoxide (B) carbon dioxide (C) particulates (D) all of the above,D,"Burning fossil fuels releases many pollutants into the air. These pollutants include carbon monoxide, carbon dioxide, nitrogen dioxide, and sulfur dioxide. Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum. Power plants and factories account for more than a quarter of fossil fuel use. Power plants burn fossil fuels to generate electricity. Factories burn fossil fuels to power machines. Homes and other buildings also burn fossil fuels. The energy they release is used for heating, cooking, and other purposes. "
Smog consists mainly of,(A) smoke (B) particulates (C) water vapor (D) none of the above,D,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
Almost half of the fossil fuels that are burned are used by,(A) factories (B) power plants (C) cars and trucks (D) homes and other buildings,C,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
Air pollution is caused completely by human actions.,(A) true (B) false,B,Human health suffers in locations with high levels of air pollution. 
The air in the U.S. is more polluted now than it was 50 years ago.,(A) true (B) false,B,"By 1970, it was clear that something needed to be done to protect air quality. In the U.S., the Clean Air Act was passed. It limits what can be released into the air. As a result, the air in the U.S. is much cleaner now than it was 50 years ago. But air pollution has not gone away. Vehicles, factories, and power plants still release more than 150 million tons of pollutants into the air each year. "
Livestock wastes pollute the air with methane.,(A) true (B) false,A,"VOCs enter the air by evaporation. VOCs are found in many products, like paints and petroleum products. Methane is a VOC that evaporates from livestock waste and landfills. "
Animal wastes add particulates to the atmosphere.,(A) true (B) false,A,Particulates cause lung diseases. They can also increase the risk of heart disease and the number of asthma attacks. Particulates block sunlight from reaching Earths surface. This means there is less energy for photosynthesis. Less photosynthesis means that plants and phytoplankton produce less food. This affects whole ecosystems. 
Particulates include only particles big enough to be seen by the unaided eye.,(A) true (B) false,B,"Particulates reduce visibility. In the western United States, people can now ordinarily see only about 100 to 150 kilometers (60 to 90 miles), which is one-half to two-thirds the natural (pre-pollution) range on a clear day. In the East, people can only see about 40 to 60 kilometers (25-35 miles), about one-fifth the distance they could see without any air pollution (Figure 1.1). Particulates reduce the amount of sunshine that reaches the ground, which may reduce photosynthesis. Since particulates form the nucleus for raindrops, snowflakes, or other forms of precipitation, precipitation may increase Smog in New York City. when particulates are high. An increase in particles in the air seems to increase the number of raindrops, but often decreases their size. By reducing sunshine, particulates can also alter air temperature as mentioned above. Imagine how much all of the sources of particulates combine to reduce temperatures. What affect might this have on global warming? "
Ozone forms when certain air pollutants are heated by direct sunlight.,(A) true (B) false,A,"Secondary pollutants form when primary pollutants undergo chemical reactions after they are released. Many occur as part of photochemical smog. This type of smog is seen as a brown haze in the air. Photochemical smog forms when certain pollutants react together in the presence of sunlight. You can see smog hanging in the air over San Francisco in Figure 22.2. Photochemical smog consists mainly of ozone (O3 ). The ozone in smog is the same compound as the ozone in the ozone layer,(O3 ). But ozone in smog is found near the ground. Figure 22.3 shows how it forms. When nitrogen oxides and VOCs are heated by the Sun, they lose oxygen atoms. The oxygen atoms combine with molecules of oxygen to form ozone. Smog ozone is harmful to humans and other living things. "
Paints and petroleum products release volatile organic compounds.,(A) true (B) false,A,"VOCs enter the air by evaporation. VOCs are found in many products, like paints and petroleum products. Methane is a VOC that evaporates from livestock waste and landfills. "
Air pollution contributes to global warming.,(A) true (B) false,A,"Pollutants also affect the atmosphere through their contribution to global warming. Global warming is an increase in the Earths temperature. It is thought to be caused mostly by the increase of greenhouse gases like carbon dioxide. Greenhouse gases can be released by factories that burn fossil fuels. Over the past 20 years, burning fossil fuels has produced about three-quarters of the carbon dioxide from human activity. The rest of the carbon dioxide in the atmosphere is there because of deforestation, or cutting down trees ( Figure 1.4). Trees absorb carbon dioxide during cellular respiration, so when trees are cut down, they cannot remove carbon dioxide from the air. This increase in global temperature will cause the sea level to rise. It is also expected to produce an increase in extreme weather events and change the amount of precipitation. Global warming may also cause food shortages and species extinction. "
"In California, mountain ranges can trap polluted air over cities.",(A) true (B) false,A,"At the same time, many U.S. cities had air pollution problems. Some of the worst were in California. Cars were becoming more popular. Oil refineries and power plants also polluted the air. Mountain ranges trapped polluted air over cities. The California sunshine caused chemical reactions among the pollutants. These reactions produced many more harmful compounds. "
All primary pollutants come from directly from motor vehicles and smokestacks.,(A) true (B) false,B,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
type of pollutant that is usually higher in indoor than outdoor air,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,E,"You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. "
Particulates,(A) increase asthma attacks (B) significantly reduce rates of skin cancer (C) are responsible for neurological diseases (D) have no effect on human health,A,Particulates cause lung diseases. They can also increase the risk of heart disease and the number of asthma attacks. Particulates block sunlight from reaching Earths surface. This means there is less energy for photosynthesis. Less photosynthesis means that plants and phytoplankton produce less food. This affects whole ecosystems. 
buildup of heavy metals in the tissues of organisms,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,B,"Heavy metals, such as mercury and lead, are toxic to living things. They can enter food chains from the atmosphere. The metals build up in the tissues of organisms by bioaccumulation. Bioaccumulation is illustrated in Figure 22.8. As heavy metals are passed up a food chain they accumulate. Imagine a low-level consumer eating a producer. That consumer takes in all of the heavy metals from all of the producers that it eats. Then a higher-level consumer eats it and accumulates all the heavy metals from all of the lower-level consumers that it eats. In this way, heavy metals may accumulate. At high levels in the food chain, the heavy metals may be quite become quite concentrated. The higher up a food chain that humans eat, the greater the levels of toxic metals they take in. Thats why people should avoid eating too much of large fish such as tuna. Tuna are predators near the top of their food chains. They have been shown to contain high levels of mercury. In people, heavy metals can damage the brain and other organs. Unborn babies and young children are most affected. Thats because their organs are still developing. "
"Ozone is a pollutant in the __________, but is beneficial in the __________.",(A) stratosphere; thermosphere (B) thermosphere; troposphere (C) ionosphere; thermosphere (D) troposphere; stratosphere,D,"At this point you might be asking yourself, Is ozone bad or is ozone good? There is no simple answer to that question: It depends on where the ozone is located (Figure 1.1). In the troposphere, ozone is a pollutant. In the ozone layer in the stratosphere, ozone screens out high energy ultraviolet radiation and makes Earth habitable. "
harmful radiation blocked by the ozone layer,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,G,Ozone near the ground harms human health. But the ozone layer in the stratosphere protects us from solar rays. Thats why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. 
Limestone buildings and sculptures are eroded primarily by which of the following?,(A) UV radiation (B) acid rain (C) ozone pollution (D) CFCs,B,"Human activities are responsible for enormous amounts of mechanical weathering, by digging or blasting into rock to build homes, roads, and subways, or to quarry stone. (a) Humans are tremendous agents of mechanical weathering. (b) Salt weathering of building stone on the island of Gozo, Malta. "
The phenomenon of pollutants adding up in an organism for life is known as,(A) bioaccumulation (B) accumulation (C) bio addition (D) biopollutants,A,All air pollutants cause some damage to living creatures and the environment. Different types of pollutants cause different types of harm. 
gas in smog that is harmful to plants and people,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,A,"The ozone in smog may damage plants. The effects of ozone add up over time. Plants such as trees, which normally live a long time, are most affected. Entire forests may die out if ozone levels are very high. Other plants, including crop plants, may also be damaged by ozone. You can see evidence of ozone damage in Figure 22.5. The ozone in smog is also harmful to human health. Figure 22.6 shows the levels of ozone to watch out for. Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems. "
type of air pollutant that destroys the ozone layer,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,F,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
Which fish species would typically contain the most mercury?,(A) krill (B) shark (C) trout (D) oyster,B,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
type of air pollutant that blocks sunlight from reaching Earths surface,(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,C,"The two types of air pollutants are primary pollutants, which enter the atmosphere directly, and secondary pollutants, which form from a chemical reaction. "
"odorless, colorless gas that is deadly to people in a confined space",(A) ozone (B) bioaccumulation (C) particulate (D) carbon monoxide (E) VOC (F) CFC (G) UV,D,"Carbon monoxide (CO) is toxic to both plants and animals. CO is deadly to people in a confined space, such as a closed home. Carbon monoxide is odorless and colorless, so people cant tell when they are breathing it. Thats why homes should have carbon monoxide detectors. You can see one in Figure 22.7. "
Lung cancer rates are increasing entirely due to more people smoking.,(A) true (B) false,B,"Lung cancer is a disease in which the cells found in the lungs grow out of control. The growing mass of cells can form a tumor that pushes into nearby tissues. The tumor will affect how these tissues work. Lung cancer is the most common cause of cancer-related death in men, and the second most common in women. It is responsible for 1.3 million deaths worldwide every year ( Figure 1.4). The most common symptoms are shortness of breath, coughing (including coughing up blood), and weight loss. The most common cause of lung cancer is exposure to tobacco smoke. The inside of a lung showing cancerous tissue. "
Ozone loss near the North and South Poles is about the same.,(A) true (B) false,B,"Ozone loss also occurs over the North Polar Region, but it is not enough for scientists to call it a hole. Why do you think there is less ozone loss over the North Pole area? The region of low ozone levels is small because the atmosphere is not as cold and PSCs do not form as readily. Still, springtime ozone levels are relatively low. This low moves south over some of the worlds most populated areas in Europe, North America, and Asia. At 40o N, the latitude of New York City, UV-B has increased about 4% per decade since 1978. At 55o N, the approximate latitude of Moscow and Copenhagen, the increase has been 6.8% per decade since 1978. Click image to the left or use the URL below. URL: "
"On a pH scale, numbers below 7 are basic.",(A) true (B) false,B,"The strength of acids and bases is measured on a scale called the pH scale (see Figure 10.10). The symbol pH represents acidity, or the concentration of hydrogen ions (H+ ) in a solution. Pure water, which is neutral, has a pH of 7. With a higher concentration of hydrogen ions, a solution is more acidic but has a lower pH. Therefore, acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. You can watch a video about the pH scale at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Particulates reduce the amount of sunshine that reaches the ground.,(A) true (B) false,A,"Particulates reduce visibility. In the western United States, people can now ordinarily see only about 100 to 150 kilometers (60 to 90 miles), which is one-half to two-thirds the natural (pre-pollution) range on a clear day. In the East, people can only see about 40 to 60 kilometers (25-35 miles), about one-fifth the distance they could see without any air pollution (Figure 1.1). Particulates reduce the amount of sunshine that reaches the ground, which may reduce photosynthesis. Since particulates form the nucleus for raindrops, snowflakes, or other forms of precipitation, precipitation may increase Smog in New York City. when particulates are high. An increase in particles in the air seems to increase the number of raindrops, but often decreases their size. By reducing sunshine, particulates can also alter air temperature as mentioned above. Imagine how much all of the sources of particulates combine to reduce temperatures. What affect might this have on global warming? "
Acid rain is produced by nitrogen and sulfur-oxides in the atmosphere.,(A) true (B) false,A,"Acid rain is caused by sulfur and nitrogen oxides emanating from power plants or metal refineries. The smokestacks have been built tall so that pollutants dont sit over cities (Figure 1.1). As they move, these pollutants combine with water vapor to form sulfuric and nitric acids. The acid droplets form acid fog, rain, snow, or they may be deposited dry. Most typical is acid rain (Figure 1.2). "
Breathing polluted air increases the risk of lung cancer.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
Ozone in smog can kill entire forests.,(A) true (B) false,A,"The ozone in smog may damage plants. The effects of ozone add up over time. Plants such as trees, which normally live a long time, are most affected. Entire forests may die out if ozone levels are very high. Other plants, including crop plants, may also be damaged by ozone. You can see evidence of ozone damage in Figure 22.5. The ozone in smog is also harmful to human health. Figure 22.6 shows the levels of ozone to watch out for. Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems. "
Some people are more sensitive to smog than others.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
Small fish are likely to contain higher levels of lead than large fish.,(A) true (B) false,B,"Heavy metals, such as mercury and lead, are toxic to living things. They can enter food chains from the atmosphere. The metals build up in the tissues of organisms by bioaccumulation. Bioaccumulation is illustrated in Figure 22.8. As heavy metals are passed up a food chain they accumulate. Imagine a low-level consumer eating a producer. That consumer takes in all of the heavy metals from all of the producers that it eats. Then a higher-level consumer eats it and accumulates all the heavy metals from all of the lower-level consumers that it eats. In this way, heavy metals may accumulate. At high levels in the food chain, the heavy metals may be quite become quite concentrated. The higher up a food chain that humans eat, the greater the levels of toxic metals they take in. Thats why people should avoid eating too much of large fish such as tuna. Tuna are predators near the top of their food chains. They have been shown to contain high levels of mercury. In people, heavy metals can damage the brain and other organs. Unborn babies and young children are most affected. Thats because their organs are still developing. "
Exposure to heavy metals can cause brain damage in unborn babies.,(A) true (B) false,A,"Methyl mercury poisoning can cause nervous system or brain damage, especially in infants and children. Children may experience brain damage or developmental delays. The phrase mad as a hatter was common when Lewis Carroll wrote his Alice in Wonderland stories. It was based on symptoms suffered by hatters who were exposed to mercury and experienced mercury poisoning while using the metal to make hats (Figure 1.3). Like mercury, other metals and VOCS can bioaccumulate, causing harm to animals and people high on the food chain. Mercury, a potent neurotoxin, has been flowing into the San Francisco Bay since the Gold Rush Era. It has settled in the bays mud and made its way up the food chain, endangering wildlife and making many fish unsafe to eat. Now a multi-billion-dollar plan aims to clean it up. Click image to the left or use the URL below. URL: "
Acid rain contains higher-than-normal levels of carbonic acid.,(A) true (B) false,B,"Acid rain is rain that has a pH less than 5 (see Figure 22.9). The pH of normal rain is 5.6. Its slightly acidic because carbon dioxide in the air dissolves in rain. This forms carbonic acid, a weak acid. "
Acid rain damages structures but does not harm living things.,(A) true (B) false,B,"Figure 22.11 shows some of the damage done by acid rain. Acid rain ends up in soil and bodies of water. This can make them very acidic. The acid strips soil of its nutrients. These changes can kill trees, fish, and other living things. Acid rain also dissolves limestone and marble. This can damage buildings, monuments, and statues. "
The hole in the ozone layer shows that air quality is improving.,(A) true (B) false,B,Ozone near the ground harms human health. But the ozone layer in the stratosphere protects us from solar rays. Thats why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. 
The ozone hole is bigger in some seasons than in others.,(A) true (B) false,A,"Most ozone loss it taking place over the South Pole and Antarctica. This is the location of the ozone hole. The ozone hole is also seasonal. The hole forms during the early part spring in the Southern Hemisphere and then grows northward. You can see the hole in Figure 22.13. Besides the ozone hole, the ozone layer is thinner over the Northern Hemisphere. "
Ground-level ozone is especially harmful to people with heart disease.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
Air pollutants that increase the risk of asthma include,(A) ozone (B) particulates (C) heavy metals (D) two of the above,D,"Many but not all cases of asthma can be linked to air pollution. During the 1996 Olympic Games, Atlanta, Georgia, closed off their downtown to private vehicles. This action decreased ozone levels by 28%. At the same time, there were 40% fewer hospital visits for asthma. Can scientists conclude without a shadow of a doubt that the reduction in ozone caused the reduction in hospital visits? What could they do to make that determination? Lung cancer among people who have never smoked is around 15% and is increasing. One study showed that the risk of being afflicted with lung cancer increases directly with a persons exposure to air pollution (Figure 1.1). The study concluded that no level of air pollution should be considered safe. Exposure to smog also increased the risk of dying from any cause, including heart disease. One study found that in the United States, children develop asthma at more than twice the rate of two decades ago and at four times the rate of children in Canada. Adults also suffer from air pollution-related illnesses that include lung disease, heart disease, lung cancer, and weakened immune systems. The asthma rate worldwide is rising 20% to 50% every decade. "
An air quality index of 120 parts of ozone per million parts of air is,(A) safe only for young people (B) unhealthy for some people (C) unhealthy for all people (D) safe for all people,B,Human health suffers in locations with high levels of air pollution. 
Nitrogen and sulfur oxides,(A) are toxic to humans (B) can cause lung diseases (C) form acid rain (D) all of the above,D,"Both nitrogen and sulfur oxides are toxic to humans. These compounds can cause lung diseases or make them worse. Nitrogen and sulfur oxides form acid rain, which is described below. "
Which organisms in a food chain have the highest levels of heavy metals?,(A) producers (B) primary consumers (C) secondary consumers (D) tertiary consumers,D,"Heavy metals, such as mercury and lead, are toxic to living things. They can enter food chains from the atmosphere. The metals build up in the tissues of organisms by bioaccumulation. Bioaccumulation is illustrated in Figure 22.8. As heavy metals are passed up a food chain they accumulate. Imagine a low-level consumer eating a producer. That consumer takes in all of the heavy metals from all of the producers that it eats. Then a higher-level consumer eats it and accumulates all the heavy metals from all of the lower-level consumers that it eats. In this way, heavy metals may accumulate. At high levels in the food chain, the heavy metals may be quite become quite concentrated. The higher up a food chain that humans eat, the greater the levels of toxic metals they take in. Thats why people should avoid eating too much of large fish such as tuna. Tuna are predators near the top of their food chains. They have been shown to contain high levels of mercury. In people, heavy metals can damage the brain and other organs. Unborn babies and young children are most affected. Thats because their organs are still developing. "
Sources of VOCs include,(A) cleaning solutions (B) building materials (C) paints (D) all of the above,D,"VOCs enter the air by evaporation. VOCs are found in many products, like paints and petroleum products. Methane is a VOC that evaporates from livestock waste and landfills. "
Normal rain is slightly acidic because it contains dissolved,(A) oxygen (B) nitrogen (C) carbon dioxide (D) nitrogen dioxide,C,"Acid rain is rain that has a pH less than 5 (see Figure 22.9). The pH of normal rain is 5.6. Its slightly acidic because carbon dioxide in the air dissolves in rain. This forms carbonic acid, a weak acid. "
The ozone layer in the atmosphere,(A) occurs in the stratosphere (B) is being destroyed by acid rain (C) protects Earth from harmful CFCs (D) forms only over the South Pole and Antarctica,A,Ozone near the ground harms human health. But the ozone layer in the stratosphere protects us from solar rays. Thats why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. 
Pollutants regulated by the Clean Air Act include,(A) CFCs (B) carbon dioxide (C) carbon monoxide (D) all of the above,C,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
A carbon tax,(A) encourages people to reduce carbon emissions (B) encourages conservation (C) charges money for carbon emissions (D) all of the above,D,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
Air pollutants that destroy ozone high in the atmosphere are regulated by the,(A) Clean Air Act (B) Kyoto Protocol (C) Montreal Protocol (D) none of the above,C,"Ozone is a molecule composed of three oxygen atoms, (O3 ). Ozone in the upper atmosphere absorbs high-energy ultraviolet (UV) radiation coming from the Sun. This protects living things on Earths surface from the Suns most harmful rays. Without ozone for protection, only the simplest life forms would be able to live on Earth. The highest concentration of ozone is in the ozone layer in the lower stratosphere. "
A car that runs on gasoline and electric power is,(A) a combustible engine vehicle (B) a hybrid vehicle (C) an electric vehicle (D) a diesel vehicle,B,"Gasoline is a concentrated resource. It contains a large amount of energy for its weight. This is important because the more something weighs, the more energy is needed to move it. If gasoline could only provide a little energy, a car would have to carry a lot of it to be able to travel very far. Or the car would need to be filled up frequently. So a highly concentrated energy resource is a practical fuel to power cars and other forms of transportation. Lets consider how gasoline powers a car. As gasoline burns, it releases most of its energy as heat. It also releases carbon dioxide gas and water vapor. The heat makes the gases expand. This forces the pistons inside the engine to move. The engine makes enough power to move the car. "
"In a cap-and-trade system, each nation is given a cap on emissions of",(A) CFCs (B) carbon dioxide (C) nitrogen oxides (D) all air pollutants,B,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
Catalytic converters,(A) break pollutants into non-toxic compounds (B) only work for particulates (C) reduce pollutants to zero (D) all of these,A,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
Removing carbon from the atmosphere is known as,(A) carbon sequestration (B) carbon stealing (C) unpolluting (D) carbon burying,A,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
Carbon taxes are meant to,(A) encourage people to use less fossil fuel (B) reduce carbon dioxide emissions (C) control greenhouse gases (D) all of the above,D,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
Ways of reducing air pollution include,(A) changing pollutants in exhaust to harmless gases (B) removing pollutants from exhaust before it is released (C) using fossil fuels more efficiently (D) all of the above,D,"There are two basic types of strategies for reducing pollution from fossil fuels: 1. Use less fossil fuel to begin with. 2. When fossil fuels must be used, prevent the pollution from entering the air. "
Nations benefit from developing emission reducing technologies in,(A) trade-and-spend (B) spend-and-reduce (C) cap-and-trade (D) cap-and-reduce,C,"The amount CO2 levels will rise in the next decades is unknown. What will this number depend on in the developed nations? What will it depend on in the developing nations? In the developed nations it will depend on technological advances or lifestyle changes that decrease emissions. In the developing nations, it will depend on how much their lifestyles improve and how these improvements are made. If nothing is done to decrease the rate of CO2 emissions, by 2030, CO2 emissions are projected to be 63% greater than they were in 2002. "
One purpose of catalytic converters is to,(A) reduce the use of fossil fuels (B) remove particulates from exhaust (C) break down pollutants to safe compounds (D) convert gas-burning cars to hybrid vehicles,C,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
Scrubbers are used in,(A) motor vehicles (B) power plants (C) factories (D) two of the above,D,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
"Since the passage of the Clean Air Act, emissions of the six major pollutants have decreased by 50%.",(A) true (B) false,A,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
Removing particles from emissions is a difficult process.,(A) true (B) false,A,"Pollutants are removed from the exhaust streams of power plants and industrial plants before they enter the atmo- sphere. Particulates can be filtered out, and sulfur and nitric oxides can be broken down by catalysts. Removing these oxides reduces the pollutants that cause acid rain. Particles are relatively easy to remove from emissions by using motion or electricity to separate particles from the gases. Scrubbers remove particles and waste gases from exhaust using liquids or neutralizing materials (Figure 1.3). Gases, such as nitrogen oxides, can be broken down at very high temperatures. A hydrogen fuel-cell car looks like a gasoline-powered car. Scrubbers remove particles and waste gases from exhaust. "
Destruction by ozone creates the ozone hole.,(A) true (B) false,B,"Ozone destruction creates the ozone hole where the layer is dangerously thin (Figure 1.3). As air circulates over Antarctica in the spring, the ozone hole expands northward over the southern continents, including Australia, New Zealand, southern South America, and southern Africa. UV levels may rise as much as 20% beneath the ozone hole. The hole was first measured in 1981 when it was 2 million square km (900,000 square miles). The 2006 hole was the largest ever observed at 28 million square km (11.4 million square miles). The size of the ozone hole each year depends on many factors, including whether conditions are right for the formation of PSCs. The September 2006 ozone hole, the largest observed (through 2013). Blue and purple colors show particularly low levels of ozone. "
Efforts to reduce greenhouse gas emissions have been successful.,(A) true (B) false,B,The Green Revolution has brought enormous impacts to the planet. 
"Without the Montreal Protocol, skin cancer cases in the U.S. would have been higher.",(A) true (B) false,A,"With less ozone in the stratosphere, more UV rays reach the ground. More UV rays increase skin cancer rates. Just a 1 percent loss of ozone causes a 5 percent increase in skin cancer. More UV rays also harm plants and phytoplankton. As a result, they produce less food. This may affect entire ecosystems. "
The Clean Air Act was passed in order to reduce global warming.,(A) true (B) false,B,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
"Because of the Clean Air Act, air pollution has been eliminated completely.",(A) true (B) false,B,"By 1970, it was clear that something needed to be done to protect air quality. In the U.S., the Clean Air Act was passed. It limits what can be released into the air. As a result, the air in the U.S. is much cleaner now than it was 50 years ago. But air pollution has not gone away. Vehicles, factories, and power plants still release more than 150 million tons of pollutants into the air each year. "
Pollution by ozone was reduced at least 50 percent by the Montreal Protocol.,(A) true (B) false,B,"The Montreal Protocol is a worldwide agreement on air pollution. It focuses on CFCs. It was signed by many countries in 1987. It controls almost 100 chemicals that can damage the ozone layer. Its aim is to return the ozone layer to its normal state. The Montreal Protocol has been effective in controlling CFCs. By 1995, few CFCs were still being used. But the ozone hole kept growing for several years after that because of the CFCs already in the atmosphere. It peaked in 2006. Since then, it has been somewhat smaller. "
Hydrogen cars produce about 10 percent of the air pollution of gas-burning cars.,(A) true (B) false,B,"Reducing air pollution from vehicles can be done in a number of ways. Breaking down pollutants before they are released into the atmosphere. Motor vehicles emit less pollution than they once did because of catalytic converters (Figure 1.1). Catalytic converters contain a catalyst that speeds up chemical reactions and breaks down nitrous oxides, carbon monoxide, and VOCs. Catalytic converters only work when they are hot, so a lot of exhaust escapes as the car is warming up. Catalytic converters are placed on mod- ern cars in the United States. Making a vehicle more fuel efficient. Lighter, more streamlined vehicles need less energy. Hybrid vehicles have an electric motor and a rechargeable battery. The energy that would be lost during braking is funneled into charging the battery, which then can power the car. The internal combustion engine only takes over when power in the battery has run out. Hybrids can reduce auto emissions by 90% or more, but many models do not maximize the possible fuel efficiency of the vehicle. A plug-in hybrid is plugged into an electricity source when it is not in use, perhaps in a garage, to make sure that the battery is charged. Plug-in hybrids run for a longer time on electricity and so are less polluting than regular hybrids. Plug-in hybrids began to become available in 2010. Developing new technologies that do not use fossil fuels. Fueling a car with something other than a liquid organic-based fuel is difficult. A fuel cell converts chemical energy into electrical energy. Hydrogen fuel cells harness the energy released when hydrogen and oxygen come together to create water (Figure 1.2). Fuel cells are extremely efficient and they produce no pollutants. But developing fuel-cell technology has had many problems and no one knows when or if they will become practical. "
Some scrubbers use steam to remove pollutants from exhaust.,(A) true (B) false,A,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
The Kyoto Protocol has been more successful than the Montreal Protocol.,(A) true (B) false,B,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
The size of the hole in the ozone layer has gotten somewhat smaller since 2006.,(A) true (B) false,A,"Ozone destruction creates the ozone hole where the layer is dangerously thin (Figure 1.3). As air circulates over Antarctica in the spring, the ozone hole expands northward over the southern continents, including Australia, New Zealand, southern South America, and southern Africa. UV levels may rise as much as 20% beneath the ozone hole. The hole was first measured in 1981 when it was 2 million square km (900,000 square miles). The 2006 hole was the largest ever observed at 28 million square km (11.4 million square miles). The size of the ozone hole each year depends on many factors, including whether conditions are right for the formation of PSCs. The September 2006 ozone hole, the largest observed (through 2013). Blue and purple colors show particularly low levels of ozone. "
Cap-and-trade systems were developed to reduce the use of CFCs.,(A) true (B) false,B,"The problems of ozone loss and global warming were unknown in 1970. When they were discovered, worldwide efforts were made to reduce CFCs and carbon dioxide emissions. "
Carbon is sequestered naturally by forests.,(A) true (B) false,A,"Human actions are influencing the carbon cycle. Burning of fossil fuels releases the carbon dioxide that was stored in ancient plants. Carbon dioxide is a greenhouse gas and is a cause of global warming. Forests are also being destroyed. Trees may be cut down for their wood, or they may be burned to clear the land for farming. Burning wood releases more carbon dioxide into the atmosphere. You can see how a tropical rainforest was cleared for farming in Figure 18.12. With forests shrinking, there are fewer trees to remove carbon dioxide from the air. This makes the greenhouse effect even worse. "
The worlds greatest producer of greenhouse gases is the U.S.,(A) true (B) false,A,"The United States has long been the largest emitter of greenhouse gases, with about 20% of total emissions in 2004. As a result of Chinas rapid economic growth, its emissions surpassed those of the United States in 2008. However, its also important to keep in mind that the United States has only about one-fifth the population of China. Whats the significance of this? The average United States citizen produces far more greenhouse gas emissions than the average Chinese person. "
worldwide agreement on air pollution that focuses on CFCs,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,E,"The Montreal Protocol is a worldwide agreement on air pollution. It focuses on CFCs. It was signed by many countries in 1987. It controls almost 100 chemicals that can damage the ozone layer. Its aim is to return the ozone layer to its normal state. The Montreal Protocol has been effective in controlling CFCs. By 1995, few CFCs were still being used. But the ozone hole kept growing for several years after that because of the CFCs already in the atmosphere. It peaked in 2006. Since then, it has been somewhat smaller. "
device that changes pollutants in exhaust gases to non-toxic compounds,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,B,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
worldwide agreement on air pollution that focuses on greenhouse gases,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,F,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
device that filters pollutants from exhaust gases,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,A,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
U.S. law that regulates six major air pollutants,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,G,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
removing carbon dioxide from the atmosphere and storing it in another form,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,D,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
system of limits and allowances on carbon dioxide emissions that can be exchanged between nations,(A) scrubber (B) catalytic converter (C) cap-and-trade (D) carbon sequestration (E) Montreal Protocol (F) Kyoto Protocol (G) Clean Air Act,C,"The Kyoto Protocol is another worldwide agreement on air pollution. It was passed in 1997. The Protocol focuses on controlling greenhouse gas emissions. Its aim is to control global warming. Carbon dioxide is the main greenhouse gas causing global warming. There are several possible ways to reduce carbon dioxide emissions. They include cap-and-trade systems, carbon taxes, and carbon sequestration In a cap-and-trade system, each nation is given a cap, or upper limit, on carbon dioxide emissions. If a nation needs to go over its cap, it can trade with another nation that is below its cap. Figure 22.16 shows how this works. Carbon taxes are taxes placed on gasoline and other products that produce carbon dioxide. The taxes encourage people to use less fossil fuel, which reduces carbon dioxide emissions. Carbon sequestration is any way of removing carbon dioxide from the atmosphere and storing it in another form. Carbon is sequestered naturally by forests. Trees take in carbon dioxide for photosynthesis. Artificial methods of sequestering carbon underground are being researched. The Kyoto Protocol has not been as successful as the Montreal Protocol. One reason is that the worlds biggest producer of greenhouse gases, the U.S., did not sign the Kyoto Protocol. Of the nations that signed it, few are "
Light travels as vibrating electric and magnetic fields.,(A) true (B) false,A,"Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves is called the electromagnetic spectrum. It is outlined in the following Figure 1.1. "
To view the stars in the night sky you should use,(A) an electron microscope (B) a refracting telescope (C) a magnifying glass (D) a radio telescope,B,"Galileos telescope got people to think about the solar system in the right way. Modern tools have also transformed our way of thinking about the universe. Imagine this: Today you can see all of the things Galileo saw using a good pair of binoculars. You can see sunspots if you have special filters on the lenses. (Never look directly at the Sun without using the proper filters!) With the most basic telescope, you can see polar caps on Mars, the rings of Saturn, and bands in the atmosphere of Jupiter. You can see many times more stars with a telescope than without a telescope. Still, stars seen in a telescope look like single points of light. They are so far away. Only the red supergiant star Betelgeuse is large enough to appear as a disk. Except for our Sun, of course. Today, astronomers attach special instruments to telescopes. This allows them to collect a wide variety of data. The data is fed into computers so that it can be studied. An astronomer may take weeks to analyze all of the data collected from just a single night! "
All telescopes work by gathering and focusing visible light.,(A) true (B) false,B,"Galileos telescope got people to think about the solar system in the right way. Modern tools have also transformed our way of thinking about the universe. Imagine this: Today you can see all of the things Galileo saw using a good pair of binoculars. You can see sunspots if you have special filters on the lenses. (Never look directly at the Sun without using the proper filters!) With the most basic telescope, you can see polar caps on Mars, the rings of Saturn, and bands in the atmosphere of Jupiter. You can see many times more stars with a telescope than without a telescope. Still, stars seen in a telescope look like single points of light. They are so far away. Only the red supergiant star Betelgeuse is large enough to appear as a disk. Except for our Sun, of course. Today, astronomers attach special instruments to telescopes. This allows them to collect a wide variety of data. The data is fed into computers so that it can be studied. An astronomer may take weeks to analyze all of the data collected from just a single night! "
"If you see a star that is 30,000 light years away, you are viewing it as it",(A) appears right now (B) appeared 1 light year ago (C) appeared 30 (D) 000 years ago (E) d appeared when it formed,C,"When we look at stars and galaxies, we are seeing over great distances. More importantly, we are also seeing back in time. When we see a distant galaxy, we are actually seeing how the galaxy used to look. For example, the Andromeda Galaxy, shown in Figure 23.1, is about 2.5 million light-years from Earth. When you see an image of the galaxy what are you seeing? You are seeing the galaxy as it was 2.5 million years ago! Since scientists can look back in time they can better understand the Universes history. Check out http://science.n "
Visible light includes all the colors of the rainbow.,(A) true (B) false,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
An electromagnetic wave,(A) has an electric field and a magnetic field (B) oscillates between high and low energy values (C) is visible to the human eye (D) all of these,A,"Light is one type of electromagnetic radiation. Light is energy that travels in the form of an electromagnetic wave. Figure 23.2 shows a diagram of an electromagnetic wave. An electromagnetic (EM) wave has two parts: an electric field and a magnetic field. The electric and magnetic fields vibrate up and down, which makes the wave. The wavelength is the horizontal distance between two of the same points on the wave, like wave crest to wave crest. A waves frequency measures the number of wavelengths that pass a given point every second. As wavelength increases, frequency decreases. This means that as wavelengths get shorter, more waves move past a particular spot in the same amount of time. "
Visible light is,(A) a small part of the electromagnetic spectrum (B) the only wavelengths that come from most stars (C) best for observing astronomical objects (D) all of these,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
The only radiation emitted by the sun is visible light.,(A) true (B) false,B,"Most of the energy that reaches the Earths surface comes from the Sun (Figure 1.1). About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths. "
The light from distant stars is very old by the time it reaches Earth.,(A) true (B) false,A,"We need a really big unit to measure distances out in space because distances between stars are so great. A light- year, 9.5 trillion kilometers (5.9 trillion miles), is the distance that light travels in one year. Thats a long way! Out in space, its actually a pretty short distance. Proxima Centauri is the closest star to us after the Sun. This near neighbor is 4.22 light-years away. That means the light from Proxima Centauri takes 4.22 years to reach us. Our galaxy, the Milky Way Galaxy, is about 100,000 light-years across. So it takes light 100,000 years to travel from one side of the galaxy to the other! It turns out that even 100,000 light years is a short distance. The most distant galaxies we have detected are more than 13 billion light-years away. Thats over a hundred-billion-trillion kilometers! "
The Greeks knew that planets were different from stars because they,(A) are larger and brighter (B) move in the opposite direction (C) are not included in any constellations (D) wander across the background of the other stars,D,"The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD. "
The largest optical telescopes today are refracting telescopes.,(A) true (B) false,B,"Humans have been making and using magnifying lenses for thousands of years. The first telescope was built by Galileo in 1608. His telescope used two lenses to make distant objects appear both nearer and larger. Telescopes that use lenses to bend light are called refracting telescopes, or refractors (Figure 23.4). The earliest telescopes were all refractors. Many amateur astronomers still use refractors today. Refractors are good for viewing details within our solar system. Craters on the surface of Earths Moon or the rings around Saturn are two such details. Around 1670, Sir Isaac Newton built a different kind of telescope. Newtons telescope used curved mirrors instead of lenses to focus light. This type of telescope is called a reflecting telescope, or reflector (see Figure 23.5). The mirrors in a reflecting telescope are much lighter than the heavy glass lenses in a refractor. This is important because a refracting telescope must be much stronger to support the heavy glass. Its much easier to precisely make mirrors than to precisely make glass lenses. For that reason, reflectors can be made larger than refractors. Larger telescopes can collect more light. This means that they can study dimmer or more distant objects. The largest optical telescopes in the world today are reflectors. Telescopes can also be made to use both lenses and mirrors. For more on how telescopes were developed, visit http://galileo.rice.edu/sci/instruments/telescope.html . "
Radio telescopes look like satellite dishes.,(A) true (B) false,A,"Radio telescopes collect radio waves. These telescopes are even larger telescopes than reflectors. Radio telescopes look a lot like satellite dishes. In fact, both are designed to collect and focus radio waves or microwaves from space. The largest single radio telescope in the world is at the Arecibo Observatory in Puerto Rico (see Figure 23.6). This telescope is located in a natural sinkhole. The sinkhole formed when water flowing underground dissolved the limestone. This telescope would collapse under its own weight if it were not supported by the ground. There is a big disadvantage to this design. The telescope can only observe the part of the sky that happens to be overhead at a given time. A group of radio telescopes can be linked together with a computer. The telescopes observe the same object. The computer then combines the data from each telescope. This makes the group function like one single telescope. An example is shown in Figure 23.7. To learn more about radio telescopes and radio astronomy in general, go to "
The Hubble telescope is the only space telescope ever placed in orbit.,(A) true (B) false,B,"Incredible images have come from the Hubble Space Telescope (HST). Even more incredible scientific discoveries have come from HST. The Hubble was the first telescope in space. It was put into orbit by the space shuttle Discovery in 1990. Since then, four shuttle missions have gone to the Hubble to make repairs and upgrades. The last repair mission to the Hubble happened in 2009. An example of a HST image is in Figure 23.28, "
Galileo observed that Venus has phases like the moon.,(A) true (B) false,A,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
Galileos observations supported the theory that planets revolve around the sun.,(A) true (B) false,A,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
A light year is a measure of time.,(A) true (B) false,B,"Astronomers use light years as the unit to describe distances in space. Remember that a light year is the distance light travels in one year. How do astronomers measure the distance to stars? For stars that are close to us, they measure shifts in their position over time. This is called parallax. For distant stars, they use the stars brightness. For example, if a star is like the Sun, it should be about as bright as the Sun. They then figure out the stars distance from Earth by measuring how much less bright it is than expected. "
type of electromagnetic wave with the highest frequency,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,A,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
The most distant objects are viewed with radio waves.,(A) true (B) false,B,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
number of waves that pass a given point per second,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,F,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
type of electromagnetic wave with the longest wavelength,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,D,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
Radio telescopes can be linked together to gather more data on a space object.,(A) true (B) false,A,"Radio telescopes collect radio waves. These telescopes are even larger telescopes than reflectors. Radio telescopes look a lot like satellite dishes. In fact, both are designed to collect and focus radio waves or microwaves from space. The largest single radio telescope in the world is at the Arecibo Observatory in Puerto Rico (see Figure 23.6). This telescope is located in a natural sinkhole. The sinkhole formed when water flowing underground dissolved the limestone. This telescope would collapse under its own weight if it were not supported by the ground. There is a big disadvantage to this design. The telescope can only observe the part of the sky that happens to be overhead at a given time. A group of radio telescopes can be linked together with a computer. The telescopes observe the same object. The computer then combines the data from each telescope. This makes the group function like one single telescope. An example is shown in Figure 23.7. To learn more about radio telescopes and radio astronomy in general, go to "
horizontal distance between the same points on adjacent waves,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,E,"Wavelength is one way of measuring the size of waves. It is the distance between two corresponding points on adjacent waves, and it is usually measured in meters. How it is measured is a little different for transverse and longitudinal waves. In a transverse wave, particles of the medium vibrate up and down at right angles to the direction that the wave travels. The wavelength of a transverse wave can be measured as the distance between two adjacent crests, or high points, as shown in the Figure 1.1. In a longitudinal wave, particles of matter vibrate back and forth in the same direction that the wave travels. The wavelength of a longitudinal wave can be measured as the distance between two adjacent compressions, as shown in the Figure 1.2. Compressions are the places where particles of the medium crowd close together as the energy of the wave passes through. "
"The longer the wavelength, the higher the frequency.",(A) true (B) false,A,The wavelength of a wave is related to the waves energy. Short-wavelength waves have more energy than long- wavelength waves of the same amplitude. (Amplitude is a measure of how far particles of the medium move up and down or back and forth when a wave passes through them.) You can see examples of transverse waves with shorter and longer wavelengths in the Figure 1.3. A: Violet light has the greatest energy because it has the shortest wavelength. 
Space telescopes are able to gather more types of waves than land-based telescopes.,(A) true (B) false,B,"Telescopes on Earth all have one big problem: Incoming light must pass through the atmosphere. This blocks some wavelengths of radiation. Also, motion in the atmosphere distorts light. You see this when you see stars twinkling in the night sky. Many observatories are built on high mountains. There is less air above the telescope, so there is less interference from the atmosphere. Space telescopes avoid such problems completely since they orbit outside the atmosphere. The Hubble Space Telescope is the best known space telescope. Hubble is shown in Figure 23.8. Hubble began operations in 1994. Since then it has provided huge amounts of data. The telescope has helped astronomers answer many of the biggest questions in astronomy. The National Aeronautics and Space Administration (NASA) has placed three other major space telescopes in orbit. Each uses a different part of the electromagnetic spectrum. The James Webb Space Telescope will launch in 2014. The telescope will replace the aging Hubble. To learn more about NASAs great observatories, check out "
device that collects and focuses radio waves from space,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,G,"Radio telescopes collect radio waves. These telescopes are even larger telescopes than reflectors. Radio telescopes look a lot like satellite dishes. In fact, both are designed to collect and focus radio waves or microwaves from space. The largest single radio telescope in the world is at the Arecibo Observatory in Puerto Rico (see Figure 23.6). This telescope is located in a natural sinkhole. The sinkhole formed when water flowing underground dissolved the limestone. This telescope would collapse under its own weight if it were not supported by the ground. There is a big disadvantage to this design. The telescope can only observe the part of the sky that happens to be overhead at a given time. A group of radio telescopes can be linked together with a computer. The telescopes observe the same object. The computer then combines the data from each telescope. This makes the group function like one single telescope. An example is shown in Figure 23.7. To learn more about radio telescopes and radio astronomy in general, go to "
device that gathers and magnifies visible light from space,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,C,"Galileos telescope got people to think about the solar system in the right way. Modern tools have also transformed our way of thinking about the universe. Imagine this: Today you can see all of the things Galileo saw using a good pair of binoculars. You can see sunspots if you have special filters on the lenses. (Never look directly at the Sun without using the proper filters!) With the most basic telescope, you can see polar caps on Mars, the rings of Saturn, and bands in the atmosphere of Jupiter. You can see many times more stars with a telescope than without a telescope. Still, stars seen in a telescope look like single points of light. They are so far away. Only the red supergiant star Betelgeuse is large enough to appear as a disk. Except for our Sun, of course. Today, astronomers attach special instruments to telescopes. This allows them to collect a wide variety of data. The data is fed into computers so that it can be studied. An astronomer may take weeks to analyze all of the data collected from just a single night! "
unit for measuring the vast distances of space,(A) gamma ray (B) light-year (C) optical telescope (D) radio wave (E) wavelength (F) wave frequency (G) radio telescope,B,"Astronomers use light years as the unit to describe distances in space. Remember that a light year is the distance light travels in one year. How do astronomers measure the distance to stars? For stars that are close to us, they measure shifts in their position over time. This is called parallax. For distant stars, they use the stars brightness. For example, if a star is like the Sun, it should be about as bright as the Sun. They then figure out the stars distance from Earth by measuring how much less bright it is than expected. "
The speed of light through space is,(A) 300 thousand m/s (B) 3 million m/s (C) 30 million m/s (D) 300 million m/s,D,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
"The ancient Greeks observed that some stars moved across the background of other stars. They named these stars wanderers. Today, we call them",(A) moons (B) planets (C) galaxies (D) constellations,B,"Humans have been studying the night sky for thousands of years. Knowing the motions of stars helped people keep track of seasons. With this information they could know when to plant crops. Stars were so important that the patterns they made in the sky were named. These patterns are called constellations. Even now, constellations help astronomers know where they are looking in the night sky. The ancient Greeks carefully observed the locations of stars in the sky. They noticed that some of the stars moved across the background of other stars. They called these bright spots in the sky planets. The word in Greek means wanderers. Today we know that the planets are not stars. They are objects in the solar system that orbit the Sun. Ancient astronomers made all of their observations without the aid of a telescope. "
The hottest stars emit primarily,(A) radio waves (B) microwaves (C) visible light (D) X rays and gamma rays,D,"Stars are made mostly of hydrogen and helium, which are packed so densely in a star that in the stars center the pressure is great enough to initiate nuclear fusion reactions. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom. Although nuclear fusion reactions require a lot of energy to get started, once they are going they produce enormous amounts of energy (Figure 1.1). In a star, the energy from fusion reactions in the core pushes outward to balance the inward pull of gravity. This energy moves outward through the layers of the star until it finally reaches the stars outer surface. The outer layer of the star glows brightly, sending the energy out into space as electromagnetic radiation, including visible light, heat, ultraviolet light, and radio waves (Figure 1.2). "
The earliest telescopes were,(A) reflecting telescopes (B) refracting telescopes (C) radio telescopes (D) none of the above,B,"Humans have been making and using magnifying lenses for thousands of years. The first telescope was built by Galileo in 1608. His telescope used two lenses to make distant objects appear both nearer and larger. Telescopes that use lenses to bend light are called refracting telescopes, or refractors (Figure 23.4). The earliest telescopes were all refractors. Many amateur astronomers still use refractors today. Refractors are good for viewing details within our solar system. Craters on the surface of Earths Moon or the rings around Saturn are two such details. Around 1670, Sir Isaac Newton built a different kind of telescope. Newtons telescope used curved mirrors instead of lenses to focus light. This type of telescope is called a reflecting telescope, or reflector (see Figure 23.5). The mirrors in a reflecting telescope are much lighter than the heavy glass lenses in a refractor. This is important because a refracting telescope must be much stronger to support the heavy glass. Its much easier to precisely make mirrors than to precisely make glass lenses. For that reason, reflectors can be made larger than refractors. Larger telescopes can collect more light. This means that they can study dimmer or more distant objects. The largest optical telescopes in the world today are reflectors. Telescopes can also be made to use both lenses and mirrors. For more on how telescopes were developed, visit http://galileo.rice.edu/sci/instruments/telescope.html . "
The main reason that space telescopes can gather more information than telescopes on Earths surface is that space telescopes are,(A) closer to objects in space (B) above Earths atmosphere (C) optical telescopes (D) two of the above,B,"Telescopes on Earth all have one big problem: Incoming light must pass through the atmosphere. This blocks some wavelengths of radiation. Also, motion in the atmosphere distorts light. You see this when you see stars twinkling in the night sky. Many observatories are built on high mountains. There is less air above the telescope, so there is less interference from the atmosphere. Space telescopes avoid such problems completely since they orbit outside the atmosphere. The Hubble Space Telescope is the best known space telescope. Hubble is shown in Figure 23.8. Hubble began operations in 1994. Since then it has provided huge amounts of data. The telescope has helped astronomers answer many of the biggest questions in astronomy. The National Aeronautics and Space Administration (NASA) has placed three other major space telescopes in orbit. Each uses a different part of the electromagnetic spectrum. The James Webb Space Telescope will launch in 2014. The telescope will replace the aging Hubble. To learn more about NASAs great observatories, check out "
Which of the following discoveries as made by Galileo with a telescope?,(A) Earth has a moon (B) The moon has craters (C) Venus has moons (D) all of the above,B,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
The spectrum of light from a star can be used to learn the stars,(A) speed (B) direction (C) temperature (D) all of the above,D,"A spectrometer is a special tool that astronomers commonly use. Spectrometers allow them to study the light from a star or galaxy. A spectrometer produces a spectrum, like the one shown in Figure 23.11. A prism breaks light into all its colors. Gases from the outer atmosphere of a star absorb light. This forms dark lines in the spectrum. These dark lines reveal what elements the star contains. Astronomers use the spectrum to learn even more about the star. One thing they learn is how hot the star is. They also learn the direction the star is going and how fast. By carefully studying light from many stars, astronomers know how stars evolve. They have learned about the distribution and kinds of matter found throughout the universe. They even know something about how the universe might have formed. To find out what you can expect to see when looking through a telescope, check out "
Voyager 1 is the first human-made object to,(A) leave Earths orbit (B) orbit the Sun (C) leave interstellar space (D) leave the solar system,D,"Both the United States and the Soviet Union sent space probes to other planets. A space probe is an unmanned spacecraft. The craft collects data by flying near or landing on an object in space. This could be a planet, moon, asteroid, or comet. The USSR sent several probes to Venus in the Venera missions. Some landed on the surface and sent back data. The U.S. sent probes to Mercury, Venus, and Mars in the Mariner missions. Two probes landed on Mars during the Viking missions. The U.S. also sent probes to the outer solar system. These probes conducted fly-bys of Jupiter, Saturn, Uranus, and Neptune. The Pioneer and Voyager probes are now out beyond the edges of our solar system. We have lost contact with the two Pioneer probes. We hope to maintain contact with the two Voyager probes until at least 2020. "
Which of the following is one of Newtons Laws of Motion?,(A) To every action (B) there is an equal and opposite reaction (C) b An object in motion will remain in motion forever and always (D) c Every object is attracted to every other object proportionately to its volume (E) d Gravity equals mass times acceleration,A,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
A rocket has multiple stages so that it,(A) can take humans into space (B) is able to orbit Earth (C) reduces the rockets weight in steps (D) none of these,C,"For centuries, rockets were powered by gunpowder or other solid fuels. These rockets could travel only short distances. Around the turn of the 20th century, several breakthroughs took place. These breakthroughs led to rockets that could travel beyond Earth. Liquid fuel gave rockets enough power to escape Earths gravity (Figure 23.14). By using multiple stages, empty fuel containers could drop away. This reduced the mass of the rocket so that it could fly higher. Rockets were used during World War II. The V2 was the first human-made object to travel high enough to be considered in space (Figure 23.15). Its altitude was 176 km (109 miles) above Earths surface. Wernher von Braun was a German rocket scientist. After he fled Germany in WWII, he helped the United States develop missile weapons. After the war, von Braun worked for NASA. He designed the Saturn V rocket (Figure "
Which two countries were involved in the space race?,(A) China India (B) USA and USSR (C) Brazil USSR (D) USA,B,"In response to Sputnik program, the U.S. launched two satellites. Explorer I was launched on January 31, 1958 and Vanguard 1 on March 17, 1958. National Aeronautics and Space Administration (NASA) was established that same year. The race was on! On April 12, 1961, a Soviet cosmonaut became the first human in space and in orbit. Less than one month later May 5, 1961 the U.S. sent its first astronaut into space: Alan Shepherd. The first American in orbit was John Glenn, in February 1962. And on it went. "
"For a rocket to enter Earth orbit, it must be launched",(A) at the right speed (B) from the right location (C) straight up (D) all of these,C,One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. There are more and more artificial satellites orbiting Earth all the time. They all get into space using some sort of rocket. 
Humans first reached space at the beginning of the 20th century.,(A) true (B) false,B,Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. 
Rockets were developed before scientists knew how they worked.,(A) true (B) false,A,"Rockets were used for centuries before anyone could explain how they worked. The theory came about in 1687. Isaac Newton (16431727) described three basic laws of motion, now referred to as Newtons Laws of Motion: 1. An object in motion will remain in motion unless acted upon by a force. 2. Force equals mass multiplied by acceleration. 3. To every action, there is an equal and opposite reaction. Which of these three best explains how a rocket works? Newtons third law of motion. When a rockets propulsion pushes in one direction, the rocket moves in the opposite direction, as seen in the Figure 23.12. For a long time, many people believed that a rocket wouldnt work in space. There would be nothing for the rocket to push against. But they do work! Fuel is ignited in a chamber. The gases in the chamber explode. The explosion creates pressure that forces the gases out of one side of the rocket. The rocket moves in the opposite direction, as shown in Figure 23.13. The force pushing the rocket is called thrust. "
The invention of gunpowder allowed rockets to travel to space.,(A) true (B) false,B,Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. 
Only two nations have put a human on the moon: the U.S. and China.,(A) true (B) false,B,"On May 25, 1961, President John F. Kennedy challenged the U.S. Congress: I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him back safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. The Soviets were also trying to reach the Moon. Who would win? The answer came eight years after Kennedys challenge, on July 20, 1969. NASAs Apollo 11 mission put astronauts Neil Armstrong and Buzz Aldrin on the Moon, as shown in Figure 23.21. A total of five American missions put astronauts on the Moon. The last was Apollo 17. This mission landed on December 11, 1972. No other country has yet put a person on the Moon. Today, most space missions are done by "
The first use of rockets in space was to land astronauts on the moon.,(A) true (B) false,B,"On May 25, 1961, President John F. Kennedy challenged the U.S. Congress: I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him back safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. The Soviets were also trying to reach the Moon. Who would win? The answer came eight years after Kennedys challenge, on July 20, 1969. NASAs Apollo 11 mission put astronauts Neil Armstrong and Buzz Aldrin on the Moon, as shown in Figure 23.21. A total of five American missions put astronauts on the Moon. The last was Apollo 17. This mission landed on December 11, 1972. No other country has yet put a person on the Moon. Today, most space missions are done by "
A satellite is an object that orbits a smaller object.,(A) true (B) false,A,One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. There are more and more artificial satellites orbiting Earth all the time. They all get into space using some sort of rocket. 
Most satellites launch themselves into orbit.,(A) true (B) false,B,Satellites orbit high above the Earth in several ways. Different orbits are important for viewing different things about the planet. 
Thousands of satellites are in orbit around Earth.,(A) true (B) false,A,Satellites orbit high above the Earth in several ways. Different orbits are important for viewing different things about the planet. 
It was only 12 years between when the first artificial satellite was launched and Neil Armstrong walked,(A) true (B) false,A,"In response to Sputnik program, the U.S. launched two satellites. Explorer I was launched on January 31, 1958 and Vanguard 1 on March 17, 1958. National Aeronautics and Space Administration (NASA) was established that same year. The race was on! On April 12, 1961, a Soviet cosmonaut became the first human in space and in orbit. Less than one month later May 5, 1961 the U.S. sent its first astronaut into space: Alan Shepherd. The first American in orbit was John Glenn, in February 1962. And on it went. "
Landsat satellites make detailed images of continents and coasts.,(A) true (B) false,A,"Dozens of satellites collect data about the Earth. One example is NASAs Landsat satellites. These satellites make detailed images of Earths continents and coastal areas. Other satellites study the oceans, atmosphere, polar ice sheets, and other Earth systems. This data helps us to monitor climate change. Other long-term changes in the planet are also best seen from space. Satellite images help scientists understand how Earths systems affect one another. Different satellites monitor different wavelengths of energy, as in Figure 23.19. "
An object can go into orbit because of the law of conservation of momentum.,(A) true (B) false,B,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Newtons Third Law of Motion helps explain how a rocket will travel in space.,(A) true (B) false,A,"A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. "
Imaging satellites are placed in high orbits over Earth.,(A) true (B) false,B,Satellites orbit high above the Earth in several ways. Different orbits are important for viewing different things about the planet. 
Alan Shepherd was the first astronaut to walk on the Moon.,(A) true (B) false,B,"In response to Sputnik program, the U.S. launched two satellites. Explorer I was launched on January 31, 1958 and Vanguard 1 on March 17, 1958. National Aeronautics and Space Administration (NASA) was established that same year. The race was on! On April 12, 1961, a Soviet cosmonaut became the first human in space and in orbit. Less than one month later May 5, 1961 the U.S. sent its first astronaut into space: Alan Shepherd. The first American in orbit was John Glenn, in February 1962. And on it went. "
The U.S. has landed space probes on Mars.,(A) true (B) false,A,"Both the United States and the Soviet Union sent space probes to other planets. A space probe is an unmanned spacecraft. The craft collects data by flying near or landing on an object in space. This could be a planet, moon, asteroid, or comet. The USSR sent several probes to Venus in the Venera missions. Some landed on the surface and sent back data. The U.S. sent probes to Mercury, Venus, and Mars in the Mariner missions. Two probes landed on Mars during the Viking missions. The U.S. also sent probes to the outer solar system. These probes conducted fly-bys of Jupiter, Saturn, Uranus, and Neptune. The Pioneer and Voyager probes are now out beyond the edges of our solar system. We have lost contact with the two Pioneer probes. We hope to maintain contact with the two Voyager probes until at least 2020. "
circular or elliptical path around an object,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,F,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
force that pushes a rocket,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,B,"A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. "
object that orbits a larger object,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,D,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
largest artificial satellite,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,E,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
U.S. agency in charge of space exploration,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,G,Budget concerns have impacted NASA in recent years. Many scientists have come together to discuss the goals of the U.S. space program. Some would like to further explore the Moon. Others are interested in landing on Mars. A variety of destinations in the inner solar system may also be visited. Private aerospace companies will play more of a role in the coming years. 
vehicle pushed in one direction by particles flying out of it in the opposite direction,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,A,"A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. "
spacecraft that explores space without people aboard,(A) rocket (B) thrust (C) space probe (D) satellite (E) ISS (F) orbit (G) NASA,C,The disasters have caused NASA to focus on developing unmanned missions. Missions without a crew are less expensive and less dangerous. These missions still provide a great deal of valuable information. 
Rockets were first used as early as the,(A) 13th century (B) 17th century (C) 19th century (D) 20th century,A,Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. 
Isaac Newtons third law of motion states that,(A) an object in motion will remain in motion unless acted upon by a force (B) every object in the universe is attracted to every other object (C) for every action (D) there is an equal and opposite reaction (E) d force equals mass multiplied by acceleration,C,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
The first rocket to travel into space was used during,(A) the 1200s (B) World War I (C) World War II (D) the space race,C,Humans did not reach space until the second half of the 20th century. They needed somehow to break past Earths gravity. A rocket moves rapidly in one direction. The device is propelled by particles flying out of it at high speed in the other direction. There are records of the Chinese using rockets in war against the Mongols as early as the 13th century. The Mongols then used rockets to attack Eastern Europe. Early rockets were also used to launch fireworks. 
Satellites stay in orbit because of,(A) thrust (B) gravity (C) rockets (D) propulsion,B,"Why do satellites stay in orbit? Why dont they crash into Earth due to the planets gravity? Newtons law of universal gravitation describes what happens. Every object in the universe is attracted to every other object. Gravity makes an apple fall to the ground. Gravity also keeps you from floating away into the sky. Gravity holds the Moon in orbit around Earth. It keeps Earth in orbit around the Sun. Newton used an example to explain how gravity makes orbiting possible. Imagine a cannonball launched from a high mountain, as shown in Figure 23.17. If the cannonball is launched at a slow speed, it will fall back to Earth. This is shown as paths (A) and (B). Something different happens if the cannonball is launched at a fast speed. The Earth below curves away at the same rate that the cannonball falls. The cannonball then goes into a circular orbit, as in path (C). If the cannonball is launched even faster, it could go into an elliptical orbit (D). It might even leave Earths gravity and go into space (E). Unfortunately, Newtons idea would not work in real life. A cannonball launched at a fast speed from Mt. Everest would not go into orbit. The cannonball would burn up in the atmosphere. However, a rocket can launch straight up, then steer into orbit. It wont burn up in the orbit. A rocket can carry a satellite above the atmosphere and then release the satellite into orbit. "
The Global Positioning System (GPS) uses,(A) communications satellites (B) navigational satellites (C) weather satellites (D) imaging satellites,B,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
A satellite in a low orbit,(A) travels from north to south over Earths poles (B) orbits Earth at the same rate that Earth spins (C) moves in the same direction that Earth rotates (D) remains over the same place on Earths surface,A,Satellites have different views depending on their orbit. Satellites may be put in a low orbit. These satellites orbit from north to south over the poles. These satellites view a different part of Earth each time they circle. Imaging and weather satellites need this type of view. Satellite may be placed so that they orbit at the same rate the Earth spins. The satellite then remains over the same location on the surface. Communications satellites are often placed in these orbits. 
The first American to orbit Earth was,(A) Neil Armstrong (B) Buzz Aldrin (C) John Glenn (D) Alan Shepherd,C,"In response to Sputnik program, the U.S. launched two satellites. Explorer I was launched on January 31, 1958 and Vanguard 1 on March 17, 1958. National Aeronautics and Space Administration (NASA) was established that same year. The race was on! On April 12, 1961, a Soviet cosmonaut became the first human in space and in orbit. Less than one month later May 5, 1961 the U.S. sent its first astronaut into space: Alan Shepherd. The first American in orbit was John Glenn, in February 1962. And on it went. "
"While the U.S. flew missions to the moon in the early 1970s, the Soviets worked to build space",(A) orbiters (B) shuttles (C) stations (D) rovers,C,"While the United States continued missions to the Moon in the early 1970s, the Soviets worked to build a space station. A space station is a large spacecraft. People can live on this craft for a long period of time. "
The International Space Station has had people on board since __________.,(A) 1969 (B) 1989 (C) 2000 (D) 2008,C,"The International Space Station, shown in Figure 23.24 is a joint project between the space agencies of many nations These include the United States (NASA), Russia (RKA), Japan (JAXA), Canada (CSA), several European countries (ESA) and the Brazilian Space Agency. The International Space Station is a very large station. It has many different sections and is still being assembled. The station has had people on board since 2000. American space shuttles deliver most of the supplies and equipment to the station. Russian Soyuz spacecraft carry people. The primary purpose of the station is scientific research. This is important because the station has a microgravity environment. Experiments are done in the fields of biology, chemistry, physics, physiology and medicine. "
The Soviet Salyut space stations were used for,(A) military purposes (B) scientific research (C) astronaut transport (D) two of the above,D,"Between 1971 and 1982, the Soviets put a total of seven Salyut space stations into orbit. Figure 23.22 shows the last of these, Salyut 7. These were all temporary stations. They were launched and later inhabited by a human crew. Three of the Salyut stations were used for secret military purposes. The others were used to study the problems of living in space. Cosmonauts aboard the stations performed a variety of experiments in astronomy, biology, and Earth science. Salyut 6 and Salyut 7 each had two docking ports. One crew could dock a spacecraft to one end. A replacement crew could dock to the other end. The U.S. only launched one space station during this time. It was called Skylab. Skylab was launched in May 1973. Three crews visited Skylab, all within its first year in orbit. Skylab was used to study the effects of staying in space for long period. Devices on board were and for studying the Sun. Skylab reentered Earths atmosphere in 1979, sooner than expected. "
A space station is,(A) launched and constructed in pieces (B) designed for defense purposes (C) home to astronauts from one country at a time (D) none of these,A,"While the United States continued missions to the Moon in the early 1970s, the Soviets worked to build a space station. A space station is a large spacecraft. People can live on this craft for a long period of time. "
The first space station designed for long-term use was,(A) Salyut 7 (B) Skylab (C) Mir (D) none of the above,C,The first space station designed for long-term use was the Mir space station (Figure 23.23). Mir was launched in several separate pieces. These pieces were put together in space. Mir holds the current record for the longest continued presence in space. There were people living on Mir continuously for almost 10 years! Mir was the first major space project in which the United States and Russia worked together. American space shuttles transported supplies and people to and from Mir. American astronauts lived on Mir for many months. This cooperation allowed the two nations to learn from each other. The U.S. learned about Russias experiences with long-duration space flights. Mir was taken out of orbit in 2001. It fell into the Pacific Ocean. 
What features make a space shuttle unique?,(A) It can explore the inner solar system (B) It can haul cargo into space (C) It can fly like an airplane (D) It can land on the moon and return,B,"NASA wanted a new kind of space vehicle. This vehicle had to be reusable. It had to able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The new vehicle was called a space shuttle, shown in Figure 23.25. There have been five space shuttles: Columbia, Challenger, Discovery, Atlantis, and Endeavor. A space shuttle has three main parts. You are probably most familiar with the orbiter. This part has wings like At the end of the mission, the orbiter re-enters Earths atmosphere. The outside heats up as it descends. Pilots have to steer the shuttle to the runway very precisely. Space shuttles usually land at Kennedy Space Center or at Edwards Air Force Base in California. The orbiter is later hauled back to Florida on the back of a jet airplane. "
"If you want to see what happened to a lake before and after a hurricane, you would use",(A) geospatial satellites (B) Landsat images (C) rovers (D) none of these,B,"To understand what satellites can do, lets look at an example. One of the deadliest hurricanes in United States history hit Galveston, Texas in 1900. The storm was first spotted at sea on Monday, August 27th , 1900. It was a tropical storm when it hit Cuba on September 3rd . By September 8th , it had intensified to a hurricane over the Gulf of Mexico. It came ashore at Galveston (Figure 2.34). Because there was not advanced warning, more than 8000 people lost their lives. Today, we have satellites with many different types of instruments that orbit the Earth. With these satellites, satellites can see hurricanes form at sea. They can follow hurricanes as they move from far out in the oceans to shore. Weather forecasters can warn people who live along the coasts. These advanced warning give people time to prepare for the storm. They can find a safe place or even evacuate the area, which helps save lives. "
Nations that have worked together on the International Space Station include,(A) US (B) Russia (C) Brazil (D) all of the above,D,"The International Space Station, shown in Figure 23.24 is a joint project between the space agencies of many nations These include the United States (NASA), Russia (RKA), Japan (JAXA), Canada (CSA), several European countries (ESA) and the Brazilian Space Agency. The International Space Station is a very large station. It has many different sections and is still being assembled. The station has had people on board since 2000. American space shuttles deliver most of the supplies and equipment to the station. Russian Soyuz spacecraft carry people. The primary purpose of the station is scientific research. This is important because the station has a microgravity environment. Experiments are done in the fields of biology, chemistry, physics, physiology and medicine. "
Most people have been carried to and from the ISS by,(A) American shuttles (B) Russian spacecraft (C) US (D) two of the above,B,"Craft designed for human spaceflight, like the Apollo missions, were very successful, but were also very expensive, could not carry much cargo, and could be used only once. To outfit the ISS, NASA needed a space vehicle that was reusable and able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The resulting spacecraft was a space shuttle, shown in (Figure 1.4). Satellites operate with solar panels for energy. A photograph of the International Space Station was taken from the space shuttle Atlantis in June 2007. Construction of the station was completed in 2011, but new pieces and experiments continue to be added. A space shuttle has three main parts. The part you are probably most familiar with is the orbiter, with wings like an airplane. When a space shuttle launches, the orbiter is attached to a huge fuel tank that contains liquid fuel. On the sides of the fuel tank are two large ""booster rockets."" All of this is needed to get the orbiter out of Earths atmosphere. Once in space, the orbiter can be used to release equipment (such as a satellite or supplies for the International Space Station), to repair existing equipment such as the Hubble Space Telescope, or to do experiments directly on board the orbiter. When the mission is complete, the orbiter re-enters Earths atmosphere and flies back to Earth more like a glider than an airplane. The Space Shuttle program did 135 missions between 1981 and 2011, when the remaining shuttles were retired. The ISS is now serviced by Russian Soyuz spacecraft. Atlantis on the launch pad in 2006. Since 1981, the space shuttle has been the United States primary vehicle for carrying people and large equipment into space. "
"Smaller solar system objects, like asteroids, may give us clues as to",(A) how the solar system formed (B) what planets are made of (C) when the solar system formed (D) all of these,D,"Astronomy and astronomers have shown that the planets in our solar system are not the only planets in the universe. Over 530 planets were known outside our solar system in 2011. And there are billions of other planets! The universe also contains black holes, other galaxies, asteroids, comets, and nebula. As big as Earth seems, the entire universe is vastly more enormous. Earth is just a tiny part of our universe. Astronomers use many tools to study things in space. Earth-orbiting telescopes view stars and galaxies from the darkness of space (Figure 1.17). They may have optical and radio telescopes to see things that the human eye cant see. Spacecraft travel great distances to send back information on faraway places. Astronomers ask a wide variety of questions. How do strong bursts of energy from the Sun, called solar flares, affect communications? How might an impact from an asteroid affect life on Earth? What are the properties of black holes? Astronomers ask bigger questions too. How was the universe created? Is there life on other planets? Are there resources on other planets that people could use? Astronomers use what Earth scientists know to make comparisons with other planets. "
Crews on U.S. space shuttles have,(A) transported materials to the ISS (B) repaired the Hubble space telescope (C) launched satellites (D) all of the above,D,"The space shuttle program has been very successful. Over 100 mission have been flown. Space shuttle missions have made many scientific discoveries. Crews have launched many satellites. There have been other great achievements in space. However, the program has also had two tragic disasters. The first came just 73 seconds after launch, on January 28, 1986. The space shuttle Challenger disintegrated in mid-air, as shown in Figure 23.27. On board were seven crew members. All of them died. One of them was Christa McAuliffe, who was to be the first teacher in space. The problem was later shown to be an O-ring. This small part was in one of the rocket boosters. Space shuttle missions were put on hold while NASA improved the safety of the shuttles. The second occurred during the takeoff of the Columbia on January 16, 2003. A small piece of insulating foam broke off the fuel tank. The foam smashed into a tile on the shuttles wing. The tile was part of the shuttles heat shield. The shield protects the shuttle from extremely high temperatures as it reenters the atmosphere. When Columbia returned to Earth on February 3, 2003, it could not withstand the high temperatures. The shuttle broke apart. Again, all seven crew members died. The space shuttle will be retired in 2011. All the remaining shuttle missions will be to the ISS. Orion will replace the shuttle. Known as a Crew Exploration Vehicle, Orion is expected to be ready by 2016. "
The Hubble space telescope was put into orbit by the,(A) space shuttle Discovery (B) Deep Impact Probe (C) Cassini mission (D) Huygens Probe,A,"Incredible images have come from the Hubble Space Telescope (HST). Even more incredible scientific discoveries have come from HST. The Hubble was the first telescope in space. It was put into orbit by the space shuttle Discovery in 1990. Since then, four shuttle missions have gone to the Hubble to make repairs and upgrades. The last repair mission to the Hubble happened in 2009. An example of a HST image is in Figure 23.28, "
space station that is a joint project of many nations,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,B,"The International Space Station, shown in Figure 23.24 is a joint project between the space agencies of many nations These include the United States (NASA), Russia (RKA), Japan (JAXA), Canada (CSA), several European countries (ESA) and the Brazilian Space Agency. The International Space Station is a very large station. It has many different sections and is still being assembled. The station has had people on board since 2000. American space shuttles deliver most of the supplies and equipment to the station. Russian Soyuz spacecraft carry people. The primary purpose of the station is scientific research. This is important because the station has a microgravity environment. Experiments are done in the fields of biology, chemistry, physics, physiology and medicine. "
any large satellite that people can live on,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,C,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
part of a space shuttle that has wings,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,G,"NASA wanted a new kind of space vehicle. This vehicle had to be reusable. It had to able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The new vehicle was called a space shuttle, shown in Figure 23.25. There have been five space shuttles: Columbia, Challenger, Discovery, Atlantis, and Endeavor. A space shuttle has three main parts. You are probably most familiar with the orbiter. This part has wings like At the end of the mission, the orbiter re-enters Earths atmosphere. The outside heats up as it descends. Pilots have to steer the shuttle to the runway very precisely. Space shuttles usually land at Kennedy Space Center or at Edwards Air Force Base in California. The orbiter is later hauled back to Florida on the back of a jet airplane. "
One purpose of the International Space Station is to conduct medical research.,(A) true (B) false,A,"Humans have a presence in space at the International Space Station (ISS) (pictured in Figure 1.3). Modern space stations are constructed piece by piece to create a modular system. The primary purpose of the ISS is scientific research, especially in medicine, biology, and physics. "
space station with the longest continuous use,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,F,The first space station designed for long-term use was the Mir space station (Figure 23.23). Mir was launched in several separate pieces. These pieces were put together in space. Mir holds the current record for the longest continued presence in space. There were people living on Mir continuously for almost 10 years! Mir was the first major space project in which the United States and Russia worked together. American space shuttles transported supplies and people to and from Mir. American astronauts lived on Mir for many months. This cooperation allowed the two nations to learn from each other. The U.S. learned about Russias experiences with long-duration space flights. Mir was taken out of orbit in 2001. It fell into the Pacific Ocean. 
Private companies are increasingly getting into space exploration.,(A) true (B) false,A,Budget concerns have impacted NASA in recent years. Many scientists have come together to discuss the goals of the U.S. space program. Some would like to further explore the Moon. Others are interested in landing on Mars. A variety of destinations in the inner solar system may also be visited. Private aerospace companies will play more of a role in the coming years. 
reusable space vehicle for carrying equipment and people to and from space,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,A,"Craft designed for human spaceflight, like the Apollo missions, were very successful, but were also very expensive, could not carry much cargo, and could be used only once. To outfit the ISS, NASA needed a space vehicle that was reusable and able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The resulting spacecraft was a space shuttle, shown in (Figure 1.4). Satellites operate with solar panels for energy. A photograph of the International Space Station was taken from the space shuttle Atlantis in June 2007. Construction of the station was completed in 2011, but new pieces and experiments continue to be added. A space shuttle has three main parts. The part you are probably most familiar with is the orbiter, with wings like an airplane. When a space shuttle launches, the orbiter is attached to a huge fuel tank that contains liquid fuel. On the sides of the fuel tank are two large ""booster rockets."" All of this is needed to get the orbiter out of Earths atmosphere. Once in space, the orbiter can be used to release equipment (such as a satellite or supplies for the International Space Station), to repair existing equipment such as the Hubble Space Telescope, or to do experiments directly on board the orbiter. When the mission is complete, the orbiter re-enters Earths atmosphere and flies back to Earth more like a glider than an airplane. The Space Shuttle program did 135 missions between 1981 and 2011, when the remaining shuttles were retired. The ISS is now serviced by Russian Soyuz spacecraft. Atlantis on the launch pad in 2006. Since 1981, the space shuttle has been the United States primary vehicle for carrying people and large equipment into space. "
first U.S. space station,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,D,"While the United States continued missions to the Moon in the early 1970s, the Soviets worked to build a space station. A space station is a large spacecraft. People can live on this craft for a long period of time. "
There are currently rovers on Venus and Mars.,(A) true (B) false,B,"We continue to explore the solar system. A rover is like a spacecraft on wheels (Figure 23.29). It can wheel around on the surface. Scientists on Earth tell it where to go. The craft then collects and sends back data from that locations. The Mars Pathfinder studied the red planet for nearly three months in 1997. Two more rovers, Spirit and Opportunity, landed on Mars in 2004. Both were only designed to last 90 days, but have lasted many times longer. Spirit sent back data until it became stuck in January 2010. Opportunity continues to explore Mars. Several spacecraft are currently in orbit, studying the Martian surface and thin atmosphere. "
first space telescope,(A) space shuttle (B) ISS (C) space station (D) Skylab (E) Hubble (F) Mir (G) orbiter,E,"Incredible images have come from the Hubble Space Telescope (HST). Even more incredible scientific discoveries have come from HST. The Hubble was the first telescope in space. It was put into orbit by the space shuttle Discovery in 1990. Since then, four shuttle missions have gone to the Hubble to make repairs and upgrades. The last repair mission to the Hubble happened in 2009. An example of a HST image is in Figure 23.28, "
The mission of NASA is to study everything in the solar system except Earth.,(A) true (B) false,B,"Astronomy and astronomers have shown that the planets in our solar system are not the only planets in the universe. Over 530 planets were known outside our solar system in 2011. And there are billions of other planets! The universe also contains black holes, other galaxies, asteroids, comets, and nebula. As big as Earth seems, the entire universe is vastly more enormous. Earth is just a tiny part of our universe. Astronomers use many tools to study things in space. Earth-orbiting telescopes view stars and galaxies from the darkness of space (Figure 1.17). They may have optical and radio telescopes to see things that the human eye cant see. Spacecraft travel great distances to send back information on faraway places. Astronomers ask a wide variety of questions. How do strong bursts of energy from the Sun, called solar flares, affect communications? How might an impact from an asteroid affect life on Earth? What are the properties of black holes? Astronomers ask bigger questions too. How was the universe created? Is there life on other planets? Are there resources on other planets that people could use? Astronomers use what Earth scientists know to make comparisons with other planets. "
The record for one crew inhabiting a space station is ten years.,(A) true (B) false,B,The first space station designed for long-term use was the Mir space station (Figure 23.23). Mir was launched in several separate pieces. These pieces were put together in space. Mir holds the current record for the longest continued presence in space. There were people living on Mir continuously for almost 10 years! Mir was the first major space project in which the United States and Russia worked together. American space shuttles transported supplies and people to and from Mir. American astronauts lived on Mir for many months. This cooperation allowed the two nations to learn from each other. The U.S. learned about Russias experiences with long-duration space flights. Mir was taken out of orbit in 2001. It fell into the Pacific Ocean. 
The Huygens space mission is studying Pluto.,(A) true (B) false,B,"For decades Pluto was a planet. But even then, scientists knew it was an unusual planet. The other outer planets are all gas giants. Pluto is small, icy and rocky. With a diameter of about 2400 kilometers, it has only about 1/5 the mass of Earths Moon. The other planets orbit in a plane. Plutos orbit is tilted. The shape of the orbit is like a long, narrow ellipse. Plutos orbit is so elliptical that sometimes it is inside the orbit of Neptune. Plutos orbit is in the Kuiper belt. We have discovered more than 200 million Kuiper belt objects. Pluto has 3 moons of its own. The largest, Charon, is big. Some scientists think that Pluto-Charon system is a double dwarf planet (Figure 25.37). Two smaller moons, Nix and Hydra, were discovered in 2005. "
The Soviet Salyut space stations were all temporary stations.,(A) true (B) false,A,"Between 1971 and 1982, the Soviets put a total of seven Salyut space stations into orbit. Figure 23.22 shows the last of these, Salyut 7. These were all temporary stations. They were launched and later inhabited by a human crew. Three of the Salyut stations were used for secret military purposes. The others were used to study the problems of living in space. Cosmonauts aboard the stations performed a variety of experiments in astronomy, biology, and Earth science. Salyut 6 and Salyut 7 each had two docking ports. One crew could dock a spacecraft to one end. A replacement crew could dock to the other end. The U.S. only launched one space station during this time. It was called Skylab. Skylab was launched in May 1973. Three crews visited Skylab, all within its first year in orbit. Skylab was used to study the effects of staying in space for long period. Devices on board were and for studying the Sun. Skylab reentered Earths atmosphere in 1979, sooner than expected. "
Skylab studied the effects of staying in space for long periods of time,(A) true (B) false,A,"Between 1971 and 1982, the Soviets put a total of seven Salyut space stations into orbit. Figure 23.22 shows the last of these, Salyut 7. These were all temporary stations. They were launched and later inhabited by a human crew. Three of the Salyut stations were used for secret military purposes. The others were used to study the problems of living in space. Cosmonauts aboard the stations performed a variety of experiments in astronomy, biology, and Earth science. Salyut 6 and Salyut 7 each had two docking ports. One crew could dock a spacecraft to one end. A replacement crew could dock to the other end. The U.S. only launched one space station during this time. It was called Skylab. Skylab was launched in May 1973. Three crews visited Skylab, all within its first year in orbit. Skylab was used to study the effects of staying in space for long period. Devices on board were and for studying the Sun. Skylab reentered Earths atmosphere in 1979, sooner than expected. "
"A space shuttle includes an orbiter, fuel tank, and booster rockets.",(A) true (B) false,A,"NASA wanted a new kind of space vehicle. This vehicle had to be reusable. It had to able to carry large pieces of equipment, such as satellites, space telescopes, or sections of a space station. The new vehicle was called a space shuttle, shown in Figure 23.25. There have been five space shuttles: Columbia, Challenger, Discovery, Atlantis, and Endeavor. A space shuttle has three main parts. You are probably most familiar with the orbiter. This part has wings like At the end of the mission, the orbiter re-enters Earths atmosphere. The outside heats up as it descends. Pilots have to steer the shuttle to the runway very precisely. Space shuttles usually land at Kennedy Space Center or at Edwards Air Force Base in California. The orbiter is later hauled back to Florida on the back of a jet airplane. "
The space shuttle program flew a total of 10 missions.,(A) true (B) false,B,"The space shuttle program has been very successful. Over 100 mission have been flown. Space shuttle missions have made many scientific discoveries. Crews have launched many satellites. There have been other great achievements in space. However, the program has also had two tragic disasters. The first came just 73 seconds after launch, on January 28, 1986. The space shuttle Challenger disintegrated in mid-air, as shown in Figure 23.27. On board were seven crew members. All of them died. One of them was Christa McAuliffe, who was to be the first teacher in space. The problem was later shown to be an O-ring. This small part was in one of the rocket boosters. Space shuttle missions were put on hold while NASA improved the safety of the shuttles. The second occurred during the takeoff of the Columbia on January 16, 2003. A small piece of insulating foam broke off the fuel tank. The foam smashed into a tile on the shuttles wing. The tile was part of the shuttles heat shield. The shield protects the shuttle from extremely high temperatures as it reenters the atmosphere. When Columbia returned to Earth on February 3, 2003, it could not withstand the high temperatures. The shuttle broke apart. Again, all seven crew members died. The space shuttle will be retired in 2011. All the remaining shuttle missions will be to the ISS. Orion will replace the shuttle. Known as a Crew Exploration Vehicle, Orion is expected to be ready by 2016. "
The last space shuttle was retired in 2001.,(A) true (B) false,B,"The space shuttle program has been very successful. Over 100 mission have been flown. Space shuttle missions have made many scientific discoveries. Crews have launched many satellites. There have been other great achievements in space. However, the program has also had two tragic disasters. The first came just 73 seconds after launch, on January 28, 1986. The space shuttle Challenger disintegrated in mid-air, as shown in Figure 23.27. On board were seven crew members. All of them died. One of them was Christa McAuliffe, who was to be the first teacher in space. The problem was later shown to be an O-ring. This small part was in one of the rocket boosters. Space shuttle missions were put on hold while NASA improved the safety of the shuttles. The second occurred during the takeoff of the Columbia on January 16, 2003. A small piece of insulating foam broke off the fuel tank. The foam smashed into a tile on the shuttles wing. The tile was part of the shuttles heat shield. The shield protects the shuttle from extremely high temperatures as it reenters the atmosphere. When Columbia returned to Earth on February 3, 2003, it could not withstand the high temperatures. The shuttle broke apart. Again, all seven crew members died. The space shuttle will be retired in 2011. All the remaining shuttle missions will be to the ISS. Orion will replace the shuttle. Known as a Crew Exploration Vehicle, Orion is expected to be ready by 2016. "
Space shuttle disasters caused NASA to focus on missions without crews.,(A) true (B) false,A,The disasters have caused NASA to focus on developing unmanned missions. Missions without a crew are less expensive and less dangerous. These missions still provide a great deal of valuable information. 
Saturns moon Titan has some of the conditions needed to support life.,(A) true (B) false,A,"Most of Saturns moons are very small, and only seven are large enough for gravity to have made them spherical. Only Titan is larger than Earths Moon at about 1.5 times its size. Titan is even larger than the planet Mercury. Scientists are interested in Titan because its atmosphere is similar to what Earths was like before life developed. Nitrogen is dominant and methane is the second most abundant gas. Titan may have a layer of liquid water and ammonia under a layer of surface ice. Lakes of liquid methane (CH4 ) and ethane (C2 H6 ) are found on Titans surface. Although conditions are similar enough to those of early Earth for scientists to speculate that extremely A color-exaggerated mosaic of Saturn and its rings taken by Cassini as Saturn eclipses the Sun. A close-up of Saturns outer C ring show- ing areas with higher particle concentra- tion and gaps. This composite image compares Saturns largest moon, Titan (right) to Earth (left). Click image to the left or use the URL below. URL: "
The Stardust mission collected dust particles from the surface of Mars.,(A) true (B) false,B,Scientists are interested in asteroids because they are representatives of the earliest solar system (Figure 1.4). Eventually asteroids could be mined for rare minerals or for construction projects in space. A few missions have studied asteroids directly. NASAs DAWN mission explored asteroid Vesta in 2011 and 2012 and will visit dwarf planet Ceres in 2015. Click image to the left or use the URL below. URL:  The NEAR Shoemaker probe took this photo as it was about to land on 433 Eros in 2001. 
Private companies will play more of role in future space missions.,(A) true (B) false,A,Budget concerns have impacted NASA in recent years. Many scientists have come together to discuss the goals of the U.S. space program. Some would like to further explore the Moon. Others are interested in landing on Mars. A variety of destinations in the inner solar system may also be visited. Private aerospace companies will play more of a role in the coming years. 
An imaginary line running through the poles of Earth is called,(A) orbit (B) pole (C) magnetic pole (D) axis,D,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
How long does it take the Earth to make one rotation on its axis?,(A) one day (B) one month (C) one year (D) one week,A,"Imagine a line passing through the center of Earth that goes through both the North Pole and the South Pole. This imaginary line is called an axis. Earth spins around its axis, just as a top spins around its spindle. This spinning movement is called Earths rotation. An observer in space will see that Earth requires 23 hours, 59 minutes, and 4 seconds to make one complete rotation on its axis. But because Earth moves around the Sun at the same time that it is rotating, the planet must turn just a little bit more to reach the same place relative to the Sun. Hence the length of a day on Earth is actually 24 hours. At the Equator, the Earth rotates at a speed of about 1,700 km per hour, but at the poles the movement speed is nearly nothing. "
How many degrees does the Earth turn in one day?,(A) 90 degrees (B) 180 degrees (C) 360 degrees (D) 1080 degrees,C,"Imagine a line passing through the center of Earth that goes through both the North Pole and the South Pole. This imaginary line is called an axis. Earth spins around its axis, just as a top spins around its spindle. This spinning movement is called Earths rotation. An observer in space will see that Earth requires 23 hours, 59 minutes, and 4 seconds to make one complete rotation on its axis. But because Earth moves around the Sun at the same time that it is rotating, the planet must turn just a little bit more to reach the same place relative to the Sun. Hence the length of a day on Earth is actually 24 hours. At the Equator, the Earth rotates at a speed of about 1,700 km per hour, but at the poles the movement speed is nearly nothing. "
What causes Earths seasons?,(A) the planets rotation (B) the planets tilt (C) the planets revolution (D) the planets orbit,B,"Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. Different areas also receive different amounts of sunlight in different seasons. What causes the seasons? The seasons are caused by the direction Earths axis is pointing relative to the Sun. The Earth revolves around the Sun once each year and spins on its axis of rotation once each day. This axis of rotation is tilted 23.5o relative to its plane of orbit around the Sun. The axis of rotation is pointed toward Polaris, the North Star. As the Earth orbits the Sun, the tilt of Earths axis stays lined up with the North Star. "
Earths magnetic field is due to,(A) the movement of metal in Earths outer core (B) a bar magnet that is lodged between the magnetic poles (C) the force of the Suns magnetic field (D) mantle convection,A,Earth is surrounded by a magnetic field (Figure 1.1) that behaves as if the planet had a gigantic bar magnet inside of it. Earths magnetic field also has a north and south pole. The magnetic field arises from the convection of molten iron and nickel metals in Earths liquid outer core. 
Earth is the only planet in the solar system known to have liquid water.,(A) true (B) false,A,"Earth is a very diverse planet, seen in Figure 25.14. Water appears as vast oceans of liquid. Water is also seen as ice at the poles or as clouds of vapor. Earth also has large masses of land. Earths average surface temperature is 14C (57F). At this temperature, water is a liquid. The oceans and the atmosphere help keep Earths surface temperatures fairly steady. Earth is the only planet known to have life. Conditions on Earth are ideal for life! The atmosphere filters out harmful radiation. Water is abundant. Carbon dioxide was available for early life forms. The evolution of plants introduced more oxygen for animals. "
All objects in the solar system have gravitational attraction to each other.,(A) true (B) false,A,"Earth and Moon orbit each other. This Earth-Moon system orbits the Sun in a regular path (Figure 24.4). Gravity is the force of attraction between all objects. Gravity keeps the Earth and Moon in their orbits. Earths gravity pulls the Moon toward Earths center. Without gravity, the Moon would continue moving in a straight line off into space. All objects in the universe have a gravitational attraction to each other (Figure 24.5). The strength of the force of gravity depends on two things. They are the mass of the objects and the distance between them. The greater the objects mass, the greater the force of attraction. As the distance between the objects increases, the force of attraction decreases. "
"If you look at Earth from the North Pole, the planet spins in a clockwise direction.",(A) true (B) false,B,"How long does it take Earth to spin once on its axis? One rotation is 24 hours. That rotation is the length of a day! Whatever time it is, the side of Earth facing the Sun has daylight. The side facing away from the Sun is dark. If you look at Earth from the North Pole, the planet spins counterclockwise. As the Earth rotates, you see the Sun moving across the sky from east to west. We often say that the Sun is rising or setting. The Sun rises in the east and sets in the west. Actually, it is the Earths rotation that makes it appear that way. The Moon and the stars at night also seem to rise in the east and set in the west. Earths rotation is also responsible for this too. As Earth turns, the Moon and stars change position in the sky. "
Earth is divided into four hemispheres.,(A) true (B) false,B,Earth formed 4.5 billion years ago. Geologists divide this time span into smaller periods. Many of the divisions mark major events in life history. 
The moon appears to rise in the east because Earth rotates from east to west.,(A) true (B) false,B,"How long does it take Earth to spin once on its axis? One rotation is 24 hours. That rotation is the length of a day! Whatever time it is, the side of Earth facing the Sun has daylight. The side facing away from the Sun is dark. If you look at Earth from the North Pole, the planet spins counterclockwise. As the Earth rotates, you see the Sun moving across the sky from east to west. We often say that the Sun is rising or setting. The Sun rises in the east and sets in the west. Actually, it is the Earths rotation that makes it appear that way. The Moon and the stars at night also seem to rise in the east and set in the west. Earths rotation is also responsible for this too. As Earth turns, the Moon and stars change position in the sky. "
Leap year is needed because Earth takes more than 365 days to orbit the Sun.,(A) true (B) false,A,"Earths revolution around the Sun takes 365.24 days. That is equal to one year. The Earth stays in orbit around the Sun because of the Suns gravity (Figure 24.12). Earths orbit is not a circle. It is somewhat elliptical. So as we travel around the Sun, sometimes we are a little farther away from the Sun. Sometimes we are closer to the Sun. Students sometimes think the slightly oval shape of our orbit causes Earths seasons. Thats not true! The seasons are due to the tilt of Earths axis, as discussed above. "
Earth tilts about 3 degrees on its axis.,(A) true (B) false,B,"Earths revolution around the Sun takes 365.24 days. That is equal to one year. The Earth stays in orbit around the Sun because of the Suns gravity (Figure 24.12). Earths orbit is not a circle. It is somewhat elliptical. So as we travel around the Sun, sometimes we are a little farther away from the Sun. Sometimes we are closer to the Sun. Students sometimes think the slightly oval shape of our orbit causes Earths seasons. Thats not true! The seasons are due to the tilt of Earths axis, as discussed above. "
Winter begins in the Southern Hemisphere on June 21.,(A) true (B) false,A,"Winter solstice for the Northern Hemisphere happens on December 21 or 22. The tilt of Earths axis points away from the Sun (Figure 1.3). Light from the Sun is spread out over a larger area, so that area isnt heated as much. With fewer daylight hours in winter, there is also less time for the Sun to warm the area. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. "
Earth gets more gravitational pull from the Sun than the Moon because it is larger.,(A) true (B) false,B,"Just as Earth orbits the sun, the moon also orbits Earth. The moon is affected by Earths gravity more than it is by the gravity of the sun because the moon is much closer to Earth. The gravity between Earth and the moon pulls the moon toward Earth. At the same time, the moon has forward velocity that partly counters the force of Earths gravity. So the moon orbits Earth instead of falling down to the surface of the planet. The Figure 1.2 shows the forces involved in the moons orbital motion around Earth. In the diagram, v represents the forward velocity of the moon, and a represents the acceleration due to gravity between Earth and the moon. The line encircling Earth shows the moons actual orbit, which results from the combination of v and a. "
The longest day in the Northern Hemisphere occurs on June 21.,(A) true (B) false,A,"The North Pole is tilted towards the Sun and the Suns rays strike the Northern Hemisphere more directly in summer (Figure 1.2). At the summer solstice, June 21 or 22, the Suns rays hit the Earth most directly along the Tropic of Cancer (23.5o N); that is, the angle of incidence of the Suns rays there is zero (the angle of incidence is the deviation in the angle of an incoming ray from straight on). When it is summer solstice in the Northern Hemisphere, it is winter solstice in the Southern Hemisphere. "
The planets move in fixed paths around the Sun.,(A) true (B) false,A,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
The Earths mostly iron crust produces the magnetic field.,(A) true (B) false,B,Earth is surrounded by a magnetic field (Figure 1.1) that behaves as if the planet had a gigantic bar magnet inside of it. Earths magnetic field also has a north and south pole. The magnetic field arises from the convection of molten iron and nickel metals in Earths liquid outer core. 
To make one complete rotation takes Earth 365.24 days.,(A) true (B) false,B,"Earths revolution around the Sun takes 365.24 days. That is equal to one year. The Earth stays in orbit around the Sun because of the Suns gravity (Figure 24.12). Earths orbit is not a circle. It is somewhat elliptical. So as we travel around the Sun, sometimes we are a little farther away from the Sun. Sometimes we are closer to the Sun. Students sometimes think the slightly oval shape of our orbit causes Earths seasons. Thats not true! The seasons are due to the tilt of Earths axis, as discussed above. "
Planets closer to the sun that Earth have shorter years.,(A) true (B) false,A,"Copernicus, Galileo, and Kepler were all right: Earth and the other planets travel in an elliptical orbit around the Sun. The gravitational pull of the Sun keeps the planets in orbit. This ellipse is barely elliptical; its very close to being a circle. The closest Earth gets to the Sun each year is at perihelion (147 million km) on about January 3rd, and the furthest is at aphelion (152 million km) on July 4th. The shape of Earths orbit has nothing to do with Earths seasons. Earth and the other planets in the solar system make elliptical orbits around the Sun. For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year. Earth has one large moon, which orbits Earth once every 29.5 days, a period known as a month. Click image to the left or use the URL below. URL: "
The hemisphere that receives less direct rays of sunlight is cooler.,(A) true (B) false,A,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
all of the water on Earth,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,D,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
half of a sphere,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,C,"Earth is a sphere or, more correctly, an oblate spheroid, which is a sphere that is a bit squished down at the poles and bulges a bit at the Equator. To be more technical, the minor axis (the diameter through the poles) is smaller than the major axis (the diameter through the Equator). Half of the sphere is a hemisphere. North of the Equator is the northern hemisphere and south of the Equator is the southern hemisphere. Eastern and western hemispheres are also designated. What evidence is there that Earth is spherical? What evidence was there before spaceships and satellites? Try to design an experiment involving a ship and the ocean to show Earth is round. If you are standing on the shore and a ship is going out to sea, the ship gets smaller as it moves further away from you. The ships bottom also starts to disappear as the vessel goes around the arc of the planet (Figure 1.1). There are many other ways that early scientists and mariners knew that Earth was not flat. The Sun and the other planets of the solar system are also spherical. Larger satellites, those that have enough mass for their gravitational attraction to have made them round, are spherical as well. Earths actual shape is not spherical but an oblate spheroid. The planet bulges around the equator due to mass collecting in the middle due to rotational momentum. "
spinning motion around an axis,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,G,"Earths axis is an imaginary line passing through the North and South Poles. Earthsrotation is its spins on its axis. Rotation is what a top does around its spindle. As Earth spins on its axis, it also orbits around the Sun. This is called Earths revolution. These motions lead to the cycles we see. Day and night, seasons, and the tides are caused by Earths motions. "
all of the living organisms on Earth,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,B,There are more than 1 million species of plants and animals known to be currently alive on Earth (Figure 1.1) and many millions more that have not been discovered yet. The tremendous variety of creatures is due to the tremendous numbers of habitats that organisms have evolved to fill. 
imaginary line passing through the poles of a planet,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,A,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
all of the solid rock of Earth,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,E,"The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. "
movement in an orbit around a larger body,(A) axis (B) biosphere (C) hemisphere (D) hydrosphere (E) lithosphere (F) revolution (G) rotation,F,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
The outer planets of the solar system are giant balls of,(A) solid ice (B) dense rock (C) liquid water (D) swirling gas,D,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
"Without gravity, the moon would",(A) drop to Earths surface (B) start orbiting the sun (C) fly off into space (D) shrink in size,C,"There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface. So there is no running water and no atmosphere. This means that there is no erosion. Natural processes continually alter the Earths surface. Without these processes, our planets surface would be covered with meteorite craters just like the Moon. Many moons in our solar system have cratered surfaces. NASA scientists have discovered a large number of water molecules mixed in with lunar dirt. There is also surface water ice. Even though there is a very small amount of water, there is no atmosphere. Temperatures are extreme. So it comes as no surprise that there has not been evidence of life on the Moon. "
The strength of the force of gravity between two objects depends on their,(A) mass (B) speed (C) distance apart (D) two of the above,D,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
Which statement about Earths magnetic field is false?,(A) It extends into space (B) It is caused by gravity (C) It has north and south poles (D) It shields Earth from harmful radiation,B,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
Earths motions contribute to,(A) tides (B) seasons (C) day and night (D) all of the above,D,"Earths axis is an imaginary line passing through the North and South Poles. Earthsrotation is its spins on its axis. Rotation is what a top does around its spindle. As Earth spins on its axis, it also orbits around the Sun. This is called Earths revolution. These motions lead to the cycles we see. Day and night, seasons, and the tides are caused by Earths motions. "
The side of Earth facing away from the sun is always,(A) in the dark (B) experiencing winter (C) cooler than the other side (D) two of the above,A,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
Earth has seasons because,(A) it tilts on its axis (B) its orbit is elliptical (C) it rotates on its axis (D) its distance from the sun varies,A,"Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. Different areas also receive different amounts of sunlight in different seasons. What causes the seasons? The seasons are caused by the direction Earths axis is pointing relative to the Sun. The Earth revolves around the Sun once each year and spins on its axis of rotation once each day. This axis of rotation is tilted 23.5o relative to its plane of orbit around the Sun. The axis of rotation is pointed toward Polaris, the North Star. As the Earth orbits the Sun, the tilt of Earths axis stays lined up with the North Star. "
A total of six spaceships have landed on the moon.,(A) true (B) false,A,"On May 25, 1961, President John F. Kennedy challenged the U.S. Congress: I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him back safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. The Soviets were also trying to reach the Moon. Who would win? The answer came eight years after Kennedys challenge, on July 20, 1969. NASAs Apollo 11 mission put astronauts Neil Armstrong and Buzz Aldrin on the Moon, as shown in Figure 23.21. A total of five American missions put astronauts on the Moon. The last was Apollo 17. This mission landed on December 11, 1972. No other country has yet put a person on the Moon. Today, most space missions are done by "
The flat dark areas on the Moon are,(A) lavas (B) dried lake beds (C) dried ocean basins (D) seawater,A,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
There are no current plans for returning to the moon.,(A) true (B) false,A,"There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface. So there is no running water and no atmosphere. This means that there is no erosion. Natural processes continually alter the Earths surface. Without these processes, our planets surface would be covered with meteorite craters just like the Moon. Many moons in our solar system have cratered surfaces. NASA scientists have discovered a large number of water molecules mixed in with lunar dirt. There is also surface water ice. Even though there is a very small amount of water, there is no atmosphere. Temperatures are extreme. So it comes as no surprise that there has not been evidence of life on the Moon. "
What are the lighter areas on the Moon?,(A) maria (B) craters (C) lakes (D) mountain ranges,D,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
The moons gravity is about half as strong as Earths gravity.,(A) true (B) false,B,"The Moon is Earths only natural satellite. The Moon is about one-fourth the size of Earth, 3,476 kilometers in diameter. Gravity on the Moon is only one-sixth as strong as it is on Earth. If you weigh 120 pounds on Earth, you would only weigh 20 pounds on the Moon. You can jump six times as high on the Moon as you can on Earth. The Moon makes no light of its own. Like every other body in the solar system, it only reflects light from the Sun. The Moon rotates on its axis once for every orbit it makes around the Earth. What does this mean? This means that the same side of the Moon always faces Earth. The side of the Moon that always faces Earth is called the near side. The side of the Moon that always faces away from Earth is called the far side (Figure 24.13). All people for all time have only seen the Moons near side. The far side has only been seen by spacecraft. The Moon has no atmosphere. With no atmosphere, the Moon is not protected from extreme temperatures. The average surface temperature during the day is approximately 107C (225F). Daytime temperatures can reach as high as 123C (253F). At night, the average temperature drops to -153C (-243F). The lowest temperatures measured are as low as -233C (-397F). "
What is the dominant feature on the lunar surface?,(A) volcanoes (B) craters (C) river basins (D) fault lines,B,"The landscape of the Moon - its surface features - is very different from Earth. The lunar landscape is covered by craters caused by asteroid impacts (Figure 24.14). The craters are bowl-shaped basins on the Moons surface. Because the Moon has no water, wind, or weather, the craters remain unchanged. The Moons coldest temperatures are found deep in the craters. The coldest craters are at the south pole on the Moons far side, where the Sun never shines. These temperatures are amongst the coldest in our entire solar system. "
The Moon has more extreme temperatures than Earth because it,(A) is closer to the Sun (B) rotates faster on its axis (C) doesnt have an atmosphere (D) has higher internal heat,C,"The Moon has no atmosphere. Since an atmosphere moderates temperature, the Moons average surface temperature during the day is approximately 225 F, but drops to -243 F at night. The coldest temperatures, around -397 F, occur in craters in the permanently shaded south polar basin. These are among the coldest temperatures recorded in the entire solar system. Earths landscape is extremely varied, with mountains, valleys, plains and hills. This landscape is always changing as plate tectonics builds new features and weathering and erosion destroys them. The landscape of the Moon is very different. With no plate tectonics, features are not built. With no atmosphere, features are not destroyed. Still, the Moon has a unique surface. Lunar surface features include the bowl-shaped craters that are caused by meteorite impacts (Figure 1.2). If Earth did not have plate tectonics or erosion, its surface would also be covered with meteorite craters. Even from Earth, the Moon has visible dark areas and light areas. The dark areas are called maria, which means seas because thats what the ancients thought they were. In fact, the maria are not water but solid, flat areas of basaltic lava. From about 3.0 to 3.5 billion years ago the Moon was continually bombarded by meteorites. Some of these meteorites were so large that they broke through the Moons newly formed surface. Then, magma flowed out and filled the craters. Scientists estimate this meteorite-caused volcanic activity on the Moon ceased about 1.2 billion years ago, but most occurred long before that. The lighter parts of the Moon are called terrae or highlands (Figure 1.3). The terrae are higher than the maria and A crater on the surface of the Moon. include several high mountain ranges. The terrae are the light silicate minerals that precipitated out of the ancient magma ocean and formed the early lunar crust. There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface, but water in the form of ice has been found in the extremely cold craters and bound up in the lunar soil. Despite the possible presence of water, the lack of an atmosphere and the extreme temperatures make it no surprise to scientists that the Moon has absolutely no evidence of life. Life from Earth has visited the Moon and there are footprints of astronauts on the lunar surface. With no wind, rain, or living thing to disturb them, these footprints will remain as long as the Moon exists. Only an impact with a meteorite could destroy them. "
It takes the moon the same amount of time to make one rotation as it does to make one revolution.,(A) true (B) false,A,"Earth rotates on its axis once every 24 hours. This is the length of an Earth day. Earth orbits the Sun once every 365.24 days. This is the length of an Earth year. Earth has one large moon. This satellite orbits Earth once every 29.5 days. This moon is covered with craters, and also has large plains of lava. The Moon came into being from material that flew into space after Earth and a giant asteroid collided. This moon is not a captured asteroid like other moons in the solar system. "
The far side of the moon has been seen only from spacecraft.,(A) true (B) false,A,"We all know what the Moon looks like. Its always looked the same during our lifetime. In fact, the Moon has looked the same to every person who has looked up at it for all time. Even the dinosaurs and trilobites, should they have looked up at it, would have seen the same thing. This is not true of Earth. Natural processes continually alter the Earths surface. Without these processes, would Earths surface resemble the Moons? Even though we cant see it from Earth, the Moon has changed recently too. Astronauts footprints are now on the Moon. They will remain unchanged for thousands of years, because there is no wind, rain, or living thing to disturb them. Only a falling meteorite could destroy them. "
The interior structure of the Moon is,(A) exactly like Earths (B) higher in metal (C) different on the near and far sides (D) the same as Earths but with less core,D,"Like Earth, the Moon has a distinct crust, mantle, and core. What is known about the Moons interior was determined from the analysis of rock samples gathered by astronauts and from unmanned spacecraft sent to the Moon (Figure The Moons small core, 600 to 800 kilometers in diameter, is mostly iron with some sulfur and nickel. The mantle is composed of the minerals olivine and orthopyroxene. Analysis of Moon rocks indicates that there may also be high levels of iron and titanium in the lunar mantle. A close-up of the Moon, showing maria (the dark areas) and terrae (the light areas); maria covers around 16% of the Moons surface, mostly on the side of the Moon we see. LCROSS crashed into the Moon in May 2009. This QUEST video describes the mission. After watching, look up the mission to see what they found! Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Most lunar maria are on the far side of the moon.,(A) true (B) false,B,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
Natural processes continually alter the moons surface.,(A) true (B) false,B,"We all know what the Moon looks like. Its always looked the same during our lifetime. In fact, the Moon has looked the same to every person who has looked up at it for all time. Even the dinosaurs and trilobites, should they have looked up at it, would have seen the same thing. This is not true of Earth. Natural processes continually alter the Earths surface. Without these processes, would Earths surface resemble the Moons? Even though we cant see it from Earth, the Moon has changed recently too. Astronauts footprints are now on the Moon. They will remain unchanged for thousands of years, because there is no wind, rain, or living thing to disturb them. Only a falling meteorite could destroy them. "
Lunar highlands are made of light-colored rocks.,(A) true (B) false,A,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
There are rivers but no lakes on the moon.,(A) true (B) false,B,"There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface. So there is no running water and no atmosphere. This means that there is no erosion. Natural processes continually alter the Earths surface. Without these processes, our planets surface would be covered with meteorite craters just like the Moon. Many moons in our solar system have cratered surfaces. NASA scientists have discovered a large number of water molecules mixed in with lunar dirt. There is also surface water ice. Even though there is a very small amount of water, there is no atmosphere. Temperatures are extreme. So it comes as no surprise that there has not been evidence of life on the Moon. "
Astronauts brought moon rocks back to Earth.,(A) true (B) false,A,"On May 25, 1961, President John F. Kennedy challenged the U.S. Congress: I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him back safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. The Soviets were also trying to reach the Moon. Who would win? The answer came eight years after Kennedys challenge, on July 20, 1969. NASAs Apollo 11 mission put astronauts Neil Armstrong and Buzz Aldrin on the Moon, as shown in Figure 23.21. A total of five American missions put astronauts on the Moon. The last was Apollo 17. This mission landed on December 11, 1972. No other country has yet put a person on the Moon. Today, most space missions are done by "
The Moon is Earths only natural satellite.,(A) true (B) false,A,"The Moon is Earths only natural satellite, a body that moves around a larger body in space. The Moon orbits Earth for the same reason Earth orbits the Sun  gravity. The Moon is 3,476 km in diameter, about one-fourth the size of Earth. The satellite is also not as dense as the Earth; gravity on the Moon is only one-sixth as strong as it is on Earth. An astronaut can jump six times as high on the Moon as on Earth! The Moon makes one complete orbit around the Earth every 27.3 days. The Moon also rotates on its axis once every 27.3 days. Do you know what this means? The same side of the Moon always faces Earth, so that side of the Moon is what we always see in the night sky (Figure 1.1). The Moon makes no light of its own, but instead only reflects light from the Sun. (a) The near side of the Moon faces Earth continually. It has a thinner crust with many more maria (flat areas of basaltic rock). (b) The far side of the Moon has only been seen by spacecraft. It has a thicker crust and far fewer maria (flat areas of basaltic rock). "
Astronauts last visited the moon in,(A) 1962 (B) 1972 (C) 1982 (D) 1992,B,"On May 25, 1961, President John F. Kennedy challenged the U.S. Congress: I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him back safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. The Soviets were also trying to reach the Moon. Who would win? The answer came eight years after Kennedys challenge, on July 20, 1969. NASAs Apollo 11 mission put astronauts Neil Armstrong and Buzz Aldrin on the Moon, as shown in Figure 23.21. A total of five American missions put astronauts on the Moon. The last was Apollo 17. This mission landed on December 11, 1972. No other country has yet put a person on the Moon. Today, most space missions are done by "
Most of the maria are on the Moons near side.,(A) true (B) false,A,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
The moons size is,(A) [U+215B] the size of Earth (B) 14 the size of Earth (C) 12 the size of Earth (D) 43 the size of Earth,B,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
The surface of the moon always looks the same because the moon has no,(A) gravity (B) weather (C) running water (D) two of the above,D,"We all know what the Moon looks like. Its always looked the same during our lifetime. In fact, the Moon has looked the same to every person who has looked up at it for all time. Even the dinosaurs and trilobites, should they have looked up at it, would have seen the same thing. This is not true of Earth. Natural processes continually alter the Earths surface. Without these processes, would Earths surface resemble the Moons? Even though we cant see it from Earth, the Moon has changed recently too. Astronauts footprints are now on the Moon. They will remain unchanged for thousands of years, because there is no wind, rain, or living thing to disturb them. Only a falling meteorite could destroy them. "
The lunar crust is thicker on the far side than on the near side.,(A) true (B) false,A,"Like Earth, the Moon has a distinct crust, mantle, and core. The crust is composed of igneous rock. This rock is rich in the elements oxygen, silicon, magnesium, and aluminum. On the near side, the Moons crust is about 60 kilometers thick. On the far side, the crust is about 100 kilometers thick. The mantle is made of rock like Earths mantle. The Moon has a small metallic core, perhaps 600 to 800 kilometers in diameter. The composition of the core is probably mostly iron with some sulfur and nickel. We learned this both from the rock samples gathered by astronauts and from spacecraft sent to the Moon. "
The coldest temperatures on the moon are found,(A) deep in craters (B) at the north pole (C) where the sun never shines (D) two of the above,D,"The landscape of the Moon - its surface features - is very different from Earth. The lunar landscape is covered by craters caused by asteroid impacts (Figure 24.14). The craters are bowl-shaped basins on the Moons surface. Because the Moon has no water, wind, or weather, the craters remain unchanged. The Moons coldest temperatures are found deep in the craters. The coldest craters are at the south pole on the Moons far side, where the Sun never shines. These temperatures are amongst the coldest in our entire solar system. "
The Moon rotates on its axis once for every orbit it makes around the Sun.,(A) true (B) false,B,"The Moon is Earths only natural satellite, a body that moves around a larger body in space. The Moon orbits Earth for the same reason Earth orbits the Sun  gravity. The Moon is 3,476 km in diameter, about one-fourth the size of Earth. The satellite is also not as dense as the Earth; gravity on the Moon is only one-sixth as strong as it is on Earth. An astronaut can jump six times as high on the Moon as on Earth! The Moon makes one complete orbit around the Earth every 27.3 days. The Moon also rotates on its axis once every 27.3 days. Do you know what this means? The same side of the Moon always faces Earth, so that side of the Moon is what we always see in the night sky (Figure 1.1). The Moon makes no light of its own, but instead only reflects light from the Sun. (a) The near side of the Moon faces Earth continually. It has a thinner crust with many more maria (flat areas of basaltic rock). (b) The far side of the Moon has only been seen by spacecraft. It has a thicker crust and far fewer maria (flat areas of basaltic rock). "
You would weigh six times as much on the Moon as on Earth.,(A) true (B) false,B,"If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force. Mass and weight are closely related. However, the weight of an object can change if the force of gravity changes. On Earth, the force of gravity is the same everywhere. So how does the force of gravity change? It doesnt if you stay on Earth. What if we travel to another planet or moon in our solar system? Look at the photo of astronaut Edwin E. Aldrin Jr. taken by fellow astronaut Neil Armstrong in the Figure ??. They were the first humans to walk on the moon. An astronaut weighs less on the moon than he would on Earth. This is because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. If the astronaut weighed 175 pounds on Earth, he would have weighed only 29 pounds on the moon. If his mass on Earth was 80 kg, what would his mass have been on the moon? [Figure 3] "
Which statement about lunar maria is false?,(A) They are still forming (B) They look dark from Earth (C) They formed billions of years ago (D) They formed when magma filled craters,A,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
Which of the following would you not expect to find on the moon?,(A) ice (B) dirt (C) bacteria (D) water molecules,C,"There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface. So there is no running water and no atmosphere. This means that there is no erosion. Natural processes continually alter the Earths surface. Without these processes, our planets surface would be covered with meteorite craters just like the Moon. Many moons in our solar system have cratered surfaces. NASA scientists have discovered a large number of water molecules mixed in with lunar dirt. There is also surface water ice. Even though there is a very small amount of water, there is no atmosphere. Temperatures are extreme. So it comes as no surprise that there has not been evidence of life on the Moon. "
You could find oxygen on the moon if you analyzed the,(A) core (B) crust (C) atmosphere (D) none of the above,B,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
surface features of a moon or planet,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,E,"The landscape of the Moon - its surface features - is very different from Earth. The lunar landscape is covered by craters caused by asteroid impacts (Figure 24.14). The craters are bowl-shaped basins on the Moons surface. Because the Moon has no water, wind, or weather, the craters remain unchanged. The Moons coldest temperatures are found deep in the craters. The coldest craters are at the south pole on the Moons far side, where the Sun never shines. These temperatures are amongst the coldest in our entire solar system. "
highlands on the moon,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,C,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
cause of lunar craters,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,G,"The landscape of the Moon - its surface features - is very different from Earth. The lunar landscape is covered by craters caused by asteroid impacts (Figure 24.14). The craters are bowl-shaped basins on the Moons surface. Because the Moon has no water, wind, or weather, the craters remain unchanged. The Moons coldest temperatures are found deep in the craters. The coldest craters are at the south pole on the Moons far side, where the Sun never shines. These temperatures are amongst the coldest in our entire solar system. "
related to the moon,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,A,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
flat areas of lava on the moons surface,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,B,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
bowl-shaped basin on the moons surface,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,D,"The landscape of the Moon - its surface features - is very different from Earth. The lunar landscape is covered by craters caused by asteroid impacts (Figure 24.14). The craters are bowl-shaped basins on the Moons surface. Because the Moon has no water, wind, or weather, the craters remain unchanged. The Moons coldest temperatures are found deep in the craters. The coldest craters are at the south pole on the Moons far side, where the Sun never shines. These temperatures are amongst the coldest in our entire solar system. "
cause of lunar maria,(A) lunar (B) maria (C) terrae (D) crater (E) landscape (F) meteorites (G) asteroids,F,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
The layer that shows beyond the Moon in a solar eclipse is the,(A) corona (B) photosphere (C) radiative zone (D) prominence zone,A,The three outer layers of the Sun are its atmosphere. 
Which layer of the Sun contains slow moving photons?,(A) corona (B) core (C) radiative zone (D) convection zone,C,"The radiative zone is the next layer out. It has a temperature of about 4 million degrees C. Energy from the core travels through the radiative zone. The rate the energy travels is extremely slow. Light particles, called photons, can only travel a few millimeters before they hit another particle. The particles are absorbed and then released again. It may take 50 million years for a photon to travel all the way through the radiative zone. "
Most atoms in the Sun exist as,(A) photons (B) plasma (C) light (D) silicate minerals,B,"The Sun is made almost entirely of the elements hydrogen and helium. The Sun has no solid material. Most atoms in the Sun exist as plasma. Plasma is superheated gas with an electrical charge. Because the Sun is made of gases, it does not have a defined outer boundary. Like Earth, the Sun has an internal structure. The inner three layers make up what we would actually call the Sun. "
The energy that powers the Sun comes from,(A) hydrogen fusing into helium (B) radioactivity (C) helium fusing into heavier elements (D) nuclear fission,A,"Energy from the Sun comes from the lightest element, hydrogen, fusing together to create the second lightest element, helium. Nuclear fusion on the Sun releases tremendous amounts of solar energy. The energy travels to the Earth, mostly as visible light. The light carries the energy through the empty space between the Sun and the Earth as radiation. "
Cool areas where the magnetic field disrupts the surface are,(A) solar flares (B) solar prominences (C) solar winds (D) sunspots,D,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
The sun makes up over 99 percent of the mass of the solar system.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
The suns core is made of solid rock.,(A) true (B) false,B,"The core is the Suns innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer layers of the Sun. Energy from the Suns core powers most of the solar system. "
The sun has no atmosphere.,(A) true (B) false,B,The three outer layers of the Sun are its atmosphere. 
The Suns core is molten metal.,(A) true (B) false,B,"The core is the Suns innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer layers of the Sun. Energy from the Suns core powers most of the solar system. "
The suns energy comes from reactions in which hydrogen changes to helium.,(A) true (B) false,A,"Energy from the Sun comes from the lightest element, hydrogen, fusing together to create the second lightest element, helium. Nuclear fusion on the Sun releases tremendous amounts of solar energy. The energy travels to the Earth, mostly as visible light. The light carries the energy through the empty space between the Sun and the Earth as radiation. "
A solar flare can knock out power grids on Earth.,(A) true (B) false,A,"A loop of the Suns magnetic field may break. This creates solar flares. Solar flares are violent explosions that release huge amounts of energy (Figure 24.19). The streams of high energy particles they emit make up the solar wind. Solar wind is dangerous to spacecraft and astronauts. Solar flares can even cause damage on Earth. They have knocked out entire power grids and can disturb radio, satellite, and cell phone communications. "
Energy travels through the radiative zone of the sun at the speed of light.,(A) true (B) false,B,"The radiative zone is the next layer out. It has a temperature of about 4 million degrees C. Energy from the core travels through the radiative zone. The rate the energy travels is extremely slow. Light particles, called photons, can only travel a few millimeters before they hit another particle. The particles are absorbed and then released again. It may take 50 million years for a photon to travel all the way through the radiative zone. "
The part of the sun that we see shining is the convective zone.,(A) true (B) false,B,"The convection zone surrounds the radiative zone. In the convection zone, hot material from near the Suns center rises. This material cools at the surface, and then plunges back downward. The material then receives more heat from the radiative zone. "
The Sun makes up 99.8% of the mass of the solar system.,(A) true (B) false,A,"Since the time of Copernicus, Kepler, and Galileo, we have learned a lot more about our solar system. Astronomers have discovered two more planets (Uranus and Neptune), five dwarf planets (Ceres, Pluto, Makemake, Haumea, and Eris), more than 150 moons, and many, many asteroids and other small objects. Although the Sun is just an average star compared to other stars, it is by far the largest object in the solar system. The Sun is more than 500 times the mass of everything else in the solar system combined! Table 1.1 gives data on the sizes of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter Object Mass (Relative to Earth) Mars Jupiter Saturn Uranus Neptune 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass 17.2 Earths mass Diameter of Planet (Relative to Earth) 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter 3.81 Earths diameter "
The corona is the coolest layer of the sun.,(A) true (B) false,B,"The corona is the outermost part of the Suns atmosphere. It is the Suns halo, or crown. With a temperature of 1 to 3 million K, the corona is much hotter than the photosphere. The corona extends millions of kilometers into space. Sometime you should try to see a total solar eclipse. If you do you will see the Suns corona shining out into space. "
The Sun does not have a defined outer boundary.,(A) true (B) false,A,The three outer layers of the Sun are its atmosphere. 
Plasma is a solid.,(A) true (B) false,B,"Youre probably less familiar with plasmas than with solids, liquids, and gases. Yet, most of the universe consists of plasma. Plasma is a state of matter that resembles a gas but has certain properties that a gas does not have. Like a gas, plasma lacks a fixed volume and shape. Unlike a gas, plasma can conduct electricity and respond to magnetism. Thats because plasma contains charged particles called ions. This gives plasma other interesting properties. For example, it glows with light. Where can you find plasmas? Two examples are shown in Figure 4.7. The sun and other stars consist of plasma. Plasmas are also found naturally in lightning and the polar auroras (northern and southern lights). Artificial plasmas are found in fluorescent lights, plasma TV screens, and plasma balls like the one that opened this chapter. You can learn more about plasmas at this URL:  (2:58). MEDIA Click image to the left or use the URL below. URL: "
Sunspots occur because of magnetic activity of the sun.,(A) true (B) false,A,"The most noticeable magnetic activity of the Sun is the appearance of sunspots. Sunspots are cooler, darker areas on the Suns surface (Figure 24.18). Sunspots occur in an 11 year cycle. The number of sunspots begins at a minimum. The number gradually increases to the maximum. Then the number returns to a minimum again. Sunspots form because loops of the Suns magnetic field break through the surface. Sunspots usually occur in pairs. The loop breaks through the surface where it comes out of the Sun. It breaks through again where it goes back into the Sun. Sunspots disrupt the transfer of heat from the Suns lower layers. "
Solar wind is dangerous to spacecraft and astronauts.,(A) true (B) false,A,"A loop of the Suns magnetic field may break. This creates solar flares. Solar flares are violent explosions that release huge amounts of energy (Figure 24.19). The streams of high energy particles they emit make up the solar wind. Solar wind is dangerous to spacecraft and astronauts. Solar flares can even cause damage on Earth. They have knocked out entire power grids and can disturb radio, satellite, and cell phone communications. "
Solar prominences are mountains on the suns surface.,(A) true (B) false,B,"Another highly visible feature on the Sun are solar prominences. If plasma flows along a loop of the Suns magnetic field from sunspot to sunspot, it forms a glowing arch that reaches thousands of kilometers into the Suns atmosphere. Prominences can last lengths of time ranging from a day to several months. Prominences are also visible during a total solar eclipse. Most of the imagery comes from SDOs AIA instrument; different colors represent different temperatures, a common technique for observing solar features. SDO sees the entire disk of the Sun in extremely high spatial and temporal resolution, allowing scientists to zoom in on notable events such as flares, waves, and sunspots. "
Most of the atoms of the sun exist as,(A) solids (B) liquids (C) gases (D) plasma,D,"The Sun is made almost entirely of the elements hydrogen and helium. The Sun has no solid material. Most atoms in the Sun exist as plasma. Plasma is superheated gas with an electrical charge. Because the Sun is made of gases, it does not have a defined outer boundary. Like Earth, the Sun has an internal structure. The inner three layers make up what we would actually call the Sun. "
Most of the solar system is powered by energy that originates in the suns,(A) core (B) corona (C) photosphere (D) chromosphere,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
Energy travels through the radiative zone of the sun as particles called,(A) photons (B) protons (C) plasmas (D) none of the above,A,"The radiative zone is the next layer out. It has a temperature of about 4 million degrees C. Energy from the core travels through the radiative zone. The rate the energy travels is extremely slow. Light particles, called photons, can only travel a few millimeters before they hit another particle. The particles are absorbed and then released again. It may take 50 million years for a photon to travel all the way through the radiative zone. "
Which of the following statements about sunspots is false?,(A) They usually occur in pairs (B) They repeat in 11-year cycles (C) They disrupt heat transfer in the sun (D) They are storms on the suns surface,D,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
Solar flares occur when,(A) there is a break in a loop of the suns magnetic field (B) solar wind causes fires to flare up on the suns surface (C) nuclear reactions take place in the suns atmosphere (D) matter inside the sun changes to the plasma state,A,"A loop of the Suns magnetic field may break. This creates solar flares. Solar flares are violent explosions that release huge amounts of energy (Figure 24.19). The streams of high energy particles they emit make up the solar wind. Solar wind is dangerous to spacecraft and astronauts. Solar flares can even cause damage on Earth. They have knocked out entire power grids and can disturb radio, satellite, and cell phone communications. "
The hottest part of the sun is the,(A) convection zone (B) radiative zone (C) corona (D) core,D,"The photosphere is the visible surface of the Sun (Figure 24.17). Its the part that we see shining. Surprisingly, the photosphere is also one of the coolest layers of the Sun. It is only about 6000 degrees C. "
Power grids and communication systems on Earth may be disturbed by a,(A) sunspot (B) solar flare (C) solar corona (D) solar fusion reaction,B,"There are other types of interruptions of the Suns magnetic energy. If a loop of the Suns magnetic field snaps and breaks, it creates solar flares, which are violent explosions that release huge amounts of energy (Figure 1.2). A strong solar flare can turn into a coronal mass ejection. A solar flare or coronal mass ejection releases streams of highly energetic particles that make up the solar wind. The solar wind can be dangerous to spacecraft and astronauts because it sends out large amounts of radiation that can harm the human body. Solar flares have knocked out entire power grids and disturbed radio, satellite, and cell phone communications. (a) Sunspots. (b) A close-up of a sunspot taken in ultraviolet light. "
"relatively cool, dark area on the suns surface",(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,G,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
superheated gas with an electrical charge,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,D,"Another example of static discharge, but on a much larger scale, is lightning. You can see how it occurs in the following diagram (Figure 1.1). During a rainstorm, clouds develop regions of positive and negative charge due to the movement of air molecules, water drops, and ice particles. The negative charges are concentrated at the base of the clouds, and the positive charges are concentrated at the top. The negative charges repel electrons on the ground beneath them, so the ground below the clouds becomes positively charged. At first, the atmosphere prevents electrons from flowing away from areas of negative charge and toward areas of positive charge. As more charges build up, however, the air between the oppositely charged areas also becomes charged. When this happens, static electricity is discharged as bolts of lightning. "
layer of the sun that surrounds the radiative zone,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,E,"The convection zone surrounds the radiative zone. In the convection zone, hot material from near the Suns center rises. This material cools at the surface, and then plunges back downward. The material then receives more heat from the radiative zone. "
visible layer of the suns atmosphere,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,C,The three outer layers of the Sun are its atmosphere. 
layer of the suns atmosphere that glows red,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,A,The three outer layers of the Sun are its atmosphere. 
layer of the sun nearest the core,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,F,The three outer layers of the Sun are its atmosphere. 
hottest layer of the suns atmosphere,(A) chromosphere (B) corona (C) photosphere (D) plasma (E) convection zone (F) radiative zone (G) sunspot,B,The three outer layers of the Sun are its atmosphere. 
phase of the moon in which half of the side facing Earth is lit,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,B,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
What are the two distinct parts of Earths shadow during a solar eclipse?,(A) light and dark (B) panera and umbrella (C) umbra and penumbra (D) inner and outer,C,"When a new moon passes directly between the Earth and the Sun, it causes a solar eclipse (Figure 24.20). The Moon casts a shadow on the Earth and blocks our view of the Sun. This happens only all three are lined up and in the same plane. This plane is called the ecliptic. The ecliptic is the plane of Earths orbit around the Sun. The Moons shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moons shadow. It is where the light is only partially blocked. When the Moons shadow completely blocks the Sun, it is a total solar eclipse (Figure 24.21). If only part of the Sun is out of view, it is a partial solar eclipse. Solar eclipses are rare events. They usually only last a few minutes. That is because the Moons shadow only covers a very small area on Earth and Earth is turning very rapidly. Solar eclipses are amazing to experience. It appears like night only strange. Birds may sing as they do at dusk. Stars become visible in the sky and it gets colder outside. Unlike at night, the Sun is out. So during a solar eclipse, its easy to see the Suns corona and solar prominences. This NASA page will inform you on when solar eclipses are expected: http://eclipse.gsfc.nasa.gov/solar.html "
phase of the moon in which the entire side facing Earth is dark,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,G,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
"If the Moon is more than half lit, but the left side is dark, the phase is",(A) first quarter (B) waxing gibbous (C) waning gibbous (D) last quarter,B,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
event in which Earth casts a shadow on the moon,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,C,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
"When the full moon moves through Earths shadow, what occurs?",(A) solar eclipse (B) high tide (C) low tide (D) lunar eclipse,A,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
A quarter moon is,(A) halfway between a full moon and a new moon (B) two weeks after a full moon (C) when one quarter of the moon you see is lit (D) when one quarter of the moon you see is dark,A,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
inner part of the moons shadow during an eclipse,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,D,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
event in which the moon casts a shadow on Earth,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,E,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
What is the moon called when it is more than half lit?,(A) a harvest moon (B) a blue moon (C) a crescent moon (D) a gibbous moon,D,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
outer part of the moons shadow during an eclipse,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,F,"When a new moon passes directly between the Earth and the Sun, it causes a solar eclipse (Figure 24.20). The Moon casts a shadow on the Earth and blocks our view of the Sun. This happens only all three are lined up and in the same plane. This plane is called the ecliptic. The ecliptic is the plane of Earths orbit around the Sun. The Moons shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moons shadow. It is where the light is only partially blocked. When the Moons shadow completely blocks the Sun, it is a total solar eclipse (Figure 24.21). If only part of the Sun is out of view, it is a partial solar eclipse. Solar eclipses are rare events. They usually only last a few minutes. That is because the Moons shadow only covers a very small area on Earth and Earth is turning very rapidly. Solar eclipses are amazing to experience. It appears like night only strange. Birds may sing as they do at dusk. Stars become visible in the sky and it gets colder outside. Unlike at night, the Sun is out. So during a solar eclipse, its easy to see the Suns corona and solar prominences. This NASA page will inform you on when solar eclipses are expected: http://eclipse.gsfc.nasa.gov/solar.html "
phase of the moon in which the entire side facing Earth is lit,(A) full moon (B) quarter moon (C) lunar eclipse (D) umbra (E) solar eclipse (F) penumbra (G) new moon,A,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
A lunar eclipse generally lasts between 5-10 minutes.,(A) true (B) false,B,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
Birds may become confused during a solar eclipse and think that it is nighttime.,(A) true (B) false,A,"When a new moon passes directly between the Earth and the Sun, it causes a solar eclipse (Figure 24.20). The Moon casts a shadow on the Earth and blocks our view of the Sun. This happens only all three are lined up and in the same plane. This plane is called the ecliptic. The ecliptic is the plane of Earths orbit around the Sun. The Moons shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moons shadow. It is where the light is only partially blocked. When the Moons shadow completely blocks the Sun, it is a total solar eclipse (Figure 24.21). If only part of the Sun is out of view, it is a partial solar eclipse. Solar eclipses are rare events. They usually only last a few minutes. That is because the Moons shadow only covers a very small area on Earth and Earth is turning very rapidly. Solar eclipses are amazing to experience. It appears like night only strange. Birds may sing as they do at dusk. Stars become visible in the sky and it gets colder outside. Unlike at night, the Sun is out. So during a solar eclipse, its easy to see the Suns corona and solar prominences. This NASA page will inform you on when solar eclipses are expected: http://eclipse.gsfc.nasa.gov/solar.html "
During a total lunar eclipse the moon is entirely dark.,(A) true (B) false,B,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
A solar eclipse is seen on all of the Earth that is having daytime.,(A) true (B) false,B,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
The time between two full moon phases is 29.5 days.,(A) true (B) false,A,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
The cone-shaped part of the moons shadow is the penumbra.,(A) true (B) false,B,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
Light is only partly blocked in the umbra part of a shadow.,(A) true (B) false,B,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
Solar eclipses are rare events.,(A) true (B) false,A,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
"During a partial lunar eclipse, only part of the moon enters Earths umbra.",(A) true (B) false,A,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
A total lunar eclipse occurs once every month.,(A) true (B) false,B,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
The full moon phase occurs when the moon is on the opposite side of Earth from the sun.,(A) true (B) false,A,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
A crescent phase follows the first quarter phase of the moon.,(A) true (B) false,B,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
"If the new moon occurs on the 1st of the month, the full moon will occur on the 28th of the month.",(A) true (B) false,B,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
"When a lunar eclipse occurs, the sun cannot be seen from Earth.",(A) true (B) false,B,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
"When a solar eclipse occurs, the moon cannot be seen from Earth.",(A) true (B) false,B,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
"Interactions between the sun, moon, and Earth include",(A) lunar and solar eclipses (B) phases of the moon (C) Earths tides (D) all of the above,D,"Earth and Moon orbit each other. This Earth-Moon system orbits the Sun in a regular path (Figure 24.4). Gravity is the force of attraction between all objects. Gravity keeps the Earth and Moon in their orbits. Earths gravity pulls the Moon toward Earths center. Without gravity, the Moon would continue moving in a straight line off into space. All objects in the universe have a gravitational attraction to each other (Figure 24.5). The strength of the force of gravity depends on two things. They are the mass of the objects and the distance between them. The greater the objects mass, the greater the force of attraction. As the distance between the objects increases, the force of attraction decreases. "
The ecliptic is the,(A) plane in which Earth orbits the sun (B) distance between the moon and Earth (C) period during which an eclipse occurs (D) difference in size between the umbra and penumbra,A,"Copernicus, Galileo, and Kepler were all right: Earth and the other planets travel in an elliptical orbit around the Sun. The gravitational pull of the Sun keeps the planets in orbit. This ellipse is barely elliptical; its very close to being a circle. The closest Earth gets to the Sun each year is at perihelion (147 million km) on about January 3rd, and the furthest is at aphelion (152 million km) on July 4th. The shape of Earths orbit has nothing to do with Earths seasons. Earth and the other planets in the solar system make elliptical orbits around the Sun. For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year. Earth has one large moon, which orbits Earth once every 29.5 days, a period known as a month. Click image to the left or use the URL below. URL: "
A total solar eclipse occurs when,(A) Earths umbra falls on the moon (B) Earths shadow completely blocks the moon (C) the moons shadow completely blocks the sun (D) none of the above,C,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
A solar eclipse usually lasts for,(A) a few minutes (B) at least an hour (C) a few hours (D) a day or more,A,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
The moon passes through all of its phases about once every,(A) week (B) 2 weeks (C) month (D) 2 months,C,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
How much time goes by between the new moon and first quarter moon phases?,(A) 1 week (B) 2 weeks (C) 3 weeks (D) 4 weeks,A,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
Which phase of the moon occurs next after the full moon phase?,(A) third quarter moon (B) crescent moon (C) gibbous moon (D) new moon,C,"The Moon does not produce any light of its own. It only reflects light from the Sun. As the Moon moves around the Earth, we see different parts of the Moon lit up by the Sun. This causes the phases of the Moon. As the Moon revolves around Earth, it changes from fully lit to completely dark and back again. A full moon occurs when the whole side facing Earth is lit. This happens when Earth is between the Moon and the Sun. About one week later, the Moon enters the quarter-moon phase. Only half of the Moons lit surface is visible from Earth, so it appears as a half circle. When the Moon moves between Earth and the Sun, the side facing Earth is completely dark. This is called the new moon phase. Sometimes you can just barely make out the outline of the new moon in the sky. This is because some sunlight reflects off the Earth and hits the Moon. Before and after the quarter-moon phases are the gibbous and crescent phases. During the crescent moon phase, the Moon is less than half lit. It is seen as only a sliver or crescent shape. During the gibbous moon phase, the Moon is more than half lit. It is not full. The Moon undergoes a complete cycle of phases about every 29.5 days. "
collection of many small objects beyond the orbit of Neptune,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,B,"Neptune has faint rings of ice and dust that may change or disappear in fairly short time frames. Neptune has 13 known moons. Triton, shown in Figure 1.3, is the only one of them that has enough mass to be spherical in shape. Triton orbits in the direction opposite to the orbit of Neptune. Scientists think Triton did not form around Neptune, but instead was captured by Neptunes gravity as it passed by. This image of Triton, Neptunes largest moon, was taken by Voyager 2 in 1989. "
The planets appear to move,(A) in the same direction as the stars (B) some with and some opposite the stars (C) in a circular motion (D) sometimes with and sometimes opposite the stars,D,"To an observer, Earth appears to be the center of the universe. That is what the ancient Greeks believed. This view is called the geocentric model, or ""Earth-centered"" model, of the universe. In the geocentric model, the sky, or heavens, are a set of spheres layered on top of one another. Each object in the sky is attached to a sphere and moves around Earth as that sphere rotates. From Earth outward, these spheres contain the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. An outer sphere holds all the stars. Since the planets appear to move much faster than the stars, the Greeks placed them closer to Earth. The geocentric model explained why all the stars appear to rotate around Earth once per day. The model also explained why the planets move differently from the stars and from each other. One problem with the geocentric model is that some planets seem to move backwards (in retrograde) instead of in their usual forward motion around Earth. Around 150 A.D. the astronomer Ptolemy resolved this problem by using a system of circles to describe the motion of planets (Figure 1.1). In Ptolemys system, a planet moves in a small circle, called an epicycle. This circle moves around Earth in a larger circle, called a deferent. Ptolemys version of the geocentric model worked so well that it remained the accepted model of the universe for more than a thousand years. "
distance from Earth to the sun,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,A,"Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km, or 93 million miles. Table 1.2 shows the distances to the planets (the average radius of orbits) in AU. The table also shows how long it takes each planet to spin on its axis (the length of a day) and how long it takes each planet to complete an orbit (the length of a year); in particular, notice how slowly Venus rotates relative to Earth. Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year (In Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 Click image to the left or use the URL below. URL: "
The model that put the Sun at the center of the universe was proposed by,(A) Aristotle (B) Galileo (C) Copernicus (D) Ptolemy,C,"About 1,500 years after Ptolemy, Copernicus proposed a startling idea. He suggested that the Sun is at the center of the universe. Copernicus developed his model because it better explained the motions of the planets. Figure 25.2 shows both the Earth-centered and Sun-centered models. Copernicus did not publish his new model until his death. He knew that it was heresy to say that Earth was not the center of the universe. It wasnt until Galileo developed his telescope that people would take the Copernican "
star and the planets that orbit it,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,E,"The Sun and all the objects that are held by the Suns gravity are known as the solar system. These objects all revolve around the Sun. The ancient Greeks recognized five planets. These lights in the night sky changed their position against the background of stars. They appeared to wander. In fact, the word planet comes from a Greek word meaning wanderer. These objects were thought to be important, so they named them after gods from their mythology. The names for the planets Mercury, Venus, Mars, Jupiter, and Saturn came from the names of gods and a goddess. "
Extrasolar planets are found by,(A) the wobble of a star on its axis (B) the periodic dimming in of a star (C) being visible through a telescope (D) the excess gravity of a star,B,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
All of the planets in the solar system,(A) lie in the same plane (B) are made mostly of rocks and metals (C) rotate in the same direction (D) all of these,A,"The Sun and all the objects that are held by the Suns gravity are known as the solar system. These objects all revolve around the Sun. The ancient Greeks recognized five planets. These lights in the night sky changed their position against the background of stars. They appeared to wander. In fact, the word planet comes from a Greek word meaning wanderer. These objects were thought to be important, so they named them after gods from their mythology. The names for the planets Mercury, Venus, Mars, Jupiter, and Saturn came from the names of gods and a goddess. "
collection of many small objects between the orbits of Mars and Jupiter,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,F,"Hundreds of thousands of asteroids have been discovered in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month. The majority of the asteroids are found in between the orbits of Mars In 1991, Asteroid 951 Gaspra was the first asteroid photographed at close range. Gaspra is a medium-sized asteroid, mea- suring about 19 by 12 by 11 km (12 by 7.5 by 7 mi). and Jupiter, in a region called the asteroid belt, as shown in Figure 1.2. Although there are many thousands of asteroids in the asteroid belt, their total mass adds up to only about 4% of Earths Moon. The white dots in the figure are asteroids in the main asteroid belt. Other groups of asteroids closer to Jupiter are called the Hildas (orange), the Trojans (green), and the Greeks (also green). Scientists think that the bodies in the asteroid belt formed during the formation of the solar system. The asteroids might have come together to make a single planet, but they were pulled apart by the intense gravity of Jupiter. "
planet that orbits a star other than the sun,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,G,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
The force of gravity between objects depends on their mass and __________,(A) acceleration (B) distance apart (C) gravitational potential energy (D) density,B,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity. For example, because Earth is so massive, it attracts you and your desk more strongly than you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. This is illustrated in Figure You can apply these relationships among mass, distance, and gravity by designing your own roller coaster at this URL:  . "
planet such as Pluto,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,D,"For decades Pluto was a planet. But even then, scientists knew it was an unusual planet. The other outer planets are all gas giants. Pluto is small, icy and rocky. With a diameter of about 2400 kilometers, it has only about 1/5 the mass of Earths Moon. The other planets orbit in a plane. Plutos orbit is tilted. The shape of the orbit is like a long, narrow ellipse. Plutos orbit is so elliptical that sometimes it is inside the orbit of Neptune. Plutos orbit is in the Kuiper belt. We have discovered more than 200 million Kuiper belt objects. Pluto has 3 moons of its own. The largest, Charon, is big. Some scientists think that Pluto-Charon system is a double dwarf planet (Figure 25.37). Two smaller moons, Nix and Hydra, were discovered in 2005. "
giant cloud of gas and dust,(A) astronomical unit (B) Kuiper belt (C) nebula (D) dwarf planet (E) solar system (F) asteroid belt (G) exoplanet,C,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
If you know a planets orbit you can determine its approximate distance from the Sun.,(A) true (B) false,A,"Figure 1.1 shows the relative sizes of the orbits of the planets, asteroid belt, and Kuiper belt. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. The orbits of the planets are not circular but slightly elliptical, with the Sun located at one of the foci (see opening image). While studying the solar system, Johannes Kepler discovered the relationship between the time it takes a planet to make one complete orbit around the Sun, its ""orbital period,"" and the distance from the Sun to the planet. If the orbital period of a planet is known, then it is possible to determine the planets distance from the Sun. This is how astronomers without modern telescopes could determine the distances to other planets within the solar system. How old are you on Earth? How old would you be if you lived on Jupiter? How many days is it until your birthday on Earth? How many days until your birthday if you lived on Saturn? Click image to the left or use the URL below. URL:  The relative sizes of the orbits of planets in the solar system. The inner solar sys- tem and asteroid belt is on the upper left. The upper right shows the outer planets and the Kuiper belt. "
"The planets in order from the Sun are Mars, Venus, Earth, Mercury, Saturn, Uranus, Jupiter and Neptune.",(A) true (B) false,B,"Today we know that we have eight planets, five dwarf planets, over 165 moons, and many, many asteroids and other small objects in our solar system. We also know that the Sun is not the center of the universe. But it is the center of the solar system. Figure 25.3 shows our solar system. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Table 25.1 gives some data on the mass and diameter of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth Mars Jupiter Saturn Uranus 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter Neptune 17.2 Earths mass "
The orbits of the planets are circular.,(A) true (B) false,B,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
One astronomical unit is the distance from Earth to Sun.,(A) true (B) false,A,"Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km, or 93 million miles. Table 1.2 shows the distances to the planets (the average radius of orbits) in AU. The table also shows how long it takes each planet to spin on its axis (the length of a day) and how long it takes each planet to complete an orbit (the length of a year); in particular, notice how slowly Venus rotates relative to Earth. Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year (In Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 Click image to the left or use the URL below. URL: "
All of the planets in the solar system rotate in the same direction.,(A) true (B) false,B,"Most of the planets in the solar system rotate on their axes in the same direction that they move around the Sun. Uranus, though, is tilted on its side, so its axis is almost parallel to its orbit. In other words, it rotates like a top that was turned so that it was spinning parallel to the floor. Scientists think that Uranus was probably knocked over by a collision with another planet-sized object billions of years ago. "
The planets in our solar system were named for Greek gods and goddesses.,(A) true (B) false,A,"The Sun and all the objects that are held by the Suns gravity are known as the solar system. These objects all revolve around the Sun. The ancient Greeks recognized five planets. These lights in the night sky changed their position against the background of stars. They appeared to wander. In fact, the word planet comes from a Greek word meaning wanderer. These objects were thought to be important, so they named them after gods from their mythology. The names for the planets Mercury, Venus, Mars, Jupiter, and Saturn came from the names of gods and a goddess. "
We now know that the sun is the center of the universe.,(A) true (B) false,B,"About 1,500 years after Ptolemy, Copernicus proposed a startling idea. He suggested that the Sun is at the center of the universe. Copernicus developed his model because it better explained the motions of the planets. Figure 25.2 shows both the Earth-centered and Sun-centered models. Copernicus did not publish his new model until his death. He knew that it was heresy to say that Earth was not the center of the universe. It wasnt until Galileo developed his telescope that people would take the Copernican "
Scientists think that our solar system formed from an asteroid belt.,(A) true (B) false,B,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
The planets formed when pieces of matter collided and clumped together.,(A) true (B) false,A,Material at a similar distances from the Sun collided together to form each of the planets. Earth grew from material in its part of space. Moons origin was completely different from Earths. 
Our solar system contains five dwarf planets.,(A) true (B) false,A,"The dwarf planets of our solar system are exciting proof of how much we are learning about our solar system. With the discovery of many new objects in our solar system, astronomers refined the definition of a dwarf planet in 2006. According to the IAU, a dwarf planet must: Orbit a star. Have enough mass to be nearly spherical. Not have cleared the area around its orbit of smaller objects. Not be a moon. "
The planet closest to the sun is Venus.,(A) true (B) false,B,"Venus thick clouds reflect sunlight well, so Venus is very bright. When it is visible, Venus is the brightest object in the sky besides the Sun and the Moon. Because the orbit of Venus is inside Earths orbit, Venus always appears close to the Sun. When Venus rises just before the Sun rises, the bright object is called the morning star. When it sets just after the Sun sets, it is the evening star. Of the planets, Venus is most similar to Earth in size and density. Venus is also our nearest neighbor. The planets interior structure is similar to Earths, with a large iron core and a silicate mantle (Figure 1.1). But the resemblance between the two inner planets ends there. "
The planet with the greatest mass and diameter is Saturn.,(A) true (B) false,B,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
Planets farther from the sun have orbits that are farther apart.,(A) true (B) false,A,"Figure 1.1 shows the relative sizes of the orbits of the planets, asteroid belt, and Kuiper belt. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. The orbits of the planets are not circular but slightly elliptical, with the Sun located at one of the foci (see opening image). While studying the solar system, Johannes Kepler discovered the relationship between the time it takes a planet to make one complete orbit around the Sun, its ""orbital period,"" and the distance from the Sun to the planet. If the orbital period of a planet is known, then it is possible to determine the planets distance from the Sun. This is how astronomers without modern telescopes could determine the distances to other planets within the solar system. How old are you on Earth? How old would you be if you lived on Jupiter? How many days is it until your birthday on Earth? How many days until your birthday if you lived on Saturn? Click image to the left or use the URL below. URL:  The relative sizes of the orbits of planets in the solar system. The inner solar sys- tem and asteroid belt is on the upper left. The upper right shows the outer planets and the Kuiper belt. "
The orbits of the planets are nearly circular.,(A) true (B) false,A,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
Our sun is the only star that has planets revolving around it.,(A) true (B) false,B,"Venus is the only planet that rotates clockwise as viewed from its North Pole. All of the other planets rotate counterclockwise. Venus turns slowly, making only one turn every 243 days. This is longer than a year on Venus! It takes Venus only 225 days to orbit the Sun. Because the orbit of Venus is inside Earths orbit, Venus always appears close to the Sun. You can see Venus rising early in the morning, just before the Sun rises. For this reason, Venus is sometimes called the morning star. When it sets in the evening, just after the Sun sets, it may be called the evening star. Since planets only reflect the Suns light, Venus should not be called a star at all! Venus is very bright because its clouds reflect sunlight very well. Venus is the brightest object in the sky besides the Sun and the Moon. "
Our solar system includes,(A) galaxies (B) asteroids (C) black holes (D) constellations,B,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
The early Earth-centered model of the universe was proposed by,(A) Galileo (B) Ptolemy (C) Copernicus (D) none of the above,B,"About 1,500 years after Ptolemy, Copernicus proposed a startling idea. He suggested that the Sun is at the center of the universe. Copernicus developed his model because it better explained the motions of the planets. Figure 25.2 shows both the Earth-centered and Sun-centered models. Copernicus did not publish his new model until his death. He knew that it was heresy to say that Earth was not the center of the universe. It wasnt until Galileo developed his telescope that people would take the Copernican "
The planet that is most similar to Earth in mass and diameter is,(A) Mars (B) Venus (C) Jupiter (D) Mercury,B,"Since the time of Copernicus, Kepler, and Galileo, we have learned a lot more about our solar system. Astronomers have discovered two more planets (Uranus and Neptune), five dwarf planets (Ceres, Pluto, Makemake, Haumea, and Eris), more than 150 moons, and many, many asteroids and other small objects. Although the Sun is just an average star compared to other stars, it is by far the largest object in the solar system. The Sun is more than 500 times the mass of everything else in the solar system combined! Table 1.1 gives data on the sizes of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter Object Mass (Relative to Earth) Mars Jupiter Saturn Uranus Neptune 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass 17.2 Earths mass Diameter of Planet (Relative to Earth) 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter 3.81 Earths diameter "
Which statement is true about the inner planets of our solar system?,(A) They formed before the sun formed (B) They formed from dense elements (C) They include Mars and Jupiter (D) They have very long years,B,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
All planets of our solar system orbit the sun,(A) in the same plane (B) at the same speed (C) in the same direction (D) two of the above,D,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
How long the day lasts on a planet depends on its,(A) distance from the sun (B) speed of revolution (C) speed of rotation (D) length of orbit,C,"Figure 25.4 shows the Sun and planets with the correct sizes. The distances between them are way too small. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. In Figure 25.5, you can see that the orbits of the planets are nearly circular. Plutos orbit is a much longer ellipse. Some astronomers think Pluto was dragged into its orbit by Neptune. Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km (93 million miles). Table 25.2 shows the distance from the Sun to each planet in AU. The table shows how long it takes each planet to spin on its axis. It also shows how long it takes each planet to complete an orbit. Notice how slowly Venus rotates! A day on Venus is actually longer than a year on Venus! Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 (In "
"To be a planet, an object must",(A) be big enough that its own gravity makes it round (B) have cleared its path of smaller objects (C) orbit a star (D) all of the above,D,"In 2006, the International Astronomical Union decided that there were too many questions surrounding what could be called a planet, and so refined the definition of a planet. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be shaped as a sphere. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. "
hottest of all the planets in the solar system,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,G,"Jupiter, shown in Figure 25.19, is the largest planet in our solar system. Jupiter is named for the king of the gods in Roman mythology. Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earths volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from the Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
What explains the number of impact craters on Mercury?,(A) It is very close to the Sun (B) The craters have been overrun by lava flows (C) It is not geologically active (D) It is subject to constant storms,C,"The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. "
rover that explored Mars surface,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,B,"We continue to explore the solar system. A rover is like a spacecraft on wheels (Figure 23.29). It can wheel around on the surface. Scientists on Earth tell it where to go. The craft then collects and sends back data from that locations. The Mars Pathfinder studied the red planet for nearly three months in 1997. Two more rovers, Spirit and Opportunity, landed on Mars in 2004. Both were only designed to last 90 days, but have lasted many times longer. Spirit sent back data until it became stuck in January 2010. Opportunity continues to explore Mars. Several spacecraft are currently in orbit, studying the Martian surface and thin atmosphere. "
The largest volcano in the solar system is a __________ volcano a on the planet ___________.,(A) composite; Mars (B) shield; Mars (C) composite; Venus (D) shield; Venus,B,"Mars is home to the largest volcano in the solar system. Olympus Mons is shown in Figure 25.16. Olympus Mons is a shield volcano. The volcano is similar to the volcanoes of the Hawaiian Islands. But Olympus Mons is a giant, about 27 km (16.7 miles/88,580 ft) tall. Thats three times taller than Mount Everest! At its base, Olympus Mons is about the size of the entire state of Arizona. Mars also has the largest canyon in the solar system, Valles Marineris (Figure 25.17). This canyon is 4,000 km (2,500 miles) long. Thats as long as Europe is wide! One-fifth of the circumference of Mars is covered by the canyon. Valles Marineris is 7 km (4.3 miles) deep. How about Earths Grand Canyon? Earths most famous canyon is only 446 km (277 miles) long and about 2 km (1.2 miles) deep. Mars has mountains, canyons, and other features similar to Earth. But it doesnt have as much geological activity as Earth. There is no evidence of plate tectonics on Mars. There are also more craters on Mars than on Earth. Buy there are fewer craters than on the Moon. What does this suggest to you regarding Mars plate tectonic history? "
only planet in the solar system known to have plate tectonics,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,E,"For decades Pluto was a planet. But even then, scientists knew it was an unusual planet. The other outer planets are all gas giants. Pluto is small, icy and rocky. With a diameter of about 2400 kilometers, it has only about 1/5 the mass of Earths Moon. The other planets orbit in a plane. Plutos orbit is tilted. The shape of the orbit is like a long, narrow ellipse. Plutos orbit is so elliptical that sometimes it is inside the orbit of Neptune. Plutos orbit is in the Kuiper belt. We have discovered more than 200 million Kuiper belt objects. Pluto has 3 moons of its own. The largest, Charon, is big. Some scientists think that Pluto-Charon system is a double dwarf planet (Figure 25.37). Two smaller moons, Nix and Hydra, were discovered in 2005. "
What is true of life on the inner planets?,(A) Earths Moon had life in ancient oceans (B) Venus has microbes beneath its thick atmosphere (C) Mars has ancient fossil microbes (D) There is only life on Earth,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
Why is Venus the hottest planet?,(A) It is closest to the Sun (B) It has a powerful greenhouse effect (C) It has the most internal heat (D) It spins the fastest,B,"Viewed through a telescope, Venus looks smooth and featureless. The planet is covered by a thick layer of clouds. You can see the clouds in pictures of Venus, such as Figure 25.11. We make maps of the surface using radar, because the thick clouds wont allow us to take photographs of the surface of Venus. Figure 25.12 shows the topographical features of Venus. The image was produced by the Magellan probe on a flyby. Radar waves sent by the spacecraft reveal mountains, valleys, vast lava plains, and canyons. Like Mercury, Venus does not have a moon. Clouds on Earth are made of water vapor. Venuss clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earths surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465C (860F). Thats hot enough to melt lead! "
any of the four planets closest to the sun,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
smallest of all the planets in the solar system,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,A,"The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. "
Evidence for liquid water in the Martian past includes,(A) water-eroded canyons (B) fossil fish (C) the presence of polar ice currently (D) all of these,A,"Water on Mars cant be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when volcanoes erupt. At this times liquid water flows across the surface. Scientists think that there was once liquid water on the planet. There are many surface features that look like water- eroded canyons. The Mars rover collected round clumps of crystals that, on Earth, usually form in water. If there was liquid water on Mars, life might have existed there in the past. "
spacecraft that is orbiting and studying Mercury,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,F,"The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. "
planet with the largest volcano in the solar system,(A) Mercury (B) Opportunity (C) Mars (D) inner planet (E) Earth (F) Messenger (G) Venus,C,"Mars is home to the largest volcano in the solar system. Olympus Mons is shown in Figure 25.16. Olympus Mons is a shield volcano. The volcano is similar to the volcanoes of the Hawaiian Islands. But Olympus Mons is a giant, about 27 km (16.7 miles/88,580 ft) tall. Thats three times taller than Mount Everest! At its base, Olympus Mons is about the size of the entire state of Arizona. Mars also has the largest canyon in the solar system, Valles Marineris (Figure 25.17). This canyon is 4,000 km (2,500 miles) long. Thats as long as Europe is wide! One-fifth of the circumference of Mars is covered by the canyon. Valles Marineris is 7 km (4.3 miles) deep. How about Earths Grand Canyon? Earths most famous canyon is only 446 km (277 miles) long and about 2 km (1.2 miles) deep. Mars has mountains, canyons, and other features similar to Earth. But it doesnt have as much geological activity as Earth. There is no evidence of plate tectonics on Mars. There are also more craters on Mars than on Earth. Buy there are fewer craters than on the Moon. What does this suggest to you regarding Mars plate tectonic history? "
All of the inner planets were once geologically active.,(A) true (B) false,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
Venus has the largest greenhouse effect of the inner planets.,(A) true (B) false,A,"Venus thick clouds reflect sunlight well, so Venus is very bright. When it is visible, Venus is the brightest object in the sky besides the Sun and the Moon. Because the orbit of Venus is inside Earths orbit, Venus always appears close to the Sun. When Venus rises just before the Sun rises, the bright object is called the morning star. When it sets just after the Sun sets, it is the evening star. Of the planets, Venus is most similar to Earth in size and density. Venus is also our nearest neighbor. The planets interior structure is similar to Earths, with a large iron core and a silicate mantle (Figure 1.1). But the resemblance between the two inner planets ends there. "
Venus is the only inner planet with a large moon besides Earth.,(A) true (B) false,B,"Named after the Roman goddess of love, Venus is the only planet named after a female. Venus is sometimes called Earths sister planet. But just how similar is Venus to Earth? Venus is our nearest neighbor. Venus is most like Earth in size. "
"Besides Earth, the inner planets are all solid.",(A) true (B) false,B,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
The inner planets spin faster than the outer planets.,(A) true (B) false,B,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
All of the inner planets,(A) have very rapid rotation (B) have a thick atmosphere (C) have one or more moons (D) are solid (E) dense (F) and rocky,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
Which statement about Mercurys core is false?,(A) It is very small (B) It contains mostly iron (C) It exists in a molten state (D) It makes up 42% of Mercurys volume,A,Figure 25.10 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Scientists think that the interior contains a large core made mostly of melted iron. Mercurys core takes up about 42% of the planets volume. Mercurys highly cratered surface is evidence that Mercury is not geologically active. 
Venus has all of the following except,(A) moons (B) valleys (C) mountains (D) lava plains,A,"Viewed through a telescope, Venus looks smooth and featureless. The planet is covered by a thick layer of clouds. You can see the clouds in pictures of Venus, such as Figure 25.11. We make maps of the surface using radar, because the thick clouds wont allow us to take photographs of the surface of Venus. Figure 25.12 shows the topographical features of Venus. The image was produced by the Magellan probe on a flyby. Radar waves sent by the spacecraft reveal mountains, valleys, vast lava plains, and canyons. Like Mercury, Venus does not have a moon. Clouds on Earth are made of water vapor. Venuss clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earths surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465C (860F). Thats hot enough to melt lead! "
Which process explains why Venus is very hot?,(A) greenhouse effect (B) volcanic activity (C) plate tectonics (D) none of the above,A,"Viewed through a telescope, Venus looks smooth and featureless. The planet is covered by a thick layer of clouds. You can see the clouds in pictures of Venus, such as Figure 25.11. We make maps of the surface using radar, because the thick clouds wont allow us to take photographs of the surface of Venus. Figure 25.12 shows the topographical features of Venus. The image was produced by the Magellan probe on a flyby. Radar waves sent by the spacecraft reveal mountains, valleys, vast lava plains, and canyons. Like Mercury, Venus does not have a moon. Clouds on Earth are made of water vapor. Venuss clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earths surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465C (860F). Thats hot enough to melt lead! "
The inner planet with an average surface temperature of 14 C is,(A) Mercury (B) Venus (C) Earth (D) Mars,C,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
Mars does not usually have liquid water on its surface because the,(A) air of the planets atmosphere is too dense (B) pressure of the planets atmosphere is too low (C) temperature of the planets surface is too high (D) two of the above,A,"Water on Mars cant be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when volcanoes erupt. At this times liquid water flows across the surface. Scientists think that there was once liquid water on the planet. There are many surface features that look like water- eroded canyons. The Mars rover collected round clumps of crystals that, on Earth, usually form in water. If there was liquid water on Mars, life might have existed there in the past. "
The largest canyon in the solar system is found on,(A) Mars (B) Earth (C) Venus (D) Mercury,A,"Mars has mountains, canyons, and other features similar to Earth. Some of these surface features are amazing for their size! Olympus Mons is a shield volcano, similar to the volcanoes that make up the Hawaiian Islands. But Olympus Mons is also the largest mountain in the solar system (Figure 1.2). Mars also has the largest canyon in the solar system, Valles Marineris (Figure 1.3). "
None of the inner planets of the solar system has rings.,(A) true (B) false,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
"Compared with the outer planets, the inner planets spin more quickly.",(A) true (B) false,B,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
All of the inner planets are made of cooled igneous rock.,(A) true (B) false,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
Each year on Mercury lasts just 58 Earth days.,(A) true (B) false,B,"Mercury is named for the Roman messenger god, who could run extremely quickly, just as the planet moves very quickly in its orbit around the Sun. A year on Mercury  the length of time it takes to orbit the Sun  is just 88 Earth days. Despite its very short years, Mercury has very long days. A day is defined as the time it takes a planet to turn on its axis. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 57 Earth days long. In other words, on Mercury, a year is only a Mercury day and a half long! "
Most of Mercury is extremely wet.,(A) true (B) false,B,"Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. "
Clouds on Venus contain sulfur.,(A) true (B) false,A,"Venus is covered by a thick layer of clouds, as shown in pictures of Venus taken at ultraviolet wavelengths (Figure This ultraviolet image from the Pioneer Venus Orbiter shows thick layers of clouds in the atmosphere of Venus. Venus clouds are not made of water vapor like Earths clouds. Clouds on Venus are made mostly of carbon dioxide Click image to the left or use the URL below. URL:  The atmosphere of Venus is so thick that the atmospheric pressure on the planets surface is 90 times greater than the atmospheric pressure on Earths surface. The dense atmosphere totally obscures the surface of Venus, even from spacecraft orbiting the planet. "
A day on Venus is longer than a year on Venus.,(A) true (B) false,A,"Venus rotates in a direction opposite the other planets and opposite to the direction it orbits the Sun. This rotation is extremely slow, only one turn every 243 Earth days. This is longer than a year on Venus  it takes Venus only 224 days to orbit the Sun. Diagram of Venuss interior, which is simi- lar to Earths. "
Life could evolve on Earth because its atmosphere contained oxygen.,(A) true (B) false,B,"When photosynthesis evolved and spread around the planet, oxygen was released in abundance. The addition of oxygen is what created Earths third atmosphere. This event, which occurred about 2.5 billion years ago, is sometimes called the oxygen catastrophe because so many organisms died. Although entire species died out and went extinct, this event is also called the Great Oxygenation Event because it was a great opportunity. The organisms that survived developed a use for oxygen through cellular respiration, the process by which cells can obtain energy from organic molecules. This opened up many opportunities for organisms to evolve to fill different niches and many new types of organisms first appeared on Earth. "
Some features on Mars surface look as though they were eroded by water.,(A) true (B) false,A,"Water on Mars cant be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when volcanoes erupt. At this times liquid water flows across the surface. Scientists think that there was once liquid water on the planet. There are many surface features that look like water- eroded canyons. The Mars rover collected round clumps of crystals that, on Earth, usually form in water. If there was liquid water on Mars, life might have existed there in the past. "
Mars moons were meteorites that were captured by Martian gravity.,(A) true (B) false,B,"Mars has two very small, irregular moons, Phobos (seen in Figure 25.18) and Deimos. These moons were discovered in 1877. They are named after the two sons of Ares, who followed their father into war. The moons were probably asteroids that were captured by Martian gravity. "
The heat to create liquid water on Europa is from,(A) radioactive decay (B) its molten core (C) the Sun (D) the gravitational pull of Jupiter,D,"Over time, Earth cooled. The surface hardened to become solid rock. Volcanic eruptions, like the one in Figure 14.1, brought lava and gases to the surface. One of the gases was water vapor. More water vapor came from asteroids and comets that crashed into Earth. As Earth cooled still more, the water vapor condensed to make Earths first liquid water. At last, the oceans could start to form. "
Saturn is the only planet with rings.,(A) true (B) false,B,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
Jupiter may have a small rocky core.,(A) true (B) false,A,"Since Jupiter is a gas giant, could a spacecraft land on its surface? The answer is no. There is no solid surface at all! Jupiter is made mostly of hydrogen, with some helium, and small amounts of other elements. The outer layers of the planet are gas. Deeper within the planet, the intense pressure condenses the gases into a liquid. Jupiter may have a small rocky core at its center. "
What are Saturns rings?,(A) ice and dust (B) a broken up moon (C) a magnetic field (D) captured asteroids,A,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
Jupiter has fewer than 30 moons.,(A) true (B) false,B,"Jupiter has lots of moons. As of 2011, we have discovered over 60 natural satellites of Jupiter. Four are big enough and bright enough to be seen from Earth using a pair of binoculars. These four moons were first discovered by Galileo in 1610. They are called the Galilean moons. Figure 25.21 shows the four Galilean moons and their sizes relative to Jupiters Great Red Spot. These moons are named Io, Europa, Ganymede, and Callisto. The Galilean moons are larger than even the biggest dwarf planets, Pluto and Eris. Ganymede is the biggest moon in the solar system. It is even larger than the planet Mercury! Scientists think that Europa is a good place to look for extraterrestrial life. Europa is the smallest of the Galilean moons. The moons surface is a smooth layer of ice. Scientists think that the ice may sit on top of an ocean of liquid water. How could Europa have liquid water when it is so far from the Sun? Europa is heated by Jupiter. Jupiters tidal forces are so great that they stretch and squash its moon. This could produce enough heat for there to be liquid water. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecrafts, Voyager 1 and Voyager 2, visited Jupiter and its moons. Photos from the Voyager missions "
What is the Great Red Spot?,(A) Iron oxide in the asteroid belt (B) A giant storm on Jupiter (C) The planet Mars (D) An enormous volcano on Neptune,B,"The upper layer of Jupiters atmosphere contains clouds of ammonia (NH3 ) in bands of different colors. These bands rotate around the planet, but also swirl around in turbulent storms. The Great Red Spot (Figure 1.3) is an enormous, oval-shaped storm found south of Jupiters equator. This storm is more than three times as wide as the entire Earth. Clouds in the storm rotate in a counterclockwise direction, making one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years, since astronomers could first see the storm through telescopes. Do you think the Great Red Spot is a permanent feature on Jupiter? How could you know? This image of Jupiters Great Red Spot (upper right of image) was taken by the Voyager 1 spacecraft. The white storm just below the Great Red Spot is about the same diameter as Earth. "
How was Neptune discovered?,(A) through a radio telescope (B) by the Hubble Space telescope (C) Uranus orbit was unexpected (D) because it wanders across the sky like the other planets,C,"Neptune, shown in Figure 1.1, is the only major planet that cant be seen from Earth without a telescope. Scientists predicted the existence of Neptune before it was discovered because Uranus did not always appear exactly where it should appear. They knew that the gravitational pull of another planet beyond Uranus must be affecting Uranus orbit. Neptune was discovered in 1846, in the position that had been predicted, and it was named Neptune for the Roman god of the sea because of its bluish color. This image of Neptune was taken by Voy- ager 2 in 1989. The Great Dark Spot seen on the left center in the picture has since disappeared, but a similar dark spot has appeared on another part of the planet. In many respects, Neptune is similar to Uranus (Figure 1.2). Neptune has slightly more mass than Uranus, but it is slightly smaller in size. Neptune is much farther from the Sun, at nearly 4.5 billion km (2.8 billion mi). The planets slow orbit means that it takes 165 Earth years to go once around the Sun. "
Jupiters moon Europa has some conditions suitable for life.,(A) true (B) false,A,"Jupiter has lots of moons. As of 2011, we have discovered over 60 natural satellites of Jupiter. Four are big enough and bright enough to be seen from Earth using a pair of binoculars. These four moons were first discovered by Galileo in 1610. They are called the Galilean moons. Figure 25.21 shows the four Galilean moons and their sizes relative to Jupiters Great Red Spot. These moons are named Io, Europa, Ganymede, and Callisto. The Galilean moons are larger than even the biggest dwarf planets, Pluto and Eris. Ganymede is the biggest moon in the solar system. It is even larger than the planet Mercury! Scientists think that Europa is a good place to look for extraterrestrial life. Europa is the smallest of the Galilean moons. The moons surface is a smooth layer of ice. Scientists think that the ice may sit on top of an ocean of liquid water. How could Europa have liquid water when it is so far from the Sun? Europa is heated by Jupiter. Jupiters tidal forces are so great that they stretch and squash its moon. This could produce enough heat for there to be liquid water. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecrafts, Voyager 1 and Voyager 2, visited Jupiter and its moons. Photos from the Voyager missions "
Thunderstorms have been observed on Uranus.,(A) true (B) false,B,"Like Jupiter and Saturn, Uranus is composed mainly of hydrogen and helium, with an outer gas layer that gives way to liquid on the inside. Uranus has a higher percentage of icy materials, such as water, ammonia (NH3 ), and methane (CH4 ), than Jupiter and Saturn. When sunlight reflects off Uranus, clouds of methane filter out red light, giving the planet a blue-green color. There are bands of clouds in the atmosphere of Uranus, but they are hard to see in normal light, so the planet looks like a plain blue ball. "
Why are Uranus and Neptune blue?,(A) They are composed of solid water ice (B) Methane in their atmosphere filters out red light (C) They are covered by blue oceans (D) They are covered by blue algae,B,"Like Uranus, Neptune is blue. The blue color is caused by gases in its atmosphere, including methane. Neptune is not a smooth looking ball like Uranus. The planet has a few darker and lighter spots. When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot south of the equator. This spot was called the Great Dark Spot. When the Hubble Space Telescope photographed Neptune in 1994, the Great Dark Spot had disappeared. Another dark spot had appeared north of the equator. Astronomers believe that both of these spots represent gaps in the methane clouds on Neptune. Neptunes appearance changes due to its turbulent atmosphere. Winds are stronger than on any other planet in the solar system. Wind speeds can reach 1,100 km/h (700 mph). This is close to the speed of sound! The rapid winds surprised astronomers. This is because Neptune receives little energy from the Sun to power weather systems. It is not surprising that Neptune is one of the coldest places in the solar system. Temperatures at the top of the clouds are about 218C (360F). "
Saturns rings were first observed by the Hubble space telescope.,(A) true (B) false,B,"Saturns rings were first observed by Galileo in 1610. He didnt know they were rings and thought that they were two large moons. One moon was on either side of the planet. In 1659, the Dutch astronomer Christiaan Huygens realized that they were rings circling Saturns equator. The rings appear tilted. This is because Saturn is tilted about 27 degrees to its side. The Voyager 1 spacecraft visited Saturn in 1980. Voyager 2 followed in 1981. These probes sent back detailed pictures of Saturn, its rings, and some of its moons. From the Voyager data, we learned that Saturns rings are made of particles of water and ice with a little bit of dust. There are several gaps in the rings. These gaps were cleared out by moons within the rings. Ring dust and gas are attracted to the moon by its gravity. This leaves a gap in the rings. Other gaps in the rings are caused by the competing forces of Saturn and its moons outside the rings. "
Uranus is tilted sideways because of the pull of Neptunes gravity.,(A) true (B) false,B,"Most of the planets in the solar system rotate on their axes in the same direction that they move around the Sun. Uranus, though, is tilted on its side, so its axis is almost parallel to its orbit. In other words, it rotates like a top that was turned so that it was spinning parallel to the floor. Scientists think that Uranus was probably knocked over by a collision with another planet-sized object billions of years ago. "
Neptune is so far from Earth that it can be seen only with a telescope.,(A) true (B) false,A,"Neptune, shown in Figure 1.1, is the only major planet that cant be seen from Earth without a telescope. Scientists predicted the existence of Neptune before it was discovered because Uranus did not always appear exactly where it should appear. They knew that the gravitational pull of another planet beyond Uranus must be affecting Uranus orbit. Neptune was discovered in 1846, in the position that had been predicted, and it was named Neptune for the Roman god of the sea because of its bluish color. This image of Neptune was taken by Voy- ager 2 in 1989. The Great Dark Spot seen on the left center in the picture has since disappeared, but a similar dark spot has appeared on another part of the planet. In many respects, Neptune is similar to Uranus (Figure 1.2). Neptune has slightly more mass than Uranus, but it is slightly smaller in size. Neptune is much farther from the Sun, at nearly 4.5 billion km (2.8 billion mi). The planets slow orbit means that it takes 165 Earth years to go once around the Sun. "
Scientists think that Neptunes moon Triton was once part of Neptune.,(A) true (B) false,B,"Neptune has faint rings of ice and dust that may change or disappear in fairly short time frames. Neptune has 13 known moons. Triton, shown in Figure 1.3, is the only one of them that has enough mass to be spherical in shape. Triton orbits in the direction opposite to the orbit of Neptune. Scientists think Triton did not form around Neptune, but instead was captured by Neptunes gravity as it passed by. This image of Triton, Neptunes largest moon, was taken by Voyager 2 in 1989. "
largest planet in the solar system,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,E,"Jupiter, shown in Figure 25.19, is the largest planet in our solar system. Jupiter is named for the king of the gods in Roman mythology. Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earths volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from the Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
It takes Jupiter 5 Earth years to make one orbit around the Sun.,(A) true (B) false,B,"Jupiter, shown in Figure 25.19, is the largest planet in our solar system. Jupiter is named for the king of the gods in Roman mythology. Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earths volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from the Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
only planet that is tilted on its side,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,G,"Most of the planets in the solar system rotate on their axes in the same direction that they move around the Sun. Uranus, though, is tilted on its side, so its axis is almost parallel to its orbit. In other words, it rotates like a top that was turned so that it was spinning parallel to the floor. Scientists think that Uranus was probably knocked over by a collision with another planet-sized object billions of years ago. "
Most moons in the solar system are captured asteroids.,(A) true (B) false,A,"Hundreds of thousands of asteroids have been discovered in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month. The majority of the asteroids are found in between the orbits of Mars In 1991, Asteroid 951 Gaspra was the first asteroid photographed at close range. Gaspra is a medium-sized asteroid, mea- suring about 19 by 12 by 11 km (12 by 7.5 by 7 mi). and Jupiter, in a region called the asteroid belt, as shown in Figure 1.2. Although there are many thousands of asteroids in the asteroid belt, their total mass adds up to only about 4% of Earths Moon. The white dots in the figure are asteroids in the main asteroid belt. Other groups of asteroids closer to Jupiter are called the Hildas (orange), the Trojans (green), and the Greeks (also green). Scientists think that the bodies in the asteroid belt formed during the formation of the solar system. The asteroids might have come together to make a single planet, but they were pulled apart by the intense gravity of Jupiter. "
planet with stronger winds than any other planet in the solar system,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,C,"Jupiters atmosphere is unlike any other in the solar system! The upper layer contains clouds of ammonia. The ammonia is different colored bands. These bands rotate around the planet. The ammonia also swirls around in tremendous storms. The Great Red Spot, shown in Figure 25.20, is Jupiters most noticeable feature. The spot is an enormous, oval-shaped storm. It is more than three times as wide as the entire Earth! Clouds in the storm rotate counterclockwise. They make one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years. It may have been observed as early as 1664. It is possible that this storm is a permanent feature on Jupiter. No one knows for sure. "
Jupiters four largest moons are larger than the dwarf planet Pluto.,(A) true (B) false,A,"Jupiter has lots of moons. As of 2011, we have discovered over 60 natural satellites of Jupiter. Four are big enough and bright enough to be seen from Earth using a pair of binoculars. These four moons were first discovered by Galileo in 1610. They are called the Galilean moons. Figure 25.21 shows the four Galilean moons and their sizes relative to Jupiters Great Red Spot. These moons are named Io, Europa, Ganymede, and Callisto. The Galilean moons are larger than even the biggest dwarf planets, Pluto and Eris. Ganymede is the biggest moon in the solar system. It is even larger than the planet Mercury! Scientists think that Europa is a good place to look for extraterrestrial life. Europa is the smallest of the Galilean moons. The moons surface is a smooth layer of ice. Scientists think that the ice may sit on top of an ocean of liquid water. How could Europa have liquid water when it is so far from the Sun? Europa is heated by Jupiter. Jupiters tidal forces are so great that they stretch and squash its moon. This could produce enough heat for there to be liquid water. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecrafts, Voyager 1 and Voyager 2, visited Jupiter and its moons. Photos from the Voyager missions "
gap in the clouds on Neptune,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,A,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
circular cloud of dust and other small particles that orbit an outer planet,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,D,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
Astronauts have tested samples from Europa for signs extraterrestrial life.,(A) true (B) false,B,"Scientists are very interested in asteroids. Most are composed of material that has not changed since early in the solar system. Scientists can learn a lot from them about how the solar system formed. Asteroids may be important for space travel. They could be mined for rare minerals or for construction projects in space. Scientists have sent spacecraft to study asteroids. In 1997, the NEAR Shoemaker probe orbited the asteroid 433 Eros. The craft finally landed on its surface in 2001. The Japanese Hayabusa probe returned to Earth with samples of a small near-earth asteroid in 2010. The U.S. Dawn mission will visit Vesta in 2011 and Ceres in 2015. "
Saturn is unique because it is the only planet with rings.,(A) true (B) false,B,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
least dense planet in the solar system,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,B,"Figure 1.3 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Its relatively large, liquid core, made mostly of melted iron, takes up about 42% of the planets volume. "
enormous storm on Jupiter,(A) Great Dark Spot (B) Saturn (C) Neptune (D) planetary ring (E) Jupiter (F) Great Red Spot (G) Uranus,F,"Jupiters atmosphere is unlike any other in the solar system! The upper layer contains clouds of ammonia. The ammonia is different colored bands. These bands rotate around the planet. The ammonia also swirls around in tremendous storms. The Great Red Spot, shown in Figure 25.20, is Jupiters most noticeable feature. The spot is an enormous, oval-shaped storm. It is more than three times as wide as the entire Earth! Clouds in the storm rotate counterclockwise. They make one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years. It may have been observed as early as 1664. It is possible that this storm is a permanent feature on Jupiter. No one knows for sure. "
The outer planets of the eight planets in our solar system include,(A) Mars (B) Jupiter (C) Pluto (D) two of the above,B,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
"Compared with the inner planets, the outer planets",(A) are much larger (B) are much denser (C) have more moons (D) two of the above,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
The planet that has clouds of ammonia is,(A) Uranus (B) Neptune (C) Jupiter (D) Saturn,C,"Jupiters atmosphere is unlike any other in the solar system! The upper layer contains clouds of ammonia. The ammonia is different colored bands. These bands rotate around the planet. The ammonia also swirls around in tremendous storms. The Great Red Spot, shown in Figure 25.20, is Jupiters most noticeable feature. The spot is an enormous, oval-shaped storm. It is more than three times as wide as the entire Earth! Clouds in the storm rotate counterclockwise. They make one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years. It may have been observed as early as 1664. It is possible that this storm is a permanent feature on Jupiter. No one knows for sure. "
The biggest moon in the solar system orbits,(A) Neptune (B) Uranus (C) Saturn (D) Jupiter,D,"Jupiter has lots of moons. As of 2011, we have discovered over 60 natural satellites of Jupiter. Four are big enough and bright enough to be seen from Earth using a pair of binoculars. These four moons were first discovered by Galileo in 1610. They are called the Galilean moons. Figure 25.21 shows the four Galilean moons and their sizes relative to Jupiters Great Red Spot. These moons are named Io, Europa, Ganymede, and Callisto. The Galilean moons are larger than even the biggest dwarf planets, Pluto and Eris. Ganymede is the biggest moon in the solar system. It is even larger than the planet Mercury! Scientists think that Europa is a good place to look for extraterrestrial life. Europa is the smallest of the Galilean moons. The moons surface is a smooth layer of ice. Scientists think that the ice may sit on top of an ocean of liquid water. How could Europa have liquid water when it is so far from the Sun? Europa is heated by Jupiter. Jupiters tidal forces are so great that they stretch and squash its moon. This could produce enough heat for there to be liquid water. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecrafts, Voyager 1 and Voyager 2, visited Jupiter and its moons. Photos from the Voyager missions "
Scientists think that Saturns moon Titan may,(A) have an atmosphere like early Earths (B) be larger than Earths moon (C) have lakes of liquid water (D) all of the above,A,"Most of Saturns moons are very small, and only seven are large enough for gravity to have made them spherical. Only Titan is larger than Earths Moon at about 1.5 times its size. Titan is even larger than the planet Mercury. Scientists are interested in Titan because its atmosphere is similar to what Earths was like before life developed. Nitrogen is dominant and methane is the second most abundant gas. Titan may have a layer of liquid water and ammonia under a layer of surface ice. Lakes of liquid methane (CH4 ) and ethane (C2 H6 ) are found on Titans surface. Although conditions are similar enough to those of early Earth for scientists to speculate that extremely A color-exaggerated mosaic of Saturn and its rings taken by Cassini as Saturn eclipses the Sun. A close-up of Saturns outer C ring show- ing areas with higher particle concentra- tion and gaps. This composite image compares Saturns largest moon, Titan (right) to Earth (left). Click image to the left or use the URL below. URL: "
Which two outer planets are called sister planets because they are very similar?,(A) Jupiter and Saturn (B) Saturn and Uranus (C) Uranus and Neptune (D) Jupiter and Uranus,C,"Named after the Roman goddess of love, Venus is the only planet named after a female. Venus is sometimes called Earths sister planet. But just how similar is Venus to Earth? Venus is our nearest neighbor. Venus is most like Earth in size. "
Neptune and Uranus appear to be blue due to the,(A) oceans of water on their surface (B) methane gas in their atmosphere (C) minerals in their rocky crust (D) frigid cold of their surface,B,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
Near-Earth asteroids,(A) have orbits that cross Earths (B) number more than 4 (C) 500 (D) c could strike Earth (E) d all of these,D,"Near-Earth asteroids have orbits that cross Earths orbit. This means that they can collide with Earth. There are over 4,500 known near-Earth asteroids. Small asteroids do sometimes collide with Earth. An asteroid about 510 m in diameter hits about once per year. Five hundred to a thousand of the known near-Earth asteroids are much bigger. They are over 1 kilometer in diameter. When large asteroids hit Earth in the past, many organisms died. At times, many species became extinct. Astronomers keep looking for near-Earth asteroids. They hope to predict a possible collision early so they can to try to stop it. "
Which two planets does the asteroid belt fall between?,(A) Earth Mars (B) Mars Jupiter (C) Jupiter Neptune (D) Mercury Venus,B,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
Why do scientists value meteorites?,(A) They are material from the earliest solar system (B) They are an important source of valuable metals (C) They contain metals not otherwise found on Earth (D) none of these,A,"Although most meteors burn up in the atmosphere, larger meteoroids may strike the Earths surface to create a meteorite. Meteorites are valuable to scientists because they provide clues about our solar system. Many meteorites are from asteroids that formed when the solar system formed (Figure 1.2). A few meteorites are made of rocky material that is thought to have come from Mars when an asteroid impact shot material off the Martian surface and into space. Click image to the left or use the URL below. URL: "
What is the asteroid belt?,(A) It is a large planet that was broken apart by an asteroid impact (B) It is where the Suns gravity is perfect for asteroids (C) It is debris that couldnt form a planet due to Jupiters gravity (D) none of these,C,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
Why is the dwarf planet Ceres not classified as a large asteroid?,(A) it is rounded (B) it is too large (C) it does not have craters (D) it is a moon of Pluto,A,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
Most asteroids in the solar system are located between Mars and Earth.,(A) true (B) false,B,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
Asteroids formed after the rest of the solar system formed.,(A) true (B) false,B,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
Small asteroids sometimes collide with Earth.,(A) true (B) false,A,"Near-Earth asteroids have orbits that cross Earths orbit. This means that they can collide with Earth. There are over 4,500 known near-Earth asteroids. Small asteroids do sometimes collide with Earth. An asteroid about 510 m in diameter hits about once per year. Five hundred to a thousand of the known near-Earth asteroids are much bigger. They are over 1 kilometer in diameter. When large asteroids hit Earth in the past, many organisms died. At times, many species became extinct. Astronomers keep looking for near-Earth asteroids. They hope to predict a possible collision early so they can to try to stop it. "
All shooting stars become meteorites.,(A) true (B) false,B,"If you look at the sky on a dark night, you may see a meteor, like in Figure 25.33. A meteor forms a streak of light across the sky. People call them shooting stars because thats what they look like. But meteors are not stars at all. The light you see comes from a small piece of matter burning up as it flies through Earths atmosphere. "
"After a meteor hits Earths surface, it is called a meteorite.",(A) true (B) false,A,"A meteor, such as in Figure 1.1, is a streak of light across the sky. People call them shooting stars but they are actually small pieces of matter burning up as they enter Earths atmosphere from space. Meteors are called meteoroids before they reach Earths atmosphere. Meteoroids are smaller than asteroids and range from the size of boulders down to the size of tiny sand grains. Still smaller objects are called interplanetary dust. When Earth passes through a cluster of meteoroids, there is a meteor shower. These clusters are often remnants left behind by comet tails. "
Comet orbits are similar in shape to planet orbits.,(A) true (B) false,B,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
Meteoroids are usually larger than asteroids.,(A) true (B) false,B,"Before these small pieces of matter enter Earths atmosphere, they are called meteoroids. Meteoroids are as large as boulders or as small as tiny sand grains. Larger objects are called asteroids; smaller objects are interplanetary dust. Meteoroids sometimes cluster together in long trails. They are the debris left behind by comets. When Earth passes through a comet trail, there is a meteor shower. During a meteor shower, there are many more meteors than normal for a night or two. "
Comets are commonly called shooting stars.,(A) true (B) false,B,"If you look at the sky on a dark night, you may see a meteor, like in Figure 25.33. A meteor forms a streak of light across the sky. People call them shooting stars because thats what they look like. But meteors are not stars at all. The light you see comes from a small piece of matter burning up as it flies through Earths atmosphere. "
The longest period comets come from the Kuiper belt.,(A) true (B) false,B,"Some comets have periods of 200 years or less. They are called short-period comets. Short-period comets are from a region beyond the orbit of Neptune called the Kuiper Belt. Kuiper is pronounced KI-per, rhyming with viper. The Kuiper Belt is home to comets, asteroids, and at least two dwarf planets. Some comets have periods of thousands or even millions of years. Most long-period comets come from a very distant region of the solar system. This region is called the Oort cloud. The Oort cloud is about 50,000100,000 times the distance from the Sun to Earth. Comets carry materials in from the outer solar system. Comets may have brought water into the early Earth. Other substances could also have come from comets. "
A comet has an atmosphere only when it gets close to the sun.,(A) true (B) false,A,"Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This atmosphere is called a coma. Radiation and particles streaming from the Sun push some of this gas and dust into a long tail. A comets tail always points away from the Sun, no matter which way the comet is moving. Why do you think that is? Figure Gases in the coma and tail of a comet reflect light from the Sun. Comets are very hard to see except when they have comas and tails. That is why they appear only when they are near the Sun. They disappear again as they move back to the outer solar system. The time between one visit from a comet and the next is called the comets period. The first comet whose period was known was Halleys Comet. Its period is 75 years. Halleys Comet last traveled through the inner solar system in 1986. The comet will appear again in 2061. Who will look up at it? "
Any object whose orbit crosses Earths can collide with Earth.,(A) true (B) false,A,"More than 4,500 asteroids cross Earths orbit; they are near-Earth asteroids. Between 500 and 1,000 of these are over 1 km in diameter. Any object whose orbit crosses Earths can collide with Earth, and many asteroids do. On average, each year a rock about 5-10 m in diameter hits Earth (Figure 1.3). Since past asteroid impacts have been implicated in mass extinctions, astronomers are always on the lookout for new asteroids, and follow the known near-Earth asteroids closely, so they can predict a possible collision as early as possible. A painting of what an asteroid a few kilometers across might look like as it strikes Earth. "
Halleys Comet is it expected to return in 2061.,(A) true (B) false,A,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
Scientists think that comets may have brought water to early Earth.,(A) true (B) false,A,"The early atmosphere was rich in water vapor from volcanic eruptions and comets. When Earth was cool enough, water vapor condensed and rain began to fall. The water cycle began. Over millions of years enough precipitation collected that the first oceans could have formed as early as 4.2 to 4.4 billion years ago. Dissolved minerals carried by stream runoff made the early oceans salty. What geological evidence could there be for the presence of an early ocean? Marine sedimentary rocks can be dated back about 4 billion years. By the Archean, the planet was covered with oceans and the atmosphere was full of water vapor, carbon dioxide, nitrogen, and smaller amounts of other gases. Click image to the left or use the URL below. URL: "
The dwarf planet Ceres was originally considered to be the largest asteroid.,(A) true (B) false,A,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
Pluto is always farther from the sun than Neptune is.,(A) true (B) false,B,"Neptune is shown in Figure 25.29. It is the eighth planet from the Sun. Neptune is so far away you need a telescope to see it from Earth. Neptune is the most distant planet in our solar system. It is nearly 4.5 billion kilometers (2.8 billion miles) from the Sun. One orbit around the Sun takes Neptune 165 Earth years. Scientists guessed Neptunes existence before it was discovered. Uranus did not always appear exactly where it should. They said this was because a planet beyond Uranus was pulling on it. This gravitational pull was affecting its orbit. Neptune was discovered in 1846. It was just where scientists predicted it would be! Due to its blue color, the planet was named Neptune for the Roman god of the sea. Uranus and Neptune are often considered sister planets. They are very similar to each other. Neptune has slightly more mass than Uranus, but it is slightly smaller in size. "
event that occurs when Earth passes through the tail of a comet,(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,G,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
atmosphere of a comet,(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,F,"Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This atmosphere is called a coma. Radiation and particles streaming from the Sun push some of this gas and dust into a long tail. A comets tail always points away from the Sun, no matter which way the comet is moving. Why do you think that is? Figure Gases in the coma and tail of a comet reflect light from the Sun. Comets are very hard to see except when they have comas and tails. That is why they appear only when they are near the Sun. They disappear again as they move back to the outer solar system. The time between one visit from a comet and the next is called the comets period. The first comet whose period was known was Halleys Comet. Its period is 75 years. Halleys Comet last traveled through the inner solar system in 1986. The comet will appear again in 2061. Who will look up at it? "
"small, irregularly shaped, rocky body that orbits the sun",(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,A,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
region from which many comets come,(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,D,"Some comets have periods of 200 years or less. They are called short-period comets. Short-period comets are from a region beyond the orbit of Neptune called the Kuiper Belt. Kuiper is pronounced KI-per, rhyming with viper. The Kuiper Belt is home to comets, asteroids, and at least two dwarf planets. Some comets have periods of thousands or even millions of years. Most long-period comets come from a very distant region of the solar system. This region is called the Oort cloud. The Oort cloud is about 50,000100,000 times the distance from the Sun to Earth. Comets carry materials in from the outer solar system. Comets may have brought water into the early Earth. Other substances could also have come from comets. "
region where most asteroids are located,(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,B,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
small chunk of space rock that burns up as it falls through Earths atmosphere,(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,E,"A meteor, such as in Figure 1.1, is a streak of light across the sky. People call them shooting stars but they are actually small pieces of matter burning up as they enter Earths atmosphere from space. Meteors are called meteoroids before they reach Earths atmosphere. Meteoroids are smaller than asteroids and range from the size of boulders down to the size of tiny sand grains. Still smaller objects are called interplanetary dust. When Earth passes through a cluster of meteoroids, there is a meteor shower. These clusters are often remnants left behind by comet tails. "
"small, icy object that orbits the sun",(A) asteroid (B) asteroid belt (C) comet (D) Kuiper belt (E) meteor (F) coma (G) meteor shower,C,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
Asteroids do not have any of the following except,(A) gravity (B) internal heat (C) an atmosphere (D) geological activity,A,"Asteroids are very small, irregularly shaped, rocky bodies. Asteroids orbit the Sun, but they are more like giant rocks than planets. Since they are small, they do not have enough gravity to become round. They are too small to have an atmosphere. With no internal heat, they are not geologically active. An asteroid can only change due to a collision. A collision may cause the asteroid to break up. It may create craters on the asteroids surface. An asteroid may strike a planet if it comes near enough to be pulled in by its gravity. Figure 25.31 shows a typical asteroid. "
Which of the following statements is true about short-period comets?,(A) They have periods of 200 years or less (B) They come from the asteroid belt (C) The originate in the Oort cloud (D) none of the above,A,"Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This atmosphere is called a coma. Radiation and particles streaming from the Sun push some of this gas and dust into a long tail. A comets tail always points away from the Sun, no matter which way the comet is moving. Why do you think that is? Figure Gases in the coma and tail of a comet reflect light from the Sun. Comets are very hard to see except when they have comas and tails. That is why they appear only when they are near the Sun. They disappear again as they move back to the outer solar system. The time between one visit from a comet and the next is called the comets period. The first comet whose period was known was Halleys Comet. Its period is 75 years. Halleys Comet last traveled through the inner solar system in 1986. The comet will appear again in 2061. Who will look up at it? "
Which of the following is a dwarf planet?,(A) Ceres (B) Haumea (C) Makemake (D) all of the above,D,"For several decades, Pluto was a planet. But new solar system objects were discovered that were just as planet-like as Pluto. Astronomers figured out that they were like planets except for one thing. These objects had not cleared their orbits of smaller objects. They didnt have enough gravity to do so. Astronomers made a category called dwarf planets. There are five dwarf planets in our solar system: Ceres, Pluto, Makemake, Haumea and Eris. Figure 25.36 shows Ceres. Ceres is a rocky body that orbits the Sun and is not a star. It could be an asteroid or a planet. Before 2006, Ceres was thought to be the largest asteroid. Is it an asteroid? Ceres is in the asteroid belt. But it is by far the largest object in the belt. Ceres has such high gravity that it is spherical. Is it a planet? Ceres only has about 1.3% of the mass of the Earths Moon. Its orbit is full of other smaller bodies. Its gravity was not high enough to clear its orbit. Ceres fails the fourth criterion for being a planet. Ceres is now considered a dwarf planet along with Pluto. "
Pluto was once called a planet. Now it has been reclassified as a dwarf planet because,(A) its gravity is too weak to clear its orbit (B) it does not have any moons (C) it consists only of gases (D) its orbit is not elliptical,A,"The reclassification of Pluto to the new category dwarf planet stirred up a great deal of controversy. How the classification of Pluto has evolved is an interesting story in science. From the time it was discovered in 1930 until the early 2000s, Pluto was considered the ninth planet. When astronomers first located Pluto, the telescopes were not as good, so Pluto and its moon, Charon, were seen as one much larger object (Figure 1.1). With better telescopes, astronomers realized that Pluto was much smaller than they had thought. Pluto and its moon, Charon, are actually two objects. Better technology also allowed astronomers to discover many smaller objects like Pluto that orbit the Sun. One of them, Eris, discovered in 2005, is even larger than Pluto. Even when it was considered a planet, Pluto was an oddball. Unlike the other outer planets in the solar system, which are all gas giants, it is small, icy, and rocky. With a diameter of about 2,400 km, it is only about one-fifth the mass of Earths Moon. Plutos orbit is tilted relative to the other planets and is shaped like a long, narrow ellipse. Plutos orbit sometimes even passes inside Neptunes orbit. From what youve read above, do you think Pluto should be called a planet? Why are people hesitant to take away Plutos planetary status? Is Pluto a dwarf planet? Pluto has three moons of its own. The largest, Charon, is big enough that the Pluto-Charon system is sometimes considered to be a double dwarf planet (Figure 1.1). Two smaller moons, Nix and Hydra, were discovered in 2005. But having moons is not enough to make an object a planet. Pluto and the other dwarf planets, besides Ceres, are found orbiting out beyond Neptune. Click image to the left or use the URL below. URL: "
The only dwarf planet located in the asteroid belt is,(A) Eris (B) Ceres (C) Haumea (D) Makemake,B,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
Which dwarf planet is shaped more like an egg than a ball?,(A) Ceres (B) Haumea (C) Eris (D) Pluto,B,"Haumea was named a dwarf planet in 2008. It is an unusual dwarf planet. The body is shaped like an oval! Haumeas longest axis is about the same as Plutos diameter, and its shortest axis is about half as long. The bodys orbit is tilted 28. Haumea is so far from the Sun that it takes 283 years to make one orbit (Figure 25.38). Haumea is the third-brightest Kuiper Belt object. It was named for the Hawaiian goddess of childbirth. Haumea has two moons, Hiiaka and Namaka, the names of the goddess Haumeas daughters. Haumeas odd oval shape is probably caused by its extremely rapid rotation. It rotates in just less than 4 hours! Like other Kuiper belt objects, Haumea is covered by ice. Its density is similar to Earths Moon, at 2.6 3.3 g/cm3 . This means that most of Haumea is rocky. Haumea is part of a collisional family. This is a group of astronomical objects that formed from an impact. This family has Haumea, its two moons, and five more objects. All of these objects are thought to have formed from a collision very early in the formation of the solar system. "
The dwarf planet named Eris,(A) is bigger than Pluto (B) has more moons than Pluto (C) was discovered before Pluto (D) is closer to the sun than Pluto,A,"Eris is the largest known dwarf planet in the solar system. It is 27 percent larger than Pluto (Figure 25.40). Like Pluto and Makemake, Eris is in the Kuiper belt. But Eris is about 3 times farther from the Sun than Pluto. Because of its distance, Eris was not discovered until 2005. Early on, it was thought that Eris might be the tenth planet. Its discovery helped astronomers realize that they needed a new definition of planet. Eris has a small moon, Dysnomia. Its moon orbits Eris once about every 16 days. Astronomers know there may be other dwarf planets far out in the solar system. Look for Quaoar, Varuna and Orcus to be possibly added to the list of dwarf planets in the future. We still have a lot to discover and explore! "
A group of stars that seem from Earth to form the outline of a familiar shape is called a,(A) binary star system (B) constellation (C) solar system (D) galaxy,B,"The biggest groups of stars are called galaxies. A few million to many billions of stars may make up a galaxy. With the unaided eye, every star you can see is part of the Milky Way Galaxy. All the other galaxies are extremely far away. The closest spiral galaxy, the Andromeda Galaxy, shown in Figure 26.8, is 2,500,000 light years away and contains one trillion stars! "
Particle collisions in accelerators simulate,(A) nuclear fission in a black hole (B) fusion of hydrogen into helium (C) the conditions of the birth of the universe (D) all of these,C,"In particle accelerators, subatomic particles are propelled until they have attained almost the same amount of energy as found in the core of a star (Figure 1.3). When these particles collide head-on, new particles are created. This process simulates the nuclear fusion that takes place in the cores of stars. The process also simulates the conditions A diagram of a star like the Sun. that allowed for the first helium atom to be produced from the collision of two hydrogen atoms in the first few minutes of the universe. The SLAC National Accelerator Lab in California can propel particles a straight 2 mi (3.2 km). The CERN Particle Accelerator presented in this video is the worlds largest and most powerful particle accelerator. The accelerator can boost subatomic particles to energy levels that simulate conditions in the stars and in the early history of the universe before stars formed. Click image to the left or use the URL below. URL: "
Constellations appear to move across the sky each night because,(A) all stars have orbits (B) Earth rotates on its axis (C) Earth revolves around the sun (D) constellations are affected by Earths gravity,B,"The stars that make up a constellation appear close to each other from Earth. In reality, they may be very distant from one another. Constellations were important to people, like the Ancient Greeks. People who spent a lot of time outdoors at night, like shepherds, named them and told stories about them. Figure 26.1 shows one of the most easily recognized constellations. The ancient Greeks thought this group of stars looked like a hunter. They named it Orion, after a great hunter in Greek mythology. The constellations stay the same night after night. The patterns of the stars never change. However, each night the constellations move across the sky. They move because Earth is spinning on its axis. The constellations also move with the seasons. This is because Earth revolves around the Sun. Different constellations are up in the winter than in the summer. For example, Orion is high up in the winter sky. In the summer, its only up in the early morning. "
Stars emit energy as,(A) neutrino streams (B) radio waves (C) solar wind (D) electromagnetic radiation,D,"When you look at the sky on a clear night, you can see dozens, perhaps even hundreds, of tiny points of light. Almost every one of these points of light is a star, a giant ball of glowing gas at a very, very high temperature. Stars differ in size, temperature, and age, but they all appear to be made up of the same elements and to behave according to the same principles. "
Which color of star has the highest temperature?,(A) red (B) blue (C) yellow (D) orange,B,Stars shine in many different colors. The color relates to a stars temperature and often its size. 
When our Sun stops fusion it will first become a(n),(A) red giant (B) red supergiant (C) white dwarf (D) blue neutron star,A,"A star like our Sun will become a red giant in its next stage. When a star uses up its hydrogen, it begins to fuse helium atoms. Helium fuses into heavier atoms like carbon. At this time the stars core starts to collapse inward. The stars outer layers spread out and cool. The result is a larger star that is cooler on the surface, and red in color. Eventually a red giant burns up all of the helium in its core. What happens next depends on the stars mass. A star like the Sun stops fusion and shrinks into a white dwarf star. A white dwarf is a hot, white, glowing object about the size of Earth. Eventually, a white dwarf cools down and its light fades out. "
What is the energy source for all stars?,(A) nuclear fusion (B) nuclear fission (C) solar (D) hydrothermal,A,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
Which class of star is our sun?,(A) B (B) F (C) G (D) K,C,"The most common way of classifying stars is by color as shown, in Table 26.1. Each class of star is given a letter, a color, and a range of temperatures. The letters dont match the color names because stars were first grouped as A through O. It wasnt until later that their order was corrected to go by increasing temperature. When you try to remember the order, you can use this phrase: Oh Be A Fine Good Kid, Man. Class O Color Blue Temperature range 30,000 K or more Sample Star An artists depiction of the O class star Zeta Pup- pis. B Blue-white 10,00030,000 K An artists depiction of Rigel, a Class B star. Class A Color White Temperature range 7,50010,000 K Sample Star Sirius A is the brightest star that we see in the night sky. The dot on the right, Sirius B, is a white dwarf. F Yellowish-white 6,0007,500 K There are two F class stars in this image, the super- giant Polaris A and Po- laris B. What we see in the night sky as the single star Polaris, we also known as the North Star. G Yellow 5,5006,000 K Our Sun: the most im- portant G class star in the Universe, at least for hu- mans. Class K M Color Orange Red Temperature range 3,5005,000 K 2,0003,500 K Sample Star Arcturus is a Class K star that looks like the Sun but is much larger. There are two types of Class M stars: red dwarfs and red giants. An artists concept of a red dwarf star. Most stars are red dwarfs. The red supergiant Betel- geuse is seen near Orions belt. The blue star in the lower right is the Class B star Rigel. The surface temperature of most stars is due to its size. Bigger stars produce more energy, so their surfaces are hotter. But some very small stars are very hot. Some very big stars are cool. "
A star forms from a nebula when the temperature is high enough for,(A) a supernova to occur (B) nuclear fusion to start (C) a black hole to collapse (D) heavy elements to form,B,"Stars are born in clouds of gas and dust called nebulas. Our Sun and solar system formed out of a nebula. A nebula is shown in Figure 26.2. In Figure 26.1, the fuzzy area beneath the central three stars contains the Orion nebula. For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star! "
Energy production in a star takes place in the,(A) convective zone (B) core (C) radiative zone (D) corona,B,"Stars are made mostly of hydrogen and helium, which are packed so densely in a star that in the stars center the pressure is great enough to initiate nuclear fusion reactions. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom. Although nuclear fusion reactions require a lot of energy to get started, once they are going they produce enormous amounts of energy (Figure 1.1). In a star, the energy from fusion reactions in the core pushes outward to balance the inward pull of gravity. This energy moves outward through the layers of the star until it finally reaches the stars outer surface. The outer layer of the star glows brightly, sending the energy out into space as electromagnetic radiation, including visible light, heat, ultraviolet light, and radio waves (Figure 1.2). "
Astronomers measure the distance to very distant stars by comparing the stars to our sun. Which factor do they compare?,(A) brightness (B) location (C) parallax (D) color,A,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
A star spends most of its life as a,(A) main sequence star (B) red supergiant (C) white dwarf (D) supernova,A,"We could say that stars are born, change over time, and eventually die. Most stars change in size, color, and class at least once during their lifetime. "
The hottest stars blue-white; the coolest stars are red.,(A) true (B) false,A,Stars shine in many different colors. The color relates to a stars temperature and often its size. 
Stars in a constellation are near each other in space.,(A) true (B) false,B,"Although the stars in a constellation appear close together as we see them in our night sky, they are not at all close together out in space. In the constellation Orion, the stars visible to the naked eye are at distances ranging from just 26 light-years (which is relatively close to Earth) to several thousand light-years away. Click image to the left or use the URL below. URL: "
Our Sun is about half way through its life span.,(A) true (B) false,A,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
A black hole emits dark electromagnetic radiation that we cannot see.,(A) true (B) false,B,"The things we observe in space are objects that emit some type of electromagnetic radiation. However, scientists think that matter that emits light makes up only a small part of the matter in the universe. The rest of the matter, about 80%, is dark matter. Dark matter emits no electromagnetic radiation, so we cant observe it directly. However, astronomers know that dark matter exists because its gravity affects the motion of objects around it. When astronomers measure how spiral galaxies rotate, they find that the outside edges of a galaxy rotate at the same speed as parts closer to the center. This can only be explained if there is a lot more matter in the galaxy than they can see. Gravitational lensing occurs when light is bent from a very distant bright source around a super-massive object (Figure 1.1). To explain strong gravitational lensing, more matter than is observed must be present. With so little to go on, astronomers dont really know much about the nature of dark matter. One possibility is that it could just be ordinary matter that does not emit radiation in objects such as black holes, neutron stars, and brown dwarfs  objects larger than Jupiter but smaller than the smallest stars. But astronomers cannot find enough of these types of objects, which they have named MACHOs (massive astrophyiscal compact halo object), to account for all the dark matter, so they are thought to be only a small part of the total. Another possibility is that the dark matter is very different from the ordinary matter we see. Some appear to be particles that have gravity, but dont otherwise appear to interact with other particles. Scientists call these theoretical particles WIMPs, which stands for Weakly Interactive Massive Particles. Most scientists who study dark matter think that the dark matter in the universe is a combination of MACHOs and some type of exotic matter, such as WIMPs. Researching dark matter is an active area of scientific research, and astronomers knowledge about dark matter is changing rapidly. "
The same constellations appear in a location all year-round.,(A) true (B) false,B,"People of many different cultures, including the Greeks, identified patterns of stars in the sky. We call these patterns constellations. Figure 1.1 shows one of the most easily recognized constellations. Why do the patterns in constellations and in groups or clusters of stars, called asterisms, stay the same night after night? Although the stars move across the sky, they stay in the same patterns. This is because the apparent nightly motion of the stars is actually caused by the rotation of Earth on its axis. The patterns also shift in the sky with the seasons as Earth revolves around the Sun. As a result, people in a particular location can see different constellations in the winter than in the summer. For example, in the Northern Hemisphere Orion is a prominent constellation in the winter sky, but not in the summer sky. This is the annual traverse of the constellations. "
Constellations appear from Earth to move with the seasons.,(A) true (B) false,A,"The stars that make up a constellation appear close to each other from Earth. In reality, they may be very distant from one another. Constellations were important to people, like the Ancient Greeks. People who spent a lot of time outdoors at night, like shepherds, named them and told stories about them. Figure 26.1 shows one of the most easily recognized constellations. The ancient Greeks thought this group of stars looked like a hunter. They named it Orion, after a great hunter in Greek mythology. The constellations stay the same night after night. The patterns of the stars never change. However, each night the constellations move across the sky. They move because Earth is spinning on its axis. The constellations also move with the seasons. This is because Earth revolves around the Sun. Different constellations are up in the winter than in the summer. For example, Orion is high up in the winter sky. In the summer, its only up in the early morning. "
Our sun is the biggest and brightest star in the galaxy.,(A) true (B) false,B,"The Milky Way Galaxy, which is our galaxy. The Milky Way is made of millions of stars along with a lot of gas and dust. It looks different from other galaxies because we are looking at the main disk from within the galaxy. Astronomers estimate that the Milky Way contains 200 to 400 billion stars. "
Stars are made mostly of hydrogen and helium.,(A) true (B) false,A,"Stars are made mostly of hydrogen and helium, which are packed so densely in a star that in the stars center the pressure is great enough to initiate nuclear fusion reactions. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom. Although nuclear fusion reactions require a lot of energy to get started, once they are going they produce enormous amounts of energy (Figure 1.1). In a star, the energy from fusion reactions in the core pushes outward to balance the inward pull of gravity. This energy moves outward through the layers of the star until it finally reaches the stars outer surface. The outer layer of the star glows brightly, sending the energy out into space as electromagnetic radiation, including visible light, heat, ultraviolet light, and radio waves (Figure 1.2). "
The coolest stars are red in color.,(A) true (B) false,A,Stars shine in many different colors. The color relates to a stars temperature and often its size. 
"Once a star forms, it never changes.",(A) true (B) false,B,"We could say that stars are born, change over time, and eventually die. Most stars change in size, color, and class at least once during their lifetime. "
Gravity causes a nebula to become denser at the center.,(A) true (B) false,A,"Stars are born in clouds of gas and dust called nebulas. Our Sun and solar system formed out of a nebula. A nebula is shown in Figure 26.2. In Figure 26.1, the fuzzy area beneath the central three stars contains the Orion nebula. For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star! "
A larger star remains on the main sequence longer than a smaller star.,(A) true (B) false,B,"For most of a stars life, hydrogen atoms fuse to form helium atoms. A star like this is a main sequence star. The hotter a main sequence star is, the brighter it is. A star remains on the main sequence as long as it is fusing hydrogen to form helium. Our Sun has been a main sequence star for about 5 billion years. As a medium-sized star, it will continue to shine for about 5 billion more years. Large stars burn through their supply of hydrogen very quickly. These stars live fast and die young! A very large star may only be on the main sequence for 10 million years. A very small star may be on the main sequence for tens to hundreds of billions of years. "
The next stage our sun will go through is white dwarf.,(A) true (B) false,B,"A star like our Sun will become a red giant in its next stage. When a star uses up its hydrogen, it begins to fuse helium atoms. Helium fuses into heavier atoms like carbon. At this time the stars core starts to collapse inward. The stars outer layers spread out and cool. The result is a larger star that is cooler on the surface, and red in color. Eventually a red giant burns up all of the helium in its core. What happens next depends on the stars mass. A star like the Sun stops fusion and shrinks into a white dwarf star. A white dwarf is a hot, white, glowing object about the size of Earth. Eventually, a white dwarf cools down and its light fades out. "
Betelgeuse is an example of a red supergiant.,(A) true (B) false,A,"A more massive star ends its life in a more dramatic way. Very massive stars become red supergiants, like Betelgeuse. In a red supergiant, fusion does not stop. Lighter atoms fuse into heavier atoms. Eventually iron atoms form. When there is nothing left to fuse, the stars iron core explodes violently. This is called a supernova explosion. The incredible energy released fuses heavy atoms together. Gold, silver, uranium and the other heavy elements can only form in a supernova explosion. A supernova can shine as brightly as an entire galaxy, but only for a short time, as shown in Figure 26.3. "
A black hole is an empty place in space.,(A) true (B) false,B,"After a supernova explosion, the stars core is left over. This material is extremely dense. If the core is less than about four times the mass of the Sun, the star will become a neutron star. A neutron star is shown in Figure 26.4. This type of star is made almost entirely of neutrons. A neutron star has more mass than the Sun, yet it is only a few kilometers in diameter. If the core remaining after a supernova is more than about 5 times the mass of the Sun, the core collapses to become a black hole. Black holes are so dense that not even light can escape their gravity. For that reason, we cant see black holes. How can we know something exists if radiation cant escape it? We know a black hole is there by the effect that it has on objects around it. Also, some radiation leaks out around its edges. A black hole isnt a hole at all. It is the tremendously dense core of a supermassive star. "
giant ball of glowing gas that is very hot,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,G,"When you look at the sky on a clear night, you can see dozens, perhaps even hundreds, of tiny points of light. Almost every one of these points of light is a star, a giant ball of glowing gas at a very, very high temperature. Stars differ in size, temperature, and age, but they all appear to be made up of the same elements and to behave according to the same principles. "
stage of a stars life in which hydrogen atoms fuse to form helium,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,C,"For most of a stars life, hydrogen atoms fuse to form helium atoms. A star like this is a main sequence star. The hotter a main sequence star is, the brighter it is. A star remains on the main sequence as long as it is fusing hydrogen to form helium. Our Sun has been a main sequence star for about 5 billion years. As a medium-sized star, it will continue to shine for about 5 billion more years. Large stars burn through their supply of hydrogen very quickly. These stars live fast and die young! A very large star may only be on the main sequence for 10 million years. A very small star may be on the main sequence for tens to hundreds of billions of years. "
stage of a stars life in which helium atoms fuse to form heavier elements,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,E,"For most of a stars life, hydrogen atoms fuse to form helium atoms. A star like this is a main sequence star. The hotter a main sequence star is, the brighter it is. A star remains on the main sequence as long as it is fusing hydrogen to form helium. Our Sun has been a main sequence star for about 5 billion years. As a medium-sized star, it will continue to shine for about 5 billion more years. Large stars burn through their supply of hydrogen very quickly. These stars live fast and die young! A very large star may only be on the main sequence for 10 million years. A very small star may be on the main sequence for tens to hundreds of billions of years. "
explosion of a red supergiant star,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,F,"A more massive star ends its life in a more dramatic way. Very massive stars become red supergiants, like Betelgeuse. In a red supergiant, fusion does not stop. Lighter atoms fuse into heavier atoms. Eventually iron atoms form. When there is nothing left to fuse, the stars iron core explodes violently. This is called a supernova explosion. The incredible energy released fuses heavy atoms together. Gold, silver, uranium and the other heavy elements can only form in a supernova explosion. A supernova can shine as brightly as an entire galaxy, but only for a short time, as shown in Figure 26.3. "
core of a star that has too much gravity to let light escape,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,B,"After a supernova explosion, the stars core is left over. This material is extremely dense. If the core is less than about four times the mass of the Sun, the star will become a neutron star. A neutron star is shown in Figure 26.4. This type of star is made almost entirely of neutrons. A neutron star has more mass than the Sun, yet it is only a few kilometers in diameter. If the core remaining after a supernova is more than about 5 times the mass of the Sun, the core collapses to become a black hole. Black holes are so dense that not even light can escape their gravity. For that reason, we cant see black holes. How can we know something exists if radiation cant escape it? We know a black hole is there by the effect that it has on objects around it. Also, some radiation leaks out around its edges. A black hole isnt a hole at all. It is the tremendously dense core of a supermassive star. "
cloud of gas and dust from which a star forms,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,D,"Stars are born in clouds of gas and dust called nebulas. Our Sun and solar system formed out of a nebula. A nebula is shown in Figure 26.2. In Figure 26.1, the fuzzy area beneath the central three stars contains the Orion nebula. For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star! "
two stars that orbit each other,(A) binary star system (B) black hole (C) main sequence (D) nebula (E) red giant (F) supernova (G) star,A,"Our solar system has only one star. But many stars are in systems of two or more stars. Two stars that orbit each other are called a binary star system. If more than two stars orbit each other, it is called a multiple star system. Figure 26.5 shows two binary star systems orbiting each other. This creates an unusual quadruple star system. "
Types of star clusters include,(A) open clusters (B) spiral clusters (C) elliptical clusters (D) all of the above,A,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
A galaxy can contain how many stars?,(A) up to 500 (B) up to 30 (C) 000 (D) c up to 10 million (E) d up to many billions,D,"Galaxies are the biggest groups of stars and can contain anywhere from a few million stars to many billions of stars. Every star that is visible in the night sky is part of the Milky Way Galaxy. To the naked eye, the closest major galaxy the Andromeda Galaxy, shown in Figure 1.1  looks like only a dim, fuzzy spot. But that fuzzy spot contains one trillion  1,000,000,000,000  stars! Galaxies are divided into three types according to shape: spiral galaxies, elliptical galaxies, and irregular galaxies. "
Elliptical galaxies contain,(A) a lot of gas and dust (B) mainly young stars (C) mostly red or yellow stars (D) two of the above,C,"Figure 1.3 shows a typical egg-shaped elliptical galaxy. The smallest elliptical galaxies are as small as some globular clusters. Giant elliptical galaxies, on the other hand, can contain over a trillion stars. Elliptical galaxies are reddish to yellowish in color because they contain mostly old stars. Most elliptical galaxies contain very little gas and dust because the gas and dust have already formed into stars. However, some elliptical galaxies, such as the one shown in Figure 1.4, contain lots of dust. Why might some elliptical galaxies contain dust? "
How are irregular galaxies deformed?,(A) from collisions with other galaxies (B) from gravitational pull from a black hole (C) from extremely rapid spin (D) from extremely rapid formation,A,"Look at the galaxy in Figure 26.11. Do you think this is a spiral galaxy or an elliptical galaxy? It doesnt look like either! If a galaxy is not spiral or elliptical, it is an irregular galaxy. Most irregular galaxies have been deformed. This can occur either by the pull of a larger galaxy or by a collision with another galaxy. "
Types of galaxies include,(A) spiral galaxies (B) cluster galaxies (C) circular galaxies (D) globular galaxies,A,"Galaxies are divided into three types, according to shape. There are spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies are a rotating disk of stars and dust. In the center is a dense bulge of material. Several arms spiral out from the center. Spiral galaxies have lots of gas and dust and many young stars. Figure 26.9 shows a spiral galaxy from the side. You can see the disk and central bulge. "
Most elliptical galaxies have very little gas and dust because,(A) they are very young (B) the dust and gas have already formed stars (C) the dust and gas is pulled into supermassive black holes at the center (D) none of these,B,"Figure 1.3 shows a typical egg-shaped elliptical galaxy. The smallest elliptical galaxies are as small as some globular clusters. Giant elliptical galaxies, on the other hand, can contain over a trillion stars. Elliptical galaxies are reddish to yellowish in color because they contain mostly old stars. Most elliptical galaxies contain very little gas and dust because the gas and dust have already formed into stars. However, some elliptical galaxies, such as the one shown in Figure 1.4, contain lots of dust. Why might some elliptical galaxies contain dust? "
Spiral galaxies have,(A) only old stars (B) fewer stars than globular clusters (C) a bulge at the center (D) an elliptical shape,C,"Spiral galaxies spin, so they appear as a rotating disk of stars and dust, with a bulge in the middle, like the Sombrero Galaxy shown in Figure 1.2. Several arms spiral outward in the Pinwheel Galaxy (seen in Figure 1.2) and are appropriately called spiral arms. Spiral galaxies have lots of gas and dust and lots of young stars. The Andromeda Galaxy is a large spiral galaxy similar to the Milky Way. (a) The Sombrero Galaxy is a spiral galaxy that we see from the side so the disk and central bulge are visible. (b) The Pinwheel Galaxy is a spiral galaxy that we see face-on so we can see the spiral arms. Because they contain lots of young stars, spiral arms tend to be blue. "
The stars in an open cluster are mostly,(A) old stars (B) young stars (C) reddish stars (D) two of the above,B,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
Galaxies that do not have a clearly defined shape are called,(A) deformed galaxies (B) irregular galaxies (C) dwarf galaxies (D) open galaxies,B,"Is the galaxy in Figure 1.5 a spiral galaxy or an elliptical galaxy? It is neither one! Galaxies that are not clearly elliptical galaxies or spiral galaxies are irregular galaxies. How might an irregular galaxy form? Most irregular galaxies were once spiral or elliptical galaxies that were then deformed either by gravitational attraction to a larger galaxy or by a collision with another galaxy. This galaxy, called NGC 1427A, has nei- ther a spiral nor an elliptical shape. "
Globular clusters,(A) have a lot of dust in them (B) contain a few hundred to a few thousand stars (C) contain mostly reddish stars (D) all of these,C,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
Scientists estimate that the Milky Way Galaxy contains about,(A) 40 (B) 000 stars (C) b 400 (D) 000 stars (E) c 40 million stars (F) d 400 billion stars,D,"The Milky Way Galaxy is a spiral galaxy that contains about 400 billion stars. Like other spiral galaxies, it has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across. It is about 3,000 light years thick. Most of the galaxys gas, dust, young stars, and open clusters are in the disk. Some astronomers think that there is a gigantic black hole at the center of the galaxy. Figure 26.13 shows what the Milky Way probably looks like from the outside. Our solar system is within one of the spiral arms. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are a little more than halfway out from the center of the Galaxy to the edge, as shown in Figure 26.13. Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. "
Some astronomers think that at the center of our galaxy there is a,(A) neutron star (B) supernova (C) red supergiant (D) black hole,D,"Although it is difficult to know what the shape of the Milky Way Galaxy is because we are inside of it, astronomers have identified it as a typical spiral galaxy containing about 200 billion to 400 billion stars (Figure 1.1). An artists rendition of what astronomers think the Milky Way Galaxy would look like seen from above. The Sun is located approximately where the arrow points. Like other spiral galaxies, our galaxy has a disk, a central bulge, and spiral arms. The disk is about 100,000 light- years across and 3,000 light-years thick. Most of the Galaxys gas, dust, young stars, and open clusters are in the disk. What evidence do astronomers find that lets them know that the Milky Way is a spiral galaxy? 1. The shape of the galaxy as we see it (Figure 1.2). 2. The velocities of stars and gas in the galaxy show a rotational motion. 3. The gases, color, and dust are typical of spiral galaxies. The central bulge is about 12,000 to 16,000 light-years wide and 6,000 to 10,000 light-years thick. The central bulge contains mostly older stars and globular clusters. Some recent evidence suggests the bulge might not be spherical, but is instead shaped like a bar. The bar might be as long as 27,000 light-years long. The disk and bulge are surrounded by a faint, spherical halo, which also contains old stars and globular clusters. Astronomers have discovered that there is a gigantic black hole at the center of the galaxy. The Milky Way Galaxy is a big place. If our solar system were the size of your fist, the Galaxys disk would still be An infrared image of the Milky Way shows the long thin line of stars and the central bulge typical of spiral galaxies. wider than the entire United States! "
type of galaxy that is a rotating disk of stars and dust,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,E,"Galaxies are divided into three types, according to shape. There are spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies are a rotating disk of stars and dust. In the center is a dense bulge of material. Several arms spiral out from the center. Spiral galaxies have lots of gas and dust and many young stars. Figure 26.9 shows a spiral galaxy from the side. You can see the disk and central bulge. "
star cluster containing up to a few thousand stars,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,D,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
type of galaxy that is oval in shape,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,A,Figure 26.10 shows a typical elliptical galaxy. Elliptical galaxies are oval in shape. The smallest are called dwarf elliptical galaxies. Look back at the image of the Andromeda Galaxy. It has two dwarf elliptical galaxies as its companions. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Giant elliptical galaxies contain over a trillion stars. Elliptical galaxies are red to yellow in color because they contain mostly old stars. Most contain very little gas and dust because the material has already formed into stars. 
The Milky Way appears as a band of light across the night sky.,(A) true (B) false,A,"If you get away from city lights and look up in the sky on a very clear night, you will see something spectacular. A band of milky light stretches across the sky, as in Figure 26.12. This band is the disk of the Milky Way Galaxy. This is the galaxy where we all live. The Milky Way Galaxy looks different to us than other galaxies because our view is from inside of it! "
group of stars that is smaller than a galaxy,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,F,"Galaxies are the biggest groups of stars and can contain anywhere from a few million stars to many billions of stars. Every star that is visible in the night sky is part of the Milky Way Galaxy. To the naked eye, the closest major galaxy the Andromeda Galaxy, shown in Figure 1.1  looks like only a dim, fuzzy spot. But that fuzzy spot contains one trillion  1,000,000,000,000  stars! Galaxies are divided into three types according to shape: spiral galaxies, elliptical galaxies, and irregular galaxies. "
Most of the galaxies we see from Earth are dwarf galaxies.,(A) true (B) false,B,"Dwarf galaxies are small galaxies containing only a few million to a few billion stars. Dwarf galaxies are the most common type in the universe. However, because they are relatively small and dim, we dont see as many dwarf galaxies from Earth. Most dwarf galaxies are irregular in shape. However, there are also dwarf elliptical galaxies and dwarf spiral galaxies. Look back at the picture of the elliptical galaxy. In the figure, you can see two dwarf elliptical galaxies that are companions to the Andromeda Galaxy. One is a bright sphere to the left of center, and the other is a long ellipse below and to the right of center. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
very large group of stars that are held together by gravity,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,G,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
star cluster containing up to tens of thousands of stars,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,B,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
Elliptical galaxies have mostly younger blue stars.,(A) true (B) false,B,Figure 26.10 shows a typical elliptical galaxy. Elliptical galaxies are oval in shape. The smallest are called dwarf elliptical galaxies. Look back at the image of the Andromeda Galaxy. It has two dwarf elliptical galaxies as its companions. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Giant elliptical galaxies contain over a trillion stars. Elliptical galaxies are red to yellow in color because they contain mostly old stars. Most contain very little gas and dust because the material has already formed into stars. 
type of galaxy that is neither spiral nor elliptical in shape,(A) elliptical galaxy (B) globular cluster (C) irregular galaxy (D) open cluster (E) spiral galaxy (F) star cluster (G) galaxy,C,"Is the galaxy in Figure 1.5 a spiral galaxy or an elliptical galaxy? It is neither one! Galaxies that are not clearly elliptical galaxies or spiral galaxies are irregular galaxies. How might an irregular galaxy form? Most irregular galaxies were once spiral or elliptical galaxies that were then deformed either by gravitational attraction to a larger galaxy or by a collision with another galaxy. This galaxy, called NGC 1427A, has nei- ther a spiral nor an elliptical shape. "
Every star that you see without a telescope is in the Milky Way Galaxy.,(A) true (B) false,A,"If you get away from city lights and look up in the sky on a very clear night, you will see something spectacular. A band of milky light stretches across the sky, as in Figure 26.12. This band is the disk of the Milky Way Galaxy. This is the galaxy where we all live. The Milky Way Galaxy looks different to us than other galaxies because our view is from inside of it! "
Our solar system is slowly spinning around our galaxy.,(A) true (B) false,A,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
There are billions of galaxies in the universe.,(A) true (B) false,A,"The biggest groups of stars are called galaxies. A few million to many billions of stars may make up a galaxy. With the unaided eye, every star you can see is part of the Milky Way Galaxy. All the other galaxies are extremely far away. The closest spiral galaxy, the Andromeda Galaxy, shown in Figure 26.8, is 2,500,000 light years away and contains one trillion stars! "
A star cluster may contain one or more galaxies.,(A) true (B) false,B,"Galaxies are the biggest groups of stars and can contain anywhere from a few million stars to many billions of stars. Every star that is visible in the night sky is part of the Milky Way Galaxy. To the naked eye, the closest major galaxy the Andromeda Galaxy, shown in Figure 1.1  looks like only a dim, fuzzy spot. But that fuzzy spot contains one trillion  1,000,000,000,000  stars! Galaxies are divided into three types according to shape: spiral galaxies, elliptical galaxies, and irregular galaxies. "
Open star clusters contain more stars than globular star clusters.,(A) true (B) false,B,"Star clusters are groups of stars smaller than a galaxy. There are two main types, open clusters and globular clusters. Open clusters are groups of up to a few thousand stars held together by gravity. The Jewel Box, shown in Figure an open cluster are young stars that all formed from the same nebula. Globular clusters are groups of tens to hundreds of thousands of stars held tightly together by gravity. Globular clusters have a definite, spherical shape. They contain mostly old, reddish stars. Near the center of a globular cluster, the stars are closer together. Figure 26.7 shows a globular cluster. The heart of the globular cluster M13 has hundreds of thousands of stars. M13 is 145 light years in diameter. The cluster contains red and blue giant stars. "
Galaxies are divided into types based on size.,(A) true (B) false,B,"Galaxies are divided into three types, according to shape. There are spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies are a rotating disk of stars and dust. In the center is a dense bulge of material. Several arms spiral out from the center. Spiral galaxies have lots of gas and dust and many young stars. Figure 26.9 shows a spiral galaxy from the side. You can see the disk and central bulge. "
Spiral galaxies are generally older than elliptical galaxies.,(A) true (B) false,B,"Galaxies are divided into three types, according to shape. There are spiral galaxies, elliptical galaxies, and irregular galaxies. Spiral galaxies are a rotating disk of stars and dust. In the center is a dense bulge of material. Several arms spiral out from the center. Spiral galaxies have lots of gas and dust and many young stars. Figure 26.9 shows a spiral galaxy from the side. You can see the disk and central bulge. "
Dwarf galaxies are often found near larger galaxies.,(A) true (B) false,A,"Dwarf galaxies are small galaxies containing only a few million to a few billion stars. Dwarf galaxies are the most common type in the universe. However, because they are relatively small and dim, we dont see as many dwarf galaxies from Earth. Most dwarf galaxies are irregular in shape. However, there are also dwarf elliptical galaxies and dwarf spiral galaxies. Look back at the picture of the elliptical galaxy. In the figure, you can see two dwarf elliptical galaxies that are companions to the Andromeda Galaxy. One is a bright sphere to the left of center, and the other is a long ellipse below and to the right of center. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Some galaxies contain over a trillion stars.,(A) true (B) false,A,"The biggest groups of stars are called galaxies. A few million to many billions of stars may make up a galaxy. With the unaided eye, every star you can see is part of the Milky Way Galaxy. All the other galaxies are extremely far away. The closest spiral galaxy, the Andromeda Galaxy, shown in Figure 26.8, is 2,500,000 light years away and contains one trillion stars! "
Our solar system is within one of the spiral arms of our galaxy.,(A) true (B) false,A,"The Milky Way Galaxy is a spiral galaxy that contains about 400 billion stars. Like other spiral galaxies, it has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across. It is about 3,000 light years thick. Most of the galaxys gas, dust, young stars, and open clusters are in the disk. Some astronomers think that there is a gigantic black hole at the center of the galaxy. Figure 26.13 shows what the Milky Way probably looks like from the outside. Our solar system is within one of the spiral arms. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are a little more than halfway out from the center of the Galaxy to the edge, as shown in Figure 26.13. Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. "
Our solar system orbits the central disk of our galaxy.,(A) true (B) false,A,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
"From Earth, our galaxy looks like a giant spiral.",(A) true (B) false,B,"Spiral galaxies spin, so they appear as a rotating disk of stars and dust, with a bulge in the middle, like the Sombrero Galaxy shown in Figure 1.2. Several arms spiral outward in the Pinwheel Galaxy (seen in Figure 1.2) and are appropriately called spiral arms. Spiral galaxies have lots of gas and dust and lots of young stars. The Andromeda Galaxy is a large spiral galaxy similar to the Milky Way. (a) The Sombrero Galaxy is a spiral galaxy that we see from the side so the disk and central bulge are visible. (b) The Pinwheel Galaxy is a spiral galaxy that we see face-on so we can see the spiral arms. Because they contain lots of young stars, spiral arms tend to be blue. "
particle of rock or mineral,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,D,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
How many major rock types are in the rock cycle?,(A) 3 (B) 4 (C) 5 (D) 7,A,"The rock cycle, illustrated in Figure 1.1, depicts how the three major rock types - igneous, sedimentary, and meta- morphic - convert from one to another. Arrows connecting the rock types represent the processes that accomplish these changes. Rocks change as a result of natural processes that are taking place all the time. Most changes happen very slowly. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Even at the surface, we may not notice the changes. The rock cycle has no beginning or end. "
any mixture of minerals in the solid state,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,C,"Minerals are ""crystalline"" solids. A crystal is a solid in which the atoms are arranged in a regular, repeating pattern. Notice that in Figure 1.1 the green and purple spheres, representing sodium and chlorine, form a repeating pattern. In this case, they alternate in all directions. Sodium ions (purple balls) bond with chlo- ride ions (green balls) to make table salt (halite). All of the grains of salt that are in a salt shaker have this crystalline structure. "
Each type of rock has a particular,(A) color (B) size (C) set of minerals (D) shape,C,1. Distinctive rock formations may be recognizable across large regions (Figure 1.1). 
type of rock that forms when sediments are compacted and cemented together,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,G,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
The texture of a rock is describes what feature of the mineral grains?,(A) size (B) shape (C) arrangement (D) all of the above,D,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
"Two rocks have the same minerals, but of very different sizes. Which statement is true?",(A) One rock has more eroded fragments than the other (B) The minerals cooled at different rates from a magma (C) The rocks have different compositions (D) One rock is igneous and one rock is metamorphic,B,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
type of rock that forms when existing rock is subjected to high heat and pressure,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
type of rock that forms when magma or lava cools,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,E,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
A rock that was once a different rock with a different mineral composition and/or texture is a(n),(A) igneous rock (B) sedimentary rock (C) metamorphic rock (D) hard rock,C,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
continuous series of processes by which rocks change from one type to another,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,A,"Several processes can turn one type of rock into another type of rock. The key processes of the rock cycle are crystallization, erosion and sedimentation, and metamorphism. "
process in which a rock changes to a different type of rock due to extreme heat and pressure,(A) rock cycle (B) metamorphic rock (C) rock (D) sediment (E) igneous rock (F) metamorphism (G) sedimentary rock,F,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Major types of rocks include,(A) sedimentary rocks (B) metamorphic rocks (C) igneous rocks (D) all of the above,D,"Rocks are classified into three major groups according to how they form. These three types are described in more detail in other concepts in this chapter, but here is a summary. The Rock Cycle. Igneous rocks form from the cooling and hardening of molten magma in many different environments. The chemical composition of the magma and the rate at which it cools determine what rock forms. Igneous rocks can cool slowly beneath the surface or rapidly at the surface. These rocks are identified by their composition and texture. More than 700 different types of igneous rocks are known. Sedimentary rocks form by the compaction and cementing together of sediments, broken pieces of rock-like gravel, sand, silt, or clay. Those sediments can be formed from the weathering and erosion of preexisting rocks. Sedimentary rocks also include chemical precipitates, the solid materials left behind after a liquid evaporates. Metamorphic rocks form when the minerals in an existing rock are changed by heat or pressure below the surface. Click image to the left or use the URL below. URL: "
Which rocks may form on Earths surface?,(A) sedimentary rocks (B) metamorphic rocks (C) igneous rocks (D) two of the above,D,Remember that the most common minerals in Earths crust are the silicate minerals. Many silicate minerals form in igneous or metamorphic rocks. The minerals that form at the highest temperatures and pressures are the least stable at the surface. Clay is stable at the surface and chemical weathering converts many minerals to clay (Figure 1.1). There are many types of chemical weathering because there are many agents of chemical weathering. Deforestation in Brazil reveals the under- lying clay-rich soil. 
Weathering and erosion occur because of the actions of,(A) ice (B) wind (C) water (D) all of the above,D,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
"As magma cools, all of the mineral grains form at the same temperature.",(A) true (B) false,B,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
The process in which sedimentary rocks form begins with,(A) erosion (B) deposition (C) weathering (D) compaction,C,"Most sedimentary rocks form from sediments. Sediments are small pieces of other rocks, like pebbles, sand, silt, and clay. Sedimentary rocks may include fossils. Fossils are materials left behind by once-living organisms. Fossils can be pieces of the organism, like bones. They can also be traces of the organism, like footprints. Most often, sediments settle out of water (Figure 4.13). For example, rivers carry lots of sediment. Where the water slows, it dumps these sediments along its banks, into lakes and the ocean. When sediments settle out of water, they form horizontal layers. A layer of sediment is deposited. Then the next layer is deposited on top of that layer. So each layer in a sedimentary rock is younger than the layer under it. It is older than the layer over it. Sediments are deposited in many different types of environments. Beaches and deserts collect large deposits of sand. Sediments also continuously wind up at the bottom of the ocean and in lakes, ponds, rivers, marshes, and swamps. Avalanches produce large piles of sediment. The environment where the sediments are deposited determines the type of sedimentary rock that can form. "
Metamorphism may change the chemical composition of a rock.,(A) true (B) false,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
The rock called limestone forms when shells of sea organisms settle to the bottom of the water and gradually become pressed and cemented together. Which type of rock is limestone?,(A) igneous (B) metamorphic (C) sedimentary (D) none of the above,C,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
"If limestone is buried under the ground and placed under pressure until it becomes extremely hot, it changes to marble. The process in which marble forms from limestone is",(A) melting (B) compression (C) sedimentation (D) metamorphism,D,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Only one type of mineral can be present in a metamorphic rock.,(A) true (B) false,B,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
Which process is involved when a sedimentary rock changes to an igneous rock?,(A) metamorphism (B) melting (C) sedimentation (D) weathering,B,"Any type of rock can change and become a new type of rock. Magma can cool and crystallize. Existing rocks can be weathered and eroded to form sediments. Rock can change by heat or pressure deep in Earths crust. There are three main processes that can change rock: Cooling and forming crystals. Deep within the Earth, temperatures can get hot enough to melt rock. This molten material is called magma. As it cools, crystals grow, forming an igneous rock. The crystals will grow larger if the magma cools slowly, as it does if it remains deep within the Earth. If the magma cools quickly, the crystals will be very small. Weathering and erosion. Water, wind, ice, and even plants and animals all act to wear down rocks. Over time they can break larger rocks into smaller pieces called sediments. Moving water, wind, and glaciers then carry these pieces from one place to another. The sediments are eventually dropped, or deposited, somewhere. The sediments may then be compacted and cemented together. This forms a sedimentary rock. This whole process can take hundreds or thousands of years. Metamorphism. This long word means to change form. A rock undergoes metamorphism if it is exposed to extreme heat and pressure within the crust. With metamorphism, the rock does not melt all the way. The rock changes due to heat and pressure. A metamorphic rock may have a new mineral composition and/or texture. An interactive rock cycle diagram can be found here:  The rock cycle really has no beginning or end. It just continues. The processes involved in the rock cycle take place over hundreds, thousands, or even millions of years. Even though for us rocks are solid and unchanging, they slowly change all the time. "
Rocks can be studied through a microscope,(A) true (B) false,A,"Microscopes, tools that you may get to use in your class, are some of the most important tools in biology ( Figure Microscopy is the study of small objects using microscopes. Look at your fingertips. Before microscopes were invented in 1595, the smallest things you could see on yourself were the tiny lines in your skin. But what else is hidden in your skin? "
A metamorphic rock must have a different mineral composition than its parent rock,(A) true (B) false,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
"When a rock changes from one type to another, it usually happens very quickly.",(A) true (B) false,B,"The rock cycle, illustrated in Figure 1.1, depicts how the three major rock types - igneous, sedimentary, and meta- morphic - convert from one to another. Arrows connecting the rock types represent the processes that accomplish these changes. Rocks change as a result of natural processes that are taking place all the time. Most changes happen very slowly. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Even at the surface, we may not notice the changes. The rock cycle has no beginning or end. "
One type of rock can change to any other type of rock.,(A) true (B) false,A,"Any type of rock can change and become a new type of rock. Magma can cool and crystallize. Existing rocks can be weathered and eroded to form sediments. Rock can change by heat or pressure deep in Earths crust. There are three main processes that can change rock: Cooling and forming crystals. Deep within the Earth, temperatures can get hot enough to melt rock. This molten material is called magma. As it cools, crystals grow, forming an igneous rock. The crystals will grow larger if the magma cools slowly, as it does if it remains deep within the Earth. If the magma cools quickly, the crystals will be very small. Weathering and erosion. Water, wind, ice, and even plants and animals all act to wear down rocks. Over time they can break larger rocks into smaller pieces called sediments. Moving water, wind, and glaciers then carry these pieces from one place to another. The sediments are eventually dropped, or deposited, somewhere. The sediments may then be compacted and cemented together. This forms a sedimentary rock. This whole process can take hundreds or thousands of years. Metamorphism. This long word means to change form. A rock undergoes metamorphism if it is exposed to extreme heat and pressure within the crust. With metamorphism, the rock does not melt all the way. The rock changes due to heat and pressure. A metamorphic rock may have a new mineral composition and/or texture. An interactive rock cycle diagram can be found here:  The rock cycle really has no beginning or end. It just continues. The processes involved in the rock cycle take place over hundreds, thousands, or even millions of years. Even though for us rocks are solid and unchanging, they slowly change all the time. "
All the processes of the rock cycle take place underground.,(A) true (B) false,B,"The rock cycle, illustrated in Figure 1.1, depicts how the three major rock types - igneous, sedimentary, and meta- morphic - convert from one to another. Arrows connecting the rock types represent the processes that accomplish these changes. Rocks change as a result of natural processes that are taking place all the time. Most changes happen very slowly. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Even at the surface, we may not notice the changes. The rock cycle has no beginning or end. "
"To see the minerals in rock, you always need to use a microscope.",(A) true (B) false,B,"Microscopes, tools that you may get to use in your class, are some of the most important tools in biology ( Figure Microscopy is the study of small objects using microscopes. Look at your fingertips. Before microscopes were invented in 1595, the smallest things you could see on yourself were the tiny lines in your skin. But what else is hidden in your skin? "
Rocks are named for the minerals they contain and how the minerals came together.,(A) true (B) false,A,"All rocks on Earth change, but these changes usually happen very slowly. Some changes happen below Earths surface. Some changes happen above ground. These changes are all part of the rock cycle. The rock cycle describes each of the main types of rocks, how they form and how they change. Figure 4.1 shows how the three main rock types are related to each other. The arrows within the circle show how one type of rock may change to rock of another type. For example, igneous rock may break down into small pieces of sediment and become sedimentary rock. Igneous rock may be buried within the Earth and become metamorphic rock. Igneous rock may also change back to molten material and re-cool into a new igneous rock. Rocks are made of minerals. The minerals may be so tiny that you can only see them with a microscope. The minerals may be really large. A rock may be made of only one type of mineral. More often rocks are made of a mixture of different minerals. Rocks are named for the combinations of minerals they are made of and the ways those minerals came together. Remember that different minerals form under different environmental conditions. So the minerals in a rock contain clues about the conditions in which the rock formed (Figure 4.2). "
A rock formed from pieces of gravel and sand would be classified as an igneous rock.,(A) true (B) false,B,"Geologists group rocks based on how they were formed. The three main kinds of rocks are: 1. Igneous rocks form when magma cools below Earths surface or lava cools at the surface (Figure 4.3). 2. Sedimentary rocks form when sediments are compacted and cemented together (Figure 4.4). These sediments may be gravel, sand, silt or clay. Sedimentary rocks often have pieces of other rocks in them. Some sedimentary rocks form the solid minerals left behind after a liquid evaporates. 3. Metamorphic rocks form when an existing rock is changed by heat or pressure. The minerals in the rock change but do not melt (Figure 4.5). The rock experiences these changes within the Earth. Rocks can be changed from one type to another, and the rock cycle describes how this happens. "
A rock resulting from the formation of mineral crystals would be classified as a sedimentary rock.,(A) true (B) false,B,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
Sedimentary rocks include sandstone and shale.,(A) true (B) false,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
Plants and animals can act to wear down rocks.,(A) true (B) false,A,"Now that you know what mechanical weathering is, can you think of other ways it could happen? Plants and animals can do the work of mechanical weathering (Figure 1.3). This could happen slowly as a plants roots grow into a crack or fracture in rock and gradually grow larger, wedging open the crack. Burrowing animals can also break apart rock as they dig for food or to make living spaces for themselves. "
Metamorphism may change a rocks mineral composition.,(A) true (B) false,A,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Which term describes igneous rocks that crystallize above the crust,(A) extrusive (B) intrusive (C) magma (D) lava,A,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
"Which mineral is the most common in a dark-colored, mafic igneous rock?",(A) diamond (B) quartz (C) pyroxene (D) olivine,D,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
The color of minerals in an igneous rock is determined by,(A) the composition of the magma (B) the length of time it took the magma to cool (C) whether it cooled from a lava or a magma (D) none of the above,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
An igneous rock with large crystals cooled,(A) rapidly from a lava (B) rapidly beneath the surface (C) slowly from a magma (D) unknown,C,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
Extrusive igneous rocks,(A) are common because large mountain ranges are made entirely of basalt (B) are common because the seafloor is made up of basalt (C) are rare because not much rock melts to produce lava (D) are rare because much more magma cools intrusively,B,Extrusive igneous rocks cool at the surface. Volcanoes are one type of feature that forms from extrusive rocks. Several other interesting landforms are also extrusive features. Intrusive igneous rocks cool below the surface. These rocks do not always remain hidden. Rocks that formed in the crust are exposed when the rock and sediment that covers them is eroded away. 
The layer of Earth called the mantle is made entirely of igneous rock.,(A) true (B) false,A,"The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. "
Rock on the ocean floor is intrusive igneous rock.,(A) true (B) false,B,"Oceanic crust is composed of mafic magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro (Figure 1.1). Gabbro from ocean crust. The gabbro is deformed because of intense faulting at the eruption site. Sediments, primarily mud and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore, where it comes off the continents in rivers and on wind currents. The oceanic crust is relatively thin and lies above the mantle. The cross section of oceanic crust in the Figure 1.2 shows the layers that grade from sediments at the top to extrusive basalt lava, to the sheeted dikes that feed lava to the surface, to deeper intrusive gabbro, and finally to the mantle. "
The Sierra Nevada Mountains in California are composed mainly of granite.,(A) true (B) false,A,"Placer minerals collect in stream gravels. They can be found in modern rivers or ancient riverbeds. California was nicknamed the Golden State. This can be traced back to the discovery of placer gold in 1848. The amount of placer gold brought in miners from around the world. The gold formed in rocks in the Sierra Nevada Mountains. The rocks also contained other valuable minerals. The gold weathered out of the hard rock. It washed downstream and then settled in gravel deposits along the river. Currently, California has active gold and silver mines. California also has mines for non-metal minerals. For example, sand and gravel are mined for construction. "
A basalt looks light colored partly because its crystals are too small to see.,(A) true (B) false,B,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
"When melted rock cools more slowly, it forms larger crystals.",(A) true (B) false,A,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
Volcanic rock may have so many gas bubbles that it can float on water.,(A) true (B) false,A,"Gases may be able to escape a volcano before magma reaches the surface. Scientists measure gas emissions in vents on or around the volcano. Gases, such as sulfur dioxide (SO2 ), carbon dioxide (CO2 ), hydrochloric acid (HCl), and even water vapor can be measured at the site (Figure 1.1) or, in some cases, from a distance using satellites. The amounts of gases and their ratios are calculated to help predict eruptions. Scientists monitoring gas emissions at Mount St. Helens. "
Melted rock cools more quickly underground than on Earths surface.,(A) true (B) false,B,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
Obsidian forms when magma cools and forms crystals.,(A) true (B) false,B,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
Granite and rhyolite are high silica rocks.,(A) true (B) false,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
Pumice contains holes because gas bubbles were trapped in lava as it cooled.,(A) true (B) false,A,"The way lava flows depends on what it is made of. Thick lava doesnt flow easily. It may block the vent of a volcano. If the lava traps a lot of gas, the pressure builds up. After the pressure becomes greater and greater, the volcano finally explodes. Ash and pyroclasts shoot up into the air. Pumice, with small holes in solid rock, shows where gas bubbles were when the rock was still molten. Fluid lava flows down mountainsides. The rock that the flow becomes depends on which type of lava it is and where it cools. The three types of flows are aa, pahoehoe, and pillow lava. Aa Lava Aa lava is the thickest of the non-explosive lavas. Aa forms a thick and brittle crust, which is torn into rough, rubbly pieces. The solidified surface is angular, jagged and sharp. Aa can spread over large areas as the lava continues to flow underneath. Pahoehoe Lava Pahoehoe lava is thinner than aa, and flows more readily. Its surface looks more wrinkly and smooth. Pahoehoe lava flows in a series of lobes that form strange twisted shapes and natural rock sculptures (Figure 8.9). Pahoehoe lava can form lava tubes. The outer layer of the lava flow cools and solidifies. The inner part of the flow remains fluid. The fluid lava flows through and leaves behind a tube (Figure 8.10). Pillow Lava Pillow lava is created from lava that enters the water. The volcanic vent may be underwater. The lava may flow over land and enter the water (Figure 8.11). Once in the water, the lava cools very quickly. The lava forms round rocks that resemble pillows. Pillow lava is particularly common along mid-ocean ridges. "
Mountain ranges can be made mainly of igneous rocks.,(A) true (B) false,A,"Igneous rocks are called intrusive when they cool and solidify beneath the surface. Intrusive rocks form plutons and so are also called plutonic. A pluton is an igneous intrusive rock body that has cooled in the crust. When magma cools within the Earth, the cooling proceeds slowly. Slow cooling allows time for large crystals to form, so intrusive igneous rocks have visible crystals. Granite is the most common intrusive igneous rock (see Figure 1.1 for an example). Igneous rocks make up most of the rocks on Earth. Most igneous rocks are buried below the surface and covered with sedimentary rock, or are buried beneath the ocean water. In some places, geological processes have brought Granite is made of four minerals, all visible to the naked eye: feldspar (white), quartz (translucent), hornblende (black), and bi- otite (black, platy). igneous rocks to the surface. Figure 1.2 shows a landscape in Californias Sierra Nevada Mountains made of granite that has been raised to create mountains. Californias Sierra Nevada Mountains are intrusive igneous rock exposed at Earths surface. "
Igneous rock is too hard to be used for art works.,(A) true (B) false,B,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
Basalt crystals are too small to see with the unaided eye.,(A) true (B) false,A,"The Suns surface features are quite visible, but only with special equipment. For example, sunspots are only visible with special light-filtering lenses. "
The combination of minerals in igneous rocks is determined by the composition of the magma or lava.,(A) true (B) false,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
Both porphyry and diorite are extrusive igneous rocks.,(A) true (B) false,A,Extrusive igneous rocks cool at the surface. Volcanoes are one type of feature that forms from extrusive rocks. Several other interesting landforms are also extrusive features. Intrusive igneous rocks cool below the surface. These rocks do not always remain hidden. Rocks that formed in the crust are exposed when the rock and sediment that covers them is eroded away. 
any rock that forms when magma or lava cools,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,C,"Imagine a rock that becomes so hot it melts. Many minerals start out in liquids that are hot enough to melt rocks. Magma is melted rock inside Earth, a molten mixture of substances that can be hotter than 1,000 C. Magma cools slowly inside Earth, which gives mineral crystals time to grow large enough to be seen clearly (Figure 1.1). Granite is rock that forms from slowly cooled magma, containing the minerals quartz (clear), plagioclase feldspar (shiny white), potassium feldspar (pink), and bi- otite (black). When magma erupts onto Earths surface, it is called lava. Lava cools much more rapidly than magma. Crystals do not have time to form and are very small. The chemical composition between minerals that form rapidly or slowly is often the same, only their size differs. Existing rocks may be heated enough so that the molecules are released from their structure and can move around. The molecules may match up with different molecules to form new minerals as the rock cools. This occurs during metamorphism, which will be discussed in the ""Metamorphic Rocks"" concept. "
most common intrusive igneous rock,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,G,"Igneous rocks are called intrusive when they cool and solidify beneath the surface. Intrusive rocks form plutons and so are also called plutonic. A pluton is an igneous intrusive rock body that has cooled in the crust. When magma cools within the Earth, the cooling proceeds slowly. Slow cooling allows time for large crystals to form, so intrusive igneous rocks have visible crystals. Granite is the most common intrusive igneous rock (see Figure 1.1 for an example). Igneous rocks make up most of the rocks on Earth. Most igneous rocks are buried below the surface and covered with sedimentary rock, or are buried beneath the ocean water. In some places, geological processes have brought Granite is made of four minerals, all visible to the naked eye: feldspar (white), quartz (translucent), hornblende (black), and bi- otite (black, platy). igneous rocks to the surface. Figure 1.2 shows a landscape in Californias Sierra Nevada Mountains made of granite that has been raised to create mountains. Californias Sierra Nevada Mountains are intrusive igneous rock exposed at Earths surface. "
type of igneous rock that forms on Earths surface,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,A,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
igneous rock that is full of holes,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,F,"Underground water can be heated by magma. The hot water moves through cracks below Earths surface. Hot water can hold more dissolved particles than cold water. The hot, salty solution has chemical reactions with the rocks around it. The water picks up more dissolved particles. As it flows through open spaces in rocks, the water deposits solid minerals. When a mineral fills cracks in rocks, the deposits are called veins. Figure 3.20 shows a white quartz vein. When the minerals are deposited in open spaces, large crystals grow. These rocks are called geodes. Figure 3.20 shows a geode that was formed when amethyst crystals grew in an open space in a rock. "
most common extrusive igneous rock,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,B,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
type of igneous rock that forms beneath Earths surface,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,D,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
glass-like igneous rock that does not contain mineral crystals,(A) extrusive igneous rock (B) basalt (C) igneous rock (D) intrusive igneous rock (E) obsidian (F) pumice (G) granite,E,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
Igneous rocks are classified by,(A) the size of their crystals (B) the type of sediments they contain (C) their mineral composition (D) two of the above,D,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
How many different kinds of igneous rocks are there?,(A) only 7 (B) about 70 (C) more than 700 (D) between 70 and 100,C,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
Granite is used to make,(A) countertops (B) buildings (C) statues (D) all of the above,D,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
How is pumice used?,(A) to smooth rough skin (B) to stonewash jeans (C) to make vases (D) two of the above,D,"The hard skeleton of echinoderms is used as a source of lime by farmers in some areas where limestone is unavailable. Lime is added to the soil to allow plants to take up more nutrients. About 4,000 tons of the animals are used each year for this purpose. "
The rock that makes up the ocean floor is,(A) granite (B) basalt (C) diorite (D) peridotite,B,"Oceanic crust is composed of mafic magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro (Figure 1.1). Gabbro from ocean crust. The gabbro is deformed because of intense faulting at the eruption site. Sediments, primarily mud and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore, where it comes off the continents in rivers and on wind currents. The oceanic crust is relatively thin and lies above the mantle. The cross section of oceanic crust in the Figure 1.2 shows the layers that grade from sediments at the top to extrusive basalt lava, to the sheeted dikes that feed lava to the surface, to deeper intrusive gabbro, and finally to the mantle. "
One property of pumice is,(A) a smooth glassy texture (B) very large crystals (C) the ability to float on water (D) none of the above,C,"Some minerals have other unique properties, some of which are listed in Table 1.3. Can you name a unique property that would allow you to instantly identify a mineral thats been described quite a bit in this concept? (Hint: It is most likely found on your dinner table.) Chrysotile has splintery fracture. Property Fluorescence Magnetism Radioactivity Reactivity Smell Taste Description Mineral glows under ultraviolet light Mineral is attracted to a magnet Mineral gives off radiation that can be measured with Geiger counter Bubbles form when mineral is ex- posed to a weak acid Some minerals have a distinctive smell Some minerals taste salty Example of Mineral Fluorite Magnetite Uraninite Calcite Sulfur (smells like rotten eggs) Halite "
Many mountain ranges are made of,(A) granite (B) gabbro (C) andesite (D) komatite,A,Continent-continent convergence creates some of the worlds largest mountains ranges. The Himalayas (Figure are the remnants of a larger mountain range. This range formed from continent-continent collisions in the time of Pangaea. 
Types of sediments that may make up sedimentary rocks include,(A) pebbles (B) silt (C) clay (D) all of the above,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
What are solid particles that have been deposited on the Earths surface called?,(A) lava (B) sediments (C) quartz (D) soils,B,"Weathering wears rocks at the Earths surface down into smaller pieces. The small fragments are called sediments. Running water, ice, and gravity all transport these sediments from one place to another by erosion. During sedimen- tation, the sediments are laid down or deposited. In order to form a sedimentary rock, the accumulated sediment must become compacted and cemented together. "
A river deposits sediments when the water,(A) slows down (B) enters a lake (C) reaches the ocean (D) all of the above,D,"When a stream or river slows down, it starts dropping its sediments. Larger sediments are dropped in steep areas, but smaller sediments can still be carried. Smaller sediments are dropped as the slope becomes less steep. Alluvial Fans In arid regions, a mountain stream may flow onto flatter land. The stream comes to a stop rapidly. The deposits form an alluvial fan, like the one in Figure 10.7. Deltas Deposition also occurs when a stream or river empties into a large body of still water. In this case, a delta forms. A delta is shaped like a triangle. It spreads out into the body of water. An example is shown in Figure 10.7. "
Which of the following has the smallest grains?,(A) breccia (B) conglomerate (C) siltstone (D) sandstone,C,"Make at least half your daily grain choices whole grains. Examples of whole grains are whole wheat bread, whole wheat pasta, and brown rice. Choose a variety of different vegetables each day. Be sure to include both dark green vegetables, such as spinach and broccoli, and orange vegetables, such as carrots and sweet potatoes. Choose a variety of different fruits each day. Select mainly fresh fruits rather than canned fruits, and whole fruits instead of fruit juices. When choosing oils, choose unsaturated oils, such as olive oil, canola oil, or vegetable oil. Choose low-fat or fat-free milk and other dairy products. For example, select fat-free yogurt and low-fat cheese. For meats, choose fish, chicken, and lean cuts of beef. Also, be sure to include beans, nuts, and seeds. "
Which of the following sedimentary rocks contains the smallest sediments?,(A) conglomerate (B) sandstone (C) siltstone (D) shale,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
The processes by which sediments harden into rock include,(A) compaction (B) sedimentation (C) dissolution (D) precipitation,A,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Clastic sedimentary rocks are classified by,(A) the presence or absence of fossils (B) how hard they are (C) the size of the sediments they are made of (D) the location where they precipitated,C,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
Which of the following rocks is not a clastic sedimentary rock?,(A) limestone (B) breccia (C) halite (D) two of the above,C,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
"The White House in Washington, D.C., is made of",(A) clastic rock (B) sedimentary rock (C) sandstone (D) all of the above,D,"Building materials need to be both strong and flexible. Small structures, like houses, should bend and sway. Wood and steel bend. Brick, stone, and adobe are brittle and will break. Larger buildings must sway, but not so much that they touch nearby buildings. Counterweights and diagonal steel beams can hold down sway. Buildings need strong, flexible connections where the walls meet the foundation. Earthquake-safe buildings are well connected (Figure Steel or wood can be added to older buildings to reinforce a buildings structure and its connections (Figure 7.42). Elevated freeways and bridges can also be reinforced so that they do not collapse. Important structures must be designed to survive intact. "
Which of the following is NOT a fossil?,(A) dinosaur footprints (B) mammoth bones (C) ancient human hair preserved in cave sediments (D) a modern shell on the beach,D,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
"When sediments settle out of water, they form",(A) chemical rocks (B) horizontal layers (C) precipitates (D) none of the above,B,"Most sedimentary rocks form from sediments. Sediments are small pieces of other rocks, like pebbles, sand, silt, and clay. Sedimentary rocks may include fossils. Fossils are materials left behind by once-living organisms. Fossils can be pieces of the organism, like bones. They can also be traces of the organism, like footprints. Most often, sediments settle out of water (Figure 4.13). For example, rivers carry lots of sediment. Where the water slows, it dumps these sediments along its banks, into lakes and the ocean. When sediments settle out of water, they form horizontal layers. A layer of sediment is deposited. Then the next layer is deposited on top of that layer. So each layer in a sedimentary rock is younger than the layer under it. It is older than the layer over it. Sediments are deposited in many different types of environments. Beaches and deserts collect large deposits of sand. Sediments also continuously wind up at the bottom of the ocean and in lakes, ponds, rivers, marshes, and swamps. Avalanches produce large piles of sediment. The environment where the sediments are deposited determines the type of sedimentary rock that can form. "
Which sedimentary rock is formed of rounded stones that have been cemented together?,(A) breccia (B) sandstone (C) conglomerate (D) limestone,C,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
Sandstone is very porous so water can move easily through it.,(A) true (B) false,A,"Water infiltrates the ground because soil and rock are porous. Between the grains are pores, or tiny holes. Since water can move through this rock it is permeable. Eventually, the water reaches a layer of rock that is not porous and so is impermeable. Water stops moving downward when it reaches this layer of rock. Look at the diagram in Figure 13.11. It shows two layers of porous rock. The top layer is not saturated; it is not full of water. The next layer is saturated. The water in this layer has nowhere else to go. It cannot seep any deeper into the ground because the rock below it is impermeable. "
Sedimentary rocks may contain fossils.,(A) true (B) false,A,The process by which remains or traces of living things become fossils is called fossilization. Most fossils are preserved in sedimentary rocks. 
Avalanches produce horizontal layers of sediments.,(A) true (B) false,B,"Sediments were deposited in ancient seas in horizontal, or flat, layers. If sedimentary rock layers are tilted, they must have moved after they were deposited. "
"Like minerals, rocks cannot include organic materials.",(A) true (B) false,B,"A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. "
Particles of silt are smaller than particles of clay.,(A) true (B) false,B,"The size of particles determines how they are carried by flowing water. This is illustrated in Figure 10.2. Minerals that dissolve in water form salts. The salts are carried in solution. They are mixed thoroughly with the water. Small particles, such as clay and silt, are carried in suspension. They are mixed throughout the water. These particles are not dissolved in the water. Somewhat bigger particles, such as sand, are moved by saltation. The particles move in little jumps near the stream bottom. They are nudged along by water and other particles. The biggest particles, including gravel and pebbles, are moved by traction. In this process, the particles roll or drag along the bottom of the water. "
Breccia and conglomerate have large sediments that have different shapes.,(A) true (B) false,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
Fossils are always the remains of bones or teeth.,(A) true (B) false,B,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
Sediments are pieces of rock.,(A) true (B) false,A,"Most sedimentary rocks form from sediments. Sediments are small pieces of other rocks, like pebbles, sand, silt, and clay. Sedimentary rocks may include fossils. Fossils are materials left behind by once-living organisms. Fossils can be pieces of the organism, like bones. They can also be traces of the organism, like footprints. Most often, sediments settle out of water (Figure 4.13). For example, rivers carry lots of sediment. Where the water slows, it dumps these sediments along its banks, into lakes and the ocean. When sediments settle out of water, they form horizontal layers. A layer of sediment is deposited. Then the next layer is deposited on top of that layer. So each layer in a sedimentary rock is younger than the layer under it. It is older than the layer over it. Sediments are deposited in many different types of environments. Beaches and deserts collect large deposits of sand. Sediments also continuously wind up at the bottom of the ocean and in lakes, ponds, rivers, marshes, and swamps. Avalanches produce large piles of sediment. The environment where the sediments are deposited determines the type of sedimentary rock that can form. "
Coal is not a sedimentary rock.,(A) true (B) false,B,"Coal is a black or brownish-black rock that burns easily (Figure 5.3). Most coal is sedimentary rock. The hardest type of coal, anthracite, is a metamorphic rock. That is because it is exposed to higher temperature and pressure as it forms. Coal is mostly carbon, but some other elements can be found in coal, including sulfur. "
Sediments on a beach may include cobbles and pebbles.,(A) true (B) false,A,"In relatively quiet areas along a shore, waves may deposit sand. Sand forms a beach, like the one in Figure 10.13. Many beaches include bits of rock and shell. You can see a close-up photo of beach deposits in Figure 10.14. "
Cementation occurs when the fluids in the free spaces of the sediments crystallize.,(A) true (B) false,A,Sedimentary rocks form in two ways. Particles may be cemented together. Chemicals may precipitate. 
A rock that includes fossil fragments is a bioclastic rock.,(A) true (B) false,A,The process by which remains or traces of living things become fossils is called fossilization. Most fossils are preserved in sedimentary rocks. 
All sedimentary rocks form from sediments.,(A) true (B) false,B,"Most sedimentary rocks form from sediments. Sediments are small pieces of other rocks, like pebbles, sand, silt, and clay. Sedimentary rocks may include fossils. Fossils are materials left behind by once-living organisms. Fossils can be pieces of the organism, like bones. They can also be traces of the organism, like footprints. Most often, sediments settle out of water (Figure 4.13). For example, rivers carry lots of sediment. Where the water slows, it dumps these sediments along its banks, into lakes and the ocean. When sediments settle out of water, they form horizontal layers. A layer of sediment is deposited. Then the next layer is deposited on top of that layer. So each layer in a sedimentary rock is younger than the layer under it. It is older than the layer over it. Sediments are deposited in many different types of environments. Beaches and deserts collect large deposits of sand. Sediments also continuously wind up at the bottom of the ocean and in lakes, ponds, rivers, marshes, and swamps. Avalanches produce large piles of sediment. The environment where the sediments are deposited determines the type of sedimentary rock that can form. "
Shale may contain hardened mud.,(A) true (B) false,A,Sedimentary rocks form in two ways. Particles may be cemented together. Chemicals may precipitate. 
Limestone is a chemical sedimentary rock.,(A) true (B) false,B,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
type of sedimentary rock that forms when crystals precipitate out of liquid,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,G,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
squeezed together by upper layers of sediments,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,C,"Sedimentary rocks are formed in horizontal layers. This is magnificently displayed around the southwestern United States. The arid climate allows rock layers to be well exposed (Figure 7.4). The lowest layers are the oldest and the higher layers are younger. Folds, joints and faults are caused by stresses. Figure 7.5 shows joints in a granite hillside. If a sedimentary rock is tilted or folded, we know that stresses have changed the rock (Figure 7.6). "
type of sedimentary rock that forms when rock fragments are compacted and cemented together,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,B,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
preserved material left behind by a once-living organism,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,F,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces). Collections of fossils are known as fossil assemblages. Click image to the left or use the URL below. URL: "
stuck together by minerals that fill in spaces between sediments,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
example of a clastic sedimentary rock,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
example of a chemical sedimentary rock,(A) cemented (B) clastic sedimentary rock (C) compacted (D) sandstone (E) rock salt (F) fossil (G) chemical sedimentary rock,E,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
type of metamorphism in which magma contacts a rock and changes it by extreme heat,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,C,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
Metamorphism occurs when there is,(A) heat only (B) pressure only (C) heat and pressure together (D) all of the above,D,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
Any rock formed by extreme heat and pressure,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Metamorphic rocks change,(A) physically only (B) chemically only (C) physically and chemically together (D) any of the above,D,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
metamorphic rock with alternating bands of light and dark crystals,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,D,"Metamorphic rocks start off as some kind of rock. The starting rock can be igneous, sedimentary or even another metamorphic rock. Heat and/or pressure then change the rocks physical or chemical makeup. During metamorphism a rock may change chemically. Ions move and new minerals form. The new minerals are more stable in the new environment. Extreme pressure may lead to physical changes like foliation. Foliation forms as the rocks are squeezed. If pressure is exerted from one direction, the rock forms layers. This is foliation. If pressure is exerted from all directions, the rock usually does not show foliation. There are two main types of metamorphism: 1. Contact metamorphism results when magma contacts a rock, changing it by extreme heat (Figure 4.14). 2. Regional metamorphism occurs over a wide area. Great masses of rock are exposed to pressure from rock and sediment layers on top of it. The rock may also be compressed by other geological processes. Metamorphism does not cause a rock to melt completely. It only causes the minerals to change by heat or pressure. Hornfels is a rock with alternating bands of dark and light crystals. Hornfels is a good example of how minerals rearrange themselves during metamorphism (Figure 4.14). The minerals in hornfels separate by density. The result is that the rock becomes banded. Gneiss forms by regional metamorphism from extremely high temperature and pressure. "
Contact metamorphism is caused by,(A) heat from magma (B) water pressure (C) the weight of overlying rock (D) atmospheric pressure,A,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
Metamorphism changes rocks because,(A) the minerals need to be stable under new conditions (B) the rocks melt (C) atoms break apart to form new atoms (D) the pressure causes foliation in each mineral,A,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
type of metamorphism in which great masses of rock are exposed to extreme pressure,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,A,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
formation of layers in some metamorphic rock,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,E,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
Regional metamorphism can be the result of,(A) extreme heat (B) fluid infiltration (C) intense pressure from all directions (D) melting,C,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
metamorphic rock that is crushed and used to build railroad tracks,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,G,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
metamorphic rock that is used to make statues,(A) regional metamorphism (B) metamorphic rock (C) contact metamorphism (D) hornfels (E) foliation (F) marble (G) quartzite,F,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
Foliation occurs when pressure is exerted from all directions equally.,(A) true (B) false,B,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
Regional metamorphism may expose rocks to high pressure and low temperature.,(A) true (B) false,A,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
A metamorphic rock can be metamorphosed.,(A) true (B) false,A,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
A metamorphic rock nearly always resembles its original parent rock.,(A) true (B) false,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Metamorphic rocks can always be distinguished from igneous and sedimentary rocks because they are,(A) true (B) false,B,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
"When a rock undergoes metamorphism, it becomes an entirely new type of rock.",(A) true (B) false,A,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
"During metamorphism, ions may move and new minerals may form.",(A) true (B) false,A,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
There are two types of metamorphism.,(A) true (B) false,A,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
Contact metamorphism causes rock to melt and form magma.,(A) true (B) false,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
The most commonly used metamorphic rocks are slate and gneiss.,(A) true (B) false,B,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
Quartzite is a relatively soft metamorphic rock.,(A) true (B) false,B,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
Gneiss forms by contact metamorphism.,(A) true (B) false,B,"Metamorphic rocks start off as some kind of rock. The starting rock can be igneous, sedimentary or even another metamorphic rock. Heat and/or pressure then change the rocks physical or chemical makeup. During metamorphism a rock may change chemically. Ions move and new minerals form. The new minerals are more stable in the new environment. Extreme pressure may lead to physical changes like foliation. Foliation forms as the rocks are squeezed. If pressure is exerted from one direction, the rock forms layers. This is foliation. If pressure is exerted from all directions, the rock usually does not show foliation. There are two main types of metamorphism: 1. Contact metamorphism results when magma contacts a rock, changing it by extreme heat (Figure 4.14). 2. Regional metamorphism occurs over a wide area. Great masses of rock are exposed to pressure from rock and sediment layers on top of it. The rock may also be compressed by other geological processes. Metamorphism does not cause a rock to melt completely. It only causes the minerals to change by heat or pressure. Hornfels is a rock with alternating bands of dark and light crystals. Hornfels is a good example of how minerals rearrange themselves during metamorphism (Figure 4.14). The minerals in hornfels separate by density. The result is that the rock becomes banded. Gneiss forms by regional metamorphism from extremely high temperature and pressure. "
Schist is sometimes used as a landscaping material.,(A) true (B) false,A,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
"In the 1500s, Michelangelo carved statues from marble.",(A) true (B) false,A,Mendel was an Austrian Monk who lived in the 1800s. You can see his picture in Figure 6.1. 
Metamorphic rocks cannot undergo further metamorphism and change to different types of rocks.,(A) true (B) false,B,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
"During metamorphism, rocks may change",(A) chemically (B) physically (C) permanently (D) two of the above,D,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Metamorphism begins with,(A) magma (B) sediments (C) lava (D) rock,D,"Metamorphic rocks start off as some kind of rock. The starting rock can be igneous, sedimentary or even another metamorphic rock. Heat and/or pressure then change the rocks physical or chemical makeup. During metamorphism a rock may change chemically. Ions move and new minerals form. The new minerals are more stable in the new environment. Extreme pressure may lead to physical changes like foliation. Foliation forms as the rocks are squeezed. If pressure is exerted from one direction, the rock forms layers. This is foliation. If pressure is exerted from all directions, the rock usually does not show foliation. There are two main types of metamorphism: 1. Contact metamorphism results when magma contacts a rock, changing it by extreme heat (Figure 4.14). 2. Regional metamorphism occurs over a wide area. Great masses of rock are exposed to pressure from rock and sediment layers on top of it. The rock may also be compressed by other geological processes. Metamorphism does not cause a rock to melt completely. It only causes the minerals to change by heat or pressure. Hornfels is a rock with alternating bands of dark and light crystals. Hornfels is a good example of how minerals rearrange themselves during metamorphism (Figure 4.14). The minerals in hornfels separate by density. The result is that the rock becomes banded. Gneiss forms by regional metamorphism from extremely high temperature and pressure. "
What type of change in rock is foliation?,(A) physical change (B) chemical change (C) mineral change (D) two of the above,A,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
A metamorphic rock may undergo foliation when pressure is,(A) exerted from just one direction (B) exerted from all directions (C) relatively weak (D) absent,A,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
Slate is a metamorphic rock that is used for,(A) building (B) landscaping (C) statues (D) two of the above,D,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
Which of the following types of rocks can undergo metamorphism?,(A) sedimentary rock (B) igneous rock (C) metamorphic rock (D) all of the above,D,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
All of the following are metamorphic rocks except,(A) schist (B) quartzite (C) gneiss (D) granite,D,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
any material that stores energy and releases it in a chemical change,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,G,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
law that energy cannot be created or destroyed,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,F,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
energy that has the potential to do work,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,E,"The concept of energy was first introduced in the chapter ""States of Matter,"" where it is defined as the ability to cause change in matter. Energy can also be defined as the ability to do work. Work is done whenever a force is used to move matter. When work is done, energy is transferred from one object to another. For example, when the batter in Figure 17.2 uses energy to swing the bat, she transfers energy to the bat. The moving bat, in turn, transfers energy to the ball. Like work, energy is measured in the joule (J), or newtonmeter (Nm). Energy exists in different forms, which you can read about in the lesson ""Forms of Energy"" later in the chapter. Some forms of energy are mechanical, electrical, and chemical energy. Most forms of energy can also be classified as kinetic or potential energy. Kinetic and potential forms of mechanical energy are the focus of this lesson. Mechanical energy is the energy of objects that are moving or have the potential to move. "
"coal, oil, or natural gas",(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,D,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
ability to move or change matter,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,A,"Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. "
form of energy obtained from food,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,B,"Everything you do takes energy. Energy is the ability to change or move matter. Whether its reading these words or running a sprint, it requires energy. In fact, it takes energy just to stay alive. Where do you get energy? You probably know the answer. You get energy from food. Figure {{ref|MS-LS-SE-02-03-Food|below}] shows some healthy foods that can provide you with energy. Just like you, other living things need a source of energy. But they may use a different source. Organisms may be grouped on the basis of the source of energy they use. In which group do you belong? Producers such as the tree in Figure 2.1 use sunlight for energy to produce their own food. The process is called photosynthesis, and the food is sugar. Plants and other organisms use this food for energy. Consumers such as the raccoon in Figure 2.1 eat plantsor other consumers that eat plantsas a source of energy. Some consumers such as the mushroom in Figure 2.1 get their energy from dead organic matter. For example, they might consume dead leaves on a forest floor. "
energy of moving matter,(A) energy (B) chemical energy (C) kinetic energy (D) fossil fuel (E) potential energy (F) conservation of energy (G) fuel,C,"Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. "
Plants make food using energy from soil nutrients.,(A) true (B) false,B,"If a plant gets hungry, it cannot walk to a local restaurant and buy a slice of pizza. So, how does a plant get the food it needs to survive? Plants are producers, which means they are able to make, or produce, their own food. They also produce the ""food"" for other organisms. Plants are also autotrophs. Autotrophs are the organisms that collect the energy from the sun and turn it into organic compounds. Using the energy from the sun, they produce complex organic compounds from simple inorganic molecules. So once again, how does a plant get the food it needs to survive? Through photosynthesis. Photosynthesis is the process plants use to make their own food from the suns energy, carbon dioxide, and water. During photosynthesis, carbon dioxide and water combine with solar energy to create glucose, a carbohydrate (C6 H12 O6 ), and oxygen. The process can be summarized as: in the presence of sunlight, carbon dioxide + water  glucose + oxygen. Glucose, the main product of photosynthesis, is a sugar that acts as the ""food"" source for plants. The glucose is then converted into usable chemical energy, ATP, during cellular respiration. The oxygen formed during photosynthesis, which is necessary for animal life, is essentially a waste product of the photosynthesis process. Actually, almost all organisms obtain their energy from photosynthetic organisms. For example, if a bird eats a caterpillar, then the bird gets the energy that the caterpillar gets from the plants it eats. So the bird indirectly gets energy that began with the glucose formed through photosynthesis. Therefore, the process of photosynthesis is central to sustaining life on Earth. In eukaryotic organisms, photosynthesis occurs in chloroplasts. Only cells with chloroplastsplant cells and algal (protist) cellscan perform photosynthesis. Animal cells and fungal cells do not have chloroplasts and, therefore, cannot photosynthesize. That is why these organisms, as well as the non- photosynthetic protists, rely on other organisms to obtain their energy. These organisms are heterotrophs. The Photosynthesis Song explaining photosynthesis, can be heard at  Click image to the left or use the URL below. URL: "
Fossil fuels are made of minerals and rocks.,(A) true (B) false,B,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
Uneven heating by the sun causes wind.,(A) true (B) false,A,"The energy from the Sun creates wind (Figure 5.11). Wind energy moves by convection. The Sun heats some locations more than others. Warm air rises, so other air rushes in to fill the hole left by the rising air. This horizontal movement of air is called wind. "
The suns energy drives the water cycle.,(A) true (B) false,A,"The Sun, many millions of kilometers away, provides the energy that drives the water cycle. Our nearest star directly impacts the water cycle by supplying the energy needed for evaporation. "
Kicking a soccer ball changes kinetic energy to potential energy.,(A) true (B) false,B,"Here is an example of how energy changes form: kicking a soccer ball. Your body gets energy from food. Where does the food get its energy? If youre eating a plant, then the energy comes directly from the Sun. If youre eating an animal, then the energy comes from a plant that got its energy from the Sun. Your body breaks down the food. It converts the food to chemical energy and stores it. When you are about to kick the ball, the energy must be changed again. Potential energy has the potential to do work. When your leg is poised to kick the ball but is not yet moving, your leg has potential energy. A ball at the top of a hill has the potential energy of location. Kinetic energy is the energy of anything in motion. Your muscles move your leg, your foot kicks the ball, and the ball gains kinetic energy (Figure 5.1). The kinetic energy was converted from potential energy that was in your leg before the kick. The action of kicking the ball is energy changing forms. The same is true for anything that involves change. "
The head of a match stores chemical energy.,(A) true (B) false,A,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
It takes millions of years for fossil fuels to form.,(A) true (B) false,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
Most fossil fuels will last for another 500 years.,(A) true (B) false,B,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
Trees are a source of biomass energy.,(A) true (B) false,A,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
Geothermal energy is a nonrenewable resource.,(A) true (B) false,B,"Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the uranium needed for nuclear power will soon be used up if we continue to consume them at these rates. Using fossil fuels and nuclear energy creates other problems as well. The burning of fossil fuels releases carbon dioxide into the atmosphere. This is one of the major greenhouse gases causing global climate change. Nuclear power creates another set of problems, including the disposal of radioactive waste. "
Sources of energy on Earth include the,(A) sun (B) planets internal heat (C) decay of radioactive elements (D) all of the above,D,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
What happens when energy changes form?,(A) Some of the energy is lost (B) The amount of energy increases (C) The energy is generally used up (D) The amount of energy remains the same,D,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
An example of potential energy is a child who is,(A) running (B) swimming (C) sitting at the top of a slide (D) none of the above,C,"If you think about different sources of energysuch as batteries and the sunyou probably realize that energy can take different forms. For example, when the boy swings his tennis racket, the energy of the moving racket is an example of mechanical energy. To move his racket, the boy needs energy stored in food, which is an example of chemical energy. Other forms of energy include electrical, thermal, light, and sound energy. The different forms of energy can also be classified as either kinetic energy or potential energy. Kinetic energy is the energy of moving matter. Potential energy is energy that is stored in matter. Q: Is the chemical energy in food kinetic energy or potential energy? A: The chemical energy in food is potential energy. It is stored in the chemical bonds that make up food molecules. The stored energy is released when we digest food. Then we can use it for many purposes, such as moving (mechanical energy) or staying warm (thermal energy). Q: What is an example of kinetic energy? A: Anything that is moving has kinetic energy. An example is a moving tennis racket. "
An example of kinetic energy is a child who is,(A) running (B) swimming (C) sliding down a slide (D) all of the above,D,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
Most electricity used in homes comes from,(A) batteries (B) power plants (C) biomass fuels (D) solar energy,B,"Figure 20.10 shows the major ways energy is used in the U.S. A lot of energy is used in homes. In fact, more energy is used in homes than in stores and businesses. Even more energy is used for transportation. A lot of fuel is necessary to move people and goods around the country. Industry uses the most energy. Industrial uses account for one-third of all the energy used in the U.S. "
Which statement is true of all renewable resources?,(A) They will never run out (B) They can be used unsustainably (C) They have no drawbacks (D) none of the above,D,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
The energy stored in fossil fuels came originally from,(A) rocks (B) magma (C) the sun (D) dinosaurs,C,"When ancient plants underwent photosynthesis, they changed energy in sunlight to stored chemical energy in food. The plants used the food and so did the organisms that ate the plants. After the plants and other organisms died, their remains gradually changed to fossil fuels as they were covered and compressed by layers of sediments. Petroleum and natural gas formed from ocean organisms and are found together. Coal formed from giant tree ferns and other swamp plants. "
"To be useful, oil must be located in a(n) _________ rock layer and trapped by a(n) _________ rock layer.",(A) impermeable (B) permeable (C) b permeable (D) impermeable (E) c impermeable (F) impermeable (G) d permeable (H) permeable,B,"In order to be collected, the oil must be located between a porous rock layer and an impermeable layer (Figure 1.1). Trapped above the porous rock layer and beneath the impermeable layer, the oil will remain between these layers until it is extracted from the rock. Oil (red) is found in the porous rock layer (yellow) and trapped by the impermeable layer (brown). The folded structure has allowed the oil to pool so a well can be drilled into the reservoir. To separate the different types of hydrocarbons in crude oil for different uses, the crude oil must be refined in refineries like the one shown in Figure 1.2. Refining is possible because each hydrocarbon in crude oil boils at a different temperature. When the oil is boiled in the refinery, separate equipment collects the different compounds. "
Which of the following fuels produces the least amount of carbon dioxide per unit of energy?,(A) coal (B) oil (C) natural gas (D) all of these produce the same amount of carbon dioxide,C,"When fossil fuels burn, they release thermal energy, water vapor, and carbon dioxide. The thermal energy can be used to generate electricity or do other work. The carbon dioxide is released into the atmosphere and is a major cause of global climate change. The burning of fossil fuels also releases many pollutants into the air. Pollutants such as sulfur dioxide form acid rain, which kills living things and damages metals, stonework, and other materials. Pollutants such as nitrogen oxides cause smog, which is harmful to human health. Tiny particles, or particulates, released when fossil fuels burn also harm human health. The Figure 1.2 shows the amounts of pollutants released by different fossil fuels. Natural gas releases the least pollution; coal releases the most. Petroleum has the additional risk of oil spills, which may seriously damage ecosystems. Q: Some newer models of cars and other motor vehicles can run on natural gas. Why would a natural gas vehicle be better for the environment than a vehicle that burns gasoline, which is made from oil? A: Natural gas produces much less pollution and carbon dioxide when it burns than gasoline does. So a natural gas vehicle would contribute less to global climate change, acid rain, and air pollution that harms health. Besides being better for the environment, burning natural gas instead of gasoline results in less engine wear and provides more energy for a given amount of fuel. "
Fuel made primarily of methane is called,(A) coal (B) petroleum (C) natural gas (D) liquid gas,C,Natural gas is mostly methane. 
The main gases that are a by-product of burning gasoline are,(A) water vapor and carbon dioxide (B) carbon dioxide and sulfur compounds (C) sulfur compounds and nitrogen compounds (D) nitrogen compounds and carbon dioxide,A,Using gasoline to power automobiles affects the environment. The exhaust fumes from burning gasoline cause air pollution. These pollutants include smog and ground-level ozone. Air pollution is a big problem for cities where large numbers of people drive every day. Burning gasoline also produces carbon dioxide. This is a greenhouse gas and is a cause of global warming. Similar pollutants come from other forms of oil. 
Nuclear power that is currently in use comes from.,(A) combustion of uranium atoms (B) splitting uranium atoms (C) fusing uranium atoms (D) breaking electrons away from a uranium atom,B,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
fossil fuel that produces the least pollution when burned,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,D,"We can reduce our use of fossil fuels in several ways: Conserve fossil fuels. For example, turning out lights when we arent using them saves electricity. Why does this help? A lot of the electricity we use comes from coal-burning power plants. Use fossil fuels more efficiently. For example, driving a fuel-efficient car lets you go farther on each gallon of gas. This can add up to a big savings in fossil fuel use. Change to alternative energy sources that produce little or no air pollution. For example, hybrid cars run on electricity that would be wasted during braking. These cars use gas only as a backup fuel. As a result, they produce just 10 percent of the air pollution produced by cars that run only on gas. Cars that run on hydrogen and produce no pollution at all have also been developed (see Figure 22.14). "
hardest form of coal,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,F,"Coal is a black or brownish-black rock that burns easily (Figure 5.3). Most coal is sedimentary rock. The hardest type of coal, anthracite, is a metamorphic rock. That is because it is exposed to higher temperature and pressure as it forms. Coal is mostly carbon, but some other elements can be found in coal, including sulfur. "
solid fossil fuel,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,G,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
Fossil fuels come from the remains of ancient organisms.,(A) true (B) false,A,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
element used to produce nuclear power,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,C,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
"Hydrocarbons are all liquids, like gasoline.",(A) true (B) false,B,"Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds. Nonetheless, they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms, but large hydrocarbons may have hundreds. The size of hydrocarbon molecules influences their properties. For example, it influences their boiling and melting points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar and do not dissolve in water. In fact, they tend to repel water. Thats why they are used in floor wax and similar products. Hydrocarbons can be classified in two basic classes. The classes are saturated hydrocarbons and unsaturated hydrocarbons. This classification is based on the number of bonds between carbon atoms. You can learn more about both types of hydrocarbons at this URL:  (6:41). MEDIA Click image to the left or use the URL below. URL: "
liquid fossil fuel,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,E,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
main component of natural gas,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,A,Natural gas is mostly methane. 
Oil and gas will fill our needs for a time period on the order of thousands of years.,(A) true (B) false,B,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
any compound consisting of carbon and hydrogen,(A) methane (B) hydrocarbon (C) uranium (D) natural gas (E) petroleum (F) anthracite (G) coal,B,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
Nuclear power plants produce so much energy because the process is not controlled.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Natural gas is useful as a fuel more-or-less as it comes out of the ground.,(A) true (B) false,A,Natural gas is mostly methane. 
Which fossil fuel formed from dead plants that settled to the bottom of swamps millions of years ago?,(A) coal (B) crude oil (C) petroleum (D) natural gas,A,"Coal forms from dead plants that settled at the bottom of ancient swamps. Lush coal swamps were common in the tropics during the Carboniferous period, which took place more than 300 million years ago (Figure 1.2). The climate was warmer then. Mud and other dead plants buried the organic material in the swamp, and burial kept oxygen away. When plants are buried without oxygen, the organic material can be preserved or fossilized. Sand and clay settling on top of the decaying plants squeezed out the water and other substances. Millions of years later, what remains is a carbon- containing rock that we know as coal. "
What happens to crude oil at a refinery?,(A) It is separated into different compounds (B) It is removed from rock layers (C) It is heated (D) two of the above,D,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
Which products are made from crude oil?,(A) gasoline (B) plastic (C) fertilizer (D) all of the above,D,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
The fossil fuel that is the biggest contributor to global warming is,(A) oil (B) coal (C) diesel fuel (D) natural gas,B,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
Dead organisms turn to fossil fuels when they are exposed to,(A) oxygen (B) sulfuric acid (C) heat and pressure (D) underground water,C,"Millions of years ago, there were so many dead plants and animals that they could not completely decompose before they were buried. They were covered over by soil or sand, tar or ice. These dead plants and animals are organic matter made out of cells full of carbon-containing organic compounds (carbohydrates, lipids, proteins and nucleic acids). What happened to all this carbon? When organic matter is under pressure for millions of years, it forms fossil fuels. Fossil fuels are coal, oil, and natural gas. When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure 1.2). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas, since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earths temperature, known as global warming or global climate change. "
Which statement about natural gas is false?,(A) It releases no air pollutants when burned (B) It forms at higher temperatures than crude oil (C) It must be processed before it is used as a fuel (D) It produces less carbon dioxide than other fossil fuels,A,Natural gas is mostly methane. 
What does a properly operating nuclear power plant release into the air?,(A) carbon dioxide (B) sulfur dioxide (C) particulates (D) steam,D,"Nuclear power is clean. It does not pollute the air. However, the use of nuclear energy does create other environ- mental problems. Uranium must be mined (Figure 1.3). The process of splitting atoms creates radioactive waste, which remains dangerous for thousands or hundreds of thousands of years. As yet, there is no long-term solution for storing this waste. The development of nuclear power plants has been on hold for three decades. Accidents at Three Mile Island and Chernobyl, Ukraine verified peoples worst fears about the dangers of harnessing nuclear power (Figure 1.4). Recently, nuclear power appeared to be making a comeback as society looked for alternatives to fossil fuels. After all, nuclear power emits no pollutants, including no greenhouse gases. But the 2011 disaster at the Fukushima Daiichi Nuclear Power Plant in Japan may have resulted in a new fear of nuclear power. The cause of the disaster was a 9.0 magnitude earthquake and subsequent tsunami, which compromised the plant. Although a total meltdown was averted, the plant experienced multiple partial meltdowns, core breaches, radiation releases, and cooling failures. The plant is scheduled for a complete cold shutdown before the end of 2011. Damaged building near the site of the Chernobyl disaster. Nuclear power is a controversial subject in California and most other places. Nuclear power has no pollutants including carbon emissions, but power plants are not always safe and the long-term disposal of wastes is a problem that has not yet been solved. The future of nuclear power is murky. "
Fossil fuels are compounds known as hydrocarbons.,(A) true (B) false,A,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
"Unlike other types of coal, anthracite is igneous rock.",(A) true (B) false,B,"Coal is a black or brownish-black rock that burns easily (Figure 5.3). Most coal is sedimentary rock. The hardest type of coal, anthracite, is a metamorphic rock. That is because it is exposed to higher temperature and pressure as it forms. Coal is mostly carbon, but some other elements can be found in coal, including sulfur. "
Most of the coal in the United States is found in the Rocky Mountains.,(A) true (B) false,B,"Around the world, coal is the largest source of energy for electricity. The United States is rich in coal (Figure 1.3). California once had a number of small coal mines, but the state no longer produces coal. To turn coal into electricity, the rock is crushed into powder, which is then burned in a furnace that has a boiler. Like other fuels, coal releases its energy as heat when it burns. Heat from the burning coal boils the water in the boiler to make steam. The steam spins turbines, which turn generators to create electricity. In this way, the energy stored in the coal is converted to useful energy like electricity. "
Petroleum formed at the bottom of ancient seas.,(A) true (B) false,A,"The way oil forms is similar in many ways to coal. Tiny organisms like plankton and algae die and settle to the bottom of the sea. Sediments settle over the organic material. Oxygen is kept away by the sediments. When the material is buried deep enough, it is exposed to high heat and pressure. Over millions of years, the organic material transforms into liquid oil. "
The United States produces more oil than it uses.,(A) true (B) false,B,"The United States does produce oil, but the amount produced is only about one-quarter as much as the nation uses. The United States has only about 1.5% of the worlds proven oil reserves, so most of the oil used by Americans must be imported from other nations. The main oil-producing regions in the United States are the Gulf of Mexico, Texas, Alaska, and California (Figure As in every type of mining, mining for oil has environmental consequences. Oil rigs are unsightly (Figure 1.4), and spills are too common (Figure 1.5). Click image to the left or use the URL below. URL:  Offshore well locations in the Gulf of Mex- ico. Note that some wells are located in very deep water. Drill rigs at the San Ardo Oil Field in Monterey, California. "
Burning gasoline leads to smog and ground-level ozone.,(A) true (B) false,A,Using gasoline to power automobiles affects the environment. The exhaust fumes from burning gasoline cause air pollution. These pollutants include smog and ground-level ozone. Air pollution is a big problem for cities where large numbers of people drive every day. Burning gasoline also produces carbon dioxide. This is a greenhouse gas and is a cause of global warming. Similar pollutants come from other forms of oil. 
Natural gas is obtained from Earths atmosphere.,(A) true (B) false,B,Natural gas is mostly methane. 
Most coal contains the element sulfur.,(A) true (B) false,A,"For coal to be used as an energy source, it must first be mined. Coal mining occurs at the surface or underground by methods that are described in the the chapter Materials of Earths Crust (Figure 1.4). Mining, especially underground The location of the continents during the Carboniferous period. Notice that quite a lot of land area is in the region of the tropics. mining, can be dangerous. In April 2010, 29 miners were killed at a West Virginia coal mine when gas that had accumulated in the mine tunnels exploded and started a fire. Coal mining exposes minerals and rocks from underground to air and water at the surface. Many of these minerals contain the element sulfur, which mixes with air and water to make sulfuric acid, a highly corrosive chemical. If the sulfuric acid gets into streams, it can kill fish, plants, and animals that live in or near the water. Click image to the left or use the URL below. URL: "
Nuclear energy is a renewable energy resource.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Fuel rods in nuclear power plants are made of carbon.,(A) true (B) false,B,"Nuclear power plants use uranium that has been concentrated in fuel rods (Figure 5.6). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion. Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. "
The primary barrier to solar energy use is that it,(A) is not technically feasible (B) causes major pollution problems (C) is too expensive compared to other energy sources (D) all of these,C,"Solar energy has many benefits. It does not produce any pollution. There is plenty of it available, much more than we could possibly use. But solar energy has problems. The Sun doesnt shine at night. A special battery is needed to store extra energy during the day for use at night. The technology for most uses of solar energy is still expensive. Until solar technology becomes more affordable, most people will prefer to get their energy from other sources. "
Hydroelectric plants,(A) produce a lot of greenhouse gases (B) create a reservoir that may bury natural or cultural resources (C) release sediment that can bury a landscape (D) produce nitric acid that falls as acid rain,B,Many of the suitable streams in the United States have been developed for hydroelectric power. Many streams worldwide also have hydroelectric plants. Hydropower is a major source of Californias electricity. It accounts for about 14.5 percent of the total. Most of Californias nearly 400 hydroelectric power plants are located in the Sierra Nevada mountains. 
Wind power,(A) comes indirectly from solar energy (B) is cheap to harness on a large scale (C) is welcomed by people everywhere (D) produces a lot of greenhouse gases,A,"Wind power uses moving air as a source of energy. Some types of wind power have been around for a long time. People have used windmills to grind grain and pump water for hundreds of years. Sailing ships have depended on wind for millennia. Wind is now used to generate electricity. Moving air can make a turbine spin, just like moving water can. Moving air has kinetic energy. When wind hits the blades of the turbine, the kinetic energy makes the blades move. The turbine spins and creates electricity. "
Geothermal energy,(A) has extreme safety issues because it is so hot (B) is best where hot water comes to the surface (C) requires cool water be pumped into the ground (D) produces a lot of greenhouse gases,B,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
"When energy moves through material, but the material itself does not move, this is",(A) radiation (B) convection (C) electromagnetism (D) conduction,D,"Electric current cannot travel through empty space. It needs a material through which to travel. However, when current travels through a material, the flowing electrons collide with particles of the material, and this creates resistance. "
"If we could harness it, which of the following energy sources could provide all the energy needed by people around the world for billions of years?",(A) wind (B) water (C) biomass (D) geothermal,D,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
Solar energy is used to,(A) heat water (B) heat homes (C) generate electricity (D) all of the above,D,"Solar energy is used to heat homes and water, and to make electricity. Scientists and engineers have many ways to get energy from the Sun (Figure 5.9). One is by using solar cells. Solar cells are devices that turn sunlight directly into electricity. Lots of solar cells make up an individual solar panel. You may have seen solar panels on roof tops. The Suns heat can also be trapped in your home by using south facing windows and good insulation. "
Possible sources of water power include,(A) streams (B) waves (C) tides (D) all of the above,D,"Moving water has energy (Figure 5.10). That energy is used to make electricity. Hydroelectric power harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the worlds electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare. "
Wind power has only been harnessed in recent years.,(A) true (B) false,B,"Wind power has many advantages. It does not burn, so it does not release pollution or carbon dioxide. Also, wind is plentiful in many places. Wind, however, does not blow all of the time, even though power is needed all of the time. Just as with solar power, engineers are working on technologies that can store wind power for later use. Windmills are expensive and wear out quickly. A lot of windmills are needed to power a region, so nearby residents may complain about the loss of a nice view if a wind farm is built. Coastlines typically receive a lot of wind, but wind farms built near beaches may cause unhappiness for local residents and tourists. The Cape Wind project off of Cape Cod, Massachusetts has been approved but is generating much controversy. Opponents are in favor of green power but not at that location. Proponents say that clean energy is needed and the project would supply 75% of the electricity needed for Cape Cod and nearby islands (Figure 1.2). California was an early adopter of wind power. Windmills are found in mountain passes, where the cooler Pacific Ocean air is sucked through on its way to warmer inland valleys. Large fields of windmills can be seen at Altamont Pass in the eastern San Francisco Bay Area, San Gorgonio Pass east of Los Angeles, and Tehachapi Pass at the southern end of the San Joaquin Valley. "
"Generally, to harness the power of water flowing in a stream, the stream must be",(A) drained (B) dammed (C) depleted (D) destroyed,B,"To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy. Water is allowed to flow downhill into a large turbine. While flowing downhill, the water has kinetic energy. Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity. "
The largest geothermal power planet in the United States is in Iceland.,(A) true (B) false,B,"Solar and wind power may get the headlines when it comes to renewable energy. But another type of clean power is heating up in the hills just north of Sonoma wine country. Geothermal power uses heat from deep inside the Earth to generate electricity. The Geysers, the worlds largest power-producing geothermal field, has been providing electricity for roughly 850,000 Northern California households, and is set to expand even further. For more information on geothermal energy, see http://science.kqed.org/quest/video/geothermal-heats-up/ . MEDIA Click image to the left or use the URL below. URL: "
A wind turbine is a device that uses the energy of wind to,(A) grind grain (B) pump water (C) generate electricity (D) all of the above,C,"Wind power uses moving air as a source of energy. Some types of wind power have been around for a long time. People have used windmills to grind grain and pump water for hundreds of years. Sailing ships have depended on wind for millennia. Wind is now used to generate electricity. Moving air can make a turbine spin, just like moving water can. Moving air has kinetic energy. When wind hits the blades of the turbine, the kinetic energy makes the blades move. The turbine spins and creates electricity. "
Which of the following is an advantage of using biofuels?,(A) Growing plants for the fuels uses up carbon dioxide (B) Using the fuels does not produce air pollution (C) Producing the fuels does not require processing (D) all of the above,A,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
"To produce electricity, a resource must somehow turn a turbine.",(A) true (B) false,A,"To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy. Water is allowed to flow downhill into a large turbine. While flowing downhill, the water has kinetic energy. Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity. "
A geothermal power plant generates electricity with,(A) melted rock (B) hot water (C) flowing water (D) wave energy,B,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
The land upstream of a dam may be flooded.,(A) true (B) false,A,"People try to protect areas that might flood with dams, and dams are usually very effective. But high water levels sometimes cause a dam to break and then flooding can be catastrophic. People may also line a river bank with levees, high walls that keep the stream within its banks during floods. A levee in one location may just force the high water up or downstream and cause flooding there. The New Madrid Overflow in the Figure 1.2 was created with the recognition that the Mississippi River sometimes simply cannot be contained by levees and must be allowed to flood. "
Most of Earths energy comes directly or indirectly from the Sun.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
The sun is planet Earths main source of energy.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
Solar energy has been used by people only since the late 1900s.,(A) true (B) false,B,"Solar energy has been used on a small scale for hundreds of years. Today we are using solar energy for more of our power demands. Solar power plants are being built in many locations around the world. In the United States, the southwestern deserts are well suited for solar plants. "
A solar cell consists of many solar panels.,(A) true (B) false,B,"Solar cells convert the energy in sunlight to electrical energy. Solar cells are also called photovoltaic (PV) cells because they use light (photo-) to produce voltage (-voltaic). Solar cells contain a material such as silicon that absorbs light energy. The energy knocks electrons loose so they can flow freely and produce a difference in electric potential energy, or voltage. The flow of electrons creates electric current. Solar cells have positive and negative contacts, like the terminals in chemical cells. If the contacts are connected with wire, current flows from the negative to positive contact. The Figure 1.2 shows how a solar cell works. "
Solar power plants use mirrors to focus sunlight.,(A) true (B) false,A,"Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. "
The technology needed for most uses of solar energy is expensive.,(A) true (B) false,A,"Solar energy has many benefits. It is extremely abundant, widespread, and will never run out. But there are problems with the widespread use of solar power. Sunlight must be present. Solar power is not useful in locations that are often cloudy or dark. However, storage technology is being developed. The technology needed for solar power is still expensive. An increase in interested customers will provide incentive for companies to research and develop new technologies and to figure out how to mass-produce existing technologies (Figure 1.3). Solar panels require a lot of space. Fortunately, solar panels can be placed on any rooftop to supply at least some of the power required for a home or business. This experimental car is one example of the many uses that engineers have found for solar energy. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Streams with wide valleys are best for producing hydroelectric power.,(A) true (B) false,B,"To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy. Water is allowed to flow downhill into a large turbine. While flowing downhill, the water has kinetic energy. Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity. "
Using water power has no negative effects on the environment.,(A) true (B) false,B,"Water power does not burn a fuel. So it causes less pollution than many other kinds of energy. Water power is also a renewable resource. Water keeps flowing downhill. Although we use some of the energy from this movement, we are not using up the water. Water power does have problems. A large dam stops a streams flow, which floods the land upstream. A beautiful location may be lost. People may be displaced. The dams and turbines also change the downstream environment. Fish and other living things may not be able to survive. Dams slow the release of silt. Downstream deltas retreat and beaches may be starved of sand. Seaside cities may become exposed to storms and rising sea levels. Tidal power stations may need to close off a narrow bay or estuary. Wave power plants must withstand coastal storms and the corrosion of seawater. "
Wind turbines are inexpensive and long lasting.,(A) true (B) false,B,"Wind power has many advantages. It is clean: it does not release pollutants or carbon dioxide. It is plentiful almost everywhere. The technology to harness wind energy is being developed rapidly. Wind power also has problems. Wind does not blow all of the time, so wind energy must be stored for later use. Alternatively, another energy source needs to be available when the wind is not blowing. Wind turbines are expensive. They can wear out quickly. Finally, windmills are not welcomed by residents of some locations. They say that they are unattractive. Yet even with these problems, wind turbines are a competitive form of renewable energy. Many states are currently using wind power. Wind turbines are set up in mountain passes. This is common in California, where cool Pacific Ocean air is sucked across the passes and into the warmer inland valleys. "
Some car engines can run on pure vegetable oil.,(A) true (B) false,A,Oil is a liquid fossil fuel that is extremely useful because it can be transported easily and can be used in cars and other vehicles. Oil is currently the single largest source of energy in the world. 
Geothermal energy can be used without processing.,(A) true (B) false,A,"Because the hot water or steam can be used directly to make a turbine spin, geothermal energy can be used without processing. Geothermal energy is clean and safe. It is renewable. There will always be hot rocks and water can be pumped down into a well. There, the water can be heated again to make more steam. Geothermal energy is an excellent resource in some parts of the world. Iceland is gets about one fourth of its electricity from geothermal sources. In the United States, California leads all states in producing geothermal energy. Geothermal energy in California is concentrated in the northern part of the state. The largest plant is in the Geysers Geothermal Resource Area. Geothermal energy is not economical everywhere. Many parts of the world do not have underground sources of heat that are close enough to the surface for building geothermal power plants. "
fuel made from plants,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,C,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
device that changes sunlight directly to electricity,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,G,Solar cells convert the energy in sunlight to electrical energy. They contain a material such as silicon that absorbs light energy and gives off electrons. The electrons flow and create electric current. Figure 23.13 and the animation at the URL below show how a solar cell uses light energy to produce electric current and power a light bulb. Many calculators and other devices are also powered by solar cells. 
transfer of energy between two objects that are in contact,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,A,"Conduction is the transfer of thermal energy between particles of matter that are touching. When energetic particles collide with nearby particles, they transfer some of their thermal energy. From particle to particle, like dominoes falling, thermal energy moves throughout a substance. In Figure 18.5, conduction occurs between particles of the metal in the pot and between particles of the pot and the water. Figure 18.6 shows additional examples of conduction. For a deeper understanding of this method of heat transfer, watch the animation ""Conduction"" at this URL: http://w "
transfer of energy through a liquid by currents,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,D,"Convection is the transfer of thermal energy by particles moving through a fluid. Particles transfer energy by moving from warmer to cooler areas. Thats how energy is transferred in the soup in Figure 18.7. Particles of soup near the bottom of the pot get hot first. They have more energy so they spread out and become less dense. With lower density, these particles rise to the top of the pot (see Figure 18.8). By the time they reach the top of the pot they have cooled off. They have less energy to move apart, so they become denser. With greater density, the particles sink to the bottom of the pot, and the cycle repeats. This loop of moving particles is called a convection current. Convection currents move thermal energy through many fluids, including molten rock inside Earth, water in the oceans, and air in the atmosphere. In the atmosphere, convection currents create wind. You can see one way this happens in Figure 18.9. Land heats up and cools off faster than water because it has lower specific heat. Therefore, land is warmer during the day and cooler at night than water. Air close to the surface gains or loses heat as well. Warm air rises because it is less dense, and when it does, cool air moves in to take its place. This creates a convection current that carries air from the warmer to the cooler area. You can learn more about convection currents by watching ""Convection"" at this URL:  . "
source of the suns energy,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,B,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
transfer of energy by waves that can travel through matter or across space,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,F,"Electromagnetic waves transfer energy across space as well as through matter. They vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves, shown in the Figure 1.1, is called the electromagnetic spectrum. "
electricity produced by harnessing the energy of flowing water,(A) conduction (B) nuclear fusion (C) biofuel (D) convection (E) hydroelectric power (F) radiation (G) solar cell,E,"To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy. Water is allowed to flow downhill into a large turbine. While flowing downhill, the water has kinetic energy. Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity. "
"To develop the theory of plate tectonics, scientists first had to accept the idea that",(A) Earths core consists of molten metals (B) some organisms can cross the oceans (C) Earths continents are able to move (D) all of the above,C,"First, lets review plate tectonics theory. Plate tectonics theory explains why: Earths geography has changed over time and continues to change today. some places are prone to earthquakes while others are not. certain regions may have deadly, mild, or no volcanic eruptions. mountain ranges are located where they are. many ore deposits are located where they are. living and fossil species are found where they are. Plate tectonic motions affect Earths rock cycle, climate, and the evolution of life. "
Mountain ranges located on both side of the Atlantic Ocean,(A) are the same height and width (B) have the same rock types (C) structures and ages (D) c have ancient fossils and coal seams (E) d are just separate mountain ranges,B,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
The idea of continental drift was first proposed in the early,(A) 1700s (B) 1800s (C) 1900s (D) 2000s,C,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
Scientists didnt accept the continental drift idea because,(A) there was almost no evidence for it (B) Wegener was not liked and no one listened to him (C) there were many other ways to explain the evidence (D) none of these,D,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Magnetic minerals in volcanic rock point to,(A) the current north magnetic pole (B) the north magnetic pole at the time they crystallized (C) the north magnetic pole on the adjacent continent (D) none of these,B,"The next breakthrough in the development of the theory of plate tectonics came two decades after Wegeners death. Magnetite crystals are shaped like a tiny bar magnet. As basalt lava cools, the magnetite crystals line up in the magnetic field like tiny magnets. When the lava is completely cooled, the crystals point in the direction of magnetic north pole at the time they form. How do you expect this would help scientists see whether continents had moved or not? As a Wegener supporter, (and someone who is omniscient), you have just learned of a new tool that may help you. A magnetometer is a device capable of measuring the magnetic field intensity. This allows you to look at the magnetic properties of rocks in many locations. First, youre going to look at rocks on land. Which rocks should you seek out for study? "
Evidence for continental drift comes from ancient,(A) magnetic compasses (B) maps of Pangaea (C) coal seams (D) all of the above,C,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Wegeners idea is correctly referred to as,(A) the continental drift hypothesis (B) the continental drift theory (C) the plate tectonics hypothesis (D) the plate tectonics theory,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Wegener observed that the Appalachian Mountains in eastern North America matched mountain ranges in,(A) western North America (B) South America (C) Greenland (D) Africa,C,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
What was Wegeners continental drift idea?,(A) The continents have always been located at their current locations (B) The continents are moving slowly together from their current locations (C) The continents have moved slowly apart to their current locations (D) None of these,C,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
What was Alfred Wegeners role in the development of the theory of plate tectonics?,(A) He proposed the hypothesis of continental drift (B) He provided evidence that continents have moved (C) He identified magnetic evidence for plate tectonics (D) two of the above,D,"Alfred Wegener was an early 20th century German meteorologist. Wegener believed that the continents were once all joined together. He named the supercontinent Pangaea, meaning all earth. Wegener suggested that Pangaea broke up long ago. Since then, the continents have been moving to their current positions. He called his hypothesis continental drift. "
"In Pangaea, the present continent of South America was attached to present-day",(A) Australia (B) Eurasia (C) Africa (D) India,C,"Pangaea was the last supercontinent on Earth. Evidence for the existence of Pangaea was what Alfred Wegener used to create his continental drift hypothesis, which was described in the chapter Plate Tectonics. As the continents move and the land masses change shape, the shape of the oceans changes too. During the time of Pangaea, about 250 million years ago, most of Earths water was collected in a huge ocean called Panthalassa (Figure 1.2). Click image to the left or use the URL below. URL: "
region of magnetic force surrounding a magnet,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,F,"Like the electric field that surrounds a charged particle, a magnetic field surrounds a magnet. This is the area around the magnet where it exerts magnetic force. Figure 24.3 shows the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. To see an animated magnetic field of a bar magnet, go to this URL: http://elgg.norfolk.e2bn.org/jsmith112/files/68/149/ When two magnets are brought close together, their magnetic fields interact. You can see how in Figure 24.4. The drawings show how lines of force of north and south poles attract each other whereas those of two north poles repel each other. The animations at the URL below show how magnetic field lines change as two or more magnets move in relation to each other. You can take an animated quiz to check your understanding of magnetic field interactions at this URL: http://elgg. "
evidence for continental drift identified after Wegeners death,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,C,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
hypothesis that continents move over Earths surface,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,D,"The seafloor spreading hypothesis brought all of these observations together in the early 1960s. Hot mantle material rises up at mid-ocean ridges. The hot magma erupts as lava. The lava cools to form new seafloor. Later, more lava erupts at the ridge. The new lava pushes the seafloor that is at the ridge horizontally away from ridge axis. The seafloor moves! In some places, the oceanic crust comes up to a continent. The moving crust pushes that continent away from the ridge axis as well. If the moving oceanic crust reaches a deep sea trench, the crust sinks into the mantle. The creation and destruction of oceanic crust is the reason that continents move. Seafloor spreading is the mechanism that Wegener was looking for! "
evidence for continental drift identified by Wegener,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,B,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Similar fossil records across continents was evidence for continental drift.,(A) true (B) false,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
former supercontinent that consisted of all the present continents,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,E,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
The magnetic north pole and geographic north pole are in the same location.,(A) true (B) false,B,"Although a compass always points north, it doesnt point to Earths geographic north pole, which is located at 90 north latitude (see Figure 24.11). Instead, it points to Earths magnetic north pole, which is located at about 80 north latitude. Earths magnetic south pole is also located several degrees of latitude away from the geographic south pole. A compass pointer has north and south poles, and its north pole points to Earths magnetic north pole. Why does this happen if opposite poles attract? Why doesnt the compass needle point south instead? The answer may surprise you. Earths magnetic north pole is actually the south pole of magnet Earth! Its called the magnetic north pole to avoid confusion. Because its close to the geographic north pole, it would be confusing to call it the magnetic south pole. "
theory that explains how continents can drift,(A) plate tectonics (B) fossils (C) magnetite crystals (D) continental drift (E) Pangaea (F) magnetic field,A,"How does this help you to provide evidence for continental drift? To test the idea that the pole remained fixed but the continents moved, geologists fitted the continents together as Wegener had done. It worked! There has only been one magnetic north pole and the continents have drifted (Figure 1.4). They named the phenomenon of the magnetic pole that seemed to move but actually did not apparent polar wander. On the left: The apparent north pole for Europe and North America if the continents were always in their current locations. The two paths merge into one if the continents are allowed to drift. This evidence for continental drift gave geologists renewed interest in understanding how continents could move about on the planets surface. "
If an ancient coral reef is found in the arctic it means that the continent it is on has drifted.,(A) true (B) false,A,Coral reefs are found only in warm water. Coal swamps are also found in tropical and subtropical environments. Wegener discovered ancient coal seams and coral reef fossils in areas that are much too cold today. Wegener thought that the continents have moved since the time of Pangaea. 
The continents have never all been together as a single whole continent.,(A) true (B) false,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
The locations of ancient climate zones provide evidence for continental drift.,(A) true (B) false,A,"Wegener also looked at evidence from ancient glaciers. Glaciers are found in very cold climates near the poles. The evidence left by some ancient glaciers is very close to the equator. Wegener knew that this was impossible! However, if the continents had moved, the glaciers would have been centered close to the South Pole. "
The theory of plate tectonics was developed before the idea of continental drift.,(A) true (B) false,B,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
Wegener believed that all the continents were once joined together.,(A) true (B) false,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Wegeners hypothesis of continental drift was widely accepted as soon as it was introduced.,(A) true (B) false,B,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Wegener and his supporters provided a lot of evidence for continental drift.,(A) true (B) false,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
Wegener found rocks of the same type and age on both sides of the Atlantic Ocean.,(A) true (B) false,A,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
Wegener suggested that Pangaea broke up a short time ago.,(A) true (B) false,B,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
Wegener developed a theory to explain how continents can drift.,(A) true (B) false,B,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
The most common stress at divergent plate boundaries is,(A) tension stress (B) compression stress (C) shear stress (D) confining stress,A,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
As a rock experiences more stress it,(A) deforms plastically (B) then elastically (C) then breaks (D) b breaks (E) then deforms plastically (F) then elastically (G) c deforms elastically (H) then plastically (I) then breaks (J) d breaks (K) then deforms elastically (L) then plastically,C,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
Stresses change rock by causing,(A) folds (B) faults (C) fractures (D) all of the above,D,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
"In the Grand Canyon, the Kaibab Limestone is above the Toroweap Formation. We can say that",(A) the Kaibab is the oldest rock layer in the canyon (B) the Toroweap is the oldest rock layer in the canyon (C) the Kaibab is older than the Toroweap (D) the Toroweap is older than the Kaibab,D,"The Grand Canyon provides an excellent illustration of the principles above. The many horizontal layers of sedi- mentary rock illustrate the principle of original horizontality (Figure 1.3). The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition. Distinctive rock layers, such as the Kaibab Limestone, are matched across the broad expanse of the canyon. These rock layers were once connected, as stated by the rule of lateral continuity. The Colorado River cuts through all the layers of rock to form the canyon. Based on the principle of cross- cutting relationships, the river must be younger than all of the rock layers that it cuts through. "
A fold that bends downward is known as a(n),(A) monocline (B) syncline (C) anticline (D) incline,B,"A syncline is a fold that bends downward. The youngest rocks are at the center and the oldest are at the outside (Figure 1.3). When rocks bend downward in a circular structure, that structure is called a basin (Figure 1.4). If the rocks are exposed at the surface, where are the oldest rocks located? Click image to the left or use the URL below. URL:  Anticlines are formations that have folded rocks upward. (a) Schematic of a syncline. (b) This syncline is in Rainbow Basin, California. Some folding can be fairly complicated. What do you see in the photo above? "
"When rocks deform plastically, they tend to",(A) return to their original state (B) fold (C) break (D) fracture,B,"Rocks deforming plastically under compressive stresses crumple into folds. They do not return to their original shape. If the rocks experience more stress, they may undergo more folding or even fracture. You can see three types of folds. "
"In a normal fault,",(A) the fault plane is roughly vertical (B) the dip of the fault plane is nearly horizontal (C) the hanging wall pushes up relative to the footwall (D) the footwall pushes up relative to the hanging wall,D,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
A place where rock breaks but doesnt move it is called a,(A) fold (B) fault (C) joint (D) confinement,C,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
A fracture becomes a fault only if rock,(A) cracks (B) moves (C) folds (D) deforms,B,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
"Large mountain ranges, like the Grand Tetons in Wyoming, are uplifted on",(A) normal faults (B) reverse faults (C) dip-slip faults (D) strike-slip faults,A,"Most of the worlds largest mountains form as plates collide at convergent plate boundaries. Continents are too buoyant to get pushed down into the mantle. So when the plates smash together, the crust crumples upwards. This creates mountains. Folding and faulting in these collision zones makes the crust thicker. The worlds highest mountain range, the Himalayas, is growing as India collides with Eurasia. About 80 million years ago, India was separated from Eurasia by an ocean (Figure 7.16). As the plates collided, pieces of the old seafloor were forced over the Asian continent. This old seafloor is now found high in the Himalayas (Figure 7.17). "
Which statement about the San Andreas fault is false?,(A) It is a transform fault (B) It is a strike-slip fault (C) It occurs at a plate boundary (D) none of the above,D,"The San Andreas Fault in California is a right-lateral strike-slip fault (Figure 7.15). It is also a transform fault because the San Andreas is a plate boundary. As you can see, California will not fall into the ocean someday. The land west of the San Andreas Fault is moving northeastward, while the North American plate moves southwest. Someday, millions of years from now, Los Angeles will be a suburb of San Francisco! "
Most of the worlds largest mountains formed at,(A) convergent plate boundaries (B) divergent plate boundaries (C) transform plate boundaries (D) confining plate boundaries,A,"Most of the worlds largest mountains form as plates collide at convergent plate boundaries. Continents are too buoyant to get pushed down into the mantle. So when the plates smash together, the crust crumples upwards. This creates mountains. Folding and faulting in these collision zones makes the crust thicker. The worlds highest mountain range, the Himalayas, is growing as India collides with Eurasia. About 80 million years ago, India was separated from Eurasia by an ocean (Figure 7.16). As the plates collided, pieces of the old seafloor were forced over the Asian continent. This old seafloor is now found high in the Himalayas (Figure 7.17). "
If very old rocks are above much younger rocks there may be a thrust fault in between.,(A) true (B) false,A,"With enough stress, a rock will fracture, or break. The fracture is called a joint if the rock breaks but doesnt move, as shown in Figure 7.10. If the rocks on one or both sides of a fracture move, the fracture is called a fault (Figure 7.11). Faults can occur alone or in clusters, creating a fault zone. Earthquakes happen when rocks break and move suddenly. The energy released causes an earthquake. Slip is the distance rocks move along a fault, as one block of rock moves past the other. The angle of a fault is called When compression squeezes the crust into a smaller space, the hanging wall pushes up relative to the footwall. This creates a reverse fault. A thrust fault is a type of reverse fault where the angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 7.13). "
A deeply buried rock is under compressive stresses.,(A) true (B) false,A,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
The terrain known as basin-and-range is caused by compressive forces.,(A) true (B) false,B,"Amazingly, even divergence can create mountain ranges. When tensional stresses pull crust apart, it breaks into blocks that slide up and drop down along normal faults. The result is alternating mountains and valleys, known as a basin-and-range (Figure 1.3). In basin-and-range, some blocks are uplifted to form ranges, known as horsts, and some are down-dropped to form basins, known as grabens. (a) Horsts and grabens. (b) Mountains in Nevada are of classic basin-and-range form. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
The amount the ground moves in an earthquake is called slip.,(A) true (B) false,A,"If the blocks of rock on one or both sides of a fracture move, the fracture is called a fault (Figure 1.2). Stresses along faults cause rocks to break and move suddenly. The energy released is an earthquake. How do you know theres a fault in this rock? Try to line up the same type of rock on either side of the lines that cut across them. One side moved relative to the other side, so you know the lines are a fault. Slip is the distance rocks move along a fault. Slip can be up or down the fault plane. Slip is relative, because there is usually no way to know whether both sides moved or only one. Faults lie at an angle to the horizontal surface of the Earth. That angle is called the faults dip. The dip defines which of two basic types a fault is. If the faults dip is inclined relative to the horizontal, the fault is a dip-slip fault (Figure 1.3). "
"In a strike-slip fault, the dip of the fault plane is vertical.",(A) true (B) false,A,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
Any force applied to rock is a stress.,(A) true (B) false,A,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
"When confining stress occurs, rock deforms.",(A) true (B) false,B,"Stress is the force applied to a rock. There are four types of stresses: Confining stress happens as weight of all the overlying rock pushes down on a deeply buried rock. The rock is being pushed in from all sides, which compresses it. The rock will not deform because there is no place for it to move. Compression stress squeezes rocks together. Compression causes rocks to fold or fracture (Figure 7.1). When two cars collide, compression causes them to crumple. Compression is the most common stress at convergent plate boundaries. Tension stress pulls rocks apart. Tension causes rocks to lengthen or break apart. Tension is the major type of stress found at divergent plate boundaries. Shear stress happens when forces slide past each other in opposite directions (Figure 7.2). This is the most common stress found at transform plate boundaries. The amount of stress on a rock may be greater than the rocks strength. In that case, the rock will change and deform (Figure 7.3). Deep within the Earth, the pressure is very great. A rock behaves like a stretched rubber band. When the stress stops, the rock goes back to its original shape. If more stress is applied to the rock, it bends and flows. It does not return to its original shape. Near the surface, if the stress continues, the rock will fracture and break. "
Compression is the most common stress at convergent plates.,(A) true (B) false,A,"Stress is the force applied to a rock. There are four types of stresses: Confining stress happens as weight of all the overlying rock pushes down on a deeply buried rock. The rock is being pushed in from all sides, which compresses it. The rock will not deform because there is no place for it to move. Compression stress squeezes rocks together. Compression causes rocks to fold or fracture (Figure 7.1). When two cars collide, compression causes them to crumple. Compression is the most common stress at convergent plate boundaries. Tension stress pulls rocks apart. Tension causes rocks to lengthen or break apart. Tension is the major type of stress found at divergent plate boundaries. Shear stress happens when forces slide past each other in opposite directions (Figure 7.2). This is the most common stress found at transform plate boundaries. The amount of stress on a rock may be greater than the rocks strength. In that case, the rock will change and deform (Figure 7.3). Deep within the Earth, the pressure is very great. A rock behaves like a stretched rubber band. When the stress stops, the rock goes back to its original shape. If more stress is applied to the rock, it bends and flows. It does not return to its original shape. Near the surface, if the stress continues, the rock will fracture and break. "
Stress is the cause of joints in rock.,(A) true (B) false,A,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
A syncline is a fold that arches upward.,(A) true (B) false,B,"A syncline is a fold that bends downward. The youngest rocks are at the center and the oldest are at the outside (Figure 1.3). When rocks bend downward in a circular structure, that structure is called a basin (Figure 1.4). If the rocks are exposed at the surface, where are the oldest rocks located? Click image to the left or use the URL below. URL:  Anticlines are formations that have folded rocks upward. (a) Schematic of a syncline. (b) This syncline is in Rainbow Basin, California. Some folding can be fairly complicated. What do you see in the photo above? "
An area where faults are clustered is called a fault zone.,(A) true (B) false,A,"With enough stress, a rock will fracture, or break. The fracture is called a joint if the rock breaks but doesnt move, as shown in Figure 7.10. If the rocks on one or both sides of a fracture move, the fracture is called a fault (Figure 7.11). Faults can occur alone or in clusters, creating a fault zone. Earthquakes happen when rocks break and move suddenly. The energy released causes an earthquake. Slip is the distance rocks move along a fault, as one block of rock moves past the other. The angle of a fault is called When compression squeezes the crust into a smaller space, the hanging wall pushes up relative to the footwall. This creates a reverse fault. A thrust fault is a type of reverse fault where the angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 7.13). "
Movement of rock at faults is the cause of earthquakes.,(A) true (B) false,A,"With enough stress, a rock will fracture, or break. The fracture is called a joint if the rock breaks but doesnt move, as shown in Figure 7.10. If the rocks on one or both sides of a fracture move, the fracture is called a fault (Figure 7.11). Faults can occur alone or in clusters, creating a fault zone. Earthquakes happen when rocks break and move suddenly. The energy released causes an earthquake. Slip is the distance rocks move along a fault, as one block of rock moves past the other. The angle of a fault is called When compression squeezes the crust into a smaller space, the hanging wall pushes up relative to the footwall. This creates a reverse fault. A thrust fault is a type of reverse fault where the angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 7.13). "
Normal faults are caused by compression stress.,(A) true (B) false,B,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
Strike-slip faults result from shear stress.,(A) true (B) false,A,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
Only the process of folding creates mountain ranges.,(A) true (B) false,B,"Many processes create mountains. Most mountains form along plate boundaries. A few mountains may form in the middle of a plate. For example, huge volcanoes are mountains formed at hotspots within the Pacific Plate. "
fault in which the hanging wall drops down relative to the footwall,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,B,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
block of rock that is beneath a dip-slip fault plane,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,G,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
fault in which the hanging wall pushes up relative to the footwall,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,C,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
block of rock that is above a dip-slip fault plane,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,F,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
fault with a fault plane that is not vertical,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,A,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
fault with a vertical fault plane,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,D,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
reverse fault in which the fault plane is nearly horizontal,(A) dip-slip fault (B) normal fault (C) reverse fault (D) strike-slip fault (E) thrust fault (F) hanging wall (G) footwall,E,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
When lava is thick it,(A) travels far from vents (B) forms a caldera (C) flows rapidly (D) none of the above,D,"When lava is thick, it flows slowly. If thick lava makes it to the surface, it cannot flow far from the vent. It often stays right in the middle of a crater at the top of a volcano. Here the lava creates a large, round lava dome (Figure "
Lava that flows from vents at mid-ocean ridges,(A) forms composite volcanoes (B) creates lava plateaus (C) creates lava domes (D) is thin and runny,D,"Remember that the mid-ocean ridge is where hot mantle material upwells in a convection cell. The upwelling mantle melts due to pressure release to form lava. Lava flows at the surface cool rapidly to become basalt, but deeper in the crust, magma cools more slowly to form gabbro. The entire ridge system is made up of igneous rock that is either extrusive or intrusive. The seafloor is also igneous rock with some sediment that has fallen onto it. Earthquakes are common at mid-ocean ridges since the movement of magma and oceanic crust results in crustal shaking. Click image to the left or use the URL below. URL: "
Examples of lava plateaus include the,(A) ocean basins (B) Columbia Plateau (C) Hawaiian Islands (D) two of the above,B,"A lava plateau is made of a large amount of fluid lava. The lava flows over a large area and cools. This creates a large, flat surface of igneous rock. Lava plateaus may be huge. The Columbia Plateau covers over 161,000 square kilometers (63,000 square miles). It makes up parts of the states of Washington, Oregon, and Idaho. Thin, fluid lava created the rock that makes up the entire ocean floor. This is from multiple eruptions from vents at the mid-ocean ridge. While not exactly a lava plateau, its interesting to think about so much lava! "
An intrusion forms when,(A) a volcano erupts (B) magma cools underground (C) lava hardens at the surface (D) lava is very thin,B,Magma that cools underground forms intrusions (Figure 8.22). Intrusions become land formations if they are exposed at the surface by erosion. 
Which statement about hot springs is false?,(A) They are very rare (B) They are found in Antarctica (C) They are used as natural hot tubs (D) They are thought to cure illnesses,A,"Water heated below ground that rises through a crack to the surface creates a hot spring. The water in hot springs may reach temperatures in the hundreds of degrees Celsius beneath the surface, although most hot springs are much cooler. Click image to the left or use the URL below. URL: "
A geyser forms when underground water is,(A) superheated (B) under pressure (C) trapped in a narrow passage (D) all of the above,D,"Heated groundwater may become trapped in spaces within rocks. Pressure builds up as more water seeps into the spaces. When the pressure becomes great enough, the water bursts out of the ground at a crack or weak spot. This is called a geyser. When the water erupts from the ground, the pressure is released. Then more water collects and the pressure builds up again. This leads to another eruption. Old Faithful is the best-known geyser in the world. You can see a picture of it in Figure 13.17. The geyser erupts faithfully every 90 minutes, day after day. During each eruption, it may release as much as 30,000 liters of water! "
Which statement about geysers is false?,(A) There are only about 1000 geysers in the world (B) About half the worlds geysers are in the US (C) The water in geysers is heated by magma (D) All geysers erupt on a regular schedule,D,"Geysers are also created by water that is heated beneath the Earths surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser. There are only a few areas in the world where the conditions are right for the formation of geysers. Only about 1,000 geysers exist worldwide. About half of them are in the United States. The most famous geyser is Old Faithful at Yellowstone National Park (Figure 8.23). It is rare for a geyser to erupt so regularly, which is why Old Faithful is famous. "
hot water that seeps out of a crack at the surface,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,E,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
igneous rock formation that results when lava cools in the middle of a volcanic crater,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,C,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
hot water under pressure that forcefully erupts out of the surface,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,F,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
type of igneous rock that forms when magma cools below Earths surface,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,B,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
type of igneous rock that forms when lava cools on Earths surface,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,A,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
flat surface of igneous rock that forms when thin lava flows over a large area,(A) extrusive igneous rock (B) intrusive igneous rock (C) lava dome (D) lava plateau (E) hot spring (F) geyser,D,"A lava plateau forms when large amounts of fluid lava flow over an extensive area (Figure 1.4). When the lava solidifies, it creates a large, flat surface of igneous rock. Layer upon layer of basalt have created the Columbia Plateau, which covers more than 161,000 square kilometers (63,000 square miles) in Washington, Oregon, and Idaho. "
Intrusive igneous rocks are never visible on Earths surface.,(A) true (B) false,B,Extrusive igneous rocks cool at the surface. Volcanoes are one type of feature that forms from extrusive rocks. Several other interesting landforms are also extrusive features. Intrusive igneous rocks cool below the surface. These rocks do not always remain hidden. Rocks that formed in the crust are exposed when the rock and sediment that covers them is eroded away. 
A lava dome is any mountain that forms from lava.,(A) true (B) false,B,"Viscous lava flows slowly. If there is not enough magma or enough pressure to create an explosive eruption, the magma may form a lava dome. Because it is so thick, the lava does not flow far from the vent. (Figure 1.2). Lava flows often make mounds right in the middle of craters at the top of volcanoes, as seen in the Figure 1.3. A fissure eruption on Mauna Loa in Hawaii travels toward Mauna Kea on the Big Is- land. Lava domes are large, round landforms created by thick lava that does not travel far from the vent. Lava domes may form in the crater of composite volcanoes as at Mount St. He- lens. "
The lava that forms a lava dome is thin and runny.,(A) true (B) false,B,"Viscous lava flows slowly. If there is not enough magma or enough pressure to create an explosive eruption, the magma may form a lava dome. Because it is so thick, the lava does not flow far from the vent. (Figure 1.2). Lava flows often make mounds right in the middle of craters at the top of volcanoes, as seen in the Figure 1.3. A fissure eruption on Mauna Loa in Hawaii travels toward Mauna Kea on the Big Is- land. Lava domes are large, round landforms created by thick lava that does not travel far from the vent. Lava domes may form in the crater of composite volcanoes as at Mount St. He- lens. "
A lava plateau forms when a volcano produces very little lava.,(A) true (B) false,B,"A lava plateau forms when large amounts of fluid lava flow over an extensive area (Figure 1.4). When the lava solidifies, it creates a large, flat surface of igneous rock. Layer upon layer of basalt have created the Columbia Plateau, which covers more than 161,000 square kilometers (63,000 square miles) in Washington, Oregon, and Idaho. "
Lava from shield volcanoes created the Hawaiian Islands.,(A) true (B) false,A,New land is created in volcanic eruptions. The Hawaiian Islands are shield volcanoes. These volcanoes formed from fluid lava (Figure 8.21). The island grows as lava is added on the coast. New land may also emerge from lava that erupts from beneath the water. This is one way that new land is created. 
Intrusions form on the surface and later are buried by sediments.,(A) true (B) false,B,Magma that cools underground forms intrusions (Figure 8.22). Intrusions become land formations if they are exposed at the surface by erosion. 
The water in hot springs is heated by magma.,(A) true (B) false,A,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
Sediments produced by weathering include,(A) boulders (B) gravel (C) silt (D) all of the above,D,"Weathering changes solid rock into sediments. Sediments are different sizes of rock particles. Boulders are sedi- ments; so is gravel. At the other end, silt and clay are also sediments. Weathering causes rocks at the Earths surface to change form. The new minerals that form are stable at the Earths surface. It takes a long time for a rock or mountain to weather. But a road can do so much more quickly. If you live in a part of the world that has cold winters, you may only have to wait one year to see a new road start to weather (Figure "
"If pieces of a rock flake off due to extreme temperature differences, it would be",(A) erosion (B) mechanical weathering (C) chemical weathering (D) transportation,B,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
What is the first step in the process of ice wedging?,(A) Ice melts in cracks in rocks (B) Water freezes in cracks in rocks (C) Water seeps into cracks in rocks (D) Ice wedges apart cracks in rocks,C,"There are many ways that rocks can be broken apart into smaller pieces. Ice wedging is the main form of mechanical weathering in any climate that regularly cycles above and below the freezing point (Figure 1.1). Ice wedging works quickly, breaking apart rocks in areas with temperatures that cycle above and below freezing in the day and night, and also that cycle above and below freezing with the seasons. Ice wedging breaks apart so much rock that large piles of broken rock are seen at the base of a hillside, as rock fragments separate and tumble down. Ice wedging is common in Earths polar regions and mid latitudes, and also at higher elevations, such as in the mountains. "
Chemical weathering,(A) is unrelated to mechanical weathering (B) can go faster when there has been mechanical weathering (C) is slowed down after there has been mechanical weathering (D) none of these,B,"Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. There are many agents of chemical weathering. Remember that water was a main agent of mechanical weathering. Well, water is also an agent of chemical weathering. That makes it a double agent! Carbon dioxide and oxygen are also agents of chemical weathering. Each of these is discussed below. "
Abrasion may be caused by all of the following except,(A) gravity (B) glaciers (C) moving water (D) carbon dioxide,D,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
If a mineral changes to a different type it has experienced,(A) erosion (B) physical weathering (C) chemical weathering (D) transportation,C,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
Minerals undergo chemical weathering because,(A) they formed at different pressure and temperature (B) they first undergo mechanical weathering (C) they break apart by mechanical weathering (D) water takes away some of their ions,A,"Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. There are many agents of chemical weathering. Remember that water was a main agent of mechanical weathering. Well, water is also an agent of chemical weathering. That makes it a double agent! Carbon dioxide and oxygen are also agents of chemical weathering. Each of these is discussed below. "
Plants can cause,(A) mechanical weathering (B) chemical weathering (C) ice wedging (D) two of the above,D,"Plants dont have an immune system, but they do respond to disease. Typically, their first line of defense is the death of cells surrounding infected tissue. This prevents the infection from spreading. Many plants also produce hormones and toxins to fight pathogens. For example, willow trees, like the one in Figure Exciting new research suggests that plants may even produce chemicals that warn other, nearby plants of threats to their health. The warnings allow nearby plants to prepare for their own defense. As these and other responses show, plants may be rooted in place, but they are far from helpless. "
How does mechanical weathering increase the rate of chemical weathering?,(A) It makes rocks softer (B) It changes the minerals in rocks (C) It increases the surface area of rocks (D) all of the above,C,"Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases Figure 1.5. With more surfaces exposed, there are more surfaces on which chemical weathering can occur. Mechanical weathering may increase the rate of chemical weathering. Click image to the left or use the URL below. URL: "
Because carbon dioxide combines with water in the atmosphere,(A) average global temperatures are rising (B) plants die off (C) the atmosphere is warmer (D) rainwater is a weak acid,D,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
Agents of chemical weathering include all of the following except,(A) ice (B) water (C) nitric acid (D) sulfuric acid,A,"Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. There are many agents of chemical weathering. Remember that water was a main agent of mechanical weathering. Well, water is also an agent of chemical weathering. That makes it a double agent! Carbon dioxide and oxygen are also agents of chemical weathering. Each of these is discussed below. "
Which rock weathers quickly?,(A) basalt (B) granite (C) limestone (D) none of the above,C,"Different rock types weather at different rates. Certain types of rock are very resistant to weathering. Igneous rocks, especially intrusive igneous rocks such as granite, weather slowly because it is hard for water to penetrate them. Other types of rock, such as limestone, are easily weathered because they dissolve in weak acids. Rocks that resist weathering remain at the surface and form ridges or hills. Shiprock in New Mexico is the throat of a volcano thats left after the rest of the volcano eroded away. The rock thats left behind is magma that cooled relatively slowly and is harder than the rock that had surrounded it. Different minerals also weather at different rates. Some minerals in a rock might completely dissolve in water, but the more resistant minerals remain. In this case, the rocks surface becomes pitted and rough. When a less resistant mineral dissolves, more resistant mineral grains are released from the rock. A beautiful example of this effect is the ""Stone Forest"" in China, see the video below: The Shiprock formation in northwest New Mexico is the central plug of resistant lava from which the surrounding rock weath- ered and eroded away. Click image to the left or use the URL below. URL: "
agent of chemical weathering,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,B,"Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. There are many agents of chemical weathering. Remember that water was a main agent of mechanical weathering. Well, water is also an agent of chemical weathering. That makes it a double agent! Carbon dioxide and oxygen are also agents of chemical weathering. Each of these is discussed below. "
weathering process that occurs when water freezes in cracks in rocks,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,G,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
weathering process that occurs when rocks and rock particles scrape other rocks,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,C,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
"Important agents of chemical weathering include oxygen, carbon dioxide and sulfur.",(A) true (B) false,A,"Now that you know what chemical weathering is, can you think of some other ways chemical weathering might occur? Chemical weathering can also be contributed to by plants and animals. As plant roots take in soluble ions as nutrients, certain elements are exchanged. Plant roots and bacterial decay use carbon dioxide in the process of respiration. "
rock particle created by weathering,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,E,"Weathering changes solid rock into sediments. Sediments are different sizes of rock particles. Boulders are sedi- ments; so is gravel. At the other end, silt and clay are also sediments. Weathering causes rocks at the Earths surface to change form. The new minerals that form are stable at the Earths surface. It takes a long time for a rock or mountain to weather. But a road can do so much more quickly. If you live in a part of the world that has cold winters, you may only have to wait one year to see a new road start to weather (Figure "
"If temperature increases by 10C, the rate of chemical reactions will double.",(A) true (B) false,A,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. They are more likely to bump into one another and to collide with greater force. For example, when you fry an egg, turning up the heat causes the egg to cook faster. The same principle explains why storing food in a cold refrigerator reduces the rate at which food spoils (see Figure 8.16). Both food frying and food spoiling are chemical reactions that happen faster at higher temperatures. "
type of weathering that breaks rock into smaller pieces,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,D,"Mechanical weathering (also called physical weathering) breaks rock into smaller pieces. These smaller pieces are just like the bigger rock, but smaller. That means the rock has changed physically without changing its composition. The smaller pieces have the same minerals, in just the same proportions as the original rock. "
movement of weathered rock particles,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,F,"Weathering wears rocks at the Earths surface down into smaller pieces. The small fragments are called sediments. Running water, ice, and gravity all transport these sediments from one place to another by erosion. During sedimen- tation, the sediments are laid down or deposited. In order to form a sedimentary rock, the accumulated sediment must become compacted and cemented together. "
All rocks weather at the same rate.,(A) true (B) false,B,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
type of weathering that changes the minerals in rock,(A) chemical weathering (B) carbonic acid (C) abrasion (D) mechanical weathering (E) sediment (F) erosion (G) ice wedging,A,"Chemical weathering is the other important type of weathering. Chemical weathering may change the size of pieces of rock materials, but definitely changes the composition. So one type of mineral changes into a different mineral. Chemical weathering works through chemical reactions that cause changes in the minerals. "
Abrasion is a type of chemical weathering.,(A) true (B) false,B,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
Water can dissolve salt.,(A) true (B) false,A,"Not only salt, but many other solutes can dissolve in water. In fact, so many solutes can dissolve in water that water has been called the universal solvent. Even rocks can dissolve in water, which explains the cave that opened this article. A solute that can dissolve in a given solvent, such as water, is said to be soluble in that solvent. Conversely, a solute that cannot dissolve in a given solvent is said to be insoluble in that solvent. Although most solutes can dissolve in water, some solutes are insoluble in water. Oil is an example. Did you ever try to mix oil with water? No matter how well you mix the oil into the water, after the mixture stands for a while, the oil separates from the water and rises to the top. You can see how oil floats on ocean water in the Figure 1.2. "
Natural weathering is usually a very slow process.,(A) true (B) false,A,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
Grains of sands are weathered particles of rock.,(A) true (B) false,A,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
Agents of mechanical weathering include wind and gravity.,(A) true (B) false,A,"Mechanical weathering breaks rock into smaller pieces. These smaller pieces are just like the bigger rock; they are just smaller! The rock has broken without changing its composition. The smaller pieces have the same minerals in the same proportions. You could use the expression a chip off the old block to describe mechanical weathering! The main agents of mechanical weathering are water, ice, and wind. "
Ice wedging occurs only in extremely cold climates.,(A) true (B) false,B,"Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) "
Pebbles in a stream are worn smooth by abrasion.,(A) true (B) false,A,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
Burrowing animals cause mechanical weathering.,(A) true (B) false,A,"Sometimes biological elements cause mechanical weathering. This can happen slowly. A plants roots grow into a crack in rock. As the roots grow larger, they wedge open the crack. Burrowing animals can also cause weathering. By digging for food or creating a hole to live in the animal may break apart rock. Today, human beings do a lot of mechanical weathering whenever we dig or blast into rock. This is common when we build homes, roads, and subways, or quarry stone for construction or other uses. "
Only acids can dissolve rocks.,(A) true (B) false,B,"Carbon dioxide (CO2 ) combines with water as raindrops fall through the air. This makes a weak acid, called carbonic acid. This happens so often that carbonic acid is a common, weak acid found in nature. This acid works to dissolve rock. It eats away at sculptures and monuments. While this is normal, more acids are made when we add pollutants to the air. Any time we burn any fossil fuel, it adds nitrous oxide to the air. When we burn coal rich in sulfur, it adds sulfur dioxide to the air. As nitrous oxide and sulfur dioxide react with water, they form nitric acid and sulfuric acid. These are the two main components of acid rain. Acid rain accelerates chemical weathering. "
Carbon dioxide makes a weak acid when it combines with oxygen in the air.,(A) true (B) false,B,"Carbon dioxide (CO2 ) combines with water as raindrops fall through the air. This makes a weak acid, called carbonic acid. This happens so often that carbonic acid is a common, weak acid found in nature. This acid works to dissolve rock. It eats away at sculptures and monuments. While this is normal, more acids are made when we add pollutants to the air. Any time we burn any fossil fuel, it adds nitrous oxide to the air. When we burn coal rich in sulfur, it adds sulfur dioxide to the air. As nitrous oxide and sulfur dioxide react with water, they form nitric acid and sulfuric acid. These are the two main components of acid rain. Acid rain accelerates chemical weathering. "
Water is an agent of both mechanical and chemical weathering.,(A) true (B) false,A,"Chemical weathering is different than mechanical weathering. The minerals in the rock change. The rock changes composition and becomes a different type of rock. Most minerals form at high pressure or high temperatures deep within Earth. But at Earths surface, temperatures and pressures are much lower. Minerals that were stable deeper in the crust are not stable at the surface. Thats why chemical weathering happens. Minerals that formed at higher temperature and pressure change into minerals that are stable at the surface. Chemical weathering is important. It starts the process of changing solid rock into soil. We need soil to grow food and create other materials we need. Chemical weathering works through chemical reactions that change the rock. There are many agents of chemical weathering. Remember that water was a main agent of mechanical weathering. Well, water is also an agent of chemical weathering. That makes it a double agent! Carbon dioxide and oxygen are also agents of chemical weathering. Each of these is discussed below. "
All rocks weather at the same rate.,(A) true (B) false,B,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
acid rain is caused by ___________ combining with __________ to form __________.,(A) Ozone; carbon dioxide; carbonic acid (B) Mercury and Iron; water vapor; mercuric and ferrous acids (C) Sulfur and nitrogen oxides; water vapor; sulfuric and nitric acids (D) All of the above,C,"Acid rain is caused by sulfur and nitrogen oxides emanating from power plants or metal refineries. The smokestacks have been built tall so that pollutants dont sit over cities (Figure 1.1). As they move, these pollutants combine with water vapor to form sulfuric and nitric acids. The acid droplets form acid fog, rain, snow, or they may be deposited dry. Most typical is acid rain (Figure 1.2). "
a ph scale has numbers from __________ to __________. neutral is the number __________.,(A) 1; 14; 7 (B) 1; 10; 5 (C) 1; 100; 50 (D) 1: 28; 14,A,"The strength of acids and bases is measured on a scale called the pH scale (see Figure 10.10). The symbol pH represents acidity, or the concentration of hydrogen ions (H+ ) in a solution. Pure water, which is neutral, has a pH of 7. With a higher concentration of hydrogen ions, a solution is more acidic but has a lower pH. Therefore, acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. You can watch a video about the pH scale at this URL:  MEDIA Click image to the left or use the URL below. URL: "
natural rain has a ph of _________________.,(A) 40 (B) 56 (C) 70 (D) 86,B,"Acid rain water is more acidic than normal rain water. Acidity is measured on the pH scale. Lower numbers are more acidic and higher numbers are less acidic (also called more alkaline) (Figure 1.3). Natural rain is somewhat acidic, with a pH of 5.6; acid rain must have a pH of less than 5.0. A small change in pH represents a large change in acidity: rain with a pH of 4.6 is 10 times more acidic than normal rain (with a pH of 5.6). Rain with a pH of 3.6 is 100 times more acidic. Regions with a lot of coal-burning power plants have the most acidic rain. The acidity of average rainwater in the northeastern United States has fallen to between 4.0 and 4.6. Acid fog has even lower pH with an average of around 3.4. One fog in Southern California in 1986 had a pH of 1.7, equal to toilet-bowl cleaner. In arid climates, such as in Southern California, acids deposit on the ground dry. Acid precipitation ends up on the land surface and in water bodies. Some forest soils in the northeast are five to ten times more acidic than they were two or three decades ago. Acid droplets move down through acidic soils to lower the pH of streams and lakes even more. Acids strip soil of metals and nutrients, which collect in streams and lakes. As a result, stripped soils may no longer provide the nutrients that native plants need. A pH scale goes from 1 to 14; numbers are shown with the pH of some common substances. A value of 7 is neutral. The strongest acids are at the low end of the scale and the strongest bases are at the high end. "
a liquid with a ph of 2.0 is __________ more acidic than one with a ph of 4.0.,(A) Two times (B) Ten times (C) 100 times (D) 200 times,C,"The strength of acids and bases is measured on a scale called the pH scale, which is shown in the Figure 1.1. By definition, pH represents the acidity, or hydrogen ion (H+ ) concentration, of a solution. Pure water, which is neutral, has a pH of 7. With a higher the concentration of hydrogen ions, a solution is more acidic and has a lower pH. Acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. Its important to realize that the pH scale is based on powers of ten. For example, a solution with a pH of 8 is 10 times more basic than a solution with a pH of 7, and a solution with a pH of 9 is 100 times more basic than a solution with a pH of 7. Q: How much more acidic is a solution with a pH of 4 than a solution with a pH of 7? A: A solution with a pH of 4 is 1000 (10  10  10, or 103 ) times more acidic than a solution with a pH of 7. Q: Which solution on the pH scale in the Figure 1.1 is the weakest acid? Which solution is the strongest base? A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14. "
"pollutants emitted from tall smokestacks cause problems because they can create acid rain far from where they were released, in other states or nations.",(A) True (B) False,A,"Acid rain is caused by sulfur and nitrogen oxides emanating from power plants or metal refineries. The smokestacks have been built tall so that pollutants dont sit over cities (Figure 1.1). As they move, these pollutants combine with water vapor to form sulfuric and nitric acids. The acid droplets form acid fog, rain, snow, or they may be deposited dry. Most typical is acid rain (Figure 1.2). "
these types of rocks neutralize acids.,(A) Granite (B) Shale (C) Sandstone (D) Limestone,D,"Carbon dioxide (CO2 ) combines with water as raindrops fall through the air. This makes a weak acid, called carbonic acid. This happens so often that carbonic acid is a common, weak acid found in nature. This acid works to dissolve rock. It eats away at sculptures and monuments. While this is normal, more acids are made when we add pollutants to the air. Any time we burn any fossil fuel, it adds nitrous oxide to the air. When we burn coal rich in sulfur, it adds sulfur dioxide to the air. As nitrous oxide and sulfur dioxide react with water, they form nitric acid and sulfuric acid. These are the two main components of acid rain. Acid rain accelerates chemical weathering. "
a big problem crops up when acid rain falls in countries that did not produce it.,(A) True (B) False,A,"Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. If acid rain falls into lakes, it lowers the pH of the water and may kill aquatic organisms. If it falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may make them sick or even kill them. Acid rain also damages stone buildings, bridges, and statues, like the one in Figure 25.1. "
poor nations,(A) May experience crop damage that they can’t control (B) Are not affected by acid rain because they do not have many power plants (C) Have learned to throw limestone on acid soil to help plants grow (D) All of these,A,"Rich nations use more natural resources than poor nations. In fact, the richest 20 percent of people use 85 percent of the worlds resources. What about the poorest 20 percent of people? They use only 1 percent of the worlds resources. You can see this unequal distribution of oil resources in Figure 20.3. Imagine a world in which everybody had equal access to resources. Some people would have fewer resources than they do now. But many people would have more. In the real world, the difference between rich and poor just keeps growing. "
how are songbirds affected by acid rain?,(A) They are killed when the rain touches their feathers (B) They do not thrive because their food sources die in the acid soils (C) Their eggshells become so thick that the young can’t get out (D) All of these,B,"Acid rain takes a toll on ecosystems (Figure 1.4). Plants that are exposed to acids become weak and are more likely to be damaged by bad weather, insect pests, or disease. Snails die in acid soils, so songbirds do not have as much food to eat. Young birds and mammals do not build bones as well and may not be as strong. Eggshells may also be weak and break more easily. As lakes become acidic, organisms die off. No fish can live if the pH drops below 4.5. Organic material cannot decay, and mosses take over the lake. Wildlife that depend on the lake for drinking water suffer population declines. Crops are damaged by acid rain. This is most noticeable in poor nations where people cant afford to fix the problems with fertilizers or other technology. Acid rain has killed trees in this forest in the Czech Republic. Acid rain damages cultural monuments like buildings and statues. These include the U.S. Capitol and many buildings in Europe, such as Westminster Abbey. Carbonate rocks neutralize acids and so some regions do not suffer the effects of acid rain nearly as much. Limestone in the midwestern United States protects the area. One reason that the northeastern United States is so vulnerable to acid rain damage is that the rocks are not carbonates. Because pollutants can travel so far, much of the acid rain that falls hurts states or nations other than ones where the pollutants were released. All the rain that falls in Sweden is acidic and fish in lakes all over the country are dying. The pollutants come from the United Kingdom and Western Europe, which are now working to decrease their emissions. Canada also suffers from acid rain that originates in the United States, a problem that is also improving. Southeast Asia is experiencing more acid rain between nations as the region industrializes. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
arid regions do not get enough rain to have problems with acid rain.,(A) True (B) False,B,"Acid rain takes a toll on ecosystems (Figure 1.4). Plants that are exposed to acids become weak and are more likely to be damaged by bad weather, insect pests, or disease. Snails die in acid soils, so songbirds do not have as much food to eat. Young birds and mammals do not build bones as well and may not be as strong. Eggshells may also be weak and break more easily. As lakes become acidic, organisms die off. No fish can live if the pH drops below 4.5. Organic material cannot decay, and mosses take over the lake. Wildlife that depend on the lake for drinking water suffer population declines. Crops are damaged by acid rain. This is most noticeable in poor nations where people cant afford to fix the problems with fertilizers or other technology. Acid rain has killed trees in this forest in the Czech Republic. Acid rain damages cultural monuments like buildings and statues. These include the U.S. Capitol and many buildings in Europe, such as Westminster Abbey. Carbonate rocks neutralize acids and so some regions do not suffer the effects of acid rain nearly as much. Limestone in the midwestern United States protects the area. One reason that the northeastern United States is so vulnerable to acid rain damage is that the rocks are not carbonates. Because pollutants can travel so far, much of the acid rain that falls hurts states or nations other than ones where the pollutants were released. All the rain that falls in Sweden is acidic and fish in lakes all over the country are dying. The pollutants come from the United Kingdom and Western Europe, which are now working to decrease their emissions. Canada also suffers from acid rain that originates in the United States, a problem that is also improving. Southeast Asia is experiencing more acid rain between nations as the region industrializes. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
a mutation can be:,(A) Beneficial (B) Harmful (C) Neutral (D) Any of the above,D,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
"if a region has brown sand and the mice are all brown, if a white mouse is born it",(A) Means that there is a gene or genes for white fur in the population (B) Probably will not survive to reproduce (C) Will be favored if white sand blows in and covers the brown sand (D) All of the above,D,"There are variations in the traits of a population. For example, there are lots of variations in the color of human hair. Hair can be blonde, brown, black, or even red. Hair color is a trait determined by genes. "
changes in genetic makeup of species over time is known as biological evolution.,(A) True (B) False,A,"Many changes in the genetic makeup of a species may accumulate over time, especially if the environment is changing. Eventually the descendants will be very different from their ancestors and may become a whole new species. Changes in the genetic makeup of a species over time are known as biological evolution. "
the mechanism for evolution is natural selection.,(A) True (B) False,A,"The mechanism for evolution is natural selection. Traits become more or less common in a population depending on whether they are beneficial or harmful. An example of evolution by natural selection can be found in the deer mouse, species Peromyscus maniculatus. In Nebraska this mouse is typically brown, but after glaciers carried lighter sand over the darker soil in the Sand Hills, predators could more easily spot the dark mice. Natural selection favored the light mice, and over time, the population became light colored. An explanation of how adaptations de- velop. Click image to the left or use the URL below. URL: "
"a mutation that is harmful, may become beneficial if",(A) The population changes (B) The environment changes (C) The genetic makeup of the population changes (D) None of these,B,"Many mutations have no effect on the proteins they encode. These mutations are considered neutral. Occasionally, a mutation may make a protein even better than it was before. Or the protein might help the organism adapt to a new environment. These mutations are considered beneficial. An example is a mutation that helps bacteria resist antibiotics. Bacteria with the mutation increase in numbers, so the mutation becomes more common. Other mutations are harmful. They may even be deadly. Harmful mutations often result in a protein that no longer can do its job. Some harmful mutations cause cancer or other genetic disorders. Mutations also vary in their effects depending on whether they occur in gametes or in other cells of the body. Mutations that occur in gametes can be passed on to offspring. An offspring that inherits a mutation in a gamete will have the mutation in all of its cells. Mutations that occur in body cells cannot be passed on to offspring. They are confined to just one cell and its daughter cells. These mutations may have little effect on an organism. "
"in nebraska, natural selection favors deer mice that",(A) Contrast with the color of the soil where they live (B) Are able to see over short grass (C) Match the color of the soil where they live (D) None of these,C,"The mechanism for evolution is natural selection. Traits become more or less common in a population depending on whether they are beneficial or harmful. An example of evolution by natural selection can be found in the deer mouse, species Peromyscus maniculatus. In Nebraska this mouse is typically brown, but after glaciers carried lighter sand over the darker soil in the Sand Hills, predators could more easily spot the dark mice. Natural selection favored the light mice, and over time, the population became light colored. An explanation of how adaptations de- velop. Click image to the left or use the URL below. URL: "
an organism is most likely to evolve if its,(A) Environment is changing (B) Environment is stable (C) Ancestors experienced a lot of mutations (D) Current individuals experience a lot of mutations,A,"Darwins theory of evolution has been under attack ever since Darwin proposed it. But nearly all biologists accept the theory and recognize that everything they learn about life on Earth supports the theory. Evolution is seen in the fossil record, in the developmental paths of organisms, in the geographic distribution of organisms, and in the genetic codes of living organisms. Evolution has a mechanism, called natural selection. People often refer to natural selection as the survival of the fittest. With natural selection, the organism that is best adapted to its environment will be most likely to survive and produce offspring, thus spreading its genes to the next generation. The theory of evolution maintains that modern humans evolved from ape-like ancestors. "
all the genetic variation that a population will have exists within it.,(A) True (B) False,B,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
changes in the genetic makeup of a population may result in,(A) A new species (B) A beneficial adaptation (C) A new variety or subspecies (D) All of the above,D,"Many changes in the genetic makeup of a species may accumulate over time, especially if the environment is changing. Eventually the descendants will be very different from their ancestors and may become a whole new species. Changes in the genetic makeup of a species over time are known as biological evolution. "
about how old is planet earth?,(A) 6 (B) 000 years (C) b 46 million years (D) c 46 billion years (E) d 60 billion years,C,"How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists, and naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: Fossils of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans. The many layers of rock. When people realized that rock layers represent the order in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth. Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earths surface. This supported the idea of an older Earth. The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years. "
how have scientists tried to calculate the age of earth?,(A) Measure how much sediment a stream deposited in a year and calculate how long it would take to deposit a sediment layer (B) Calculate how long it would take for the Earth to cool to its current temperature from a molten ball (C) Calculate the rate of evolution and determine how long it would take for modern animals to evolve (D) All of these,D,"During the 18th and 19th centuries, geologists tried to estimate the age of Earth with indirect techniques. What methods can you think of for doing this? One example is that by measuring how much sediment a stream deposited in a year, a geologist might try to determine how long it took for a stream to deposit an ancient sediment layer. Not surprisingly, these methods resulted in wildly different estimates. A relatively good estimate was produced by the British geologist Charles Lyell, who thought that 240 million years had passed since the appearance of the first animals with shells. Today scientists know that this event occurred about 530 million years ago. In 1892, William Thomson (later known as Lord Kelvin) calculated that the Earth was 100 million years old, which he later lowered to 20 million years. He did this systematically assuming that the planet started off as a molten ball and calculating the time it would take for it to cool to its current temperature. This estimate was a blow to geologists and supporters of Charles Darwins theory of evolution, which required an older Earth to provide time for geological and evolutionary processes to take place. Kelvins calculations were soon shown to be flawed when radioactivity was discovered in 1896. What Kelvin didnt know is that radioactive decay of elements inside Earths interior provides a steady source of heat. He also didnt know that the mantle is able to flow and so convection moves heat from the interior to the surface of the planet. Thomson had grossly underestimated Earths age. "
scientists can determine an exact number for the age of earth materials using radioactivity.,(A) True (B) False,A,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
this material is thought to have formed when the solar system was forming __________________.,(A) Earth’s oldest rocks (B) Meteorites (C) Earth’s atmosphere (D) All of the above,B,"The most widely accepted explanation of how the solar system formed is called the nebular hypothesis. According to this hypothesis, the Sun and the planets of our solar system formed about 4.6 billion years ago from the collapse of a giant cloud of gas and dust, called a nebula. The nebula was drawn together by gravity, which released gravitational potential energy. As small particles of dust and gas smashed together to create larger ones, they released kinetic energy. As the nebula collapsed, the gravity at the center increased and the cloud started to spin because of its angular momentum. As it collapsed further, the spinning got faster, much as an ice skater spins faster when he pulls his arms to his sides during a spin. Much of the clouds mass migrated to its center but the rest of the material flattened out in an enormous disk. The disk contained hydrogen and helium, along with heavier elements and even simple organic molecules. "
earths age is calculated using ages from,(A) Meteorites (B) Earth’s oldest rocks (C) Lunar rocks (D) All of the above,D,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
lord kelvin calculated earths age at 100 million years. what he didnt know was that,(A) Radioactive decay adds heat (B) The cooling rate of Earth materials is slower than he thought (C) Earth started out much hotter than he thought (D) All of these,A,"During the 18th and 19th centuries, geologists tried to estimate the age of Earth with indirect techniques. What methods can you think of for doing this? One example is that by measuring how much sediment a stream deposited in a year, a geologist might try to determine how long it took for a stream to deposit an ancient sediment layer. Not surprisingly, these methods resulted in wildly different estimates. A relatively good estimate was produced by the British geologist Charles Lyell, who thought that 240 million years had passed since the appearance of the first animals with shells. Today scientists know that this event occurred about 530 million years ago. In 1892, William Thomson (later known as Lord Kelvin) calculated that the Earth was 100 million years old, which he later lowered to 20 million years. He did this systematically assuming that the planet started off as a molten ball and calculating the time it would take for it to cool to its current temperature. This estimate was a blow to geologists and supporters of Charles Darwins theory of evolution, which required an older Earth to provide time for geological and evolutionary processes to take place. Kelvins calculations were soon shown to be flawed when radioactivity was discovered in 1896. What Kelvin didnt know is that radioactive decay of elements inside Earths interior provides a steady source of heat. He also didnt know that the mantle is able to flow and so convection moves heat from the interior to the surface of the planet. Thomson had grossly underestimated Earths age. "
geologists have pieced together earth history using all of the scientific tools available to them.,(A) True (B) False,A,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
earth had to be older than 100 million years because of,(A) The amount of time it takes one stream to deposit a sediment layer (B) The amount of time it would take for Earth to cool (C) The length of time it would take for organisms to evolve into modern animals (D) The amount of time that passed since the dinosaurs died out,C,"Early geologists had no way to determine the absolute age of a geological material. If they didnt see it form, they couldnt know if a rock was one hundred years or 100 million years old. What they could do was determine the ages of materials relative to each other. Using sensible principles they could say whether one rock was older than another and when a process occurred relative to those rocks. "
many lines of evidence indicate that earth is 4.6 billion years old.,(A) True (B) False,A,Earth formed 4.5 billion years ago. Geologists divide this time span into smaller periods. Many of the divisions mark major events in life history. 
"without radiometric dating, scientists would still know the absolute age of earth.",(A) True (B) False,B,"Radioactivity turned out to be useful for dating Earth materials and for coming up with a quantitative age for Earth. Scientists not only date ancient rocks from Earths crust, they also date meteorites that formed at the same time Earth and the rest of the solar system were forming. Moon rocks also have been radiometrically dated. Using a combination of radiometric dating, index fossils, and superposition, geologists have constructed a well- defined timeline of Earth history. With information gathered from all over the world, estimates of rock and fossil ages have become increasingly accurate. This is the modern geologic time scale with all of the ages. Click image to the left or use the URL below. URL: "
which of these statements is true?,(A) 10 (B) 000 years ago men hunted and fished (C) while women gathered nuts and vegetables (D) b Many anthropologists believe that the carrying capacity of humans without agriculture is about 10 million (E) c Advances in our brain capacity (F) erect posture and use of our hands helped advance the human population (G) d All of the above,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
farmers were able to increase the yield of food plants.,(A) True (B) False,A,"Every major advance in agriculture has allowed global population to increase. Early farmers could settle down to a steady food supply. Irrigation, the ability to clear large swaths of land for farming efficiently, and the development of farm machines powered by fossil fuels allowed people to grow more food and transport it to where it was needed. "
agriculture allowed people to,(A) Have food all year round (B) Settle down so that they no longer need to carry out all their possessions (C) Store food for when it is difficult to grow (D) All of the above,D,"About 10,000 years ago, we developed the ability to grow our own food. Farming increased the yield of food plants and allowed people to have food available year round. Animals were domesticated to provide meat. With agriculture, people could settle down, so that they no longer needed to carry all their possessions (Figure 1.2). They could develop better farming practices and store food for when it was difficult to grow. Agriculture allowed people to settle in towns and cities. More advanced farming practices allowed a single farmer to grow food for many more people. When advanced farming practices allowed farmers to grow more food than they needed for their families (Figure "
the industrial revolution was a major historical event that allowed ________________.,(A) People to live an agricultural lifestyle (B) Solar energy stored in fossil fuels to do the work that humans had done (C) People to make choices about population growth (D) All of the above,B,"The next major stage in the growth of the human population was the Industrial Revolution, which started in the late 1700s (Figure 1.4). This major historical event marks when products were first mass-produced and when fossil fuels were first widely used for power. "
one side benefit of the industrial revolution is that,(A) People were free to develop the arts and culture (B) People no longer have to be scared by dark skies at night (C) People were freed from boring dangerous labor (D) None of the above,A,"Few technologies have impacted society as greatly as the powerful steam engine developed by Scottish inventor James Watt in 1775 (see Figure 1.1). Watts steam engine was soon being used to power all kinds of machines. It started a revolution in industry. For the first time in history, people did not have to rely on human or animal muscle, wind, or water for power. With the steam engine to power machines, new factories sprang up all over Britain. The Industrial Revolution began in Britain the late 1700s. It eventually spread throughout Western Europe, North America, Japan, and many other countries. It marked a major turning point in human history. Almost every aspect of daily life was influenced by it in some way. Average income and population both began to grow faster than ever before. People flocked to the new factories for jobs, and densely populated towns and cities grew up around the factories. The new towns and cities were crowded, and soot from the factories polluted the air. You can see an example of this in the Figure 1.2. This made living conditions very poor. Working conditions in the factories were also bad, with long hours and the pace set by machines. Even young children worked in the factories, damaging their health and giving them little opportunity for education or play. Q: In addition to factory machines, the steam engine was used to power farm machinery, trains, and ships. What effects might this have had on peoples lives? A: Farm machinery replaced human labor and allowed fewer people to produce more food. This is why many rural people migrated to the new towns and cities to look for work in factories. Steam-powered trains and ships made it easier for people to migrate. Food and factory goods could also be transported on steam-powered trains and ships, making them available to far more people. "
the use of artificial fertilizers and chemical pesticides has not increased much in the past 50 years.,(A) True (B) False,B,"The Green Revolution has allowed the addition of billions of people to the population in the past few decades. The Green Revolution has improved agricultural productivity by: Improving crops by selecting for traits that promote productivity; recently, genetically engineered crops have been introduced. Increasing the use of artificial fertilizers and chemical pesticides. About 23 times more fertilizer and 50 times more pesticides are used around the world than were used just 50 years ago (Figure 1.5). Agricultural machinery: plowing, tilling, fertilizing, picking, and transporting are all done by machines. About 17% of the energy used each year in the United States is for agriculture. Increasing access to water. Many farming regions depend on groundwater, which is not a renewable resource. Some regions will eventually run out of this water source. Currently about 70% of the worlds fresh water is used for agriculture. Rows of a single crop and heavy ma- chinery are normal sights for modern day farms. The Green Revolution has increased the productivity of farms immensely. A century ago, a single farmer produced enough food for 2.5 people, but now a farmer can feed more than 130 people. The Green Revolution is credited for feeding 1 billion people that would not otherwise have been able to live. "
this scientist in the eighteenth century predicted that human population would continue to grow until we had exhausted our resources.,(A) Thomas Malthus (B) Thomas Edison (C) Alfred Wegener (D) Louis Leakey,A,"The flip side to this is that for the population to continue to grow, more advances in agriculture and an ever increasing supply of water will be needed. Weve increased the carrying capacity for humans by our genius: growing crops, trading for needed materials, and designing ways to exploit resources that are difficult to get at, such as groundwater. And most of these resources are limited. The question is, even though we have increased the carrying capacity of the planet, have we now exceeded it (Figure There is not yet an answer to that question, but there are many different opinions. In the eighteenth century, Thomas Malthus predicted that human population would continue to grow until we had exhausted our resources. At that point, humans would become victims of famine, disease, or war. This has not happened, at least not yet. Some scientists think that the carrying capacity of the planet is about 1 billion people, not the 7 billion people we have today. The limiting factors have changed as our intelligence has allowed us to expand our population. Can we continue to do this indefinitely into the future? "
the green revolution has,(A) Greatly increased agricultural productivity (B) Allowed the human population to increase by billions more than it would have (C) Use groundwater and fossil fuels in ways that are unsustainable (D) All of the above,D,The Green Revolution has brought enormous impacts to the planet. 
it is possible that earths carrying capacity for humans is around 1 billion.,(A) True (B) False,A,"What is Earths carrying capacity for humans? Are humans now exceeding Earths carrying capacity for our species? Many anthropologists say that the carrying capacity of humans on the planet without agriculture is about 10 million (Figure 1.1). This population was reached about 10,000 years ago. At the time, people lived together in small bands of hunters and gatherers. Typically men hunted and fished; women gathered nuts and vegetables. Obviously, human populations have blown past this hypothetical carrying capacity. By using our brains, our erect posture, and our hands, we have been able to manipulate our environment in ways that no other species has ever done. What have been the important developments that have allowed population to grow? "
human population is currently,(A) Held down by limiting factors (B) Well with the limits of the population that Earth can support (C) Very likely exceeding Earth’s carrying capacity for humans (D) All of the above,C,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
all air pollutants are human-made materials.,(A) True (B) False,B,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
air pollution became more widespread as fossil fuels began to be burned for energy during the,(A) American Revolution (B) Green Revolution (C) Industrial Revolution (D) Russian Revolution,C,Air pollution started to be a problem when early people burned wood for heat and cooking fires in enclosed spaces such as caves and small tents or houses. But the problems became more widespread as fossil fuels such as coal began to be burned during the Industrial Revolution (Figure 1.1). The 2012 Olympic Games in London opening ceremony contained a reen- actment of the Industrial Revolution - complete with pollution streaming from smokestacks. 
air pollution is,(A) Released directly into the air (B) The result of chemical reactions (C) Still occurring despite the implementation of the Clean Air Act (D) All of these,D,"Outdoor air pollution causes serious human health problems. For example, pollutants in the air are major contributors to respiratory and cardiovascular diseases. Air pollution may trigger asthma attacks and heart attacks in people with underlying health problems. In fact, more people die each year from air pollution than automobile accidents. "
photochemical smog is common in southern california because of,(A) The abundance of cars and sunshine (B) The high number of industries (C) The intensive agriculture (D) The dust that blows off the deserts in the east,A,"Photochemical smog, a different type of air pollution, first became a problem in Southern California after World War II. The abundance of cars and sunshine provided the perfect setting for a chemical reaction between some of the molecules in auto exhaust or oil refinery emissions and sunshine (Figure 1.2). Photochemical smog consists of more than 100 compounds, most importantly ozone. Smog over Los Angeles as viewed from the Hollywood Hills. "
"as of 2013, the clean air act regulates this many pollutants.",(A) 89 (B) 189 (C) 289 (D) 389,A,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
"as of 2013, most of the smoggiest cities in the united states were in california.",(A) True (B) False,A,"Air quality in a region is not just affected by the amount of pollutants released into the atmosphere in that location but by other geographical and atmospheric factors. Winds can move pollutants into or out of a region and a mountain range can trap pollutants on its leeward side. Inversions commonly trap pollutants within a cool air mass. If the inversion lasts long enough, pollution can reach dangerous levels. Pollutants remain over a region until they are transported out of the area by wind, diluted by air blown in from another region, transformed into other compounds, or carried to the ground when mixed with rain or snow. Table 1.1 lists the smoggiest cities in 2013: 7 of the 10 are in California. Why do you think California cities are among those with the worst air pollution? The state has the right conditions for collecting pollutants including mountain ranges that trap smoggy air, arid and sometimes windless conditions, agriculture, industry, and lots and lots of cars. Rank 1 2 3 4 5 6 7 8 9 10 City, State Los Angeles area, California Visalia-Porterville, California Bakersfield-Delano, California Fresno-Madera, California Hanford-Corcoran, California Sacramento area, California Houston area, Texas Dallas-Fort Worth, Texas Washington D.C. area El Centro, California "
passage of the clean air act of 1970 was a response to,(A) Air pollution events in which many people died (B) Awareness of the dangers of photochemical smog (C) Recognition that excess carbon dioxide was raising global temperatures (D) A & B,D,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
the six important pollutants that were regulated in the clean air act of 1970 are,(A) Carbon dioxide (B) methane (C) carbon monoxide (D) CFCs (E) water vapor and nitrous oxide (F) b Benzene (G) perchloroethylene (H) methylene chloride (I) dioxin (J) and asbestos (K) c Ozone (L) particulates (M) sulfur dioxide (N) nitrogen dioxide (O) carbon monoxide and lead (P) d Cadmium (Q) mercury (R) lead (S) chromium (T) sulfur and silver compounds,C,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
parts of california are especially susceptible to trapping smog due to its,(A) Abundant mountain ranges (B) Inversions (C) Dry and wind-free conditions (D) All of these,D,"Air quality in a region is not just affected by the amount of pollutants released into the atmosphere in that location but by other geographical and atmospheric factors. Winds can move pollutants into or out of a region and a mountain range can trap pollutants on its leeward side. Inversions commonly trap pollutants within a cool air mass. If the inversion lasts long enough, pollution can reach dangerous levels. Pollutants remain over a region until they are transported out of the area by wind, diluted by air blown in from another region, transformed into other compounds, or carried to the ground when mixed with rain or snow. Table 1.1 lists the smoggiest cities in 2013: 7 of the 10 are in California. Why do you think California cities are among those with the worst air pollution? The state has the right conditions for collecting pollutants including mountain ranges that trap smoggy air, arid and sometimes windless conditions, agriculture, industry, and lots and lots of cars. Rank 1 2 3 4 5 6 7 8 9 10 City, State Los Angeles area, California Visalia-Porterville, California Bakersfield-Delano, California Fresno-Madera, California Hanford-Corcoran, California Sacramento area, California Houston area, Texas Dallas-Fort Worth, Texas Washington D.C. area El Centro, California "
smog can build up on a winter day because inversions trap pollutants in a cool air mass.,(A) True (B) False,A,"Sometimes air doesnt mix in the troposphere. This happens when air is cooler close to the ground than it is above. The cool air is dense, so it stays near the ground. This is called a temperature inversion. An inversion can trap air pollution near the surface. Temperature inversions are more common in the winter. Can you explain why? "
an asteroid is,(A) A rock and ice body that has a tail near the Sun (B) A rounded body with craters on it (C) A small rocky body that orbits the Sun (D) None of the above,C,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
asteroids,(A) Came together to form the rocky planets (B) Came together to form the Moon (C) Hardly ever venture into the inner solar system (D) All of these,A,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
asteroids are too small to have impacts with other objects so they dont have craters.,(A) True (B) False,B,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
we dont know much about asteroids because they are too small for nasa missions to visit them.,(A) True (B) False,B,"Scientists are very interested in asteroids. Most are composed of material that has not changed since early in the solar system. Scientists can learn a lot from them about how the solar system formed. Asteroids may be important for space travel. They could be mined for rare minerals or for construction projects in space. Scientists have sent spacecraft to study asteroids. In 1997, the NEAR Shoemaker probe orbited the asteroid 433 Eros. The craft finally landed on its surface in 2001. The Japanese Hayabusa probe returned to Earth with samples of a small near-earth asteroid in 2010. The U.S. Dawn mission will visit Vesta in 2011 and Ceres in 2015. "
asteroids,(A) Are mostly found between the orbits of Jupiter and Saturn (B) Are still being discovered at a high rate (C) Could be added up to equal the mass of a Mars-sized planet (D) All of these,B,"Asteroids are very small, rocky bodies that orbit the Sun. ""Asteroid"" means ""star-like,"" and in a telescope, asteroids look like points of light, just like stars. Asteroids are irregularly shaped because they do not have enough gravity to become round. They are also too small to maintain an atmosphere, and without internal heat they are not geologically active (Figure 1.1). Collisions with other bodies may break up the asteroid or create craters on its surface. Asteroid impacts have had dramatic impacts on the shaping of the planets, including Earth. Early impacts caused the planets to grow as they cleared their portions of space. An impact with an asteroid about the size of Mars caused fragments of Earth to fly into space and ultimately create the Moon. Asteroid impacts are linked to mass extinctions throughout Earths history. "
the region where asteroids orbit between mars and jupiter is called _________.,(A) The cometary zone (B) The near-Earth asteroid zone (C) The Kuiper Belt (D) The asteroid belt,D,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
near-earth asteroids can,(A) Cross Earth’s orbit (B) Cause mass extinctions (C) Be over 1 km in diameter (D) All of the above,D,"Near-Earth asteroids have orbits that cross Earths orbit. This means that they can collide with Earth. There are over 4,500 known near-Earth asteroids. Small asteroids do sometimes collide with Earth. An asteroid about 510 m in diameter hits about once per year. Five hundred to a thousand of the known near-Earth asteroids are much bigger. They are over 1 kilometer in diameter. When large asteroids hit Earth in the past, many organisms died. At times, many species became extinct. Astronomers keep looking for near-Earth asteroids. They hope to predict a possible collision early so they can to try to stop it. "
an asteroid the size of mars hit earth sending fragments of earth into space to create the moon.,(A) True (B) False,A,"This model for how the Moon formed is the best fit of all of the data scientists have about the Moon. In the early solar system there was a lot of space debris. Asteroids flew around, sometimes striking the planets. An asteroid the size of Mars smashed into Earth. The huge amount of energy from the impact melted most of Earth. The asteroid melted too. Material from both Earth and the asteroid was thrown out into orbit. Over time, this material smashed together to form our Moon. The lunar surface is about 4.5 billion years old. This means that the collision happened about 70 million years after Earth formed. "
an asteroid could cause humans to go extinct.,(A) True (B) False,A,"Near-Earth asteroids have orbits that cross Earths orbit. This means that they can collide with Earth. There are over 4,500 known near-Earth asteroids. Small asteroids do sometimes collide with Earth. An asteroid about 510 m in diameter hits about once per year. Five hundred to a thousand of the known near-Earth asteroids are much bigger. They are over 1 kilometer in diameter. When large asteroids hit Earth in the past, many organisms died. At times, many species became extinct. Astronomers keep looking for near-Earth asteroids. They hope to predict a possible collision early so they can to try to stop it. "
scientists are interested in asteroids because many,(A) Contain very valuable gemstones (B) Contain precious metals (C) Are representatives of the earliest solar system (D) Could have primitive life forms,C,Scientists are interested in asteroids because they are representatives of the earliest solar system (Figure 1.4). Eventually asteroids could be mined for rare minerals or for construction projects in space. A few missions have studied asteroids directly. NASAs DAWN mission explored asteroid Vesta in 2011 and 2012 and will visit dwarf planet Ceres in 2015. Click image to the left or use the URL below. URL:  The NEAR Shoemaker probe took this photo as it was about to land on 433 Eros in 2001. 
which factor affects resource availability?,(A) Supply (B) Price (C) Politics (D) All of the above,D,"Besides abundance, a resources value is determined by how easy it is to locate and extract. If a resource is difficult to use, it will not be used until the price for that resource becomes so great that it is worth paying for. For example, the oceans are filled with an abundant supply of water, but desalination is costly, so it is used only where water is really limited (Figure 1.1). As the cost of desalination plants comes down, more will likely be built. Tampa Bay, Florida, has one of the few desalination plants in the United States. "
"if a nation is wealthy, it can determine the price of a resource.",(A) True (B) False,B,"Besides abundance, a resources value is determined by how easy it is to locate and extract. If a resource is difficult to use, it will not be used until the price for that resource becomes so great that it is worth paying for. For example, the oceans are filled with an abundant supply of water, but desalination is costly, so it is used only where water is really limited (Figure 1.1). As the cost of desalination plants comes down, more will likely be built. Tampa Bay, Florida, has one of the few desalination plants in the United States. "
nonrenewable resources,(A) Are usually quite limited in abundance (B) Are extremely valuable (C) May be extremely abundant (D) Are rarely very valuable,C,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
overconsumption is the recognition that people in developed countries use many more natural resources than people in developing countries.,(A) True (B) False,A,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
discarding an item costs natural resources and contributes to pollution.,(A) True (B) False,A,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
another word for electronic waste is ___________.,(A) E-waste (B) E-cycle (C) Electro-garbage (D) Electro-trash,A,"Many of the devices people commonly use today are electronic devices. Electronic devices use electric current to encode, analyze, or transmit information. In addition to computers, they include mobile phones, TV remotes, DVD and CD players, and digital cameras, to name just a few. Q: Can you think of other electronic devices that you use? A: Other examples include game systems and MP3 players. "
a nation with a lot of neodymium may __________ that resource to other countries that will __________ it.,(A) Export; export (B) Export; import (C) Import; export (D) Import; import,B,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
electronic waste generated in developed nations,(A) Is disposed of safely (B) Is not valuable to anyone (C) Exposes people in developing nations to hazardous compounds (D) None of these,C,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
"since natural resources are distributed fairly evenly around the planet, nations can usually obtain what they need.",(A) True (B) False,B,"Rich nations use more natural resources than poor nations. In fact, the richest 20 percent of people use 85 percent of the worlds resources. What about the poorest 20 percent of people? They use only 1 percent of the worlds resources. You can see this unequal distribution of oil resources in Figure 20.3. Imagine a world in which everybody had equal access to resources. Some people would have fewer resources than they do now. But many people would have more. In the real world, the difference between rich and poor just keeps growing. "
"if a resource becomes scarce, the result may be",(A) A rise in price of that resource (B) Interest in finding more of that resource (C) War (D) All of these,D,"Besides abundance, a resources value is determined by how easy it is to locate and extract. If a resource is difficult to use, it will not be used until the price for that resource becomes so great that it is worth paying for. For example, the oceans are filled with an abundant supply of water, but desalination is costly, so it is used only where water is really limited (Figure 1.1). As the cost of desalination plants comes down, more will likely be built. Tampa Bay, Florida, has one of the few desalination plants in the United States. "
very flat areas that make up much of the ocean floor are,(A) Plateaus (B) Trenches (C) Abyssal Plains (D) Mid-ocean ridges,C,"Scientists have learned a lot about the ocean floor. For example, they know that Earths tallest mountains and deepest canyons are on the ocean floor. The major features on the ocean floor are described below. They are also shown in Figure 14.22. The continental shelf is the ocean floor nearest the edges of continents. It has a a gentle slope. The water over the continental shelf is shallow. The continental slope lies between the continental shelf and the abyssal plain. It has a steep slope with a sharp drop to the deep ocean floor. The abyssal plain forms much of the floor under the open ocean. It lies from 3 to 6 kilometers (1.9 to 3.7 miles) below the surface. Much of it is flat. An oceanic trench is a deep canyon on the ocean floor. Trenches occur where one tectonic plate subducts under another. The deepest trench is the Mariana Trench in the Pacific Ocean. It plunges more than 11 kilometers (almost 7 miles) below sea level. A seamount is a volcanic mountain on the ocean floor. Seamounts that rise above the water surface are known as islands. There are many seamounts dotting the seafloor. The mid-ocean ridge is a mountain range that runs through all the worlds oceans. It is almost 64,000 kilometers (40,000 miles) long! It forms where tectonic plates pull apart. Magma erupts through the ocean floor to make new seafloor. The magma hardens to create the ridge. "
on a bathymetric map where shallower depths are lighter blue and deeper depths are darker blue,(A) The light blue gashes are mid-ocean ridges and the dark thin lines are the trenches (B) The mid-ocean ridges are dark blue lines and the trenches are light blue arcs (C) The entire ocean floor appears as a deep blue (D) The deepest depths are along the mid-ocean ridges and the shallowest depths are along the abyssal plains,A,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
longest chain of mountains in the world.,(A) Abyssal plains (B) Trenches (C) Continental margins (D) Mid-ocean ridges,D,Continent-continent convergence creates some of the worlds largest mountains ranges. The Himalayas (Figure are the remnants of a larger mountain range. This range formed from continent-continent collisions in the time of Pangaea. 
"to map seafloor bathymetry, a research vessel uses an echo sounder, which",(A) Uses a sound beam to determine the depth to the seafloor (B) Takes photos of the seafloor and then creates a map from them (C) Carries a crew of three scientists and pilots to map the seafloor (D) Is dropped to the seafloor on a line with the length of the line that is submerged indicating seafloor depth in that area,A,"The people who first mapped the seafloor were aboard military vessels during World War II. As stated in the Earth as a Planet chapter, echo sounders used sound waves to search for submarines, but also produced a map of seafloor depths. Depth sounding continued in earnest after the war. Scientists pieced together the ocean depths to produce bathymetric maps of the seafloor. During WWII and in the decade or so later, echo sounders had only one beam, so they just returned a line showing the depth beneath the ship. Later echo sounders sent out multiple beams and could create a bathymetric map of the seafloor below. We will run a multi-beam echo sounder as we go from Woods Hole out to the Mid-Atlantic Ridge. "
the study of underwater depth of lake or ocean floor.,(A) Geomorphology (B) Climatology (C) Bathymetry (D) Glaciology,C,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
"from the bottom of the deepest trench to the top of the highest mountain, the relief of the pacific ocean basin totals nearly 70,000 feet.",(A) True (B) False,A,"As we have seen, the ocean floor is not flat: mid-ocean ridges, deep sea trenches, and other features all rise sharply above or plunge deeply below the abyssal plains. In fact, Earths tallest mountain is Mauna Kea volcano, which rises 10,203 m (33,476 ft.)meters) from the Pacific Ocean floor to become one of the volcanic mountains of Hawaii. The deepest canyon is also on the ocean floor, the Challenger Deep in the Marianas Trench, 10,916 m (35,814 ft). The continental margin is the transition from the land to the deep sea or, geologically speaking, from continental crust to oceanic crust. More than one-quarter of the ocean basin is continental margin. (Figure 1.3). Click image to the left or use the URL below. URL: "
this is the transition from the land to the deep sea.,(A) Continental Drift (B) Continental Shelf (C) Continental Rise (D) Continental Margin,D,The Paleozoic saw the evolution a tremendous diversity of life throughout the seas and onto land. 
earths tallest mountain from base to top is,(A) Everest (B) Mauna Kea (C) Chimborazo (D) McKinley,B,"As we have seen, the ocean floor is not flat: mid-ocean ridges, deep sea trenches, and other features all rise sharply above or plunge deeply below the abyssal plains. In fact, Earths tallest mountain is Mauna Kea volcano, which rises 10,203 m (33,476 ft.)meters) from the Pacific Ocean floor to become one of the volcanic mountains of Hawaii. The deepest canyon is also on the ocean floor, the Challenger Deep in the Marianas Trench, 10,916 m (35,814 ft). The continental margin is the transition from the land to the deep sea or, geologically speaking, from continental crust to oceanic crust. More than one-quarter of the ocean basin is continental margin. (Figure 1.3). Click image to the left or use the URL below. URL: "
"the continental shelf is made up of the continental margin, continental slope and continental rise.",(A) True (B) False,B,"The ocean basin begins where the ocean meets the land. The continental margin begins at the shore and goes down to the ocean floor. It includes the continental shelf, slope, and rise. The continental shelf is part of the continent, but it is underwater today. It is about 100-200 meters deep, much shallower than the rest of the ocean. The continental shelf usually goes out about 100 to 200 kilometers from the shore (Figure 2.9). The continental slope is the slope that forms the edge of the continent. It is seaward of the continental shelf. In some places, a large pile of sediments brought from rivers creates the continental rise. The continental rise ends at the Besides seamounts, there are long, very tall (about 2 km) mountain ranges. These ranges are connected so that they form huge ridge systems called mid-ocean ridges (Figure 2.11). The mid-ocean ridges form from volcanic eruptions. Lava from inside Earth breaks through the crust and creates the mountains. The deepest places of the ocean are the ocean trenches. Many trenches line the edges of the Pacific Ocean. The Mariana Trench is the deepest place in the ocean. (Figure 2.12). At about 11 km deep, it is the deepest place on Earth! To compare, the tallest place on Earth, Mount Everest, is less than 9 km tall. "
the deepest canyon in the ocean floor.,(A) Hellenic Trench (B) Philippine Trench (C) Marianas Trench (D) Japan Trench,C,"As we have seen, the ocean floor is not flat: mid-ocean ridges, deep sea trenches, and other features all rise sharply above or plunge deeply below the abyssal plains. In fact, Earths tallest mountain is Mauna Kea volcano, which rises 10,203 m (33,476 ft.)meters) from the Pacific Ocean floor to become one of the volcanic mountains of Hawaii. The deepest canyon is also on the ocean floor, the Challenger Deep in the Marianas Trench, 10,916 m (35,814 ft). The continental margin is the transition from the land to the deep sea or, geologically speaking, from continental crust to oceanic crust. More than one-quarter of the ocean basin is continental margin. (Figure 1.3). Click image to the left or use the URL below. URL: "
the big bang theory is a hypothesis that states that all matter and energy were at one time compressed into a small volume and then ____________.,(A) Imploded (B) Expanded outward (C) Stayed compressed (D) None of the above,B,"About 13.7 billion years ago, the entire universe was packed together. Everything was squeezed into a tiny volume. Then there was an enormous explosion. After this big bang, the universe expanded rapidly (Figure 26.16). All of the matter and energy in the universe has been expanding ever since. Scientists have evidence this is how the universe formed. One piece of evidence is that we see galaxies moving away from us. If they are moving apart, they must once have been together. Also, there is energy left over from this explosion throughout the universe. The theory for the origin of the universe is called the Big Bang Theory. "
the first stars didnt form until about 4 billion years after the big bang.,(A) True (B) False,B,"In the first few moments after the Big Bang, the universe was unimaginably hot and dense. As the universe expanded, it became less dense and began to cool. After only a few seconds, protons, neutrons, and electrons could form. After a few minutes, those subatomic particles came together to create hydrogen. Energy in the universe was great enough to initiate nuclear fusion, and hydrogen nuclei were fused into helium nuclei. The first neutral atoms that included electrons did not form until about 380,000 years later. The matter in the early universe was not smoothly distributed across space. Dense clumps of matter held close together by gravity were spread around. Eventually, these clumps formed countless trillions of stars, billions of galaxies, and other structures that now form most of the visible mass of the universe. If you look at an image of galaxies at the far edge of what we can see, you are looking at great distances. But you are also looking across a different type of distance. What do those far away galaxies represent? Because it takes so long for light from so far away to reach us, you are also looking back in time (Figure 1.2). "
"according to the big bang theory, the universe began",(A) 1 billion years ago (B) 37 billion years ago (C) 137 billion years ago (D) 237 billion years ago,C,"The Big Bang Theory is the dominant and highly supported theory of the origin of the universe. It states that the universe began from an initial point which has expanded over billions of years to form the universe as we now know it. In 1922, Alexander Friedman found that the solutions to Einsteins general relativity equations resulted in an expanding universe. Einstein, at that time, believed in a static, eternal universe so he added a constant to his equations to eliminate the expansion. Einstein would later call this the biggest blunder of his life. In 1924, Edwin Hubble was able to measure the distance to observed celestial objects that were thought to be nebula and discovered that they were so far away they were not actually part of the Milky Way (the galaxy containing our sun). He discovered that the Milky Way was only one of many galaxies. In 1927, Georges Lemaitre, a physicist, suggested that the universe must be expanding. Lemaitres theory was supported by Hubble in 1929 when he found that the galaxies most distant from us also had the greatest red shift (were moving away from us with the greatest speed). The idea that the most distance galaxies were moving away from us at the greatest speed was exactly what was predicted by Lemaitre. In 1931, Lemaitre went further with his predictions and by extrapolating backwards, found that the matter of the universe would reach an infinite density and temperature at a finite time in the past (around 15 billion years). This meant that the universe must have begun as a small, extremely dense point of matter. At the time, the only other theory that competed with Lemaitres theory was the Steady State Theory of Fred Hoyle. The steady state theory predicted that new matter was created which made it appear that the universe was expanding but that the universe was constant. It was Hoyle who coined the term Big Bang Theory which he used as a derisive name for Lemaitres theory. George Gamow (1904 - 1968) was the major advocate of the Big Bang theory. He predicted that cosmic microwave background radiation should exist throughout the universe as a remnant of the Big Bang. As atoms formed from sub-atomic particles shortly after the Big Bang, electromagnetic radiation would be emitted and this radiation would still be observable today. Gamow predicted that the expansion of the universe would cool the original radiation so that now the radiation would be in the microwave range. The debate continued until 1965 when two Bell Telephone scientists stumbled upon the microwave radiation with their radio telescope. "
at the time of the big bang and just after,(A) All the matter and energy of the universe was compressed into a point (B) After a few seconds (C) protons (D) neutrons and electrons formed (E) c After a few minutes (F) hydrogen formed (G) d All of the above,D,"The Big Bang Theory is the dominant and highly supported theory of the origin of the universe. It states that the universe began from an initial point which has expanded over billions of years to form the universe as we now know it. In 1922, Alexander Friedman found that the solutions to Einsteins general relativity equations resulted in an expanding universe. Einstein, at that time, believed in a static, eternal universe so he added a constant to his equations to eliminate the expansion. Einstein would later call this the biggest blunder of his life. In 1924, Edwin Hubble was able to measure the distance to observed celestial objects that were thought to be nebula and discovered that they were so far away they were not actually part of the Milky Way (the galaxy containing our sun). He discovered that the Milky Way was only one of many galaxies. In 1927, Georges Lemaitre, a physicist, suggested that the universe must be expanding. Lemaitres theory was supported by Hubble in 1929 when he found that the galaxies most distant from us also had the greatest red shift (were moving away from us with the greatest speed). The idea that the most distance galaxies were moving away from us at the greatest speed was exactly what was predicted by Lemaitre. In 1931, Lemaitre went further with his predictions and by extrapolating backwards, found that the matter of the universe would reach an infinite density and temperature at a finite time in the past (around 15 billion years). This meant that the universe must have begun as a small, extremely dense point of matter. At the time, the only other theory that competed with Lemaitres theory was the Steady State Theory of Fred Hoyle. The steady state theory predicted that new matter was created which made it appear that the universe was expanding but that the universe was constant. It was Hoyle who coined the term Big Bang Theory which he used as a derisive name for Lemaitres theory. George Gamow (1904 - 1968) was the major advocate of the Big Bang theory. He predicted that cosmic microwave background radiation should exist throughout the universe as a remnant of the Big Bang. As atoms formed from sub-atomic particles shortly after the Big Bang, electromagnetic radiation would be emitted and this radiation would still be observable today. Gamow predicted that the expansion of the universe would cool the original radiation so that now the radiation would be in the microwave range. The debate continued until 1965 when two Bell Telephone scientists stumbled upon the microwave radiation with their radio telescope. "
"during the immediate aftermath of the big bang, hydrogen nuclei collided and fused into __________ nuclei.",(A) Oxygen (B) Carbon (C) Helium (D) Potassium,C,"In the first few moments after the Big Bang, the universe was extremely hot and dense. As the universe expanded, it became less dense. It began to cool. First protons, neutrons, and electrons formed. From these particles came hydrogen. Nuclear fusion created helium atoms. Some parts of the universe had matter that was densely packed. Enormous clumps of matter were held together by gravity. Eventually this material became the gas clouds, stars, galaxies, and other structures that we see in the universe today. "
"in the early universe, matter was held together by which force?",(A) Gravity (B) Centrifugal (C) Inertia (D) Attractive,A,"In the first few moments after the Big Bang, the universe was extremely hot and dense. As the universe expanded, it became less dense. It began to cool. First protons, neutrons, and electrons formed. From these particles came hydrogen. Nuclear fusion created helium atoms. Some parts of the universe had matter that was densely packed. Enormous clumps of matter were held together by gravity. Eventually this material became the gas clouds, stars, galaxies, and other structures that we see in the universe today. "
scientists have discovered the temperature of space is 3oc.,(A) True (B) False,B,"After the origin of the Big Bang hypothesis, many astronomers still thought the universe was static. Nearly all came around when an important line of evidence for the Big Bang was discovered in 1964. In a static universe, the space between objects should have no heat at all; the temperature should measure 0 K (Kelvin is an absolute temperature scale). But two researchers at Bell Laboratories used a microwave receiver to learn that the background radiation in the universe is not 0 K, but 3 K (Figure 1.3). This tiny amount of heat is left over from the Big Bang. Since nearly Images from very far away show what the universe was like not too long after the Big Bang. all astronomers now accept the Big Bang hypothesis, what is it usually referred to as? Click image to the left or use the URL below. URL: "
which of the following is true?,(A) The temperature of space in the universe is 0 Kelvin (B) A tiny amount of heat left over from the Big Bang is spread around the universe (C) Galaxies and the space between them are the same temperature (D) There is no evidence for the Big Bang beyond the expanding universe,B,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
"at the farthest edges of what scientists can see, there are",(A) Galaxies that formed not long after the Big Bang (B) Galaxies that formed recently (C) No things that astronomers can identify (D) Nothing but blobs of gas and dust,A,"What did the ancient Greeks recognize as the universe? In their model, the universe contained Earth at the center, the Sun, the Moon, five planets, and a sphere to which all the stars were attached. This idea held for many centuries until Galileos telescope helped people recognize that Earth is not the center of the universe. They also found out that there are many more stars than were visible to the naked eye. All of those stars were in the Milky Way Galaxy. In the early 20th century, an astronomer named Edwin Hubble (Figure 1.1) discovered that what scientists called the Andromeda Nebula was actually over 2 million light years away  many times farther than the farthest distances that had ever been measured. Hubble realized that many of the objects that astronomers called nebulas were not actually clouds of gas, but were collections of millions or billions of stars  what we now call galaxies. Hubble showed that the universe was much larger than our own galaxy. Today, we know that the universe contains about a hundred billion galaxies  about the same number of galaxies as there are stars in the Milky Way Galaxy. (a) Edwin Hubble used the 100-inch reflecting telescope at the Mount Wilson Observatory in California to show that some distant specks of light were galaxies. (b) Hubbles namesake space telescope spotted this six galaxy group. Edwin Hubble demonstrated the existence of galaxies. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
its very difficult to determine scientifically what existed before the big bang because there is no evidence.,(A) True (B) False,A,"After the origin of the Big Bang hypothesis, many astronomers still thought the universe was static. Nearly all came around when an important line of evidence for the Big Bang was discovered in 1964. In a static universe, the space between objects should have no heat at all; the temperature should measure 0 K (Kelvin is an absolute temperature scale). But two researchers at Bell Laboratories used a microwave receiver to learn that the background radiation in the universe is not 0 K, but 3 K (Figure 1.3). This tiny amount of heat is left over from the Big Bang. Since nearly Images from very far away show what the universe was like not too long after the Big Bang. all astronomers now accept the Big Bang hypothesis, what is it usually referred to as? Click image to the left or use the URL below. URL: "
which statement is not true about carbon?,(A) It is the most common element in the human body (B) Diamonds are made of carbon (C) It is part of CO2 (D) Fats contain carbon,A,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
you breathe in oxygen and breathe out carbon dioxide.,(A) True (B) False,A,"The process of getting oxygen into the body and releasing carbon dioxide is called respiration. Sometimes breathing is called respiration, but there is much more to respiration than just breathing. Breathing is only the movement of oxygen into the body and carbon dioxide out of the body. The process of respiration also includes the exchange of oxygen and carbon dioxide between the blood and the cells of the body. "
the waste product of photosynthesis is,(A) Glucose (B) Carbon dioxide (C) Oxygen (D) All of the above,C,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
respiration and photosynthesis are gas exchange processes with the exchange being between co2 and o2.,(A) True (B) False,A,"The bodys exchange of oxygen and carbon dioxide with the air is called respiration. Respiration actually consists of two stages. In one stage, air is taken into the body and carbon dioxide is released to the outside air. In the other stage, oxygen is delivered to all the cells of the body and carbon dioxide is carried away from the cells. Another kind of respiration takes place within body cells. This kind of respiration is called cellular respiration. Its the process in which cells obtain energy by burning glucose. Both types of respiration are connected. Cellular respiration uses oxygen and produces carbon dioxide. Respiration by the respiratory system supplies the oxygen needed for cellular respiration. It also removes the carbon dioxide produced by cellular respiration. "
"in photosynthesis, plants change this into chemical energy that plants and animals can use as food.",(A) Sunlight (B) Oxygen (C) Sugar (D) All of the above,A,Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy ! C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose is used for energy by the cells of almost all living things. Plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). How do living things get energy from glucose? The answer is cellular respiration. 
this is an example of a carbon source.,(A) Forest (B) Ocean (C) Fault (D) Volcano,D,"Places in the ecosystem that store carbon are reservoirs. Places that supply and remove carbon are carbon sources and carbon sinks, respectively. If more carbon is provided than stored, the place is a carbon source. If more carbon dioxide is absorbed than is emitted, the reservoir is a carbon sink. What are some examples of carbon sources and sinks? Carbon sinks are reservoirs where carbon is stored. Healthy living forests and the oceans act as carbon sinks. Carbon sources are reservoirs from which carbon can enter the environment. The mantle is a source of carbon from volcanic gases. A reservoir can change from a sink to a source and vice versa. A forest is a sink, but when the forest burns it becomes a source. The amount of time that carbon stays, on average, in a reservoir is the residence time of carbon in that reservoir. "
"the amount of carbon dioxide in the atmosphere is very low, but small changes make a big difference.",(A) True (B) False,A,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
"some things are sinks for co2 until they are burned or warmed and then they become sources, including:",(A) Forests (B) Fossil fuels (C) Oceans (D) All of these,D,"Humans have changed the natural balance of the carbon cycle because we use coal, oil, and natural gas to supply our energy demands. Fossil fuels are a sink for CO2 when they form, but they are a source for CO2 when they are burned. The equation for combustion of propane, which is a simple hydrocarbon looks like this: The equation shows that when propane burns, it uses oxygen and produces carbon dioxide and water. So when a car burns a tank of gas, the amount of CO2 in the atmosphere increases just a little. Added over millions of tanks of gas and coal burned for electricity in power plants and all of the other sources of CO2 , the result is the increase in atmospheric CO2 seen in the Figure 1.2. The second largest source of atmospheric CO2 is deforestation (Figure 1.3). Trees naturally absorb CO2 while they are alive. Trees that are cut down lose their ability to absorb CO2 . If the tree is burned or decomposes, it becomes a source of CO2 . A forest can go from being a carbon sink to being a carbon source. This forest in Mexico has been cut down and burned to clear forested land for agri- culture. "
"on mauna loa volcano in the pacific ocean, co2 content has changed from __________ in 1958 to around __________ in 2014.",(A) 316 ppm; 400 ppm (B) 316 ppm; 350 ppm (C) 416 ppm; 420 ppm (D) 416 ppm; 500 ppm,A,"Remember that the amount of CO2 in the atmosphere is very low. This means that a small increase or decrease in the atmospheric CO2 can have a large effect. By measuring the composition of air bubbles trapped in glacial ice, scientists can learn the amount of atmospheric CO2 at times in the past. Of particular interest is the time just before the Industrial Revolution, when society began to use fossil fuels. That value is thought to be the natural content of CO2 for this time period; that number was 280 parts per million (ppm). By 1958, when scientists began to directly measure CO2 content from the atmosphere at Mauna Loa volcano in the Pacific Ocean, the amount was 316 ppm (Figure 1.2). In 2014, the atmospheric CO2 content had risen to around 400 ppm. The amount of CO2 in the atmosphere has been measured at Mauna Loa Obser- vatory since 1958. The blue line shows yearly averaged CO2 . The red line shows seasonal variations in CO2 . This is an increase in atmospheric CO2 of 40% since the before the Industrial Revolution. About 65% of that increase has occurred since the first CO2 measurements were made on Mauna Loa Volcano, Hawaii, in 1958. "
most air pollutants come from,(A) Burning fossil fuels (B) Solar panels (C) Wind turbines (D) None of the above,A,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
emission control devices placed on power plants to comply with the clean air act have ______________________________ coming from a smokestack.,(A) Reduced the amount of greenhouse gases coming (B) Increased the amount of acid rain-causing chemicals (C) Reduced the amount of pollution that we see (D) All of the above,C,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
nearly half of all air pollution comes from,(A) Factories (B) Power plants (C) Transportation (D) Burning wood,C,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
if fossil fuels like coal and petroleum are not pure they may,(A) Produce only greenhouse gases (B) Produce more pollutants (C) Produce more ozone directly (D) All of these,B,"Fossil fuels are burned in most motor vehicles and power plants. These non-renewable resources are the power for nearly all manufacturing and other industries. Pure coal and petroleum can burn cleanly and emit only carbon dioxide and water, but most of the time these fossil fuels do not burn completely and the incomplete chemical reactions produce pollutants. Few sources of these fossil fuels are pure, so other pollutants are usually released. These pollutants include carbon monoxide, nitrogen dioxide, sulfur dioxide, and hydrocarbons. In large car-dependent cities such as Los Angeles and Mexico City, 80% to 85% of air pollution is from motor vehicles (Figure 1.1). Ozone, carbon monoxide, and nitrous oxides come from vehicle exhaust. Auto exhaust like this means that the fuels is not burning efficiently. A few pollutants come primarily from power plants or industrial plants that burn coal or oil. Sulfur dioxide (SO2 ) is a major component of industrial air pollution that is released whenever coal and petroleum are burned. SO2 mixes with H2 O in the air to produce sulfuric acid (H2 SO4 ). Mercury is released when coal and some types of wastes are burned. Mercury is emitted as a gas, but as it cools, it becomes a droplet. Mercury droplets eventually fall to the ground. If they fall into sediments, bacteria convert them to the most dangerous form of mercury: methyl mercury. Highly toxic, methyl mercury is one of the metals organic forms. "
"when coal is burned, this highly toxic element can also be emitted.",(A) Mercury (B) Sulfur (C) Oxygen (D) Water,A,"Mercury is released into the atmosphere when coal is burned (Figure 1.1). But breathing the mercury is not harmful. In the atmosphere, the mercury forms small droplets that are deposited in water or sediments. "
burning trees produces most of the same pollutants as burning fossil fuels.,(A) True (B) False,A,Millions of acres of forest have been cut and burned to make way for farming. Figure 22.4 shows an example. Burning trees produces most of the same pollutants as burning fossil fuels. 
burning forests increases greenhouse gases by releasing _____________.,(A) Nitrogen (B) Oxygen (C) Methane (D) Carbon dioxide,D,"Human actions are influencing the carbon cycle. Burning of fossil fuels releases the carbon dioxide that was stored in ancient plants. Carbon dioxide is a greenhouse gas and is a cause of global warming. Forests are also being destroyed. Trees may be cut down for their wood, or they may be burned to clear the land for farming. Burning wood releases more carbon dioxide into the atmosphere. You can see how a tropical rainforest was cleared for farming in Figure 18.12. With forests shrinking, there are fewer trees to remove carbon dioxide from the air. This makes the greenhouse effect even worse. "
volatile organic compounds enter the atmosphere by,(A) Evaporation (B) Mixing with water vapor (C) Biomass burning (D) All of the above,A,"Volatile organic compounds (VOCs) enter the atmosphere by evaporation. VOCs evaporate from human-made substances, such as paint thinners, dry cleaning solvents, petroleum, wood preservatives, and other liquids. Naturally occurring VOCs evaporate off of pine and citrus trees. The atmosphere contains tens of thousands of different VOCs, A forest that has been slash-and-burned to make new farmland. nearly 100 of which are monitored. The most common is methane, a greenhouse gas (Figure 1.3). Methane occurs naturally, but human agriculture is increasing the amount of methane in the atmosphere. Methane forms when organic material decomposes in an oxygen-poor environment. In the top image, surface methane production is shown. Stratospheric methane concentrations in the bottom image show that methane is carried up into the stratosphere by the upward flow of air in the tropics. "
slash-and-burn can lead to these pollutants:,(A) Carbon dioxide (B) Methane (C) Particulates (D) All of these,D,Millions of acres of forest have been cut and burned to make way for farming. Figure 22.4 shows an example. Burning trees produces most of the same pollutants as burning fossil fuels. 
which is not a characteristic of all life?,(A) Be organic (B) Have a metabolism (C) Be capable of replication/reproduction (D) Have a heartbeat,D,Five characteristics are used to define life. All living things share these characteristics. All living things: 1. 2. 3. 4. 5. are made of one or more cells. need energy to stay alive. respond to stimuli in their environment. grow and reproduce. maintain a stable internal environment. 
"to learn about the origin of life, scientists do not",(A) Perform experiments to recreate the environmental conditions found at that time (B) Create stories from their imaginations (C) Study organisms living in extreme environments (D) Study ancient microorganisms,B,"To look for information regarding the origin of life, scientists: perform experiments to recreate the environmental conditions found at that time. study the living creatures that make their homes in the types of extreme environments that were typical in Earths early days. seek traces of life left by ancient microorganisms, also called microbes, such as microscopic features or isotopic ratios indicative of life. Any traces of life from this time period are so ancient it is difficult to be certain whether they originated by biological or non-biological means. Click image to the left or use the URL below. URL: "
amino acids are the building blocks of life because they create,(A) Proteins (B) Lipids (C) Carbohydrates (D) Sucrose,A,"Amino acids are the building blocks of life because they create proteins. To form proteins, the amino acids are linked together by covalent bonds to form polymers called polypeptide chains (Figure 1.1). These chains are arranged in a specific order to form each different type of protein. Proteins are the most abundant class of biological molecules. An important question facing scientists is where the first amino acids came from: did they originate on Earth or did they fly in from outer space? No matter where they originated, the creation of amino acids requires the right starting materials and some energy. "
amino acids are linked together by ionic bonds to form monomers called polypeptides.,(A) True (B) False,B,"Amino acids are the building blocks of life because they create proteins. To form proteins, the amino acids are linked together by covalent bonds to form polymers called polypeptide chains (Figure 1.1). These chains are arranged in a specific order to form each different type of protein. Proteins are the most abundant class of biological molecules. An important question facing scientists is where the first amino acids came from: did they originate on Earth or did they fly in from outer space? No matter where they originated, the creation of amino acids requires the right starting materials and some energy. "
what did the miller-urey experiment help determine?,(A) To see if carbohydrates could originate in an early Earth environment (B) To see if amino acids landed on Earth from outer space (C) To see if amino acids could originate in an early Earth environment (D) To see if hydrogen was the first building block of proteins before amino acids,C,"After Einstein proposed his theory, evidence was discovered to support it. For example, scientists shone laser light through two slits in a barrier made of a material that blocked light. You can see the setup of this type of experiment in the Figure 1.2. Using a special camera that was very sensitive to light, they took photos of the light that passed through the slits. The photos revealed tiny pinpoints of light passing through the double slits. This seemed to show that light consists of particles. However, if the camera was exposed to the light for a long time, the pinpoints accumulated in bands that resembled interfering waves. Therefore, the experiment showed that light seems to consist of particles that act like waves. "
"in the miller-urey experiment, electric sparks provided the energy that drove the chemical reactions.",(A) True (B) False,A,"You have probably used activation energy to start a chemical reaction. For example, if youve ever struck a match to light it, then you provided the activation energy needed to start a combustion reaction. When you struck the match on the box, the friction started the match head burning. Combustion is exothermic. Once a match starts to burn, it releases enough energy to activate the next reaction, and the next, and so on. However, the match wont burst into flames on its own. "
scientists think that life on earth originated once.,(A) True (B) False,B,"No one knows how or when life first began on the turbulent early Earth. There is little hard evidence from so long ago. Scientists think that it is extremely likely that life began and was wiped out more than once; for example, by the impact that created the Moon. This issue of whats living and whats not becomes important when talking about the origin of life. If were going to know when a blob of organic material crossed over into being alive, we need to have a definition of life. "
proteins are important because they,(A) Were the living organisms to originate on Earth (B) Are the most abundant class of biological molecules (C) Are known to have originated in outer space (D) rather than on Earth (E) d All of these,B,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
early amino acids may have originated,(A) At hydrothermal vents (B) Deep in the crust (C) Elsewhere in the solar system (D) All of these,D,"To see if amino acids could originate in the environment thought to be present in the first years of Earths existence, Stanley Miller and Harold Urey performed a famous experiment in 1953. To simulate the early atmosphere they Amino acids form polypeptide chains. The setup of the Miller-Urey experiment. placed hydrogen, methane, and ammonia in a flask of heated water that created water vapor, which they called the primordial soup. Sparks simulated lightning, which the scientists thought could have been the energy that drove the chemical reactions that created the amino acids. It worked! The gases combined to form water-soluble organic compounds including amino acids. Amino acids might also have originated at hydrothermal vents or deep in the crust where Earths internal heat is the energy source. Meteorites containing amino acids currently enter the Earth system and so meteorites could have delivered amino acids to the planet from elsewhere in the solar system (where they would have formed by processes similar to those outlined here). "
a primary protein structure is a sequence of a chain of amino acids.,(A) True (B) False,A,"Amino acids are the building blocks of proteins. There are 20 different amino acids. The structural formula of the simplest amino acid, called glycine, is shown in the Figure 1.1. Other amino acids have slightly different structures. A protein molecule is made from one or more long chains of amino acids, each linked to its neighbors by covalent bonds. If a protein has more than one chain, the chains are held together by weaker bonds, such as hydrogen bonds. The sequence of amino acids in chains and the number of chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. Click image to the left or use the URL below. URL:  Q: What do you think the ribbons in the colorful hemoglobin molecule pictured in the opening image represent? A: The ribbons represent chains of amino acids. "
"in chemical bonds,",(A) One or more atoms share electrons (B) Ions join together to create atoms (C) Ions join together to create molecules (D) None of these,C,A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds. Q: Why do you think that chemical bonds form? A: Chemical bonds form because they give atoms a more stable arrangement of electrons. 
an atom that shares one or more electrons with another atom is a(n),(A) Ionic Bond (B) Covalent Bond (C) Hydrogen Bond (D) None of the above,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
a polar molecule is slightly positive on one side and slightly negative on the other.,(A) True (B) False,A,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
water is good at dissolving things because it exhibits,(A) Ionic bonding (B) Covalent bonding (C) Hydrogen bonding (D) All of the above,C,"Remember that H2 O is a polar molecule, so it can dissolve many substances (Figure 1.1). Salts, sugars, acids, bases, and organic molecules can all dissolve in water. "
table salt is an example of hydrogen bonding in which sodium is positive and chlorine is negative.,(A) True (B) False,B,"An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. Figure 7.3 shows how this happens. In row 1 of Figure 7.3, an atom of sodium donates an electron to an atom of chlorine (Cl). By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na+ . By gaining an electron, the chlorine atom becomes a chloride ion. It now has one more electron than protons, giving it a charge of -1. Negative ions are named by adding the suffix ide to the first part of the element name. The symbol for chloride is Cl . Sodium and chloride ions have equal but opposite charges. Opposites attract, so sodium and chloride ions attract each other. They cling together in a strong ionic bond. You can see this in row 2 of Figure 7.3. Brackets separate the ions in the diagram to show that the ions in the compound do not share electrons. You can see animations of sodium chloride forming at these URLs: http://web.jjay.cuny.edu/~acarpi/NSC/salt.htm "
covalent bonds are weak; it does not take a lot of energy to break them apart.,(A) True (B) False,B,"Covalent compounds have different properties than ionic compounds because of their bonds. Covalent compounds exist as individual molecules rather than crystals. It takes less energy for individual molecules than ions in a crystal to pull apart. As a result, covalent compounds have lower melting and boiling points than ionic compounds. Many are gases or liquids at room temperature. Covalent compounds have shared electrons. These are not free to move like the transferred electrons of ionic compounds. This makes covalent compounds poor conductors of electricity. Many covalent compounds also do not dissolve in water as all ionic compounds do. "
"in the compound methane,",(A) Carbon gives an electron to each of four hydrogen ions as an example of covalent bonding (B) Carbon gives an electron to each of four hydrogen ions as an example of ionic bonding (C) Carbon shares an electron with each of four hydrogen ions as an example of ionic bonding (D) Carbon shares an electron with each of four hydrogen ions as an example of covalent,D,Natural gas is mostly methane. 
when a lithium ion and a fluorine ion combine,(A) Lithium donates an electron to fluorine (B) Lithium receives an electron from fluorine (C) Lithium’s positive side and fluorine’s negative side form a hydrogen bond (D) They form a very strong covalent bond,A,"Ionic bonds form only between metals and nonmetals. Metals ""want"" to give up electrons, and nonmetals ""want"" to gain electrons. Find sodium (Na) in Figure 7.4. Sodium is an alkali metal in group 1. Like other group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level. Now find fluorine (F) in Figure 7.4. Fluorine is a halogen in group 17. It has seven valence electrons. If fluorine gains one electron, it will have a full outer energy level. After sodium gives up its valence electron to fluorine, both atoms have a more stable arrangement of electrons. "
water forms droplets because a hydrogen bond is a strong bond.,(A) True (B) False,B,"Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weak as chemical bonds go. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds. Click image to the left or use the URL below. URL: "
"elements on the left side of the periodic table are electron donors, while those on the right side are electron acceptors.",(A) True (B) False,A,"From left to right across the periodic table, each element has one more proton than the element to its left. Because atoms are always electrically neutral, for each added proton, one electron is also added. Electrons are added first to the lowest energy level possible until that level is full. Only then are electrons added to the next higher energy level. "
it is easier and cheaper to clean up groundwater than to prevent it.,(A) True (B) False,B,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
cleaning an aquifer does no good if you do not also,(A) Eliminate the pollution source (B) Stop using the groundwater as a water source (C) Drill test wells (D) All of the above,A,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
"to do chemical remediation of an acidic pollutant in an aquifer, introduce",(A) A safe acidic compound (B) A safe basic compound (C) A safe neutral compound (D) None of the above,B,"First, an underground barrier is constructed to isolate the contaminated groundwater from the rest of the aquifer. Next, the contaminated groundwater may be treated in place. Bioremediation is relatively inexpensive. Bioengineered microorganisms are injected into the contaminant plume and allowed to consume the pollutant. Air may be pumped into the polluted region to encourage the growth and reproduction of the microbes. With chemical remediation, a chemical is pumped into the aquifer so the contaminant is destroyed. Acids or bases can neutralize contaminants or cause pollutants to precipitate from the water. The most difficult and expensive option is for reclamation teams to pump the water to the surface, cleanse it using chemical or biological methods, then re-inject it into the aquifer. The contaminated portions of the aquifer must be dug up and the pollutant destroyed by incinerating or chemically processing the soil, which is then returned to the ground. This technique is often prohibitively expensive and is done only in extreme cases. Click image to the left or use the URL below. URL: "
this form of remediation involves injecting microorganisms into the contaminant plume and allowing them to consume the pollutant.,(A) Chemical remediation (B) Contaminant remediation (C) Pollution remediation (D) Bioremediation,D,"First, an underground barrier is constructed to isolate the contaminated groundwater from the rest of the aquifer. Next, the contaminated groundwater may be treated in place. Bioremediation is relatively inexpensive. Bioengineered microorganisms are injected into the contaminant plume and allowed to consume the pollutant. Air may be pumped into the polluted region to encourage the growth and reproduction of the microbes. With chemical remediation, a chemical is pumped into the aquifer so the contaminant is destroyed. Acids or bases can neutralize contaminants or cause pollutants to precipitate from the water. The most difficult and expensive option is for reclamation teams to pump the water to the surface, cleanse it using chemical or biological methods, then re-inject it into the aquifer. The contaminated portions of the aquifer must be dug up and the pollutant destroyed by incinerating or chemically processing the soil, which is then returned to the ground. This technique is often prohibitively expensive and is done only in extreme cases. Click image to the left or use the URL below. URL: "
which form of remediation involves pumping a chemical into an aquifer to destroy a contaminant?,(A) Bioremediation (B) Chemical remediation (C) Contaminant remediation (D) Pollution remediation,B,"First, an underground barrier is constructed to isolate the contaminated groundwater from the rest of the aquifer. Next, the contaminated groundwater may be treated in place. Bioremediation is relatively inexpensive. Bioengineered microorganisms are injected into the contaminant plume and allowed to consume the pollutant. Air may be pumped into the polluted region to encourage the growth and reproduction of the microbes. With chemical remediation, a chemical is pumped into the aquifer so the contaminant is destroyed. Acids or bases can neutralize contaminants or cause pollutants to precipitate from the water. The most difficult and expensive option is for reclamation teams to pump the water to the surface, cleanse it using chemical or biological methods, then re-inject it into the aquifer. The contaminated portions of the aquifer must be dug up and the pollutant destroyed by incinerating or chemically processing the soil, which is then returned to the ground. This technique is often prohibitively expensive and is done only in extreme cases. Click image to the left or use the URL below. URL: "
a problem with having to bring toxic materials to the surface to cleanse them is,(A) How to re-inject the cleansed rock and soil back into the aquifer (B) Where to do the bioremediation on the toxic materials (C) Where to dispose of the toxic materials (D) None of these,C,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
"if you pumped contaminated water from an aquifer, cleaned the water and pumped it back in what would happen?",(A) The water would be clean and stay clean (B) The water would clean the aquifer (C) The water would be re-contaminated by the aquifer (D) It’s impossible to know what would happen,C,"When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated. In Florida, for example, more than 90% of wells have detectible contaminants and thousands have been closed. "
the most dangerous contaminants in water are the ones that are visible.,(A) True (B) False,B,"Factories and power plants may pollute water with harmful substances. Many industries produce toxic chemicals. Some of the worst are arsenic, lead, and mercury. Nuclear power plants produce radioactive chemicals. They cause cancer and other serious health problems. Oil tanks and pipelines can leak. Leaks may not be noticed until a lot of oil has soaked into the ground. The oil may pollute groundwater so it is no longer fit to drink. "
pumping water to the surface to clean the pollutant is more expensive than in situ cleaning methods because the soil and rock must be cleaned too.,(A) True (B) False,A,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
"throughout earths history, its climate has always been colder and less humid than it is today.",(A) True (B) False,B,Earths climate has changed many times through Earths history. Its been both hotter and colder than it is today. 
glaciers during the pleistocene,(A) Advanced and retreated in cycles (B) There were glacial and interglacial periods (C) Bound up a lot of Earth’s water into ice (D) All of the above,D,"As the continents moved apart, climate began to cool. When Australia and Antarctica separated, the Antarctic Circumpolar Current could then move the frigid water around Antarctica and spread it more widely around the planet. Antarctica drifted over the south polar region and the continent began to grow a permanent ice cap in the Oligocene. The climate warmed in the early Miocene but then began to cool again in the late Miocene and Pliocene when glaciers began to form. During the Pleistocene ice ages, which began 2.6 million years ago, glaciers advanced and retreated four times (Figure 1.2). During the retreats, the climate was often warmer than it is today. Glacial ice at its maximum during the Pleistocene. These continental ice sheets were extremely thick, like the Antarctic ice cap is today. The Pleistocene ice ages guided the evolution of life in the Cenozoic, including the evolution of humans. "
the most recent ice age was in the ____________ between __________ years ago.,(A) Pleistocene Epoch; 18 million and 10 (B) 000 (C) b Pleiocene Epoch; 1 million and 10 (D) 000 (E) c Pleistocene Epoch; 18 million and 1 million (F) d Pleiocene Epoch; 2 million and 1 million,A,"The last major ice age took place in the Pleistocene. This epoch lasted from 2 million to 14,000 years ago. Earths temperature was only 5 C (9 F) cooler than it is today. But glaciers covered much of the Northern Hemisphere. In Figure 17.17, you can see how far south they went. Clearly, a small change in temperature can have a big impact on the planet. Humans lived during this ice age. "
the average global temperature during glacial periods was __________ less than current average global temperature.,(A) 105 oC (189oF) (B) 55 oC (10oF) (C) 20oC (36oF) (D) 82 oC (148oF),B,"Climate has changed throughout Earth history. Much of the time Earths climate was hotter and more humid than it is today, but climate has also been colder, as when glaciers covered much more of the planet. The most recent ice ages were in the Pleistocene Epoch, between 1.8 million and 10,000 years ago (Figure 1.1). Glaciers advanced and retreated in cycles, known as glacial and interglacial periods. With so much of the worlds water bound into the ice, sea level was about 125 meters (395 feet) lower than it is today. Many scientists think that we are now in a warm, interglacial period that has lasted about 10,000 years. For the past 1500 years, climate has been relatively mild and stable when compared with much of Earths history. Why has climate stability been beneficial for human civilization? Stability has allowed the expansion of agriculture and the development of towns and cities. Fairly small temperature changes can have major effects on global climate. The average global temperature during glacial periods was only about 5.5o C (10o F) less than Earths current average temperature. Temperatures during the interglacial periods were about 1.1o C (2.0o F) higher than today (Figure 1.2). The maximum extent of Northern Hemi- sphere glaciers during the Pleistocene epoch. Since the end of the Pleistocene, the global average temperature has risen about 4o C (7o F). Glaciers are retreating and sea level is rising. While climate is getting steadily warmer, there have been a few more extreme warm and cool times in the last 10,000 years. Changes in climate have had effects on human civilization. The Medieval Warm Period from 900 to 1300 A.D. allowed Vikings to colonize Greenland and Great Britain to grow wine grapes. The Little Ice Age, from the 14th to 19th centuries, the Vikings were forced out of Greenland and humans had to plant crops further south. The graph is a compilation of 5 recon- structions (the green line is the mean of the five records) of mean temperature changes. This illustrates the high tem- peratures of the Medieval Warm Period, the lows of the Little Ice Age, and the very high (and climbing) temperature of this decade. Click image to the left or use the URL below. URL: "
"when glaciers retreat, sea level rises.",(A) True (B) False,A,"Because of global climate change, temperatures all over Earth are rising. However, the melting points of Earths substances, including ice, are constant. The result? Glaciers are melting at an alarming rate. Melting glaciers cause rising sea levels and the risk of dangerous river flooding on land. Click image to the left or use the URL below. URL: "
fairly small changes in temperature can have major effects on global climate.,(A) True (B) False,A,"Several natural processes may affect Earths temperature. They range from sunspots to Earths wobble. Sunspots are storms on the Sun. When the number of sunspots is high, the Sun gives off more energy than usual. Still, there is little evidence for climate changing along with the sunspot cycle. Plate movements cause continents to drift closer to the poles or the equator. Ocean currents also shift when continents drift. All these changes can affect Earths temperature. Plate movements trigger volcanoes. A huge eruption could spew so much gas and ash into the air that little sunlight would reach the surface for months or years. This could lower Earths temperature. A large asteroid hitting Earth would throw a lot of dust into the air. This could block sunlight and cool the planet. Earth goes through regular changes in its position relative to the Sun. Its orbit changes slightly. Earth also wobbles on its axis of rotation. The planet also changes the tilt on its axis. These changes can affect Earths temperature. "
how is climate stability beneficial to the human civilization?,(A) It allows the expansion of agriculture (B) It allows the development of towns and cities (C) It has allowed development along coastlines over the centuries (D) All of the above,D,"Climate has changed throughout Earth history. Much of the time Earths climate was hotter and more humid than it is today, but climate has also been colder, as when glaciers covered much more of the planet. The most recent ice ages were in the Pleistocene Epoch, between 1.8 million and 10,000 years ago (Figure 1.1). Glaciers advanced and retreated in cycles, known as glacial and interglacial periods. With so much of the worlds water bound into the ice, sea level was about 125 meters (395 feet) lower than it is today. Many scientists think that we are now in a warm, interglacial period that has lasted about 10,000 years. For the past 1500 years, climate has been relatively mild and stable when compared with much of Earths history. Why has climate stability been beneficial for human civilization? Stability has allowed the expansion of agriculture and the development of towns and cities. Fairly small temperature changes can have major effects on global climate. The average global temperature during glacial periods was only about 5.5o C (10o F) less than Earths current average temperature. Temperatures during the interglacial periods were about 1.1o C (2.0o F) higher than today (Figure 1.2). The maximum extent of Northern Hemi- sphere glaciers during the Pleistocene epoch. Since the end of the Pleistocene, the global average temperature has risen about 4o C (7o F). Glaciers are retreating and sea level is rising. While climate is getting steadily warmer, there have been a few more extreme warm and cool times in the last 10,000 years. Changes in climate have had effects on human civilization. The Medieval Warm Period from 900 to 1300 A.D. allowed Vikings to colonize Greenland and Great Britain to grow wine grapes. The Little Ice Age, from the 14th to 19th centuries, the Vikings were forced out of Greenland and humans had to plant crops further south. The graph is a compilation of 5 recon- structions (the green line is the mean of the five records) of mean temperature changes. This illustrates the high tem- peratures of the Medieval Warm Period, the lows of the Little Ice Age, and the very high (and climbing) temperature of this decade. Click image to the left or use the URL below. URL: "
the vikings colonized greenland during this period __________ and were forced out during this period __________.,(A) The Little Ice Age; the Medieval Warm Period (B) The Late Ice Age; the Middle Warm Period (C) The Medieval Warm Period; the Little Ice Age (D) The Middle Warm Period; The Late Ice Age,C,"During the Quaternary Period, the climate cooled. This caused a series of ice ages. Glaciers advanced southward from the North Pole. They reached as far south as Chicago and New York City. Sea levels fell because so much water was frozen in glaciers. This exposed land bridges between continents. The land bridges allowed land animals to move to new areas. Some mammals adapted to the cold by evolving very large size and thick fur. An example is the woolly mammoth, shown in Figure 7.25. Other mammals moved closer to the equator. Those that couldnt adapt or move went extinct, along with many plants. The last ice age ended about 12,000 years ago. By then, our own species, Homo sapiens, had evolved. After that, we were eyewitnesses to the story of life. As a result, the recent past is less of a mystery than the billions of years before it. "
"since the end of the ice ages, temperature had been getting steadily warmer, although not uniformly warmer.",(A) True (B) False,A,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
the message of this concept is,(A) Climate has changed throughout earth history (B) Human civilization depends on a fairly stable climate (C) Climate in the past 15 centuries or so has been fairly stable (D) All of these,D,Two important concepts associated with the ecosystem are niche and habitat. 
climate zones are,(A) The same at similar latitudes (B) in similar positions on nearly all continents (C) b The same across the Northern Hemisphere but not the Southern Hemisphere (D) c Different even at similar latitudes and in similar positions (E) d Random,A,"Climate zones are classified by the Kppen classification system. This system is based on the temperature, the amount of precipitation, and the times of year when precipitation occurs. Since climate determines the type of vegetation that grows in an area, vegetation is used as an indicator of climate type. "
biomes are made up of _____________.,(A) Climate type (B) Plants (C) Animals (D) All of the above,D,"Plants are the primary producers in terrestrial biomes. They make food for themselves and other organisms by photosynthesis. The major plants in a given biome, in turn, help determine the types of animals and other organisms that can live there. Which plants grow in a given biome depends mainly on climate. Climate is the average weather in a place over a long period of time. The major climatic factors affecting plant growth are temperature and moisture. "
climate zones are classified by,(A) The type of vegetation that occurs (B) A climate type and its plants and animals (C) Temperature (D) amount of precipitation (E) and time of year of precipitation (F) d None of the above,C,"Climate zones are classified by the Kppen classification system. This system is based on the temperature, the amount of precipitation, and the times of year when precipitation occurs. Since climate determines the type of vegetation that grows in an area, vegetation is used as an indicator of climate type. "
"plants that live in the same biome, but on different continents, share the same characteristics.",(A) True (B) False,A,"A climate type and its plants and animals make up a biome. The organisms of a biome share certain characteristics around the world, because their environment has similar advantages and challenges. The organisms have adapted to that environment in similar ways over time. For example, different species of cactus live on different continents, but they have adapted to the harsh desert in similar ways. Click image to the left or use the URL below. URL: "
dry climates,(A) Are arid (B) but they still have more precipitation than evaporation (C) b Have little rainfall (D) but what comes falls regularly throughout the year (E) c Have hot summers and extremely warm winters (F) d Are located at around 30o N where air descends in the global circulation cells,D,Dry climates have less precipitation than evaporation. Temperature: Abundant sunshine. Summer temperatures are high; winters are cooler and longer than in tropical moist climates. Rainfall: Irregular; several years of drought are often followed by a single year of abundant rainfall. Dry climates cover about 26% of the worlds land area. Low latitude deserts are found at the Ferrell cell high pressure zone. Higher latitude deserts occur within continents or in rainshadows. Vegetation is sparse but well adapted to the dry conditions. 
the moist subtropical mid-latitude climate zones are found along the coastal areas in the united states.,(A) True (B) False,A,"Moist subtropical mid-latitude climates are found along the coastal areas in the United States. Temperature: The coldest month ranges from just below freezing to almost balmy, between -3o C and 18o C (27o to 64o F). Summers are mild, with average temperatures above 10o C (50o F). Seasons are distinct. Rainfall: There is plentiful annual rainfall. "
most precipitation in the polar climates occurs in the summer.,(A) True (B) False,A,"Polar climates are found across the continents that border the Arctic Ocean, Greenland, and Antarctica. Temperature: Winters are entirely dark and bitterly cold. Summer days are long, but the Sun is low on the horizon so summers are cool. The average temperature of the warmest month is less than 10o C (50o F). The annual temperature range is large. Precipitation: The region is dry, with less than 25 cm (10 inches) of precipitation annually; most precipitation occurs during the summer. "
microclimates have,(A) The same climates as the surrounding region (B) A different climates than the surrounding region (C) A more extreme climate than the surrounding region (D) None of the above,B,"When climate conditions in a small area are different from those of the surroundings, the climate of the small area is called a microclimate. The microclimate of a valley may be cool relative to its surroundings since cold air sinks. The ground surface may be hotter or colder than the air a few feet above it, because rock and soil gain and lose heat readily. Different sides of a mountain will have different microclimates. In the Northern Hemisphere, a south-facing slope receives more solar energy than a north-facing slope, so each side supports different amounts and types of vegetation. Altitude mimics latitude in climate zones. Climates and biomes typical of higher latitudes may be found in other areas of the world at high altitudes. Click image to the left or use the URL below. URL: "
which of the following is not a characteristic of continental climates?,(A) Winters are cold and stormy (B) Summers are hot (C) They are found at 40oN to 70oN and 40oS to 70oS (D) The average annual temperature is fairly mild,C,"Continental climates are found in inland areas. They are too far from oceans to experience the effects of ocean water. Continental climates are common between 40 and 70 north latitude. There are no continental climates in the Southern Hemisphere. Can you guess why? The southern continents at this latitude are too narrow. All of their inland areas are close enough to a coast to be affected by the ocean! Humid continental climates are found between 40 and 60 north latitude. The northeastern U.S. has this type of climate. Summers are warm to hot, and winters are cold. Precipitation is moderate, and it falls year round. Deciduous trees grow in this climate. They lose their leaves in the fall and grow new ones in the spring. Subarctic climates are found between 60 and 70 north latitude. Much of Canada and Alaska have this type of climate. Summers are cool and short. Winters are very cold and long. Little precipitation falls, and most of it falls during the summer. Conifer forests grow in this climate (see Figure 17.13). "
the solid form of hydrocarbon is __________________.,(A) Natural Gas (B) Coal (C) Petroleum (D) Fossil fuel,B,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
which of these statements are true about coal?,(A) Coal is useful as fuel (B) Coal helps generate electricity (C) Coal is a sedimentary or metamorphic rock (D) All of the above,D,"Coal is a black or brownish-black rock that burns easily (Figure 5.3). Most coal is sedimentary rock. The hardest type of coal, anthracite, is a metamorphic rock. That is because it is exposed to higher temperature and pressure as it forms. Coal is mostly carbon, but some other elements can be found in coal, including sulfur. "
what is coal made from?,(A) Dead plant matter that settled at the bottom of swamps millions of years ago (B) Heated rock from the sun (C) Volcanic Lava (D) None of the above,A,"Coal, a solid fossil fuel formed from the partially decomposed remains of ancient forests, is burned primarily to produce electricity. Coal use is undergoing enormous growth as the availability of oil and natural gas decreases and cost increases. This increase in coal use is happening particularly in developing nations, such as China, where coal is cheap and plentiful. Coal is black or brownish-black. The most common form of coal is bituminous, a sedimentary rock that contains impurities such as sulfur (Figure 1.1). Anthracite coal has been metamorphosed and is nearly all carbon. For this reason, anthracite coal burns more cleanly than bituminous coal. "
"for coal to form, during burial the organic matter must be kept away from nitrogen.",(A) True (B) False,B,"Coal forms from dead plants that settled at the bottom of ancient swamps. Lush coal swamps were common in the tropics during the Carboniferous period, which took place more than 300 million years ago (Figure 1.2). The climate was warmer then. Mud and other dead plants buried the organic material in the swamp, and burial kept oxygen away. When plants are buried without oxygen, the organic material can be preserved or fossilized. Sand and clay settling on top of the decaying plants squeezed out the water and other substances. Millions of years later, what remains is a carbon- containing rock that we know as coal. "
"most coal in the united states, and worldwide, is this type",(A) Anthracite (B) Bituminous (C) Subbituminous (D) Lignite,B,"Around the world, coal is the largest source of energy for electricity. The United States is rich in coal (Figure 1.3). California once had a number of small coal mines, but the state no longer produces coal. To turn coal into electricity, the rock is crushed into powder, which is then burned in a furnace that has a boiler. Like other fuels, coal releases its energy as heat when it burns. Heat from the burning coal boils the water in the boiler to make steam. The steam spins turbines, which turn generators to create electricity. In this way, the energy stored in the coal is converted to useful energy like electricity. "
anthracite is this type of rock.,(A) Sedimentary (B) Igneous (C) Metamorphic (D) All of the above,C,"Coal is a black or brownish-black rock that burns easily (Figure 5.3). Most coal is sedimentary rock. The hardest type of coal, anthracite, is a metamorphic rock. That is because it is exposed to higher temperature and pressure as it forms. Coal is mostly carbon, but some other elements can be found in coal, including sulfur. "
"coal mining exposes this element, which when mixed with air and water makes a highly corrosive chemical.",(A) Sulfur (B) Oxygen (C) Carbon (D) Methane,A,"For coal to be used as an energy source, it must first be mined. Coal mining occurs at the surface or underground by methods that are described in the the chapter Materials of Earths Crust (Figure 1.4). Mining, especially underground The location of the continents during the Carboniferous period. Notice that quite a lot of land area is in the region of the tropics. mining, can be dangerous. In April 2010, 29 miners were killed at a West Virginia coal mine when gas that had accumulated in the mine tunnels exploded and started a fire. Coal mining exposes minerals and rocks from underground to air and water at the surface. Many of these minerals contain the element sulfur, which mixes with air and water to make sulfuric acid, a highly corrosive chemical. If the sulfuric acid gets into streams, it can kill fish, plants, and animals that live in or near the water. Click image to the left or use the URL below. URL: "
coal formed in ancient swamps especially during this period.,(A) Cambrian (B) Precambrian (C) Mesozoic (D) Carboniferous,D,"Coal forms from dead plants that settled at the bottom of ancient swamps. Lush coal swamps were common in the tropics during the Carboniferous period, which took place more than 300 million years ago (Figure 1.2). The climate was warmer then. Mud and other dead plants buried the organic material in the swamp, and burial kept oxygen away. When plants are buried without oxygen, the organic material can be preserved or fossilized. Sand and clay settling on top of the decaying plants squeezed out the water and other substances. Millions of years later, what remains is a carbon- containing rock that we know as coal. "
coal that forms at higher temperatures burns more cleanly.,(A) True (B) False,A,"Gasification is a developing technology. In gasification, coal (rarely is another organic material used) is heated to extremely high temperatures to create syngas, which is then filtered. The energy goes on to drive a generator. Syngas releases about 80% less pollution than regular coal plants, and greenhouse gases are also lower. Clean coal plants do not need scrubbers or other pollution control devices. Although the technology is ready, clean coal plants are more expensive to construct and operate. Also, heating the coal to high enough temperatures uses a great deal of energy, so the technology is not energy efficient. In addition, large amounts of the greenhouse gas CO2 are still released with clean coal technology. Nonetheless, a few of these plants are operating in the United States and around the world. "
how does burning coal make electricity?,(A) Heat boils water to make steam (B) turns generators (C) spins turbines (D) make electricity (E) b Creates elements that combine to release radioactive material that spins turbines (F) turns generators (G) make electricity (H) c Heat boils water to make steam (I) spins turbines (J) turns generators (K) make electricity (L) d None of these,C,"To prepare coal for use, the coal is first crushed into powder and burned in a furnace. Like other fuels, coal releases most of its energy as heat when it burns. The heat from the burning coal is used to boil water. This makes steam. The steam spins turbines, which creates electricity. "
"this contaminant gets washed from farms and yards into rivers, causing algae to grow.",(A) Toxins (B) Pesticides (C) Fertilizers (D) All of the above,C,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
___________ can become runoff that travels from the land to the ocean where it becomes a marine pollutant.,(A) Agricultural waste (B) Industrial waste (C) Municipal waste (D) All of the above,D,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
most ocean pollution comes from runoff while the remaining 20% of water pollution comes from __________.,(A) Oil spills (B) People dumping wastes directly in water (C) Both a and b (D) None of the above,C,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
humans can be affected by ocean pollution when they,(A) Eat contaminated fish (B) Swim in contaminated water (C) Engage in ocean sports (D) All of the above,D,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
fertilizers create dead zones when,(A) They cause the algae population to explode (B) They cause the fish population to explode (C) They take all the oxygen out of the water (D) None of these,A,"Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. Every year dead zones appear in lakes and nearshore waters. A dead zone is an area of hundreds of kilometers of ocean without fish or plant life. The Mississippi is not the only river that carries the nutrients necessary to cause a dead zone. Rivers that drain regions where human population density is high and where crops are grown create dead zones all over the world (Figure 1.2). "
most ocean pollution comes from land and is found in or near coastal regions.,(A) True (B) False,A,"The oceans are most polluted along coasts. Why do you think thats the case? Of course, its because most pollution enters the oceans from the land. Runoff and rivers carry the majority of pollution into the ocean. Many cities dump their wastewater directly into coastal waters. In some parts of the world, raw sewage and trash may be thrown into the water (see Figure 21.12). Coastal water may become so polluted that people get sick if they swim in it or eat seafood from it. The polluted water may also kill fish and other ocean life. "
"fish are affected by oceanic pollutants, but humans are not affected because they do not live in the ocean.",(A) True (B) False,B,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
in what ways do fish rely on coastal wetlands?,(A) For food (B) To lay their eggs (C) Shelter (D) All of the above,D,"For some species, aquaculture is very successful and environmental harm is minimal. But for other species, aqua- culture can cause problems. Natural landscapes, such as mangroves, which are rich ecosystems and also protect coastlines from storm damage, may be lost to fish farms (Figure 1.4). For fish farmers, keeping costs down may be a problem since coastal land may be expensive and labor costs may be high. Large predatory fish at the 4th or 5th trophic level must eat a lot, so feeding large numbers of these fish is expensive and environmentally costly. Farmed fish are genetically different from wild stocks, and if they escape into the wild they may cause problems for native fish. Because the organisms live so close together, parasites are common and may also escape into the wild. Shrimp farms on the coast of Ecuador are shown as blue rectangles. Mangrove forests, salt flats, and salt marshes have been converted to shrimp farms. "
ships at sea treat their wastes and bring their trash back to land for recycling.,(A) True (B) False,B,"Although people had once thought that the trash found everywhere at sea was from ships, it turns out that 80% is from land. Some of that is from runoff, some is blown from nearshore landfills, and some is dumped directly into the sea. The 20% that comes from ships at sea includes trash thrown overboard by large cruise ships and many other vessels. It also includes lines and nets from fishing vessels. Ghost nets, nets abandoned by fishermen intentionally or not, float the seas and entangle animals so that they cannot escape. Containers sometimes go overboard in storms. Some noteworthy events, like a container of rubber ducks that entered the sea in 1992, are used to better understand ocean currents. The ducks went everywhere! "
when do comets have tails?,(A) When they are close to colliding with an asteroid (B) When they are close to the Sun (C) When stars get in their way (D) When they pass Earth,B,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
what causes a comets tail to form?,(A) Ice from the outer layer of the comet vaporizes and reflects sunlight (B) Nuclear fusion in the comet leaves a trail of radiation (C) The comet lights on fire near the sun and leaves a trail of fiery particles behind it (D) None of these,A,"Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This atmosphere is called a coma. Radiation and particles streaming from the Sun push some of this gas and dust into a long tail. A comets tail always points away from the Sun, no matter which way the comet is moving. Why do you think that is? Figure Gases in the coma and tail of a comet reflect light from the Sun. Comets are very hard to see except when they have comas and tails. That is why they appear only when they are near the Sun. They disappear again as they move back to the outer solar system. The time between one visit from a comet and the next is called the comets period. The first comet whose period was known was Halleys Comet. Its period is 75 years. Halleys Comet last traveled through the inner solar system in 1986. The comet will appear again in 2061. Who will look up at it? "
"possibly the most famous comet, halleys, has a period of __________ and will next be seen in __________.",(A) 25 years; 2035 (B) 50 years; 2053 (C) 75 years; 2061 (D) 100 years; 2082,C,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
where do long-period comets come from?,(A) The asteroid belt (B) The Oort cloud (C) The Kuiper belt (D) The comet belt,B,"Short-period comets, with periods of about 200 years or less, come from a region beyond the orbit of Neptune called the Kuiper belt (pronounced KI-per). It contains not only comets, but also asteroids and at least two dwarf planets. Comets with periods as long as thousands or even millions of years come from a very distant region of the solar system called the Oort cloud, about 50,000  100,000 AU from the Sun (50,000 - 100,000 times the distance from the Sun to Earth). Click image to the left or use the URL below. URL: "
where do short-period comets come from?,(A) The asteroid belt (B) The Oort cloud (C) The Kuiper belt (D) The comet belt,C,"Short-period comets, with periods of about 200 years or less, come from a region beyond the orbit of Neptune called the Kuiper belt (pronounced KI-per). It contains not only comets, but also asteroids and at least two dwarf planets. Comets with periods as long as thousands or even millions of years come from a very distant region of the solar system called the Oort cloud, about 50,000  100,000 AU from the Sun (50,000 - 100,000 times the distance from the Sun to Earth). Click image to the left or use the URL below. URL: "
"in the early solar system, comets that struck earth may have brought in",(A) Water (B) Microbes (C) Plankton (D) All of the above,A,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
comets may be visible with the naked eye,(A) During their entire journey around the sun (B) For a short time when they are near the Sun (C) Never (D) None of these,B,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
"without its tail, a comet looks like a ball of ice.",(A) True (B) False,A,"Comets are small, icy objects that have very elliptical orbits around the Sun. Their orbits carry them from the outer solar system to the inner solar system, close to the Sun. Early in Earths history, comets may have brought water and other substances to Earth during collisions. Comet tails form the outer layers of ice melt and evaporate as the comet flies close to the Sun. The ice from the comet vaporizes and forms a glowing coma, which reflects light from the Sun. Radiation and particles streaming from the Sun push this gas and dust into a long tail that always points away from the Sun (Figure 1.1). Comets appear for only a short time when they are near the Sun, then seem to disappear again as they move back to the outer solar system. Comet Hale-Bopp, also called the Great Comet of 1997, shone brightly for several months in 1997. The comet has two visible tails: a bright, curved dust tail and a fainter, straight tail of ions (charged atoms) pointing directly away from the Sun. The time between one appearance of a comet and the next is called the comets period. Halleys comet, with a period of 75 years, will next be seen in 2061. The first mention of the comet in historical records may go back as much as two millennia. "
"the oort cloud is about 50,000-100,000 au from the sun.",(A) True (B) False,A,"Short-period comets, with periods of about 200 years or less, come from a region beyond the orbit of Neptune called the Kuiper belt (pronounced KI-per). It contains not only comets, but also asteroids and at least two dwarf planets. Comets with periods as long as thousands or even millions of years come from a very distant region of the solar system called the Oort cloud, about 50,000  100,000 AU from the Sun (50,000 - 100,000 times the distance from the Sun to Earth). Click image to the left or use the URL below. URL: "
the kuiper belt is home to,(A) Short-period comets (B) Asteroids (C) Dwarf planets (D) All of the above,D,"Some comets have periods of 200 years or less. They are called short-period comets. Short-period comets are from a region beyond the orbit of Neptune called the Kuiper Belt. Kuiper is pronounced KI-per, rhyming with viper. The Kuiper Belt is home to comets, asteroids, and at least two dwarf planets. Some comets have periods of thousands or even millions of years. Most long-period comets come from a very distant region of the solar system. This region is called the Oort cloud. The Oort cloud is about 50,000100,000 times the distance from the Sun to Earth. Comets carry materials in from the outer solar system. Comets may have brought water into the early Earth. Other substances could also have come from comets. "
"plant whatever types of plants you like, no matter where you live.",(A) True (B) False,B,Plants seem to grow wherever they can. How? Plants cant move on their own. So how does a plant start growing in a new area? 
a practical way to conserve water is for farmers to _________.,(A) Use drip irrigation (B) Use sprinklers (C) Only plant on flood plains (D) None of the above,A,"As human population growth continues, water conservation will become increasingly important globally, especially in developed countries where people use an enormous amount of water. What are some of the ways you can conserve water in and around your home? Avoid polluting water so that less is needed. Convert to more efficient irrigation methods on farms and in gardens. Reduce household demand by installing water-saving devices such as low-flow shower heads and toilets. Reduce personal demand by turning off the tap when water is not being used and taking shorter showers. Engage in water-saving practices: for instance, water lawns less and sweep rather than hose down sidewalks. At Earth Summit 2002, many governments approved a Plan of Action to address the scarcity of water and safe drinking water in developing countries. One goal of this plan was to cut in half the number of people without access to safe drinking water by 2015. Although this is a very important goal, it will not be met. Goals like these are made more difficult as population continues to grow. This colorful adobe house in Tucson, Arizona is surrounded by native cactus, which needs little water to thrive. Click image to the left or use the URL below. URL: "
which of these can conserve water in your home?,(A) Have low-flow shower heads (B) Have low-flow toilets (C) Turn off the tap when not being used (D) All of the above,D,"Its easy to save water at home. If you save even a few gallons a day you can make a big difference over the long run. The best place to start saving water is in the bathroom. Toilet flushing is the single biggest use of water in the home. Showers and baths are the next biggest use. Follow the tips below to save water at home. Install water-saving toilets. They use only about half as much water per flush. A single household can save up to 20,000 gallons a year with this change alone! Take shorter showers. You can get just as clean in 5 minutes as you can in 10. And youll save up to 50 gallons of water each time you shower. Thats thousands of gallons each year. Use low-flow shower heads. They use about half as much water as regular shower heads. They save thousands of gallons of water. Fix leaky shower heads and faucets. All those drips really add up. At one drip per second, more than 6,000 gallons go down the drain in a year per faucet! Dont leave the water running while you brush your teeth. You could save as much as 10 gallons each time you brush. That could add up to 10,000 gallons in a year. Landscape your home with plants that need little water. This could result in a huge savings in water use. Look at the garden in Figure 21.20. It shows that you dont have to sacrifice beauty to save water. "
one complication with environmental issues is that,(A) Technology keeps improving (B) People keep thinking of new and better ways to get clean drinking water (C) The human population keeps growing (D) None of these,C,"In addition to habitat destruction, other human-caused problems are also threatening many species. These include issues associated with climate change, pollution, and over-population. "
"at the earth summit in 2002, the plan was to cut in half the number of people without access to safe drinking water by",(A) 2015 (B) 2020 (C) 2025 (D) 2030,A,"As human population growth continues, water conservation will become increasingly important globally, especially in developed countries where people use an enormous amount of water. What are some of the ways you can conserve water in and around your home? Avoid polluting water so that less is needed. Convert to more efficient irrigation methods on farms and in gardens. Reduce household demand by installing water-saving devices such as low-flow shower heads and toilets. Reduce personal demand by turning off the tap when water is not being used and taking shorter showers. Engage in water-saving practices: for instance, water lawns less and sweep rather than hose down sidewalks. At Earth Summit 2002, many governments approved a Plan of Action to address the scarcity of water and safe drinking water in developing countries. One goal of this plan was to cut in half the number of people without access to safe drinking water by 2015. Although this is a very important goal, it will not be met. Goals like these are made more difficult as population continues to grow. This colorful adobe house in Tucson, Arizona is surrounded by native cactus, which needs little water to thrive. Click image to the left or use the URL below. URL: "
lawns and golf courses conserve water because they trap water within them.,(A) True (B) False,B,"There are many ways to use water for fun, from white water rafting to snorkeling. When you do these activities you dont actually use water. You are doing the activity on or in the water. What do you think is the single biggest use of water for fun? Believe it or not, its golf! Keeping golf courses green uses an incredible amount of water. Since many golf courses are in sunny areas, much of the water is irrigation water. Many golf courses, like the one in Figure 21.4, have sprinkler systems. Like any similar sprinkler system, much of this water is wasted. It evaporates or runs off the ground. "
it is better to sweep the sidewalks rather than hosing them down with water.,(A) True (B) False,A,"A little bit of water helps to hold grains of sand or soil together. For example, you can build a larger sand castle with slightly wet sand than with dry sand. However, too much water causes the sand to flow quickly away. Rapid snow melt or rainfall adds extra water to the soil, which increases the weight of the slope and makes sediment grains lose contact with each other, allowing flow. "
careful water use can be encouraged by,(A) Shutting down the water to houses that use too much (B) Giving a financial incentive for reducing water consumption (C) Not worrying about water use since there is plenty (D) None of these,B,"Water consumption per person has been going down for the past few decades. There are many ways that water conservation can be encouraged. Charging more for water gives a financial incentive for careful water use. Water use may be restricted by time of day, season, or activity. Good behavior can be encouraged; for example, people can be given an incentive to replace grass with desert plants in arid regions. "
"it may not seem like much, but putting water on a toothbrush as needed rather than letting the water flow, makes an impact, especially if lots of people do it.",(A) True (B) False,A,"Water consumption per person has been going down for the past few decades. There are many ways that water conservation can be encouraged. Charging more for water gives a financial incentive for careful water use. Water use may be restricted by time of day, season, or activity. Good behavior can be encouraged; for example, people can be given an incentive to replace grass with desert plants in arid regions. "
the coast of south america fits closely to this continent like a puzzle piece.,(A) Africa (B) North America (C) Europe (D) Asia,A,"Oceanic crust may collide with a continent. The oceanic plate is denser, so it undergoes subduction. This means that the oceanic plate sinks beneath the continent. This occurs at an ocean trench (Figure 6.19). Subduction zones are where subduction takes place. As you would expect, where plates collide there are lots of intense earthquakes and volcanic eruptions. The subducting oceanic plate melts as it reenters the mantle. The magma rises and erupts. This creates a volcanic mountain range near the coast of the continent. This range is called a volcanic arc. The Andes Mountains, along the western edge of South America, are a volcanic arc (Figure 6.20). "
this scientist introduced the idea of continental drift.,(A) Hutton (B) Wegener (C) Galileo (D) Vernes,B,"Wegener had many thoughts regarding what could be the driving force behind continental drift. Another of We- geners colleagues, Arthur Holmes, elaborated on Wegeners idea that there is thermal convection in the mantle. In a convection cell, material deep beneath the surface is heated so that its density is lowered and it rises. Near the surface it becomes cooler and denser, so it sinks. Holmes thought this could be like a conveyor belt. Where two adjacent convection cells rise to the surface, a continent could break apart with pieces moving in opposite directions. Although this sounds like a great idea, there was no real evidence for it, either. Alfred Wegener died in 1930 on an expedition on the Greenland icecap. For the most part the continental drift idea was put to rest for a few decades, until technological advances presented even more evidence that the continents moved and gave scientists the tools to develop a mechanism for Wegeners drifting continents. Since youre on a virtual field trip, you get to go along with them as well. Click image to the left or use the URL below. URL: "
which of these statements supports continental drift?,(A) Identical fossils found on different continents (B) Continents that fit together like puzzle pieces (C) Identical rocks found on different continents (D) All of the above,D,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
scientists in the early 20th century thought that land bridges allowed land animals to travel between africa and south america.,(A) True (B) False,A,"Alfred Wegener, born in 1880, was a meteorologist and explorer. In 1911, Wegener found a scientific paper that listed identical plant and animal fossils on opposite sides of the Atlantic Ocean. Intrigued, he then searched for and found other cases of identical fossils on opposite sides of oceans. The explanation put out by the scientists of the day was that land bridges had once stretched between these continents. Instead, Wegener pondered the way Africa and South America appeared to fit together like puzzle pieces. Other scientists had suggested that Africa and South America had once been joined, but Wegener was the ideas most dogged supporter. Wegener amassed a tremendous amount of evidence to support his hypothesis that the continents had once been joined. Imagine that youre Wegeners colleague. What sort of evidence would you look for to see if the continents had actually been joined and had moved apart? "
fossils of the seed fern glossopteris were easily carried by wind across oceans.,(A) True (B) False,B,"Wegener also found evidence for continental drift from fossils (Figure 6.7). The same type of plant and animal fossils are found on continents that are now widely separated. These organisms would not have been able to travel across the oceans. Fossils of the seed fern Glossopteris are found across all of the southern continents. These seeds are too heavy to be carried across the ocean by wind. Mesosaurus fossils are found in South America and South Africa. Mesosaurus could swim, but only in fresh water. Cynognathus and Lystrosaurus were reptiles that lived on land. Both of these animals were unable to swim at all. Their fossils have been found across South America, Africa, India and Antarctica. Wegener thought that all of these organisms lived side by side. The lands later moved apart so that the fossils are separated. "
continental drift is the idea that move around on earths surface.,(A) True (B) False,A,"Seafloor spreading is the mechanism for Wegeners drifting continents. Convection currents within the mantle take the continents on a conveyor-belt ride of oceanic crust that, over millions of years, takes them around the planets surface. The spreading plate takes along any continent that rides on it. Click image to the left or use the URL below. URL: "
the mountain ranges in the appalachians are similar to mountain ranges in,(A) Eastern Europe (B) Eastern Greenland (C) The Himalayas (D) Australia,B,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
which of these is not evidence of continental drift?,(A) Rock deposits left by ancient glaciers (B) Mountain ranges that formed together (C) Coral reefs drifted to locations where they could not grow now (D) Glaciers formed in tropical regions in the distant past,D,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
coal found on land that is now in a cold climate indicates that,(A) Coal formed under different conditions in the past (B) Coal can form under many conditions (C) The land the coal is on has moved (D) The land the coal is on is hotter than most continents,C,"By knowing something about the climate a type of organism lives in now, geologists can use fossils to decipher the climate at the time the fossil was deposited. For example, coal beds form in tropical environments but ancient coal beds are found in Antarctica. Geologists know that at that time the climate on the Antarctic continent was much warmer. Recall from the chapter Plate Tectonics that Wegener used the presence of coal beds in Antarctica as one of the lines of evidence for continental drift. "
the reason the hypothesis that mountains cooled in that form from molten material is good is that mountains are the same age.,(A) True (B) False,B,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
the coriolis effect describes how,(A) Earth’s rotation steers the movement of air and water (B) Earth’s rotation goes in different directions in the northern and southern hemisphere (C) How Earth moves beneath and water (D) causing it to appear that their motion is curved (E) d All of the above,C,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
"if a pilot wants to fly to a city that is 1000 miles due north of his starting city, he must fly",(A) Due north (B) North but also east (C) North but also west (D) Due west,B,"Look again at the map in the Figure 1.1. The distance from Jordans house to the post office is 3 km. But if Jordan told a friend how to reach the post office from his house, he couldnt just say go 3 kilometers. The friend might end up at the park instead of the post office. Jordan would have to include direction as well as distance. He could say, go west for 2 kilometers and then go north for 1 kilometer. "
coriolis effect occurs because earth is rotating beneath a moving object.,(A) True (B) False,A,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
freely moving objects appear to move to the right in the southern hemisphere.,(A) True (B) False,B,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
you can tell which hemisphere youre in because water in a drain always spirals right in the northern hemisphere and left in the southern hemisphere.,(A) True (B) False,B,"When a surface current collides with land, the current must change direction. In the Figure 1.1, the Atlantic South Equatorial Current travels westward along the Equator until it reaches South America. At Brazil, some of it goes north and some goes south. Because of Coriolis effect, the water goes right in the Northern Hemisphere and left in the Southern Hemisphere. "
"coriolis is an effect, because it is not forcing the movement of objects to change, it just appears that the movement of objects is not straight.",(A) True (B) False,A,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
in which direction will an ocean current that is traveling south from the north pole curve due to coriolis effect?,(A) North (B) South (C) East (D) West,D,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
in which direction will an ocean current that is traveling north from the south pole curve due to coriolis effect?,(A) North (B) South (C) East (D) West,D,"The Coriolis effect describes how Earths rotation steers winds and surface ocean currents (Figure 1.1). Coriolis causes freely moving objects to appear to move to the right in the Northern Hemisphere and to the left in the Southern Hemisphere. The objects themselves are actually moving straight, but the Earth is rotating beneath them, so they seem to bend or curve. Thats why it is incorrect to call Coriolis a force. It is not forcing anything to happen! An example might make the Coriolis effect easier to visualize. If an airplane flies 500 miles due north, it will not arrive at the city that was due north of it when it began its journey. Over the time it takes for the airplane to fly 500 miles, that city moved, along with the Earth it sits on. The airplane will therefore arrive at a city to the west of the original city (in the Northern Hemisphere), unless the pilot has compensated for the change. So to reach his intended destination, the pilot must also veer right while flying north. As wind or an ocean current moves, the Earth spins underneath it. As a result, an object moving north or south along the Earth will appear to move in a curve instead of in a straight line. Wind or water that travels toward the poles from the Equator is deflected to the east, while wind or water that travels toward the Equator from the poles gets bent to the west. The Coriolis effect bends the direction of surface currents to the right in the Northern Hemisphere and left in the Southern Hemisphere. The Coriolis effect causes winds and cur- rents to form circular patterns. The di- rection that they spin depends on the hemisphere that they are in. Coriolis effect is demonstrated using a metal ball and a rotating plate in this video. The ball moves in a circular path just like a freely moving particle of gas or liquid moves on the rotating Earth (5b). Click image to the left or use the URL below. URL: "
in which direction will an airplane need to travel if it is flying from 45on 120ow (near the pacific ocean) to 45on 90ow (near the great lakes)?,(A) East (B) but curving to the right (C) b East (D) but curving to the left (E) c Due east (F) d Due west,C,"In a normal year, the trade winds blow across the Pacific Ocean near the Equator from east to west (toward Asia). A low pressure cell rises above the western equatorial Pacific. Warm water in the western Pacific Ocean raises sea levels by half a meter. Along the western coast of South America, the Peru Current carries cold water northward, and then westward along the Equator with the trade winds. Upwelling brings cold, nutrient-rich waters from the deep sea. "
an ocean current traveling across the north pacific ocean from west to east runs into north america. which direction does it go from there?,(A) It turns right (B) If turns left (C) It goes straight (D) It goes back the way it came,A,"When a surface current collides with land, the current must change direction. In the Figure 1.1, the Atlantic South Equatorial Current travels westward along the Equator until it reaches South America. At Brazil, some of it goes north and some goes south. Because of Coriolis effect, the water goes right in the Northern Hemisphere and left in the Southern Hemisphere. "
a thin rock unit with a high concentration of a very rare element in it found all over the globe could be the same unit.,(A) True (B) False,A,"Native elements contain atoms of only one type of element. Only a small number of minerals are found in this category. Some of the minerals in this group are rare and valuable. Gold (Figure 1.3), silver, sulfur, and diamond are examples of native elements. "
an index fossil should,(A) Be widespread (B) Have existed for only a brief period of time (C) Be identifiable (D) All of the above,D,"An index fossil can be used to identify a specific period of time. Organisms that make good index fossils are distinctive, widespread, and lived briefly. Their presence in a rock layer can be used to identify rocks that were deposited at that period of time over a large area. "
"to determine that similar rock layers spread over a large area are actually the same rock unit, try to identify",(A) An index fossil (B) The rock type (C) The rock’s relative age (D) How the rock formed,A,Index fossils are commonly used to match rock layers in different places. You can see how this works in Figure 
the only useful index fossils are shells and skeletons of marine organisms.,(A) True (B) False,B,"Usually its only the hard parts that are fossilized. The fossil record consists almost entirely of the shells, bones, or other hard parts of animals. Mammal teeth are much more resistant than other bones, so a large portion of the mammal fossil record consists of teeth. The shells of marine creatures are common also. "
a key bed must,(A) Contain one or more index fossils (B) Be very distinctive (C) Must be found only in a limited area (D) All of these,B,"3. A key bed can be used like an index fossil since a key bed is a distinctive layer of rock that can be recognized across a large area. A volcanic ash unit could be a good key bed. One famous key bed is the clay layer at the boundary between the Cretaceous Period and the Tertiary Period, the time that the dinosaurs went extinct (Figure in asteroids. In 1980, the father-son team of Luis and Walter Alvarez proposed that a huge asteroid struck Earth 66 million years ago and caused the mass extinction. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
which of the following is good for correlation?,(A) A volcanic ash because it may be spread around the globe (B) A microfossil that can be spread over the ocean surface and then in the seafloor sediments (C) A distinctive fossil assemblage (D) All of these,D,Superposition and cross-cutting are helpful when rocks are touching one another and lateral continuity helps match up rock layers that are nearby. To match up rocks that are further apart we need the process of correlation. How do geologists correlate rock layers that are separated by greater distances? There are three kinds of clues: 
a good example of a key bed is the thin clay with high iridium that indicates that a huge asteroid struck earth 66 million years ago.,(A) True (B) False,A,"Like index fossils, key beds are used to match rock layers. A key bed is a thin layer of rock. The rock must be unique and widespread. For example, a key bed from around the time that the dinosaurs went extinct is very important. A thin layer of clay was deposited over much of Earths surface. The clay has large amount of the element iridium. Iridium is rare on Earth but common in asteroids. This unusual clay layer has been used to match rock up layers all over the world. It also led to the hypothesis that a giant asteroid struck Earth and caused the dinosaurs to go extinct. "
the thin clay with a high concentration of iridium correlates with,(A) The extinction of 95% of all Earth’s life at the end of the Permian (B) A massive volcanic eruption that was triggered by the asteroid impact (C) The extinction of the dinosaurs and other organisms at the end of the Cretaceous (D) The beginning of life on Earth (E) which was triggered by the asteroid impact,C,"Like index fossils, key beds are used to match rock layers. A key bed is a thin layer of rock. The rock must be unique and widespread. For example, a key bed from around the time that the dinosaurs went extinct is very important. A thin layer of clay was deposited over much of Earths surface. The clay has large amount of the element iridium. Iridium is rare on Earth but common in asteroids. This unusual clay layer has been used to match rock up layers all over the world. It also led to the hypothesis that a giant asteroid struck Earth and caused the dinosaurs to go extinct. "
deep ocean circulation is driven by differences in,(A) Density & mass (B) Pressure & temperature (C) Temperature & salinity (D) None of the above,C,"Thermohaline circulation drives deep ocean circulation. Thermo means heat and haline refers to salinity. Dif- ferences in temperature and in salinity change the density of seawater. So thermohaline circulation is the result of density differences in water masses because of their different temperature and salinity. What is the temperature and salinity of very dense water? Lower temperature and higher salinity yield the densest water. When a volume of water is cooled, the molecules move less vigorously, so same number of molecules takes up less space and the water is denser. If salt is added to a volume of water, there are more molecules in the same volume, so the water is denser. "
water is denser when salt is added.,(A) True (B) False,A,"With so many dissolved substances mixed in seawater, what is the density (mass per volume) of seawater relative to fresh water? Water density increases as: salinity increases temperature decreases pressure increases Differences in water density are responsible for deep ocean currents, as will be discussed in the ""Deep Ocean Currents"" concept. Click image to the left or use the URL below. URL: "
"what helps to bring cool, nutrient-rich water to the surface?",(A) Downwelling (B) Upwelling (C) Evaporation (D) Swelling,B,"Sometimes deep ocean water rises to the surface. This is called upwelling. Figure 14.18 shows why it happens. Strong winds blow surface water away from shore. This allows deeper water to flow to the surface and take its place. When water comes up from the deep, it brings a lot of nutrients with it. Why is deep water so full of nutrients? Over time, dead organisms and other organic matter settle to the bottom water and collect. The nutrient-rich water that comes to the surface by upwelling supports many living things. "
this makes surface water sink.,(A) Heating or evaporation of fresh water (B) Heating and cooling (C) Cooling or evaporation of fresh water (D) Evaporation of fresh water and nutrients,C,Lowering the water table may cause the ground surface to sink. Subsidence may occur beneath houses and other structures (Figure 1.4). 
downwelling takes place at some coastlines or along the equators and brings nutrient-rich water to the surface.,(A) True (B) False,B,"Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling (Figure 1.2). Upwelling forces denser water from below to take the place of less dense water at the surface that is pushed away by the wind. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column. Upwelling brings those nutrients to the surface. Those nutrients support the growth of plankton and form the base of a rich ecosystem. California, South America, South Africa, and the Arabian Sea all benefit from offshore upwelling. Upwelling also takes place along the Equator between the North and South Equatorial Currents. Winds blow the surface water north and south of the Equator, so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Click image to the left or use the URL below. URL: "
"along the coast of south america, a tremendous ecosystem grows due to __________ along the coast.",(A) Upwelling (B) Downwelling (C) Longshore currents (D) Rip currents,A,"Since unlimited amounts of water cannot sink to the bottom of the ocean, water must rise from the deep ocean to the surface somewhere. This process is called upwelling (Figure 1.2). Upwelling forces denser water from below to take the place of less dense water at the surface that is pushed away by the wind. Generally, upwelling occurs along the coast when wind blows water strongly away from the shore. This leaves a void that is filled by deep water that rises to the surface. Upwelling is extremely important where it occurs. During its time on the bottom, the cold deep water has collected nutrients that have fallen down through the water column. Upwelling brings those nutrients to the surface. Those nutrients support the growth of plankton and form the base of a rich ecosystem. California, South America, South Africa, and the Arabian Sea all benefit from offshore upwelling. Upwelling also takes place along the Equator between the North and South Equatorial Currents. Winds blow the surface water north and south of the Equator, so deep water undergoes upwelling. The nutrients rise to the surface and support a great deal of life in the equatorial oceans. Click image to the left or use the URL below. URL: "
how does the salinity of water in an ocean increase?,(A) Fresh water evaporates (B) Fresh water freezes into sea ice (C) Salt is added (D) A & B,D,"Changes in temperature and salinity of seawater take place at the surface. Water becomes dense near the poles. Cold polar air cools the water and lowers its temperature, increasing its salinity. Fresh water freezes out of seawater to become sea ice, which also increases the salinity of the remaining water. This very cold, very saline water is very dense and sinks. This sinking is called downwelling. This video lecture discusses the vertical distribution of life in the oceans. Seawater density creates currents, which provide different habitats for different creatures: Click image to the left or use the URL below. URL:  Two things then happen. The dense water pushes deeper water out of its way and that water moves along the bottom of the ocean. This deep water mixes with less dense water as it flows. Surface currents move water into the space vacated at the surface where the dense water sank (Figure 1.1). Water also sinks into the deep ocean off of Antarctica. Cold water (blue lines) sinks in the North Atlantic, flows along the bottom of the ocean and upwells in the Pacific or Indian. The water then travels in surface currents (red lines) back to the North Atlantic. Deep water also forms off of Antarctica. "
ocean currents move through the surface and deep in a large system like a conveyor belt.,(A) True (B) False,A,"Another way ocean water moves is in currents. A current is a stream of moving water that flows through the ocean. Surface currents are caused mainly by winds, but not the winds that blow and change each day. Surface currents are caused by the major wind belts that blow in the same direction all the time. The major surface currents are shown in Figure 14.15. They flow in a clockwise direction in the Northern Hemi- sphere. In the Southern Hemisphere, they flow in the opposite direction. "
the relative age of a rock is,(A) The age of the rock in years (B) The age of the rock relative to other rocks and geologic structures (C) The age of the rock as determined by radiometric dating (D) All of these,B,"Early geologists had no way to determine the absolute age of a geological material. If they didnt see it form, they couldnt know if a rock was one hundred years or 100 million years old. What they could do was determine the ages of materials relative to each other. Using sensible principles they could say whether one rock was older than another and when a process occurred relative to those rocks. "
the _________ rock unit lies beneath the __________ rock units above it.,(A) Sedimentary; igneous (B) Igneous; sedimentary (C) Older; younger (D) Younger; older,C,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
if a fault cuts a rock sequence that fault is,(A) Younger than the rock sequence (B) Older than the rock sequence (C) The same age as the rock sequence (D) Of an unknown age relative to the rock sequence,A,"If the blocks of rock on one or both sides of a fracture move, the fracture is called a fault (Figure 1.2). Stresses along faults cause rocks to break and move suddenly. The energy released is an earthquake. How do you know theres a fault in this rock? Try to line up the same type of rock on either side of the lines that cut across them. One side moved relative to the other side, so you know the lines are a fault. Slip is the distance rocks move along a fault. Slip can be up or down the fault plane. Slip is relative, because there is usually no way to know whether both sides moved or only one. Faults lie at an angle to the horizontal surface of the Earth. That angle is called the faults dip. The dip defines which of two basic types a fault is. If the faults dip is inclined relative to the horizontal, the fault is a dip-slip fault (Figure 1.3). "
older rocks lie above the younger rocks.,(A) True (B) False,B,"Superposition refers to the position of rock layers and their relative ages. Relative age means age in comparison with other rocks, either younger or older. The relative ages of rocks are important for understanding Earths history. New rock layers are always deposited on top of existing rock layers. Therefore, deeper layers must be older than layers closer to the surface. This is the law of superposition. You can see an example in Figure 11.7. "
"in the geologic cross section in the concept, intrusion d cuts across rock layers c and b. rock layer b and intrusion d are offset by fault e. what are the relative ages of these features from older to younger?",(A) Fault E (B) intrusion D (C) rock layer B (D) rock layer C (E) b Rock layer C (F) rock layer B (G) fault E (H) intrusion D (I) c Intrusion D (J) fault E (K) rock layer B (L) rock layer C (M) d Rock layer C (N) rock layer B (O) intrusion D (P) fault E,D,"Stenos and Smiths principles are essential for determining the relative ages of rocks and rock layers. In the process of relative dating, scientists do not determine the exact age of a fossil or rock but look at a sequence of rocks to try to decipher the times that an event occurred relative to the other events represented in that sequence. The relative age of a rock then is its age in comparison with other rocks. If you know the relative ages of two rock layers, (1) Do you know which is older and which is younger? (2) Do you know how old the layers are in years? In some cases, it is very tricky to determine the sequence of events that leads to a certain formation. Can you figure out what happened in what order in (Figure 1.1)? Write it down and then check the following paragraphs. The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D). So the fault must be the youngest feature. The intrusion (D) cuts through the three sedimentary rock layers, so it must be younger than those layers. By the law of superposition, C is the oldest sedimentary rock, B is younger and A is still younger. The full sequence of events is: 1. Layer C formed. 2. Layer B formed. A geologic cross section: Sedimentary rocks (A-C), igneous intrusion (D), fault (E). 3. Layer A formed. 4. After layers A-B-C were present, intrusion D cut across all three. 5. Fault E formed, shifting rocks A through C and intrusion D. 6. Weathering and erosion created a layer of soil on top of layer A. Click image to the left or use the URL below. URL: "
a fault can cut through three or more sedimentary rock layers.,(A) True (B) False,A,"Stenos and Smiths principles are essential for determining the relative ages of rocks and rock layers. In the process of relative dating, scientists do not determine the exact age of a fossil or rock but look at a sequence of rocks to try to decipher the times that an event occurred relative to the other events represented in that sequence. The relative age of a rock then is its age in comparison with other rocks. If you know the relative ages of two rock layers, (1) Do you know which is older and which is younger? (2) Do you know how old the layers are in years? In some cases, it is very tricky to determine the sequence of events that leads to a certain formation. Can you figure out what happened in what order in (Figure 1.1)? Write it down and then check the following paragraphs. The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D). So the fault must be the youngest feature. The intrusion (D) cuts through the three sedimentary rock layers, so it must be younger than those layers. By the law of superposition, C is the oldest sedimentary rock, B is younger and A is still younger. The full sequence of events is: 1. Layer C formed. 2. Layer B formed. A geologic cross section: Sedimentary rocks (A-C), igneous intrusion (D), fault (E). 3. Layer A formed. 4. After layers A-B-C were present, intrusion D cut across all three. 5. Fault E formed, shifting rocks A through C and intrusion D. 6. Weathering and erosion created a layer of soil on top of layer A. Click image to the left or use the URL below. URL: "
"in the geologic cross section in the concept, the last thing to happen in the sequence was",(A) The laying down of sedimentary rock layer C (B) The igneous intrusion D (C) The fault E (D) The erosion of the surface,D,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
a fault offsets three older sedimentary rock layers. this displays the principle of,(A) Horizontality (B) Cross-cutting relationships (C) Lateral continuity (D) Faunal succession,B,"Stenos and Smiths principles are essential for determining the relative ages of rocks and rock layers. In the process of relative dating, scientists do not determine the exact age of a fossil or rock but look at a sequence of rocks to try to decipher the times that an event occurred relative to the other events represented in that sequence. The relative age of a rock then is its age in comparison with other rocks. If you know the relative ages of two rock layers, (1) Do you know which is older and which is younger? (2) Do you know how old the layers are in years? In some cases, it is very tricky to determine the sequence of events that leads to a certain formation. Can you figure out what happened in what order in (Figure 1.1)? Write it down and then check the following paragraphs. The principle of cross-cutting relationships states that a fault or intrusion is younger than the rocks that it cuts through. The fault cuts through all three sedimentary rock layers (A, B, and C) and also the intrusion (D). So the fault must be the youngest feature. The intrusion (D) cuts through the three sedimentary rock layers, so it must be younger than those layers. By the law of superposition, C is the oldest sedimentary rock, B is younger and A is still younger. The full sequence of events is: 1. Layer C formed. 2. Layer B formed. A geologic cross section: Sedimentary rocks (A-C), igneous intrusion (D), fault (E). 3. Layer A formed. 4. After layers A-B-C were present, intrusion D cut across all three. 5. Fault E formed, shifting rocks A through C and intrusion D. 6. Weathering and erosion created a layer of soil on top of layer A. Click image to the left or use the URL below. URL: "
a fault can shift rocks so that the layers no longer match up.,(A) True (B) False,A,"With enough stress, a rock will fracture, or break. The fracture is called a joint if the rock breaks but doesnt move, as shown in Figure 7.10. If the rocks on one or both sides of a fracture move, the fracture is called a fault (Figure 7.11). Faults can occur alone or in clusters, creating a fault zone. Earthquakes happen when rocks break and move suddenly. The energy released causes an earthquake. Slip is the distance rocks move along a fault, as one block of rock moves past the other. The angle of a fault is called When compression squeezes the crust into a smaller space, the hanging wall pushes up relative to the footwall. This creates a reverse fault. A thrust fault is a type of reverse fault where the angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 7.13). "
"if we learn the succession of geological events in a region, it only tells us about that region and does not apply to other locations.",(A) True (B) False Sources Figure 1: CK-12: http://wwwck12org/earth-science/Determining-Relative- Ages/lesson/Determining-Relative-Ages/,B,"First, lets review plate tectonics theory. Plate tectonics theory explains why: Earths geography has changed over time and continues to change today. some places are prone to earthquakes while others are not. certain regions may have deadly, mild, or no volcanic eruptions. mountain ranges are located where they are. many ore deposits are located where they are. living and fossil species are found where they are. Plate tectonic motions affect Earths rock cycle, climate, and the evolution of life. "
the law of conservation of energy says that energy cannot be created or destroyed.,(A) True (B) False,A,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
which one of these is an example of chemical energy?,(A) A match lighting a candle (B) Kicking a ball (C) Going down a slide (D) Pedaling a bicycle,A,"If you think about different sources of energysuch as batteries and the sunyou probably realize that energy can take different forms. For example, when the boy swings his tennis racket, the energy of the moving racket is an example of mechanical energy. To move his racket, the boy needs energy stored in food, which is an example of chemical energy. Other forms of energy include electrical, thermal, light, and sound energy. The different forms of energy can also be classified as either kinetic energy or potential energy. Kinetic energy is the energy of moving matter. Potential energy is energy that is stored in matter. Q: Is the chemical energy in food kinetic energy or potential energy? A: The chemical energy in food is potential energy. It is stored in the chemical bonds that make up food molecules. The stored energy is released when we digest food. Then we can use it for many purposes, such as moving (mechanical energy) or staying warm (thermal energy). Q: What is an example of kinetic energy? A: Anything that is moving has kinetic energy. An example is a moving tennis racket. "
which one of these is not an example of potential energy?,(A) A ball sitting at the top of a hill (B) A batter ready to hit a ball (C) The kick of a leg on a soccer ball (D) An apple hanging from a tree,C,"All of the examples of potential energy described above involve movement or the potential to move. The form of energy that involves movement is called mechanical energy. Other forms of energy also involve potential energy, including chemical energy and nuclear energy. Chemical energy is stored in the bonds between the atoms of compounds. For example, food and batteries both contain chemical energy. Nuclear energy is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. Nuclei of radioactive elements such as uranium are unstable, so they break apart and release the stored energy. "
burning fuel is an example of using this kind of energy.,(A) Potential Energy (B) Kinetic Energy (C) Electrical Energy (D) Chemical Energy,D,"The energy to make the electricity comes from fuel. Fuel stores the energy and releases it when it is needed. Fuel is any material that can release energy in a chemical change. The food you eat acts as a fuel for your body. Gasoline and diesel fuel are fuels that provide the energy for most cars, trucks, and buses. But there are many different kinds of fuel. For fuel to be useful, its energy must be released in a way that can be controlled. "
kinetic energy is energy associated with the movement of atoms or molecules that can be transferred.,(A) True (B) False,B,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
which of these is an example of chemical energy?,(A) Food is fuel for the body (B) Sunlight to make energy for plants during photosynthesis (C) Gasoline as fuel for cars (D) All of the above,D,"If you think about different sources of energysuch as batteries and the sunyou probably realize that energy can take different forms. For example, when the boy swings his tennis racket, the energy of the moving racket is an example of mechanical energy. To move his racket, the boy needs energy stored in food, which is an example of chemical energy. Other forms of energy include electrical, thermal, light, and sound energy. The different forms of energy can also be classified as either kinetic energy or potential energy. Kinetic energy is the energy of moving matter. Potential energy is energy that is stored in matter. Q: Is the chemical energy in food kinetic energy or potential energy? A: The chemical energy in food is potential energy. It is stored in the chemical bonds that make up food molecules. The stored energy is released when we digest food. Then we can use it for many purposes, such as moving (mechanical energy) or staying warm (thermal energy). Q: What is an example of kinetic energy? A: Anything that is moving has kinetic energy. An example is a moving tennis racket. "
where does energy come from?,(A) Fuel (B) Heat (C) Photosynthesis (D) Gasoline,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
animals and plants get energy directly or indirectly from the sun.,(A) True (B) False,A,"Living things can be classified based on how they obtain energy. Some use the energy in sunlight or chemical compounds directly to make food. Some get energy indirectly by consuming other organisms, either living or dead. "
"if a person eats a sandwich in a park on top of a hill, stands on their bike at the top of the hill, and then rides the bike down, the energy conversions are",(A) Kinetic to potential to chemical (B) Chemical to potential to kinetic (C) Chemical to kinetic to potential (D) Potential to kinetic to chemical,B,"The law of conservation of energy applies to energy conversions. Energy is not used up when it changes form, although some energy may be used to overcome friction, and this energy is usually given off as heat. For example, the divers kinetic energy at the bottom of his fall is the same as his potential energy when he was on the diving board, except for a small amount of heat resulting from friction with the air as he falls. "
parallax is used to measure the distance of,(A) All stars (B) Stars that are anywhere in the Milky Way Galaxy (C) Stars that are only a few light years from us (D) Stars that are no more than a few hundred light years from us,D,"Distances to stars that are relatively close to us can be measured using parallax. Parallax is an apparent shift in position that takes place when the position of the observer changes. To see an example of parallax, try holding your finger about 1 foot (30 cm) in front of your eyes. Now, while focusing on your finger, close one eye and then the other. Alternate back and forth between eyes, and pay attention to how your finger appears to move. The shift in position of your finger is an example of parallax. Now try moving your finger closer to your eyes, and repeat the experiment. Do you notice any difference? The closer your finger is to your eyes, the greater the position changes because of parallax. As Figure 1.1 shows, astronomers use this same principle to measure the distance to stars. Instead of a finger, they focus on a star, and instead of switching back and forth between eyes, they switch between the biggest possible differences in observing position. To do this, an astronomer first looks at the star from one position and notes where the star is relative to more distant stars. Now where will the astronomer go to make an observation the greatest possible distance from the first observation? In six months, after Earth moves from one side of its orbit around the Sun to the other side, the astronomer looks at the star again. This time parallax causes the star to appear in a different position relative to more distant stars. From the size of this shift, astronomers can calculate the distance to the star. "
"to test parallax, put your finger about one foot in front of your eyes and then look at it from one eye and then the other.",(A) True (B) False,A,"Distances to stars that are relatively close to us can be measured using parallax. Parallax is an apparent shift in position that takes place when the position of the observer changes. To see an example of parallax, try holding your finger about 1 foot (30 cm) in front of your eyes. Now, while focusing on your finger, close one eye and then the other. Alternate back and forth between eyes, and pay attention to how your finger appears to move. The shift in position of your finger is an example of parallax. Now try moving your finger closer to your eyes, and repeat the experiment. Do you notice any difference? The closer your finger is to your eyes, the greater the position changes because of parallax. As Figure 1.1 shows, astronomers use this same principle to measure the distance to stars. Instead of a finger, they focus on a star, and instead of switching back and forth between eyes, they switch between the biggest possible differences in observing position. To do this, an astronomer first looks at the star from one position and notes where the star is relative to more distant stars. Now where will the astronomer go to make an observation the greatest possible distance from the first observation? In six months, after Earth moves from one side of its orbit around the Sun to the other side, the astronomer looks at the star again. This time parallax causes the star to appear in a different position relative to more distant stars. From the size of this shift, astronomers can calculate the distance to the star. "
"to use parallax to determine the distance to a star, astronomers must observe that star",(A) Relative to more distant stars at two opposite sides of Earth’s orbit (B) Relative to more distant stars at two times of day (C) 12 hours apart (D) c Relative to the sun (E) at two different times (F) 6 months apart (G) d Relative to the Sun (H) at two different times of day (I) 12 hours apart,A,"Distances to stars that are relatively close to us can be measured using parallax. Parallax is an apparent shift in position that takes place when the position of the observer changes. To see an example of parallax, try holding your finger about 1 foot (30 cm) in front of your eyes. Now, while focusing on your finger, close one eye and then the other. Alternate back and forth between eyes, and pay attention to how your finger appears to move. The shift in position of your finger is an example of parallax. Now try moving your finger closer to your eyes, and repeat the experiment. Do you notice any difference? The closer your finger is to your eyes, the greater the position changes because of parallax. As Figure 1.1 shows, astronomers use this same principle to measure the distance to stars. Instead of a finger, they focus on a star, and instead of switching back and forth between eyes, they switch between the biggest possible differences in observing position. To do this, an astronomer first looks at the star from one position and notes where the star is relative to more distant stars. Now where will the astronomer go to make an observation the greatest possible distance from the first observation? In six months, after Earth moves from one side of its orbit around the Sun to the other side, the astronomer looks at the star again. This time parallax causes the star to appear in a different position relative to more distant stars. From the size of this shift, astronomers can calculate the distance to the star. "
"when observing stars, this is the furthest apart two locations on the earths orbit can be.",(A) 1 au (B) 2 au (C) 3 au (D) 4 au,B,"Although the stars in a constellation appear close together as we see them in our night sky, they are not at all close together out in space. In the constellation Orion, the stars visible to the naked eye are at distances ranging from just 26 light-years (which is relatively close to Earth) to several thousand light-years away. Click image to the left or use the URL below. URL: "
"even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away.",(A) True (B) False,A,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
"the more distant the star, the more accurate our estimate of its distance.",(A) True (B) False,B,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
"to determine the properties of a distance star, astronomers compare that star to",(A) The nearest star to our solar system (B) Alpha Centauri (C) b Betelgeuse in the constellation Orion (D) c The Sun (E) d Jupiter,C,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
au stands for __________ and it is the distance between __________.,(A) Astrology units; Earth and the nearest star (B) Astronomical units; Earth and the Sun (C) Astrology units; Earth and the Sun (D) Astronomical units; Earth and the nearest star,B,"Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km, or 93 million miles. Table 1.2 shows the distances to the planets (the average radius of orbits) in AU. The table also shows how long it takes each planet to spin on its axis (the length of a day) and how long it takes each planet to complete an orbit (the length of a year); in particular, notice how slowly Venus rotates relative to Earth. Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year (In Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 Click image to the left or use the URL below. URL: "
"to determine the distance of a star that is far away, astronomers",(A) Compare observed size to expected size (B) Determine its color (C) Use parallax with more precise instruments (D) Compare observed brightness to expected brightness,D,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
earth is known as the water planet. the oceans contain this much of the planets water.,(A) 67% (B) 87% (C) 97% (D) 107%,C,"Earth is often called the water planet. Figure 13.1 shows why. If astronauts see Earth from space, this is how it looks. Notice how blue the planet appears. Thats because oceans cover much of Earths surface. Water is also found in the clouds that rise above the planet. Most of Earths water is salt water in the oceans. As Figure 13.2 shows, only 3 percent of Earths water is fresh. Freshwater is water that contains little or no dissolved salt. Most freshwater is frozen in ice caps and glaciers. Glaciers cover the peaks of some tall mountains. For example, the Cascades Mountains in North America and the Alps Mountains in Europe are capped with ice. Ice caps cover vast areas of Antarctica and Greenland. Chunks of ice frequently break off ice caps. They form icebergs that float in the oceans. "
most of the earths fresh water supply is found where?,(A) Oceans (B) Glaciers (C) Lakes (D) Underground,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
which of these can be a reservoir for water?,(A) Ocean (B) Atmosphere (C) Puddle (D) All of the above,D,"Earths oceans contain 97% of the planets water. That leaves just 3% as fresh water, water with low concentrations of salts (Figure 1.1). Most fresh water is trapped as ice in the vast glaciers and ice sheets of Greenland and Antarctica. How is the 3% of fresh water divided into different reservoirs? How much of that water is useful for living creatures? How much for people? A storage location for water such as an ocean, glacier, pond, or even the atmosphere is known as a reservoir. A water molecule may pass through a reservoir very quickly or may remain for much longer. The amount of time a molecule stays in a reservoir is known as its residence time. The distribution of Earths water. Click image to the left or use the URL below. URL: "
the amount of time a molecule stays in a reservoir.,(A) Water time (B) Residence time (C) Residence resource (D) Reservoir resource,B,"The chemical elements and water that are needed by living things keep recycling on Earth. They pass back and forth through biotic and abiotic components of ecosystems. Thats why their cycles are called biogeochemical cycles. For example, a chemical element or water might move from organisms (bio) to the atmosphere or ocean (geo) and back to organisms again. Elements or water may be held for various periods of time in different parts of a biogeochemical cycle. An exchange pool is part of a cycle that holds a substance for a short period of time. For example, the atmosphere is an exchange pool for water. It usually holds water (as water vapor) for just a few days. A reservoir is part of a cycle that holds a substance for a long period of time. For example, the ocean is a reservoir for water. It may hold water for thousands of years. The rest of this lesson describes three biogeochemical cycles: water cycle, carbon cycle, and nitrogen cycle. "
"of the 1% of earths fresh water not found underground or in ice, 39% is found here.",(A) Lakes and rivers (B) Atmosphere and soil moisture (C) Soil moisture and lakes (D) Rivers and the atmosphere,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
most fresh water trapped are found in glaciers and ice sheets in,(A) Antarctica (B) Greenland (C) Iceland (D) A & B,D,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
fresh water has no salts at all.,(A) True (B) False,B,"Fresh water contains a small amount of dissolved elements. Salt water contains a lot more dissolved elements. Water can only hold a certain amount of dissolved substances. When the water evaporates, it leaves behind a solid layer of minerals, as Figure 3.18 shows. At this time, the particles come together to form minerals. These solids sink to the bottom. The amount of mineral formed is the same as the amount dissolved in the water. Seawater is salty enough for minerals to precipitate as solids. Some lakes, such as Mono Lake in California, or Utahs Great Salt Lake, can also precipitate salts. Salt easily precipitates out of water, as does calcite, as Figure 3.19 shows. The limestone towers in the figure are made mostly of the mineral calcite. The calcite was deposited in the salty and alkaline water of Mono Lake, in California. Calcium-rich spring water enters the bottom of the lake. The water bubbles up into the alkaline lake. The "
a single water molecule may remain in a reservoir for a long or a short time.,(A) True (B) False,A,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
all of earths water supply is accessible for us to use.,(A) True (B) False,B,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
earth is unique in our solar system because it has such a large liquid water ocean.,(A) True (B) False,A,"Earth is a very diverse planet, seen in Figure 25.14. Water appears as vast oceans of liquid. Water is also seen as ice at the poles or as clouds of vapor. Earth also has large masses of land. Earths average surface temperature is 14C (57F). At this temperature, water is a liquid. The oceans and the atmosphere help keep Earths surface temperatures fairly steady. Earth is the only planet known to have life. Conditions on Earth are ideal for life! The atmosphere filters out harmful radiation. Water is abundant. Carbon dioxide was available for early life forms. The evolution of plants introduced more oxygen for animals. "
what qualities define a planet?,(A) Orbits a star (B) Is big enough to have its own gravity causing it to be shaped as a sphere (C) Has cleared the area of its orbit of smaller objects (D) All of the above,D,"In 2006, the International Astronomical Union decided that there were too many questions surrounding what could be called a planet, and so refined the definition of a planet. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be shaped as a sphere. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. "
what is not characteristic of a dwarf planet?,(A) Orbits a star (B) Is big enough to have its own gravity causing it to be shaped as a sphere (C) Has cleared the area of its orbit of smaller objects (D) All of the above,C,"The dwarf planets of our solar system are exciting proof of how much we are learning about our solar system. With the discovery of many new objects in our solar system, astronomers refined the definition of a dwarf planet in 2006. According to the IAU, a dwarf planet must: Orbit a star. Have enough mass to be nearly spherical. Not have cleared the area around its orbit of smaller objects. Not be a moon. "
pluto was thought to be one of nine planets in our solar system from 1930 to 2006.,(A) True (B) False,A,"Pluto was once considered one of the outer planets, but when the definition of a planet was changed in 2006, Pluto became one of the dwarf planets. It is one of the largest and brightest objects that make up this group. Look for Pluto in the next lesson, in the discussion of dwarf planets. "
why was pluto thought to be a planet when it was first observed through a telescope in 1930?,(A) Pluto and its moon (B) Charon (C) appeared as one much larger object (D) b Pluto was larger (E) but it has been struck by so many meteorites that it’s gotten smaller (F) c Pluto was thought to be spherical but it was found not to be (G) d Pluto was found to be a star,A,"Youve probably heard about Pluto. When it was discovered in 1930, Pluto was called the ninth planet. Astronomers later found out that Pluto was not like other planets. For one thing, what they were calling Pluto was not a single object. They were actually seeing Pluto and its moon, Charon. In older telescopes, they looked like one object. This one object looked big enough to be a planet. Alone, Pluto was not very big. Astronomers also discovered many objects like Pluto. They were rocky and icy and there were a whole lot of them. Astronomers were faced with a problem. They needed to call these other objects planets. Or they needed to decide that Pluto was something else. In 2006, these scientists decided what a planet is. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be round. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. If the first three are true but not the fourth, then that object is a dwarf planet. We now call Pluto a dwarf planet. There are other dwarf planets in the solar system. They are Eris, Ceres, Makemake and Haumea. There are many other reasons why Pluto does not fit with the other planets in our solar system. "
why is pluto no longer considered to be a planet?,(A) It is very unlike the other outer planets (B) It is smaller than one dwarf planet and Earth’s Moon (C) It is part of the Kuiper belt with 200 million other objects (D) All of the above,D,"Youve probably heard about Pluto. When it was discovered in 1930, Pluto was called the ninth planet. Astronomers later found out that Pluto was not like other planets. For one thing, what they were calling Pluto was not a single object. They were actually seeing Pluto and its moon, Charon. In older telescopes, they looked like one object. This one object looked big enough to be a planet. Alone, Pluto was not very big. Astronomers also discovered many objects like Pluto. They were rocky and icy and there were a whole lot of them. Astronomers were faced with a problem. They needed to call these other objects planets. Or they needed to decide that Pluto was something else. In 2006, these scientists decided what a planet is. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be round. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. If the first three are true but not the fourth, then that object is a dwarf planet. We now call Pluto a dwarf planet. There are other dwarf planets in the solar system. They are Eris, Ceres, Makemake and Haumea. There are many other reasons why Pluto does not fit with the other planets in our solar system. "
"although it is in the asteroid belt, ceres is not an asteroid because it is spherical.",(A) True (B) False,A,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
ceres has been considered,(A) The 10th planet (B) The largest object in the asteroid belt (C) A dwarf planet (D) All of the above,D,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
dwarf planets are all made of,(A) Gases and ices (B) Rocks and metal (C) Methane (D) ethane and nitrogen ices (E) d None of the above,D,"Makemake is the third-largest and second-brightest dwarf planet we have discovered so far (Figure 25.39). Make- make is only 75 percent the size of Pluto. Its diameter is between 1300 and 1900 kilometers. The name comes from the mythology of the Eastern Islanders. Makemake was the god that created humanity. At a distance between 38.5 to 53 AU, this dwarf planet orbits the Sun in 310 years. Makemake is made of methane, ethane, and nitrogen ices. "
which is the largest known dwarf planet in the solar system?,(A) Ceres (B) Pluto (C) Eris (D) Makemake,C,"Eris is the largest known dwarf planet in the solar system  it has about 27% more mass than Pluto (Figure 1.3). The object was not discovered until 2003 because it is about three times farther from the Sun than Pluto, and almost 100 times farther from the Sun than Earth is. For a short time Eris was considered the tenth planet in the solar system, but its discovery helped to prompt astronomers to better define planets and dwarf planets in 2006. Eris also has a small moon, Dysnomia, that orbits it once about every 16 days. Astronomers know there may be other dwarf planets in the outer reaches of the solar system. Haumea was made a dwarf planet in 2008, so the total number of dwarf planets is now five. Quaoar, Varuna, and Orcus may be added to the list of dwarf planets in the future. We still have a lot to discover and explore. Click image to the left or use the URL below. URL: "
the final totals are 8 planets and 5 dwarf planets in the solar system.,(A) True (B) False,B,"Today we know that we have eight planets, five dwarf planets, over 165 moons, and many, many asteroids and other small objects in our solar system. We also know that the Sun is not the center of the universe. But it is the center of the solar system. Figure 25.3 shows our solar system. The planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Table 25.1 gives some data on the mass and diameter of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth Mars Jupiter Saturn Uranus 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter Neptune 17.2 Earths mass "
earths first atmosphere was made of,(A) Nitrogen and oxygen (B) Hydrogen and helium (C) Greenhouse gases (D) Noble gases,B,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
gases from the early earth,(A) Were vaporized by the intense heat of the early Earth and from impacts (B) Blew off in the intense solar wind (C) Were those that were drawn into the center of the solar nebula (D) All of the above,D,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
the gas that formed the early atmosphere came entirely from earths interior.,(A) True (B) False,B,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
"in the early atmosphere, a lot of water vapor, carbon dioxide, methane, ammonia, nitrogen and other volatiles came from",(A) The Sun (B) The Moon (C) Comets and asteroids (D) Volcanic eruptions,C,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
the early atmosphere didnt have oxygen because plants had not yet evolved.,(A) True (B) False,A,"The second atmosphere, which was the first to stay with the planet, formed from volcanic outgassing and comet ices. This atmosphere had lots of water vapor, carbon dioxide, nitrogen, and methane but almost no oxygen. Why was there so little oxygen? Plants produce oxygen when they photosynthesize but life had not yet begun or had not yet developed photosynthesis. In the early atmosphere, oxygen only appeared when sunlight split water molecules into hydrogen and oxygen and the oxygen accumulated in the atmosphere. Without oxygen, life was restricted to tiny simple organisms. Why is oxygen essential for most life on Earth? 1. Oxygen is needed to make ozone, a molecule made of three oxygen ions, O3 . Ozone collects in the atmospheric ozone layer and blocks harmful ultraviolet radiation from the Sun. Without an ozone layer, life in the early Earth was almost impossible. 2. Animals need oxygen to breathe. No animals would have been able to breathe in Earths early atmosphere. "
for a long time there were only tiny simple organisms because,(A) Without oxygen there was no ozone layer (B) Without oxygen animals couldn’t evolve (C) Evolutionary processes take a long time (D) All of the above,D,For the first 4 billion years of Earth history there is only a little evidence of life. Organisms were tiny and soft and did not fossilize well. But scientists use a variety of ways to figure out what this early life was like. 
______________ in a cell that converts energy from nutrients to useable energy.,(A) Cellular respiration (B) Photosynthesis (C) Cellular replication (D) None of the above,A,"The mitochondrion (mitochondria, plural) is an organelle that makes energy available to the cell. Its like the power plant of a cell. It uses energy in glucose to make smaller molecules called ATP (adenosine triphosphate). ATP packages energy in smaller amounts that cells can use. Think about buying a bottle of water from a vending machine. The machine takes only quarters, and you have only dollar bills. The dollar bills wont work in the vending machine. Glucose is like a dollar bill. It contains too much energy for cells to use. ATP is like a quarter. It contains just the right amount of energy for use by cells. "
what do banded-iron formations represent?,(A) The formation of rocks with a lot of iron (B) The development of an anaerobic environment (C) The addition of large amounts of oxygen into the air (D) All of these,C,"What evidence do scientists have that large quantities of oxygen entered the atmosphere? The iron contained in the rocks combined with the oxygen to form reddish iron oxides. By the beginning of the Proterozoic, banded-iron formations (BIFs) were forming. Banded-iron formations display alternating bands of iron oxide and iron-poor chert that probably represent a seasonal cycle of an aerobic and an anaerobic environment. The oldest BIFs are 3.7 billion years old, but they are very common during the Great Oxygenation Event 2.4 billion years ago (Figure 1.2). By 1.8 billion years ago, the amount of BIF declined. In recent times, the iron in these formations has been mined, and that explains the location of the auto industry in the upper Midwest. "
the great oxygenation event occurred when animals became common.,(A) True (B) False,B,"When photosynthesis evolved and spread around the planet, oxygen was released in abundance. The addition of oxygen is what created Earths third atmosphere. This event, which occurred about 2.5 billion years ago, is sometimes called the oxygen catastrophe because so many organisms died. Although entire species died out and went extinct, this event is also called the Great Oxygenation Event because it was a great opportunity. The organisms that survived developed a use for oxygen through cellular respiration, the process by which cells can obtain energy from organic molecules. This opened up many opportunities for organisms to evolve to fill different niches and many new types of organisms first appeared on Earth. "
charles darwin discovered,(A) The Galapagos Islands (B) Shell beds high in the Andes Mountains (C) Mountains and Earth must be extremely old (D) All of the above,B,"Darwin also observed that each of the Galpagos Islands had its own species of finches. The finches on different islands had beaks that differed in size and shape. You can see four examples in Figure 7.4. Darwin investigated further. He found that the different beaks seemed to suit the birds for the food available on their island. For example, finch number 1 in Figure 7.4 used its large, strong beak to crack open and eat big, tough seeds. Finch number 4 had a long, pointed beak that was ideal for eating insects. This seemed reasonable, but how had it come about? "
fossils help us learn more about,(A) Earth history (B) The history and evolution of life (C) Environmental conditions in the past (D) All of the above,D,"Fossils are our best form of evidence about Earth history, including the history of life. Along with other geological evidence from rocks and structures, fossils even give us clues about past climates, the motions of plates, and other major geological events. Since the present is the key to the past, what we know about a type of organism that lives today can be applied to past environments. "
"compared with fossils in younger rocks, fossils in older rocks are",(A) More similar to modern organisms (B) All extinct (C) Less similar to modern organisms (D) Sometimes more and sometimes less similar to modern organisms,C,"That life on Earth has changed over time is well illustrated by the fossil record. Fossils in relatively young rocks resemble animals and plants that are living today. In general, fossils in older rocks are less similar to modern organisms. We would know very little about the organisms that came before us if there were no fossils. Modern technology has allowed scientists to reconstruct images and learn about the biology of extinct animals like dinosaurs! Click image to the left for more content. "
"by knowing something about the type of organism a fossil was, geologists can determine",(A) What the environment of the region was like at that time (B) What organism it evolved from (C) What organism it evolved into (D) What the environment of the region is like now,A,"By knowing something about the type of organism the fossil was, geologists can determine whether the region was terrestrial (on land) or marine (underwater) or even if the water was shallow or deep. The rock may give clues to whether the rate of sedimentation was slow or rapid. The amount of wear and fragmentation of a fossil allows scientists to learn about what happened to the region after the organism died; for example, whether it was exposed to wave action. "
finding clam shells in a rock indicates that the region was once shallow marine.,(A) True (B) False,A,The presence of marine organisms in a rock indicates that the region where the rock was deposited was once marine. Sometimes fossils of marine organisms are found on tall mountains indicating that rocks that formed on the seabed were uplifted. 
_______ can be used to identify a specific period of time.,(A) Trace fossils (B) Index fossils (C) Body fossils (D) Complete fossils,B,"An index fossil can be used to identify a specific period of time. Organisms that make good index fossils are distinctive, widespread, and lived briefly. Their presence in a rock layer can be used to identify rocks that were deposited at that period of time over a large area. "
geologists find ancient coal beds in antarctica. the one thing they can really know from this is that,(A) Antarctica moved to its current position by plate tectonics processes (B) The swamps that make coal beds existed under different circumstances in the past (C) Africa (D) South America and Antarctica were once joined into a supercontinent (E) d The climate was much warmer on that continent at the time the coal beds formed,D,"By knowing something about the climate a type of organism lives in now, geologists can use fossils to decipher the climate at the time the fossil was deposited. For example, coal beds form in tropical environments but ancient coal beds are found in Antarctica. Geologists know that at that time the climate on the Antarctic continent was much warmer. Recall from Concept Plate Tectonics that Wegener used the presence of coal beds in Antarctica as one of the lines of evidence for continental drift. "
"if a two index fossils are found 3,000 miles apart, geologists know that the two rocks they are in",(A) Formed at the same time (B) Were once together and have now drifted apart (C) Are volcanic ash (D) Formed in subsequent time periods,A,"2. Two separated rock units with the same index fossil are of very similar age. What traits do you think an index fossil should have? To become an index fossil the organism must have (1) been widespread so that it is useful for identifying rock layers over large areas and (2) existed for a relatively brief period of time so that the approximate age of the rock layer is immediately known. Many fossils may qualify as index fossils (Figure below). Ammonites, trilobites, and graptolites are often used as index fossils. Microfossils, which are fossils of microscopic organisms, are also useful index fossils. Fossils of animals that drifted in the upper layers of the ocean are particularly useful as index fossils, since they may be distributed over very large areas. A biostratigraphic unit, or biozone, is a geological rock layer that is defined by a single index fossil or a fossil assemblage. A biozone can also be used to identify rock layers across distances. The famous White Cliffs of Dover in southwest England can be matched to similar white cliffs in Denmark and Germany. "
"if a fossil shell has been worn down, geologists know that",(A) The organism lived a rough life (B) The organism died and was deposited in soft sediment rapidly (C) The shell was eroded after the animal died (D) The shell is not representative of a once-living organism,C,"By knowing something about the type of organism the fossil was, geologists can determine whether the region was terrestrial (on land) or marine (underwater) or even if the water was shallow or deep. The rock may give clues to whether the rate of sedimentation was slow or rapid. The amount of wear and fragmentation of a fossil allows scientists to learn about what happened to the region after the organism died; for example, whether it was exposed to wave action. "
"an index fossil must be distinctive, widespread and short-lived so that it can identify a specific period of time.",(A) True (B) False,A,"An index fossil can be used to identify a specific period of time. Organisms that make good index fossils are distinctive, widespread, and lived briefly. Their presence in a rock layer can be used to identify rocks that were deposited at that period of time over a large area. "
scientists calculate earths density by using the,(A) Density of the material in each layer and the volume of each layer (B) Speed of the planet’s rotation (C) Size of the tides (D) All of the above,B,"Density is a quantity that expresses how much matter is packed into a given space. The amount of matter is its mass, and the space it takes up is its volume. To calculate the density of an object, then, you would use this formula: Density = mass volume Q: The volume of the blue rectangular solid above is 150 cm3 . If it has a mass of 300 g, what is its density? A: The density of the rectangular solid is: Density = 300 g = 2 g/cm3 150 cm3 Q: Suppose you have two boxes that are the same size but one box is full of feathers and the other box is full of books. Which box has greater density? A: Both boxes have the same volume because they are the same size. However, the books have greater mass than the feathers. Therefore, the box of books has greater density. "
the core is made of,(A) Iron and nickel metal (B) Peridotite (C) Gabbro and basalt (D) None of these,A,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
the core is less dense than the surface layers.,(A) True (B) False,B,"When Earth was entirely molten, gravity drew denser elements to the center and lighter elements rose to the surface. The separation of Earth into layers based on density is known as differentiation. The densest material moved to the center to create the planets dense metallic core. Materials that are intermediate in density became part of the mantle (Figure 1.1). "
scientists believe that metallic meteorites are representative of the core.,(A) True (B) False,A,Scientists study meteorites to learn about Earths interior. Meteorites formed in the early solar system. These objects represent early solar system materials. Some meteorites are made of iron and nickel. They are thought to be very similar to Earths core (Figure 6.2). An iron meteorite is the closest thing to a sample of the core that scientists can hold in their hands! 
earths magnetic field is caused by,(A) Convection in the mantle (B) Conduction in the mantle (C) Convection in the outer core (D) Conduction in the inner core,C,Earth is surrounded by a magnetic field (Figure 1.1) that behaves as if the planet had a gigantic bar magnet inside of it. Earths magnetic field also has a north and south pole. The magnetic field arises from the convection of molten iron and nickel metals in Earths liquid outer core. 
which statement is not true about the core?,(A) It is the cause of Earth’s magnetic field (B) The inner core causes the magnetic field (C) The inner core is hotter than the outer core (D) P-waves bend as they go into the inner core,B,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
scientists know which layer of the core is liquid and which is solid because,(A) S-waves do not go through the inner core (B) P-waves do not go through the inner core (C) S-waves do not go through the outer core (D) P-waves do not go through the outer core,C,"By tracking seismic waves, scientists have learned what makes up the planets interior (Figure 1.4). P-waves slow down at the mantle core boundary, so we know the outer core is less rigid than the mantle. S-waves disappear at the mantle core boundary, so we know the outer core is liquid. "
which of these help to verify the composition of earths core?,(A) Metallic meteorites (B) Density calculations (C) The magnetic field (D) All of the above,D,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
seismic waves indicate that the inner core is a solid and the outer core is a liquid.,(A) True (B) False,A,"By tracking seismic waves, scientists have learned what makes up the planets interior (Figure 1.4). P-waves slow down at the mantle core boundary, so we know the outer core is less rigid than the mantle. S-waves disappear at the mantle core boundary, so we know the outer core is liquid. "
the core is still extremely hot due to,(A) Heat left over from Earth’s formation (B) Solar energy that travels down from the surface (C) Radioactive decay (D) None of these,C,"The core is the Suns innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer layers of the Sun. Energy from the Suns core powers most of the solar system. "
earths crust is,(A) Denser than the interior (B) More magnetic than the interior (C) Less dense than the interior (D) Less magnetic than the interior,C,"Earths outer surface is its crust, a cold, thin, brittle outer shell made of rock. The crust is very thin relative to the radius of the planet. There are two very different types of crust, each with its own distinctive physical and chemical properties, which are summarized in Table 1.1. Crust Oceanic Continental Thickness 5-12 km (3-8 mi) Avg. 35 km (22 mi) Density 3.0 g/cm3 2.7 g/cm3 Composition Mafic Felsic Rock types Basalt and gabbro All types "
earths magnetic field is a clue that earth must be made of,(A) Rock (B) Metal (C) Sediment (D) Both b and c,B,Earth is surrounded by a magnetic field (Figure 1.1) that behaves as if the planet had a gigantic bar magnet inside of it. Earths magnetic field also has a north and south pole. The magnetic field arises from the convection of molten iron and nickel metals in Earths liquid outer core. 
material that formed in the early solar system is found on earth as,(A) Oceanic crust (B) Material that comes to the surface from the mantle (C) Material that comes to the surface from the core (D) Meteorites,D,Material at a similar distances from the Sun collided together to form each of the planets. Earth grew from material in its part of space. Moons origin was completely different from Earths. 
earths internal layer with the highest density is the,(A) Oceanic crust (B) Mantle (C) Outer core (D) Inner Core,D,"When Earth was entirely molten, gravity drew denser elements to the center and lighter elements rose to the surface. The separation of Earth into layers based on density is known as differentiation. The densest material moved to the center to create the planets dense metallic core. Materials that are intermediate in density became part of the mantle (Figure 1.1). "
one of the reasons we know that earths core is metallic is,(A) The magnetic field (B) Core samples that travel through the planet to the surface (C) The attraction of solar wind to our planet (D) Moon’s gravitational attraction to Earth,A,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
"scientists learn about earths interior from seismic waves, rocks and calculations of density and magnetism.",(A) True (B) False,A,Geologists study earthquake waves to see Earths interior. Waves of energy radiate out from an earthquakes focus. These are called seismic waves (Figure 6.1). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earths interior. 
who wrote a journey to the center of the earth?,(A) Rowling (B) Alfred Wegener (C) Jules Verne (D) Stein,C,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
which of the following materials is the most dense?,(A) Metal (B) Mafic rock (C) Felsic rock (D) Mantle rock,A,"You are going to visit a friend. You fill one backpack with books so you can study later. You stuff your pillow into another backpack that is the same size. Which backpack will be easier to carry? Even though the backpacks are the same size, the bag that contains your books is going to be much heavier. It has a greater density than the backpack with your pillow. Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Mass is a measure of the amount of matter in an object. The amount of space an object takes up is described by its volume. The density of an object depends on its mass and its volume. Density can be calculated using the following equation: Density = Mass/Volume Samples that are the same size, but have different densities, will have different masses. Gold has a density of about 19 g/cm3 . Pyrite has a density of only about 5 g/cm3 . Quartz is even less dense than pyrite, and has a density of 2.7 g/cm3 . If you picked up a piece of pyrite and a piece of quartz that were the same size, the pyrite would seem almost twice as heavy as the quartz. "
iron and nickel are both magnetic.,(A) True (B) False,A,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
we cant travel to the center of the earth in a volcanic tube because the pressure is so great it would close any tube that existed.,(A) True (B) False,A,"Supervolcano eruptions are extremely rare in Earths history. Its a good thing because they are unimaginably large. A supervolcano must erupt more than 1,000 cubic km (240 cubic miles) of material, compared with 1.2 km3 for Mount St. Helens or 25 km3 for Mount Pinatubo, a large eruption in the Philippines in 1991. Not surprisingly, supervolcanoes are the most dangerous type of volcano. "
without earths magnetic field,(A) Compasses would not work (B) Solar winds would strip away ozone from the atmosphere (C) Life would be exposed to ultraviolet radiation (D) All of the above,D,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
what generates earths magnetic field?,(A) Convection in the atmosphere (B) A giant bar magnet inside the planet (C) Convection in the liquid outer core (D) Solar wind,C,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
earths magnetic field,(A) Has a north and south pole (B) Behaves like iron filings are inside the planet (C) Arises due to radiation in the liquid outer core (D) All of these,A,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
sometimes earths magnetic north pole becomes its magnetic south pole and vice versa.,(A) True (B) False,A,"Many times during Earth history, even relatively recent Earth history, the planets magnetic field has flipped. That is, the north pole becomes the south pole and the south pole becomes the north pole. Scientists are not sure why this happens. One hypothesis is that the convection that drives the magnetic field becomes chaotic and then reverses itself. Another hypothesis is that an external event, such as an asteroid impact, disrupts motions in the core and causes the reversal. The first hypothesis is supported by computer models, but the second does not seem to be supported by much data. There is little correlation between impact events and magnetic reversals. Click image to the left or use the URL below. URL:  Earths magnetic field is like a bar magnet resides in the center of the planet. "
scientists know that the reason the magnetic field flips is this:,(A) Convection becomes chaotic and reverse direction (B) An asteroid impact disrupts motions in the core (C) Excess volcanism causes chaos in the mantle (D) None of these; scientists do now know why this happens,D,"Many times during Earth history, even relatively recent Earth history, the planets magnetic field has flipped. That is, the north pole becomes the south pole and the south pole becomes the north pole. Scientists are not sure why this happens. One hypothesis is that the convection that drives the magnetic field becomes chaotic and then reverses itself. Another hypothesis is that an external event, such as an asteroid impact, disrupts motions in the core and causes the reversal. The first hypothesis is supported by computer models, but the second does not seem to be supported by much data. There is little correlation between impact events and magnetic reversals. Click image to the left or use the URL below. URL:  Earths magnetic field is like a bar magnet resides in the center of the planet. "
scientists model magnetic reversals to try to determine why they occur.,(A) True (B) False,A,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
the outer core is made of,(A) Iron alone (B) Iron and nickel (C) Peridotite (D) Peridotite (E) iron and nickel,B,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
which of these is a possibility for why earths magnetic field has flipped?,(A) The convection currents reversed itself (B) An asteroid impact disrupted the motion in the core (C) The heat from the sun (D) Both a and b,D,"Many times during Earth history, even relatively recent Earth history, the planets magnetic field has flipped. That is, the north pole becomes the south pole and the south pole becomes the north pole. Scientists are not sure why this happens. One hypothesis is that the convection that drives the magnetic field becomes chaotic and then reverses itself. Another hypothesis is that an external event, such as an asteroid impact, disrupts motions in the core and causes the reversal. The first hypothesis is supported by computer models, but the second does not seem to be supported by much data. There is little correlation between impact events and magnetic reversals. Click image to the left or use the URL below. URL:  Earths magnetic field is like a bar magnet resides in the center of the planet. "
earths magnetic field has disappeared for long periods of time in earth history.,(A) True (B) False,B,"Many times during Earth history, even relatively recent Earth history, the planets magnetic field has flipped. That is, the north pole becomes the south pole and the south pole becomes the north pole. Scientists are not sure why this happens. One hypothesis is that the convection that drives the magnetic field becomes chaotic and then reverses itself. Another hypothesis is that an external event, such as an asteroid impact, disrupts motions in the core and causes the reversal. The first hypothesis is supported by computer models, but the second does not seem to be supported by much data. There is little correlation between impact events and magnetic reversals. Click image to the left or use the URL below. URL:  Earths magnetic field is like a bar magnet resides in the center of the planet. "
"without earths magnetic field, complex life could probably not exist.",(A) True (B) False,A,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
earths shape is,(A) A sphere (B) An oblate spheroid (C) A perfect circle (D) Flat,B,"Earth is a sphere or, more correctly, an oblate spheroid, which is a sphere that is a bit squished down at the poles and bulges a bit at the Equator. To be more technical, the minor axis (the diameter through the poles) is smaller than the major axis (the diameter through the Equator). Half of the sphere is a hemisphere. North of the Equator is the northern hemisphere and south of the Equator is the southern hemisphere. Eastern and western hemispheres are also designated. What evidence is there that Earth is spherical? What evidence was there before spaceships and satellites? Try to design an experiment involving a ship and the ocean to show Earth is round. If you are standing on the shore and a ship is going out to sea, the ship gets smaller as it moves further away from you. The ships bottom also starts to disappear as the vessel goes around the arc of the planet (Figure 1.1). There are many other ways that early scientists and mariners knew that Earth was not flat. The Sun and the other planets of the solar system are also spherical. Larger satellites, those that have enough mass for their gravitational attraction to have made them round, are spherical as well. Earths actual shape is not spherical but an oblate spheroid. The planet bulges around the equator due to mass collecting in the middle due to rotational momentum. "
between the equator and the north pole is earths,(A) Northern quartersphere (B) Northern halfsphere (C) Northern hemisphere (D) Northern demisphere,C,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
the planets of the solar system are spherical because of,(A) Centrifugal force (B) Gravity (C) Their spin (D) Their rock type,B,"To figure out how the solar system formed, we need to put together what we have learned. There are two other important features to consider. First, all the planets orbit in nearly the same flat, disk-like region. Second, all the planets orbit in the same direction around the Sun. These two features are clues to how the solar system formed. "
earths hemispheres are,(A) Northern and southern (B) Eastern and western (C) Northeastern and southwestern (D) Northern (E) southern (F) eastern and western,B,"Earth is a sphere or, more correctly, an oblate spheroid, which is a sphere that is a bit squished down at the poles and bulges a bit at the Equator. To be more technical, the minor axis (the diameter through the poles) is smaller than the major axis (the diameter through the Equator). Half of the sphere is a hemisphere. North of the Equator is the northern hemisphere and south of the Equator is the southern hemisphere. Eastern and western hemispheres are also designated. What evidence is there that Earth is spherical? What evidence was there before spaceships and satellites? Try to design an experiment involving a ship and the ocean to show Earth is round. If you are standing on the shore and a ship is going out to sea, the ship gets smaller as it moves further away from you. The ships bottom also starts to disappear as the vessel goes around the arc of the planet (Figure 1.1). There are many other ways that early scientists and mariners knew that Earth was not flat. The Sun and the other planets of the solar system are also spherical. Larger satellites, those that have enough mass for their gravitational attraction to have made them round, are spherical as well. Earths actual shape is not spherical but an oblate spheroid. The planet bulges around the equator due to mass collecting in the middle due to rotational momentum. "
it wasnt until johannes kepler that people realized that earth was round.,(A) True (B) False,B,"Ptolemys geocentric model worked, but it was complicated and occasionally made errors in predicting the movement of planets. At the beginning of the 16th century A.D., Nicolaus Copernicus proposed that Earth and all the other planets orbit the Sun. With the Sun at the center, this model is called the heliocentric model, or ""sun-centered"" model. Although Copernicus model was simpler - it didnt need epicycles and deferents - it still did not perfectly describe the motion of the planets. Johannes Kepler solved the problem a short time later when he determined that the planets moved around the Sun in ellipses (ovals), not circles (Figure 1.2). Keplers model matched observations perfectly. The heliocentric model did not catch on right away. When Galileo Galilei first turned a telescope to the heavens in 1610, he made several striking discoveries. Galileo discovered that the planet Jupiter has moons orbiting around it. This provided the first evidence that objects could orbit something besides Earth. Galileo also discovered that Venus has phases like the Moon (Figure 1.3), which provides direct evidence that Venus orbits the Sun. Galileos discoveries caused many more people to accept the heliocentric model of the universe, although Galileo himself was found guilty of heresy. The shift from an Earth-centered view to a Sun-centered view of the universe is referred to as the Copernican Revolution. In their elliptical orbits, each planet is sometimes farther away from the Sun than at other times. This movement is called revolution. At the same time, Earth spins on its axis. Earths axis is an imaginary line passing through the Keplers model showed the planets moving around the Sun in ellipses. The phases of Venus. planets center that goes through both the North Pole and the South Pole. This spinning movement is called Earths rotation. "
earths shape is a bit squished at the poles and bulges at the equator.,(A) True (B) False,A,"Earth is a sphere or, more correctly, an oblate spheroid, which is a sphere that is a bit squished down at the poles and bulges a bit at the Equator. To be more technical, the minor axis (the diameter through the poles) is smaller than the major axis (the diameter through the Equator). Half of the sphere is a hemisphere. North of the Equator is the northern hemisphere and south of the Equator is the southern hemisphere. Eastern and western hemispheres are also designated. What evidence is there that Earth is spherical? What evidence was there before spaceships and satellites? Try to design an experiment involving a ship and the ocean to show Earth is round. If you are standing on the shore and a ship is going out to sea, the ship gets smaller as it moves further away from you. The ships bottom also starts to disappear as the vessel goes around the arc of the planet (Figure 1.1). There are many other ways that early scientists and mariners knew that Earth was not flat. The Sun and the other planets of the solar system are also spherical. Larger satellites, those that have enough mass for their gravitational attraction to have made them round, are spherical as well. Earths actual shape is not spherical but an oblate spheroid. The planet bulges around the equator due to mass collecting in the middle due to rotational momentum. "
which of these is evidence that the earth is not flat?,(A) A ship going out to sea getting smaller as if moves further away from you (B) The shadows of the moon during a lunar eclipse (C) The sun rising and setting as an arc (D) All of the above,B,"Earth is a sphere or, more correctly, an oblate spheroid, which is a sphere that is a bit squished down at the poles and bulges a bit at the Equator. To be more technical, the minor axis (the diameter through the poles) is smaller than the major axis (the diameter through the Equator). Half of the sphere is a hemisphere. North of the Equator is the northern hemisphere and south of the Equator is the southern hemisphere. Eastern and western hemispheres are also designated. What evidence is there that Earth is spherical? What evidence was there before spaceships and satellites? Try to design an experiment involving a ship and the ocean to show Earth is round. If you are standing on the shore and a ship is going out to sea, the ship gets smaller as it moves further away from you. The ships bottom also starts to disappear as the vessel goes around the arc of the planet (Figure 1.1). There are many other ways that early scientists and mariners knew that Earth was not flat. The Sun and the other planets of the solar system are also spherical. Larger satellites, those that have enough mass for their gravitational attraction to have made them round, are spherical as well. Earths actual shape is not spherical but an oblate spheroid. The planet bulges around the equator due to mass collecting in the middle due to rotational momentum. "
this ancient civilization knew the earth was round.,(A) Romans (B) Greeks (C) Mayans (D) Aztecs,B,"The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD. "
earths minor axis is the diameter through its poles.,(A) True (B) False,A,"Earths axis is an imaginary line passing through the North and South Poles. Earthsrotation is its spins on its axis. Rotation is what a top does around its spindle. As Earth spins on its axis, it also orbits around the Sun. This is called Earths revolution. These motions lead to the cycles we see. Day and night, seasons, and the tides are caused by Earths motions. "
the diameter through the poles is larger than the diameter through the equator.,(A) True (B) False,B,"Imagine a huge bar magnet passing through Earths axis, as in the Figure 1.1. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles. A magnetic pole is the north or south end of a magnet, where the magnet exerts the most force. "
a total solar eclipse is when,(A) The Sun’s shadow completely blocks the Moon (B) The Moon’s shadow completely blocks the Sun (C) The Earth’s shadow completely blocks the Sun (D) The Earth’s shadow completely blocks the Moon,B,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
during a solar eclipse,(A) The Moon passes directly between the Earth and the Sun (B) The Sun passes directly between the Earth and Moon (C) The Earth passes directly between the Sun and Moon (D) None of the above,A,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
a solar eclipse occurs when the moons shadow completely blocks the sun.,(A) True (B) False,A,"A solar eclipse occurs when the new Moon passes directly between the Earth and the Sun (Figure 1.1). This casts a shadow on the Earth and blocks Earths view of the Sun. A total solar eclipse occurs when the Moons shadow completely blocks the Sun (Figure 1.2). When only a portion of the Sun is out of view, it is called a partial solar eclipse. Solar eclipses are rare and usually only last a few minutes because the Moon casts only a small shadow (Figure 1.3). As the Sun is covered by the Moons shadow, it will actually get cooler outside. Birds may begin to sing, and stars will become visible in the sky. During a solar eclipse, the corona and solar prominences can be seen. A solar eclipse occurs when the Moon passes between Earth and the Sun in such a way that the Sun is either partially or totally hidden from view. Some people, including some scientists, chase eclipses all over the world to learn or just observe this amazing phenomenon. A solar eclipse shown as a series of pho- tos. Click image to the left or use the URL below. URL: "
solar eclipses last only a few minutes because the moon casts a small shadow.,(A) True (B) False,A,"When a new moon passes directly between the Earth and the Sun, it causes a solar eclipse (Figure 24.20). The Moon casts a shadow on the Earth and blocks our view of the Sun. This happens only all three are lined up and in the same plane. This plane is called the ecliptic. The ecliptic is the plane of Earths orbit around the Sun. The Moons shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moons shadow. It is where the light is only partially blocked. When the Moons shadow completely blocks the Sun, it is a total solar eclipse (Figure 24.21). If only part of the Sun is out of view, it is a partial solar eclipse. Solar eclipses are rare events. They usually only last a few minutes. That is because the Moons shadow only covers a very small area on Earth and Earth is turning very rapidly. Solar eclipses are amazing to experience. It appears like night only strange. Birds may sing as they do at dusk. Stars become visible in the sky and it gets colder outside. Unlike at night, the Sun is out. So during a solar eclipse, its easy to see the Suns corona and solar prominences. This NASA page will inform you on when solar eclipses are expected: http://eclipse.gsfc.nasa.gov/solar.html "
"during a lunar eclipse, darkness in the middle of the day may cause temperatures to cool and stars to become visible.",(A) True (B) False,B,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
a lunar eclipse is when,(A) The Moon is between the Earth and Sun (B) The Sun is between the Earth and Moon (C) The Earth is in between the Sun and Moon (D) None of the above,C,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
"the inner, cone-shaped part of the shadow, in which all of the light has been blocked.",(A) Umbrella (B) Penumbra (C) Umbra (D) Pendulum,C,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
which of these is true of a total lunar eclipse?,(A) The whole moon enters Earth’s umbra (B) It lasts for hours (C) It can be viewed from any place on Earth that has a view of the Moon (D) All of these,D,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
"the penumbra is the inner, cone-shaped part of the shadow, in which all light has been blocked.",(A) True (B) False,B,"A lunar eclipse occurs when the full moon moves through Earths shadow, which only happens when Earth is between the Moon and the Sun and all three are lined up in the same plane, called the ecliptic (Figure 1.4). In an eclipse, Earths shadow has two distinct parts: the umbra and the penumbra. The umbra is the inner, cone-shaped part of the shadow, in which all of the light has been blocked. The penumbra is the outer part of Earths shadow where only part of the light is blocked. In the penumbra, the light is dimmed but not totally absent. A total lunar eclipse occurs when the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. Earths shadow is large enough that a lunar eclipse lasts for hours and can be seen by any part of Earth with a view of the Moon at the time of the eclipse (Figure 1.5). A lunar eclipse does not occur every month because Moons orbit is inclined 5-degrees to Earths orbit, so the two bodies are not in the same plane every month. "
why dont we see a lunar eclipse once each month?,(A) There is not a full moon that often (B) Earth and Moon’s orbits are not on exactly the same plane (C) There is one each month (D) but not always in the same location (E) d The Moon enters Earth’s penumbra each month (F) but not its umbra,B,"Sometimes a full moon moves through Earths shadow. This is a lunar eclipse (Figure 24.22). During a total lunar eclipse, the Moon travels completely in Earths umbra. During a partial lunar eclipse, only a portion of the Moon enters Earths umbra. When the Moon passes through Earths penumbra, it is a penumbral eclipse. Since Earths shadow is large, a lunar eclipse lasts for hours. Anyone with a view of the Moon can see a lunar eclipse. Partial lunar eclipses occur at least twice a year, but total lunar eclipses are less common. The Moon glows with a dull red coloring during a total lunar eclipse. "
the polar regions receive the most solar radiation because their summer days are 6 month long.,(A) True (B) False,B,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
"in the polar region, the night lasts",(A) For 12 hours (B) For 6 days (C) For 6 hours (D) For 6 months,D,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
the number of hours of daylight is equal all year long at the equator.,(A) True (B) False,A,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
what causes western europe to be warmer than the rest of europe?,(A) The Gulf Stream (B) The Benguela Current (C) The Arctic Current (D) The East Australian Current,A,"Its easy to see the difference in temperature at different latitudes in the Figure 1.1. But temperature is not completely correlated with latitude. There are many exceptions. For example, notice that the western portion of South America The maximum annual temperature of the Earth, showing a roughly gradual temperature gradient from the low to the high latitudes. has relatively low temperatures due to the Andes Mountains. The Rocky Mountains in the United States also have lower temperatures due to high altitudes. Western Europe is warmer than it should be due to the Gulf Stream. Click image to the left or use the URL below. URL: "
latitude is the only factor that determines the temperature of a region.,(A) True (B) False,B,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
"at the equator, the sun is just about directly overhead at midday.",(A) True (B) False,A,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
"the equatorial region in south america should be hot, but is actually cool. there is a similar zone of cool at nearly the same latitude in africa. what is the reason for these equatorial cool zones?",(A) Rising warm air causes precipitation and leads to the growth of rainforests (B) High plateaus collect snow and ice so there is high albedo (C) Sinking air from higher in the atmosphere brings cool air downward (D) None of these,A,"Earth is hottest at the equator and gets cooler toward the poles. The differences in heating create huge convection currents in the troposphere. At the equator, for example, warm air rises up to the tropopause. It cant rise any higher, so it flows north or south. By the time the moving air reaches 30 N or S latitude, it has cooled. The cool air sinks to the surface. Then it flows over the surface back to the equator. Other global winds occur in much the same way. There are three enormous convection cells north of the equator and three south of the equator. "
what prevents the poles from getting sunlight half the year?,(A) Earth’s elliptical orbit (B) The tilt of Earth’s axis of rotation (C) The high albedo of the polar regions (D) None of these,B,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
"if a map of temperature displayed stripes parallel to the equator with equal temperatures the distance north and south of the equator, it would mean that only __________ affected temperature.",(A) Longitude (B) Altitude (C) Latitude (D) Albedo,C,"Temperature changes with latitude. You can see how in Figure 17.2 At the equator, the Suns rays are most direct. Temperatures are highest. At higher latitudes, the Suns rays are less direct. The farther an area is from the equator, the lower is its temperature. At the poles, the Suns rays are least direct. Much of the area is covered with ice and snow, which reflect a lot of sunlight. Temperatures are lowest here. "
"which of these can cause lung disease and increased rates of asthma, emphysema, and viral infections?",(A) Particulates (B) Nitrogen oxide (C) Sulfur oxide (D) All of the above,D,"Common diseases of the respiratory system include asthma, pneumonia, and emphysema. All of them are diseases of the lungs. You can see some of the changes in the lungs that occur in each of these diseases in Figure 19.4. Asthma is a disease in which bronchioles in the lungs periodically swell and fill with mucus. Symptoms of asthma may include difficulty breathing, wheezing, coughing, and chest tightness. An asthma attack may be triggered by allergies, strenuous exercise, stress, or another respiratory illness such as a cold. Pneumonia is a disease in which some of the alveoli of the lungs fill with fluid so they can no longer exchange gas. Symptoms of pneumonia typically include coughing, chest pain, difficulty breathing, and fatigue. Pneumonia may be caused by an infection or an injury to the lungs. Emphysema is a disease in which the walls of the alveoli break down so less gas can be exchanged by the lungs. The main symptom of emphysema is shortness of breath. The damage to the alveoli is usually caused by smoking and is permanent. "
high ozone levels cause,(A) Diseases of the reproductive system (B) Heart and lung disease (C) Gastrointestinal diseases (D) All of the above,B,"The ozone in smog may damage plants. The effects of ozone add up over time. Plants such as trees, which normally live a long time, are most affected. Entire forests may die out if ozone levels are very high. Other plants, including crop plants, may also be damaged by ozone. You can see evidence of ozone damage in Figure 22.5. The ozone in smog is also harmful to human health. Figure 22.6 shows the levels of ozone to watch out for. Some people are especially sensitive to ozone. They can be harmed by levels of ozone that would not affect most other people. These people include those with lung or heart problems. "
"in the united states, particulates are responsible for this many deaths a year.",(A) 300 (B) 3 (C) 000 (D) c 30 (E) 000 (F) d 300 (G) 000,C,Human health suffers in locations with high levels of air pollution. 
shutting down vehicle traffic in a region results in a reduction in,(A) Hospital visits due to asthma (B) Gastrointestinal diseases (C) Anemia (D) All of the above,A,"Particulates reduce visibility. In the western United States, people can now ordinarily see only about 100 to 150 kilometers (60 to 90 miles), which is one-half to two-thirds the natural (pre-pollution) range on a clear day. In the East, people can only see about 40 to 60 kilometers (25-35 miles), about one-fifth the distance they could see without any air pollution (Figure 1.1). Particulates reduce the amount of sunshine that reaches the ground, which may reduce photosynthesis. Since particulates form the nucleus for raindrops, snowflakes, or other forms of precipitation, precipitation may increase Smog in New York City. when particulates are high. An increase in particles in the air seems to increase the number of raindrops, but often decreases their size. By reducing sunshine, particulates can also alter air temperature as mentioned above. Imagine how much all of the sources of particulates combine to reduce temperatures. What affect might this have on global warming? "
"due to air pollution, this disease is increasing, even for people who do not smoke.",(A) Stroke (B) Heart disease (C) Asthma (D) Lung cancer,D,Human health suffers in locations with high levels of air pollution. 
scientists are certain that the increase in air pollution is causing the increase in lung cancer.,(A) True (B) False,B,"Many but not all cases of asthma can be linked to air pollution. During the 1996 Olympic Games, Atlanta, Georgia, closed off their downtown to private vehicles. This action decreased ozone levels by 28%. At the same time, there were 40% fewer hospital visits for asthma. Can scientists conclude without a shadow of a doubt that the reduction in ozone caused the reduction in hospital visits? What could they do to make that determination? Lung cancer among people who have never smoked is around 15% and is increasing. One study showed that the risk of being afflicted with lung cancer increases directly with a persons exposure to air pollution (Figure 1.1). The study concluded that no level of air pollution should be considered safe. Exposure to smog also increased the risk of dying from any cause, including heart disease. One study found that in the United States, children develop asthma at more than twice the rate of two decades ago and at four times the rate of children in Canada. Adults also suffer from air pollution-related illnesses that include lung disease, heart disease, lung cancer, and weakened immune systems. The asthma rate worldwide is rising 20% to 50% every decade. "
a person exposed to air pollution is more likely to get lung cancer.,(A) True (B) False,A,"Many but not all cases of asthma can be linked to air pollution. During the 1996 Olympic Games, Atlanta, Georgia, closed off their downtown to private vehicles. This action decreased ozone levels by 28%. At the same time, there were 40% fewer hospital visits for asthma. Can scientists conclude without a shadow of a doubt that the reduction in ozone caused the reduction in hospital visits? What could they do to make that determination? Lung cancer among people who have never smoked is around 15% and is increasing. One study showed that the risk of being afflicted with lung cancer increases directly with a persons exposure to air pollution (Figure 1.1). The study concluded that no level of air pollution should be considered safe. Exposure to smog also increased the risk of dying from any cause, including heart disease. One study found that in the United States, children develop asthma at more than twice the rate of two decades ago and at four times the rate of children in Canada. Adults also suffer from air pollution-related illnesses that include lung disease, heart disease, lung cancer, and weakened immune systems. The asthma rate worldwide is rising 20% to 50% every decade. "
"in poorly ventilated spaces, such as tunnels, this gas can kill people.",(A) Carbon dioxide (B) Lead (C) Carbon monoxide (D) Methane,C,"Carbon monoxide (CO) is toxic to both plants and animals. CO is deadly to people in a confined space, such as a closed home. Carbon monoxide is odorless and colorless, so people cant tell when they are breathing it. Thats why homes should have carbon monoxide detectors. You can see one in Figure 22.7. "
breathing air into which weve emitted pollutants is not much different from throwing trash in our food supply and eating it.,(A) True (B) False,A,All air pollutants cause some damage to living creatures and the environment. Different types of pollutants cause different types of harm. 
"according to one study, no amount of air pollution is safe to breathe.",(A) True (B) False,A,Human health suffers in locations with high levels of air pollution. 
"if you live in a desert, the best car to buy to avoid a hot interior is one that is",(A) White (B) Yellow (C) Blue (D) Black,A,"Light may transfer its energy to matter rather than being reflected or transmitted by matter. This is called absorption. When light is absorbed, the added energy increases the temperature of matter. If you get into a car that has been sitting in the sun all day, the seats and other parts of the cars interior may be almost too hot to touch, especially if they are black or very dark in color. Thats because dark colors absorb most of the sunlight that strikes them. Q: In hot sunny climates, people often dress in light-colored clothes. Why is this a good idea? A: Light-colored clothes absorb less light and reflect more light than dark-colored clothes, so they keep people cooler. "
radiation transfers energy by electromagnetic waves.,(A) True (B) False,A,"Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Suns energy travels through space by radiation. After sunlight heats the planets surface, some heat radiates back into the atmosphere. "
the law of conservation of energy states that energy,(A) cannot be created (B) cannot be destroyed (C) can change forms (D) All of the above,D,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
violet light has the longest wavelengths for visible light.,(A) True (B) False,B,"Visible light consists of a range of wavelengths. The wavelength of visible light determines the color that the light appears. As you can see in Figure 22.4, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between is a continuum of all the other colors of light. Only a few colors of light are represented in the figure. "
plants convert solar energy to chemical energy.,(A) True (B) False,A,Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy ! C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose is used for energy by the cells of almost all living things. Plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). How do living things get energy from glucose? The answer is cellular respiration. 
the measure of how well a surface reflects light:,(A) Mirroring (B) Albedo (C) Refraction (D) Prism,B,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
a snow field has a low albedo.,(A) True (B) False,B,"Snow and ice may also undergo sublimation under certain conditions. This is most likely to happen where there is intense sunlight, very cold temperatures, and dry winds. These conditions are often found on mountain peaks. As snow sublimates, it gradually shrinks without any runoff of liquid water. Click image to the left or use the URL below. URL: "
why would it be adaptive for a snake to see infrared energy?,(A) As a reptile (B) it can then know where to go to warm up on cold mornings (C) b As an animal (D) it can avoid locations where infrared radiation is high (E) c As a predator (F) it is better able to locate a prey animal if it can “see” its body heat (G) d None of these,C,"Reptiles are tetrapods (four-legged) and ectothermic, meaning their internal temperature depends on the temperature of their environment. This is why you may see reptiles sunbathing as they use the energy from the sun to warm their bodies. Usually the sense organs of reptiles, like ears, are well developed, though snakes do not have external ears. All reptiles have advanced eyesight. Reptiles also have a sense of smell. Crocodilians, turtles, and tortoises smell like most other land vertebrates. But, some lizards, and all snakes, smell with their tongues, which is flicked out of the mouth to pick up scent molecules from the air. Reptiles also have several adaptations for living on land. They have a skin covered in scales to protect them from drying out. All reptiles have lungs to breathe air. Reptiles are also amniotes, which means their embryos are surrounded by a thin membrane. This membrane protects the embryo from the harsh conditions of living on land. Reptile eggs are also surrounded by a protective shell, which may be either flexible or inflexible. "
"this breaks up light into different wavelengths, separating light into different colors.",(A) Mirror (B) Prism (C) Glass (D) Screen,B,"A prism, like the one in Figure 22.5, can be used to separate visible light into its different colors. A prism is a pyramid-shaped object made of transparent matter, usually clear glass. It transmits light but slows it down. When light passes from the air to the glass of the prism, the change in speed causes the light to bend. Different wavelengths of light bend at different angles. This causes the beam of light to separate into light of different wavelengths. What we see is a rainbow of colors. Look back at the rainbow that opened this chapter. Do you see all the different colors of light, from red at the top to violet at the bottom? Individual raindrops act as tiny prisms. They separate sunlight into its different wavelengths and create a rainbow. For an animated version of Figure 22.5, go to the URL: http://en.wikipedia.org/wiki/File:Light_dispersion_conce "
which two items radiate energy?,(A) A mirror and a prism (B) The moon and Jupiter (C) The moon and the sun (D) The sun and a light bulb,D,"Energy travels through space or material. This is obvious when you stand near a fire and feel its warmth or when you pick up the handle of a metal pot even though the handle is not sitting directly on the hot stove. Invisible energy waves can travel through air, glass, and even the vacuum of outer space. These waves have electrical and magnetic properties, so they are called electromagnetic waves. The transfer of energy from one object to another through electromagnetic waves is known as radiation. Different wavelengths of energy create different types of electromagnetic waves (Figure 1.1). The wavelengths humans can see are known as visible light. When viewed together, all of the wavelengths of visible light appear white. But a prism or water droplets can break the white light into different wavelengths so that separate colors appear (Figure 1.2). What objects can you think of that radiate visible light? Two include the Sun and a light bulb. The longest wavelengths of visible light appear red. Infrared wavelengths are longer than visible red. Snakes can see infrared energy. We feel infrared energy as heat. Wavelengths that are shorter than violet are called ultraviolet. Can you think of some objects that appear to radiate visible light, but actually do not? The Moon and the planets do not emit light of their own; they reflect the light of the Sun. Reflection is when light (or another wave) bounces back from a surface. Albedo is a measure of how well a surface reflects light. A surface with high albedo reflects a large percentage of light. A snow field has high albedo. One important fact to remember is that energy cannot be created or destroyed  it can only be changed from one form to another. This is such a fundamental fact of nature that it is a law: the law of conservation of energy. In photosynthesis, for example, plants convert solar energy into chemical energy that they can use. They do not create new energy. When energy is transformed, some nearly always becomes heat. Heat transfers between materials easily, from warmer objects to cooler ones. If no more heat is added, eventually all of a material will reach the same temperature. "
what are two ways that energy can be conserved?,(A) Use less energy (B) Create more energy (C) as needed (D) c Use energy more efficiently (E) d Use less energy and use energy more efficiently,A,We can reduce our use of energy resources and the pollution they cause by conserving energy. Conservation means saving resources by using them more efficiently or not using them at all. Figure 17.24 shows several ways that people can conserve energy in their daily lives. You can find more energy-saving tips at the URL below. What do you do to save energy? What else could you do? 
"in 2004, the united states used most of its energy on ________________.",(A) Transportation (B) Residential use (C) Industrial use (D) Commercial use,A,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
which of these are ways we can use less energy in our homes?,(A) Turn off lights when not in a room (B) Only run appliances when necessary (C) Use a fan instead of an air conditioner (D) All of the above,D,"There are many ways to use less energy. Table 20.2 lists some of them. Can you think of other ways to use less energy? For example, how might schools use less energy? Use of Energy Transportation How to Use Less Plan ahead to reduce the number of trips you make. Take a bus or train instead of driving. Walk or bike rather than ride. Home Unplug appliances when not in use. Turn off lights when you leave a room. Put on a sweater instead of turning up the heat. Run the dishwasher and washing machine only when full. "
"if you are driving, you can use energy more efficiently if you drive ___________.",(A) Above 90 miles per hour (B) Below 55 miles per hour (C) Above 55 miles per hour (D) Between 60 and 70 miles per hour,B,"Much of the energy used in the U.S. is used for transportation. You can conserve transportation energy in several ways. For example, you can: plan ahead to avoid unnecessary trips. take public transit such as subways (see Figure 1.1) instead of driving. drive an energy-efficient vehicle when driving is the only way to get there. Q: What are some other ways you could save energy in transportation? A: You could carpool to save transportation energy. Even if you carpool with just one other person, thats one less vehicle on the road. For short trips, you could ride a bike or walk to you destination. The extra exercise is another benefit of using your own muscle power to get where you need to go. "
"in a business, it is possible to conserve energy by",(A) Using incandescent lights (B) Setting thermostats to turn off when buildings are empty (C) Keeping appliances plugged in so they are ready to go on Monday morning (D) All of these,B,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
conserving energy is cleaner and cheaper than finding new energy.,(A) True (B) False,A,We can reduce our use of energy resources and the pollution they cause by conserving energy. Conservation means saving resources by using them more efficiently or not using them at all. Figure 17.24 shows several ways that people can conserve energy in their daily lives. You can find more energy-saving tips at the URL below. What do you do to save energy? What else could you do? 
why is it good to conserve energy?,(A) Sources of energy that are limited will be available in the future (B) It is much cheaper to conserve energy than to develop new energy sources (C) Energy that is not used does not produce pollution (D) All of these,D,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
which type of light is more energy efficient?,(A) Incandescent Lights (B) LEAD bulbs (C) Compact fluorescent bulbs (D) None of these,C,"LED stands for light-emitting diode. An LED light contains a material called a semi-conductor, which gives off visible light when an electric current flows through it. LED lights are used for traffic lights (see Figure 1.5) and also indicator lights on computers, cars, and many other devices. This type of light is very reliable and durable. Q: Some light bulbs produce a lot of heat in addition to visible light, so they waste energy. Other bulbs produce much less heat, so they use energy more efficiently. Which light bulbs described above would you place in each category? A: Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. The other light bulbs produce light by some type of luminescence, in which light is produced without heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use? "
to be energy efficient at home,(A) Use old appliances (B) even if they no longer run well (C) b Make sure your home is well insulated (D) c Keep the heat (or air conditioning (E) d All of these,B,"Many people waste energy at home, so a lot of energy can be saved there as well. What can you do to conserve energy? You can: turn off lights and unplug appliances and other electrical devices when not in use. use energy-efficient light bulbs and appliances. turn the thermostat down in winter and up in summer. Q: How can you tell which light bulbs and appliances use less energy? "
using energy more efficiently will help our energy resources last a longer time.,(A) True (B) False,A,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
which of the following can be used as biofuel?,(A) Almond shells (B) Algae (C) Corn (D) All of these,D,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
"compared to other forms of renewable energy, biomass energy",(A) Is less reliable (B) Burns more cleanly (C) with less greenhouse gas emissions (D) c Can be processed into a liquid for use in cars (E) d All of these,C,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
fossil fuels burn cleaner than biofuels.,(A) True (B) False,B,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
"cow manure can be a source of methane gas, which can be converted to electricity.",(A) True (B) False,A,"Biomass is the material that comes from plants and animals that were recently living. Biomass can be burned directly, such as setting fire to wood. For as long as humans have had fire, people have used biomass for heating and cooking. People can also process biomass to make fuel, called biofuel. Biofuel can be created from crops, such as corn or Biofuels, such as ethanol, are added to gasoline to cut down the amount of fossil fuels that are used. algae, and processed for use in a car (Figure 1.1). The advantage to biofuels is that they burn more cleanly than fossil fuels. As a result, they create less pollution and less carbon dioxide. Organic material, like almond shells, can be made into electricity. Biomass power is a great use of wastes and is more reliable than other renewable energy sources, but harvesting biomass energy uses energy and biomass plants produce pollutants including greenhouse gases. Cow manure can have a second life as a source of methane gas, which can be converted to electricity. Not only that food scraps can also be converted into green energy. Food that is tossed out produces methane, a potent greenhouse gas. But that methane from leftovers can be harnessed and used as fuel. Sounds like a win-win situation. "
the considerations needed when using biomass for fuel includes,(A) Many crops need fertilizers to grow (B) which can become pollutants (C) b Some crops emit no greenhouse gases when burned (D) c Crops are more efficient than wastes as biofuels (E) d All of these,A,"Biomass is the material that comes from plants and animals that were recently living. Biomass can be burned directly, such as setting fire to wood. For as long as humans have had fire, people have used biomass for heating and cooking. People can also process biomass to make fuel, called biofuel. Biofuel can be created from crops, such as corn or Biofuels, such as ethanol, are added to gasoline to cut down the amount of fossil fuels that are used. algae, and processed for use in a car (Figure 1.1). The advantage to biofuels is that they burn more cleanly than fossil fuels. As a result, they create less pollution and less carbon dioxide. Organic material, like almond shells, can be made into electricity. Biomass power is a great use of wastes and is more reliable than other renewable energy sources, but harvesting biomass energy uses energy and biomass plants produce pollutants including greenhouse gases. Cow manure can have a second life as a source of methane gas, which can be converted to electricity. Not only that food scraps can also be converted into green energy. Food that is tossed out produces methane, a potent greenhouse gas. But that methane from leftovers can be harnessed and used as fuel. Sounds like a win-win situation. "
"to create biomass energy, breakdown of the ______ of plants is needed.",(A) Mitochondria (B) Cell walls (C) Cytoplasm (D) Nucleus,B,"Biomass is the material that comes from plants and animals that were recently living. Biomass can be burned directly, such as setting fire to wood. For as long as humans have had fire, people have used biomass for heating and cooking. People can also process biomass to make fuel, called biofuel. Biofuel can be created from crops, such as corn or Biofuels, such as ethanol, are added to gasoline to cut down the amount of fossil fuels that are used. algae, and processed for use in a car (Figure 1.1). The advantage to biofuels is that they burn more cleanly than fossil fuels. As a result, they create less pollution and less carbon dioxide. Organic material, like almond shells, can be made into electricity. Biomass power is a great use of wastes and is more reliable than other renewable energy sources, but harvesting biomass energy uses energy and biomass plants produce pollutants including greenhouse gases. Cow manure can have a second life as a source of methane gas, which can be converted to electricity. Not only that food scraps can also be converted into green energy. Food that is tossed out produces methane, a potent greenhouse gas. But that methane from leftovers can be harnessed and used as fuel. Sounds like a win-win situation. "
biomass from which sugars are released and fermented create fuel.,(A) True (B) False,A,"In many instances, the amount of energy, fertilizer, and land needed to produce the crops used make biofuels mean that they often produce very little more energy than they consume. The fertilizers and pesticides used to grow the crops run off and become damaging pollutants in nearby water bodies or in the oceans. To generate biomass energy, break down the cell walls of plants to release the sugars and then ferment those sugars to create fuel. Corn is a very inefficient source; scientists are looking for much better sources of biomass energy. "
wood has been one of the oldest fuels used for warmth or to cook food.,(A) True (B) False,A,"When fuel is burned, most of the energy is released as heat. Some of this heat can be used to do work. Heat cooks food or warms your house. Sometimes the heat is just waste heat. It still heats the environment, though. Heat from a fire can boil a pot of water. If you put an egg in the pot, you can eat a hard boiled egg in 15 minutes (cool it down first!). The energy to cook the egg was stored in the wood. The wood got that energy from the Sun when it was part of a tree. The Sun generated the energy by nuclear fusion. You started the fire with a match. The head of the match stores energy as chemical energy. That energy lights the wood on fire. The fire burns as long as there is energy in the wood. Once the wood has burned up, there is no energy left in it. The fire goes out. "
why is algae considered a better option as source of biofuels than corn?,(A) Algae is easier to convert to a usable fuel (B) Algae can be grown in locations where crops can’t (C) Algae can thrive on waste (D) All of the above,D,"Research is being done into alternative crops for biofuels. A very promising alternative is algae. Growing algae requires much less land and energy than crops. Algae can be grown in locations that are not used for other things, like in desert areas where other crops are not often grown. Algae can be fed agricultural and other waste so valuable resources are not used. Much research is being done to bring these alternative fuels to market. Many groups are researching the use of algae for fuel. Many people think that the best source of biomass energy for the future is algae. Compared to corn, algae is not a food crop, it can grow in many places, its much easier to convert to a usable fuel, and its carbon neutral. "
the most commonly used energy resource in the u.s. is,(A) oil (B) coal (C) natural gas (D) none of the above,A,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
all of the energy resources listed in question 1 are nonrenewable resources.,(A) true (B) false,A,"Look at the circle graph in the Figure 1.1. It shows that oil is the single most commonly used energy resource in the U.S., followed by natural gas, and then by coal. All of these energy resources are nonrenewable. Nonrenewable resources are resources that are limited in supply and cannot be replaced as quickly as they are used up. Renewable resources, in contrast, provide only 8 percent of all energy used in the U.S. Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. They include solar energy from sunlight, geothermal energy from under Earths surface, wind, biomass (from once-living things or their wastes), and hydropower (from running water). "
examples of renewable energy resources include,(A) wind energy (B) solar energy (C) biomass energy (D) all of the above,D,"Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table 17.1. Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. here? Renewable Energy Resource Sunlight The energy in sunlight, or solar energy, can be used to heat homes. It can also be used to produce electricity in solar cells. However, solar energy may not be practical in areas that are often cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water When water falls downhill, its potential energy is con- verted to kinetic energy that can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream and reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air, so it has kinetic energy that can do work. Remember the wind turbines that opened this chapter? Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy and unattractive in the landscape. Water flowing through Hoover dam between Arizona and Nevada generates electricity for both of these states and also by southern California. The dam spans the Colorado River. This old-fashioned windmill captures wind energy that is used for pumping water out of a well. Windmills like this one have been used for centuries. Renewable Energy Resource Biomass The stored chemical energy of trees and other plants is called biomass energy. When plant materials are burned, they produce thermal energy that can be used for heating, cooking, or generating electricity. Biomassespecially woodis an important energy source in countries where most people cant afford fossil fuels. Some plants can also be used to make ethanol, a fuel that is added to gasoline. Ethanol produces less pollution than gasoline, but large areas of land are needed to grow the plants needed to make it. Geothermal Heat below Earths surfacecalled geothermal en- ergycan be used to produce electricity. A power plant pumps water underground where it is heated. Then it pumps the water back to the plant and uses its thermal energy to generate electricity. On a small scale, geothermal energy can be used to heat homes. Installing a geothermal system can be very costly, how- ever, because of the need to drill through underground rocks. Example This large machine is harvesting and grinding plants to be used for biomass energy. This geothermal power plant is located in Italy where hot magma is close to the surface. "
"in the u.s., the most commonly used renewable energy resource is solar energy.",(A) true (B) false,B,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
people in the u.s. use far more energy per person than people in any other country.,(A) true (B) false,A,"People in the richer nations of the world use far more energy, especially energy from fossil fuels, than people in the poorer nations do. Figure 17.23 compares the amounts of oil used by the top ten oil-consuming nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels a year. Because richer nations use more fossil fuels, they also cause more air pollution and global warming than poorer nations do. "
the worlds top five oil-consuming nations include all of the following except,(A) India (B) Japan (C) Canada (D) China,C,"People in the richer nations of the world use far more energy, especially energy from fossil fuels, than people in the poorer nations do. Figure 17.23 compares the amounts of oil used by the top ten oil-consuming nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels a year. Because richer nations use more fossil fuels, they also cause more air pollution and global warming than poorer nations do. "
the damage done by surface mining includes,(A) Clearing the landscape of trees and soil (B) Erosion of sediments into streams and lakes (C) Pollutants and acids flow outward from mines (D) All of these,D,"Although mining provides people with many needed resources, the environmental costs can be high. Surface mining clears the landscape of trees and soil, and nearby streams and lakes are inundated with sediment. Pollutants from the mined rock, such as heavy metals, enter the sediment and water system. Acids flow from some mine sites, changing the composition of nearby waterways (Figure 1.1). U.S. law has changed in recent decades so that a mine region must be restored to its natural state, a process called reclamation. This is not true of older mines. Pits may be refilled or reshaped and vegetation planted. Pits may be allowed to fill with water and become lakes or may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. Click image to the left or use the URL below. URL:  Acid drainage from a surface coal mine in Missouri. "
this product of mining can change the composition of nearby streams and lakes,(A) Water (B) Precious metals (C) Acids (D) All of the above,C,"Although mining provides people with many needed resources, the environmental costs can be high. Surface mining clears the landscape of trees and soil, and nearby streams and lakes are inundated with sediment. Pollutants from the mined rock, such as heavy metals, enter the sediment and water system. Acids flow from some mine sites, changing the composition of nearby waterways (Figure 1.1). U.S. law has changed in recent decades so that a mine region must be restored to its natural state, a process called reclamation. This is not true of older mines. Pits may be refilled or reshaped and vegetation planted. Pits may be allowed to fill with water and become lakes or may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. Click image to the left or use the URL below. URL:  Acid drainage from a surface coal mine in Missouri. "
acid flowing from coal mines in missouri polluted the water and land.,(A) True (B) False,A,Mining can cause pollution. Chemicals released from mining can contaminate nearby water sources. Figure 3.26 shows water that is contaminated from a nearby mine. The United States government has mining standards to protect water quality. 
older mines must also be reclaimed by u.s. law.,(A) True (B) False,B,"After the mining is finished, the land is greatly disturbed. The area around the mine needs to be restored to its natural state. This process of restoring the area is called reclamation. Native plants are planted. Pit mines may be refilled or reshaped so that they can become natural areas again. The mining company may be allowed to fill the pit with water to create a lake. The pits may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. "
reclamation of a mine area may include,(A) Filling pits with sediment (B) reshaping the land and planting vegetation (C) b Putting a cap on the mine and leaving (D) c Planting vegetation over the mine (E) d Reclamation is not a goal of most mine owners,A,"After the mining is finished, the land is greatly disturbed. The area around the mine needs to be restored to its natural state. This process of restoring the area is called reclamation. Native plants are planted. Pit mines may be refilled or reshaped so that they can become natural areas again. The mining company may be allowed to fill the pit with water to create a lake. The pits may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. "
personal electronics are full of metals and other substances that come from mining.,(A) True (B) False,A,"We rely on metals, such as aluminum, copper, iron, and gold. Look around the room. How many objects have metal parts? Metals are used in the tiny parts inside your computer, in the wires of anything that uses electricity, and to make the structure of a large building, such as the one shown in the Figure 3.23. "
how does mining affect streams and lakes?,(A) They may become full of sediment (B) They may become full of pollutants (C) They may become full of acid (D) All of these,D,"Although mining provides people with many needed resources, the environmental costs can be high. Surface mining clears the landscape of trees and soil, and nearby streams and lakes are inundated with sediment. Pollutants from the mined rock, such as heavy metals, enter the sediment and water system. Acids flow from some mine sites, changing the composition of nearby waterways (Figure 1.1). U.S. law has changed in recent decades so that a mine region must be restored to its natural state, a process called reclamation. This is not true of older mines. Pits may be refilled or reshaped and vegetation planted. Pits may be allowed to fill with water and become lakes or may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. Click image to the left or use the URL below. URL:  Acid drainage from a surface coal mine in Missouri. "
heavy metals are among the pollutants that can come off a mine.,(A) True (B) False,A,Mining can cause pollution. Chemicals released from mining can contaminate nearby water sources. Figure 3.26 shows water that is contaminated from a nearby mine. The United States government has mining standards to protect water quality. 
"according to u.s. law, a mine region",(A) May be left as it is when the mining is complete (B) Must be restored to its natural state (C) May be capped and left alone (D) None of these,B,"Although mining provides people with many needed resources, the environmental costs can be high. Surface mining clears the landscape of trees and soil, and nearby streams and lakes are inundated with sediment. Pollutants from the mined rock, such as heavy metals, enter the sediment and water system. Acids flow from some mine sites, changing the composition of nearby waterways (Figure 1.1). U.S. law has changed in recent decades so that a mine region must be restored to its natural state, a process called reclamation. This is not true of older mines. Pits may be refilled or reshaped and vegetation planted. Pits may be allowed to fill with water and become lakes or may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. Click image to the left or use the URL below. URL:  Acid drainage from a surface coal mine in Missouri. "
how can bats benefit from mining?,(A) Underground mines that are left open may become homes for bats (B) Insects are attracted to the mine smells and bats come to eat them (C) Bats eat the birds that live in an abandoned mine shaft (D) None of these,A,"After the mining is finished, the land is greatly disturbed. The area around the mine needs to be restored to its natural state. This process of restoring the area is called reclamation. Native plants are planted. Pit mines may be refilled or reshaped so that they can become natural areas again. The mining company may be allowed to fill the pit with water to create a lake. The pits may be turned into landfills. Underground mines may be sealed off or left open as homes for bats. "
how do scientists discover an extrasolar planet?,(A) The temporary dimming of a star as the planet crosses in front of it (B) A star’s movement toward and away from us along our line of sight (C) A state-of-the at space telescope (D) All of these,D,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
"even though they are so very far away, scientists are excited to find earth-like planets because they would like to find",(A) Evidence of intelligent life (B) Evidence of microbial life (C) A planet that looks like Earth (D) None of these,A,"How to Discover a New Planet Thousands of planets - ones that look totally different than what were used to, and possibly could support life, exist outside of our solar system. But were only just now starting to find them. In the video below, Ashley takes you behind the simple technique that astronomers have been using to discover these curious new planets. MEDIA Click image to the left or use the URL below. URL: "
there have been more than 1800 exoplanets identified and confirmed.,(A) True (B) False,A,"Since the early 1990s, astronomers have discovered other solar systems. A solar system has one or more planets orbiting one or more stars. We call these planets extrasolar planets, or exoplanets. They are called exoplanets because they orbit a star other than the Sun. As of June 2013, 891 exoplanets have been found. More exoplanets are found all the time. You can check out how many we have found at http://planetquest.jpl.nasa.gov/. We have been able to take pictures of only a few exoplanets. Most are discovered because of some tell-tale signs. One sign is a very slight motion of a star that must be caused by the pull of a planet. Another sign is the partial dimming of a stars light as the planet passes in front of it. "
exoplanets orbit a star other than the sun.,(A) True (B) False,A,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
what does it mean when a planet is in a stars habitable zone?,(A) It has oxygen in its atmosphere (B) It has a day-night cycle and a seasonal cycle that resembles Earth’s (C) It has the right temperature to have liquid water (D) All of the above,C,"In 2006, the International Astronomical Union decided that there were too many questions surrounding what could be called a planet, and so refined the definition of a planet. According to the new definition, a planet must: Orbit a star. Be big enough that its own gravity causes it to be shaped as a sphere. Be small enough that it isnt a star itself. Have cleared the area of its orbit of smaller objects. "
"if a planet is not centered on the disk of gas surrounding it, it may mean that",(A) The planet does not have a spherical shape (B) There is another planet that is pulling the gas toward it (C) The gas is not behaving like gas in our solar system (D) None of the above,B,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
when did scientists start discovering exoplanets?,(A) 1898 (B) 1890s (C) 1990s (D) 2000,C,"Since the early 1990s, astronomers have discovered other solar systems. A solar system has one or more planets orbiting one or more stars. We call these planets extrasolar planets, or exoplanets. They are called exoplanets because they orbit a star other than the Sun. As of June 2013, 891 exoplanets have been found. More exoplanets are found all the time. You can check out how many we have found at http://planetquest.jpl.nasa.gov/. We have been able to take pictures of only a few exoplanets. Most are discovered because of some tell-tale signs. One sign is a very slight motion of a star that must be caused by the pull of a planet. Another sign is the partial dimming of a stars light as the planet passes in front of it. "
"new extrasolar planets are identified very rarely, only about once per decade.",(A) True (B) False,B,"Since the early 1990s, astronomers have discovered other solar systems, with planets orbiting stars other than our own Sun. These are called ""extrasolar planets"" or simply exoplanets (see Figure 1.1). Exoplanets are not in our solar system, but are found in other solar systems. Some extrasolar planets have been directly imaged, but most have been discovered by indirect methods. One technique involves detecting the very slight motion of a star periodically moving toward and away from us along our line-of-sight (also known as a stars ""radial velocity""). This periodic motion can be attributed to the gravitational pull of a planet or, sometimes, another star orbiting the star. A planet may also be identified by measuring a stars brightness over time. A temporary, periodic decrease in light emitted from a star can occur when a planet crosses in front of, or ""transits,"" the star it is orbiting, momentarily blocking out some of the starlight. More than 1800 extrasolar planets have been identified and confirmed and the rate of discovery is increasing rapidly. Click image to the left or use the URL below. URL: "
scientists are more likely to detect a giant exoplanet because,(A) It has a greater effect on the star it orbits (B) It appears larger in earth-based telescopes (C) Giant exoplanets are many times more likely to exist (D) None of these,A,"Since the early 1990s, astronomers have discovered other solar systems. A solar system has one or more planets orbiting one or more stars. We call these planets extrasolar planets, or exoplanets. They are called exoplanets because they orbit a star other than the Sun. As of June 2013, 891 exoplanets have been found. More exoplanets are found all the time. You can check out how many we have found at http://planetquest.jpl.nasa.gov/. We have been able to take pictures of only a few exoplanets. Most are discovered because of some tell-tale signs. One sign is a very slight motion of a star that must be caused by the pull of a planet. Another sign is the partial dimming of a stars light as the planet passes in front of it. "
"according to statistical studies, the milky way galaxy may contain about 100 billion planets.",(A) True (B) False,B,"The Milky Way Galaxy is a spiral galaxy that contains about 400 billion stars. Like other spiral galaxies, it has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across. It is about 3,000 light years thick. Most of the galaxys gas, dust, young stars, and open clusters are in the disk. Some astronomers think that there is a gigantic black hole at the center of the galaxy. Figure 26.13 shows what the Milky Way probably looks like from the outside. Our solar system is within one of the spiral arms. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are a little more than halfway out from the center of the Galaxy to the edge, as shown in Figure 26.13. Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. "
this element was first discovered in our sun by analyzing the absorption lines.,(A) Hydrogen (B) Helium (C) Oxygen (D) Carbon,B,"If you look at a star through a prism, you will see a spectrum, or a range of colors through the rainbow. The spectrum will have specific dark bands where elements in the star absorb light of certain energies. By examining the arrangement of these dark absorption lines, astronomers can determine the composition of elements that make up a distant star. In fact, the element helium was first discovered in our Sun  not on Earth  by analyzing the absorption lines in the spectrum of the Sun. While studying the spectrum of light from distant galaxies, astronomers noticed something strange. The dark lines in the spectrum were in the patterns they expected, but they were shifted toward the red end of the spectrum, as shown in Figure 1.1. This shift of absorption bands toward the red end of the spectrum is known as redshift. Redshift is a shift in absorption bands toward the red end of the spectrum. What could make the absorption bands of a star shift toward the red? Redshift occurs when the light source is moving away from the observer or when the space between the observer and the source is stretched. What does it mean that stars and galaxies are redshifted? When astronomers see redshift in the light from a galaxy, they know that the galaxy is moving away from Earth. If galaxies were moving randomly, would some be redshifted but others be blueshifted? Of course. Since almost every galaxy in the universe has a redshift, almost every galaxy is moving away from Earth. Click image to the left or use the URL below. URL: "
"when edwin hubble measured the distance to other galaxies, he discovered that the galaxies",(A) Flickered on and off (B) Were moving toward us (C) Were stationary (D) Were moving away from us,D,"After discovering that there are galaxies beyond the Milky Way, Edwin Hubble went on to measure the distance to hundreds of other galaxies. His data would eventually show how the universe is changing, and would even yield clues as to how the universe formed. "
hubbles law states that:,(A) The farther away a galaxy is (B) the faster it is moving away from us (C) b The farther away a galaxy is (D) the slower it is moving away from us (E) c The closer a galaxy is (F) the faster it is moving away from us (G) d None of these,A,"Hubble measured the distances to galaxies. He also studied the motions of galaxies. In doing these things, Hubble noticed a relationship. This is now called Hubbles Law: The farther away a galaxy is, the faster it is moving away from us. There was only one conclusion he could draw from this. The universe is expanding! Figure 26.15 shows a simple diagram of the expanding universe. Imagine a balloon covered with tiny dots. When you blow up the balloon, the rubber stretches. The dots slowly move away from each other as the space between them increases. In an expanding universe, the space between galaxies is expanding. We see this as the other galaxies moving away from us. We also see that galaxies farther away from us move away faster than nearby galaxies. "
the universe is expanding in three-dimensions.,(A) True (B) False,A,"Edwin Hubble combined his measurements of the distances to galaxies with other astronomers measurements of redshift. From this data, he noticed a relationship, which is now called Hubbles Law: the farther away a galaxy is, the faster it is moving away from us. What could this mean about the universe? It means that the universe is expanding. Figure 1.2 shows a simplified diagram of the expansion of the universe. One way to picture this is to imagine a balloon covered with tiny dots to represent the galaxies. When you inflate the balloon, the dots slowly move away from each other because the rubber stretches in the space between them. If you were standing on one of the dots, you would see the other dots moving away from you. Also, the dots farther away from you on the balloon would move away faster than dots nearby. In this diagram of the expansion of the universe over time, the distance between galaxies gets bigger over time, although the size of each galaxy stays the same. An inflating balloon is only a rough analogy to the expanding universe for several reasons. One important reason is that the surface of a balloon has only two dimensions, while space has three dimensions. But space itself is stretching out between galaxies, just as the rubber stretches when a balloon is inflated. This stretching of space, which increases the distance between galaxies, is what causes the expansion of the universe. One other difference between the universe and a balloon involves the actual size of the galaxies. On a balloon, the dots will become larger in size as you inflate it. In the universe, the galaxies stay the same size; only the space between the galaxies increases. "
what is redshift?,(A) Sound waves are moving away from the observer (B) Absorption bands are shifted toward the red end of the spectrum (C) Absorption bands are shifted toward the blue end of the spectrum (D) All of the above,B,"If you look at a star through a prism, you will see a spectrum, or a range of colors through the rainbow. The spectrum will have specific dark bands where elements in the star absorb light of certain energies. By examining the arrangement of these dark absorption lines, astronomers can determine the composition of elements that make up a distant star. In fact, the element helium was first discovered in our Sun  not on Earth  by analyzing the absorption lines in the spectrum of the Sun. While studying the spectrum of light from distant galaxies, astronomers noticed something strange. The dark lines in the spectrum were in the patterns they expected, but they were shifted toward the red end of the spectrum, as shown in Figure 1.1. This shift of absorption bands toward the red end of the spectrum is known as redshift. Redshift is a shift in absorption bands toward the red end of the spectrum. What could make the absorption bands of a star shift toward the red? Redshift occurs when the light source is moving away from the observer or when the space between the observer and the source is stretched. What does it mean that stars and galaxies are redshifted? When astronomers see redshift in the light from a galaxy, they know that the galaxy is moving away from Earth. If galaxies were moving randomly, would some be redshifted but others be blueshifted? Of course. Since almost every galaxy in the universe has a redshift, almost every galaxy is moving away from Earth. Click image to the left or use the URL below. URL: "
astronomers determine the composition of a star by examining the dark absorption lines.,(A) True (B) False,A,"If you look at a star through a prism, you will see a spectrum, or a range of colors through the rainbow. The spectrum will have specific dark bands where elements in the star absorb light of certain energies. By examining the arrangement of these dark absorption lines, astronomers can determine the composition of elements that make up a distant star. In fact, the element helium was first discovered in our Sun  not on Earth  by analyzing the absorption lines in the spectrum of the Sun. While studying the spectrum of light from distant galaxies, astronomers noticed something strange. The dark lines in the spectrum were in the patterns they expected, but they were shifted toward the red end of the spectrum, as shown in Figure 1.1. This shift of absorption bands toward the red end of the spectrum is known as redshift. Redshift is a shift in absorption bands toward the red end of the spectrum. What could make the absorption bands of a star shift toward the red? Redshift occurs when the light source is moving away from the observer or when the space between the observer and the source is stretched. What does it mean that stars and galaxies are redshifted? When astronomers see redshift in the light from a galaxy, they know that the galaxy is moving away from Earth. If galaxies were moving randomly, would some be redshifted but others be blueshifted? Of course. Since almost every galaxy in the universe has a redshift, almost every galaxy is moving away from Earth. Click image to the left or use the URL below. URL: "
which example is true about the doppler effect?,(A) Dopper Effect is found only in sound waves (B) As an object moves toward you (C) the waves spread further apart (D) and vice versa (E) c As an object moves toward you (F) the waves pack closer together (G) and vice versa (H) d All of the above,C,"The Doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. (It can also occur when the sound source is stationary and the listener is moving.) The Figure 1.1 shows how the Doppler effect occurs. The sound waves from the police car siren travel outward in all directions. Because the car is racing forward (to the left), the sound waves get bunched up in front of the car and spread out behind it. Sound waves that are closer together have a higher frequency, and sound waves that are farther apart have a lower frequency. The frequency of sound waves, in turn, determines the pitch of the sound. Sound waves with a higher frequency produce sound with a higher pitch, and sound waves with a lower frequency produce sound with a lower pitch. "
"if a galaxy is moving closer to earth, it would have a blueshift.",(A) True (B) False,A,"Hubble measured the distances to galaxies. He also studied the motions of galaxies. In doing these things, Hubble noticed a relationship. This is now called Hubbles Law: The farther away a galaxy is, the faster it is moving away from us. There was only one conclusion he could draw from this. The universe is expanding! Figure 26.15 shows a simple diagram of the expanding universe. Imagine a balloon covered with tiny dots. When you blow up the balloon, the rubber stretches. The dots slowly move away from each other as the space between them increases. In an expanding universe, the space between galaxies is expanding. We see this as the other galaxies moving away from us. We also see that galaxies farther away from us move away faster than nearby galaxies. "
as the universe expands it is the __________ that is expanding.,(A) Space between the galaxies (B) Entire universe and everything in it (C) Space within the galaxies (D) Space within atoms and molecules,A,"Edwin Hubble combined his measurements of the distances to galaxies with other astronomers measurements of redshift. From this data, he noticed a relationship, which is now called Hubbles Law: the farther away a galaxy is, the faster it is moving away from us. What could this mean about the universe? It means that the universe is expanding. Figure 1.2 shows a simplified diagram of the expansion of the universe. One way to picture this is to imagine a balloon covered with tiny dots to represent the galaxies. When you inflate the balloon, the dots slowly move away from each other because the rubber stretches in the space between them. If you were standing on one of the dots, you would see the other dots moving away from you. Also, the dots farther away from you on the balloon would move away faster than dots nearby. In this diagram of the expansion of the universe over time, the distance between galaxies gets bigger over time, although the size of each galaxy stays the same. An inflating balloon is only a rough analogy to the expanding universe for several reasons. One important reason is that the surface of a balloon has only two dimensions, while space has three dimensions. But space itself is stretching out between galaxies, just as the rubber stretches when a balloon is inflated. This stretching of space, which increases the distance between galaxies, is what causes the expansion of the universe. One other difference between the universe and a balloon involves the actual size of the galaxies. On a balloon, the dots will become larger in size as you inflate it. In the universe, the galaxies stay the same size; only the space between the galaxies increases. "
"as the universe expands, the galaxies are also expanding.",(A) True (B) False,B,"Edwin Hubble combined his measurements of the distances to galaxies with other astronomers measurements of redshift. From this data, he noticed a relationship, which is now called Hubbles Law: the farther away a galaxy is, the faster it is moving away from us. What could this mean about the universe? It means that the universe is expanding. Figure 1.2 shows a simplified diagram of the expansion of the universe. One way to picture this is to imagine a balloon covered with tiny dots to represent the galaxies. When you inflate the balloon, the dots slowly move away from each other because the rubber stretches in the space between them. If you were standing on one of the dots, you would see the other dots moving away from you. Also, the dots farther away from you on the balloon would move away faster than dots nearby. In this diagram of the expansion of the universe over time, the distance between galaxies gets bigger over time, although the size of each galaxy stays the same. An inflating balloon is only a rough analogy to the expanding universe for several reasons. One important reason is that the surface of a balloon has only two dimensions, while space has three dimensions. But space itself is stretching out between galaxies, just as the rubber stretches when a balloon is inflated. This stretching of space, which increases the distance between galaxies, is what causes the expansion of the universe. One other difference between the universe and a balloon involves the actual size of the galaxies. On a balloon, the dots will become larger in size as you inflate it. In the universe, the galaxies stay the same size; only the space between the galaxies increases. "
"if a miner is standing on a fault, the __________ wall is where his safety helmet would be and the __________ wall is where his steel toed boots would be.",(A) Tail; head (B) Head; tail (C) Foot; hanging (D) Hanging; foot,D,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
"if there is no movement on either side of a fracture, the fracture is called this.",(A) A joint (B) A fault (C) A slip (D) A dip,A,"If there is no movement on either side of a fracture, the fracture is called a joint. The rocks below show horizontal and vertical jointing. These joints formed when the confining stress was removed from the rocks as shown in (Figure "
mountain ranges can uplift on these types of faults.,(A) Strike-slip faults (B) Reverse faults (C) Normal faults (D) Tensional faults,C,"Amazingly, even divergence can create mountain ranges. When tensional stresses pull crust apart, it breaks into blocks that slide up and drop down along normal faults. The result is alternating mountains and valleys, known as a basin-and-range (Figure 1.3). In basin-and-range, some blocks are uplifted to form ranges, known as horsts, and some are down-dropped to form basins, known as grabens. (a) Horsts and grabens. (b) Mountains in Nevada are of classic basin-and-range form. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
if the angle of a fault is inclined relative to the horizontal it is a,(A) Joint (B) Reverse Fault (C) Dip-slip Fault (D) Strike-slip Fault,C,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
horizontal-appearing layers can have a younger rock below an older rock if they are separated by a thrust fault.,(A) True (B) False,A,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
why wont california west of the san andreas fault fall into the pacific ocean?,(A) The motion along the fault is horizontal (B) The motion along the fault is thrust (C) That piece of land is being faulted upward (D) not downward (E) d There is too much friction,A,"The San Andreas Fault in California is a right-lateral strike-slip fault (Figure 7.15). It is also a transform fault because the San Andreas is a plate boundary. As you can see, California will not fall into the ocean someday. The land west of the San Andreas Fault is moving northeastward, while the North American plate moves southwest. Someday, millions of years from now, Los Angeles will be a suburb of San Francisco! "
strike slip faults result from __________ stresses.,(A) compressive (B) diagonal (C) tensional (D) shear,D,"A strike-slip fault is a dip-slip fault where the dip of the fault plane is vertical. Strike-slip faults result from shear stresses. If you stand with one foot on each side of a strike-slip fault, one side will be moving toward you while the other side moves away from you. If your right foot moves toward you, the fault is known as a right-lateral strike-slip fault. If your left foot moves toward you, the fault is a left-lateral strike-slip fault (Figure 7.14). "
this type of reverse fault has a plane angle that is nearly horizontal.,(A) Normal fault (B) Thrust fault (C) Strike-slip fault (D) Dip-slip fault,B,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
"at the san andreas fault, the pacific plate is moving north relative to the north american plate. this means that the san andreas is a",(A) Right-lateral strike-slip fault (B) Left-lateral strike-slip fault (C) Dip slip fault (D) Thrust fault,A,"The San Andreas Fault in California is a right-lateral strike-slip fault (Figure 7.15). It is also a transform fault because the San Andreas is a plate boundary. As you can see, California will not fall into the ocean someday. The land west of the San Andreas Fault is moving northeastward, while the North American plate moves southwest. Someday, millions of years from now, Los Angeles will be a suburb of San Francisco! "
"in a normal fault, the hanging wall goes up and the footwall goes down.",(A) True (B) False,B,"There are two types of dip-slip faults. In a normal fault, the hanging wall drops down relative to the footwall. In a reverse fault, the footwall drops down relative to the hanging wall. This diagram illustrates the two types of dip-slip faults: normal faults and reverse faults. Imagine miners extracting a re- source along a fault. The hanging wall is where miners would have hung their lanterns. The footwall is where they would have walked. A thrust fault is a type of reverse fault in which the fault plane angle is nearly horizontal. Rocks can slip many miles along thrust faults (Figure 1.4). At Chief Mountain in Montana, the upper rocks at the Lewis Overthrust are more than 1 billion years older than the lower rocks. How could this happen? Normal faults can be huge. They are responsible for uplifting mountain ranges in regions experiencing tensional stress. "
which of these can buffer flooding?,(A) Vegetation (B) Wetlands (C) Levees (D) All of the above,D,"Heavily vegetated lands are less likely to experience flooding. Plants slow down water as it runs over the land, giving it time to enter the ground. Even if the ground is too wet to absorb more water, plants still slow the waters passage and increase the time between rainfall and the waters arrival in a stream; this could keep all the water falling over a region from hitting the stream at once. Wetlands act as a buffer between land and high water levels and play a key role in minimizing the impacts of floods. Flooding is often more severe in areas that have been recently logged. "
a levee that protects the land near a river from flooding,(A) May cause there to be flooding upstream or downstream (B) May cause there to be flooding downstream only (C) May protect the entire river from flooding (D) Will keep that land safe from flooding as long as it is kept in working order,A,"People try to protect areas that might flood with dams, and dams are usually very effective. But high water levels sometimes cause a dam to break and then flooding can be catastrophic. People may also line a river bank with levees, high walls that keep the stream within its banks during floods. A levee in one location may just force the high water up or downstream and cause flooding there. The New Madrid Overflow in the Figure 1.2 was created with the recognition that the Mississippi River sometimes simply cannot be contained by levees and must be allowed to flood. "
a raised structure designed to hold back the waters of a stream or river in case of a flood.,(A) River (B) Levee (C) Dam (D) None of the above,C,"People try to protect areas that might flood with dams, and dams are usually very effective. But high water levels sometimes cause a dam to break and then flooding can be catastrophic. People may also line a river bank with levees, high walls that keep the stream within its banks during floods. A levee in one location may just force the high water up or downstream and cause flooding there. The New Madrid Overflow in the Figure 1.2 was created with the recognition that the Mississippi River sometimes simply cannot be contained by levees and must be allowed to flood. "
this river flooded sometimes causes extreme floods in the midwestern u.s.,(A) The Sacramento River (B) The Colorado River (C) The Des Moines River (D) The Mississippi River,D,"Floods usually occur when precipitation falls more quickly than water can be absorbed into the ground or carried away by rivers or streams. Waters may build up gradually over a period of weeks, when a long period of rainfall or snowmelt fills the ground with water and raises stream levels. Extremely heavy rains across the Midwestern U.S. in April 2011 led to flooding of the rivers in the Mississippi River basin in May 2011 (Figures 1.1 and 1.2). Click image to the left or use the URL below. URL:  This map shows the accumulated rainfall across the U.S. in the days from April 22 to April 29, 2011. Record flow in the Ohio and Mississippi Rivers has to go somewhere. Normal spring river levels are shown in 2010. The flooded region in the image from May 3, 2011 is the New Madrid Floodway, where overflow water is meant to go. 2011 is the first time since 1927 that this floodway was used. "
flooding is often worse when vegetation is cleared.,(A) True (B) False,A,"Heavily vegetated lands are less likely to experience flooding. Plants slow down water as it runs over the land, giving it time to enter the ground. Even if the ground is too wet to absorb more water, plants still slow the waters passage and increase the time between rainfall and the waters arrival in a stream; this could keep all the water falling over a region from hitting the stream at once. Wetlands act as a buffer between land and high water levels and play a key role in minimizing the impacts of floods. Flooding is often more severe in areas that have been recently logged. "
"floods are relatively recent phenomenon, only occurring since humans have altered the landscape.",(A) True (B) False,B,"A flood occurs when so much water enters a stream or river that it overflows its banks. Flood waters from a river are shown in Figure 13.10. Like this flood, many floods are caused by very heavy rains. Floods may also occur when deep snow melts quickly in the spring. Floods are a natural part of the water cycle, but they can cause a lot of damage. Farms and homes may be lost, and people may die. In 1939, millions of people died in a flood in China. Although freshwater is needed to grow crops and just to live, too much freshwater in the same place at once can be deadly. "
the lands downstream from a dam are safe from flooding.,(A) True (B) False,B,"People try to protect areas that might flood with dams, and dams are usually very effective. But high water levels sometimes cause a dam to break and then flooding can be catastrophic. People may also line a river bank with levees, high walls that keep the stream within its banks during floods. A levee in one location may just force the high water up or downstream and cause flooding there. The New Madrid Overflow in the Figure 1.2 was created with the recognition that the Mississippi River sometimes simply cannot be contained by levees and must be allowed to flood. "
plants reduce flooding by,(A) Keeping the rainwater from striking the ground (B) Slowing the raindrops down so they don’t all hit the ground at once (C) Allowing the water to flow downhill in its own way (D) All of these,B,"Heavily vegetated lands are less likely to experience flooding. Plants slow down water as it runs over the land, giving it time to enter the ground. Even if the ground is too wet to absorb more water, plants still slow the waters passage and increase the time between rainfall and the waters arrival in a stream; this could keep all the water falling over a region from hitting the stream at once. Wetlands act as a buffer between land and high water levels and play a key role in minimizing the impacts of floods. Flooding is often more severe in areas that have been recently logged. "
how did flooding of the nile river help the egyptians?,(A) Floodwaters were a source of nutrients along the floodplain (B) Flooding protected human settlements from invaders (C) Flooding moved sediment into the river delta and stopped large waves from coming ashore (D) All of these,A,"Within the floodplain of the Nile, soils are fertile enough for productive agriculture. Beyond this, infertile desert soils prevent viable farming. Not all the consequences of flooding are negative. Rivers deposit new nutrient-rich sediments when they flood, so floodplains have traditionally been good for farming. Flooding as a source of nutrients was important to Egyptians along the Nile River until the Aswan Dam was built in the 1960s. Although the dam protects crops and settlements from the annual floods, farmers must now use fertilizers to feed their cops. Floods are also responsible for moving large amounts of sediments about within streams. These sediments provide habitats for animals, and the periodic movement of sediment is crucial to the lives of several types of organisms. Plants and fish along the Colorado River, for example, depend on seasonal flooding to rearrange sand bars. "
rocks that deform plastically under compressive stresses crumple into this.,(A) Plateaus (B) Calderas (C) Folds (D) Valleys,C,"Rocks deforming plastically under compressive stresses crumple into folds. They do not return to their original shape. If the rocks experience more stress, they may undergo more folding or even fracture. You can see three types of folds. "
this type of stress creates folds.,(A) Tension (B) Shearing (C) Compression (D) No stress,C,"Rocks deforming plastically under compressive stresses crumple into folds. They do not return to their original shape. If the rocks experience more stress, they may undergo more folding or even fracture. You can see three types of folds. "
an anticline in three dimensions is a basin.,(A) True (B) False,B,"A syncline is a fold that bends downward. The youngest rocks are at the center and the oldest are at the outside (Figure 1.3). When rocks bend downward in a circular structure, that structure is called a basin (Figure 1.4). If the rocks are exposed at the surface, where are the oldest rocks located? Click image to the left or use the URL below. URL:  Anticlines are formations that have folded rocks upward. (a) Schematic of a syncline. (b) This syncline is in Rainbow Basin, California. Some folding can be fairly complicated. What do you see in the photo above? "
a monocline,(A) Is a tilted rock layer that is no longer horizontal (B) Could be the limb of a syncline (C) Could be the limb of an anticline (D) All of the above,D,"A monocline is a simple bend in the rock layers so that they are no longer horizontal (see Figure 1.1 for an example). At Utahs Cockscomb, the rocks plunge downward in a monocline. What you see in the image appears to be a monocline. Are you certain it is a monocline? What else might it be? What would you have to do to figure it out? "
a dome is a structure made when rocks arch upward.,(A) True (B) False,A,"Anticline: An anticline is a fold that arches upward. The rocks dip away from the center of the fold (Figure 1.2). The oldest rocks are at the center of an anticline and the youngest are draped over them. When rocks arch upward to form a circular structure, that structure is called a dome. If the top of the dome is sliced off, where are the oldest rocks located? "
"if a dome is eroded away, what are the ages of the rocks from inside to outside.",(A) Youngest in the inside; oldest in the outside (B) Oldest in the inside; youngest in the outside (C) Rocks are the same age through the dome (D) Some old rocks are inside and some are outside,B,"By combining magnetic polarity data from rocks on land and on the seafloor with radiometric age dating and fossil ages, scientists came up with a time scale for the magnetic reversals. The first four magnetic periods are: Brunhes normal - present to 730,000 years ago. Matuyama reverse - 730,000 years ago to 2.48 million years ago. Gauss normal - 2.48 to 3.4 million years ago. Gilbert reverse - 3.4 to 5.3 million years ago. The scientists noticed that the rocks got older with distance from the mid-ocean ridges. The youngest rocks were located at the ridge crest and the oldest rocks were located the farthest away, abutting continents. Scientists also noticed that the characteristics of the rocks and sediments changed with distance from the ridge axis as seen in the Table 1.1. Rock ages At ridge axis With distance from axis youngest becomes older Sediment thickness none becomes thicker Crust thickness Heat flow thinnest becomes thicker hottest becomes cooler Away from the ridge crest, sediment becomes older and thicker, and the seafloor becomes thicker. Heat flow, which indicates the warmth of a region, is highest at the ridge crest. The oldest seafloor is near the edges of continents or deep sea trenches and is less than 180 million years old (Figure something was happening to the older seafloor. Seafloor is youngest at the mid-ocean ridges and becomes progressively older with distance from the ridge. How can you explain the observations that scientists have made in the oceans? Why is rock younger at the ridge and oldest at the farthest points from the ridge? The scientists suggested that seafloor was being created at the ridge. Since the planet is not getting larger, they suggested that it is destroyed in a relatively short amount of geologic time. Click image to the left or use the URL below. URL: "
an anticline has rocks that bend.,(A) Downward (B) Diagonally (C) Vertically (D) Upward,D,"Anticline: An anticline is a fold that arches upward. The rocks dip away from the center of the fold (Figure 1.2). The oldest rocks are at the center of an anticline and the youngest are draped over them. When rocks arch upward to form a circular structure, that structure is called a dome. If the top of the dome is sliced off, where are the oldest rocks located? "
the michigan basin is made by rock bending,(A) Downward (B) Diagonally (C) Vertically (D) Upward,A,"Amazingly, even divergence can create mountain ranges. When tensional stresses pull crust apart, it breaks into blocks that slide up and drop down along normal faults. The result is alternating mountains and valleys, known as a basin-and-range (Figure 1.3). In basin-and-range, some blocks are uplifted to form ranges, known as horsts, and some are down-dropped to form basins, known as grabens. (a) Horsts and grabens. (b) Mountains in Nevada are of classic basin-and-range form. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
"when rocks are bent into a fold, they may go back to their original shape if the stress is released.",(A) True (B) False,B,"Rocks deforming plastically under compressive stresses crumple into folds. They do not return to their original shape. If the rocks experience more stress, they may undergo more folding or even fracture. You can see three types of folds. "
"in a syncline, the youngest rocks are outside and the oldest rocks are in the center.",(A) True (B) False,B,"A syncline is a fold that bends downward. The youngest rocks are at the center and the oldest are at the outside (Figure 1.3). When rocks bend downward in a circular structure, that structure is called a basin (Figure 1.4). If the rocks are exposed at the surface, where are the oldest rocks located? Click image to the left or use the URL below. URL:  Anticlines are formations that have folded rocks upward. (a) Schematic of a syncline. (b) This syncline is in Rainbow Basin, California. Some folding can be fairly complicated. What do you see in the photo above? "
earth formed,(A) At the same time as the other planets (B) About 500 million years later than the sun (C) At the same time as the moon (D) All of the above,A,"Earth came together (accreted) from the cloud of dust and gas known as the solar nebula nearly 4.6 billion years ago, the same time the Sun and the rest of the solar system formed. Gravity caused small bodies of rock and metal orbiting the proto-Sun to smash together to create larger bodies. Over time, the planetoids got larger and larger until they became planets. "
scientists think that meteorite bombardment was extremely common on the early earth because,(A) The outer planets have lots of impact craters (B) Earth has lots of ancient impact craters (C) The Moon has lots of ancient impact craters (D) All of the above,C,"Although most meteors burn up in the atmosphere, larger meteoroids may strike the Earths surface to create a meteorite. Meteorites are valuable to scientists because they provide clues about our solar system. Many meteorites are from asteroids that formed when the solar system formed (Figure 1.2). A few meteorites are made of rocky material that is thought to have come from Mars when an asteroid impact shot material off the Martian surface and into space. Click image to the left or use the URL below. URL: "
"due to gravity, planetoids got larger and larger until they became planets.",(A) True (B) False,A,"Earth came together (accreted) from the cloud of dust and gas known as the solar nebula nearly 4.6 billion years ago, the same time the Sun and the rest of the solar system formed. Gravity caused small bodies of rock and metal orbiting the proto-Sun to smash together to create larger bodies. Over time, the planetoids got larger and larger until they became planets. "
which is not a reason why earth was molten in its early days?,(A) Gravitational contraction (B) Radioactive decay (C) The sun (D) Bombardment by asteroids,C,"When Earth formed 4.6 billion years ago, it would not have been called the water planet. There were no oceans then. In fact, there was no liquid water at all. Early Earth was too hot for liquid water to exist. Earths early years were spent as molten rock and metal. "
there was more radioactive decay early in earth history than now because many radioactive elements have long half lives.,(A) True (B) False,B,"Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). "
differentiation,(A) Caused Earth to have a metal core (B) Took place when Earth was molten (C) Allowed lighter elements to rise to the surface (D) All of these,D,"When Earth was entirely molten, gravity drew denser elements to the center and lighter elements rose to the surface. The separation of Earth into layers based on density is known as differentiation. The densest material moved to the center to create the planets dense metallic core. Materials that are intermediate in density became part of the mantle (Figure 1.1). "
earths first crust probably,(A) Was made of light minerals (B) like the Moon’s (C) b Recycled into the mantle due to vigorous convection (D) c Resembled modern continental crust (E) d All of these,B,"The earliest crust was probably basalt. It may have resembled the current seafloor. This crust formed before there were any oceans. More than 4 billion years ago, continental crust appeared. The first continents were very small compared with those today. "
what material helps scientists describe the geologic composition of early earth?,(A) Zircon crystals (B) Meteorites (C) Lunar rocks (D) All of the above,D,"There is not much material to let us know about the earliest days of our planet Earth. What there is comes from three sources: (1) zircon crystals, the oldest materials found on Earth, which show that the age of the earliest crust formed at least 4.4 billion years ago; (2) meteorites that date from the beginning of the solar system, to nearly 4.6 billion years ago (Figure 1.2); and (3) lunar rocks, which represent the early days of the Earth-Moon system as far back as 4.5 billion years ago. "
the oldest materials geologists found on earth thus far are,(A) Zircon crystals in ancient rocks (B) Diamonds from kimberlite pipes (C) Exposed gabbro in the oceanic crust (D) Cooled metal fragments from the core,A,"There is not much material to let us know about the earliest days of our planet Earth. What there is comes from three sources: (1) zircon crystals, the oldest materials found on Earth, which show that the age of the earliest crust formed at least 4.4 billion years ago; (2) meteorites that date from the beginning of the solar system, to nearly 4.6 billion years ago (Figure 1.2); and (3) lunar rocks, which represent the early days of the Earth-Moon system as far back as 4.5 billion years ago. "
gravity releases energy when material is squeezed so hard that the pressure swells.,(A) True (B) False,A,"Gravity is a force, but not like other forces you may know. Gravity is a bit special. You know that a force is a push or pull. If you push a ball, it starts to roll. If you lift a book, it moves upward. Now, imagine you drop a ball. It falls to the ground. Can you see the force pulling it down? That is what makes gravity really cool. It is invisible. Invisible means you cannot see it. But wait, it has even more surprises. Gravity holds planets in place around the Sun. Gravity keeps the Moon from flying off into space. Gravity exerts a force on objects that are not even touching. In fact, gravity can act over very large distances. However, the force does get weaker the farther apart the objects are. "
apollo astronauts brought back a rock from the moon that is,(A) Unknown and unknowable (B) The same age as the formation of the solar system (C) 100 million years younger than the formation of the solar system (D) 1 billion years older than the formation of the solar system,C,"Lunar rocks reveal an enormous amount about Earths early days. The Genesis Rock, with a date of 4.5 billion years, is only about 100 million years younger than the solar system (see opening image). The rock is a piece of the Moons anorthosite crust, which was the original crust. Why do you think Moon rocks contain information that is not available from Earths own materials? Can you find how all of the evidence presented in the bullet points above is present in the Moons birth story? "
the size of the moon is comparable to the planet ___________.,(A) Jupiter (B) Mercury (C) Mars (D) Saturn,B,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
the moon is similar in composition as the planet,(A) Earth (B) Mars (C) Uranus (D) Neptune,A,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
the story of how the moon formed had to account for,(A) Carbon isotope ratios indicating that Earth and Moon formed in the same part of the solar system (B) The similar size of Earth and Moon’s cores (C) Earth’s faster than expected spin (D) All of these,C,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
the moon formed at the same time earth formed.,(A) True (B) False,B,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
the ________ ratios of moon and earth indicate that they originated in the same part of the solar system.,(A) Hydrogen Isotope (B) Oxygen Isotope (C) Neon Isotope (D) Dust,B,"To determine how the Moon formed, scientists had to account for several lines of evidence: The Moon is large; not much smaller than the smallest planet, Mercury. Earth and Moon are very similar in composition. Moons surface is 4.5 billion years old, about the same as the age of the solar system. For a body its size and distance from the Sun, the Moon has very little core; Earth has a fairly large core. The oxygen isotope ratios of Earth and Moon indicate that they originated in the same part of the solar system. Earth has a faster spin than it should have for a planet of its size and distance from the Sun. Can you devise a birth story for the Moon that takes all of these bits of data into account? "
moons story began when,(A) A tremendous number of asteroids hit Earth (B) The Sun flung material out into this part of space (C) Earth split into two equal bodies (D) A Mars-sized asteroid hit Earth,D,"Astronomers have carried out computer simulations that are consistent with these facts and have detailed a birth story for the Moon. A little more than 4.5 billion years ago, roughly 70 million years after Earth formed, planetary bodies were being pummeled by asteroids and planetoids of all kinds. Earth was struck by a Mars-sized asteroid (Figure 1.1). An artists depiction of the impact that produced the Moon. The tremendous energy from the impact melted both bodies. The molten material mixed up. The dense metals remained on Earth but some of the molten, rocky material was flung into an orbit around Earth. It eventually accreted into a single body, the Moon. Since both planetary bodies were molten, material could differentiate out of the magma ocean into core, mantle, and crust as they cooled. Earths fast spin is from energy imparted to it by the impact. "
the material that came together to form the moon was flung into space from,(A) Earth (B) The Sun (C) Jupiter (D) None of these,A,"Astronomers have carried out computer simulations that are consistent with these facts and have detailed a birth story for the Moon. A little more than 4.5 billion years ago, roughly 70 million years after Earth formed, planetary bodies were being pummeled by asteroids and planetoids of all kinds. Earth was struck by a Mars-sized asteroid (Figure 1.1). An artists depiction of the impact that produced the Moon. The tremendous energy from the impact melted both bodies. The molten material mixed up. The dense metals remained on Earth but some of the molten, rocky material was flung into an orbit around Earth. It eventually accreted into a single body, the Moon. Since both planetary bodies were molten, material could differentiate out of the magma ocean into core, mantle, and crust as they cooled. Earths fast spin is from energy imparted to it by the impact. "
the genesis rock is a piece of the moons original crust.,(A) True (B) False,A,"Lunar rocks reveal an enormous amount about Earths early days. The Genesis Rock, with a date of 4.5 billion years, is only about 100 million years younger than the solar system (see opening image). The rock is a piece of the Moons anorthosite crust, which was the original crust. Why do you think Moon rocks contain information that is not available from Earths own materials? Can you find how all of the evidence presented in the bullet points above is present in the Moons birth story? "
"in the early solar system, there was a lot of debris  asteroids, comets and planetoids - flying around.",(A) True (B) False,A,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
the solar system formed nearly _________ years ago,(A) 100 billion (B) 5 million (C) 5 billion (D) 3 thousand,C,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
the major bodies of the solar system formed,(A) At the same time (B) In this order: sun (C) inner planets (D) outer planets (E) asteroids (F) comets (G) c In this order: asteroids (H) comets (I) sun (J) outer planets (K) inner planets (L) d From a black hole,B,"The Sun was the first object to form in the solar system. Gravity pulled matter together to the center of the disk. Density and pressure increased tremendously. Nuclear fusion reactions begin. In these reactions, the nuclei of atoms come together to form new, heavier chemical elements. Fusion reactions release huge amounts of nuclear energy. From these reactions a star was born, the Sun. Meanwhile, the outer parts of the disk were cooling off. Small pieces of dust started clumping together. These clumps collided and combined with other clumps. Larger clumps attracted smaller clumps with their gravity. Eventually, all these pieces grew into the planets and moons that we find in our solar system today. The outer planets Jupiter, Saturn, Uranus, and Neptune condensed from lighter materials. Hydrogen, helium, water, ammonia, and methane were among them. Its so cold by Jupiter and beyond that these materials can form solid particles. Closer to the Sun, they are gases. Since the gases can escape, the inner planets Mercury, Venus, Earth, and Mars formed from denser elements. These elements are solid even when close to the Sun. "
a nebula is,(A) A newly formed star (B) The material that was left over from the Big Bang (C) A giant cloud of dust and gas (D) None of these,C,"Stars are born in clouds of gas and dust called nebulas. Our Sun and solar system formed out of a nebula. A nebula is shown in Figure 26.2. In Figure 26.1, the fuzzy area beneath the central three stars contains the Orion nebula. For a star to form, gravity pulls gas and dust into the center of the nebula. As the material becomes denser, the pressure and the temperature increase. When the temperature of the center becomes hot enough, nuclear fusion begins. The ball of gas has become a star! "
"the nebular was drawn together by gravity, which released kinetic energy.",(A) True (B) False,B,"The most widely accepted explanation of how the solar system formed is called the nebular hypothesis. According to this hypothesis, the Sun and the planets of our solar system formed about 4.6 billion years ago from the collapse of a giant cloud of gas and dust, called a nebula. The nebula was drawn together by gravity, which released gravitational potential energy. As small particles of dust and gas smashed together to create larger ones, they released kinetic energy. As the nebula collapsed, the gravity at the center increased and the cloud started to spin because of its angular momentum. As it collapsed further, the spinning got faster, much as an ice skater spins faster when he pulls his arms to his sides during a spin. Much of the clouds mass migrated to its center but the rest of the material flattened out in an enormous disk. The disk contained hydrogen and helium, along with heavier elements and even simple organic molecules. "
the sun formed in the center of the nebula because,(A) Most of the cloud’s mass migrated to the center (B) The density at the center was extreme (C) Hydrogen and helium were present and nuclear fusion began (D) All of these,D,"The Sun and planets formed from a giant cloud of gas and dust. This was the solar nebula. The cloud contracted and began to spin. As it contracted, its temperature and pressure increased. The cloud spun faster, and formed into a disk. Scientists think the solar system at that time looked like these disk-shaped objects in the Orion Nebula (Figure "
the planets formed because,(A) Clumps of material continued to collide due to gravity (B) The burning sun flung molten material off into orbit (C) Solid material precipitated out of the gases that orbited the sun (D) None of these,A,"As gravity pulled matter into the center of the disk, the density and pressure at the center became intense. When the pressure in the center of the disk was high enough, nuclear fusion began. A star was bornthe Sun. The burning star stopped the disk from collapsing further. Meanwhile, the outer parts of the disk were cooling off. Matter condensed from the cloud and small pieces of dust started clumping together. These clumps collided and combined with other clumps. Larger clumps, called An artists painting of a protoplanetary disk. planetesimals, attracted smaller clumps with their gravity. Gravity at the center of the disk attracted heavier particles, such as rock and metal and lighter particles remained further out in the disk. Eventually, the planetesimals formed protoplanets, which grew to become the planets and moons that we find in our solar system today. Because of the gravitational sorting of material, the inner planets  Mercury, Venus, Earth, and Mars  formed from dense rock and metal. The outer planets  Jupiter, Saturn, Uranus and Neptune  condensed farther from the Sun from lighter materials such as hydrogen, helium, water, ammonia, and methane. Out by Jupiter and beyond, where its very cold, these materials form solid particles. The nebular hypothesis was designed to explain some of the basic features of the solar system: The orbits of the planets lie in nearly the same plane with the Sun at the center The planets revolve in the same direction The planets mostly rotate in the same direction The axes of rotation of the planets are mostly nearly perpendicular to the orbital plane The oldest moon rocks are 4.5 billion years Click image to the left or use the URL below. URL: "
the planets are sorted by density outward from the sun because of,(A) Centrifugal force (B) Angular momentum (C) The planetary orbits (D) Gravity,D,"As gravity pulled matter into the center of the disk, the density and pressure at the center became intense. When the pressure in the center of the disk was high enough, nuclear fusion began. A star was bornthe Sun. The burning star stopped the disk from collapsing further. Meanwhile, the outer parts of the disk were cooling off. Matter condensed from the cloud and small pieces of dust started clumping together. These clumps collided and combined with other clumps. Larger clumps, called An artists painting of a protoplanetary disk. planetesimals, attracted smaller clumps with their gravity. Gravity at the center of the disk attracted heavier particles, such as rock and metal and lighter particles remained further out in the disk. Eventually, the planetesimals formed protoplanets, which grew to become the planets and moons that we find in our solar system today. Because of the gravitational sorting of material, the inner planets  Mercury, Venus, Earth, and Mars  formed from dense rock and metal. The outer planets  Jupiter, Saturn, Uranus and Neptune  condensed farther from the Sun from lighter materials such as hydrogen, helium, water, ammonia, and methane. Out by Jupiter and beyond, where its very cold, these materials form solid particles. The nebular hypothesis was designed to explain some of the basic features of the solar system: The orbits of the planets lie in nearly the same plane with the Sun at the center The planets revolve in the same direction The planets mostly rotate in the same direction The axes of rotation of the planets are mostly nearly perpendicular to the orbital plane The oldest moon rocks are 4.5 billion years Click image to the left or use the URL below. URL: "
the inner planets are made primarily of,(A) Dense rock and metal (B) Gases and ices (C) Hydrogen (D) helium (E) water (F) ammonia and methane (G) d All of the above,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
the nebular hypothesis explains why,(A) The planets orbit the sun in different planes (B) The oldest rocks scientists have dated are about the same age (C) Half the planets revolve clockwise and half the opposite (D) All of these,B,"The most widely accepted explanation of how the solar system formed is called the nebular hypothesis. According to this hypothesis, the Sun and the planets of our solar system formed about 4.6 billion years ago from the collapse of a giant cloud of gas and dust, called a nebula. The nebula was drawn together by gravity, which released gravitational potential energy. As small particles of dust and gas smashed together to create larger ones, they released kinetic energy. As the nebula collapsed, the gravity at the center increased and the cloud started to spin because of its angular momentum. As it collapsed further, the spinning got faster, much as an ice skater spins faster when he pulls his arms to his sides during a spin. Much of the clouds mass migrated to its center but the rest of the material flattened out in an enormous disk. The disk contained hydrogen and helium, along with heavier elements and even simple organic molecules. "
materials that on earth are liquids or gases are solids in the outer planets.,(A) True (B) False,A,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
fossil fuels are compounds of _________________.,(A) Nitrogen and carbon (B) Nitrogen and hydrogen (C) Carbon and Hydrogen (D) Calcium and Nitrogen,C,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
hydrocarbons in solid form are called _________________.,(A) Coal (B) Petroleum (C) Crude oil (D) Natural gas,A,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
hydrocarbons in gas form are called __________________.,(A) Coal (B) Petroleum (C) Natural gas (D) Crude oil,C,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
how do fossil fuels form?,(A) Biological remains are buried beneath masses of sediment and exposed to high heat and (B) Dinosaurs are buried in hot tar (C) adding their bodies to the mass of fossil fuel (D) c Plants die in swamps and their bodies are converted to fossil fuels (E) d None of these,A,"Can you name some fossils? How about dinosaur bones or dinosaur footprints? Animal skeletons, teeth, shells, coprolites (otherwise known as feces), or any other remains or traces from a living creature that becomes rock is a fossil. The same processes that formed these fossils also created some of our most important energy resources, fossil fuels. Coal, oil, and natural gas are fossil fuels. Fossil fuels come from living matter starting about 500 million years ago. Millions of years ago, plants used energy from the Sun to form sugars, carbohydrates, and other energy-rich carbon compounds. As plants and animals died, their remains settled on the ground on land and in swamps, lakes, and seas (Figure 1.1). Over time, layer upon layer of these remains accumulated. Eventually, the layers were buried so deeply that they were crushed by an enormous mass of earth. The weight of this earth pressing down on these plant and animal remains created intense heat and pressure. After millions of years of heat and pressure, the material in these layers turned into chemicals called hydrocarbons (Figure 1.2). Hydrocarbons are made of carbon and hydrogen atoms. This molecule with one carbon and four hydrogen atoms is methane. Hydrocarbons can be solid, liquid, or gaseous. The solid form is what we know as coal. The liquid form is petroleum, or crude oil. Natural gas is the gaseous form. The solar energy stored in fossil fuels is a rich source of energy. Although fossil fuels provide very high quality energy, they are non-renewable. Click image to the left or use the URL below. URL: "
what is the original source of energy for fossil fuels?,(A) The sun (B) Heat from the core (C) Heat from burial by sediments (D) Food for the animals,A,"Can you name some fossils? How about dinosaur bones or dinosaur footprints? Animal skeletons, teeth, shells, coprolites (otherwise known as feces), or any other remains or traces from a living creature that becomes rock is a fossil. The same processes that formed these fossils also created some of our most important energy resources, fossil fuels. Coal, oil, and natural gas are fossil fuels. Fossil fuels come from living matter starting about 500 million years ago. Millions of years ago, plants used energy from the Sun to form sugars, carbohydrates, and other energy-rich carbon compounds. As plants and animals died, their remains settled on the ground on land and in swamps, lakes, and seas (Figure 1.1). Over time, layer upon layer of these remains accumulated. Eventually, the layers were buried so deeply that they were crushed by an enormous mass of earth. The weight of this earth pressing down on these plant and animal remains created intense heat and pressure. After millions of years of heat and pressure, the material in these layers turned into chemicals called hydrocarbons (Figure 1.2). Hydrocarbons are made of carbon and hydrogen atoms. This molecule with one carbon and four hydrogen atoms is methane. Hydrocarbons can be solid, liquid, or gaseous. The solid form is what we know as coal. The liquid form is petroleum, or crude oil. Natural gas is the gaseous form. The solar energy stored in fossil fuels is a rich source of energy. Although fossil fuels provide very high quality energy, they are non-renewable. Click image to the left or use the URL below. URL: "
plants use solar energy to create,(A) New plants (B) Larger bodies (C) Carbon compounds (D) All of the above,D,"Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. "
methane is a molecule made with one carbon and _____ hydrogen atoms.,(A) One (B) Two (C) Three (D) Four,D,"A carbon atom can form covalent bonds with other carbon atoms or with the atoms of other elements. Carbon often forms bonds with hydrogen. Compounds that contain only carbon and hydrogen are called hydrocarbons. Methane (CH4 ), which is modeled in the Figure 1.2, is an example of a hydrocarbon. In methane, a single carbon atom forms covalent bonds with four hydrogen atoms. The diagram on the left in the Figure 1.2 shows all the shared valence electrons. The diagram on the right in the Figure 1.2, called a structural formula, represents each pair of shared electrons with a dash (-). Methane (CH4 ) "
fossil fuels are a very poor source of energy.,(A) True (B) False,B,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
what is the biggest downside our dependence on fossil fuels for energy?,(A) They are found almost everywhere (B) They are non-renewable (C) They are extremely expensive (D) They are found below ground,B,"Fossil fuels present many problems. These fuels are non-renewable resources, so our supplies of them will eventually run out. Safety can be a problem, too. Since these fuels burn so easily, a natural gas leak in a building or an underground pipe can lead to a deadly explosion. Using fossil fuels affects the environment in a variety of ways. There are impacts to the environment when we extract these resources. Burning these fuels causes air pollution. These fuels release carbon dioxide, which is a major factor in global warming (Figure 5.5). Many of the problems with fossil fuels are worse for coal than for oil or natural gas. Burning coal releases more carbon dioxide than either oil or natural gas. Yet coal is the most common fossil fuel, so we continue to burn large amounts of it. That makes coal the biggest contributor to global warming. Another problem with coal is that most coal contains sulfur. As it burns, the sulfur goes into the air as sulfur dioxide. Sulfur dioxide is the main cause of acid rain. Acid rain can be deadly to plants, animals, and whole ecosystems. Burning coal also puts a large number of small solid particulates into the air. These particles are dangerous to people, especially those who have asthma. People with asthma may end up in the hospital on days when particulate pollution is high. "
most of the fossil fuels we use today formed hundreds of millions of years ago.,(A) True (B) False,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
"being nonrenewable resources, fossil fuels will last on the order of decades for coal and centuries for oil and natural gas.",(A) True (B) False,B,"A nonrenewable resource is a natural resource that is consumed or used up faster than it can be made by nature. Two main types of nonrenewable resources are fossil fuels and nuclear power. Fossil fuels, such as petroleum, coal, and natural gas, formed from plant and animal remains over periods from 50 to 350 million years ago. They took millions of years to form. Humans have been consuming fossil fuels for less than 200 years, yet remaining reserves of oil can supply our needs only until around the year 2055. Natural gas can only supply us until around 2085. Coal will last longer, until around the year 2250. That is why it is so important to develop alternate forms of energy, especially for our cars. Today, electric cars are becoming more and more common. Considering the year 2055 is not that far away, what would happen if we ran out of gasoline? Alternative use of energy, especially in transportation, must become a standard feature of all cars and trucks and planes by the middle of the century. Nuclear power is the use of nuclear energy ( nuclear fission) to create energy inside of a nuclear reactor ( Figure uranium fuel supplies, which will last to about the year 2100 (or longer) at current rates of use. However, new technologies could make some uranium fuel reserves more useful. Population growth, especially in developing countries, should make people think about how fast they are consuming resources. Governments around the world should seriously consider these issues. Developing nations will also increase demands on natural resources as they build more factories ( Figure 1.2). Improvements in technology, conservation of resources, and controls in population growth could all help to decrease the demand on natural resources. Aerial photo of the Bruce Nuclear Gener- ating Station near Kincardine, Ontario. Per capita energy consumption (2003) shows the unequal distribution of wealth, technology, and energy use. "
oil from shale is different from oil from petroleum because it is,(A) Much purer (B) Very easy to extract and refine (C) Is collected in shale reservoirs (D) Is dispersed through rock,D,"As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited (Figure 1.2). These include oil shale and tar sands. Oil shale is rock that contains dispersed oil that has not collected in reservoirs. To extract the oil from the shale requires enormous amounts of hot water. Tar sands are rocky materials mixed with very thick oil. The tar is too thick to pump and so tar sands are strip-mined. Hot water and caustic soda are used to separate the oil from the rock. The environmental consequences of mining these fuels, and of fossil fuel use in general, along with the fact that these fuels do not have a limitless supply, are prompting the development of alternative energy sources in some regions. Click image to the left or use the URL below. URL:  A satellite image of an oil-sands mine in Canada. Click image to the left or use the URL below. URL: "
"although petroleum, coal and natural gas will eventually run out, tar sands and oil shale will be available for centuries at no more cost than traditional sources of fossil fuels.",(A) True (B) False,B,"As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited (Figure 1.2). These include oil shale and tar sands. Oil shale is rock that contains dispersed oil that has not collected in reservoirs. To extract the oil from the shale requires enormous amounts of hot water. Tar sands are rocky materials mixed with very thick oil. The tar is too thick to pump and so tar sands are strip-mined. Hot water and caustic soda are used to separate the oil from the rock. The environmental consequences of mining these fuels, and of fossil fuel use in general, along with the fact that these fuels do not have a limitless supply, are prompting the development of alternative energy sources in some regions. Click image to the left or use the URL below. URL:  A satellite image of an oil-sands mine in Canada. Click image to the left or use the URL below. URL: "
if people everyone in the developed world froze their use of oil at its current level the annual amount of oil used would not increase.,(A) True (B) False,B,"People in the richer nations of the world use far more energy, especially energy from fossil fuels, than people in the poorer nations do. Figure 17.23 compares the amounts of oil used by the top ten oil-consuming nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels a year. Because richer nations use more fossil fuels, they also cause more air pollution and global warming than poorer nations do. "
much of the concern about the dangers of fracking is due to,(A) The distance the oil must travel from where it is obtained to where it is used (B) The chemicals that are in the fracking fluids (C) The amount of rock disturbed at the land surface (D) All of the above,B,"Natural gas burns much cleaner than other fossil fuels, meaning that it causes less air pollution. Natural gas also produces less carbon dioxide than other fossil fuels do for the same amount of energy, so its global warming effects are less (Figure 1.2). Unfortunately, drilling for natural gas can be environmentally destructive. One technique used is hydraulic fractur- ing, also called fracking, which increases the rate of recovery of natural gas. Fluids are pumped through a borehole to create fractures in the reservoir rock that contains the natural gas. Material is added to the fluid to prevent the fractures from closing. The damage comes primarily from chemicals in the fracturing fluids. Chemicals that have been found in the fluids may be carcinogens (cancer-causing), radioactive materials, or endocrine disruptors, which interrupt hormones in the bodies of humans and animals. The fluids may get into groundwater or may runoff into streams and other surface waters. As noted above, fracking may cause earthquakes. Click image to the left or use the URL below. URL: "
_________ are rocky materials mixed with very thick oil.,(A) Oil shales (B) Tar pits (C) Conglomerates (D) Tar sands,D,"Oil from the ground is called crude oil, which is a mixture of many different hydrocarbons. Crude oil is a thick dark brown or black liquid hydrocarbon. Oil also forms from buried dead organisms, but these are tiny organisms that live on the sea surface and then sink to the seafloor when they die. The dead organisms are kept away from oxygen by layers of other dead creatures and sediments. As the layers pile up, heat and pressure increase. Over millions of years, the dead organisms turn into liquid oil. "
"as of today, fossil fuel provides about ______ of the worlds energy.",(A) 50% (B) 65% (C) 85% (D) 100%,C,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
what is a reason tar sands are strip-mined rather than pumped?,(A) Tar sands are too thick to pump (B) Tar sands are solid and cannot flow (C) Tar sands are too watered down to pump (D) None of the above,A,"As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited (Figure 1.2). These include oil shale and tar sands. Oil shale is rock that contains dispersed oil that has not collected in reservoirs. To extract the oil from the shale requires enormous amounts of hot water. Tar sands are rocky materials mixed with very thick oil. The tar is too thick to pump and so tar sands are strip-mined. Hot water and caustic soda are used to separate the oil from the rock. The environmental consequences of mining these fuels, and of fossil fuel use in general, along with the fact that these fuels do not have a limitless supply, are prompting the development of alternative energy sources in some regions. Click image to the left or use the URL below. URL:  A satellite image of an oil-sands mine in Canada. Click image to the left or use the URL below. URL: "
the keystone xl pipeline is controversial because the oil it carries could cause environmental damage.,(A) True (B) False added,A,"Processing natural gas has harmful effects on the environment, just like oil. Natural gas burns cleaner than other fossil fuels. As a result, it causes less air pollution. It also produces less carbon dioxide than the other fossil fuels. Still, natural gas does emit pollutants. "
the environmental consequences of obtaining energy from tar sands include,(A) Pumping the sands in pipelines that go for thousands of miles (B) Freezing the sands so that they can be mined as solids (C) which uses energy (D) c Using a lot of water that must be heated (E) plus caustic chemicals (F) d None of the above,C,"As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited (Figure 1.2). These include oil shale and tar sands. Oil shale is rock that contains dispersed oil that has not collected in reservoirs. To extract the oil from the shale requires enormous amounts of hot water. Tar sands are rocky materials mixed with very thick oil. The tar is too thick to pump and so tar sands are strip-mined. Hot water and caustic soda are used to separate the oil from the rock. The environmental consequences of mining these fuels, and of fossil fuel use in general, along with the fact that these fuels do not have a limitless supply, are prompting the development of alternative energy sources in some regions. Click image to the left or use the URL below. URL:  A satellite image of an oil-sands mine in Canada. Click image to the left or use the URL below. URL: "
"freshwater ecosystems include lakes, ponds, streams and wetlands.",(A) True (B) False,A,"Organisms that live in lakes, ponds, streams, springs or wetlands are part of freshwater ecosystems. These ecosys- tems vary by temperature, pressure (in lakes), the amount of light that penetrates and the type of vegetation that lives there. "
__________________ is the study of bodies of freshwater and the organisms that live there.,(A) Lakeology (B) Oceanography (C) Limnology (D) Biology,C,"Organisms that live in lakes, ponds, streams, springs or wetlands are part of freshwater ecosystems. These ecosys- tems vary by temperature, pressure (in lakes), the amount of light that penetrates and the type of vegetation that lives there. "
which of these organisms would you not find in the deep-water zone of a lake?,(A) Fungi (B) Catfish (C) Bacteria (D) Photosynthesizers,D,"A lake is an example of a freshwater biome. Water in a lake generally forms three different zones based on water depth and distance from shore. The shallow water near the shore is called the littoral zone. It has diverse community of organisms. There is adequate light for photosynthesis and plenty of dissolved oxygen and nutrients. Producers include algae and aquatic plants (see Figure 23.20). Animals in this zone may include insects, crustaceans, fish, and turtles. The top layer of water farther from shore is called the limnetic zone. There is enough light for photosynthesis and plenty of dissolved oxygen. However, dissolved nutrients tend not to be as plentiful as they are in the littoral zone. Producers here are mainly phytoplankton. A variety of zooplankton and fish also occupy this zone. The deeper water of a lake makes up the profundal zone. There isnt enough light for photosynthesis in this zone, so most organisms here eat dead organisms that drift down from the water above. Organisms in the profundal zone may include clams, snails, and some species of fish. "
the sloped side of a lake where sunlight penetrates is the,(A) Aphotic zone (B) Photic zone (C) Littoral Zone (D) Limnetic Zone,C,Almost all surfaces reflect some of the light that strikes them. The still water of the lake in Figure 22.9 reflects almost all of the light that strikes it. The reflected light forms an image of nearby objects. An image is a copy of an object that is formed by reflected or refracted light. 
wetlands are,(A) Worthless swamps (B) The only home for some specialized species (C) Lands that are at the edges of the ocean (D) All of the above,B,Wetlands are lands that are wet for significant periods of time. They are common where water and land meet. Wetlands can be large flat areas or relatively small and steep areas. Wetlands are rich and unique ecosystems with many species that rely on both the land and the water for survival. Only specialized plants are able to grow in these conditions. Wetlands tend have a great deal of biological diversity. Wetland ecosystems can also be fragile systems that are sensitive to the amount and quality of water present within them. Click image to the left or use the URL below. URL: 
marshes are distinctive because,(A) They have lots of trees (B) Grasses and reeds are common (C) Reptiles have high biodiversity (D) All of the above,B,"Marshes are shallow wetlands around lakes, streams, or the ocean where grasses and reeds are common, but trees are not (Figure 1.2). Frogs, turtles, muskrats, and many varieties of birds are at home in marshes. A salt marsh on Cape Cod in Mas- sachusetts. "
swamps are distinctive because,(A) They can have freshwater (B) salt water or a mixture of both (C) b They are only infrequently inundated with water (D) c They have grasses and reeds (E) but few trees (F) d All of these,A,"A swamp is a wetland with lush trees and vines found in low-lying areas beside slow-moving rivers (Figure 1.3). Like marshes, they are frequently or always inundated with water. Since the water in a swamp moves slowly, oxygen in the water is often scarce. Swamp plants and animals must be adapted for these low-oxygen conditions. Like marshes, swamps can be fresh water, salt water, or a mixture of both. "
wetlands make up more than 30% of the land in the u.s. but have only 5% of the plant types.,(A) True (B) False,B,"As mentioned above, wetlands are home to many different species of organisms. Although they make up only 5% of the area of the United States, wetlands contain more than 30% of the plant types. Many endangered species live in wetlands, so wetlands are protected from human use. Wetlands also play a key biological role by removing pollutants from water. For example, they can trap and use fertilizer that has washed off a farmers field, and therefore they prevent that fertilizer from contaminating another body of water. Since wetlands naturally purify water, preserving wetlands also helps to maintain clean supplies of water. "
wetlands never contain more than a few trees.,(A) True (B) False,B,"Heavily vegetated lands are less likely to experience flooding. Plants slow down water as it runs over the land, giving it time to enter the ground. Even if the ground is too wet to absorb more water, plants still slow the waters passage and increase the time between rainfall and the waters arrival in a stream; this could keep all the water falling over a region from hitting the stream at once. Wetlands act as a buffer between land and high water levels and play a key role in minimizing the impacts of floods. Flooding is often more severe in areas that have been recently logged. "
"wetlands have important roles in the ecology of an area. for example, they",(A) Trap and use fertilizer so that it doesn’t contaminate another water body (B) Naturally purify water (C) Are home to many endangered species (D) All of the above,D,"As mentioned above, wetlands are home to many different species of organisms. Although they make up only 5% of the area of the United States, wetlands contain more than 30% of the plant types. Many endangered species live in wetlands, so wetlands are protected from human use. Wetlands also play a key biological role by removing pollutants from water. For example, they can trap and use fertilizer that has washed off a farmers field, and therefore they prevent that fertilizer from contaminating another body of water. Since wetlands naturally purify water, preserving wetlands also helps to maintain clean supplies of water. "
galaxies can contain billions or trillions of stars.,(A) True (B) False,A,"Galaxies are the biggest groups of stars and can contain anywhere from a few million stars to many billions of stars. Every star that is visible in the night sky is part of the Milky Way Galaxy. To the naked eye, the closest major galaxy the Andromeda Galaxy, shown in Figure 1.1  looks like only a dim, fuzzy spot. But that fuzzy spot contains one trillion  1,000,000,000,000  stars! Galaxies are divided into three types according to shape: spiral galaxies, elliptical galaxies, and irregular galaxies. "
earth is a part of the _____________.,(A) Sombrero Galaxy (B) Milky Way Galaxy (C) Andromeda Galaxy (D) Pinwheel Galaxy,B,Earth formed at the same time as the other planets. The history of Earth is part of the history of the Solar System. 
the closest galaxy to us is the ____________.,(A) Sombrero Galaxy (B) Milky Way Galaxy (C) Andromeda Galaxy (D) Pinwheel Galaxy,C,"The biggest groups of stars are called galaxies. A few million to many billions of stars may make up a galaxy. With the unaided eye, every star you can see is part of the Milky Way Galaxy. All the other galaxies are extremely far away. The closest spiral galaxy, the Andromeda Galaxy, shown in Figure 26.8, is 2,500,000 light years away and contains one trillion stars! "
which of these is not a type of galaxy?,(A) Spiral (B) Elliptical (C) Irregular (D) Circular,D,"Look at the galaxy in Figure 26.11. Do you think this is a spiral galaxy or an elliptical galaxy? It doesnt look like either! If a galaxy is not spiral or elliptical, it is an irregular galaxy. Most irregular galaxies have been deformed. This can occur either by the pull of a larger galaxy or by a collision with another galaxy. "
what is true about spiral galaxies?,(A) They appear as a rotating disk of stars (B) They appear to have a bulge in the middle (C) They have spiral arms (D) All of the above,D,"Spiral galaxies spin, so they appear as a rotating disk of stars and dust, with a bulge in the middle, like the Sombrero Galaxy shown in Figure 1.2. Several arms spiral outward in the Pinwheel Galaxy (seen in Figure 1.2) and are appropriately called spiral arms. Spiral galaxies have lots of gas and dust and lots of young stars. The Andromeda Galaxy is a large spiral galaxy similar to the Milky Way. (a) The Sombrero Galaxy is a spiral galaxy that we see from the side so the disk and central bulge are visible. (b) The Pinwheel Galaxy is a spiral galaxy that we see face-on so we can see the spiral arms. Because they contain lots of young stars, spiral arms tend to be blue. "
the arms in a spiral galaxy tend to be __________ because they contain __________.,(A) Red; old stars (B) Yellow; middle-aged stars (C) Blue; young stars (D) All colors; all age stars,C,"Spiral galaxies spin, so they appear as a rotating disk of stars and dust, with a bulge in the middle, like the Sombrero Galaxy shown in Figure 1.2. Several arms spiral outward in the Pinwheel Galaxy (seen in Figure 1.2) and are appropriately called spiral arms. Spiral galaxies have lots of gas and dust and lots of young stars. The Andromeda Galaxy is a large spiral galaxy similar to the Milky Way. (a) The Sombrero Galaxy is a spiral galaxy that we see from the side so the disk and central bulge are visible. (b) The Pinwheel Galaxy is a spiral galaxy that we see face-on so we can see the spiral arms. Because they contain lots of young stars, spiral arms tend to be blue. "
irregular galaxies may be deformed by gravitational attraction to another galaxy.,(A) True (B) False,A,"Look at the galaxy in Figure 26.11. Do you think this is a spiral galaxy or an elliptical galaxy? It doesnt look like either! If a galaxy is not spiral or elliptical, it is an irregular galaxy. Most irregular galaxies have been deformed. This can occur either by the pull of a larger galaxy or by a collision with another galaxy. "
an elliptical galaxy,(A) Does not contain dust because the dust has come together to form stars (B) May contain dust if it has collided with another galaxy of similar size (C) Is likely to be reddish to yellowish because it contains mostly old stars (D) All of the above,D,Figure 26.10 shows a typical elliptical galaxy. Elliptical galaxies are oval in shape. The smallest are called dwarf elliptical galaxies. Look back at the image of the Andromeda Galaxy. It has two dwarf elliptical galaxies as its companions. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Giant elliptical galaxies contain over a trillion stars. Elliptical galaxies are red to yellow in color because they contain mostly old stars. Most contain very little gas and dust because the material has already formed into stars. 
what is true about dwarf galaxies?,(A) They are relatively small and dim (B) They are all irregular in shape (C) They may merge with other galaxies (D) All of the above,A,"Dwarf galaxies are small galaxies containing only a few million to a few billion stars. Dwarf galaxies are the most common type in the universe. However, because they are relatively small and dim, we dont see as many dwarf galaxies from Earth. Most dwarf galaxies are irregular in shape. However, there are also dwarf elliptical galaxies and dwarf spiral galaxies. Look back at the picture of the elliptical galaxy. In the figure, you can see two dwarf elliptical galaxies that are companions to the Andromeda Galaxy. One is a bright sphere to the left of center, and the other is a long ellipse below and to the right of center. Dwarf galaxies are often found near larger galaxies. They sometimes collide with and merge into their larger neighbors. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
the geologic time scale was originally based,(A) Entirely on absolute ages (B) On a mix of relative and absolute ages (C) Entirely on relative ages (D) On random events,C,"To create the geologic time scale, geologists correlated rock layers. Stenos laws were used to determine the relative ages of rocks. Older rocks are at the bottom and younger rocks are at the top. The early geologic time scale could only show the order of events. The discovery of radioactivity in the late 1800s changed that. Scientists could determine the exact age of some rocks in years. They assigned dates to the time scale divisions. For example, the Jurassic began about 200 million years ago. It lasted for about 55 million years. "
time units on the geologic time scale are,(A) Divided into 10 million year blocks (B) Separated by important events in geological or biological history (C) Divided using absolute age dates (D) Separated by distinctive rock units,B,"The largest blocks of time on the geologic time scale are called eons. Eons are split into eras. Each era is divided into periods. Periods may be further divided into epochs. Geologists may just use early or late. An example is late Jurassic, or early Cretaceous. Figure 11.13 shows you what the geologic time scale looks like. "
"we live in the holocene epoch, as well as the",(A) Quaternary period (B) Cenozoic Era (C) Phanerozoic Eon (D) All of the above,D,"We now live in the Phanerozoic Eon, the Cenozoic Era, the Quaternary Period, and the Holocene Epoch. Phanero- zoic means visible life. During this eon, rocks contain visible fossils. Before the Phanerozoic, life was microscopic. The Cenozoic Era means new life. It encompasses the most recent forms of life on Earth. The Cenozoic is sometimes called the Age of Mammals. Before the Cenozoic came the Mesozoic and Paleozoic. The Mesozoic means middle life. This is the age of reptiles, when dinosaurs ruled the planet. The Paleozoic is old life. Organisms like invertebrates and fish were the most common lifeforms. "
"if earth history is condensed into one calendar year, dinosaurs appear",(A) In late February (B) In mid-September (C) In mid-December (D) On the night of December 31st,C,"Its always fun to think about geologic time in a framework that we can more readily understand. Here are when some major events in Earth history would have occurred if all of earth history was condensed down to one calendar year. January 1 12 am: Earth forms from the planetary nebula - 4600 million years ago February 25, 12:30 pm: The origin of life; the first cells - 3900 million years ago March 4, 3:39 pm: Oldest dated rocks - 3800 million years ago March 20, 1:33 pm: First stromatolite fossils - 3600 million years ago July 17, 9:54 pm: first fossil evidence of cells with nuclei - 2100 million years ago November 18, 5:11 pm: Cambrian Explosion - 544 million years ago December 1, 8:49 am: first insects - 385 million years ago December 2, 3:54 am: first land animals, amphibians - 375 million years ago December 5, 5:50 pm: first reptiles - 330 million years ago December 12, 12:09 pm: Permo-Triassic Extinction - 245 million years ago December 13, 8:37 pm: first dinosaurs - 228 million years ago December 14, 9:59 am: first mammals  220 million years ago December 22, 8:24 pm: first flowering plants - 115 million years ago December 26, 7:52 pm: Cretaceous-Tertiary Extinction - 66 million years ago December 26, 9:47 pm: first ancestors of dogs - 64 million years ago December 27, 5:25 am: widespread grasses - 60 million years ago December 27, 11:09 am: first ancestors of pigs and deer - 57 million years ago December 28, 9:31 pm: first monkeys - 39 million years ago December 31, 5:18 pm: oldest hominid - 4 million years ago December 31, 11:02 pm: oldest direct human ancestor - 1 million years ago December 31, 11:48 pm: first modern human - 200,000 years ago December 31, 11:59 pm: Revolutionary War - 235 years ago "
"if earth history is condensed into one calendar year, the first modern humans appear",(A) In late September (B) In mid-November (C) In mid-December (D) On the night of December 31st,D,"Its always fun to think about geologic time in a framework that we can more readily understand. Here are when some major events in Earth history would have occurred if all of earth history was condensed down to one calendar year. January 1 12 am: Earth forms from the planetary nebula - 4600 million years ago February 25, 12:30 pm: The origin of life; the first cells - 3900 million years ago March 4, 3:39 pm: Oldest dated rocks - 3800 million years ago March 20, 1:33 pm: First stromatolite fossils - 3600 million years ago July 17, 9:54 pm: first fossil evidence of cells with nuclei - 2100 million years ago November 18, 5:11 pm: Cambrian Explosion - 544 million years ago December 1, 8:49 am: first insects - 385 million years ago December 2, 3:54 am: first land animals, amphibians - 375 million years ago December 5, 5:50 pm: first reptiles - 330 million years ago December 12, 12:09 pm: Permo-Triassic Extinction - 245 million years ago December 13, 8:37 pm: first dinosaurs - 228 million years ago December 14, 9:59 am: first mammals  220 million years ago December 22, 8:24 pm: first flowering plants - 115 million years ago December 26, 7:52 pm: Cretaceous-Tertiary Extinction - 66 million years ago December 26, 9:47 pm: first ancestors of dogs - 64 million years ago December 27, 5:25 am: widespread grasses - 60 million years ago December 27, 11:09 am: first ancestors of pigs and deer - 57 million years ago December 28, 9:31 pm: first monkeys - 39 million years ago December 31, 5:18 pm: oldest hominid - 4 million years ago December 31, 11:02 pm: oldest direct human ancestor - 1 million years ago December 31, 11:48 pm: first modern human - 200,000 years ago December 31, 11:59 pm: Revolutionary War - 235 years ago "
naming time periods makes it easier to talk about them.,(A) True (B) False,A,"To be able to discuss Earth history, scientists needed some way to refer to the time periods in which events happened and organisms lived. With the information they collected from fossil evidence and using Stenos principles, they created a listing of rock layers from oldest to youngest. Then they divided Earths history into blocks of time with each block separated by important events, such as the disappearance of a species of fossil from the rock record. Since many of the scientists who first assigned names to times in Earths history were from Europe, they named the blocks of time from towns or other local places where the rock layers that represented that time were found. From these blocks of time the scientists created the geologic time scale (Figure 1.1). In the geologic time scale the youngest ages are on the top and the oldest on the bottom. Why do you think that the more recent time periods are divided more finely? Do you think the divisions in the scale below are proportional to the amount of time each time period represented in Earth history? In what eon, era, period and epoch do we now live? We live in the Holocene (sometimes called Recent) epoch, Quaternary period, Cenozoic era, and Phanerozoic eon. "
about 1/8 of earth history passed before the explosion of life forms in the cambrian.,(A) True (B) False,B,"The Cambrian began with the most rapid and far-reaching evolution of life forms ever in Earths history. Evolving to inhabit so many different habitats resulted in a tremendous diversification of life forms. Shallow seas covered the lands, so every major marine organism group, including nearly all invertebrate animal phyla, evolved during this time. With the evolution of hard body parts, fossils are much more abundant and better preserved from this period than from the Precambrian. The Burgess shale formation in the Rocky Mountains of British Columbia, Canada, contains an amazing diversity of middle Cambrian life forms, from about 505 million years ago. Paleontologists do not agree on whether the Burgess shale fossils can all be classified into modern groups of organisms or whether many represent lines that have gone completely extinct. "
many of the blocks of time on the geologic time scale were named for,(A) Nearby towns where the rock layer from that time were found (B) Locations in North America (C) The geologists who worked in those rock sections (D) All of these,A,"To be able to discuss Earth history, scientists needed some way to refer to the time periods in which events happened and organisms lived. With the information they collected from fossil evidence and using Stenos principles, they created a listing of rock layers from oldest to youngest. Then they divided Earths history into blocks of time with each block separated by important events, such as the disappearance of a species of fossil from the rock record. Since many of the scientists who first assigned names to times in Earths history were from Europe, they named the blocks of time from towns or other local places where the rock layers that represented that time were found. From these blocks of time the scientists created the geologic time scale (Figure 1.1). In the geologic time scale the youngest ages are on the top and the oldest on the bottom. Why do you think that the more recent time periods are divided more finely? Do you think the divisions in the scale below are proportional to the amount of time each time period represented in Earth history? In what eon, era, period and epoch do we now live? We live in the Holocene (sometimes called Recent) epoch, Quaternary period, Cenozoic era, and Phanerozoic eon. "
"eon, era, period, epoch is the order from the largest amount of time to the smallest amount of time.",(A) True (B) False,A,"The largest blocks of time on the geologic time scale are called eons. Eons are split into eras. Each era is divided into periods. Periods may be further divided into epochs. Geologists may just use early or late. An example is late Jurassic, or early Cretaceous. Figure 11.13 shows you what the geologic time scale looks like. "
"compared with older time periods, more recent time periods on the geologic time scale",(A) Are divided into more segments (B) Are about as well understood (C) Are more difficult to learn about (D) All of these,A,"Another tool for understanding the history of Earth and its life is the geologic time scale. You can see this time scale in Figure 7.18. It divides Earths history into eons, eras, and periods. These divisions are based on major changes in geology, climate, and the evolution of life. The geologic time scale organizes Earths history on the basis of important events instead of time alone. It also puts more focus on recent events, about which we know the most. "
force per unit area that is placed on an object.,(A) Strain (B) Pressure (C) Stress (D) Deformation,C,"Pressure is the result of force acting on a given area. It can be represented by the equation: Pressure = Force Area Pressure shows how concentrated the force is on a given area. The smaller the area to which force is applied, the greater the pressure is. Think about pressing a pushpin, like the one in Figure 15.2, into a bulletin board. You apply force with your thumb to the broad head of the pushpin. However, the force that the pushpin applies to the bulletin board acts only over the tiny point of the pin. This is a much smaller area, so the pressure the point applies to the bulletin board is much greater than the pressure you apply with you thumb. As a result, the pin penetrates the bulletin board with ease. "
a rocks response to stress depends on,(A) The type of rock and the type of stress (B) The surrounding temperature (C) The amount of time the rock is under stress (D) All of the above,D,"Rocks have three possible responses to increasing stress (illustrated in Figure 1.3): elastic deformation: the rock returns to its original shape when the stress is removed. plastic deformation: the rock does not return to its original shape when the stress is removed. fracture: the rock breaks. Under what conditions do you think a rock is more likely to fracture? Is it more likely to break deep within Earths crust or at the surface? What if the stress applied is sharp rather than gradual? At the Earths surface, rocks usually break quite quickly, but deeper in the crust, where temperatures and pressures are higher, rocks are more likely to deform plastically. Sudden stress, such as a hit with a hammer, is more likely to make a rock break. Stress applied over time often leads to plastic deformation. Click image to the left or use the URL below. URL: "
rocks that are pulled apart are under,(A) Tension (B) Shearing (C) Compression (D) Confining,A,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
parallel forces moving in opposite directions are,(A) Tension (B) Shear (C) Compression (D) Confining Stress,B,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
a sudden stress is more likely to make a rock fracture than a show increasing stress.,(A) True (B) False,A,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
stress that causes a material to change its shape is called,(A) Elasticity (B) Plasticity (C) Fracture (D) Deformation,D,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
rock that returns to its original shape when the stress is removed.,(A) Fracture (B) Plastic deformation (C) Elastic deformation (D) Shearing,C,"Rocks have three possible responses to increasing stress (illustrated in Figure 1.3): elastic deformation: the rock returns to its original shape when the stress is removed. plastic deformation: the rock does not return to its original shape when the stress is removed. fracture: the rock breaks. Under what conditions do you think a rock is more likely to fracture? Is it more likely to break deep within Earths crust or at the surface? What if the stress applied is sharp rather than gradual? At the Earths surface, rocks usually break quite quickly, but deeper in the crust, where temperatures and pressures are higher, rocks are more likely to deform plastically. Sudden stress, such as a hit with a hammer, is more likely to make a rock break. Stress applied over time often leads to plastic deformation. Click image to the left or use the URL below. URL: "
rocks that break under a lot of stress.,(A) Fracture (B) Plastic deformation (C) Elastic deformation (D) Shearing,A,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
tension occurs at divergent boundaries.,(A) True (B) False,A,Plates move apart at divergent plate boundaries. This can occur in the oceans or on land. 
this type of stress occurs at convergent boundaries.,(A) Shearing (B) Compression (C) Tension (D) No stress,B,"Stress is the force applied to a rock. There are four types of stresses: Confining stress happens as weight of all the overlying rock pushes down on a deeply buried rock. The rock is being pushed in from all sides, which compresses it. The rock will not deform because there is no place for it to move. Compression stress squeezes rocks together. Compression causes rocks to fold or fracture (Figure 7.1). When two cars collide, compression causes them to crumple. Compression is the most common stress at convergent plate boundaries. Tension stress pulls rocks apart. Tension causes rocks to lengthen or break apart. Tension is the major type of stress found at divergent plate boundaries. Shear stress happens when forces slide past each other in opposite directions (Figure 7.2). This is the most common stress found at transform plate boundaries. The amount of stress on a rock may be greater than the rocks strength. In that case, the rock will change and deform (Figure 7.3). Deep within the Earth, the pressure is very great. A rock behaves like a stretched rubber band. When the stress stops, the rock goes back to its original shape. If more stress is applied to the rock, it bends and flows. It does not return to its original shape. Near the surface, if the stress continues, the rock will fracture and break. "
california is the best developed location in the u.s. for geothermal energy because,(A) It is geologically active and heat sources are close to the surface (B) The state has the technology to drill deeply to get to the hot rock (C) It is the location of Yellowstone National Park (D) None of these,A,"Where Earths internal heat gets close to the surface, geothermal power is a clean source of energy. In California, The Geysers supplies energy for many nearby homes and businesses. Learn more at: http://science.kqed.org/ques MEDIA Click image to the left or use the URL below. URL: "
where does geothermal energy come from?,(A) Outer space (B) Earth’s internal heat (C) The water cycle (D) The sun,B,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
"to harness geothermal energy,",(A) Plants must be built where hot water rises to the surface (B) Cool water is pumped to depth and warm water is pumped back up (C) Steam rises to spin a turbine (D) All of these,D,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
electricity is generated at a hydrothermal plant when,(A) Hot water passes downstream through a turbine (B) Hot water travels through pipes and into homes for heat and electricity (C) Steam from a geothermal well spins a turbine (D) None of these,C,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
geothermal energy creates greenhouse gases and other pollutants.,(A) True (B) False,B,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
"at any geothermal plant, the energy will run out as cold water cools the hot rock.",(A) True (B) False,B,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
this country gets about one fourth of its electricity from geothermal sources.,(A) China (B) Turkey (C) Iceland (D) Nigeria,C,"Solar and wind power may get the headlines when it comes to renewable energy. But another type of clean power is heating up in the hills just north of Sonoma wine country. Geothermal power uses heat from deep inside the Earth to generate electricity. The Geysers, the worlds largest power-producing geothermal field, has been providing electricity for roughly 850,000 Northern California households, and is set to expand even further. For more information on geothermal energy, see http://science.kqed.org/quest/video/geothermal-heats-up/ . MEDIA Click image to the left or use the URL below. URL: "
geothermal energy,(A) Is useful as it is harnessed (B) Must be processed (C) Must be stored before use (D) All of the above,A,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
the likely source of heat for the largest geothermal plant in california is a large magma chamber.,(A) True (B) False,A,"The heat that is used for geothermal power may come to the surface naturally as hot springs or geysers, like The Geysers in northern California. Where water does not naturally come to the surface, engineers may pump cool water into the ground. The water is heated by the hot rock and then pumped back to the surface for use. The hot water or steam from a geothermal well spins a turbine to make electricity. Geothermal energy is clean and safe. The energy source is renewable since hot rock is found everywhere in the Earth, although in many parts of the world the hot rock is not close enough to the surface for building geothermal power plants. In some areas, geothermal power is common (Figure 1.1). In the United States, California is a leader in producing geothermal energy. The largest geothermal power plant in the state is in the Geysers Geothermal Resource Area in Napa and Sonoma Counties. The source of heat is thought to be a large magma chamber lying beneath the area. Where Earths internal heat gets close to the surface, geothermal power is a clean source of energy. In California, The Geysers supplies energy for many nearby homes and businesses. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
"in some locations, hot rocks are too deep to be used for geothermal energy.",(A) True (B) False,A,"Because the hot water or steam can be used directly to make a turbine spin, geothermal energy can be used without processing. Geothermal energy is clean and safe. It is renewable. There will always be hot rocks and water can be pumped down into a well. There, the water can be heated again to make more steam. Geothermal energy is an excellent resource in some parts of the world. Iceland is gets about one fourth of its electricity from geothermal sources. In the United States, California leads all states in producing geothermal energy. Geothermal energy in California is concentrated in the northern part of the state. The largest plant is in the Geysers Geothermal Resource Area. Geothermal energy is not economical everywhere. Many parts of the world do not have underground sources of heat that are close enough to the surface for building geothermal power plants. "
where are glaciers found?,(A) Antarctica and Greenland only (B) Every continent except Australia (C) Every continent except Antarctica and Greenland (D) Australia only,B,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
"large glaciers that cover a larger area than just a valley, possibly an entire mountain range or region.",(A) Continental glacier (B) Alpine glacier (C) Ice caps (D) Valley glacier,C,"The types of glaciers are: Continental glaciers are large ice sheets that cover relatively flat ground. These glaciers flow outward from where the greatest amounts of snow and ice accumulate. Alpine (valley) glaciers flow downhill from where the snow and ice accumulates through mountains along existing valleys. Ice caps are large glaciers that cover a larger area than just a valley, possibly an entire mountain range or region. Glaciers come off of ice caps into valleys. The Greenland ice cap covers the entire landmass. "
a deep crack in the glacier that forms as a result of ice movement.,(A) Glacial breakage (B) Crack (C) Bergshrund (D) Crevasse,D,"Whether an ice field moves or not depends on the amount of ice in the field, the steepness of the slope and the roughness of the ground surface. Ice moves where the pressure is so great that it undergoes plastic flow. Ice also slides at the bottom, often lubricated by water that has melted and travels between the ground and the ice. The speed of a glacier ranges from extremely fast, where conditions are favorable, to nearly zero. Because the ice is moving, glaciers have crevasses, where cracks form in the ice as a result of movement. The large crevasse at the top of an alpine glacier where ice that is moving is separated from ice that is stuck to the mountain above is called a bergshrund. Crevasses in a glacier are the result of movement. "
the lower part of the glacier where the amount of snow and ice that melts off is the,(A) Zone of accumulation (B) Zone of ablation (C) Equilibrium line (D) None of these,B,"Glaciers are melting back in many locations around the world. When a glacier no longer moves, it is called an ice sheet. This usually happens when it is less than 0.1 km2 in area and 50 m thick. "
"when a glacier no longer moves, it is called an ice sheet.",(A) True (B) False,A,"Glaciers are melting back in many locations around the world. When a glacier no longer moves, it is called an ice sheet. This usually happens when it is less than 0.1 km2 in area and 50 m thick. "
whether an ice sheet is a glacier depends on,(A) The amount in the field (B) How steep the slope is (C) The roughness of the ground surface (D) All of the above,D,"Glaciers are melting back in many locations around the world. When a glacier no longer moves, it is called an ice sheet. This usually happens when it is less than 0.1 km2 in area and 50 m thick. "
how do glaciers move?,(A) By plastic flow at the bottom where the pressure is high (B) At the bottom where meltwater lubricates it (C) From extremely fast to nearly no movement (D) All of the above,D,"Whether an ice field moves or not depends on the amount of ice in the field, the steepness of the slope and the roughness of the ground surface. Ice moves where the pressure is so great that it undergoes plastic flow. Ice also slides at the bottom, often lubricated by water that has melted and travels between the ground and the ice. The speed of a glacier ranges from extremely fast, where conditions are favorable, to nearly zero. Because the ice is moving, glaciers have crevasses, where cracks form in the ice as a result of movement. The large crevasse at the top of an alpine glacier where ice that is moving is separated from ice that is stuck to the mountain above is called a bergshrund. Crevasses in a glacier are the result of movement. "
glacier national park has lost many of its active glaciers because,(A) Temperatures in that region have been rising (B) Plate tectonics is moving the region into a warmer location (C) People are ruining them with their hiking and ATV riding (D) None of the above,A,"Many of the glaciers in Glacier National Park have shrunk and are no longer active. Summer temperatures have risen rapidly in this part of the country and so the rate of melting has picked up. Whereas Glacier National Park had 150 glaciers in 1850, there are only about 25 today. Recent estimates are that the park will have no active glaciers as early as 2020. This satellite image shows Grinnell Glacier, Swiftcurrent Glacier, and Gem Glacier in 2003 with an outline of the extent of the glaciers as they were in 1950. Although it continues to be classified as a glacier, Gem Glacier is only 0.020 km2 (5 acres) in area, only one-fifth the size of the smallest active glaciers. "
glaciers are a resource because,(A) They are a source of water in the summer (B) They provide energy as the water turns from snow to glacial ice (C) They cover up vast mineral resources that are exposed when they melt (D) Gold dust and other valuable minerals land on glaciers and can be mined,A,"In regions where summers are long and dry, melting glaciers in mountain regions provide an important source of water for organisms and often for nearby human populations. Click image to the left or use the URL below. URL: "
"gem glacier in glacier national park is no longer moving, but it is still a glacier.",(A) True (B) False,B,"Many of the glaciers in Glacier National Park have shrunk and are no longer active. Summer temperatures have risen rapidly in this part of the country and so the rate of melting has picked up. Whereas Glacier National Park had 150 glaciers in 1850, there are only about 25 today. Recent estimates are that the park will have no active glaciers as early as 2020. This satellite image shows Grinnell Glacier, Swiftcurrent Glacier, and Gem Glacier in 2003 with an outline of the extent of the glaciers as they were in 1950. Although it continues to be classified as a glacier, Gem Glacier is only 0.020 km2 (5 acres) in area, only one-fifth the size of the smallest active glaciers. "
global average temperatures are increasing and we are already seeing the effects of this.,(A) True (B) False,A,"With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. "
"temperatures have been rising since __________, but the __________ is increasing.",(A) The beginning of the Pleistocene; rate of increase (B) Earth began; rate of decrease (C) Plants evolved; rate of decrease (D) The end of the Pleistocene; rate of increase,D,"Since the Pleistocene, Earths temperature has risen. Figure 17.18 shows how it changed over just the last 1500 years. There were minor ups and downs. But each time, the anomaly (the difference from average temperature) was less than 1 C (1.8 F). Since the mid 1800s, Earth has warmed up quickly. Look at Figure 17.19. The 14 hottest years on record have all occurred since 1900. Eight of them have occurred since 1998! This is what is usually meant by global warming. "
"_________ is the largest emitter of greenhouse gases, but ________ is the largest per capita emitter.",(A) Japan (B) the European Union (C) b China; The United States (D) c The United States; China (E) d The European Union; Japan,B,"The United States has long been the largest emitter of greenhouse gases, with about 20% of total emissions in 2004. As a result of Chinas rapid economic growth, its emissions surpassed those of the United States in 2008. However, its also important to keep in mind that the United States has only about one-fifth the population of China. Whats the significance of this? The average United States citizen produces far more greenhouse gas emissions than the average Chinese person. "
"when ice caps melt, the sea level decreases.",(A) True (B) False,B,"As Earth has gotten warmer, sea ice has melted. This has raised the level of water in the oceans. Figure 17.21 shows how much sea level has risen since 1880. "
warmer temperatures are causing coral reefs to,(A) Turn white (B) Turn red (C) Grow more rapidly (D) Grow higher in the water,A,"Corals and other animals deposit calcium carbonate to create rock reefs near the shore. Coral reefs are the rain- forests of the oceans, with a tremendous amount of species diversity (Figure 1.2). Reefs can form interesting shapes in the oceans. Remember that hot spots create volcanoes on the seafloor. If these volcanoes rise above sea level to become islands, and if they occur in tropical waters, coral reefs will form on them. Since the volcanoes are cones, the reef forms in a circle around the volcano. As the volcano comes off the hot spot, the crust cools. The volcano subsides and then begins to erode away (Figure 1.3). Eventually, all that is left is a reef island called an atoll. A lagoon is found inside the reef. "
burning fossil fuels adds greenhouse gases to the air.,(A) True (B) False,A,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
which of these is affected by global warming?,(A) Mating and migration of birds (B) Glaciers (C) Plant life (D) All of the above,D,"The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: "
"permafrost is melting, but its extent is increasing.",(A) True (B) False,B,"The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: "
"to find a location that it is more suited to in temperature, a species will",(A) Move uphill (B) Move downhill (C) Move to a different ecosystem (D) Move to a different continent,A,"Birds are endothermic. They can maintain a warm body temperature even in a cold climate. Therefore, they can live in a wider range of habitats than ectothermic vertebrates such as amphibians and reptiles. "
"in california and elsewhere, warmer temperatures are causing",(A) More snow in the winter (B) More rain year-round (C) Changes in the ecology of the state (D) All of these,C,"The temperature of the water offshore influences the temperature of a coastal location, particularly if the winds come off the sea. The cool waters of the California Current bring cooler temperatures to the California coastal region. Coastal upwelling also brings cold, deep water up to the ocean surface off of California, which contributes to the cool coastal temperatures. Further north, in southern Alaska, the upwelling actually raises the temperature of the surrounding land because the ocean water is much warmer than the land. The important effect of the Gulf Stream on the climate of northern Europe is described in the chapter Water on Earth. "
gravitational force depends on _____________.,(A) The mass of the objects (B) The distance of the objects (C) The volume of the objects (D) Both a and b,D,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity. For example, because Earth is so massive, it attracts you and your desk more strongly than you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. This is illustrated in Figure You can apply these relationships among mass, distance, and gravity by designing your own roller coaster at this URL:  . "
"the greater an objects mass, the greater the force of attraction.",(A) True (B) False,A,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity. For example, because Earth is so massive, it attracts you and your desk more strongly than you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. This is illustrated in Figure You can apply these relationships among mass, distance, and gravity by designing your own roller coaster at this URL:  . "
"the farther the distance between two objects, the greater the attraction.",(A) True (B) False,B,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity. For example, because Earth is so massive, it attracts you and your desk more strongly than you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. This is illustrated in Figure You can apply these relationships among mass, distance, and gravity by designing your own roller coaster at this URL:  . "
this famous scientist was first to discover the principal of gravity.,(A) Galileo Galilei (B) Sir Isaac Newton (C) Albert Einstein (D) Erwin Schrodinger,B,"People have known about gravity for thousands of years. After all, they constantly experienced gravity in their daily lives. They knew that things always fall toward the ground. However, it wasnt until Sir Isaac Newton developed his law of gravity in the late 1600s that people really began to understand gravity. Newton is pictured in Figure 13.17. "
which of these planets experiences the weakest gravitational pull to the sun?,(A) Venus (B) Mercury (C) Jupiter (D) Neptune,D,"The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. "
which of these planets experiences the strongest gravitational pull from the sun?,(A) Earth (B) Mercury (C) Mars (D) Venus,B,"Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a string. The force pulling the planet is the pull of gravity between the planet and the Sun. Every object is attracted to every other object by gravity. The force of gravity between two objects depends on the mass of the objects. It also depends on how far apart the objects are. When you are sitting next to your dog, there is a gravitational force between the two of you. That force is far too weak for you to notice. You can feel the force of gravity between you and Earth because Earth has a lot of mass. The force of gravity between the Sun and planets is also very large. This is because the Sun and the planets are very large objects. Gravity is great enough to hold the planets to the Sun even though the distances between them are enormous. Gravity also holds moons in orbit around planets. "
which of the planets in our solar system has the greatest gravitational pull?,(A) Neptune (B) Uranus (C) Saturn (D) Jupiter,D,"Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a string. The force pulling the planet is the pull of gravity between the planet and the Sun. Every object is attracted to every other object by gravity. The force of gravity between two objects depends on the mass of the objects. It also depends on how far apart the objects are. When you are sitting next to your dog, there is a gravitational force between the two of you. That force is far too weak for you to notice. You can feel the force of gravity between you and Earth because Earth has a lot of mass. The force of gravity between the Sun and planets is also very large. This is because the Sun and the planets are very large objects. Gravity is great enough to hold the planets to the Sun even though the distances between them are enormous. Gravity also holds moons in orbit around planets. "
"if you are on the top of a mountain and drop an apple, it will fall to the ground, even though the apple is gravitationally attracted to you. why?",(A) Earth is larger and has a much stronger gravitational pull (B) Apples always fall down (C) Centrifugal forces pull the apple to the Earth and that is stronger than your gravitational pull (D) None of these,A,"You are already very familiar with Earths gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects that are above the surfacefrom meteors to skydiversdown to the ground. Gravity between Earth and the moon and between Earth and artificial satellites keeps all these objects circling around Earth. Gravity also keeps Earth and the other planets moving around the much more massive sun. Q: There is a force of gravity between Earth and you and also between you and all the objects around you. When you drop a paper clip, why doesnt it fall toward you instead of toward Earth? A: Earth is so much more massive than you that its gravitational pull on the paper clip is immensely greater. "
"the planets are all really far from the sun, but they continue to orbit the star because",(A) The Sun and the planets are all really large (B) The Sun’s gravity increases with distance from it (C) Centrifugal forces continue to operate even when two objects are too far for gravity (D) Space has fibers that keep the planets orbiting the Sun,A,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
which is a greenhouse gas?,(A) Carbon dioxide (B) Water vapor (C) Ozone (D) All of the above,D,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
"volcanic eruptions, decomposition of plant material, respiration, and fossil fuel burning all release this greenhouse gas.",(A) Carbon dioxide (B) Methane (C) Nitrous oxide (D) Ozone,A,"Atmospheric CO2 has increased over the past five decades, because the amount of CO2 gas released by volcanoes has increased. "
how is the atmosphere like a greenhouse?,(A) Greenhouse gases reflect sunlight like the walls of a greenhouse (B) Water vapor condenses into clouds like droplets condense on greenhouse walls (C) Greenhouse gases trap heat like the walls of a greenhouse (D) None of the above,C,"Along with the oceans, the atmosphere keeps Earths temperatures within an acceptable range. Without an atmo- sphere, Earths temperatures would be frigid at night and scorching during the day. If the 12-year-old in the scenario above asked why, she would find out. Greenhouse gases trap heat in the atmosphere. Important greenhouse gases include carbon dioxide, methane, water vapor, and ozone. "
"energy that comes off of earths surface,",(A) Is directly radiated into space (B) Is absorbed by greenhouse gases in the atmosphere (C) Is altered so that it becomes cooler in the atmosphere (D) A & B,D,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
all greenhouse gases are emitted by natural processes.,(A) True (B) False,B,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
which of these is the most abundant greenhouse gas?,(A) Carbon dioxide (B) Methane (C) Nitrous oxide (D) Ozone,A,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
"one cfc-12 molecule traps 10,600 times as much heat as one co2 molecule.",(A) True (B) False,A,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
atmospheric greenhouse gas levels are increasing due to human activities.,(A) True (B) False,A,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
greenhouse effect is,(A) Bad for Earth because it is warming us up too much (B) Bad for Earth because it moderates our temperature (C) A natural phenomenon that is important for making Earth habitable (D) None of these,C,"When sunlight heats Earths surface, some of the heat radiates back into the atmosphere. Some of this heat is absorbed by gases in the atmosphere. This is the greenhouse effect, and it helps to keep Earth warm. The greenhouse effect allows Earth to have temperatures that can support life. Gases that absorb heat in the atmosphere are called greenhouse gases. They include carbon dioxide and water vapor. Human actions have increased the levels of greenhouse gases in the atmosphere. This is shown in Figure 15.11. The added gases have caused a greater greenhouse effect. How do you think this affects Earths temperature? "
what happens when greenhouse gas levels in the atmosphere increase?,(A) Nothing (B) The atmosphere traps more heat (C) The atmosphere traps less heat (D) None of the above,B,Human activity has significantly raised the levels of many of greenhouse gases in the atmosphere. Methane levels are about 2 1/2 times higher as a result of human activity. Carbon dioxide has increased more than 35%. CFCs have only recently existed. What do you think happens as atmospheric greenhouse gas levels increase? More greenhouse gases trap more heat and warm the atmosphere. The increase or decrease of greenhouse gases in the atmosphere affect climate and weather the world over. Click image to the left or use the URL below. URL: 
"in an aquifer, pore spaces above this line do not contain water and below this line do contain water.",(A) Impermeable layer (B) Bedrock (C) Water table (D) Spring,C,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
"in a drought, the water table",(A) Will not change (B) It’s not possible to know what it will do (C) Will go up (D) Will go down,D,"The top of the saturated rock layer in Figure 13.11 is called the water table. The water table isnt like a real table. It doesnt remain firmly in one place. Instead, it rises or falls, depending on how much water seeps down from the surface. The water table is higher when there is a lot of rain and lower when the weather is dry. "
people have learned to tap groundwater sources that were previously out of reach by,(A) Finding springs (B) Drilling wells (C) Using streams (D) None of these,B,"Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water thats stored in an aquifer people must go after it. How? They dig a well. A well is a hole that is dug or drilled through the ground down to an aquifer. This is illustrated in Figure 13.18. People have depended on water from wells for thousands of years. To bring water to the surface takes energy because the force of gravity must be overcome. Today, many wells use electricity to pump water to the surface. However, in some places, water is still brought to the surface the old-fashioned way  with human labor. The well pictured in Figure 13.19 is an example of this type of well. A hand-cranked pulley is used to lift the bucket of water to the surface. "
if you were going to drill a well into an aquifer it would be a shorter distance to drill down into a valley than down into a hill.,(A) True (B) False,A,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
the surface of a stream is,(A) The top of the water table (B) The bottom of the water table (C) Where a spring runs in (D) None of these,A,"A stream is a body of freshwater that flows downhill in a channel. The channel of a stream has a bottom, or bed, and sides called banks. Any size body of flowing water can be called a stream. Usually, though, a large stream is called a river. "
"in a desert, water only runs in streambeds (called washes) during a large rainstorm. why do streams not run in washes all the time?",(A) There is never an aquifer below a desert (B) A desert stream is like other streams; there is water when there is rain or snowmelt (C) The water table is too deep and does not intercept the streambed (D) None of these,C,"Most precipitation that occurs over land, however, is not absorbed by the soil and is called runoff. This runoff collects in streams and rivers and eventually flows back into the ocean. "
all springs flow all year round.,(A) True (B) False,B,"Groundwater meets the surface in a stream (Figure 1.2) or a spring (Figure 1.3). A spring may be constant, or may only flow at certain times of year. Towns in many locations depend on water from springs. Springs can be an extremely important source of water in locations where surface water is scarce. "
"to be a good aquifer, the only important quality for a rock to have is high porosity.",(A) True (B) False,B,"To be a good aquifer, the rock in the aquifer must have good: porosity: small spaces between grains permeability: connections between pores To reach an aquifer, surface water infiltrates downward into the ground through tiny spaces or pores in the rock. The water travels down through the permeable rock until it reaches a layer that does not have pores; this rock is impermeable (Figure 1.1). This impermeable rock layer forms the base of the aquifer. The upper surface where the groundwater reaches is the water table. Groundwater is found beneath the solid surface. Notice that the water table roughly mirrors the slope of the lands surface. A well penetrates the water table. "
wells may go completely dry if they are not deep enough to reach in a lowered water table.,(A) True (B) False,A,"Some aquifers are overused; people pump out more water than is replaced. As the water is pumped out, the water table slowly falls, requiring wells to be dug deeper, which takes more money and energy. Wells may go completely dry if they are not deep enough to reach into the lowered water table. Other problems may stem from groundwater overuse. Subsidence and saltwater intrusion are two of them. "
which of these regions has intense droughts and reduced groundwater levels?,(A) Northeast (B) Pacific Northwest (C) Midwest (D) South,D,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
this aquifer supplies one-third of the irrigation water in the united states.,(A) Hetch-Hetchy (B) Ogallala (C) Quabbin (D) None of the above,B,"The Ogallala Aquifer supplies about one-third of the irrigation water in the United States. The Ogallala Aquifer is widely used by people for municipal and agricultural needs. (Figure 1.2). The aquifer is found from 30 to 100 meters deep over an area of about 440,000 square kilometers! The water in the aquifer is mostly from the last ice age. About eight times more water is taken from the Ogallala Aquifer each year than is replenished. Much of the water is used for irrigation (Figure 1.3). Click image to the left or use the URL below. URL:  Intense drought has reduced groundwater levels in the southern U.S., particularly in Texas and New Mexico. "
"land in some places, like the san joaquin valley of california, has undergone subsidence, which is due to",(A) Too much farming (B) The aging of the groundwater aquifer (C) A change from drip irrigation to overhead sprinklers for irrigation (D) Overpumping groundwater,D,"The San Andreas Fault in California is a right-lateral strike-slip fault (Figure 7.15). It is also a transform fault because the San Andreas is a plate boundary. As you can see, California will not fall into the ocean someday. The land west of the San Andreas Fault is moving northeastward, while the North American plate moves southwest. Someday, millions of years from now, Los Angeles will be a suburb of San Francisco! "
"in coastal regions, when an aquifer gets low, this might happen.",(A) A reduction in farming (B) Drought (C) Salt Water intrusion (D) None of these,C,"When coastal aquifers are overused, salt water from the ocean may enter the aquifer, contaminating the aquifer and making it less useful for drinking and irrigation. Salt water incursion is a problem in developed coastal regions, such as on Hawaii. "
"when a water table decline, wells must be drilled deeper.",(A) True (B) False,A,"Some aquifers are overused; people pump out more water than is replaced. As the water is pumped out, the water table slowly falls, requiring wells to be dug deeper, which takes more money and energy. Wells may go completely dry if they are not deep enough to reach into the lowered water table. Other problems may stem from groundwater overuse. Subsidence and saltwater intrusion are two of them. "
groundwater is a stable supply of water and can never be depleted.,(A) True (B) False,B,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
the water in the ogallala aquifer is mostly from the last ice age.,(A) True (B) False,A,"The Ogallala Aquifer supplies about one-third of the irrigation water in the United States. The Ogallala Aquifer is widely used by people for municipal and agricultural needs. (Figure 1.2). The aquifer is found from 30 to 100 meters deep over an area of about 440,000 square kilometers! The water in the aquifer is mostly from the last ice age. About eight times more water is taken from the Ogallala Aquifer each year than is replenished. Much of the water is used for irrigation (Figure 1.3). Click image to the left or use the URL below. URL:  Intense drought has reduced groundwater levels in the southern U.S., particularly in Texas and New Mexico. "
the dust bowl will not be repeated as long as we continue to,(A) Pump water from the Ogallala Aquifer (B) Stop farming in that region (C) Only grow crops in wet years (D) Use pesticides and herbicides to make plants grow better,A,The Dust Bowl taught people that soil could be lost by plowing and growing crops. This led to the development of new ways of farming that help protect the soil. Some of the methods are described in Figure 19.6. 
which is a source of surface water pollution?,(A) Municipal pollutants (B) Agricultural pollutants (C) Industrial pollutants (D) All of the above,D,"There are three main sources of water pollution: 1. Agriculture. 2. Industry. 3. Municipal, or community, sources. "
"more than 100,000 tanks of toxic substances are currently leaking underground.",(A) True (B) False,A,"If the source is an underground tank, the tank will be pumped dry and then dug out from the ground. If the source is a factory that is releasing toxic chemicals that are ending up in the groundwater, the factory may be required to stop the discharge. "
this much of the municipal groundwater supplies in the united states are polluted.,(A) 25% (B) 35% (C) 45% (D) 55%,C,"Groundwater is a bit safer from pollution than surface water from some types of pollution because some pollutants are filtered out by the rock and soil that water travels through as it travels through the ground or once it is in the aquifer. But rock and soil cant get out everything, depending on the type of rock and soil and on the types of pollutants. As it is, about 25% of the usable groundwater and 45% of the municipal groundwater supplies in the United States are polluted. "
what is a pollutant plume in an aquifer?,(A) Contamination that travels from the pollutant source in the direction of flow (B) Contamination that travels through an aquifer at a higher speed than the water flows (C) Water that travels down the flow gradient through a polluted region (D) None of the above,A,"When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated. In Florida, for example, more than 90% of wells have detectible contaminants and thousands have been closed. "
about 25% of groundwater in the united states is polluted.,(A) True (B) False,A,"Groundwater is a bit safer from pollution than surface water from some types of pollution because some pollutants are filtered out by the rock and soil that water travels through as it travels through the ground or once it is in the aquifer. But rock and soil cant get out everything, depending on the type of rock and soil and on the types of pollutants. As it is, about 25% of the usable groundwater and 45% of the municipal groundwater supplies in the United States are polluted. "
pollutants in an aquifer may,(A) Be filtered out by the rock or soil (B) Remain in the aquifer (C) Travel very slowly through the rock (D) All of the above,D,"When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated. In Florida, for example, more than 90% of wells have detectible contaminants and thousands have been closed. "
groundwater is often contaminated by,(A) Irrigation water (B) Underground storage tanks (C) Water seeping through landfills (D) All of these,D,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
a contaminated well will be located,(A) Only in areas where there is surface contamination (B) Only in areas that are downstream from an industrial pollutant source (C) Only in farming areas (D) Anywhere,D,"When the pollutant enters the aquifer, contamination spreads in the water outward from the source and travels in the direction that the water is moving. This pollutant plume may travel very slowly, only a few inches a day, but over time can contaminate a large portion of the aquifer. Many wells that are currently in use are contaminated. In Florida, for example, more than 90% of wells have detectible contaminants and thousands have been closed. "
groundwater that moves through the rock aquifer for years is decontaminated and drinkable.,(A) True (B) False,B,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
"fortunately, toxic chemicals that leak onto the ground remain on the ground and do not get into the groundwater supply.",(A) True (B) False,B,"Factories and power plants may pollute water with harmful substances. Many industries produce toxic chemicals. Some of the worst are arsenic, lead, and mercury. Nuclear power plants produce radioactive chemicals. They cause cancer and other serious health problems. Oil tanks and pipelines can leak. Leaks may not be noticed until a lot of oil has soaked into the ground. The oil may pollute groundwater so it is no longer fit to drink. "
human population reached its first billion in which year?,(A) 8000 BC (B) 1 (C) 1802 (D) 1961,C,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
"in 2011, the human population increased to ___________.",(A) 1 billion (B) 3 billion (C) 5 billion (D) 7 billion,D,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
"by the end of the 21st century, the human population is estimated to reach",(A) 10 billion (B) 9 billion (C) 8 billion (D) Stay the same,A,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
which can contribute to overpopulation?,(A) High mortality rate (B) Low mortality rate (C) Decreased birth rate (D) None of the above,B,"There are two different beliefs about what type of growth the human population will undergo in the future: 1. Neo-Malthusians believe that human population growth cannot continue without destroying the environment, and maybe humans themselves. 2. Cornucopians believe that the Earth can give humans a limitless amount of resources. They also believe that technology can solve problems caused by limited resources, such as lack of food. The Cornucopians believe that a larger population is good for technology and innovation. The 5-stage model above predicts that when all countries are industrialized, the human population will eventually level out. But many scientists and other Neo-Malthusians believe that humans have already gone over the Earths carrying capacity. That means, we may have already reached the maximum population size that can be supported, without destroying our resources and habitat. If this is true, then human overpopulation will lead to a lack of food and other resources. Overpopulation may also lead to increased disease, and/or war. These problems may cause the population of humans to crash. If these issues are not controlled, could the human population go extinct? Which of the above theories makes sense to you? Why? "
human population grows because,(A) Much of the human population is young and will have children (B) People are living much longer than in the past (C) More children survive to have children than in the past (D) All of these,D,"Figure 18.17 shows how the human population has grown. It grew very slowly for tens of thousands of years. Then, in the 1800s, something happened to change all that. The human population started to grow much faster. "
the rate at which the human population is growing is decreasing.,(A) True (B) False,B,The growth of the human population has started to slow down. You can see this in Figure 18.21. It may stop growing by the mid 2000s. Scientists think that the human population will peak at about 9 billion people. What will need to change for the population to stop growing then? 
limiting factors on human population in local regions include,(A) Space (B) clean air (C) clean water and food (D) b Disease (E) c Predators (F) d There are as yet no regions where human population is limited,A,"Human population growth over the past 10,000 years has been tremendous (Figure 1.1). The entire human popula- tion was estimated to be 5 million in 8000 B.C. 300 million in A.D. 1 1 billion in 1802 3 billion in 1961 7 billion in 2011 As the human population continues to grow, different factors limit population in different parts of the world. What might be a limiting factor for human population in a particular location? Space, clean air, clean water, and food to feed everyone are limiting in some locations. "
limiting factors on human population worldwide include,(A) Space (B) clean air (C) clean water and food (D) b Disease (E) c Predators (F) d There are as yet no limiting factors on human population growth worldwide,D,"Human population growth over the past 10,000 years has been tremendous (Figure 1.1). The entire human popula- tion was estimated to be 5 million in 8000 B.C. 300 million in A.D. 1 1 billion in 1802 3 billion in 1961 7 billion in 2011 As the human population continues to grow, different factors limit population in different parts of the world. What might be a limiting factor for human population in a particular location? Space, clean air, clean water, and food to feed everyone are limiting in some locations. "
"by the end of the 21st century, the human population is expected",(A) To decrease by 3 billion (B) To increase by more people than were even alive in 1960 (C) To increase by 101 billion (D) None of the above,B,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
as for future population growth,(A) The population is decreasing (B) The rate of growth of the population is decreasing (C) The rate that the rate the population is growing is decreasing (D) None of the above,C,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
which of these substances are considered hazardous waste?,(A) Chemically active materials (B) Flammable material (C) Corrosive materials (D) All of the above,D,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
"gasoline, used motor oil, battery acid and brake fluid are toxic chemicals from",(A) Medical facilities (B) Dry cleaners (C) The automotive industry (D) Paints manufacturers,C,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
paints are hazardous because they are,(A) Toxic (B) Flammable (C) Corrosive (D) A & B,D,"Lead and mercury are two chemicals that are especially toxic to humans. Lead was once a common ingredient in gasoline and paint, but it was shown to damage human brains and nervous systems. Since young children are growing rapidly, lead is especially harmful in children under the age of six (Figure 1.2). In the 1970s and 1980s, the United States government passed laws completely banning lead in gasoline and paint. Homes built before the 1970s may contain lead paint. Paint so old is likely to be peeling and poses a great threat to human health. About 200 children die every year from lead poisoning. (a) Leaded gasoline. (b) Leaded paint. Mercury is a pollutant that can easily spread around the world. Sources of mercury include volcanic eruptions, coal burning, and wastes such as batteries, electronic switches, and electronic appliances such as television sets. Like lead, mercury damages the brain and impairs nervous system function. More about the hazards of mercury pollution can be found later in this concept. "
dry cleaning chemicals are hazardous because they __________.,(A) Are flammable (B) May cause cancer in humans (C) Are corrosive (D) A & B,B,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
human blood is,(A) A medical waste (B) Messy but not a hazard (C) Flammable (D) Corrosive,A,Blood is a liquid connective tissue. It circulates throughout the body via blood vessels due to the pumping action of the heart. You couldnt survive without the approximately 4.5 to 5 liters of blood that are constantly being pumped through your blood vessels. 
what does corrosive mean?,(A) It can cause explosions (B) It destroys by chemical reactions (C) It can catch on fire (D) It is poisonous,B,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
toxic chemicals are all right if they are stored and used properly.,(A) True (B) False,A,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
if you are going to use pesticides or herbicides the more you use the more pests you kill and the better it is.,(A) True (B) False,B,"Chemical control of pests involves the use of insecticides. Insecticides, which are also known as pesticides, are most often used to kill insects. Insecticides are chemicals that kill insects. The U.S. spends $9 billion each year on pesticides. Disadvantages to using pesticides include human, fish, and honeybee poisonings, and the contamination of meat and dairy products. When choosing to use an insecticide, there are numerous points to consider. Negative effects of the pesticide should try to be minimized. Important questions to consider include the following. What is the chemicals success against the target pest? Will the insecticide provide the desired level of control of the pest? If the answer is no, other methods of control should be considered. Does the chemical have an impact on natural enemies of the pest? In large scale efforts to rid areas of mosquitoes, the insecticide used also killed the dragonfly. This effort removed a natural predator of the mosquito. This may be an unacceptable negative effect of using the insecticide. How susceptible is the crop to insect damage? If the crop is not heavily damaged, only minor pest control may be needed. This may affect the amount or type of insecticide used. How toxic is the chemical to the environment and humans? Some older insecticides are extremely poisonous. Keep in mind that users of these poisons have a community responsibility to minimize the contamination of the surrounding environment, as well as keeping animals, surrounding crops and humans safe. Does using the pesticide result in the development of resistance? If so, this can make additional use of the pesticide less effective. As the resistance will be passed to future generations of the insect (which is natural selection in action), this could be considered a negative side-effect of pesticide use. "
which of these is corrosive?,(A) Surgical gloves (B) Batteries (C) Paint (D) Dry cleaning chemicals,B,"Love Canal highlighted the problem of pollution by hazardous waste. Hazardous waste is any waste that is dangerous to the health of people or the environment. It may be dangerous because it is toxic, corrosive, flammable, or explosive. Toxic waste is poisonous. Toxic waste may cause cancer or birth defects in people. It may also harm other living things. Corrosive waste is highly reactive with other substances. Corrosive waste may cause burns or destroy other materials that it touches. Flammable waste can burn easily. It may also give off harmful fumes when it burns. Explosive waste is likely to explode. The risk of explosion may be greater if the waste is mixed with other substances. Table 19.1 shows some examples of hazardous waste. Look closely. Are any of these examples lurking around your home? Example Description Cars contain toxic fluids such as brake fluid. The fluids may also be corrosive and flammable. This photo shows one way the fluids can end up in the ground. Cars use gas and oil. These materials are toxic and flammable. They pollute the land when they leak or spill. Batteries contain toxic and corrosive materials. People often toss them in the trash, but they should be disposed of properly. Electronics, such as old computers, contain toxic chem- icals. They may be sent to landfills where the toxic materials end up in the ground. Medical waste can contain many hazards: Human body fluids may cause disease; old thermometers may contain toxic mercury; and pharmaceuticals may be toxic to people and other living things. Example Description Paints can be both toxic and flammable. Paints may spill on the ground or be thrown improperly in the trash. Chemicals are applied to farm fields and lawns. They include fertilizers, herbicides, and pesticides. Many of these chemicals are toxic to people and other animals. "
how can you can get rid of hazardous waste safely?,(A) Pour toxic liquids down the drain (B) Throw medical wastes in the trash (C) Follow the rules for each toxic material (D) All of these,C,"Cleaning products, lawn chemicals, paints, batteries, motor oil these are just some of the many hazardous materials that may be found in households. You might think that a household doesnt produce enough hazardous waste to worry about. But when you add up all the waste from all the households in a community, its a different story. A city of just 50,000 people might produce more than 40 tons of hazardous waste each year! Clearly, how households deal with hazardous waste matters. What can your family do? Reduce, reuse, recycle, or properly dispose of the wastes. 1. Reduce the amount of hazardous products you buy. For example, if you only need a quart of paint for a job, dont buy a gallon. 2. Use less hazardous products if you can. For example, clean windows with vinegar and water instead of toxic window cleaners. 3. Reuse products if its safe to do so. For example, paint thinner that has been used to clean paint brushes can be strained and reused. 4. Recycle whenever possible. For example, some service stations allow you to drop off used motor oil, car batteries, or tires for recycling. 5. Always properly dispose of hazardous waste. For example, let liquid waste evaporate before placing the container in the trash. Proper disposal depends on the waste. Many hazardous products have disposal guidelines on the label. Thats one reason why you should keep the products in their original containers. The labels also explain how to use the products safely. Follow the instructions to protect yourself and the environment. Most communities have centers for disposing of household hazardous waste (see Figure 19.11). Do you know how to dispose of hazardous waste in your community? "
only this much of the solar radiation reaches the surface of the earth.,(A) Three-fourths (B) Half (C) One-fourth (D) Two-thirds,B,"Most of the energy that reaches the Earths surface comes from the Sun (Figure 1.1). About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths. "
the equatorial regions albedo is low because the region is heavily forested.,(A) True (B) False,A,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
the amount of incoming solar radiation is the same at all latitudes.,(A) True (B) False,B,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
night and day each last 6 months in the polar regions.,(A) True (B) False,A,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
about 90% of the solar radiation that strikes the top of the atmosphere is filtered out before it reaches the ground.,(A) True (B) False,B,"About half of the solar radiation that strikes the top of the atmosphere is filtered out before it reaches the ground. This energy can be absorbed by atmospheric gases, reflected by clouds, or scattered. Scattering occurs when a light wave strikes a particle and bounces off in some other direction. About 3% of the energy that strikes the ground is reflected back into the atmosphere. The rest is absorbed by rocks, soil, and water and then radiated back into the air as heat. These infrared wavelengths can only be seen by infrared sensors. Click image to the left or use the URL below. URL: "
what happens to the suns radiation that strikes the ground?,(A) It is reradiated as heat (B) It is reflected back into the atmosphere (C) It is absorbed by rocks and soil (D) All of these,D,"About half of the solar radiation that strikes the top of the atmosphere is filtered out before it reaches the ground. This energy can be absorbed by atmospheric gases, reflected by clouds, or scattered. Scattering occurs when a light wave strikes a particle and bounces off in some other direction. About 3% of the energy that strikes the ground is reflected back into the atmosphere. The rest is absorbed by rocks, soil, and water and then radiated back into the air as heat. These infrared wavelengths can only be seen by infrared sensors. Click image to the left or use the URL below. URL: "
why is the albedo in the polar regions high?,(A) The polar regions have a lot of snow and ice (B) The polar regions have a lot of vegetation (C) The polar regions have a lot of open dirt and rock (D) All of these,A,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
where is the number of day and night hours closest to equal all year?,(A) The Equator (B) The North Pole (C) The South Pole (D) The tropic of cancer and the tropic of Capricorn,A,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
why isnt earths heat budget balanced?,(A) Because the amount of outgoing heat is greater than the amount incoming heat (B) Because the amount of solar radiation is not equal at different latitudes (C) Because the amount of incoming heat is greater than the amount outgoing heat (D) Because the amount of solar radiation is the same at different latitudes,C,"Because solar energy continually enters Earths atmosphere and ground surface, is the planet getting hotter? The answer is no (although the next section contains an exception), because energy from Earth escapes into space through the top of the atmosphere. If the amount that exits is equal to the amount that comes in, then average global temperature stays the same. This means that the planets heat budget is in balance. What happens if more energy comes in than goes out? If more energy goes out than comes in? To say that the Earths heat budget is balanced ignores an important point. The amount of incoming solar energy is different at different latitudes. Where do you think the most solar energy ends up and why? Where does the least solar energy end up and why? See the Table 1.1. Equatorial Region Polar Regions Day Length Nearly the same all year Night 6 months Sun Angle High Solar Radiation High Albedo Low Low Low High Note: Colder temperatures mean more ice and snow cover the ground, making albedo relatively high. The difference in solar energy received at different latitudes drives atmospheric circulation. "
"if more heat enters the earth system than leaves it, then",(A) The planet will cool (B) More heat will need to leave the system (C) More heat will need to enter the system (D) The planet will warm,D,"Because solar energy continually enters Earths atmosphere and ground surface, is the planet getting hotter? The answer is no (although the next section contains an exception), because energy from Earth escapes into space through the top of the atmosphere. If the amount that exits is equal to the amount that comes in, then average global temperature stays the same. This means that the planets heat budget is in balance. What happens if more energy comes in than goes out? If more energy goes out than comes in? To say that the Earths heat budget is balanced ignores an important point. The amount of incoming solar energy is different at different latitudes. Where do you think the most solar energy ends up and why? Where does the least solar energy end up and why? See the Table 1.1. Equatorial Region Polar Regions Day Length Nearly the same all year Night 6 months Sun Angle High Solar Radiation High Albedo Low Low Low High Note: Colder temperatures mean more ice and snow cover the ground, making albedo relatively high. The difference in solar energy received at different latitudes drives atmospheric circulation. "
the transfer of energy between two objects by electromagnetic waves.,(A) Radiation (B) Conduction (C) Convection (D) Connection,A,"Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electro- magnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation. Electromagnetic waves can transfer energy through matter or across empty space. Click image to the left or use the URL below. URL:  Q: How do microwaves transfer energy inside a microwave oven? A: They transfer energy through the air inside the oven to the food. "
heat moving from more heat to areas of less heat by direct contact.,(A) Radiation (B) Conduction (C) Convection (D) Connection,B,"Heat moves in the atmosphere the same way it moves through the solid Earth or another medium. What follows is a review of the way heat flows, but applied to the atmosphere. Radiation is the transfer of energy between two objects by electromagnetic waves. Heat radiates from the ground into the lower atmosphere. In conduction, heat moves from areas of more heat to areas of less heat by direct contact. Warmer molecules vibrate rapidly and collide with other nearby molecules, transferring their energy. In the atmosphere, conduction is more effective at lower altitudes, where air density is higher. This transfers heat upward to where the molecules are spread further apart or transfers heat laterally from a warmer to a cooler spot, where the molecules are moving less vigorously. Heat transfer by movement of heated materials is called convection. Heat that radiates from the ground initiates convection cells in the atmosphere (Figure 1.1). Click image to the left or use the URL below. URL: "
"conduction is more effective at higher altitudes, where air density is lower.",(A) True (B) False,B,"Altitude is height above sea level. The density of air decreases with height. There are two reasons. At higher altitudes, there is less air pushing down from above. Also, gravity is weaker farther from Earths center. So at higher altitudes, air molecules can spread out more. Air density decreases. You can see this in Figure 15.4. "
solar energy coming through space is transferred by,(A) Conduction (B) Convection (C) Connection (D) Radiation,D,"Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Suns energy travels through space by radiation. After sunlight heats the planets surface, some heat radiates back into the atmosphere. "
what drives the water cycle?,(A) The Earth’s core (B) The Moon (C) The Sun (D) Greenhouse gases,C,"The Sun, many millions of kilometers away, provides the energy that drives the water cycle. Our nearest star directly impacts the water cycle by supplying the energy needed for evaporation. "
the suns rays strike the surface most directly at the equator.,(A) True (B) False,A,"Different parts of Earths surface receive different amounts of sunlight. You can see this in Figure 15.10. The Suns rays strike Earths surface most directly at the equator. This focuses the rays on a small area. Near the poles, the Suns rays strike the surface at a slant. This spreads the rays over a wide area. The more focused the rays are, the more energy an area receives and the warmer it is. "
a spoon getting warmed by boiling water is an example of this.,(A) Radiation (B) Conduction (C) Convection (D) Connection,B,"Figure 18.3 illustrates an example of thermal energy transfer. Before the spoon was put into the steaming hot coffee, it was cool to the touch. Once in the coffee, the spoon heated up quickly. The fast-moving particles of the coffee transferred some of their energy to the slower-moving particles of the spoon. The spoon particles started moving faster and became warmer, causing the temperature of the spoon to rise. Because the coffee particles lost some of their kinetic energy to the spoon particles, the coffee particles started to move more slowly. This caused the temperature of the coffee to fall. Before long, the coffee and spoon had the same temperature. "
when air gets warmer,(A) It goes upward (B) Molecules move faster (C) Molecules spread apart (D) All of the above,D,"When a warm air mass runs into a cold air mass it creates a warm front. This is shown in Figure 16.8. The warm air mass is moving faster than the cold air mass, so it flows up over the cold air mass. As the warm air rises, it cools, resulting in clouds and sometimes light precipitation. Warm fronts move slowly and cover a wide area. After a warm front passes, the warm air mass behind it brings warmer temperatures. The warm air is also likely to be more humid. "
why do the poles receive less solar radiation than the equator?,(A) The sun’s rays strike obliquely and only during the summer (B) The sun’s rays strike directly but only during summer (C) The sun’s rays strike obliquely in the winter and directly in the summer (D) None of the above,A,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
what causes a heat wave?,(A) A high pressure cell sits over a region (B) A high pressure zone keeps the jet stream from moving south as it normally does (C) Solar radiation increases due to solar storms (D) A & B,D,A high pressure cell sitting over a region with no movement is the likely cause of a heat wave. What do you think caused the heat wave in the image below (Figure 1.1)? A high pressure zone kept the jet stream further north than normal for August. A heat wave over the United States as in- dicated by heat radiated from the ground. The bright yellow areas are the hottest and the blue and white are coolest. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: 
heat waves have increased in frequency and duration in recent years.,(A) True (B) False,A,"A heat wave is different depending on its location. According to the World Meteorological Organization, a region is in a heat wave if it has more than five consecutive days of temperatures that are more than 9 F (5 C) above average. Heat waves have increased in frequency and duration in recent years. The summer 2011 North American heat wave brought record temperatures across the Midwestern and Eastern United States. Many states and localities broke records for temperatures and for most days above 100 F. "
a region is having a heat wave when it is experiencing more than _____ consecutive days of temperatures more than _____ above the average.,(A) 3; 3oF (17oC) (B) 5; 9oF (5oC) (C) 10; 12oF (67oC) (D) 7; 15oF (83oC),B,"A heat wave is different depending on its location. According to the World Meteorological Organization, a region is in a heat wave if it has more than five consecutive days of temperatures that are more than 9 F (5 C) above average. Heat waves have increased in frequency and duration in recent years. The summer 2011 North American heat wave brought record temperatures across the Midwestern and Eastern United States. Many states and localities broke records for temperatures and for most days above 100 F. "
wildfires are increasingly common in the western united states due to an extended,(A) Drought (B) Heat wave (C) Monsoon season (D) A & B,A,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
"three months with average daily high temperatures above 100of is normal for phoenix, arizona, but six days of 100of temperatures in portland, oregon is a heat wave.",(A) True (B) False,A,"A heat wave is different depending on its location. According to the World Meteorological Organization, a region is in a heat wave if it has more than five consecutive days of temperatures that are more than 9 F (5 C) above average. Heat waves have increased in frequency and duration in recent years. The summer 2011 North American heat wave brought record temperatures across the Midwestern and Eastern United States. Many states and localities broke records for temperatures and for most days above 100 F. "
droughts in the 1930s were a major factor in causing this event.,(A) The Great Depression (B) World War II (C) The Dust Bowl (D) The Green Revolution,C,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
"people survive in phoenix, arizona in intense heat because they are hardier than people in other locations.",(A) True (B) False,B,"Each organism has the ability to survive in a specific environment. Dry desert environments are difficult to live in. Desert plants have special stems and leaves to conserve water. Animals have other ways to live in the desert. The Namib Desert receives only 1.5 inches of rainfall each year. The Namib Desert beetle lives there. How do the beetles get enough water to survive? Early morning fog deposits water droplets. The droplets collect on a beetles wings and back. The beetle tilts its rear end up. When the droplet is heavy enough, it slides forward. It lands in the beetles mouth. There are many other environments that need unique approaches for survival (Figure 12.10). "
what are some consequences of droughts?,(A) Soil loss (B) Trees in forests die (C) Ecosystems damaged (D) All of these,D,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
"more people die in heat waves than in blizzards, tornadoes or hurricanes.",(A) True (B) False,A,"An individual tornado strikes a small area, but it can destroy everything in its path. Most injuries and deaths from tornadoes are caused by flying debris (Figure 1.3). In the United States an average of 90 people are killed by tornadoes each year. The most violent two percent of tornadoes account for 70% of the deaths by tornadoes. "
hot springs are cooler than geysers.,(A) True (B) False,B,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
hot springs or geyers are created when,(A) Water comes into contact with hot rock (B) Water enters and leaves a magma chamber (C) Water travels along an earthquake fault (D) Water bubbles up from the mantle,A,Water sometimes comes into contact with hot rock. The water may emerge at the surface as either a hot spring or a geyser. 
bison use the hot springs in yellowstone to stay warm in the winter because the hot springs do not freeze.,(A) True (B) False,A,"Geysers are also created by water that is heated beneath the Earths surface, but geysers do not bubble to the surface they erupt. When water is both superheated by magma and flows through a narrow passageway underground, the environment is ideal for a geyser. The passageway traps the heated water underground, so that heat and pressure can build. Eventually, the pressure grows so great that the superheated water bursts out onto the surface to create a geyser. Figure 1.2. Conditions are right for the formation of geysers in only a few places on Earth. Of the roughly 1,000 geysers worldwide, about half are found in the United States. Yellowstone isnt the only place in the continental U.S. with hot springs and geysers. Hot Creek in California deserves its name; Like Yellowstone, it is above a supervolcano. Click image to the left or use the URL below. URL:  Castle Geyser is one of the many gey- sers at Yellowstone National Park. Castle erupts regularly, but not as frequently or predictably as Old Faithful. "
this results when water that is trapped becomes superheated until finally the pressure builds enough for it to break the seal of the earths crust.,(A) An earthquake (B) A hot spring (C) A geyser (D) A hot pool,C,"Heated groundwater may become trapped in spaces within rocks. Pressure builds up as more water seeps into the spaces. When the pressure becomes great enough, the water bursts out of the ground at a crack or weak spot. This is called a geyser. When the water erupts from the ground, the pressure is released. Then more water collects and the pressure builds up again. This leads to another eruption. Old Faithful is the best-known geyser in the world. You can see a picture of it in Figure 13.17. The geyser erupts faithfully every 90 minutes, day after day. During each eruption, it may release as much as 30,000 liters of water! "
geysers,(A) Are water that bubbles from the ground (B) similar to hot springs (C) b Erupt because superheated water is trapped until the pressure builds enough for the (D) c Are found in most states in the continental US (E) d Erupt frequently and on a predictable schedule,B,"Geysers are also created by water that is heated beneath the Earths surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser. There are only a few areas in the world where the conditions are right for the formation of geysers. Only about 1,000 geysers exist worldwide. About half of them are in the United States. The most famous geyser is Old Faithful at Yellowstone National Park (Figure 8.23). It is rare for a geyser to erupt so regularly, which is why Old Faithful is famous. "
"as far as the worlds geysers go,",(A) Nearly all are found in Iceland (B) Nearly all are found in the Hawaiian Islands (C) Half are found in the East African Rift (D) Half are found in the United States,D,"Geysers are also created by water that is heated beneath the Earths surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser. There are only a few areas in the world where the conditions are right for the formation of geysers. Only about 1,000 geysers exist worldwide. About half of them are in the United States. The most famous geyser is Old Faithful at Yellowstone National Park (Figure 8.23). It is rare for a geyser to erupt so regularly, which is why Old Faithful is famous. "
old faithful geyser is noteworthy for the frequency and predictability of its eruptions.,(A) True (B) False,A,"Heated groundwater may become trapped in spaces within rocks. Pressure builds up as more water seeps into the spaces. When the pressure becomes great enough, the water bursts out of the ground at a crack or weak spot. This is called a geyser. When the water erupts from the ground, the pressure is released. Then more water collects and the pressure builds up again. This leads to another eruption. Old Faithful is the best-known geyser in the world. You can see a picture of it in Figure 13.17. The geyser erupts faithfully every 90 minutes, day after day. During each eruption, it may release as much as 30,000 liters of water! "
hot springs are only found in the tectonically active western united states.,(A) True (B) False,A,"The second photo in the introduction is of a geyser at Yellowstone National Park in Wyoming. Yellowstone is in the western U.S. but is inland from the plate boundaries offshore. Hotspot magmas rarely penetrate through thick continental crust, so hotspot activity on continents is rare. One exception is the Yellowstone hotspot (Figure 1.3). Volcanic activity above the Yellowstone hotspot on can be traced from 15 million years ago to its present location on the North American Plate. The ages of volcanic activity attributed to the Yellowstone hotspot. Click image to the left or use the URL below. URL: "
at least two of the hot spring areas in the continental u.s. are,(A) Above supervolcanoes (B) Found in the Rocky Mountains (C) Near subduction zones (D) The hottest hot springs in the world,A,"The second photo in the introduction is of a geyser at Yellowstone National Park in Wyoming. Yellowstone is in the western U.S. but is inland from the plate boundaries offshore. Hotspot magmas rarely penetrate through thick continental crust, so hotspot activity on continents is rare. One exception is the Yellowstone hotspot (Figure 1.3). Volcanic activity above the Yellowstone hotspot on can be traced from 15 million years ago to its present location on the North American Plate. The ages of volcanic activity attributed to the Yellowstone hotspot. Click image to the left or use the URL below. URL: "
the heat that creates the geysers at yellowstone national park is due to,(A) Subduction of an oceanic plate beneath the area (B) Heat from the inner core (C) A hotspot beneath the area (D) Solar energy,C,"Geysers are also created by water that is heated beneath the Earths surface, but geysers do not bubble to the surface they erupt. When water is both superheated by magma and flows through a narrow passageway underground, the environment is ideal for a geyser. The passageway traps the heated water underground, so that heat and pressure can build. Eventually, the pressure grows so great that the superheated water bursts out onto the surface to create a geyser. Figure 1.2. Conditions are right for the formation of geysers in only a few places on Earth. Of the roughly 1,000 geysers worldwide, about half are found in the United States. Yellowstone isnt the only place in the continental U.S. with hot springs and geysers. Hot Creek in California deserves its name; Like Yellowstone, it is above a supervolcano. Click image to the left or use the URL below. URL:  Castle Geyser is one of the many gey- sers at Yellowstone National Park. Castle erupts regularly, but not as frequently or predictably as Old Faithful. "
collections of fossils are known as,(A) Fossil collections (B) Fossil assemblages (C) Ecosystem collections (D) Ecosystem assemblages,B,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
nicholas steno in 1666 said that fossils were once part of living creatures because fossils from far inland looked like the teeth of a freshly caught great white shark.,(A) True (B) False,A,"It wasnt always known that fossils were parts of living organisms. In 1666, a young doctor named Nicholas Steno dissected the head of an enormous great white shark that had been caught by fisherman near Florence, Italy. Steno was struck by the resemblance of the sharks teeth to fossils found in inland mountains and hills (Figure 1.1). Most people at the time did not believe that fossils were once part of living creatures. Authors in that day thought that the fossils of marine animals found in tall mountains, miles from any ocean could be explained in one of two ways: The shells were washed up during the Biblical flood. (This explanation could not account for the fact that fossils were not only found on mountains, but also within mountains, in rocks that had been quarried from deep below Earths surface.) The fossils formed within the rocks as a result of mysterious forces. But for Steno, the close resemblance between fossils and modern organisms was impossible to ignore. Instead of invoking supernatural forces, Steno concluded that fossils were once parts of living creatures. Fossil Shark Tooth (left) and Modern Shark Tooth (right). "
marine fossils found in tall mountains were,(A) Once part of living creatures (B) Washed up during the biblical flood (C) Formed within the rocks as the result of mysterious forces (D) Of unknown origin,A,"Fossils give clues about major geological events. Fossils can also give clues about past climates. Fossils of ocean animals are found at the top of Mt. Everest. Mt. Everest is the highest mountain on Earth. These fossils show that the area was once at the bottom of a sea. The seabed was later uplifted to form the Himalaya mountain range. An example is shown in the Figure 11.4. Fossils of plants are found in Antarctica. Currently, Antarctica is almost completely covered with ice. The fossil plants show that Antarctica once had a much warmer climate. "
almost every single organism that has ever lived became a fossil.,(A) True (B) False,B,"Of all the organisms that ever lived, only a tiny number became fossils. Still, scientists learn a lot from fossils. Fossils are our best clues about the history of life on Earth. "
which will more likely result in a fossil?,(A) A zebra is attacked by a pride of lions and its meat is all eaten (B) An insect dies in a grassy area (C) Hard shelled marine organisms die and are rapidly buried by sediment (D) All of the above,C,"Its very unlikely that any given organism will become a fossil. The remains of many organisms are consumed. Remains also may be broken down by other living things or by the elements. Hard parts, such as bones, are much more likely to become fossils. But even they rarely last long enough to become fossils. Organisms without hard parts are the least likely to be fossilized. Fossils of soft organisms, from bacteria to jellyfish, are very rare. "
a ______ fossil is left behind when the soft parts have decayed away.,(A) Hard (B) Bone (C) Trace (D) Body,D,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
"_______ fossils are burrows, tracks, or fossilized coprolites (feces).",(A) Soft (B) Bone (C) Body (D) Trace,D,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
the la brea tar pits in los angeles is an example of an unusual circumstance in which a variety of fossils are preserved.,(A) True (B) False,A,"Unusual circumstances may lead to the preservation of a variety of fossils, as at the La Brea Tar Pits in Los Angeles, California. Although the animals trapped in the La Brea Tar Pits probably suffered a slow, miserable death, their bones were preserved perfectly by the sticky tar. (Figure 1.7). Artists concept of animals surrounding the La Brea Tar Pits. In spite of the difficulties of preservation, billions of fossils have been discovered, examined, and identified by thousands of scientists. The fossil record is our best clue to the history of life on Earth, and an important indicator "
soft parts of an organism are never preserved so life before the evolution of hard parts is a complete mystery.,(A) True (B) False,B,"The soft parts of organisms almost always decompose quickly after death. Thats why most fossils consist of hard parts such as bones. Its rare even for hard parts to remain intact long enough to become fossils. Fossils form when water seeps through the remains and deposits minerals in them. The remains literally turn to stone. Remains are more likely to form fossils if they are covered quickly by sediments. Once in a while, remains are preserved almost unchanged. For example, they may be frozen in glaciers. Or they may be trapped in tree resin that hardens to form amber. Thats what happened to the wasp in Figure 7.8. The wasp lived about 20 million years ago, but even its fragile wings have been preserved by the amber. "
this ocean current helps to moderate the temperature in europe.,(A) The Gulf Stream (B) The Labrador Current (C) El Nino (D) The Humboldt Current,A,"The temperature of the water offshore influences the temperature of a coastal location, particularly if the winds come off the sea. The cool waters of the California Current bring cooler temperatures to the California coastal region. Coastal upwelling also brings cold, deep water up to the ocean surface off of California, which contributes to the cool coastal temperatures. Further north, in southern Alaska, the upwelling actually raises the temperature of the surrounding land because the ocean water is much warmer than the land. The important effect of the Gulf Stream on the climate of northern Europe is described in the chapter Water on Earth. "
water in the gulf stream travels along the equator and is cooled as it goes.,(A) True (B) False,B,"Surface currents play an enormous role in Earths climate. Even though the Equator and poles have very different climates, these regions would have more extremely different climates if ocean currents did not transfer heat from the equatorial regions to the higher latitudes. The Gulf Stream is a river of warm water in the Atlantic Ocean, about 160 kilometers wide and about a kilometer deep. Water that enters the Gulf Stream is heated as it travels along the Equator. The warm water then flows up the east coast of North America and across the Atlantic Ocean to Europe (see opening image). The energy the Gulf Stream transfers is enormous: more than 100 times the worlds energy demand. The Gulf Streams warm waters raise temperatures in the North Sea, which raises the air temperatures over land between 3 to 6 C (5 to 11 F). London, U.K., for example, is at about six degrees further south than Quebec, Canada. However, Londons average January temperature is 3.8 C (38 F), while Quebecs is only -12 C (10 F). Because air traveling over the warm water in the Gulf Stream picks up a lot of water, London gets a lot of rain. In contrast, Quebec is much drier and receives its precipitation as snow. Quebec City, Quebec in winter. Click image to the left or use the URL below. URL: "
ocean currents transfer energy from the,(A) Northern Hemisphere to the Southern Hemisphere (B) Southern Hemisphere to the Northern Hemisphere (C) Equatorial region to the Polar Regions (D) Polar Regions to the equatorial region,C,"Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earths surface, through water in the oceans, and through air in the atmosphere. Convection currents in the atmosphere create winds. You can see one way this happens in the Figure 1.2. The land heats up and cools off faster than the water because it has lower specific heat. Therefore, the land gets warmer during the day and cooler at night than the water does. During the day, warm air rises above the land and cool air from the water moves in to take its place. During the night, the opposite happens. Warm air rises above the water and cool air from the land moves out to take its place. Q: During the day, in which direction is thermal energy of the air transferred? In which direction is it transferred during the night? A: During the day, thermal energy is transferred from the air over the land to the air over the water. During the night, thermal energy is transferred in the opposite direction. "
which of the following is not true about the gulf stream?,(A) It is an enormous river of warm water (B) It raises temperatures in the North Sea and in the air over London (C) It is easy to visualize from space in temperature readings (D) It has a large temperature affect on the eastern United States and Canada,D,"Surface currents play an enormous role in Earths climate. Even though the Equator and poles have very different climates, these regions would have more extremely different climates if ocean currents did not transfer heat from the equatorial regions to the higher latitudes. The Gulf Stream is a river of warm water in the Atlantic Ocean, about 160 kilometers wide and about a kilometer deep. Water that enters the Gulf Stream is heated as it travels along the Equator. The warm water then flows up the east coast of North America and across the Atlantic Ocean to Europe (see opening image). The energy the Gulf Stream transfers is enormous: more than 100 times the worlds energy demand. The Gulf Streams warm waters raise temperatures in the North Sea, which raises the air temperatures over land between 3 to 6 C (5 to 11 F). London, U.K., for example, is at about six degrees further south than Quebec, Canada. However, Londons average January temperature is 3.8 C (38 F), while Quebecs is only -12 C (10 F). Because air traveling over the warm water in the Gulf Stream picks up a lot of water, London gets a lot of rain. In contrast, Quebec is much drier and receives its precipitation as snow. Quebec City, Quebec in winter. Click image to the left or use the URL below. URL: "
the equator and poles would have even more different climates if it werent for surface ocean currents.,(A) True (B) False,A,Ocean water moves in predictable ways along the ocean surface. Surface currents can flow for thousands of kilometers and can reach depths of hundreds of meters. These surface currents do not depend on weather; they remain unchanged even in large storms because they depend on factors that do not change. Surface currents are created by three things: global wind patterns the rotation of the Earth the shape of the ocean basins Surface currents are extremely important because they distribute heat around the planet and are a major factor influencing climate around the globe. 
"quebec, canada and london, england have different climates because they are at different latitudes.",(A) True (B) False,B,"Even places at the same latitude may have different climates if one is on a coast and one is inland. On the coast, the climate is influenced by warm moist air from the ocean. A coastal climate is usually mild. Summers arent too hot, and winters arent too cold. Precipitation can be high due to the moisture in the air. Farther inland, the climate is influenced by cold or hot air from the land. This air may be dry because it comes from over land. An inland climate is usually more extreme. Winters may be very cold, and summers may be very hot. Precipitation can be low. "
the energy in the gulf stream could supply the world with energy 100-times over.,(A) True (B) False,A,"With the race on to reduce global warming and fossil fuel dependency, experts in alternative energy see a bright future for renewable resources like wind, solar, hydro-power and geothermal energy. QUEST and Climate Watch team up to look at the ""Smart Grid"" of the future and how it might be improved to more cleanly and efficiently keep the lights on in California. For more information on the ""Smart Grid"", see http://science.kqed.org/quest/video/clim MEDIA Click image to the left or use the URL below. URL: "
what would happen to the climate of northern europe if the gulf stream stopped flowing?,(A) It would remain the same (B) It would get much colder and would snow instead of rain (C) It is impossible to know (D) It would get much colder with more rain,B,"Surface currents play an enormous role in Earths climate. Even though the Equator and poles have very different climates, these regions would have more extremely different climates if ocean currents did not transfer heat from the equatorial regions to the higher latitudes. The Gulf Stream is a river of warm water in the Atlantic Ocean, about 160 kilometers wide and about a kilometer deep. Water that enters the Gulf Stream is heated as it travels along the Equator. The warm water then flows up the east coast of North America and across the Atlantic Ocean to Europe (see opening image). The energy the Gulf Stream transfers is enormous: more than 100 times the worlds energy demand. The Gulf Streams warm waters raise temperatures in the North Sea, which raises the air temperatures over land between 3 to 6 C (5 to 11 F). London, U.K., for example, is at about six degrees further south than Quebec, Canada. However, Londons average January temperature is 3.8 C (38 F), while Quebecs is only -12 C (10 F). Because air traveling over the warm water in the Gulf Stream picks up a lot of water, London gets a lot of rain. In contrast, Quebec is much drier and receives its precipitation as snow. Quebec City, Quebec in winter. Click image to the left or use the URL below. URL: "
"the gulf stream flows up the eastern u.s., but it has a much greater effect on the climate of northern europe. why?",(A) The prevailing winds at those latitudes are from east to west (B) When it gets to Eurasia (C) it meets the North Sea and mixes with that colder water (D) c The prevailing winds at those latitudes are from west to east (E) d None of these,C,"Large ocean currents can have a big impact on the climate of nearby coasts. The Gulf Stream, for example, carries warm water from near the equator up the eastern coast of North America. Look at the map in Figure 14.16. It shows how the Gulf Stream warms both the water and land along the coast. "
london gets a lot of rain because,(A) The Gulf Stream warms the air above it so that it can hold more moisture (B) which it drops (C) b The Gulf Stream mixes with the Labrador Current (D) which causes warm and cold air to mix and precipitate (E) c The warm air above the British Isles is hit by the cold air of the North Atlantic and causes there to be rain (F) d None of these,A,"Rainfall varies around the globe. About 40 percent of the land gets very little rain. About the same percentage of the worlds people dont have enough water. You can compare global rainfall with the worldwide freshwater supply at the two URLs below. Drier climates generally have less water for people to use. In some places, people may have less water available to them for an entire year than many Americans use in a single day! How much water is there where you live? Global rainfall: http://commons.wikimedia.org/wiki/File:World_precip_annual.png Freshwater supply: http://commons.wikimedia.org/wiki/File:2006_Global_Water_Availability.svg "
________ and modern humans had a common ancestor as recently as about 7 million years ago.,(A) Bipedals (B) Hominids (C) Apes (D) Neanderthals,C,"Humans evolved from primates, and apes and humans have a primate common ancestor. About 7 million years ago, chimpanzees (our closest living relatives) and humans shared their last common ancestor. "
humans evolved during the later,(A) Mesozoic (B) Cenozoic (C) Paleozoic (D) Humanzoic,B,"Humans evolved during the later Cenozoic. New fossil discoveries alter the details of what we know about the evolution of modern humans, but the major evolutionary path is well understood. "
humans evolved directly from chimpanzees.,(A) True (B) False,B,"Humans evolved from primates, and apes and humans have a primate common ancestor. About 7 million years ago, chimpanzees (our closest living relatives) and humans shared their last common ancestor. "
the advantages of being bipedal include the ability to,(A) See over grasses (B) Use hands and arms for hunting (C) Better tend for your young (D) All of the above,D,"Birds are four-limbed, endothermic vertebrates. The upper pair of limbs are wings that most birds use for flying. The lower pair of limbs are legs with feet that birds use for walking. Because birds walk on two legs, they are called bipedal. (Humans are bipedal too.) Birds also have feathers and beaks, and they produce amniotic eggs. Of all vertebrate classes, birds are the most numerous, even though they evolved most recently. Why have birds been so successful? The answer is flight. Being able to fly opened up a whole new world to birds: the world of the air above the land and water. Other than insects, virtually no other animals can inhabit the airy world. Flying is a sure-fire way to escape from all but the quickest nonflying predators. Flying also gives birds a good view for finding food and mates. "
"homo sapiens evolved about 200,000 years ago.",(A) True (B) False,A,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
homo erectus,(A) Was still walking on all fours (B) Developed the first stone tools about 25 million years ago (C) Began to develop culture (D) All of these,C,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
"the human ancestor, ______________, lived between 3.9 and 2.9 million years ago, was bipedal and had a brain larger than a chimp.",(A) Ardipithecus (B) Australopithecus afarensis (C) Homo erectus (D) Homo sapiens,B,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
modern humans are in the species,(A) Homo sapiens (B) Homo erectus (C) Homo neanderthalensis (D) None of the above,A,"Humans evolved during the later Cenozoic. New fossil discoveries alter the details of what we know about the evolution of modern humans, but the major evolutionary path is well understood. "
"scientists are certain that our ancestors had a spiritual life at around 32,000 years ago as evidenced by their carved stone figurines.",(A) True (B) False,B,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
"during the ice ages, humans walked over ________ from the old world to the new world.",(A) Water bridges (B) The Bering Strait (C) The Atlantic land bridge (D) The water,B,"During the Quaternary Period, the climate cooled. This caused a series of ice ages. Glaciers advanced southward from the North Pole. They reached as far south as Chicago and New York City. Sea levels fell because so much water was frozen in glaciers. This exposed land bridges between continents. The land bridges allowed land animals to move to new areas. Some mammals adapted to the cold by evolving very large size and thick fur. An example is the woolly mammoth, shown in Figure 7.25. Other mammals moved closer to the equator. Those that couldnt adapt or move went extinct, along with many plants. The last ice age ended about 12,000 years ago. By then, our own species, Homo sapiens, had evolved. After that, we were eyewitnesses to the story of life. As a result, the recent past is less of a mystery than the billions of years before it. "
igneous rocks are classified by their,(A) Composition and density (B) Density and texture (C) Texture and composition (D) None of these,C,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
what are the properties of mafic rock?,(A) High density (B) Dark color (C) Contains olivine (D) All of the above,D,Different factors play into the composition of a magma and the rock it produces. 
ultramafic igneous rocks have the lowest amount of silica of any igneous rocks.,(A) True (B) False,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
the composition of an igneous rock is related to the rocks,(A) Crystal size (B) Density (C) Location where it formed (D) All of these,B,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
the mineral quartz is likely to be found in __________ rocks.,(A) felsic (B) intermediate (C) mafic (D) ultramafic,A,"The roughly 1,000 silicate minerals make up over 90% of Earths crust. Silicates are by far the largest mineral group. Feldspar and quartz are the two most common silicate minerals. Both are extremely common rock-forming minerals. The basic building block for all silicate minerals is the silica tetrahedron, which is illustrated in Figure 1.1. To create the wide variety of silicate minerals, this pyramid-shaped structure is often bound to other elements, such as calcium, iron, and magnesium. Silica tetrahedrons combine together in six different ways to create different types of silicates (Figure 1.2). Tetrahe- drons can stand alone, form connected circles called rings, link into single and double chains, form large flat sheets of pyramids, or join in three dimensions. One silicon atom bonds to four oxygen atoms to form a silica tetrahedron. The different ways that silica tetrahedrons can join together cause these two minerals to look very different. "
granite is a type of felsic rock.,(A) True (B) False,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
which of these minerals or rocks are ultramafic?,(A) Komatiite (B) Olivine (C) Peridotite (D) All of the above,D,"Scientists know that the mantle is made of rock based on evidence from seismic waves, heat flow, and meteorites. The properties fit the ultramafic rock peridotite, which is made of the iron- and magnesium-rich silicate minerals (Figure 1.1). Peridotite is rarely found at Earths surface. "
"if you were trying to identify a light colored igneous rock with tiny crystals, you would look at these rock types",(A) Mafic Intrusive (B) Mafic extrusive (C) Felsic intrusive (D) Felsic extrusive,D,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
granite and andesite have the same composition but different texture.,(A) True (B) False,B,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
gabbro and basalt have the same composition but different texture.,(A) True (B) False,A,"Oceanic crust is composed of mafic magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro (Figure 1.1). Gabbro from ocean crust. The gabbro is deformed because of intense faulting at the eruption site. Sediments, primarily mud and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore, where it comes off the continents in rivers and on wind currents. The oceanic crust is relatively thin and lies above the mantle. The cross section of oceanic crust in the Figure 1.2 shows the layers that grade from sediments at the top to extrusive basalt lava, to the sheeted dikes that feed lava to the surface, to deeper intrusive gabbro, and finally to the mantle. "
temperature increases are predicted to happen,(A) Uniformly around the globe (B) In the polar regions more than in the equatorial regions (C) Only in the polar regions (D) Only in the equatorial regions,B,"Computer models are used to predict the effects of greenhouse gas increases on climate for the planet as a whole and also for specific regions. If nothing is done to control greenhouse gas emissions and they continue to increase at current rates, the surface temperature of the Earth can be expected to increase between 0.5o C and 2.0o C (0.9o F and 3.6o F) by 2050 and between 2o and 4.5o C (3.5o and 8o F) by 2100, with CO2 levels over 800 parts per million (ppm). Global CO2 emissions are rising rapidly. The industrial revolution began about 1850 and industrialization has been ac- celerating. On the other hand, if severe limits on CO2 emissions begin soon, temperatures could rise less than 1.1o C (2o F) by 2100. Click image to the left or use the URL below. URL:  Whatever the temperature increase, it will not be uniform around the globe. A rise of 2.8o C (5o F) would result in 0.6o to 1.2o C (1o to 2o F) at the Equator, but up to 6.7o C (12o F) at the poles. So far, global warming has affected the North Pole more than the South Pole, but temperatures are still increasing at Antarctica (Figure 1.2). "
"if nothing is done to shift society away from using fossil fuels,",(A) The rate of increase in emissions will continue to increase (B) The rate of increase in emissions will slow down (C) The emissions rate will remain the same (D) The emissions rate will begin to decrease,A,"We can reduce our use of fossil fuels in several ways: Conserve fossil fuels. For example, turning out lights when we arent using them saves electricity. Why does this help? A lot of the electricity we use comes from coal-burning power plants. Use fossil fuels more efficiently. For example, driving a fuel-efficient car lets you go farther on each gallon of gas. This can add up to a big savings in fossil fuel use. Change to alternative energy sources that produce little or no air pollution. For example, hybrid cars run on electricity that would be wasted during braking. These cars use gas only as a backup fuel. As a result, they produce just 10 percent of the air pollution produced by cars that run only on gas. Cars that run on hydrogen and produce no pollution at all have also been developed (see Figure 22.14). "
water shortages will become a problem in some areas because,(A) Drought will become more common and more severe (B) Groundwater resources will be reduced (C) Reduced snowpack and earlier spring will reduce snowmelt as a summer water source (D) All of these,C,"Water scarcity can have dire consequences for the people, the economy, and the environment. Without adequate water, crops and livestock dwindle and people go hungry. Industry, construction, and economic development is halted, causing a nation to sink further into poverty. The risk of regional conflicts over scarce water resources rises. People die from diseases, thirst, or even in war over scarce resources. Californias population is growing by hundreds of thousands of people a year, but much of the state receives as much annual rainfall as Morocco. With fish populations crashing, global warming, and the demands of the countrys largest agricultural industry, the pressures on our water supply are increasing. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
even an increase of global temperature of 1oc would make a difference to earths environment.,(A) True (B) False,A,"Computer models are used to predict the effects of greenhouse gas increases on climate for the planet as a whole and also for specific regions. If nothing is done to control greenhouse gas emissions and they continue to increase at current rates, the surface temperature of the Earth can be expected to increase between 0.5o C and 2.0o C (0.9o F and 3.6o F) by 2050 and between 2o and 4.5o C (3.5o and 8o F) by 2100, with CO2 levels over 800 parts per million (ppm). Global CO2 emissions are rising rapidly. The industrial revolution began about 1850 and industrialization has been ac- celerating. On the other hand, if severe limits on CO2 emissions begin soon, temperatures could rise less than 1.1o C (2o F) by 2100. Click image to the left or use the URL below. URL:  Whatever the temperature increase, it will not be uniform around the globe. A rise of 2.8o C (5o F) would result in 0.6o to 1.2o C (1o to 2o F) at the Equator, but up to 6.7o C (12o F) at the poles. So far, global warming has affected the North Pole more than the South Pole, but temperatures are still increasing at Antarctica (Figure 1.2). "
global warming has affected the south pole more than the north pole.,(A) True (B) False,B,"Ozone loss also occurs over the North Polar Region, but it is not enough for scientists to call it a hole. Why do you think there is less ozone loss over the North Pole area? The region of low ozone levels is small because the atmosphere is not as cold and PSCs do not form as readily. Still, springtime ozone levels are relatively low. This low moves south over some of the worlds most populated areas in Europe, North America, and Asia. At 40o N, the latitude of New York City, UV-B has increased about 4% per decade since 1978. At 55o N, the approximate latitude of Moscow and Copenhagen, the increase has been 6.8% per decade since 1978. Click image to the left or use the URL below. URL: "
predictions for what will happen in the future with our climate,(A) Are well known and very accurate (B) Are not well known (C) but the trends are clear (D) c Are really unknown (E) no more than a guess (F) d Will never be known,B,"Computer models are used to predict the effects of greenhouse gas increases on climate for the planet as a whole and also for specific regions. If nothing is done to control greenhouse gas emissions and they continue to increase at current rates, the surface temperature of the Earth can be expected to increase between 0.5o C and 2.0o C (0.9o F and 3.6o F) by 2050 and between 2o and 4.5o C (3.5o and 8o F) by 2100, with CO2 levels over 800 parts per million (ppm). Global CO2 emissions are rising rapidly. The industrial revolution began about 1850 and industrialization has been ac- celerating. On the other hand, if severe limits on CO2 emissions begin soon, temperatures could rise less than 1.1o C (2o F) by 2100. Click image to the left or use the URL below. URL:  Whatever the temperature increase, it will not be uniform around the globe. A rise of 2.8o C (5o F) would result in 0.6o to 1.2o C (1o to 2o F) at the Equator, but up to 6.7o C (12o F) at the poles. So far, global warming has affected the North Pole more than the South Pole, but temperatures are still increasing at Antarctica (Figure 1.2). "
temperatures are rising globally. how much they rise in the future depends on our actions in the next decades.,(A) True (B) False,A,"With more greenhouse gases trapping heat, average annual global temperatures are rising. This is known as global warming. "
the entire increase in global temperatures seen in the past two decades was caused by,(A) An increase in the sun’s irradiance (B) An increase in El Nino and La Nino cycles (C) Natural changes in greenhouse gas levels (D) None of these,D,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
"oceans are becoming more acidic, which means that",(A) Organisms with carbonate shells will have a more difficult time growing (B) Marine organisms will move toward the poles (C) Temperatures will increase (D) All of these,A,"Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic. Burning fossil fuels has led to an increase in carbon dioxide in the atmosphere. This carbon dioxide is then absorbed by the oceans, which lowers the pH of the water. Ocean acidification can kill corals and shellfish. It may also cause marine organisms to reproduce less, which could harm other organisms in the food chain. As a result, there also may be fewer marine organisms for humans to consume. "
a decrease in snow pack can cause a shortage of the summer water supply in many regions.,(A) True (B) False,A,"Global warming will change patterns of rainfall and water distribution. As the Earth warms, regions that currently receive an adequate supply of rain may shift. Regions that rely on snowmelt may find that there is less snow and the melt comes earlier and faster in the spring, causing the water to run off and not be available through the dry summers. A change in temperature and precipitation would completely change the types of plants and animals that can live successfully in that region. "
which of the following is true of mercury pollution?,(A) Mercury is a pollutant that easily travels far from where it was released (B) Mercury pollution only comes from manmade sources (C) Mercury pollution primarily affects the reproductive system of mammals (D) Mercury is found in gasoline and paint,A,"Mercury is released into the atmosphere when coal is burned (Figure 1.1). But breathing the mercury is not harmful. In the atmosphere, the mercury forms small droplets that are deposited in water or sediments. "
which of these happened because of the chemicals buried in love canal?,(A) Steel drums rusted releasing hazardous waste into the soil (B) Children were developing burns and getting sick (C) Toxic swamps were created by heavy rains (D) All of the above,D,"The Love Canal disaster actually began back in the mid 1900s. The disaster continues even today. Starting in the early 1940s, a big chemical company put thousands of barrels of chemical waste into an old canal. Over the next 10 years, the company dumped almost 22,000 tons of chemicals into the ground! In the early 1950s, the company covered over the barrels in the canal with soil. Then they sold the land to the city for just a dollar. The city needed the land in order to build an elementary school. The company warned the city that toxic waste was buried there. But they thought the waste was safe. The school and hundreds of homes were also built over the old canal. As it turned out, the cheap price was no bargain. Chemicals started leaking from the barrels. Chemicals seeped into basements. Chemicals bubbled up to the surface of the ground. In some places, plants wouldnt even grow on the soil. People noticed bad smells. Many got sick, especially the children. Residents wanted to know if the old chemicals were the cause. But they had a hard time getting officials to listen. So they demonstrated and demanded answers. Finally, the soil was tested and was found to be contaminated with harmful chemicals. For example, it contained a lot of lead and mercury. Both can cause permanent damage to the human nervous system. The school was closed. More than 200 homes were evacuated. Much of the Love Canal neighborhood was bulldozed away. The area had a massive clean-up effort. The cleanup cost millions of dollars. More than three decades later, much of Love Canal is still too contaminated to be safe for people. "
the superfund act of 1980 requires,(A) The federal government to clean up all toxic waste sites (B) Land that is damaged to be blocked off from the public (C) Just the Love Canal site to be cleaned up (D) Companies to clean up toxic waste sites they are responsible for,D,"Love Canal opened peoples eyes to toxic waste burial. They realized there must be other Love Canals all over the country. Thousands of contaminated sites were found. The Superfund Act was passed in 1980. The law required that money be set aside for cleanup of toxic waste sites, like the Elizabeth Copper Mine in Vermont (see the far-right image in Figure 19.9). The law also required safer disposal of hazardous waste in the future. "
"at love canal, barrels of toxic chemicals were",(A) Disposed of properly (B) Surrounded by impermeable materials and buried (C) Buried and covered with soil (D) Left out in the elements,C,"The story of Love Canal, New York, begins in the 1950s, when a local chemical company placed hazardous wastes in 55-gallon steel drums and buried them. Love Canal was an abandoned waterway near Niagara Falls and was thought to be a safe site for hazardous waste disposal because the ground was fairly impermeable (Figure 1.1). After burial, the company covered the containers with soil and sold the land to the local school system for $1. The company warned the school district that the site had been used for toxic waste disposal. Steel drums were used to contain 21,000 tons of hazardous chemicals at Love Canal. Soon a school, a playground, and 100 homes were built on the site. The impermeable ground was breached when sewer systems were dug into the rock layer. Over time, the steel drums rusted and the chemicals were released into the ground. In the 1960s people began to notice bad odors. Children developed burns after playing in the soil, and they were often sick. In 1977 a swamp created by heavy rains was found to contain 82 toxic chemicals, including 11 suspected cancer-causing chemicals. A Love Canal resident, Lois Gibbs, organized a group of citizens called the Love Canal Homeowners Association to try to find out what was causing the problems (See opening image). When they discovered that toxic chemicals were buried beneath their homes and school, they demanded that the government take action to clean up the area and remove the chemicals. "
"at love canal, people were told of the toxic chemicals buried beneath their homes and school when the community was built.",(A) True (B) False,B,"The story of Love Canal, New York, begins in the 1950s, when a local chemical company placed hazardous wastes in 55-gallon steel drums and buried them. Love Canal was an abandoned waterway near Niagara Falls and was thought to be a safe site for hazardous waste disposal because the ground was fairly impermeable (Figure 1.1). After burial, the company covered the containers with soil and sold the land to the local school system for $1. The company warned the school district that the site had been used for toxic waste disposal. Steel drums were used to contain 21,000 tons of hazardous chemicals at Love Canal. Soon a school, a playground, and 100 homes were built on the site. The impermeable ground was breached when sewer systems were dug into the rock layer. Over time, the steel drums rusted and the chemicals were released into the ground. In the 1960s people began to notice bad odors. Children developed burns after playing in the soil, and they were often sick. In 1977 a swamp created by heavy rains was found to contain 82 toxic chemicals, including 11 suspected cancer-causing chemicals. A Love Canal resident, Lois Gibbs, organized a group of citizens called the Love Canal Homeowners Association to try to find out what was causing the problems (See opening image). When they discovered that toxic chemicals were buried beneath their homes and school, they demanded that the government take action to clean up the area and remove the chemicals. "
lead poisoning was a problem in the 1970s and 1980s but that has been cleaned up.,(A) True (B) False,B,"Lead and mercury are two chemicals that are especially toxic to humans. Lead was once a common ingredient in gasoline and paint, but it was shown to damage human brains and nervous systems. Since young children are growing rapidly, lead is especially harmful in children under the age of six (Figure 1.2). In the 1970s and 1980s, the United States government passed laws completely banning lead in gasoline and paint. Homes built before the 1970s may contain lead paint. Paint so old is likely to be peeling and poses a great threat to human health. About 200 children die every year from lead poisoning. (a) Leaded gasoline. (b) Leaded paint. Mercury is a pollutant that can easily spread around the world. Sources of mercury include volcanic eruptions, coal burning, and wastes such as batteries, electronic switches, and electronic appliances such as television sets. Like lead, mercury damages the brain and impairs nervous system function. More about the hazards of mercury pollution can be found later in this concept. "
"groundwater in woburn, massachusetts contained this chemical, which was correlated with increased illnesses, such as leukemia, in children.",(A) Methane (B) TCE (C) Carbon Monoxide (D) DDT,B,"Sometimes the chemicals are not so easily seen as they were at Love Canal. But the impacts can be seen statistically. For example, contaminated drinking water may cause an increase in some types of cancer in a community. Why is one person with cancer not enough to suspect contamination by toxic waste? One is not a statistically valid number. A certain number of people get cancer all the time. To identify contamination, a number of cancers above the normal rate, called a cancer cluster, must be discovered. A case that was made into a book and movie called A Civil Action involved the community of Woburn, Massachusetts. Groundwater contamination was initially suspected because of an increase in childhood leukemia and other illnesses. As a result of concern by parents, the well water was analyzed and shown to have high levels of TCE (trichloroethylene). "
how do cancer cases cause scientists to suspect contamination as the cause?,(A) Every case of cancer is likely due to some type of hazardous waste (B) Childhood cancers nearly always indicate hazardous waste contamination (C) A cluster of cancer cases above the normal number causes suspicions (D) Cancers are almost never caused by hazardous waste contamination,C,"Sometimes the chemicals are not so easily seen as they were at Love Canal. But the impacts can be seen statistically. For example, contaminated drinking water may cause an increase in some types of cancer in a community. Why is one person with cancer not enough to suspect contamination by toxic waste? One is not a statistically valid number. A certain number of people get cancer all the time. To identify contamination, a number of cancers above the normal rate, called a cancer cluster, must be discovered. A case that was made into a book and movie called A Civil Action involved the community of Woburn, Massachusetts. Groundwater contamination was initially suspected because of an increase in childhood leukemia and other illnesses. As a result of concern by parents, the well water was analyzed and shown to have high levels of TCE (trichloroethylene). "
which age group is the most susceptible to health problems from toxic metals?,(A) Children because they are growing rapidly (B) Adults because their bodies are bigger (C) Older people because they are weaker (D) All age groups are equally susceptible,A,"Lead and mercury are two chemicals that are especially toxic to humans. Lead was once a common ingredient in gasoline and paint, but it was shown to damage human brains and nervous systems. Since young children are growing rapidly, lead is especially harmful in children under the age of six (Figure 1.2). In the 1970s and 1980s, the United States government passed laws completely banning lead in gasoline and paint. Homes built before the 1970s may contain lead paint. Paint so old is likely to be peeling and poses a great threat to human health. About 200 children die every year from lead poisoning. (a) Leaded gasoline. (b) Leaded paint. Mercury is a pollutant that can easily spread around the world. Sources of mercury include volcanic eruptions, coal burning, and wastes such as batteries, electronic switches, and electronic appliances such as television sets. Like lead, mercury damages the brain and impairs nervous system function. More about the hazards of mercury pollution can be found later in this concept. "
the atmosphere is composed of 78% __________ and 21% __________.,(A) Carbon dioxide; oxygen (B) Oxygen; nitrogen (C) Nitrogen; carbon dioxide (D) Nitrogen; oxygen,D,"Nitrogen and oxygen together make up 99% of the planets atmosphere. Nitrogen makes up the bulk of the atmosphere, but is not involved in geological or biological processes in its gaseous form. Nitrogen fixing is described in the chapter Life on Earth. Oxygen is extremely important because it is needed by animals for respiration. The rest of the gases are minor components but sometimes are very important (Figure 1.1). Nitrogen and oxygen make up 99% of the atmosphere; carbon dioxide is a very important minor component. "
photosynthesis helps plants create __________ from __________.,(A) Food energy; solar energy (B) Solar energy; food energy (C) Sugar; carbon dioxide gas (D) Carbon dioxide gas; sugar,A,"In plants, most chloroplasts are found in the leaves. Therefore, all the raw materials needed for photosynthesis must be present in the leaves. These materials include light, water, and carbon dioxide. The shape of the leaves gives them a lot of surface area to absorb light for photosynthesis. Roots take up water from the soil. Stems carry the water from the roots to the leaves. Carbon dioxide enters the leaves through tiny openings called stomata. (The oxygen released during photosynthesis also exits the leaves through the stomata.) "
the atmosphere is a reservoir for water.,(A) True (B) False,A,"As part of the hydrologic cycle, water spends a lot of time in the atmosphere, mostly as water vapor. The atmosphere is an important reservoir for water. Chlorophyll indicates the presence of photosynthesizing plants as does the veg- etation index. "
"in space, no one can hear you scream, because there is not medium for the sound waves to travel through",(A) True (B) False,A,"The atmosphere is made of gases that take up space and transmit energy. Sound waves are among the types of energy that travel though the atmosphere. Without an atmosphere, we could not hear a single sound. Earth would be as silent as outer space (explosions in movies about space should be silent). Of course, no insect, bird, or airplane would be able to fly, because there would be no atmosphere to hold it up. Click image to the left or use the URL below. URL: "
the ozone molecule is made of,(A) Two water molecules (B) Three oxygen atoms (C) One carbon dioxide molecule with a water molecule (D) Two oxygen atoms with one water molecule,B,"Ozone is a molecule composed of three oxygen atoms, (O3 ). Ozone in the upper atmosphere absorbs high-energy ultraviolet (UV) radiation coming from the Sun. This protects living things on Earths surface from the Suns most harmful rays. Without ozone for protection, only the simplest life forms would be able to live on Earth. The highest concentration of ozone is in the ozone layer in the lower stratosphere. "
the red chlorophyll hotspots on the chlorophyll map are directly related to the excess nutrients in those areas.,(A) True (B) False,A,"In a marine ecosystem, algae are the producers. Through photosynthesis, they provide glucose for the ecosystem. So, can too much algae be a bad thing? Eutrophication is an over-enrichment of chemical nutrients in a body of water. Usually these nutrients are the nitrogen and phosphorous found in fertilizers. Run-off from lawns or farms can wash fertilizers into rivers or coastal waters. Plants are not the only things that grow more quickly with added fertilizers. Algae like the excess nutrients in fertilizers too. When there are high levels of nutrients in the water, algae populations will grow large very quickly. This leads to overgrowths of algae called algal blooms. However, these algae do not live very long. They die and begin to decompose. This process uses oxygen, removing the oxygen from the water. Without oxygen, fish and shellfish cannot live, and this results in the death of these organisms ( Figure 1.1). Certain types of algal blooms can also create toxins. These toxins can enter shellfish. If humans eat these shellfish, then they can get very sick. These toxins cause neurological problems in humans. "
"without oxygen in the atmosphere, there would be",(A) No plants (B) No animals (C) No plants or animals (D) No difference in life forms,B,"Without the atmosphere, there would be no clouds or rain. In fact, there would be no weather at all. Most weather occurs because the atmosphere heats up more in some places than others. "
what is the relationship between photosynthesis in plants and the respiration of animals?,(A) Plants use CO2 and produce O2; animals use O2 and produce CO2 (B) Plants use O2 and produce CO2; animals use CO2 and produce O2 (C) Plants use nitrogen and produce water vapor; animals use water vapor and produce nitrogen (D) Plants use water vapor and produce nitrogen; animals use nitrogen and produce water vapor,A,"Plants and animals engage in the reverse of photosynthesis, which is respiration. In respiration, animals use oxygen to convert the organic carbon in sugar into food energy they can use. Plants also go through respiration and consume some of the sugars they produce. The chemical reaction for respiration is: C6 H12 O6 + 6 O2  6 CO2 + 6 H2 O + useable energy Photosynthesis and respiration are a gas exchange process. In photosynthesis, CO2 is converted to O2 ; in respiration, O2 is converted to CO2 . Remember that plants do not create energy. They change the energy from sunlight into chemical energy that plants and animals can use as food (Figure 1.1). "
what would happen if there were no greenhouse gases in the atmosphere?,(A) Temperatures would be frigid all the time and the ice ages would return (B) Temperatures would be extremely hot all the time (C) Temperatures would be frigid at night and scorching in the day (D) Ultraviolet radiation from the sun would fry all live on the surface,C,"Along with the oceans, the atmosphere keeps Earths temperatures within an acceptable range. Without an atmo- sphere, Earths temperatures would be frigid at night and scorching during the day. If the 12-year-old in the scenario above asked why, she would find out. Greenhouse gases trap heat in the atmosphere. Important greenhouse gases include carbon dioxide, methane, water vapor, and ozone. "
how does the atmosphere protect us from the sun?,(A) Ozone in the lower atmosphere absorbs all wavelengths of electromagnetic radiation from the sun (B) Greenhouse gases in the atmosphere absorb solar radiation to block out the harmful rays (C) Greenhouse gases in the upper atmosphere absorb heat from the planet and block out harmful radiation (D) Ozone in the upper atmosphere absorbs the highest energy ultraviolet radiation coming,D,The atmosphere protects living things from the Suns most harmful rays. Gases reflect or absorb the strongest rays of sunlight. Figure 15.1 models this role of the atmosphere. 
how are oceans important?,(A) They keep Earth’s temperature the same (B) They are a small part of the water cycle (C) They provide lots of habitats so that they have a lot of different species of organisms (D) All of the above,C,"Oceans cover more than 70 percent of Earths surface and hold 97 percent of its surface water. Its no surprise that the oceans have a big influence on the planet. The oceans affect the atmosphere, climate, and living things. "
biodiversity is the total mass of living organisms in a region.,(A) True (B) False,B,"Biodiversity refers to the variety of life and its processes. It includes the variation in living organisms, the genetic differences among them, and the range of communities and ecosystems in which they live. Scientists have identified about 1.9 million species alive today, but they are discovering new species all the time. How many species actually exist in the world? No one knows for sure because only a small percentage of them have already been discovered. Estimates range from 5 to 30 million total species currently in existence. Many of them live on coral reefs and in tropical rainforests (see Figure 25.14). These two ecosystems have some of the greatest biodiversity on the planet. "
which of the following is not true?,(A) Oceans give Earth a more moderate climate (B) Without oceans there would be less evaporation and so less precipitation on Earth (C) Without oceans (D) Earth would have much less biodiversity (E) d Earth is an enormous reservoir for water,B,"If the hypothesis above about falling objects really were false, it is likely that this would be discovered sooner or later after enough objects had been dropped. It takes just one exception to disprove a hypothesis. But what if the hypothesis really is true? Can this be demonstrated as well? No; it would require testing all possible combinations of objects to show that they always reach the ground at the same time. This is impossible. New objects are being made all the time that would have to be tested. Its always possible an exception would be found in the future to disprove the hypothesis. Although you cant prove conclusively that a hypothesis is true, the more evidence you gather in support of it, the more likely it is to be true. "
which of the following is true?,(A) Water changes temperature more quickly than land (B) Water changes temperature more quickly than the atmosphere (C) Water changes temperature more slowly than land (D) None of these,C,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
temperature range is smaller on land near a large water body than on land far from a large water body.,(A) True (B) False,A,"When a place is near an ocean, the water can have a big effect on the climate. "
oceans moderate earths temperature by,(A) Absorbing heat near the equator and moving it nearer to the poles (B) Absorbing heat near the Tropic of Cancer in the summer and moving it near the Tropic of Capricorn in the winter (C) Absorbing heat near the Tropic of Capricorn in the summer and moving it near the Tropic of Capricorn in the winter (D) None of these,A,"The oceans, along with the atmosphere, keep temperatures fairly constant worldwide. While some places on Earth get as cold as -70o C and others as hot as 55o C, the range is only 125o C. On Mercury temperatures go from -180o C to 430o C, a range of 610o C. The oceans, along with the atmosphere, distribute heat around the planet. The oceans absorb heat near the Equator and then move that solar energy to more polar regions. The oceans also moderate climate within a region. At the same latitude, the temperature range is smaller in lands nearer the oceans than away from the oceans. Summer temperatures are not as hot, and winter temperatures are not as cold, because water takes a long time to heat up or cool down. "
the oceans important to the water cycle because most evaporation comes from and precipitation falls on the oceans.,(A) True (B) False,A,"The oceans are an essential part of Earths water cycle. Since they cover so much of the planet, most evaporation comes from oceans and most precipitation falls on oceans. "
how are oceans important to climate?,(A) They distribute heat around the planet (B) They moderate climate within a region (C) They lessen the temperature range of nearby lands (D) All of the above,D,"When a place is near an ocean, the water can have a big effect on the climate. "
marine life,(A) Is not as abundant or diverse as terrestrial life (B) Supplies us with food and oxygen (C) Is less well adapted to its habitats than terrestrial life (D) All of these,B,"The oceans are home to an enormous amount of life. That is, they have tremendous biodiversity (Figure 1.1). Tiny ocean plants, called phytoplankton, create the base of a food web that supports all sorts of life forms. Marine life makes up the majority of all biomass on Earth. (Biomass is the total mass of living organisms in a given area.) These organisms supply us with food and even the oxygen created by marine plants. Polar bears are well adapted to frigid Arc- tic waters. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
the range of temperatures on earth is much less than the range in temperatures on mercury.,(A) True (B) False,A,"The oceans, along with the atmosphere, keep temperatures fairly constant worldwide. While some places on Earth get as cold as -70o C and others as hot as 55o C, the range is only 125o C. On Mercury temperatures go from -180o C to 430o C, a range of 610o C. The oceans, along with the atmosphere, distribute heat around the planet. The oceans absorb heat near the Equator and then move that solar energy to more polar regions. The oceans also moderate climate within a region. At the same latitude, the temperature range is smaller in lands nearer the oceans than away from the oceans. Summer temperatures are not as hot, and winter temperatures are not as cold, because water takes a long time to heat up or cool down. "
igneous rocks weather faster than most other rocks because they formed in conditions that are the most different from surface conditions.,(A) True (B) False,B,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
limestone weathers relatively rapidly because,(A) It forms at greater depth and is less stable than rocks that form near the surface (B) It dissolves in weak acids (C) It has lots of fractures (D) which expose it to weathering (E) d None of the above,B,"Each type of rock weathers in its own way. Certain types of rock are very resistant to weathering. Igneous rocks tend to weather slowly because they are hard. Water cannot easily penetrate them. Granite is a very stable igneous rock. Other types of rock are easily weathered because they dissolve easily in weak acids. Limestone is a sedimentary rock that dissolves easily. When softer rocks wear away, the more resistant rocks form ridges or hills. Devils Tower in Wyoming shows how different types of rock weather at different rates (Figure 9.5). The softer materials of the surrounding rocks were worn away. The resistant center of the volcano remains behind. Minerals also weather differently. Some minerals completely dissolve in water. As less resistant minerals dissolve away, a rocks surface becomes pitted and rough. When a less resistant mineral dissolves, more resistant mineral grains are released from the rock. "
a rock will weather more quickly in which climate,(A) Hot and dry (B) Cold and wet (C) Cold and dry (D) Hot and wet,D,"Scientists know that climate is the most important factor determining soil type because, given enough time, different rock types in a given climate will produce a similar soil (Figure 1.1). Even the same rock type in different climates will not produce the same type of soil. This is true because most rocks on Earth are made of the same eight elements and when the rock breaks down to become soil, those elements dominate. The same factors that lead to increased weathering also lead to greater soil formation. More rain equals more chemical reactions to weather minerals and rocks. Those reactions are most efficient in the top layers of the soil, where the water is fresh and has not yet reacted with other materials. Increased rainfall increases the amount of rock that is dissolved as well as the amount of material that is carried away by moving water. As materials are carried away, new surfaces are exposed, which also increases the rate of weathering. Climate is the most important factor in determining the type of soil that will form in a particular area. Increased temperature increases the rate of chemical reactions, which also increases soil formation. In warmer regions, plants and bacteria grow faster, which helps to weather material and produce soils. In tropical regions, where temperature and precipitation are consistently high, thick soils form. Arid regions have thin soils. Soil type also influences the type of vegetation that can grow in the region. We can identify climate types by the types of plants that grow there. "
water helps weathering because,(A) It increases the temperature (B) It increases the number of chemical reactions (C) It increases the amount of oxygen that’s available for oxidation (D) It increases the difference in weathering between different types of minerals,B,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
how is aluminum ore made?,(A) Intense chemical weathering removes soluble minerals and leaves aluminum oxide (B) Exposed aluminum is oxidized in air (C) Chemical reactions on tree roots concentrate aluminum oxide (D) Aluminum oxide precipitates out of saline water and onto a lake bed,A,"The ores journey to becoming a useable material is only just beginning when the ore leaves the mine (Figure separated out of the ore. A few methods for extracting ore are: heap leaching: the addition of chemicals, such as cyanide or acid, to remove ore. flotation: the addition of a compound that attaches to the valuable mineral and floats. smelting: roasting rock, causing it to segregate into layers so the mineral can be extracted. To extract the metal from the ore, the rock is melted at a temperature greater than 900o C, which requires a lot of energy. Extracting metal from rock is so energy-intensive that if you recycle just 40 aluminum cans, you will save the energy equivalent of one gallon of gasoline. "
chemical reactions proceed more rapidly at higher temperatures.,(A) True (B) False,A,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. They are more likely to bump into one another and to collide with greater force. For example, when you fry an egg, turning up the heat causes the egg to cook faster. The same principle explains why storing food in a cold refrigerator reduces the rate at which food spoils (see Figure 8.16). Both food frying and food spoiling are chemical reactions that happen faster at higher temperatures. "
climate is determined by,(A) Temperature (B) Precipitation (C) Temperature & precipitation (D) None of these,A,Climate is the average weather of a place over many years. It includes average temperatures. It also includes average precipitation. The timing of precipitation is part of climate as well. What determines the climate of a place? Latitude is the main factor. A nearby ocean or mountain range can also play a role. 
"when a less resistant mineral dissolves, more resistant mineral grains are released from rock.",(A) True (B) False,A,"Each type of rock weathers in its own way. Certain types of rock are very resistant to weathering. Igneous rocks tend to weather slowly because they are hard. Water cannot easily penetrate them. Granite is a very stable igneous rock. Other types of rock are easily weathered because they dissolve easily in weak acids. Limestone is a sedimentary rock that dissolves easily. When softer rocks wear away, the more resistant rocks form ridges or hills. Devils Tower in Wyoming shows how different types of rock weather at different rates (Figure 9.5). The softer materials of the surrounding rocks were worn away. The resistant center of the volcano remains behind. Minerals also weather differently. Some minerals completely dissolve in water. As less resistant minerals dissolve away, a rocks surface becomes pitted and rough. When a less resistant mineral dissolves, more resistant mineral grains are released from the rock. "
precipitation increases both mechanical and chemical weathering.,(A) True (B) False,A,"Mechanical weathering increases the rate of chemical weathering. As rock breaks into smaller pieces, the surface area of the pieces increases Figure 1.5. With more surfaces exposed, there are more surfaces on which chemical weathering can occur. Mechanical weathering may increase the rate of chemical weathering. Click image to the left or use the URL below. URL: "
quartz sand is very common on beaches. why might that be?,(A) Quartz is light so it floats downstream to the beaches more easily (B) The other minerals are so heavy they fall to the bottom of a stream and don’t make it to the beach (C) Quartz is resistant to weathering so it is left after the other minerals are gone (D) Quartz is easily weathered so it is weathered out and transported to the beach,C,"In relatively quiet areas along a shore, waves may deposit sand. Sand forms a beach, like the one in Figure 10.13. Many beaches include bits of rock and shell. You can see a close-up photo of beach deposits in Figure 10.14. "
which of these is not an inner planet?,(A) Venus (B) Mars (C) Jupiter (D) Earth,C,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
"together, all of the planets equal the mass of the sun.",(A) True (B) False,B,"Since the time of Copernicus, Kepler, and Galileo, we have learned a lot more about our solar system. Astronomers have discovered two more planets (Uranus and Neptune), five dwarf planets (Ceres, Pluto, Makemake, Haumea, and Eris), more than 150 moons, and many, many asteroids and other small objects. Although the Sun is just an average star compared to other stars, it is by far the largest object in the solar system. The Sun is more than 500 times the mass of everything else in the solar system combined! Table 1.1 gives data on the sizes of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter Object Mass (Relative to Earth) Mars Jupiter Saturn Uranus Neptune 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass 17.2 Earths mass Diameter of Planet (Relative to Earth) 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter 3.81 Earths diameter "
why is earths natural satellite unique among the inner planets?,(A) No other inner planet has a satellite (B) No other inner planet has a large (C) planet-like satellite (D) c No other inner planet has a captured asteroid for a satellite (E) d None of the above,B,"One of the most unique features of planet Earth is its large Moon. Unlike the only other natural satellites orbiting an inner planet, those of Mars, the Moon is not a captured asteroid. Understanding the Moons birth and early history reveals a great deal about Earths early days. "
the inner planets are made of,(A) An igneous rock mantle with an iron core (B) Iron and nickel metal in the mantle and core (C) A metal core with a metamorphic and igneous rock mantle (D) A metamorphic rock mantle and an igneous rock core,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
all of the inner planets were geologically active at some time in their history.,(A) True (B) False,A,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
the outer planets are called the _________ and the inner planets are called the __________.,(A) Rocky planets; Gas giants (B) Gassy planets; rocky planets (C) Gas giants; terrestrial planets (D) Large planets; small planets,C,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
gas giants are primarily made up of _________________.,(A) Helium and lithium (B) Oxygen and carbon dioxide (C) Carbon dioxide and methane (D) Hydrogen and helium,D,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
saturn is unique in the solar system because it is the only planet with rings.,(A) True (B) False,B,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
"compared to the outer planets, the inner planets have",(A) Slower orbits (B) Slower spin (C) Few or no satellites (D) All of the above,D,"The inner planets, or terrestrial planets, are the four planets closest to the Sun: Mercury, Venus, Earth, and Mars. Figure 1.1 shows the relative sizes of these four inner planets. Unlike the outer planets, which have many satellites, Mercury and Venus do not have moons, Earth has one, and Mars has two. Of course, the inner planets have shorter orbits around the Sun, and they all spin more slowly. Geologically, the inner planets are all made of cooled igneous rock with iron cores, and all have been geologically active, at least early in their history. None of the inner planets has rings. Click image to the left or use the URL below. URL:  This composite shows the relative sizes of the four inner planets. From left to right, they are Mercury, Venus, Earth, and Mars. "
planetary rings are made up of,(A) Metal (B) Dust and small rocks (C) Gases and ices (D) All of the above,B,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
what two elements make up the sun?,(A) Oxygen and Carbon (B) Zeon and Neon (C) Boron and Iron (D) Helium and Hydrogen,D,"The Sun is made almost entirely of the elements hydrogen and helium. The Sun has no solid material. Most atoms in the Sun exist as plasma. Plasma is superheated gas with an electrical charge. Because the Sun is made of gases, it does not have a defined outer boundary. Like Earth, the Sun has an internal structure. The inner three layers make up what we would actually call the Sun. "
"the sun is made of ______, a fourth state of matter made of__________.",(A) Plasma; superheated gas with a negative electrical charge (B) Plasma; superheated gas with a positive electrical charge (C) Liquoid; superheated liquid with a neutral electrical charge (D) Liquioid; superheated liquid with a negative electrical charge,B,"The Sun is made almost entirely of the elements hydrogen and helium. The Sun has no solid material. Most atoms in the Sun exist as plasma. Plasma is superheated gas with an electrical charge. Because the Sun is made of gases, it does not have a defined outer boundary. Like Earth, the Sun has an internal structure. The inner three layers make up what we would actually call the Sun. "
the sun is a ball of material with no layers and no outer boundary.,(A) True (B) False,B,"The Sun is made almost entirely of the elements hydrogen and helium. The Sun has no solid material. Most atoms in the Sun exist as plasma. Plasma is superheated gas with an electrical charge. Because the Sun is made of gases, it does not have a defined outer boundary. Like Earth, the Sun has an internal structure. The inner three layers make up what we would actually call the Sun. "
the suns energy,(A) Is generated by the fusion of helium into hydrogen (B) Moves outward away from the center (C) Is released by nuclear fission (D) All of the above,B,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
the photosphere is,(A) The region of the Sun that emits sunlight (B) Hotter than the rest of the Sun (C) The solid surface of the Sun (D) All of these,A,"The photosphere is the visible surface of the Sun (Figure 24.17). Its the part that we see shining. Surprisingly, the photosphere is also one of the coolest layers of the Sun. It is only about 6000 degrees C. "
"when the moon blocks out the sun in a solar eclipse, we can still see the corona.",(A) True (B) False,A,"When a new moon passes directly between the Earth and the Sun, it causes a solar eclipse (Figure 24.20). The Moon casts a shadow on the Earth and blocks our view of the Sun. This happens only all three are lined up and in the same plane. This plane is called the ecliptic. The ecliptic is the plane of Earths orbit around the Sun. The Moons shadow has two distinct parts. The umbra is the inner, cone-shaped part of the shadow. It is the part in which all of the light has been blocked. The penumbra is the outer part of Moons shadow. It is where the light is only partially blocked. When the Moons shadow completely blocks the Sun, it is a total solar eclipse (Figure 24.21). If only part of the Sun is out of view, it is a partial solar eclipse. Solar eclipses are rare events. They usually only last a few minutes. That is because the Moons shadow only covers a very small area on Earth and Earth is turning very rapidly. Solar eclipses are amazing to experience. It appears like night only strange. Birds may sing as they do at dusk. Stars become visible in the sky and it gets colder outside. Unlike at night, the Sun is out. So during a solar eclipse, its easy to see the Suns corona and solar prominences. This NASA page will inform you on when solar eclipses are expected: http://eclipse.gsfc.nasa.gov/solar.html "
a particle of light is called a ______________.,(A) Proton (B) Electron (C) Photon (D) Futon,C,The Sun gives off energy in tiny packets called photons. Photons travel in waves. Figure 15.7 models a wave of light. Notice the wavelength in the figure. Waves with shorter wavelengths have more energy. 
which section of the sun helps create the solar flares and sunspots?,(A) Convection zone (B) Radiative zone (C) Chromosphere (D) Corona layer,A,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
the temperature of the sun is highest in the central plasma core.,(A) True (B) False,A,"The core is the Suns innermost layer. The core is plasma. It has a temperature of around 15 million degrees Celsius (C). Nuclear fusion reactions create the immense temperature. In these reactions, hydrogen atoms fuse to form helium. This releases vast amounts of energy. The energy moves towards the outer layers of the Sun. Energy from the Suns core powers most of the solar system. "
"in the radiative zone,",(A) Convection currents rise and fall rapidly (B) Nuclear fusion takes place (C) but at a lower rate than in the core (D) c Photons move very slowly as they are absorbed and released by other particles (E) d All of these,C,"The radiative zone is the next layer out. It has a temperature of about 4 million degrees C. Energy from the core travels through the radiative zone. The rate the energy travels is extremely slow. Light particles, called photons, can only travel a few millimeters before they hit another particle. The particles are absorbed and then released again. It may take 50 million years for a photon to travel all the way through the radiative zone. "
the amount of water that is available to enter groundwater in a region is this.,(A) Capillary Action (B) Discharge (C) Well water (D) Recharge,D,"The amount of water that is available to enter groundwater in a region, called recharge, is influenced by the local climate, the slope of the land, the type of rock found at the surface, the vegetation cover, land use in the area, and water retention, which is the amount of water that remains in the ground. More water goes into the ground where there is a lot of rain, flat land, porous rock, exposed soil, and where water is not already filling the soil and rock. "
water moves through pores from wet soil to dry areas by,(A) Recharge (B) Solvency (C) Capillary action (D) Aquifericity,C,"Some water soaks into the ground. It travels down through tiny holes in soil. It seeps through cracks in rock. The water moves slowly, pulled deeper and deeper by gravity. Underground water can also erode and deposit material. "
unconfined aquifers are open to the surface.,(A) True (B) False,A,"Most land areas have aquifers beneath them. Many aquifers are used by people for freshwater. The closer to the surface an aquifer is, the easier it is to get the water. However, an aquifer close to the surface is also more likely to become polluted. Pollutants can seep down through porous rock in recharge water. An aquifer that is used by people may not be recharged as quickly as its water is removed. The water table may lower and the aquifer may even run dry. If this happens, the ground above the aquifer may sink. This is likely to damage any homes or other structures built above the aquifer. "
which is an example of a discharge area?,(A) Water table (B) Stream (C) Well (D) None of these,B,"Another example of static discharge, but on a much larger scale, is lightning. You can see how it occurs in the following diagram (Figure 1.1). During a rainstorm, clouds develop regions of positive and negative charge due to the movement of air molecules, water drops, and ice particles. The negative charges are concentrated at the base of the clouds, and the positive charges are concentrated at the top. The negative charges repel electrons on the ground beneath them, so the ground below the clouds becomes positively charged. At first, the atmosphere prevents electrons from flowing away from areas of negative charge and toward areas of positive charge. As more charges build up, however, the air between the oppositely charged areas also becomes charged. When this happens, static electricity is discharged as bolts of lightning. "
"if a shallow well runs dry, a deeper well will likely tap another aquifer.",(A) True (B) False,A,"Some aquifers are overused; people pump out more water than is replaced. As the water is pumped out, the water table slowly falls, requiring wells to be dug deeper, which takes more money and energy. Wells may go completely dry if they are not deep enough to reach into the lowered water table. Other problems may stem from groundwater overuse. Subsidence and saltwater intrusion are two of them. "
when did most fossil water enter its aquifer?,(A) Around the end of the ice ages (B) During the ice ages (C) During the time of the dinosaurs (D) At the time massive amounts of water were first formed on Earth,A,"The residence time of water in a groundwater aquifer can be from minutes to thousands of years. Groundwater is often called fossil water because it has remained in the ground for so long, often since the end of the ice ages. A diagram of groundwater flow through aquifers showing residence times. Deeper aquifers typically contain older ""fossil water."" Click image to the left or use the URL below. URL: "
are there aquifers in desert areas?,(A) No (B) it is too dry (C) b Yes (D) they are found near the surface just as in wet areas (E) c Yes (F) but only deep ones (G) d No (H) aquifers are in mountainous areas,C,"Groundwater resides in aquifers, porous rock and sediment with water in between. Water is attracted to the soil particles, and capillary action, which describes how water moves through porous media, moves water from wet soil to dry areas. Aquifers are found at different depths. Some are just below the surface and some are found much deeper below the land surface. A region may have more than one aquifer beneath it and even most deserts are above aquifers. The source region for an aquifer beneath a desert is likely to be far away, perhaps in a mountainous area. "
most groundwater has been in an aquifer for millennia.,(A) True (B) False,B,"The residence time of water in a groundwater aquifer can be from minutes to thousands of years. Groundwater is often called fossil water because it has remained in the ground for so long, often since the end of the ice ages. A diagram of groundwater flow through aquifers showing residence times. Deeper aquifers typically contain older ""fossil water."" Click image to the left or use the URL below. URL: "
access to groundwater can only be gotten from wells.,(A) True (B) False,B,"Most groundwater does not flow out of an aquifer as a spring or geyser. So to use the water thats stored in an aquifer people must go after it. How? They dig a well. A well is a hole that is dug or drilled through the ground down to an aquifer. This is illustrated in Figure 13.18. People have depended on water from wells for thousands of years. To bring water to the surface takes energy because the force of gravity must be overcome. Today, many wells use electricity to pump water to the surface. However, in some places, water is still brought to the surface the old-fashioned way  with human labor. The well pictured in Figure 13.19 is an example of this type of well. A hand-cranked pulley is used to lift the bucket of water to the surface. "
igneous extrusive rocks exhibit,(A) No visible crystals (B) Mostly microscopic crystals with perhaps a few larger crystals (C) Mostly larger crystals with a few microscopic crystals filling in the spaces between them (D) Larger crystals (E) all visible with the naked eye,B,Extrusive igneous rocks cool at the surface. Volcanoes are one type of feature that forms from extrusive rocks. Several other interesting landforms are also extrusive features. Intrusive igneous rocks cool below the surface. These rocks do not always remain hidden. Rocks that formed in the crust are exposed when the rock and sediment that covers them is eroded away. 
to create a large mountain range of igneous intrusive rocks requires,(A) Magma to flow over the surface and to pile up in mountains (B) Magma to cool beneath ocean water and then the ocean to move elsewhere (C) Magma to cool deep in the crust and then for the plutons to be uplifted (D) None of these,C,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
igneous intrusive rock has visible crystals because it cools and solidifies slowly.,(A) True (B) False,A,"Igneous rocks form when magma cools and forms crystals. These rocks can form at Earths surface or deep underground. Figure 4.7 shows a landscape in Californias Sierra Nevada that consists entirely of granite. Intrusive igneous rocks cool and form into crystals beneath the surface. Deep in the Earth, magma cools slowly. Slow cooling gives large crystals a chance to form. Intrusive igneous rocks have relatively large crystals that are easy to see. Granite is the most common intrusive igneous rock. Figure 4.8 shows four types of intrusive rocks. Extrusive igneous rocks form above the surface. The lava cools quickly as it pours out onto the surface (Figure "
a pluton is a large igneous rock that cooled inside the crust.,(A) True (B) False,A,"Igneous rocks are called intrusive when they cool and solidify beneath the surface. Intrusive rocks form plutons and so are also called plutonic. A pluton is an igneous intrusive rock body that has cooled in the crust. When magma cools within the Earth, the cooling proceeds slowly. Slow cooling allows time for large crystals to form, so intrusive igneous rocks have visible crystals. Granite is the most common intrusive igneous rock (see Figure 1.1 for an example). Igneous rocks make up most of the rocks on Earth. Most igneous rocks are buried below the surface and covered with sedimentary rock, or are buried beneath the ocean water. In some places, geological processes have brought Granite is made of four minerals, all visible to the naked eye: feldspar (white), quartz (translucent), hornblende (black), and bi- otite (black, platy). igneous rocks to the surface. Figure 1.2 shows a landscape in Californias Sierra Nevada Mountains made of granite that has been raised to create mountains. Californias Sierra Nevada Mountains are intrusive igneous rock exposed at Earths surface. "
a rock texture that indicates the presence of gas bubbles.,(A) Porphyritic (B) Vesicular (C) Intrusive (D) Extrusive,B,The rate at which magma cools determines whether an igneous rock is intrusive or extrusive. The cooling rate is reflected in the rocks texture. 
a rock texture in which visible crystals are found in a matrix of tiny crystals.,(A) Porphyritic (B) Vesicular (C) Intrusive (D) Extrusive,A,"Magma heats nearby underground water, which reacts with the rocks around it to pick up dissolved particles. As the water flows through open spaces in the rock and cools, it deposits solid minerals. The mineral deposits that form when a mineral fills cracks in rocks are called veins (Figure 1.4). Quartz veins formed in this rock. When minerals are deposited in open spaces, large crystals form (Figure 1.5). Amethyst formed when large crystals grew in open spaces inside the rock. These special rocks are called geodes. "
"which of these igneous rocks cooled so quickly that crystals did not form, creating a natural glassy look?",(A) Pumice (B) Basalt (C) Granite (D) Obsidian,B,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
which of these igneous rock types have a vesicular texture?,(A) Pumice (B) Basalt (C) Granite (D) Obsidian,A,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
if a rock is cooling in a magma chamber for a while and then suddenly erupts it will have a porphyritic texture.,(A) True (B) False,A,The rate at which magma cools determines whether an igneous rock is intrusive or extrusive. The cooling rate is reflected in the rocks texture. 
lava that cools extremely rapidly may have a crystalline texture.,(A) True (B) False,B,"Igneous rocks are called extrusive when they cool and solidify above the surface. These rocks usually form from a volcano, so they are also called volcanic rocks (Figure 1.3). Extrusive igneous rocks cool much more rapidly than intrusive rocks. There is little time for crystals to form, so extrusive igneous rocks have tiny crystals (Figure 1.4). Some volcanic rocks have a different texture. The rock has large crystals set within a matrix of tiny crystals. In this Extrusive igneous rocks form after lava cools above the surface. Cooled lava forms basalt with no visible crystals. Why are there no visible crys- tals? Cooling rate and gas content create other textures (see Figure 1.5 for examples of different textures). Lavas that cool extremely rapidly may have a glassy texture. Those with many holes from gas bubbles have a vesicular texture. Different cooling rate and gas content resulted in these different textures. Click image to the left or use the URL below. URL: "
which is the nearest of the gas giant planets to the sun?,(A) Pluto (B) Uranus (C) Jupiter (D) None of the above,C,"The four planets farthest from the Sun are the outer planets. Figure 1.2 shows the relative sizes of the outer planets and the Sun. These planets are much larger than the inner planets and are made primarily of gases and liquids, so they are also called gas giants. The gas giants are made up primarily of hydrogen and helium, the same elements that make up most of the Sun. Astronomers think that hydrogen and helium gases comprised much of the solar system when it first formed. Since the inner planets didnt have enough mass to hold on to these light gases, their hydrogen and helium floated away into space. The Sun and the massive outer planets had enough gravity to keep hydrogen and helium from drifting away. All of the outer planets have numerous moons. They all also have planetary rings, composed of dust and other small particles that encircle the planet in a thin plane. Click image to the left or use the URL below. URL:  This image shows the four outer planets and the Sun, with sizes to scale. From left to right, the outer planets are Jupiter, Saturn, Uranus, and Neptune. "
jupiter,(A) Has highly pressurized ices at its center (B) Is made mostly of hydrogen and some helium (C) Has a solid surface that a spacecraft could land on (D) All of the above,B,"Jupiter, shown in Figure 25.19, is the largest planet in our solar system. Jupiter is named for the king of the gods in Roman mythology. Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earths volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from the Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
jupiter is so large that it makes its own light.,(A) True (B) False,B,"Jupiter is enormous, the largest object in the solar system besides the Sun. Although Jupiter is over 1,300 times Earths volume, it has only 318 times the mass of Earth. Like the other gas giants, it is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. Jupiter is extremely bright in the night sky; only the Moon and Venus are brighter (Figure 1.1). This brightness is all the more impressive because Jupiter is quite far from the Earth  5.20 AUs away. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
jupiter is 5.2 times as from the sun as the earth is.,(A) True (B) False,A,"Jupiter is enormous, the largest object in the solar system besides the Sun. Although Jupiter is over 1,300 times Earths volume, it has only 318 times the mass of Earth. Like the other gas giants, it is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. Jupiter is extremely bright in the night sky; only the Moon and Venus are brighter (Figure 1.1). This brightness is all the more impressive because Jupiter is quite far from the Earth  5.20 AUs away. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
jupiter has,(A) A faint ring system (B) At least 63 moons (C) Some evidence for a small rocky core (D) All of the above,D,"Jupiter, shown in Figure 25.19, is the largest planet in our solar system. Jupiter is named for the king of the gods in Roman mythology. Jupiter is truly a giant! The planet has 318 times the mass of Earth, and over 1,300 times Earths volume. So Jupiter is much less dense than Earth. Because Jupiter is so large, it reflects a lot of sunlight. When it is visible, it is the brightest object in the night sky besides the Moon and Venus. Jupiter is quite far from the Earth. The planet is more than five times as far from Earth as the Sun. It takes Jupiter about 12 Earth years to orbit once around the Sun. "
the galilean moons,(A) Are Io (B) Europa (C) Ganymede and Callisto (D) b Were discovered by Galileo through his telescope in 1610 (E) c Are larger than the dwarf planet Pluto (F) d All of the above,D,"Jupiter has lots of moons. As of 2011, we have discovered over 60 natural satellites of Jupiter. Four are big enough and bright enough to be seen from Earth using a pair of binoculars. These four moons were first discovered by Galileo in 1610. They are called the Galilean moons. Figure 25.21 shows the four Galilean moons and their sizes relative to Jupiters Great Red Spot. These moons are named Io, Europa, Ganymede, and Callisto. The Galilean moons are larger than even the biggest dwarf planets, Pluto and Eris. Ganymede is the biggest moon in the solar system. It is even larger than the planet Mercury! Scientists think that Europa is a good place to look for extraterrestrial life. Europa is the smallest of the Galilean moons. The moons surface is a smooth layer of ice. Scientists think that the ice may sit on top of an ocean of liquid water. How could Europa have liquid water when it is so far from the Sun? Europa is heated by Jupiter. Jupiters tidal forces are so great that they stretch and squash its moon. This could produce enough heat for there to be liquid water. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecrafts, Voyager 1 and Voyager 2, visited Jupiter and its moons. Photos from the Voyager missions "
what is the great red spot found on jupiter?,(A) A mark left over from reactions of hydrogen (B) helium (C) and ammonia (D) b Iron-oxide dust blowing in a giant storm (E) c A band of red rocks (F) d A giant storm in the atmosphere,D,"The upper layer of Jupiters atmosphere contains clouds of ammonia (NH3 ) in bands of different colors. These bands rotate around the planet, but also swirl around in turbulent storms. The Great Red Spot (Figure 1.3) is an enormous, oval-shaped storm found south of Jupiters equator. This storm is more than three times as wide as the entire Earth. Clouds in the storm rotate in a counterclockwise direction, making one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years, since astronomers could first see the storm through telescopes. Do you think the Great Red Spot is a permanent feature on Jupiter? How could you know? This image of Jupiters Great Red Spot (upper right of image) was taken by the Voyager 1 spacecraft. The white storm just below the Great Red Spot is about the same diameter as Earth. "
how do scientists know the minimum length of time the great red spot has been on jupiter?,(A) It was first seen through the naked eye and recorded more than 400 years ago (B) They have done calculations and they know a feature of that type would last at least 750 years (C) It has been at least 300 years since it was seen through a telescope (D) None of these,C,"The upper layer of Jupiters atmosphere contains clouds of ammonia (NH3 ) in bands of different colors. These bands rotate around the planet, but also swirl around in turbulent storms. The Great Red Spot (Figure 1.3) is an enormous, oval-shaped storm found south of Jupiters equator. This storm is more than three times as wide as the entire Earth. Clouds in the storm rotate in a counterclockwise direction, making one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years, since astronomers could first see the storm through telescopes. Do you think the Great Red Spot is a permanent feature on Jupiter? How could you know? This image of Jupiters Great Red Spot (upper right of image) was taken by the Voyager 1 spacecraft. The white storm just below the Great Red Spot is about the same diameter as Earth. "
"jupiters moon, europa, is a place to search for extraterrestrial life because it",(A) May have a liquid water ocean beneath its solid ice surface (B) Has heat from the Sun as an energy source (C) Emits organic molecules into its atmosphere (D) All of these,A,"Jupiter has a very large number of moons  63 have been discovered so far. Four are big enough and bright enough to be seen from Earth, using no more than a pair of binoculars. These moons  Io, Europa, Ganymede, and Callisto were first discovered by Galileo in 1610, so they are sometimes referred to as the Galilean moons (Figure 1.4). The Galilean moons are larger than the dwarf planets Pluto, Ceres, and Eris. Ganymede is not only the biggest moon in the solar system; it is even larger than the planet Mercury! Scientists are particularly interested in Europa because it may be a place to find extraterrestrial life. What features might make a satellite so far from the Sun a candidate for life? Although the surface of Europa is a smooth layer of ice, there is evidence that there is an ocean of liquid water underneath (Figure 1.5). Europa also has a continual source of energy  it is heated as it is stretched and squashed by tidal forces from Jupiter. Numerous missions have been planned to explore Europa, including plans to drill through the ice and send a probe into the ocean. However, no such mission has yet been attempted. In 1979, two spacecraft  Voyager 1 and Voyager 2  visited Jupiter and its moons. Photos from the Voyager missions showed that Jupiter has a ring system. This ring system is very faint, so it is difficult to observe from Earth. This composite image shows the four Galilean moons and their sizes relative to the Great Red Spot. From top to bottom, the moons are Io, Europa, Ganymede, and Callisto. Jupiters Great Red Spot is in the background. Sizes are to scale. Click image to the left or use the URL below. URL: "
jupiters atmosphere contains,(A) Thick carbon dioxide (B) which causes runaway greenhouse effect (C) b Ammonia clouds in different colored bands (D) c Methane gas from decaying life (E) d All of these,B,"Astronauts trying to land a spaceship on the surface of Jupiter would find that there is no solid surface at all! Jupiter is made mostly of hydrogen, with some helium, and small amounts of other elements (Figure 1.2). Jupiters atmosphere is composed of hydrogen and helium. Deeper within the planet, pressure compresses the gases into a liquid. Some evidence suggests that Jupiter may have a small rocky core of heavier elements at its center. This image of Jupiter was taken by Voy- ager 2 in 1979. The colors were later enhanced to bring out more details. "
long ridges of material dumped at the furthest point the glacier reached.,(A) End moraines (B) Lateral moraines (C) Ground moraines (D) Terminal moraines,D,"Valley glaciers form several unique features through erosion. You can see some of them in Figure 10.28. As a valley glacier flows through a V-shaped river valley, it scrapes away the sides of the valley. It carves a U-shaped valley with nearly vertical walls. A line called the trimline shows the highest level the glacier reached. A cirque is a rounded hollow carved in the side of a mountain by a glacier. The highest cliff of a cirque is called the headwall. An arte is a jagged ridge that remains when cirques form on opposite sides of a mountain. A low spot in an arte is called a col. A horn is a sharp peak that is left behind when glacial cirques are on at least three sides of a mountain. "
"on a mountain, a glacier originates in a",(A) Horn (B) Arete (C) Cirque (D) Coll,C,"Nearly all glacial ice, 99%, is contained in ice sheets in the polar regions, particularly Antarctica and Greenland. Glaciers often form in the mountains because higher altitudes are colder and more likely to have snow that falls and collects. Every continent, except Australia, hosts at least some glaciers in the high mountains. "
unsorted deposits of rock are called a glacial ________________.,(A) Erratics (B) Till (C) Drumlin (D) Valley,B,Melting glaciers deposit all the big and small bits of rocky material they are carrying in a pile. These unsorted deposits of rock are called glacial till. Glacial till is found in different types of deposits. Linear rock deposits are called moraines. Geologists study moraines to figure out how far glaciers extended and how long it took them to melt away. Moraines are named by their location relative to the glacier: Lateral moraines form at the edges of the glacier as material drops onto the glacier from erosion of the valley walls. Medial moraines form where the lateral moraines of two tributary glaciers join together in the middle of a larger glacier (Figure 1.7). Ground moraines forms from sediments that were beneath the glacier and left behind after the glacier melts. Ground moraine sediments contribute to the fertile transported soils in many regions. Terminal moraines are long ridges of till left at the furthest point the glacier reached. End moraines are deposited where the glacier stopped for a long enough period to create a rocky ridge as it retreated. Long Island in New York is formed by two end moraines. 
"a large rock that was dumped by a glacier, sometimes far from where it originated is a",(A) Glacial striations (B) Glacial erratic (C) Glacial till (D) Glacial moraine,B,Rocks carried by a glacier are eventually dropped. These glacial erratics are noticeable because they are a different rock type from the surrounding bedrock. 
glaciers can carry rocks of any size.,(A) True (B) False,A,"As glaciers flow, mechanical weathering loosens rock on the valley walls, which falls as debris on the glacier. Glaciers can carry rock of any size, from giant boulders to silt (Figure 1.6). These rocks can be carried for many kilometers for many years. "
"varves display an annual cycle of dark, fine clays deposited in winter and lighter sands deposited in spring.",(A) True (B) False,A,"Lake sediments, especially in lakes that are located at the end of glaciers, also have an annual pattern. In the summer, the glacier melts rapidly, producing a thick deposit of sediment. These alternate with thin, clay-rich layers deposited in the winter. The resulting layers, called varves, give scientists clues about past climate conditions (Figure 1.3). A warm summer might result in a very thick sediment layer while a cooler summer might yield a thinner layer. "
the water falls in yosemite are created by water falling down from a,(A) Cirque (B) Tributary valley (C) V-shaped valley (D) Hanging valley,D,"Mountain streams may erode waterfalls. As shown in Figure 10.5, a waterfall forms where a stream flows from an area of harder to softer rock. The water erodes the softer rock faster than the harder rock. This causes the stream bed to drop down, like a step, creating a waterfall. As erosion continues, the waterfall gradually moves upstream. "
a ridge of bedrock carved by a glacier is a(n) __________; a ridge of till deposited by a stream beneath a glacier is a(n) __________.,(A) Arête; esker (B) Esker; arête (C) Horn; lateral moraine (D) Lateral moraine; horn,A,"Glaciers deposit their sediment when they melt. They drop and leave behind whatever was once frozen in their ice. Its usually a mixture of particles and rocks of all sizes, called glacial till. Water from the melting ice may form lakes or other water features. Figure 10.29 shows some of the landforms glaciers deposit when they melt. Moraine is sediment deposited by a glacier. A ground moraine is a thick layer of sediments left behind by a retreating glacier. An end moraine is a low ridge of sediments deposited at the end of the glacier. It marks the greatest distance the glacier advanced. A drumlin is a long, low hill of sediments deposited by a glacier. Drumlins often occur in groups called drumlin fields. The narrow end of each drumlin points in the direction the glacier was moving when it dropped the sediments. An esker is a winding ridge of sand deposited by a stream of meltwater. Such streams flow underneath a retreating glacier. A kettle lake occurs where a chunk of ice was left behind in the sediments of a retreating glacier. When the ice melted, it left a depression. The meltwater filled it to form a lake. "
how do glaciers erode underlying rocks?,(A) Glacial striations (B) Saltation (C) Abrasion and plucking (D) Ice wedging,C,"Glaciers erode the underlying rock by abrasion and plucking. Glacial meltwater seeps into cracks of the underlying rock. When the water freezes, it pushes pieces of rock outward. The rock is then plucked out and carried away by the flowing ice of the moving glacier (Figure 1.1). With the weight of the ice over them, these rocks can scratch deeply into the underlying bedrock, making long, parallel grooves in the bedrock, called glacial striations. Mountain glaciers leave behind unique erosional features. When a glacier cuts through a V-shaped river valley, the glacier plucks rocks from the sides and bottom. This widens the valley and steepens the walls, making a U-shaped valley (Figure 1.2). Smaller tributary glaciers, like tributary streams, flow into the main glacier in their own shallower U-shaped valleys. A hanging valley forms where the main glacier cuts off a tributary glacier and creates a cliff. Streams plunge over the cliff to create waterfalls (Figure 1.3). Up high on a mountain, where a glacier originates, rocks are pulled away from valley walls. Some of the resulting erosional features are shown in Figure 1.4 and Figure 1.5. Glacial striations point the direction a glacier has gone. A U-shaped valley in Glacier National Park. Click image to the left or use the URL below. URL:  Yosemite Valley is known for waterfalls that plunge from hanging valleys. (a) A bowl-shaped cirque in Glacier Na- tional Park was carved by glaciers. (b) A high altitude lake, called a tarn, forms from meltwater trapped in the cirque. (c) Several cirques from glaciers flowing in different directions from a mountain peak, leave behind a sharp sided horn, like the Matterhorn in Switzerland. (d) When glaciers move down opposite sides of a mountain, a sharp edged ridge, called an arte, forms between them. Snowmelt and melting glaciers combine to create a fast moving stream at Glacier National Park. "
much of the work of erosion at a shore is done by,(A) Longshore currents (B) Waves (C) Rip currents (D) Rivers,B,"Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. "
shorelines are often straight because,(A) Waves come in parallel to the shoreline (B) Longshore currents erode in a fairly straight line (C) Waves come in perpendicular to the shoreline (D) Wave refraction concentrates or disperses energy,D,Most waves strike the shore at an angle. This causes longshore drift. Longshore drift moves sediment along the shore. Sediment is moved up the beach by an incoming wave. The wave approaches at an angle to the shore. Water then moves straight offshore. The sediment moves straight down the beach with it. The sediment is again picked up by a wave that is coming in at an angle. This motion is show in Figure 10.15 and at the link below. 
the erosion of a sea arch can form this.,(A) Cliff (B) Sea stack (C) Beach (D) Sea wall,B,Erosion by waves can create unique landforms (Figure 10.12). Wave-cut cliffs form when waves erode a rocky shoreline. They create a vertical wall of exposed rock layers. Sea arches form when waves erode both sides of a cliff. They create a hole in the cliff. Sea stacks form when waves erode the top of a sea arch. This leaves behind pillars of rock. 
"a long, narrow pile of rocks built perpendicular to the shoreline to keep sand t the beach.",(A) Groin (B) Seawall (C) Sea stack (D) Breakwater,A,"Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. "
"a long, narrow bar of sand that form parallel to the shore by wave transport of sand is a",(A) Beach (B) Groin (C) Barrier Island (D) Spit,C,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
a shorelines first line of defense against hurricanes is,(A) Beaches (B) Lagoons (C) Spits (D) Barrier Islands,D,"Barrier islands provide natural protection to shorelines. Storm waves strike the barrier island before they reach the shore. People also build artificial barriers, called breakwaters. Breakwaters also protect the shoreline from incoming waves. You can see an example of a breakwater in Figure 10.18. It runs parallel to the coast like a barrier island. "
"a length of sand that connects to land and extends into the water, with a hook at the end is a",(A) Spit (B) Tombolo (C) Barrier island (D) Groin,B,Deposits from longshore drift may form a spit. A spit is a ridge of sand that extends away from the shore. The end of the spit may hook around toward the quieter waters close to shore. You can see a spit in Figure 10.16. Waves may also deposit sediments to form sandbars and barrier islands. You can see examples of these landforms in Figure 10.17. 
the problem with groins is,(A) They starve the beach down-current of them of sand (B) They starve the beach up-current of them of sand (C) They are easily taken out by a rogue wave coming in perpendicular to the shore (D) They are often knocked down by long-shore currents,A,"Longshore drift can erode the sediment from a beach. To keep this from happening, people may build a series of groins. A groin is wall of rocks or concrete that juts out into the ocean perpendicular to the shore. It stops waves from moving right along the beach. This stops the sand on the upcurrent side and reduces beach erosion. You can see how groins work in Figure 10.19. "
"engineers can build structures that will protect our shorelines, come what may.",(A) True (B) False,B,"Shores are attractive places to live and vacation. But development at the shore is at risk of damage from waves. Wave erosion threatens many homes and beaches on the ocean. This is especially true during storms, when waves may be much larger than normal. "
"compared with the sand on a low energy beach, the sand on a high energy beach will be",(A) A mixture of minerals (B) rock fragments and shells (C) b Mostly shells (D) c Mostly hard minerals like quartz (E) d It’s impossible to say,C,"The girls in Figure 18.4 are having fun at the beach. Its a warm, sunny day, and the sand feels hot under their bare hands and feet. The water, in contrast, feels much cooler. Why does the sand get so hot while the water does not? The answer has to do with specific heat. Specific heat is the amount of energy (in joules) needed to raise the temperature of 1 gram of a substance by 1C. Specific heat is a property that is specific to a given type of matter. Table 18.1 lists the specific heat of four different substances. Metals such as iron have relatively low specific heat. It doesnt take much energy to raise their temperature. Thats why a metal spoon heats up quickly when placed in hot coffee. Sand also has a relatively low specific heat, whereas water has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land also affect climate. To learn how, watch the video at this URL:  MEDIA Click image to the left or use the URL below. URL:  In Table 18.1, how much greater is the specific heat of water than sand? Substances iron sand wood water Specific Heat (joules) 0.45 0.67 1.76 4.18 "
the creation of rock from sediments is called,(A) Solidification (B) Lithification (C) Cementation (D) Compaction,B,"Weathering wears rocks at the Earths surface down into smaller pieces. The small fragments are called sediments. Running water, ice, and gravity all transport these sediments from one place to another by erosion. During sedimen- tation, the sediments are laid down or deposited. In order to form a sedimentary rock, the accumulated sediment must become compacted and cemented together. "
when fluid deposit ions create a rock that binds loose sediment it is called,(A) Solidification (B) Lithification (C) Cementation (D) Compaction,C,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
when sediments are squeezed together by the weight of sediments and rocks on top of them it is called,(A) Solidification (B) Lithification (C) Cementation (D) Compaction,D,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
clastic rocks contain fragments of pre-existing rock.,(A) True (B) False,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
the order of how sedimentary rocks are made is,(A) Erosion (B) compaction (C) cementation (D) lithification (E) b Compaction (F) cementation (G) lithification (H) erosion (I) c Erosion (J) cementation (K) compaction (L) lithification (M) d Erosion (N) lithification (O) cementation (P) compaction,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
a mudstone that contains shell fragments is a bioclastic rock.,(A) True (B) False,A,The presence of marine organisms in a rock indicates that the region where the rock was deposited was once marine. Sometimes fossils of marine organisms are found on tall mountains indicating that rocks that formed on the seabed were uplifted. 
the grains of sand in a sandstone are,(A) The age the sands became a rock (B) The age of the rock that the grains weathered and eroded from (C) All the same age (D) None of these,B,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
lithification creates,(A) Clastic or bioclastic sedimentary rocks (B) Igneous rocks (C) Fossiliferous metamorphic rocks (D) Chemical sedimentary rocks,A,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
compaction is when cement from fluids bind sediments together.,(A) True (B) False,B,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
sandstone is a type of clastic rock.,(A) True (B) False,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
latitude,(A) Is a distance north or south of the Equator (B) Is a number between 0 and 100 degrees (C) Runs east and west of the International Date Line (D) Is divided into 90 degrees (E) 90 minutes and 90 seconds,A,"Latitude is the distance north or south of the equator. Its measured in degrees, from 0 to 90 . Several climate factors vary with latitude. "
latitude and longitude are used to describe a location,(A) Relative to the Equator (B) Above sea level (C) On Earth’s surface (D) Using a measurement divided into 90 degrees (E) 90 minutes and 90 seconds,C,"Most maps use a grid of lines to help you to find your location. This grid system is called a geographic coordinate system. Using this system you can define your location by two numbers, latitude and longitude. Both numbers are angles between your location, the center of Earth, and a reference line (Figure 2.20). "
the height above or below sea level.,(A) Longitude (B) Latitude (C) Elevation (D) Direction,C,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
a latitude of 44o2743 should be followed by an n or s.,(A) True (B) False,A,"A look on a reliable website shows us that Old Faithful Geyser is located at N44o 27 43. What does this mean? Latitude tells the distance north or south of the Equator. Latitude lines start at the Equator and circle around the planet. The North Pole is 90o N, with 90 degree lines in the Northern Hemisphere. Old Faithful is at 44 degrees, 27 minutes and 43 seconds north of the Equator. Thats just about exactly half way between the Equator and the North Pole! "
earths magnetic north pole and geographic north pole are located at the point where earths axis of rotation intersects the surface.,(A) True (B) False,B,"Although a compass always points north, it doesnt point to Earths geographic north pole, which is located at 90 north latitude (see Figure 24.11). Instead, it points to Earths magnetic north pole, which is located at about 80 north latitude. Earths magnetic south pole is also located several degrees of latitude away from the geographic south pole. A compass pointer has north and south poles, and its north pole points to Earths magnetic north pole. Why does this happen if opposite poles attract? Why doesnt the compass needle point south instead? The answer may surprise you. Earths magnetic north pole is actually the south pole of magnet Earth! Its called the magnetic north pole to avoid confusion. Because its close to the geographic north pole, it would be confusing to call it the magnetic south pole. "
a longitude of 44o2743 should be followed by an n or s.,(A) True (B) False,B,"If you know the latitude and longitude of a place, you can find it on a map. Simply place one finger on the latitude on the vertical axis of the map. Place your other finger on the longitude along the horizontal axis of the map. Move your fingers along the latitude and longitude lines until they meet. For example, say the location you want to find is at 30o N and 90o W. Place your right finger along 30o N at the right of the map. Place your left finger along the bottom at 90o W. Move your fingers along the lines until they meet. Your location should be near New Orleans, Louisiana, along the Gulf coast of the United States. What if you want to know the latitude and longitude of your location? If you know where you are on a map, point to the place with your fingers. Take one finger and move it along the latitude line to find your latitude. Then move another finger along the longitude line to find your and longitude. "
sea level is,(A) Nearly the same all around Earth (B) The average height of the ocean’s surface (C) The midpoint between high and low tide (D) All of the above,D,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
gps stands for,(A) Global Positioning Satellites (B) Geological Positioning System (C) Global Positioning System (D) Global Prime System,C,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
the highest point on earth is on,(A) Mount Rushmore (B) Mount Everest (C) Mount McKinley (D) Mount Kilimanjaro,B,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
a compass is a device with a floating needle that acts as a magnet point to magnetic north.,(A) True (B) False,A,"When an object is moving, it is not enough to describe its location. We also need to know direction. Direction is important for describing moving objects. For example, a wind blows a storm over your school. Where is that storm coming from? Where is it going? The most common way to describe direction is by using a compass. A compass is a device with a floating needle (Figure 2.1). The needle is a small magnet that aligns itself with the Earths magnetic field. The compass needle always points to magnetic north. If you have a compass and you find north, you can then know any other direction. See the directions, such as east, south, west, etc., on a compass rose. A compass needle lines up with Earths magnetic north pole. This is different from Earths geographic north pole, or true north. The geographic north pole is the top of the imaginary axis around which Earth rotates. The geographic north pole is much like the spindle of a spinning top. The location of the geographic north pole does not change. However, the magnetic north pole shifts in location over time. Depending on where you live, you can correct for the difference between the two poles when you use a map and a compass (Figure 2.2). Some maps have a double compass rose. This allows users to make the corrections between magnetic north and true north. An example is a nautical chart that boaters use to chart their positions at sea (Figure 2.3). "
which of these are greenhouse gases?,(A) Carbon dioxide (B) Methane (C) Water vapor (D) All of the above,D,"Remember that greenhouse gases trap heat in the atmosphere. Important natural greenhouse gases include carbon dioxide, methane, water vapor, and ozone. CFCs and some other man-made compounds are also greenhouse gases. "
carbon dioxide and methane levels in the atmosphere are correlated with temperature.,(A) True (B) False,A,Human activity has significantly raised the levels of many of greenhouse gases in the atmosphere. Methane levels are about 2 1/2 times higher as a result of human activity. Carbon dioxide has increased more than 35%. CFCs have only recently existed. What do you think happens as atmospheric greenhouse gas levels increase? More greenhouse gases trap more heat and warm the atmosphere. The increase or decrease of greenhouse gases in the atmosphere affect climate and weather the world over. Click image to the left or use the URL below. URL: 
which of these can cause climate to change?,(A) The amount of energy the Sun produces over the years (B) The tilt of the Earth’s axis (C) Asteroid impacts (D) All of the above,D,"Many processes can cause climate to change. These include changes: In the amount of energy the Sun produces over years. In the positions of the continents over millions of years. In the tilt of Earths axis and orbit over thousands of years. That are sudden and dramatic because of random catastrophic events, such as a large asteroid impact. In greenhouse gases in the atmosphere, caused naturally or by human activities. "
the climate cycle correlates with the sunspot cycle.,(A) True (B) False,B,"The amount of energy the Sun radiates is variable. Sunspots are magnetic storms on the Suns surface that increase and decrease over an 11-year cycle (Figure 1.1). When the number of sunspots is high, solar radiation is also relatively high. But the entire variation in solar radiation is tiny relative to the total amount of solar radiation that there is, and there is no known 11-year cycle in climate variability. The Little Ice Age corresponded to a time when there were no sunspots on the Sun. Sunspots on the face of the Sun. "
plate tectonics processes can alter climate such as,(A) When there is a supercontinent (B) heat is distributed more evenly around the planet (C) b When continents are near the poles (D) ice accumulates to maybe start an ice age (E) c When there is a supercontinent (F) there are more volcanic eruptions to block the sun (G) d All of these,B,"Plate tectonic movements can alter climate. Over millions of years as seas open and close, ocean currents may distribute heat differently. For example, when all the continents are joined into one supercontinent (such as Pangaea), nearly all locations experience a continental climate. When the continents separate, heat is more evenly distributed. Plate tectonic movements may help start an ice age. When continents are located near the poles, ice can accumulate, which may increase albedo and lower global temperature. Low enough temperatures may start a global ice age. Plate motions trigger volcanic eruptions, which release dust and CO2 into the atmosphere. Ordinary eruptions, even large ones, have only a short-term effect on weather (Figure 1.2). Massive eruptions of the fluid lavas that create lava plateaus release much more gas and dust, and can change climate for many years. This type of eruption is exceedingly rare; none has occurred since humans have lived on Earth. "
"when earths axis has less different in its tilt, climate is more moderate throughout the year.",(A) True (B) False,A,"The most extreme climate of recent Earth history was the Pleistocene. Scientists attribute a series of ice ages to variation in the Earths position relative to the Sun, known as Milankovitch cycles. The Earth goes through regular variations in its position relative to the Sun: 1. The shape of the Earths orbit changes slightly as it goes around the Sun. The orbit varies from more circular to more elliptical in a cycle lasting between 90,000 and 100,000 years. When the orbit is more elliptical, there is a greater difference in solar radiation between winter and summer. 2. The planet wobbles on its axis of rotation. At one extreme of this 27,000 year cycle, the Northern Hemisphere points toward the Sun when the Earth is closest to the Sun. Summers are much warmer and winters are much colder than now. At the opposite extreme, the Northern Hemisphere points toward the Sun when it is farthest from the Sun. An eruption like Sarychev Volcano (Kuril Islands, northeast of Japan) in 2009 would have very little impact on weather. This results in chilly summers and warmer winters. 3. The planets tilt on its axis varies between 22.1o and 24.5o . Seasons are caused by the tilt of Earths axis of rotation, which is at a 23.5o angle now. When the tilt angle is smaller, summers and winters differ less in temperature. This cycle lasts 41,000 years. When these three variations are charted out, a climate pattern of about 100,000 years emerges. Ice ages correspond closely with Milankovitch cycles. Since glaciers can form only over land, ice ages only occur when landmasses cover the polar regions. Therefore, Milankovitch cycles are also connected to plate tectonics. "
atmospheric carbon dioxide levels,(A) Are currently around 400 ppm (B) Have been higher than 400 ppm several times in the past 100 (C) 000 years (D) c Are the highest they have ever been in Earth history (E) d All of the above,A,"Remember that the amount of CO2 in the atmosphere is very low. This means that a small increase or decrease in the atmospheric CO2 can have a large effect. By measuring the composition of air bubbles trapped in glacial ice, scientists can learn the amount of atmospheric CO2 at times in the past. Of particular interest is the time just before the Industrial Revolution, when society began to use fossil fuels. That value is thought to be the natural content of CO2 for this time period; that number was 280 parts per million (ppm). By 1958, when scientists began to directly measure CO2 content from the atmosphere at Mauna Loa volcano in the Pacific Ocean, the amount was 316 ppm (Figure 1.2). In 2014, the atmospheric CO2 content had risen to around 400 ppm. The amount of CO2 in the atmosphere has been measured at Mauna Loa Obser- vatory since 1958. The blue line shows yearly averaged CO2 . The red line shows seasonal variations in CO2 . This is an increase in atmospheric CO2 of 40% since the before the Industrial Revolution. About 65% of that increase has occurred since the first CO2 measurements were made on Mauna Loa Volcano, Hawaii, in 1958. "
"ice ages happen predictably on a 100,000 year cycle that correlates with milankovitch cycles.",(A) True (B) False,B,"The most extreme climate of recent Earth history was the Pleistocene. Scientists attribute a series of ice ages to variation in the Earths position relative to the Sun, known as Milankovitch cycles. The Earth goes through regular variations in its position relative to the Sun: 1. The shape of the Earths orbit changes slightly as it goes around the Sun. The orbit varies from more circular to more elliptical in a cycle lasting between 90,000 and 100,000 years. When the orbit is more elliptical, there is a greater difference in solar radiation between winter and summer. 2. The planet wobbles on its axis of rotation. At one extreme of this 27,000 year cycle, the Northern Hemisphere points toward the Sun when the Earth is closest to the Sun. Summers are much warmer and winters are much colder than now. At the opposite extreme, the Northern Hemisphere points toward the Sun when it is farthest from the Sun. An eruption like Sarychev Volcano (Kuril Islands, northeast of Japan) in 2009 would have very little impact on weather. This results in chilly summers and warmer winters. 3. The planets tilt on its axis varies between 22.1o and 24.5o . Seasons are caused by the tilt of Earths axis of rotation, which is at a 23.5o angle now. When the tilt angle is smaller, summers and winters differ less in temperature. This cycle lasts 41,000 years. When these three variations are charted out, a climate pattern of about 100,000 years emerges. Ice ages correspond closely with Milankovitch cycles. Since glaciers can form only over land, ice ages only occur when landmasses cover the polar regions. Therefore, Milankovitch cycles are also connected to plate tectonics. "
what natural process removes carbon dioxide from the atmosphere?,(A) Volcanic eruptions (B) Decay or burning organic matter (C) Absorption by plant and animal tissue (D) All of the above,C,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
how do scientists determine the age of a seafloor basalt?,(A) They can get a radiometric age if they can collect a sample (B) They can use the time scale for magnetic reversals (C) They can look at fossils in the sediments on top of the basaltic rocks (D) All of these,D,"The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Scientists also discovered that the mid-ocean ridge crest is nearly sediment free. The crust is also very thin there. With distance from the ridge crest, the sediments and crust get thicker. This also supports the idea that the youngest rocks are on the ridge axis and that the rocks get older with distance away from the ridge (Figure 6.12). Something causes the seafloor to be created at the ridge crest. The seafloor is also destroyed in a relatively short time. "
what is true about the seafloor near mid-ocean ridge?,(A) Rocks are younger closer to the ridge (B) The crust is thicker near the ridge (C) The magnetic stripes are thinnest near the ridge and get thicker with distance away from the ridge (D) All of the above,A,"Plates move apart at mid-ocean ridges. Lava rises upward, erupts, and cools. Later, more lava erupts and pushes the original seafloor outward. This is seafloor spreading. Seafloor spreading forms new oceanic crust. The rising magma causes earthquakes. Most mid-ocean ridges are located deep below the sea. The island of Iceland sits right on the Mid-Atlantic ridge (Figure 6.17). "
submarines during wwii discovered the magnetic patterns on the seafloor.,(A) True (B) False,B,Warships also carried magnetometers. They were also used to search for submarines. The magnetometers also revealed a lot about the magnetic properties of the seafloor. 
"the magnetic stripes on either side of the mid-ocean ridge, the same distance out from the ridge, have opposite polarity.",(A) True (B) False,B,"Scientists were also surprised to discover a pattern of stripes of normal and reversed polarity. These stripes surround the mid-ocean ridges. There is one long stripe with normal magnetism at the top of the ridge. Next to that stripe are two long stripes with reversed magnetism. One is on either side of the normal stripe. Next come two normal stripes and then two reversed stripes, and so on across the ocean floor. The magnetic stripes end abruptly at the edges of continents. Sometimes the stripes end at a deep sea trench (Figure 6.11). "
"with increasing age, seafloor rocks",(A) Wear away to become thinner (B) Become hotter (C) Collect an increasing amount of sediment on top (D) All of these,C,"The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Scientists also discovered that the mid-ocean ridge crest is nearly sediment free. The crust is also very thin there. With distance from the ridge crest, the sediments and crust get thicker. This also supports the idea that the youngest rocks are on the ridge axis and that the rocks get older with distance away from the ridge (Figure 6.12). Something causes the seafloor to be created at the ridge crest. The seafloor is also destroyed in a relatively short time. "
the oldest seafloor is less than 180 million years old.,(A) True (B) False,A,"The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Scientists also discovered that the mid-ocean ridge crest is nearly sediment free. The crust is also very thin there. With distance from the ridge crest, the sediments and crust get thicker. This also supports the idea that the youngest rocks are on the ridge axis and that the rocks get older with distance away from the ridge (Figure 6.12). Something causes the seafloor to be created at the ridge crest. The seafloor is also destroyed in a relatively short time. "
what is not true about the magnetic stripes on the ocean floor?,(A) Stripes alternate (B) normal and reverse polarity (C) across the ocean floor (D) b Stripes indicate the age of the basaltic rock (E) c Stripes are evidence of apparent polar wander (F) d Stripes end abruptly at the edges of continents,C,"Scientists were also surprised to discover a pattern of stripes of normal and reversed polarity. These stripes surround the mid-ocean ridges. There is one long stripe with normal magnetism at the top of the ridge. Next to that stripe are two long stripes with reversed magnetism. One is on either side of the normal stripe. Next come two normal stripes and then two reversed stripes, and so on across the ocean floor. The magnetic stripes end abruptly at the edges of continents. Sometimes the stripes end at a deep sea trench (Figure 6.11). "
"navy ships use these to search for enemy submarines, but accidently discovered the magnetic polarity of the seafloor.",(A) Bar magnets (B) Magnetometers (C) Electromagnets (D) Echo sounders,B,Warships also carried magnetometers. They were also used to search for submarines. The magnetometers also revealed a lot about the magnetic properties of the seafloor. 
observations of the seafloor support the idea that new seafloor is created at mid- ocean ridges.,(A) True (B) False,A,"The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Scientists also discovered that the mid-ocean ridge crest is nearly sediment free. The crust is also very thin there. With distance from the ridge crest, the sediments and crust get thicker. This also supports the idea that the youngest rocks are on the ridge axis and that the rocks get older with distance away from the ridge (Figure 6.12). Something causes the seafloor to be created at the ridge crest. The seafloor is also destroyed in a relatively short time. "
"if it is true that new seafloor is created at mid-ocean ridges, then",(A) The planet must be getting bigger (B) Old seafloor must be destroyed somewhere (C) New seafloor must sink directly into the mantle (D) None of these,B,"The seafloor spreading hypothesis brought all of these observations together in the early 1960s. Hot mantle material rises up at mid-ocean ridges. The hot magma erupts as lava. The lava cools to form new seafloor. Later, more lava erupts at the ridge. The new lava pushes the seafloor that is at the ridge horizontally away from ridge axis. The seafloor moves! In some places, the oceanic crust comes up to a continent. The moving crust pushes that continent away from the ridge axis as well. If the moving oceanic crust reaches a deep sea trench, the crust sinks into the mantle. The creation and destruction of oceanic crust is the reason that continents move. Seafloor spreading is the mechanism that Wegener was looking for! "
crystals that point in the direction of the magnetic field.,(A) Magnetite (B) Granite (C) Peridotite (D) Hematite,A,"The magnetic field created by a current flowing through a wire actually surrounds the wire in concentric circles. This magnetic field is stronger if more current is flowing through the wire. The direction of the magnetic field also depends on the direction that the current is flowing through the wire. A simple rule, called the right hand rule, makes it easy to find the direction of the magnetic field if the direction of the current is known. The right hand rule is illustrated in Figure 25.3. When the thumb of the right hand is pointing in the same direction as the current, the fingers of the right hand curl around the wire in the direction of the magnetic field. You can see the right hand rule in action at this URL:  . "
a device capable of measuring the magnetic field intensity.,(A) Magnetoscope (B) Magnetite (C) Magnetometer (D) Magnemometer,C,"The device in the circuit in Figure 25.9 is an ammeter. It measures the current that flows through the wire. The faster the magnet or coil moves, the greater the amount of current that is produced. If more turns were added to the coil, this would increase the strength of the magnetic field as well. If the magnet were moved back and forth repeatedly, the current would keep changing direction. In other words, alternating current would be produced. This is illustrated in Figure 25.10. "
wegener died without knowing that continental drift was accepted.,(A) True (B) False,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
magnetite crystals in young volcanic rocks point to the geographic north pole.,(A) True (B) False,B,"Geologists noted important things about the magnetic polarity of different aged rocks on the same continent: Magnetite crystals in fresh volcanic rocks point to the current magnetic north pole (Figure 1.2) no matter what continent or where on the continent the rocks are located. Older rocks that are the same age and are located on the same continent point to the same location, but that location is not the current north magnetic pole. Older rocks that are of different ages do not point to the same locations or to the current magnetic north pole. In other words, although the magnetite crystals were pointing to the magnetic north pole, the location of the pole seemed to wander. Scientists were amazed to find that the north magnetic pole changed location over time (Figure Can you figure out the three possible explanations for this? They are: The location of the north magnetic north pole 80 million years before present (mybp), then 60, 40, 20, and now. 1. The continents remained fixed and the north magnetic pole moved. 2. The north magnetic pole stood still and the continents moved. 3. Both the continents and the north pole moved. "
magnetic crystals in older rocks of the same age on the same continent point to,(A) The current magnetic north pole (B) The same point (C) but not the current pole (D) c The magnetic south pole since the pole had flipped (E) d The geographic North Pole,B,"Geologists noted important things about the magnetic polarity of different aged rocks on the same continent: Magnetite crystals in fresh volcanic rocks point to the current magnetic north pole (Figure 1.2) no matter what continent or where on the continent the rocks are located. Older rocks that are the same age and are located on the same continent point to the same location, but that location is not the current north magnetic pole. Older rocks that are of different ages do not point to the same locations or to the current magnetic north pole. In other words, although the magnetite crystals were pointing to the magnetic north pole, the location of the pole seemed to wander. Scientists were amazed to find that the north magnetic pole changed location over time (Figure Can you figure out the three possible explanations for this? They are: The location of the north magnetic north pole 80 million years before present (mybp), then 60, 40, 20, and now. 1. The continents remained fixed and the north magnetic pole moved. 2. The north magnetic pole stood still and the continents moved. 3. Both the continents and the north pole moved. "
older rocks that are different ages on different continents indicate that,(A) The continents have moved (B) Everything is stationary (C) There are multiple north poles (D) The poles do wander,A,"The earliest felsic continental crust is now found in the ancient cores of continents, called the cratons. Rapid plate motions meant that cratons experienced many continental collisions. Little is known about the paleogeography, or the ancient geography, of the early planet, although smaller continents could have come together and broken up. Geologists can learn many things about the Pre-Archean by studying the rocks of the cratons. Cratons also contain felsic igneous rocks, which are remnants of the first continents. Cratonic rocks contain rounded sedimentary grains. Of what importance is this fact? Rounded grains indicate that the minerals eroded from an earlier rock type and that rivers or seas also existed. One common rock type in the cratons is greenstone, a metamorphosed volcanic rock (Figure 1.1). Since greenstones are found today in oceanic trenches, what does the presence of greenstones mean? These ancient greenstones indicate the presence of subduction zones. Ice age glaciers scraped the Canadian Shield down to the 4.28 billion year old greenstone in Northwestern Quebec. "
if the continents remained fixed while the magnetic pole moved there must have been two separate magnetic north poles.,(A) True (B) False,A,"How do you figure out which of those three possibilities is correct? You decide to look at magnetic rocks on different continents. Geologists noted that for rocks of the same age but on different continents, the little magnets pointed to different magnetic north poles. 400 million-year-old magnetite in Europe pointed to a different north magnetic pole than magnetite of the same age in North America. 250 million years ago, the north poles were also different for the two continents. Now look again at the three possible explanations. Only one can be correct. If the continents had remained fixed while the north magnetic pole moved, there must have been two separate north poles. Since there is only one north pole today, what is the best explanation? The only reasonable explanation is that the magnetic north pole has remained fixed but that the continents have moved. "
there is and was only one magnetic north pole.,(A) True (B) False,A,"How do you figure out which of those three possibilities is correct? You decide to look at magnetic rocks on different continents. Geologists noted that for rocks of the same age but on different continents, the little magnets pointed to different magnetic north poles. 400 million-year-old magnetite in Europe pointed to a different north magnetic pole than magnetite of the same age in North America. 250 million years ago, the north poles were also different for the two continents. Now look again at the three possible explanations. Only one can be correct. If the continents had remained fixed while the north magnetic pole moved, there must have been two separate north poles. Since there is only one north pole today, what is the best explanation? The only reasonable explanation is that the magnetic north pole has remained fixed but that the continents have moved. "
magnetite crystals pointing to the magnetic north pole show are evidence for continental drift if,(A) The pole is moving across the landscape (B) The pole is flipping with the magnetic south pole (C) The pole is stationary but the continent is moving (D) The pole is stationary and the continent is stationary,C,"How does this help you to provide evidence for continental drift? To test the idea that the pole remained fixed but the continents moved, geologists fitted the continents together as Wegener had done. It worked! There has only been one magnetic north pole and the continents have drifted (Figure 1.4). They named the phenomenon of the magnetic pole that seemed to move but actually did not apparent polar wander. On the left: The apparent north pole for Europe and North America if the continents were always in their current locations. The two paths merge into one if the continents are allowed to drift. This evidence for continental drift gave geologists renewed interest in understanding how continents could move about on the planets surface. "
what line of evidence made scientists realize that wegener was right about continental drift?,(A) The puzzle-like fit of the continents (B) The distribution of exact fossils on widely separated continents (C) The change in polarity of the magnetic field from normal to reverse (D) Apparent polar wander,D,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
topographic maps,(A) Use different colors to show different rock types (B) Use contour lines to show different elevations (C) Are also called geologic maps (D) All of the above,B,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
another name for contour maps is,(A) Resource map (B) Road map (C) Geologic map (D) Topographic map,D,"Topographic maps represent the locations of geographical features, such as hills and valleys. Topographic maps use contour lines to show different elevations. A contour line is a line of equal elevation. If you walk along a contour line you will not go uphill or downhill. Topographic maps are also called contour maps. The rules of topographic maps are: Each line connects all points of a specific elevation. Contour lines never cross since a single point can only have one elevation. Every fifth contour line is bolded and labeled. Adjacent contour lines are separated by a constant difference in elevation (such as 20 ft or 100 ft). The difference in elevation is the contour interval, which is indicated in the map legend. Scales indicate horizontal distance and are also found on the map legend. Old Faithful erupting, Yellowstone Na- tional Park. While the Figure 1.1 isnt exactly the same view as the map at the top of this concept, it is easy to see the main features. Hills, forests, development, and trees are all seen around Old Faithful. "
a bathymetric map represents the depth below sea level.,(A) True (B) False,A,"A bathymetric map is like a topographic map with the contour lines representing depth below sea level, rather than height above. Numbers are low near sea level and become higher with depth. Kilauea is the youngest volcano found above sea level in Hawaii. On the flank of Kilauea is an even younger volcano called Loihi. The bathymetric map pictured in the Figure 1.2 shows the form of Loihi. Loihi volcano growing on the flank of Kilauea volcano in Hawaii. Black lines in the inset show the land surface above sea level and blue lines show the topography below sea level. A geologic map of the region around Old Faithful, Yellowstone National Park. "
this type of map shows rock units and features like faults and folds.,(A) Topographic map (B) Bathymetric map (C) Geologic map (D) Contour map,C,A geologic map shows the geological features of a region (see Figure 1.3 for an example). Rock units are color- coded and identified in a key. Faults and folds are also shown on geologic maps. The geology is superimposed on a topographic map to give a more complete view of the geology of the region. Click image to the left or use the URL below. URL: 
"on a bathymetric map, numbers are negative because they represent depth below sea level.",(A) True (B) False,A,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
contour lines cross on very steep slopes.,(A) True (B) False,B,Contour lines connect all the points on the map that have the same elevation. Lets take a closer look at this (Figure Each contour line represents a specific elevation. The contour line connects all the points that are at the same elevation. Every fifth contour line is made bold. The bold contour lines have numbers to show elevation. Contour lines run next to each other and NEVER cross one another. If the lines crossed it would mean that one place had two different elevations. This cannot happen. 
"a geologic map of the grand canyon, with its layer cake geology, will look like this.",(A) Bands of colors from the top to the bottom of the canyon (B) Circles of different color from the top to the bottom of the canyon (C) Very steep contour lines with no other topographic features (D) All of the above,A,"A geologic map shows the different rocks that are exposed at the surface of a region. Rock units are shown in a color identified in a key. On the geologic map of the Grand Canyon, for example, different rock types are shown in different colors. Some people call the Grand Canyon layer cake geology because most of the rock units are in layers. Rock units show up on both sides of a stream valley. A geologic map looks very complicated in a region where rock layers have been folded, like the patterns in marble cake. Faults are seen on this geologic map cutting across rock layers. When rock layers are tilted, you will see stripes of each layer on the map. There are symbols on a geologic map that tell you which direction the rock layers slant, and often there is a cut away diagram, called a cross section, that shows what the rock layers look like below the surface. A large-scale geologic map will just show geologic provinces. They do not show the detail of individual rock layers. "
on a topographic map,(A) Contour intervals are always set at a standard 20 feet (B) Contour lines are the closest together on the steepest slopes (C) No human settlements or roads are shown (D) All of the above,B,"As we mentioned above, topographic maps show the shape of the land. You can determine a lot of information about the landscape using a topographic map. These maps are invaluable for Earth scientists. "
"if i wanted to know how deep lake tahoe is, i would use this map.",(A) Geological map (B) Topographic map (C) Globe (D) Bathymetric map,D,"Oceanographers use a type of topographic map that shows water depths (Figure 2.32). On this map, the contour lines represent depth below the surface. Therefore, high numbers are deeper depths and low numbers are shallow depths. These maps are made from depth soundings or sonar data. They help oceanographers understand the shape of bottoms of lakes, bays, and the ocean. This information also helps boaters navigate safely. "
"if i wanted to find the san andreas fault in california, i would use this map.",(A) Bathymetric map (B) Geologic map (C) Topographic map (D) Contour map,B,"The San Andreas Fault in California is a right-lateral strike-slip fault (Figure 7.15). It is also a transform fault because the San Andreas is a plate boundary. As you can see, California will not fall into the ocean someday. The land west of the San Andreas Fault is moving northeastward, while the North American plate moves southwest. Someday, millions of years from now, Los Angeles will be a suburb of San Francisco! "
mars is the _____ planet from the sun.,(A) Furthest (B) Fourth (C) First (D) None of the above,B,"Mars is the fourth planet from the Sun, and the first planet beyond Earths orbit (Figure 1.1). Mars is a quite different from Earth and yet more similar than any other planet. Mars is smaller, colder, drier, and appears to have no life, but volcanoes are common to both planets and Mars has many. Mars is easy to observe, so Mars has been studied more thoroughly than any other extraterrestrial planet. Space probes, rovers, and orbiting satellites have all yielded information to planetary geologists. Although no humans have ever set foot on Mars, both NASA and the European Space Agency have set goals of sending people to Mars sometime between 2030 and 2040. This image of Mars, taken by the Hubble Space Telescope in October, 2005, shows the planets red color, a small ice cap on the south pole, and a dust storm. "
mars is nicknamed the red planet because of _________ in the soil.,(A) Blood (B) Carbon dioxide (C) Ozone (D) Iron oxide,D,"Viewed from Earth, Mars is red. This is due to large amounts of iron in the soil. The ancient Greeks and Romans named the planet Mars after the god of war. The planets red color reminded them of blood. Mars has only a very thin atmosphere, made up mostly of carbon dioxide. "
mars is the only planet that humans have walked on.,(A) True (B) False,B,"Mars is the fourth planet from the Sun, and the first planet beyond Earths orbit (Figure 1.1). Mars is a quite different from Earth and yet more similar than any other planet. Mars is smaller, colder, drier, and appears to have no life, but volcanoes are common to both planets and Mars has many. Mars is easy to observe, so Mars has been studied more thoroughly than any other extraterrestrial planet. Space probes, rovers, and orbiting satellites have all yielded information to planetary geologists. Although no humans have ever set foot on Mars, both NASA and the European Space Agency have set goals of sending people to Mars sometime between 2030 and 2040. This image of Mars, taken by the Hubble Space Telescope in October, 2005, shows the planets red color, a small ice cap on the south pole, and a dust storm. "
the martian atmosphere,(A) Has a large percentage of carbon dioxide (B) Has a strong greenhouse effect (C) Could support life as we know it (D) All of these,A,"Viewed from Earth, Mars is reddish in color. The ancient Greeks and Romans named the planet after the god of war. The surface is not red from blood but from large amounts of iron oxide in the soil. The Martian atmosphere is very thin relative to Earths and has much lower atmospheric pressure. Although the atmosphere is made up mostly of carbon dioxide, the planet has only a weak greenhouse effect, so temperatures are only slightly higher than if the planet had no atmosphere. "
"the martian shield volcano, olympus mons,",(A) Was formed at a hotspot (B) like the Hawaiian volcanoes (C) b Is the largest mountain in the solar system (D) c Has a crater lake on its summit (E) d All of the above,B,"Mars has mountains, canyons, and other features similar to Earth. Some of these surface features are amazing for their size! Olympus Mons is a shield volcano, similar to the volcanoes that make up the Hawaiian Islands. But Olympus Mons is also the largest mountain in the solar system (Figure 1.2). Mars also has the largest canyon in the solar system, Valles Marineris (Figure 1.3). "
the largest canyon in the solar system called valles marineris is found on mars.,(A) True (B) False,A,"Mars has mountains, canyons, and other features similar to Earth. Some of these surface features are amazing for their size! Olympus Mons is a shield volcano, similar to the volcanoes that make up the Hawaiian Islands. But Olympus Mons is also the largest mountain in the solar system (Figure 1.2). Mars also has the largest canyon in the solar system, Valles Marineris (Figure 1.3). "
water cannot stay in liquid form on mars because the,(A) Temperature is too high (B) Atmospheric pressure is too low (C) Water is actually liquid methane (D) All of the above,B,"Water on Mars cant be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when volcanoes erupt. At this times liquid water flows across the surface. Scientists think that there was once liquid water on the planet. There are many surface features that look like water- eroded canyons. The Mars rover collected round clumps of crystals that, on Earth, usually form in water. If there was liquid water on Mars, life might have existed there in the past. "
how many moons does mars have? what are their names?,(A) 3; Demtrus (B) Claudius (C) Mark (D) b 2; Pheobe (E) Demo (F) c 2; Phobos (G) Deimos (H) d 4; Zeus (I) Venus (J) Zacharia (K) Joseph,C,"Mars has two very small, irregular moons, Phobos (seen in Figure 25.18) and Deimos. These moons were discovered in 1877. They are named after the two sons of Ares, who followed their father into war. The moons were probably asteroids that were captured by Martian gravity. "
mars has active plate tectonics.,(A) True (B) False,B,"The Earth is divided into many plates. These plates move around on the surface. The plates collide or slide past each other. One may even plunge beneath another. Plate motions cause most geological activity. This activity includes earthquakes, volcanoes, and the buildup of mountains. The reason for plate movement is convection in the mantle. Earth is the only planet that we know has plate tectonics. "
microbial life has been found in the ices of mars.,(A) True (B) False,B,"Water on Mars cant be a liquid. This is because the pressure of the atmosphere is too low. The planet does have a lot of water; it is in the form of ice. The south pole of Mars has a very visible ice cap. Scientists also have evidence that there is also a lot of ice just under the Martian surface. The ice melts when volcanoes erupt. At this times liquid water flows across the surface. Scientists think that there was once liquid water on the planet. There are many surface features that look like water- eroded canyons. The Mars rover collected round clumps of crystals that, on Earth, usually form in water. If there was liquid water on Mars, life might have existed there in the past. "
a seismograph from an earthquake with an epicenter about 200 miles away shows,(A) A large arrival for the first P-waves and then a tapering off (B) A large arrival for the first P-waves (C) then a falling off (D) then a large arrival for the first S- (E) c A small arrival for the first P-waves then a large arrival for the first S-waves (F) d Random arrivals of waves,B,"One seismogram indicates the distance to the epicenter. This is determined by the P-and S-wave arrival times. If a quake is near the seismograph, the S-waves arrive shortly after the P-waves. If a quake is far from the seismograph, the P-waves arrive long before the S-waves. The longer the time is between the P-and S-wave arrivals, the further away the earthquake was from the seismograph. First, seismologists calculate the arrival time difference. Then they know the distance to the epicenter from that seismograph. Next, the seismologists try to determine the location of the earthquake epicenter. To do this they need the distances to the epicenter from at least three seismographs. Lets say that they know that an earthquakes epicenter is 50 kilometers from Kansas City. They draw a circle with a 50 km radius around that seismic station. They do this twice more around two different seismic stations. The three circles intersect at a single point. This is the earthquakes epicenter (Figure 7.35). "
the first wave produced by an earthquake is called,(A) A primary wave (B) A secondary wave (C) A first wave (D) None of the above,A,"Earthquakes cause longitudinal waves as well as transverse waves. The disturbance that causes an earthquake sends longitudinal waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called primary, or P, waves. They are illustrated in Figure 19.7. "
a seismogram produces a graph-like representation of the seismic waves it receives and records them onto a seismograph.,(A) True (B) False,B,"A seismograph produces a graph-like representation of the seismic waves it receives and records them onto a seismogram (Figure 1.1). Seismograms contain information that can be used to determine how strong an earthquake was, how long it lasted, and how far away it was. Modern seismometers record ground motions using electronic motion detectors. The data are then kept digitally on a computer. If a seismogram records P-waves and surface waves but not S-waves, the seismograph was on the other side of the Earth from the earthquake. The amplitude of the waves can be used to determine the magnitude of the earthquake, which will be discussed in a later section. "
surface waves are hard to find on a seismograph because they,(A) Don’t travel through liquid (B) Are very small (C) Arrive before the primary waves when no one is looking (D) Arrive very shortly after the secondary waves,D,"Seismograms contain a lot of information about an earthquake: its strength, length and distance. Wave height used to determine the magnitude of the earthquake. The seismogram shows the different arrival times of the seismic waves (Figure 7.34). The first waves are P-waves since they are the fastest. S-waves come in next and are usually larger than P-waves. The surface waves arrive just after the S-waves. If the earthquake has a shallow focus, the surface waves are the largest ones recorded. A seismogram may record P-waves and surface waves, but not S-waves. This means that it was located more than halfway around the Earth from the earthquake. The reason is that Earths outer core is liquid. S-waves cannot travel "
"to locate an earthquakes epicenter, you need to know the distance to the epicenter from at least __________ seismic station.",(A) One (B) Two (C) Three (D) Four or more,C,"One seismogram indicates the distance to the epicenter. This is determined by the P-and S-wave arrival times. If a quake is near the seismograph, the S-waves arrive shortly after the P-waves. If a quake is far from the seismograph, the P-waves arrive long before the S-waves. The longer the time is between the P-and S-wave arrivals, the further away the earthquake was from the seismograph. First, seismologists calculate the arrival time difference. Then they know the distance to the epicenter from that seismograph. Next, the seismologists try to determine the location of the earthquake epicenter. To do this they need the distances to the epicenter from at least three seismographs. Lets say that they know that an earthquakes epicenter is 50 kilometers from Kansas City. They draw a circle with a 50 km radius around that seismic station. They do this twice more around two different seismic stations. The three circles intersect at a single point. This is the earthquakes epicenter (Figure 7.35). "
seismograms contain information that can be used to determine,(A) How strong an earthquake was (B) How long an earthquake lasted (C) How far the earthquake was (D) All of the above,D,"Seismograms contain a lot of information about an earthquake: its strength, length and distance. Wave height used to determine the magnitude of the earthquake. The seismogram shows the different arrival times of the seismic waves (Figure 7.34). The first waves are P-waves since they are the fastest. S-waves come in next and are usually larger than P-waves. The surface waves arrive just after the S-waves. If the earthquake has a shallow focus, the surface waves are the largest ones recorded. A seismogram may record P-waves and surface waves, but not S-waves. This means that it was located more than halfway around the Earth from the earthquake. The reason is that Earths outer core is liquid. S-waves cannot travel "
the amplitude is,(A) The distance of the top of one wave to the top of the next wave (B) Between the highest peak and lowest trough of a wave (C) The length of time that it took for the seismic waves came in (D) The distance between the P-wave and S-wave first arrival,B,"Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. The resting position of a particle of the medium is where the particle would be in the absence of a wave. The Figure 1.1 show the amplitudes of two different types of waves: transverse and longitudinal waves. In a transverse wave, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave. In a longitudinal wave, particles of the medium move back and forth in the same direction as the wave. Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. The closer together the particles are, the greater the amplitude of the wave. Q: What do you think determines a waves amplitude? A: Wave amplitude is determined by the energy of the disturbance that causes the wave. "
the wavelength of the waves can be used to determine the magnitude of an earthquake.,(A) True (B) False,B,"Seismograms contain a lot of information about an earthquake: its strength, length and distance. Wave height used to determine the magnitude of the earthquake. The seismogram shows the different arrival times of the seismic waves (Figure 7.34). The first waves are P-waves since they are the fastest. S-waves come in next and are usually larger than P-waves. The surface waves arrive just after the S-waves. If the earthquake has a shallow focus, the surface waves are the largest ones recorded. A seismogram may record P-waves and surface waves, but not S-waves. This means that it was located more than halfway around the Earth from the earthquake. The reason is that Earths outer core is liquid. S-waves cannot travel "
seismograph that records p-waves but not s-waves is,(A) Malfunctioning (B) Very far away from the earthquake (C) On the other side of the planet from the earthquake (D) The wrong type of recorder to use on this type of earthquake,C,"A seismograph produces a graph-like representation of the seismic waves it receives and records them onto a seismogram (Figure 1.1). Seismograms contain information that can be used to determine how strong an earthquake was, how long it lasted, and how far away it was. Modern seismometers record ground motions using electronic motion detectors. The data are then kept digitally on a computer. If a seismogram records P-waves and surface waves but not S-waves, the seismograph was on the other side of the Earth from the earthquake. The amplitude of the waves can be used to determine the magnitude of the earthquake, which will be discussed in a later section. "
what is the difference between a seismograph and a modern seismometer?,(A) A seismograph records on a seismogram; a seismometer records digitally (B) A seismograph needs to record more seismic stations than a seismometer (C) A seismograph does not give the location of the epicenter but a seismometer does (D) All of the above,A,"A seismograph produces a graph-like representation of the seismic waves it receives and records them onto a seismogram (Figure 1.1). Seismograms contain information that can be used to determine how strong an earthquake was, how long it lasted, and how far away it was. Modern seismometers record ground motions using electronic motion detectors. The data are then kept digitally on a computer. If a seismogram records P-waves and surface waves but not S-waves, the seismograph was on the other side of the Earth from the earthquake. The amplitude of the waves can be used to determine the magnitude of the earthquake, which will be discussed in a later section. "
what can cause mechanical weathering?,(A) Animals (B) Ice (C) Gravity (D) All of the above,D,"Sometimes biological elements cause mechanical weathering. This can happen slowly. A plants roots grow into a crack in rock. As the roots grow larger, they wedge open the crack. Burrowing animals can also cause weathering. By digging for food or creating a hole to live in the animal may break apart rock. Today, human beings do a lot of mechanical weathering whenever we dig or blast into rock. This is common when we build homes, roads, and subways, or quarry stone for construction or other uses. "
"water that enters a crack, expands the crack as it freezes, and splits it apart.",(A) Abrasion (B) Wind erosion (C) Water erosion (D) Ice wedging,D,"Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) "
the most common form of mechanical weathering in locations like the eastern and midwestern united states and the mountains of california is,(A) Water erosion (B) Ice wedging (C) Abrasion (D) Wind erosion,B,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
mechanical weathering breaks down existing rocks by,(A) Changing them chemically (B) but not physically (C) b Changing them physically (D) but not chemically (E) c Changing them chemically and physically (F) d Incorporating them into new rocks,B,"Mechanical weathering (also called physical weathering) breaks rock into smaller pieces. These smaller pieces are just like the bigger rock, but smaller. That means the rock has changed physically without changing its composition. The smaller pieces have the same minerals, in just the same proportions as the original rock. "
which of these can cause abrasion?,(A) Animals (B) Plants (C) Gravity (D) All of the above,C,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
which of these are signs of abrasion?,(A) Scratches from rocks in a moving glacier (B) Rocks changing color (C) Iron turning into rust (D) Cracks made by ice,A,"Abrasion is another form of mechanical weathering. In abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a mountainside or cliff. Moving water causes abrasion as particles in the water collide and bump against one another. Strong winds carrying pieces of sand can sandblast surfaces. Ice in glaciers carries many bits and pieces of rock. Rocks embedded at the bottom of the glacier scrape against the rocks below. Abrasion makes rocks with sharp or jagged edges smooth and round. If you have ever collected beach glass or cobbles from a stream, you have witnessed the work of abrasion (Figure 1.2). "
put the steps of ice wedging in order. i. water freezes ii. water seeps into cracks iii. frozen water expands the rock iv. water thaws and over time the rock breaks into pieces,(A) IV (B) III (C) II (D) I (E) b IV (F) II (G) I (H) III (I) c II (J) I (K) III (L) IV (M) d II (N) III (O) I (P) IV,C,"Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) "
ice wedging is common at where temperatures commonly vary between above and below freezing.,(A) True (B) False,A,"Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) "
moving water can cause abrasion by,(A) Making rocks tumble down a slope (B) Striking the rock (C) Sandblasting the rock (D) None of these,A,"Abrasion is another type of mechanical weathering. With abrasion, one rock bumps against another rock. Gravity causes abrasion as a rock tumbles down a slope. Moving water causes abrasion it moves rocks so that they bump against one another (Figure 9.3). Strong winds cause abrasion by blasting sand against rock surfaces. Finally, the ice in glaciers cause abrasion. Pieces of rock embedded in ice at the bottom of a glacier scrape against the rock below. If you have ever collected beach glass or pebbles from a stream, you have witnessed the work of abrasion. "
mechanical weathering includes,(A) Plant roots growing into a crack and widening it (B) Burrowing animals breaking rock as they dig (C) Humans digging up rock for construction (D) All of these,D,"Mechanical weathering breaks rock into smaller pieces. These smaller pieces are just like the bigger rock; they are just smaller! The rock has broken without changing its composition. The smaller pieces have the same minerals in the same proportions. You could use the expression a chip off the old block to describe mechanical weathering! The main agents of mechanical weathering are water, ice, and wind. "
"compared to earth, mercury has __________ years and __________ days.",(A) Long; short (B) Short; short (C) Short; long (D) Long; long,C,"Mercury is named for the Roman messenger god, who could run extremely quickly, just as the planet moves very quickly in its orbit around the Sun. A year on Mercury  the length of time it takes to orbit the Sun  is just 88 Earth days. Despite its very short years, Mercury has very long days. A day is defined as the time it takes a planet to turn on its axis. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 57 Earth days long. In other words, on Mercury, a year is only a Mercury day and a half long! "
which of the following is true about mercury?,(A) The planet has two moons (B) The surface has been smoothed over by lava flows in recent geologic history (C) The planet has a thick atmosphere (D) The planet has an orbital period that is about one-quarter that of Earth,D,"Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. "
mercurys surface,(A) Is covered with impact craters (B) Hasn’t changed much geologically for billions of years (C) Has undergone very little weathering and erosion (D) All of these,D,"Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. "
planet mercury was named for the roman god mercury because it appears to travel rapidly across the face of the sun.,(A) True (B) False,A,"Mercury is named for the Roman messenger god. Mercury was a messenger because he could run extremely fast. The Greeks gave the planet this name because Mercury moves very quickly in its orbit around the Sun. Mercury orbits the Sun in just 88 Earth days. Mercury has a very short year, but it also has very long days. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 58 Earth days long. "
"on mercury, each year lasts only 1-1/2 days.",(A) True (B) False,A,"Mercury is named for the Roman messenger god, who could run extremely quickly, just as the planet moves very quickly in its orbit around the Sun. A year on Mercury  the length of time it takes to orbit the Sun  is just 88 Earth days. Despite its very short years, Mercury has very long days. A day is defined as the time it takes a planet to turn on its axis. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 57 Earth days long. In other words, on Mercury, a year is only a Mercury day and a half long! "
mercury is the closest planet to earth.,(A) True (B) False,B,"The smallest planet, Mercury, is the planet closest to the Sun. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. However, the Mariner 10 spacecraft, shown in Figure 1.1, visited Mercury from 1974 to 1975. The MESSENGER spacecraft has been studying Mercury in detail since 2005. The craft is currently in orbit around the planet, where it is creating detailed maps. MESSENGER stands for Mercury Surface, Space Environment, Geochemistry and Ranging. (a) Mariner 10 made three flybys of Mercury in 1974 and 1975. (b) A 2008 image of compiled from a flyby by MESSENGER. As Figure 1.2 shows, the surface of Mercury is covered with craters, like Earths Moon. Ancient impact craters means that for billions of years Mercury hasnt changed much geologically. Also, with very little atmosphere, the processes of weathering and erosion do not wear down structures on the planet. "
temperatures on mercury are __________ because mercury __________.,(A) Extreme; has almost no atmosphere (B) Moderate; has a thick atmosphere (C) Similar to Earth’s; has an Earth-like atmosphere (D) Extreme; has a thick atmosphere,A,"Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. "
the core of mercury is made mostly of melted,(A) Sulfur (B) Iron (C) Mercury (D) Silver,B,"Figure 1.3 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Its relatively large, liquid core, made mostly of melted iron, takes up about 42% of the planets volume. "
"because mercury has a large core, the planet is",(A) Large (B) Dense (C) Geologically dead (D) All of these,B,"Figure 1.3 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Its relatively large, liquid core, made mostly of melted iron, takes up about 42% of the planets volume. "
"because mercury is so close to the sun, the entire planet is scorching hot.",(A) True (B) False,B,"Mercury is close to the Sun, so it can get very hot. However, Mercury has virtually no atmosphere, no water to insulate the surface, and it rotates very slowly. For these reasons, temperatures on the surface of Mercury vary widely. In direct sunlight, the surface can be as hot as 427 C (801 F). On the dark side, or in the shadows inside craters, the surface can be as cold as -183 C (-297 F)! Although most of Mercury is extremely dry, scientists think Mercury is covered with craters, like Earths Moon. MESSENGER has taken extremely detailed pictures of the planets surface. there may be a small amount of water in the form of ice at the poles of Mercury, in areas that never receive direct sunlight. "
mercury is released into the atmosphere when this is burned.,(A) Wood (B) Water (C) Coal (D) None of the above,C,"Mercury is released into the atmosphere when coal is burned (Figure 1.1). But breathing the mercury is not harmful. In the atmosphere, the mercury forms small droplets that are deposited in water or sediments. "
ingested mercury gets stored in which part of the body?,(A) The skin (B) The bones (C) Nerve cells (D) Fat,D,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
from what activity did the mercury in san francisco bays mud originate?,(A) Placer gold mining (B) Fishing (C) Construction of the Bay Bridge and Golden Gate Bridge (D) Paint manufacturing,A,"Wastewater from cities and towns contains many different contaminants from many different homes, businesses, and industries (Figure 1.1). Contaminants come from: Sewage disposal (some sewage is inadequately treated or untreated). Storm drains. Septic tanks (sewage from homes). Boats that dump sewage. Yard runoff (fertilizer and herbicide waste). Large numbers of sewage spills into San Francisco Bay are forcing cities, water agencies and the public to take a closer look at wastewater and its impacts on the health of the bay. QUEST investigates the causes of the spills and whats being done to prevent them. Click image to the left or use the URL below. URL: "
what is bioaccumulation?,(A) When a substance decreases in concentration up the food chain (B) When a substance accumulates in an organisms body over its lifetime (C) When a substance is converted to a toxic substance by a living organism (D) All of these,B,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
methyl mercury can _______________.,(A) Poison the nervous system (B) Cause brain damage (C) Delay development (D) All of the above,D,"Methyl mercury poisoning can cause nervous system or brain damage, especially in infants and children. Children may experience brain damage or developmental delays. The phrase mad as a hatter was common when Lewis Carroll wrote his Alice in Wonderland stories. It was based on symptoms suffered by hatters who were exposed to mercury and experienced mercury poisoning while using the metal to make hats (Figure 1.3). Like mercury, other metals and VOCS can bioaccumulate, causing harm to animals and people high on the food chain. Mercury, a potent neurotoxin, has been flowing into the San Francisco Bay since the Gold Rush Era. It has settled in the bays mud and made its way up the food chain, endangering wildlife and making many fish unsafe to eat. Now a multi-billion-dollar plan aims to clean it up. Click image to the left or use the URL below. URL: "
"mercury poisoning can drive a person to be as mad as a hatter, which is based off of this novel.",(A) Tale of Two Cites (B) Harry Potter (C) Lord of the Rings (D) Alice in Wonderland,D,"Methyl mercury poisoning can cause nervous system or brain damage, especially in infants and children. Children may experience brain damage or developmental delays. The phrase mad as a hatter was common when Lewis Carroll wrote his Alice in Wonderland stories. It was based on symptoms suffered by hatters who were exposed to mercury and experienced mercury poisoning while using the metal to make hats (Figure 1.3). Like mercury, other metals and VOCS can bioaccumulate, causing harm to animals and people high on the food chain. Mercury, a potent neurotoxin, has been flowing into the San Francisco Bay since the Gold Rush Era. It has settled in the bays mud and made its way up the food chain, endangering wildlife and making many fish unsafe to eat. Now a multi-billion-dollar plan aims to clean it up. Click image to the left or use the URL below. URL: "
mercury is a potent neurotoxin.,(A) True (B) False,A,"Methyl mercury poisoning can cause nervous system or brain damage, especially in infants and children. Children may experience brain damage or developmental delays. The phrase mad as a hatter was common when Lewis Carroll wrote his Alice in Wonderland stories. It was based on symptoms suffered by hatters who were exposed to mercury and experienced mercury poisoning while using the metal to make hats (Figure 1.3). Like mercury, other metals and VOCS can bioaccumulate, causing harm to animals and people high on the food chain. Mercury, a potent neurotoxin, has been flowing into the San Francisco Bay since the Gold Rush Era. It has settled in the bays mud and made its way up the food chain, endangering wildlife and making many fish unsafe to eat. Now a multi-billion-dollar plan aims to clean it up. Click image to the left or use the URL below. URL: "
mercury becomes harmful when it,(A) Drops to the ground and is ingested by organisms (B) Is converted by bacteria to methyl mercury (C) Is eaten by small fish (D) All of these,B,"Mercury is released into the atmosphere when coal is burned (Figure 1.1). But breathing the mercury is not harmful. In the atmosphere, the mercury forms small droplets that are deposited in water or sediments. "
all substances bioaccumulate.,(A) True (B) False,B,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
it is it better to eat fish that are low on the food chain than the large predatory fish because their bodies contain less mercury.,(A) True (B) False,A,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
the pressure in the mesosphere is so low that the liquids would boil at normal body temperature.,(A) True (B) False,A,"The air in the mesosphere has extremely low density: 99.9% of the mass of the atmosphere is below the mesosphere. As a result, air pressure is very low (Figure 1.1). A person traveling through the mesosphere would experience severe burns from ultraviolet light since the ozone layer, which provides UV protection, is in the stratosphere below. There would be almost no oxygen for breathing. And, of course, your blood would boil at normal body temperature. Click image to the left or use the URL below. URL: "
meteors burn up in the mesosphere. how can this happen?,(A) The mesosphere is so hot (remember (B) your blood would boil (C) b A meteor travels so fast that it experiences friction from a lot of air molecules (D) c Meteors burn up when they run into the clouds found in the mesosphere (E) d A & B,B,"Did you ever see a meteor shower, like the one in Figure 15.15? Meteors burn as they fall through the mesosphere. The space rocks experience friction with the gas molecules. The friction makes the meteors get very hot. Many meteors burn up completely in the mesosphere. "
"although the temperature of the mesosphere is extremely low, a persons blood would boil at normal body temperature.",(A) True (B) False,A,"The air in the mesosphere has extremely low density: 99.9% of the mass of the atmosphere is below the mesosphere. As a result, air pressure is very low (Figure 1.1). A person traveling through the mesosphere would experience severe burns from ultraviolet light since the ozone layer, which provides UV protection, is in the stratosphere below. There would be almost no oxygen for breathing. And, of course, your blood would boil at normal body temperature. Click image to the left or use the URL below. URL: "
"the highest temperature in the mesosphere is at the top, which is -90oc.",(A) True (B) False,B,At the top of the mesosphere is the mesopause. Temperatures here are colder than anywhere else in the atmosphere. They are as low as -100 C (-212 F)! Nowhere on Earths surface is that cold. 
what is the heat source for the mesosphere?,(A) The troposphere (B) The Sun (C) The mesosphere (D) The stratosphere,D,There are very few gas molecules in the mesosphere. This means that there is little matter to absorb the Suns rays and heat the air. Most of the heat that enters the mesosphere comes from the stratosphere below. Thats why the mesosphere is warmest at the bottom. 
what type of clouds can be found in the mesosphere?,(A) Nimbus (B) Cumulous (C) Noctilucent (D) Stratus,C,The mesosphere is the layer above the stratosphere. It rises to about 85 kilometers (53 miles) above the surface. Temperature decreases with altitude in this layer. 
why would an astronaut without a spacesuit get severe ultraviolet burns in the mesosphere (besides having a lot of other problems)?,(A) The protective ozone layer is below her (B) The sun is hotter there (C) Her blood would be boiling (D) A & B,A,"The air in the mesosphere has extremely low density: 99.9% of the mass of the atmosphere is below the mesosphere. As a result, air pressure is very low (Figure 1.1). A person traveling through the mesosphere would experience severe burns from ultraviolet light since the ozone layer, which provides UV protection, is in the stratosphere below. There would be almost no oxygen for breathing. And, of course, your blood would boil at normal body temperature. Click image to the left or use the URL below. URL: "
the ____________ layer is above the mesosphere and the ______________ is below.,(A) Stratosphere (B) Troposphere (C) b Thermosphere (D) Stratosphere (E) c Thermosphere (F) Troposphere (G) d Troposphere (H) Thermosphere,B,The mesosphere is the layer above the stratosphere. It rises to about 85 kilometers (53 miles) above the surface. Temperature decreases with altitude in this layer. 
the density of the mesosphere is very low because,(A) Only 01% of the mass of the atmosphere is in or above the mesosphere (B) The mesosphere is very cold (C) The air pressure is very high (D) Ultraviolet radiation mixes up the gases,A,"The air in the mesosphere has extremely low density: 99.9% of the mass of the atmosphere is below the mesosphere. As a result, air pressure is very low (Figure 1.1). A person traveling through the mesosphere would experience severe burns from ultraviolet light since the ozone layer, which provides UV protection, is in the stratosphere below. There would be almost no oxygen for breathing. And, of course, your blood would boil at normal body temperature. Click image to the left or use the URL below. URL: "
slate is a metamorphic rock made from,(A) Granite (B) Limestone (C) Shale (D) Sandstone,C,"Table 1.1 shows some common metamorphic rocks and their original parent rock. Picture Rock Name Slate Type of Rock Foliated Metamorphic Comments Phyllite Foliated Metamorphism of slate, but under greater heat and pressure than slate Schist Foliated Often derived from meta- morphism of claystone or shale; metamorphosed under more heat and pres- sure than phyllite Gneiss Foliated Metamorphism of various different rocks, under ex- treme conditions of heat and pressure Hornfels Non-foliated Contact metamorphism of various different rock types Metamorphism of shale Picture Rock Name Comments Quartzite Type of Metamorphic Rock Non-foliated Marble Non-foliated Metamorphism of lime- stone Metaconglomerate Non-foliated Metamorphism of con- glomerate Metamorphism of quartz sandstone Click image to the left or use the URL below. URL: "
the difference in rocks from slate to phyllite to schist to gneiss is an increase in,(A) The size of the crystals of the parent rock (B) Silica (C) Heat and pressure of metamorphism (D) The number of mafic minerals,C,"Table 1.1 shows some common metamorphic rocks and their original parent rock. Picture Rock Name Slate Type of Rock Foliated Metamorphic Comments Phyllite Foliated Metamorphism of slate, but under greater heat and pressure than slate Schist Foliated Often derived from meta- morphism of claystone or shale; metamorphosed under more heat and pres- sure than phyllite Gneiss Foliated Metamorphism of various different rocks, under ex- treme conditions of heat and pressure Hornfels Non-foliated Contact metamorphism of various different rock types Metamorphism of shale Picture Rock Name Comments Quartzite Type of Metamorphic Rock Non-foliated Marble Non-foliated Metamorphism of lime- stone Metaconglomerate Non-foliated Metamorphism of con- glomerate Metamorphism of quartz sandstone Click image to the left or use the URL below. URL: "
"hornfels, quartzite and marble are all foliated.",(A) True (B) False,B,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
"the more extreme the amount of metamorphism, the easier it is to tell what the original rock was.",(A) True (B) False,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
quartzite is a metamorphic rock made from this rock.,(A) Shale (B) Sandstone (C) Limestone (D) Granite,B,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
marble is metamorphosed sandstone.,(A) True (B) False,B,Quartzite and marble are the most commonly used metamorphic rocks. They are frequently chosen for building materials and artwork. Marble is used for statues and decorative items like vases (Figure 4.16). Quartzite is very hard and is often crushed and used in building railroad tracks. Schist and slate are sometimes used as building and landscape materials. 
gneiss displays bands because it,(A) Has undergone extreme metamorphism (B) Is metamorphosed layered sedimentary rock (C) Is metamorphosed hornfels (D) Is chemically altered,A,"Magma heats nearby underground water, which reacts with the rocks around it to pick up dissolved particles. As the water flows through open spaces in the rock and cools, it deposits solid minerals. The mineral deposits that form when a mineral fills cracks in rocks are called veins (Figure 1.4). Quartz veins formed in this rock. When minerals are deposited in open spaces, large crystals form (Figure 1.5). Amethyst formed when large crystals grew in open spaces inside the rock. These special rocks are called geodes. "
metamorphism of limestone turns into this rock.,(A) Gneiss (B) Hornfels (C) Quartzite (D) Marble,D,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
metaconglomerate is non-foliated and displays the pebbles that were part of it when it was a sedimentary rock.,(A) True (B) False,A,"Table 1.1 shows some common metamorphic rocks and their original parent rock. Picture Rock Name Slate Type of Rock Foliated Metamorphic Comments Phyllite Foliated Metamorphism of slate, but under greater heat and pressure than slate Schist Foliated Often derived from meta- morphism of claystone or shale; metamorphosed under more heat and pres- sure than phyllite Gneiss Foliated Metamorphism of various different rocks, under ex- treme conditions of heat and pressure Hornfels Non-foliated Contact metamorphism of various different rock types Metamorphism of shale Picture Rock Name Comments Quartzite Type of Metamorphic Rock Non-foliated Marble Non-foliated Metamorphism of lime- stone Metaconglomerate Non-foliated Metamorphism of con- glomerate Metamorphism of quartz sandstone Click image to the left or use the URL below. URL: "
this metamorphic rock derived from clay.,(A) Slate (B) Phyllite (C) Schist (D) All of the above,D,"Table 1.1 shows some common metamorphic rocks and their original parent rock. Picture Rock Name Slate Type of Rock Foliated Metamorphic Comments Phyllite Foliated Metamorphism of slate, but under greater heat and pressure than slate Schist Foliated Often derived from meta- morphism of claystone or shale; metamorphosed under more heat and pres- sure than phyllite Gneiss Foliated Metamorphism of various different rocks, under ex- treme conditions of heat and pressure Hornfels Non-foliated Contact metamorphism of various different rock types Metamorphism of shale Picture Rock Name Comments Quartzite Type of Metamorphic Rock Non-foliated Marble Non-foliated Metamorphism of lime- stone Metaconglomerate Non-foliated Metamorphism of con- glomerate Metamorphism of quartz sandstone Click image to the left or use the URL below. URL: "
which of these rocks can become a metamorphic rock?,(A) Igneous (B) Sedimentary (C) Metamorphic (D) All of the above,D,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
foliation forms in some metamorphic rocks because,(A) Pressure is exerted in one direction (B) Pressure from overlying rock (C) Extreme heat from magma (D) Ions move between minerals,A,"Extreme pressure may also lead to foliation, the flat layers that form in rocks as the rocks are squeezed by pressure (Figure 1.1). Foliation normally forms when pressure is exerted in only one direction. Metamorphic rocks may also be non-foliated. Quartzite and marble, shown in the concept ""Metamorphic Rock Classification,"" are non-foliated. A foliated metamorphic rock. "
metamorphic rocks are altered by heat and pressure.,(A) True (B) False,A,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
minerals metamorphose because they need to be stable under new temperature and pressure conditions.,(A) True (B) False,A,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
which of these metamorphic rocks is foliated?,(A) Quartzite (B) Gneiss (C) Marble (D) All of these,B,"Table 1.1 shows some common metamorphic rocks and their original parent rock. Picture Rock Name Slate Type of Rock Foliated Metamorphic Comments Phyllite Foliated Metamorphism of slate, but under greater heat and pressure than slate Schist Foliated Often derived from meta- morphism of claystone or shale; metamorphosed under more heat and pres- sure than phyllite Gneiss Foliated Metamorphism of various different rocks, under ex- treme conditions of heat and pressure Hornfels Non-foliated Contact metamorphism of various different rock types Metamorphism of shale Picture Rock Name Comments Quartzite Type of Metamorphic Rock Non-foliated Marble Non-foliated Metamorphism of lime- stone Metaconglomerate Non-foliated Metamorphism of con- glomerate Metamorphism of quartz sandstone Click image to the left or use the URL below. URL: "
the chemical composition of minerals changes during metamorphism because ions move between minerals.,(A) True (B) False,B,"Any type of rock - igneous, sedimentary, or metamorphic  can become a metamorphic rock. All that is needed is enough heat and/or pressure to alter the existing rocks physical or chemical makeup without melting the rock entirely. Rocks change during metamorphism because the minerals need to be stable under the new temperature and pressure conditions. The need for stability may cause the structure of minerals to rearrange and form new minerals. Ions may move between minerals to create minerals of different chemical composition. Hornfels, with its alternating bands of dark and light crystals, is a good example of how minerals rearrange themselves during metamorphism. Hornfels is shown in the table for the ""Metamorphic Rock Classification"" concept. "
the type of metamorphism occurs over a large area.,(A) Contact metamorphism (B) Local metamorphism (C) Geological metamorphism (D) Regional metamorphism,D,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
contact metamorphism takes place because a rock is,(A) Deeply buried (B) Being squeezed from above (C) Adjacent to a magma body (D) Exposed to high pressure,C,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
"physical or chemical makeup, but not both, can change as a rock undergoes metamorphism.",(A) True (B) False,B,"When a rock is exposed to extreme heat and pressure within the Earth but does not melt, the rock becomes meta- morphosed. Metamorphism may change the mineral composition and the texture of the rock. For that reason, a metamorphic rock may have a new mineral composition and/or texture. "
the characteristics of regional metamorphism include,(A) Changes in a large amount of rock (B) Extreme high temperatures (C) Extreme high pressures (D) All of these,D,The two main types of metamorphism are both related to heat within Earth: 1. Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures. 2. Contact metamorphism: Changes in a rock that is in contact with magma. The changes occur because of the magmas extreme heat. Click image to the left or use the URL below. URL: 
what is a meteor?,(A) A shooting star (B) A dying star (C) A rock from space that burns up in Earth’s atmosphere (D) A star being pulled by Earth’s gravity,C,"A meteor, such as in Figure 1.1, is a streak of light across the sky. People call them shooting stars but they are actually small pieces of matter burning up as they enter Earths atmosphere from space. Meteors are called meteoroids before they reach Earths atmosphere. Meteoroids are smaller than asteroids and range from the size of boulders down to the size of tiny sand grains. Still smaller objects are called interplanetary dust. When Earth passes through a cluster of meteoroids, there is a meteor shower. These clusters are often remnants left behind by comet tails. "
a meteor appears as,(A) A streak of light across the sky (B) A rock that strikes the ground (C) Dust that flies through the atmosphere (D) None of these,A,"If you look at the sky on a dark night, you may see a meteor, like in Figure 25.33. A meteor forms a streak of light across the sky. People call them shooting stars because thats what they look like. But meteors are not stars at all. The light you see comes from a small piece of matter burning up as it flies through Earths atmosphere. "
a meteor shower is caused when earth,(A) Travels through the near-earth asteroid belt (B) Travels through the Kuiper belt (C) Passes near the Moon’s orbiting debris halo (D) Passes through the remnants of a comet’s tail,D,"A meteor, such as in Figure 1.1, is a streak of light across the sky. People call them shooting stars but they are actually small pieces of matter burning up as they enter Earths atmosphere from space. Meteors are called meteoroids before they reach Earths atmosphere. Meteoroids are smaller than asteroids and range from the size of boulders down to the size of tiny sand grains. Still smaller objects are called interplanetary dust. When Earth passes through a cluster of meteoroids, there is a meteor shower. These clusters are often remnants left behind by comet tails. "
"if an asteroid hits mars, bits can enter earths atmosphere as meteors.",(A) True (B) False,A,"Before these small pieces of matter enter Earths atmosphere, they are called meteoroids. Meteoroids are as large as boulders or as small as tiny sand grains. Larger objects are called asteroids; smaller objects are interplanetary dust. Meteoroids sometimes cluster together in long trails. They are the debris left behind by comets. When Earth passes through a comet trail, there is a meteor shower. During a meteor shower, there are many more meteors than normal for a night or two. "
meteoroids are meteors that enter earths atmosphere.,(A) True (B) False,B,"A meteor, such as in Figure 1.1, is a streak of light across the sky. People call them shooting stars but they are actually small pieces of matter burning up as they enter Earths atmosphere from space. Meteors are called meteoroids before they reach Earths atmosphere. Meteoroids are smaller than asteroids and range from the size of boulders down to the size of tiny sand grains. Still smaller objects are called interplanetary dust. When Earth passes through a cluster of meteoroids, there is a meteor shower. These clusters are often remnants left behind by comet tails. "
meteorites are,(A) Shooting stars (B) Meteors from Mars (C) Meteors that strikes Earth’s surface (D) Asteroids captured by Earth’s orbit,C,"Although most meteors burn up in the atmosphere, larger meteoroids may strike the Earths surface to create a meteorite. Meteorites are valuable to scientists because they provide clues about our solar system. Many meteorites are from asteroids that formed when the solar system formed (Figure 1.2). A few meteorites are made of rocky material that is thought to have come from Mars when an asteroid impact shot material off the Martian surface and into space. Click image to the left or use the URL below. URL: "
scientists believe that some meteorites that are made of rocky material come from ____________.,(A) The Sun (B) The Moon (C) Uranus (D) Venus,B,"Although most meteors burn up in the atmosphere, larger meteoroids may strike the Earths surface to create a meteorite. Meteorites are valuable to scientists because they provide clues about our solar system. Many meteorites are from asteroids that formed when the solar system formed (Figure 1.2). A few meteorites are made of rocky material that is thought to have come from Mars when an asteroid impact shot material off the Martian surface and into space. Click image to the left or use the URL below. URL: "
a meteoroid is dragged toward earth by ______ ; it burns up due to __________ with the atmosphere.,(A) Gravity (B) friction (C) b Friction (D) vaporization (E) c Gravity (F) vaporization (G) d Centrifugal force; friction,A,"A meteoroid is dragged towards Earth by gravity and enters the atmosphere. Friction with the atmosphere heats the object quickly, so it starts to vaporize. As it flies through the atmosphere, it leaves a trail of glowing gases. The object is now a meteor. Most meteors vaporize in the atmosphere. They never reach Earths surface. Large meteoroids may not burn up entirely in the atmosphere. A small core may remain and hit the Earths surface. This is called a meteorite. Meteorites provide clues about our solar system. Many were formed in the early solar system (Figure 25.34). Some are from asteroids that have split apart. A few are rocks from nearby bodies like Mars. For this to happen, an asteroid smashed into Mars and sent up debris. A bit of the debris entered Earths atmosphere as a meteor. "
meteorites from mars and the moon are the only rocks we have from those bodies.,(A) True (B) False,B,"Although most meteors burn up in the atmosphere, larger meteoroids may strike the Earths surface to create a meteorite. Meteorites are valuable to scientists because they provide clues about our solar system. Many meteorites are from asteroids that formed when the solar system formed (Figure 1.2). A few meteorites are made of rocky material that is thought to have come from Mars when an asteroid impact shot material off the Martian surface and into space. Click image to the left or use the URL below. URL: "
many meteorites were formed in the early solar system.,(A) True (B) False,A,Scientists study meteorites to learn about Earths interior. Meteorites formed in the early solar system. These objects represent early solar system materials. Some meteorites are made of iron and nickel. They are thought to be very similar to Earths core (Figure 6.2). An iron meteorite is the closest thing to a sample of the core that scientists can hold in their hands! 
astronomers estimate that the milky way contains _________.,(A) 100 to 200 billion stars (B) 200 to 400 billion stars (C) 400 to 600 billion stars (D) 600 to 800 billion stars,B,"The Milky Way Galaxy, which is our galaxy. The Milky Way is made of millions of stars along with a lot of gas and dust. It looks different from other galaxies because we are looking at the main disk from within the galaxy. Astronomers estimate that the Milky Way contains 200 to 400 billion stars. "
the milky way galaxy is a(n) ___________.,(A) Elliptical galaxy (B) Irregular galaxy (C) Circular galaxy (D) Spiral galaxy,D,"The Milky Way Galaxy, which is our galaxy. The Milky Way is made of millions of stars along with a lot of gas and dust. It looks different from other galaxies because we are looking at the main disk from within the galaxy. Astronomers estimate that the Milky Way contains 200 to 400 billion stars. "
the central bulge of our galaxy,(A) Contains mostly older stars and globular clusters (B) Is most likely to be spherical in shape (C) Is only a few light years wide (D) All of the above,A,"Although it is difficult to know what the shape of the Milky Way Galaxy is because we are inside of it, astronomers have identified it as a typical spiral galaxy containing about 200 billion to 400 billion stars (Figure 1.1). An artists rendition of what astronomers think the Milky Way Galaxy would look like seen from above. The Sun is located approximately where the arrow points. Like other spiral galaxies, our galaxy has a disk, a central bulge, and spiral arms. The disk is about 100,000 light- years across and 3,000 light-years thick. Most of the Galaxys gas, dust, young stars, and open clusters are in the disk. What evidence do astronomers find that lets them know that the Milky Way is a spiral galaxy? 1. The shape of the galaxy as we see it (Figure 1.2). 2. The velocities of stars and gas in the galaxy show a rotational motion. 3. The gases, color, and dust are typical of spiral galaxies. The central bulge is about 12,000 to 16,000 light-years wide and 6,000 to 10,000 light-years thick. The central bulge contains mostly older stars and globular clusters. Some recent evidence suggests the bulge might not be spherical, but is instead shaped like a bar. The bar might be as long as 27,000 light-years long. The disk and bulge are surrounded by a faint, spherical halo, which also contains old stars and globular clusters. Astronomers have discovered that there is a gigantic black hole at the center of the galaxy. The Milky Way Galaxy is a big place. If our solar system were the size of your fist, the Galaxys disk would still be An infrared image of the Milky Way shows the long thin line of stars and the central bulge typical of spiral galaxies. wider than the entire United States! "
in the center of the milky way galaxy is a,(A) Black hole (B) Neutron star (C) Supernova (D) Nebula,A,"The Milky Way Galaxy, which is our galaxy. The Milky Way is made of millions of stars along with a lot of gas and dust. It looks different from other galaxies because we are looking at the main disk from within the galaxy. Astronomers estimate that the Milky Way contains 200 to 400 billion stars. "
what is the evidence that the milky way is the type of galaxy that astronomers think it is?,(A) The shape as we see it (B) The rotational motion (C) The gases (D) color and amount of dust (E) d All of the above,D,"Although it is difficult to know what the shape of the Milky Way Galaxy is because we are inside of it, astronomers have identified it as a typical spiral galaxy containing about 200 billion to 400 billion stars (Figure 1.1). An artists rendition of what astronomers think the Milky Way Galaxy would look like seen from above. The Sun is located approximately where the arrow points. Like other spiral galaxies, our galaxy has a disk, a central bulge, and spiral arms. The disk is about 100,000 light- years across and 3,000 light-years thick. Most of the Galaxys gas, dust, young stars, and open clusters are in the disk. What evidence do astronomers find that lets them know that the Milky Way is a spiral galaxy? 1. The shape of the galaxy as we see it (Figure 1.2). 2. The velocities of stars and gas in the galaxy show a rotational motion. 3. The gases, color, and dust are typical of spiral galaxies. The central bulge is about 12,000 to 16,000 light-years wide and 6,000 to 10,000 light-years thick. The central bulge contains mostly older stars and globular clusters. Some recent evidence suggests the bulge might not be spherical, but is instead shaped like a bar. The bar might be as long as 27,000 light-years long. The disk and bulge are surrounded by a faint, spherical halo, which also contains old stars and globular clusters. Astronomers have discovered that there is a gigantic black hole at the center of the galaxy. The Milky Way Galaxy is a big place. If our solar system were the size of your fist, the Galaxys disk would still be An infrared image of the Milky Way shows the long thin line of stars and the central bulge typical of spiral galaxies. wider than the entire United States! "
one orbit of our solar system around the center of the galaxy takes about _______________.,(A) 225 to 500 years (B) 225 (C) 000 to 250 (D) 000 years (E) c 225 to 250 million years (F) d 250 to 275 billion years,C,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
the solar system formed 4.6 billion years ago.,(A) True (B) False,A,"Our solar system began about 5 billion years ago. The Sun, planets and other solar system objects all formed at about the same time. "
our solar system is,(A) Very near the center of the galaxy (B) About half way out one of the spiral arms of the galaxy (C) Just outside the galaxy (D) None of the above,B,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
"in our best spacecraft, how long would it take us to get to the center of the milky way galaxy?",(A) 26 (B) 000 years (C) b 26 (D) 000 light years (E) c 225 million years (F) d 225 million light years,B,"Our solar system, including the Sun, Earth, and all the other planets, is within one of the spiral arms in the disk of the Milky Way Galaxy. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are about 26,000 light-years from the center of the galaxy, a little more than halfway out from the center of the galaxy to the edge. Just as Earth orbits the Sun, the Sun and solar system orbit the center of the Galaxy. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. Astronomers have recently discovered that at the center of the Milky Way, and most other galaxies, is a supermassive black hole, although a black hole cannot be seen. This video describes the solar system in which we live. It is located in an outer edge of the Milky Way galaxy, which spans 100,000 light years. Click image to the left or use the URL below. URL:  The Universe contains many billions of stars and there are many billions of galaxies. Our home, the Milky Way galaxy, is only one. Click image to the left or use the URL below. URL: "
the milky way galaxy formed 4.6 billion years ago.,(A) True (B) False,B,"The Milky Way Galaxy, which is our galaxy. The Milky Way is made of millions of stars along with a lot of gas and dust. It looks different from other galaxies because we are looking at the main disk from within the galaxy. Astronomers estimate that the Milky Way contains 200 to 400 billion stars. "
the moons light is due to,(A) Nuclear fusion in its core (B) Reflected light from Earth (C) Reflected light from the Sun (D) None of the above,C,"Many other objects appear to produce their own light, but they actually just reflect light from another source. Being lit by another source is called illumination. The moon in the Figure 1.4 is glowing so brightly that you can see shadows under the trees. It appears to glow from its own light, but its really just illuminated by light from the sun. Everything you can see that doesnt produce its own light is illuminated by light from some other source. "
the moon orbits earth every 27.3 days and rotates on its axis once every 27.3 days. this means,(A) The same side of the Moon is always facing Earth (B) A lunar day is the same length of time as an Earth day (C) A lunar month is the same length of time as an Earth month (D) None of these,A,"Earth rotates on its axis once every 24 hours. This is the length of an Earth day. Earth orbits the Sun once every 365.24 days. This is the length of an Earth year. Earth has one large moon. This satellite orbits Earth once every 29.5 days. This moon is covered with craters, and also has large plains of lava. The Moon came into being from material that flew into space after Earth and a giant asteroid collided. This moon is not a captured asteroid like other moons in the solar system. "
the moon is earths only natural satellite.,(A) True (B) False,A,"The Moon is Earths only natural satellite, a body that moves around a larger body in space. The Moon orbits Earth for the same reason Earth orbits the Sun  gravity. The Moon is 3,476 km in diameter, about one-fourth the size of Earth. The satellite is also not as dense as the Earth; gravity on the Moon is only one-sixth as strong as it is on Earth. An astronaut can jump six times as high on the Moon as on Earth! The Moon makes one complete orbit around the Earth every 27.3 days. The Moon also rotates on its axis once every 27.3 days. Do you know what this means? The same side of the Moon always faces Earth, so that side of the Moon is what we always see in the night sky (Figure 1.1). The Moon makes no light of its own, but instead only reflects light from the Sun. (a) The near side of the Moon faces Earth continually. It has a thinner crust with many more maria (flat areas of basaltic rock). (b) The far side of the Moon has only been seen by spacecraft. It has a thicker crust and far fewer maria (flat areas of basaltic rock). "
many of the lunar craters are due to volcanic eruptions.,(A) True (B) False,B,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
the moon has extreme temperatures because it has no,(A) Gravity (B) Atmosphere (C) Night and day cycle (D) Weathering and erosion,B,"The Moon has no atmosphere. Since an atmosphere moderates temperature, the Moons average surface temperature during the day is approximately 225 F, but drops to -243 F at night. The coldest temperatures, around -397 F, occur in craters in the permanently shaded south polar basin. These are among the coldest temperatures recorded in the entire solar system. Earths landscape is extremely varied, with mountains, valleys, plains and hills. This landscape is always changing as plate tectonics builds new features and weathering and erosion destroys them. The landscape of the Moon is very different. With no plate tectonics, features are not built. With no atmosphere, features are not destroyed. Still, the Moon has a unique surface. Lunar surface features include the bowl-shaped craters that are caused by meteorite impacts (Figure 1.2). If Earth did not have plate tectonics or erosion, its surface would also be covered with meteorite craters. Even from Earth, the Moon has visible dark areas and light areas. The dark areas are called maria, which means seas because thats what the ancients thought they were. In fact, the maria are not water but solid, flat areas of basaltic lava. From about 3.0 to 3.5 billion years ago the Moon was continually bombarded by meteorites. Some of these meteorites were so large that they broke through the Moons newly formed surface. Then, magma flowed out and filled the craters. Scientists estimate this meteorite-caused volcanic activity on the Moon ceased about 1.2 billion years ago, but most occurred long before that. The lighter parts of the Moon are called terrae or highlands (Figure 1.3). The terrae are higher than the maria and A crater on the surface of the Moon. include several high mountain ranges. The terrae are the light silicate minerals that precipitated out of the ancient magma ocean and formed the early lunar crust. There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface, but water in the form of ice has been found in the extremely cold craters and bound up in the lunar soil. Despite the possible presence of water, the lack of an atmosphere and the extreme temperatures make it no surprise to scientists that the Moon has absolutely no evidence of life. Life from Earth has visited the Moon and there are footprints of astronauts on the lunar surface. With no wind, rain, or living thing to disturb them, these footprints will remain as long as the Moon exists. Only an impact with a meteorite could destroy them. "
the footprints of astronauts on the moon could,(A) Be erased by weathering and erosion (B) Be erased by plate tectonics (C) Be erased by a meteorite impact (D) Any of the above,C,"We all know what the Moon looks like. Its always looked the same during our lifetime. In fact, the Moon has looked the same to every person who has looked up at it for all time. Even the dinosaurs and trilobites, should they have looked up at it, would have seen the same thing. This is not true of Earth. Natural processes continually alter the Earths surface. Without these processes, would Earths surface resemble the Moons? Even though we cant see it from Earth, the Moon has changed recently too. Astronauts footprints are now on the Moon. They will remain unchanged for thousands of years, because there is no wind, rain, or living thing to disturb them. Only a falling meteorite could destroy them. "
the lunar maria are __________ that formed when __________.,(A) Felsic silicate rocks; silicate minerals precipitated out of the ancient magma ocean (B) Felsic silicate rocks; violent volcanic eruptions created the rock (C) Basalt; convection in the mantle caused volcanic eruptions (D) Basalt; meteorites caused volcanic eruptions,D,"When you look at the Moon from Earth, you notice dark and light areas. The maria are dark, solid, flat areas of lava. Maria covers around 16% of the Moons surface, mostly on the near side. The maria formed about 3.0 to 3.5 billion years ago, when the Moon was continually bombarded by meteorites (Figure 24.15). Large meteorites broke through the Moons newly formed surface. This caused magma to flow out and fill the craters. Scientists estimate volcanic activity on the Moon ended about 1.2 billion years ago. The lighter parts on the Moon are called terrae, or highlands (Figure 24.15). They are higher than the maria and include several high mountain ranges. The rock that makes up the highlands is lighter in color and crystallized more slowly than the maria. The rock looks light because it reflects more of the Suns light. "
the moons interior the same as earths interior; the same rock and metal make up the mantle and core in the same proportions.,(A) True (B) False,B,"Like Earth, the Moon has a distinct crust, mantle, and core. The crust is composed of igneous rock. This rock is rich in the elements oxygen, silicon, magnesium, and aluminum. On the near side, the Moons crust is about 60 kilometers thick. On the far side, the crust is about 100 kilometers thick. The mantle is made of rock like Earths mantle. The Moon has a small metallic core, perhaps 600 to 800 kilometers in diameter. The composition of the core is probably mostly iron with some sulfur and nickel. We learned this both from the rock samples gathered by astronauts and from spacecraft sent to the Moon. "
which of the following is true about the moons interior?,(A) The core is large relative to Earth’s core (B) The composition of the Moon’s mantle and core are very different from Earth’s (C) The Moon’s mantle and core are made of mafic rock and metal (D) respectively (E) d All of the above,C,"Like Earth, the Moon has a distinct crust, mantle, and core. What is known about the Moons interior was determined from the analysis of rock samples gathered by astronauts and from unmanned spacecraft sent to the Moon (Figure The Moons small core, 600 to 800 kilometers in diameter, is mostly iron with some sulfur and nickel. The mantle is composed of the minerals olivine and orthopyroxene. Analysis of Moon rocks indicates that there may also be high levels of iron and titanium in the lunar mantle. A close-up of the Moon, showing maria (the dark areas) and terrae (the light areas); maria covers around 16% of the Moons surface, mostly on the side of the Moon we see. LCROSS crashed into the Moon in May 2009. This QUEST video describes the mission. After watching, look up the mission to see what they found! Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
which of the following is true about the moons crust?,(A) It is a lot thicker on the far side than on the near side (B) It is composed of the minerals olivine and orthopyroxene (C) It is all the same age (D) All of these,A,"Like Earth, the Moon has a distinct crust, mantle, and core. The crust is composed of igneous rock. This rock is rich in the elements oxygen, silicon, magnesium, and aluminum. On the near side, the Moons crust is about 60 kilometers thick. On the far side, the crust is about 100 kilometers thick. The mantle is made of rock like Earths mantle. The Moon has a small metallic core, perhaps 600 to 800 kilometers in diameter. The composition of the core is probably mostly iron with some sulfur and nickel. We learned this both from the rock samples gathered by astronauts and from spacecraft sent to the Moon. "
natural gas is mostly composed of hydrocarbon ____________.,(A) propane (B) methane (C) butane (D) benzene,B,Natural gas is mostly methane. 
fracking has increased rapidly in the united states in recent years.,(A) True (B) False,A,"Natural gas burns much cleaner than other fossil fuels, meaning that it causes less air pollution. Natural gas also produces less carbon dioxide than other fossil fuels do for the same amount of energy, so its global warming effects are less (Figure 1.2). Unfortunately, drilling for natural gas can be environmentally destructive. One technique used is hydraulic fractur- ing, also called fracking, which increases the rate of recovery of natural gas. Fluids are pumped through a borehole to create fractures in the reservoir rock that contains the natural gas. Material is added to the fluid to prevent the fractures from closing. The damage comes primarily from chemicals in the fracturing fluids. Chemicals that have been found in the fluids may be carcinogens (cancer-causing), radioactive materials, or endocrine disruptors, which interrupt hormones in the bodies of humans and animals. The fluids may get into groundwater or may runoff into streams and other surface waters. As noted above, fracking may cause earthquakes. Click image to the left or use the URL below. URL: "
plant materials that are buried beneath so much sediment that they are altered by heat and pressure over millions of years can become ____________.,(A) Petroleum (B) Natural gas (C) Coal (D) All of the above,D,"When ancient plants underwent photosynthesis, they changed energy in sunlight to stored chemical energy in food. The plants used the food and so did the organisms that ate the plants. After the plants and other organisms died, their remains gradually changed to fossil fuels as they were covered and compressed by layers of sediments. Petroleum and natural gas formed from ocean organisms and are found together. Coal formed from giant tree ferns and other swamp plants. "
from what source is natural gas extracted?,(A) Shale (B) Soil (C) Granite (D) Basalt,A,"Natural gas forms under the same conditions that create oil. Organic material buried in the sediments harden to become a shale formation that is the source of the gas. Although natural gas forms at higher temperatures than crude oil, the two are often found together. The largest natural gas reserves in the United States are in the Appalachian Basin, North Dakota and Montana, Texas, and the Gulf of Mexico region (Figure 1.1). California also has natural gas, found mostly in the Central Valley. In the northern Sacramento Valley and the Sacramento Delta, a sediment-filled trough formed along a location where crust was pushed together (an ancient convergent margin). Gas production in the lower 48 United States. "
"natural gas often forms with crude oil, but at a lower temperature.",(A) True (B) False,B,Natural gas is often found along with coal or oil in underground deposits. This is because natural gas forms with these other fossil fuels. One difference between natural gas and oil is that natural gas forms at higher temperatures. 
where in the united states are the large gas deposits?,(A) Surrounding the Rocky Mountains (B) The Appalachian Basin (C) Gulf of Mexico region (D) All of the above,D,"The largest natural gas reserves in the United States are located in the Rocky Mountain states, Texas, and the Gulf of Mexico region. California also has natural gas, mostly in the northern Sacramento Valley and the Sacramento Delta. Natural gas must be processed before it can be used as a fuel. Poisonous chemicals and water must be removed. Natural gas is delivered to homes, where it is used for cooking and heating. Natural gas is also a major energy source for powering turbines to make electricity. Natural gas releases most of its energy as heat when it burns. The power plant is able to use this heat, either in the form of hot gases or steam, to spin turbines. The spinning turbines turn generators, and the generators create electricity. "
before natural gas can be used it must,(A) Be converted to gaseous form (B) Be diluted with water (C) Have toxic chemicals removed (D) All of the above,C,"Like crude oil, natural gas must be processed before it can be used as a fuel. Some of the chemicals in unprocessed natural gas are poisonous to humans. Other chemicals, such as water, make the gas less useful as a fuel. Processing natural gas removes almost everything except the methane. Once the gas is processed, it is ready to be delivered and used. Natural gas is delivered to homes for uses such as cooking and heating. Like coal and oil, natural gas is also burned to generate heat for powering turbines. The spinning turbines turn generators, and the generators create electricity. Click image to the left or use the URL below. URL: "
earthquake activity has increased in locations where there is a fracking boom.,(A) True (B) False,A,"In August 2011 the eastern seaboard of the U.S. was rocked by a magnitude 5.8 earthquake. While not huge, most of the residents had never experienced a quake and many didnt know what it was. Some people thought the shaking might have been the result of a terrorist attack. This region is no longer part of an active plate boundary. But if you went back in time to the late Paleozoic, you would find the region being uplifted into the ancestral Appalachian mountains as continent-continent convergence brought Pangaea together. The Piedmont Seismic Zone is an area of several hundred million year-old faults that sometimes reactivate. "
fossil fuels burn much cleaner than natural gas.,(A) True (B) False,A,"Processing natural gas has harmful effects on the environment, just like oil. Natural gas burns cleaner than other fossil fuels. As a result, it causes less air pollution. It also produces less carbon dioxide than the other fossil fuels. Still, natural gas does emit pollutants. "
why should you use renewable resources rather than nonrenewable resources?,(A) Renewable resources have a greater supply than we can use (B) Renewable resources are less expensive (C) Renewable resources are always cleaner to use (D) All of these,A,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
it is better to drink from a tap than a plastic water bottle because,(A) Tap water tastes better (B) The plastic bottle will be trash for a very long time (C) Tap water is more nutritious (D) All of these,B,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
what is the best way to reduce your consumption?,(A) Recycle more (B) Buy less stuff (C) Buy only products that do not emit pollution (D) Buy only products made from recycled material,B,"Reducing the amount of natural resources you use is the best way to conserve resources. It takes energy to make new items, and even reusing or recycling items takes energy. You can reduce the amount of natural resources you use by not using the resources in the first place. Often, this involves just being less wasteful. Follow these tips to reduce your use of natural resources: Walk, bike, or use public transit instead of driving. If you must drive, a fuel-efficient vehicle will reduce energy use. Plan ahead to avoid making extra trips. Dont buy more than you need. For example, dont buy more fresh food than you can use without it going to waste. You will not only reduce your use of food. You will also reduce your use of energy resources. It takes a lot of energy to grow, process, and ship many of the foods we buy. When you shop, keep packaging in mind. ""Precycle"" by buying items with the least amount of wasted packaging. Use energy-efficient appliances and LED light bulbs. Also, turn off appliances and lights when you arent using them. Both steps will reduce the amount of energy resources you use. Keep the thermostat set low in the winter and high in the summer (see Figure 25.12). Instead of turning up the heat in cold weather, put on an extra layer of clothes to save energy resources. Open windows and use fans in hot weather rather than turning on the air conditioning. "
"if we all recycle, there will be enough resources for people in developing nations to have the same lifestyle as people in developed nations.",(A) True (B) False,B,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
soil is a resource that must be protected.,(A) True (B) False,A,Soil is only a renewable resource if it is carefully managed. There are many practices that can protect and preserve soil resources. 
individuals cant really make a difference in natural resource use.,(A) True (B) False,B,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
"trees a renewable resource, but forests are much less renewable.",(A) True (B) False,A,"From a human point of view, natural resources can be classified as either renewable or nonrenewable. "
how does driving less reduce resource use?,(A) It uses less gas (B) It puts less pollution into the air (C) It lessens use of metals and other materials by putting less wear on the car (D) All of the above,D,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
which one of these can you not recycle,(A) Aluminum cans (B) Cell phones (C) Plastic bottles (D) Trees,D,"If an item can no longer be used or reused, try to recycle it. Recycling means taking a used item, breaking it down, and reusing the components. It generally takes less energy to recycle materials than obtain new ones. Recycling also keeps waste out of landfills. Some of the items that can be recycled include: glass, paper, cardboard, plastic, aluminum, iron, steel, batteries, electronics, tires, and concrete. You can learn how some of these materials are recycled by watching this video:  . MEDIA Click image to the left or use the URL below. URL:  Even kitchen scraps and garden wastes can be recycled. They can be tossed into a compost bin, like the one in Figure 25.13. The recycled compost gradually breaks down to form rich humus that can be added to lawns and gardens to improve the soil. Encourage your family to recycle if they dont already. Even if you dont have curbside recycling where you live, there are likely to be recycling drop boxes or centers available for recycling many items. If you have recycling bins at school, be sure to use them. If not, raise the issue with your teacher or principal. You can also write a letter to the editor of your local newspaper encouraging everyone in your community to recycle. "
"when you go to the store and the clerk asks, paper or plastic?, which bag should you take?",(A) Paper: Paper degrades and is made from trees (B) which are renewable (C) b Plastic: Plastic is stronger so you need fewer bags over time (D) c Neither: Bring your own bag; that’s the best choice for the environment (E) d Both: A paper bag in a plastic bag is very strong,C,"Reusing means to use an item again rather than throwing it away and replacing it. Items can be reused for the same purpose or for a different purpose. Generally, it takes less energy to reuse an item than to recycle it, so choose this option over recycling when you can. Here are some specific tips for reusing natural resources: Consider mending or repairing worn or broken items rather than throwing them out and replacing them. Shop with reuse in mind. You can find great buys at flea markets and resale shops. You may be able to get free items online at free-cycle sites. Youll save money as well as natural resources. You can also sell (or give away) your own reusable items. Reuse cloth shopping bags. Instead of getting new plastic or paper bags for your purchases each time you shop, take your own reusable bag to the store each time. Even little steps can add up and help save natural resources. For example, unwrap gifts carefully and youll be able to reuse the gift wrap on a package for someone else. You can also reuse writing paper that has only been used on one side. Its great for notes and shopping lists. "
which is not a characteristic of neptune?,(A) It is 28 billion miles from the Sun (B) One orbit around the Sun takes Neptune 165 Earth years (C) It has a calm atmosphere (D) It is the 8th planet from the Sun,C,"Like Uranus, Neptune is blue. The blue color is caused by gases in its atmosphere, including methane. Neptune is not a smooth looking ball like Uranus. The planet has a few darker and lighter spots. When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot south of the equator. This spot was called the Great Dark Spot. When the Hubble Space Telescope photographed Neptune in 1994, the Great Dark Spot had disappeared. Another dark spot had appeared north of the equator. Astronomers believe that both of these spots represent gaps in the methane clouds on Neptune. Neptunes appearance changes due to its turbulent atmosphere. Winds are stronger than on any other planet in the solar system. Wind speeds can reach 1,100 km/h (700 mph). This is close to the speed of sound! The rapid winds surprised astronomers. This is because Neptune receives little energy from the Sun to power weather systems. It is not surprising that Neptune is one of the coldest places in the solar system. Temperatures at the top of the clouds are about 218C (360F). "
what led scientists to predict the existence of neptune before it was seen?,(A) Ancient shepherds had a myth of an 4th outer planet (B) Meteorites on Earth came from a planet that wasn’t any of the known ones (C) Uranus orbit appeared to be affected by the gravitational pull of another planet (D) None of the above,C,"Neptune, shown in Figure 1.1, is the only major planet that cant be seen from Earth without a telescope. Scientists predicted the existence of Neptune before it was discovered because Uranus did not always appear exactly where it should appear. They knew that the gravitational pull of another planet beyond Uranus must be affecting Uranus orbit. Neptune was discovered in 1846, in the position that had been predicted, and it was named Neptune for the Roman god of the sea because of its bluish color. This image of Neptune was taken by Voy- ager 2 in 1989. The Great Dark Spot seen on the left center in the picture has since disappeared, but a similar dark spot has appeared on another part of the planet. In many respects, Neptune is similar to Uranus (Figure 1.2). Neptune has slightly more mass than Uranus, but it is slightly smaller in size. Neptune is much farther from the Sun, at nearly 4.5 billion km (2.8 billion mi). The planets slow orbit means that it takes 165 Earth years to go once around the Sun. "
neptunes appearance,(A) Changes because it has a turbulent atmosphere (B) Changes because the gas composition is continually changing (C) Doesn’t change because its atmosphere is stable (D) Doesn’t change because its gas composition is stable,A,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
what causes neptune to be blue in color?,(A) A planet-wide blue ocean (B) Frozen water (C) Frozen methane (D) No one knows,C,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
dark spots on neptune are storms that come and go.,(A) True (B) False,B,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
the great dark spot,(A) Has been around as long as we’ve been able to observe Neptune (B) Disappeared (C) Is a storm that has been going on for centuries (D) Sticks out since it is a reddish color on a blue planet,B,"The upper layer of Jupiters atmosphere contains clouds of ammonia (NH3 ) in bands of different colors. These bands rotate around the planet, but also swirl around in turbulent storms. The Great Red Spot (Figure 1.3) is an enormous, oval-shaped storm found south of Jupiters equator. This storm is more than three times as wide as the entire Earth. Clouds in the storm rotate in a counterclockwise direction, making one complete turn every six days or so. The Great Red Spot has been on Jupiter for at least 300 years, since astronomers could first see the storm through telescopes. Do you think the Great Red Spot is a permanent feature on Jupiter? How could you know? This image of Jupiters Great Red Spot (upper right of image) was taken by the Voyager 1 spacecraft. The white storm just below the Great Red Spot is about the same diameter as Earth. "
where does neptune get its energy?,(A) From it’s extremely hot core (B) From Uranus (C) From sources outside the solar system (D) From the Sun,A,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
"neptunes moon, triton,",(A) Orbits in the opposite direction from Neptune (B) Is the only of Neptune’s moon’s to be spherical (C) Was probably captured by Neptune’s gravity (D) All of the above,D,"Neptune has faint rings of ice and dust that may change or disappear in fairly short time frames. Neptune has 13 known moons. Triton, shown in Figure 1.3, is the only one of them that has enough mass to be spherical in shape. Triton orbits in the direction opposite to the orbit of Neptune. Scientists think Triton did not form around Neptune, but instead was captured by Neptunes gravity as it passed by. This image of Triton, Neptunes largest moon, was taken by Voyager 2 in 1989. "
neptune produces more energy than it receives from the sun.,(A) True (B) False,A,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
"neptunes mantle is made of water, ammonia, and methane ice.",(A) True (B) False,A,"Neptunes blue color is mostly because of frozen methane (CH4 ). When Voyager 2 visited Neptune in 1986, there was a large dark-blue spot, which scientists named the Great Dark Spot, south of the equator. When the Hubble Space Telescope took pictures of Neptune in 1994, the Great Dark Spot had disappeared, but another dark spot had appeared north of the equator. Astronomers think that both of these spots represent gaps in the methane clouds on Neptune. The changing appearance of Neptune is caused by its turbulent atmosphere. The winds on Neptune are stronger than on any other planet in the solar system, reaching speeds of 1,100 km/h (700 mi/h), close to the speed of sound. This extreme weather surprised astronomers, since the planet receives little energy from the Sun to power weather systems. Neptunes core is 7000 C (12,632 C) which means that it produces more energy than it receives from the Sun. Neptune is also one of the coldest places in the solar system. Temperatures at the top of the clouds are about -218 C (-360 F). Neptunes composition is that of a gas giant: (1) upper atmosphere, (2) atmo- sphere composed of hydrogen, helium and methane gas, (3) mantle of water, ammonia and methane ice, (4) core of rock and ice. "
which of the following have bacteria in their root nodules that fix nitrogen?,(A) Legumes (B) Meat (C) Trees (D) Algae,A,"Animals eat plant tissue and create animal tissue. After a plant or animal dies or an animal excretes waste, bacteria and some fungi in the soil fix the organic nitrogen and return it to the soil as ammonia. Nitrifying bacteria oxidize the ammonia to nitrites, while other bacteria oxidize the nitrites to nitrates, which can be used by the next generation of plants. In this way, nitrogen does not need to return to a gas. Under conditions when there is no oxygen, some bacteria can reduce nitrates to molecular nitrogen. Click image to the left or use the URL below. URL: "
nitrogen gas found in the atmosphere is useful to organisms.,(A) True (B) False,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
living things need nitrogen for,(A) Amino acids (B) Nucleic acids (C) Photosynthesis (D) All of these,D,"Living things also need nitrogen. Nitrogen is a key element in proteins. Like carbon, nitrogen cycles through ecosystems. You can see the nitrogen cycle in Figure 18.13. "
nitrogen is only useful to animals and humans in which form,(A) Plant (B) Lightning (C) Gas (D) None of the above,D,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
nitrogen fixing bacteria convert nitrogen to,(A) Nitrogen oxide (B) Ammonium (C) Water (D) Plants,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
nitrogen can be recycled in plants and soil and does not need to return to the atmosphere as a gas.,(A) True (B) False,A,"Like water and carbon, nitrogen is also repeatedly recycled through the biosphere. This process is called the nitrogen cycle. Nitrogen is one of the most common elements in living organisms. It is important for creating both proteins and nucleic acids, like DNA. The air that we breathe is mostly nitrogen gas (N2 ), but, unfortunately, animals and plants cannot use the nitrogen when it is a gas. In fact, plants often die from a lack of nitrogen even through they are surrounded by plenty of nitrogen gas. Nitrogen gas (N2 ) has two nitrogen atoms connected by a very strong triple bond. Most plants and animals cannot use the nitrogen in nitrogen gas because they cannot break that triple bond. In order for plants to make use of nitrogen, it must be transformed into molecules they can use. This can be accomplished several different ways ( Figure 1.1). Lightning: When lightening strikes, nitrogen gas is transformed into nitrate (NO3  ) that plants can use. Nitrogen fixation: Special nitrogen-fixing bacteria can also transform nitrogen gas into useful forms. These bacteria live in the roots of plants in the pea family. They turn the nitrogen gas into ammonium (NH4 + ) (a process called ammonification). In water environments, bacteria in the water can also fix nitrogen gas into ammonium. Ammonium can be used by aquatic plants as a source of nitrogen. Nitrogen also is released to the environment by decaying organisms or decaying wastes. These wastes release nitrogen in the form of ammonium. Ammonium in the soil can be turned into nitrate by a two-step process completed by two different types of bacteria. In the form of nitrate, nitrogen can be used by plants through the process of assimilation. It is then passed along to animals when they eat the plants. "
nitrifying bacteria convert,(A) Nitrogen oxide to nitrogen gas (B) Nitrogen to nitrates (C) Ammonium to nitrites (D) Water to nitrogen gas,C,"Animals eat plant tissue and create animal tissue. After a plant or animal dies or an animal excretes waste, bacteria and some fungi in the soil fix the organic nitrogen and return it to the soil as ammonia. Nitrifying bacteria oxidize the ammonia to nitrites, while other bacteria oxidize the nitrites to nitrates, which can be used by the next generation of plants. In this way, nitrogen does not need to return to a gas. Under conditions when there is no oxygen, some bacteria can reduce nitrates to molecular nitrogen. Click image to the left or use the URL below. URL: "
leguminous plants,(A) Include peas (B) beans and peanuts (C) b Use ammonia produced by nitrogen-fixing bacteria (D) c Supply carbohydrates to nitrogen-fixing bacteria (E) d All of these,D,"Seedless plants have been tremendously useful to humans. Without these plants evolving millions of years ago, life as we know it would be very different. "
nitrogen from animal wastes or plant and animal tissue,(A) Must be fixed near leguminous plants (B) Is lost from the system (C) Is fixed by bacteria and fungi in the soil (D) Is already fixed and can be used,C,"Like water and carbon, nitrogen is also repeatedly recycled through the biosphere. This process is called the nitrogen cycle. Nitrogen is one of the most common elements in living organisms. It is important for creating both proteins and nucleic acids, like DNA. The air that we breathe is mostly nitrogen gas (N2 ), but, unfortunately, animals and plants cannot use the nitrogen when it is a gas. In fact, plants often die from a lack of nitrogen even through they are surrounded by plenty of nitrogen gas. Nitrogen gas (N2 ) has two nitrogen atoms connected by a very strong triple bond. Most plants and animals cannot use the nitrogen in nitrogen gas because they cannot break that triple bond. In order for plants to make use of nitrogen, it must be transformed into molecules they can use. This can be accomplished several different ways ( Figure 1.1). Lightning: When lightening strikes, nitrogen gas is transformed into nitrate (NO3  ) that plants can use. Nitrogen fixation: Special nitrogen-fixing bacteria can also transform nitrogen gas into useful forms. These bacteria live in the roots of plants in the pea family. They turn the nitrogen gas into ammonium (NH4 + ) (a process called ammonification). In water environments, bacteria in the water can also fix nitrogen gas into ammonium. Ammonium can be used by aquatic plants as a source of nitrogen. Nitrogen also is released to the environment by decaying organisms or decaying wastes. These wastes release nitrogen in the form of ammonium. Ammonium in the soil can be turned into nitrate by a two-step process completed by two different types of bacteria. In the form of nitrate, nitrogen can be used by plants through the process of assimilation. It is then passed along to animals when they eat the plants. "
"modern fertilizers supply fixed nitrogen to the soil, eliminating the need for nitrogen-fixing bacteria.",(A) True (B) False,A,"Animals eat plant tissue and create animal tissue. After a plant or animal dies or an animal excretes waste, bacteria and some fungi in the soil fix the organic nitrogen and return it to the soil as ammonia. Nitrifying bacteria oxidize the ammonia to nitrites, while other bacteria oxidize the nitrites to nitrates, which can be used by the next generation of plants. In this way, nitrogen does not need to return to a gas. Under conditions when there is no oxygen, some bacteria can reduce nitrates to molecular nitrogen. Click image to the left or use the URL below. URL: "
all of the following are renewable energy resources except,(A) solar energy (B) wind energy (C) nuclear energy (D) biomass energy,C,"Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table 17.1. Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. here? Renewable Energy Resource Sunlight The energy in sunlight, or solar energy, can be used to heat homes. It can also be used to produce electricity in solar cells. However, solar energy may not be practical in areas that are often cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water When water falls downhill, its potential energy is con- verted to kinetic energy that can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream and reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air, so it has kinetic energy that can do work. Remember the wind turbines that opened this chapter? Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy and unattractive in the landscape. Water flowing through Hoover dam between Arizona and Nevada generates electricity for both of these states and also by southern California. The dam spans the Colorado River. This old-fashioned windmill captures wind energy that is used for pumping water out of a well. Windmills like this one have been used for centuries. Renewable Energy Resource Biomass The stored chemical energy of trees and other plants is called biomass energy. When plant materials are burned, they produce thermal energy that can be used for heating, cooking, or generating electricity. Biomassespecially woodis an important energy source in countries where most people cant afford fossil fuels. Some plants can also be used to make ethanol, a fuel that is added to gasoline. Ethanol produces less pollution than gasoline, but large areas of land are needed to grow the plants needed to make it. Geothermal Heat below Earths surfacecalled geothermal en- ergycan be used to produce electricity. A power plant pumps water underground where it is heated. Then it pumps the water back to the plant and uses its thermal energy to generate electricity. On a small scale, geothermal energy can be used to heat homes. Installing a geothermal system can be very costly, how- ever, because of the need to drill through underground rocks. Example This large machine is harvesting and grinding plants to be used for biomass energy. This geothermal power plant is located in Italy where hot magma is close to the surface. "
most renewable resources produce little if any pollution.,(A) true (B) false,A,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
renewable energy resources are used more commonly than nonrenewable energy resources.,(A) true (B) false,B,"Look at the circle graph in the Figure 1.1. It shows that oil is the single most commonly used energy resource in the U.S., followed by natural gas, and then by coal. All of these energy resources are nonrenewable. Nonrenewable resources are resources that are limited in supply and cannot be replaced as quickly as they are used up. Renewable resources, in contrast, provide only 8 percent of all energy used in the U.S. Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. They include solar energy from sunlight, geothermal energy from under Earths surface, wind, biomass (from once-living things or their wastes), and hydropower (from running water). "
which energy resource is used to produce hydroelectric power?,(A) sun (B) wind (C) water (D) biomass,C,"Moving water has energy (Figure 5.10). That energy is used to make electricity. Hydroelectric power harnesses the energy of water moving down a stream. Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the worlds electricity. The energy of waves and tides can also be used to produce water power. At this time, wave and tidal power are rare. "
which energy resource is used to produce fuel for cars?,(A) geothermal energy (B) biomass energy (C) solar energy (D) none of the above,B,"The energy to make the electricity comes from fuel. Fuel stores the energy and releases it when it is needed. Fuel is any material that can release energy in a chemical change. The food you eat acts as a fuel for your body. Gasoline and diesel fuel are fuels that provide the energy for most cars, trucks, and buses. But there are many different kinds of fuel. For fuel to be useful, its energy must be released in a way that can be controlled. "
people have been using wind and water for energy only for the past century.,(A) true (B) false,B,"Wind is the source of energy for wind power. Wind has been used for power for centuries. For example, windmills were used to grind grain and pump water. Sailing ships traveled by wind power long before ships were powered by fossil fuels. Wind can be used to generate electricity, as the moving air spins a turbine to create electricity (Figure Click image to the left or use the URL below. URL: "
nuclear energy as it is currently used in nuclear power plants is the result of,(A) Fusing protons and neutrons together (B) Stripping electrons from atomic nuclei (C) Fusing hydrogen into helium (D) Splitting atomic nuclei,D,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
"which element is mined, processed, and concentrated into fuel rods to be used at nuclear power plants?",(A) Helium (B) Potassium (C) Uranium (D) Thorium,C,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
the number of tiny particles allowed to hit the uranium fuel rods must be unpredictable and spontaneous.,(A) True (B) False,B,"Nuclear power plants use uranium that has been concentrated in fuel rods (Figure 5.6). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion. Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. "
nuclear energy is a source of electricity.,(A) True (B) False,A,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
uranium mining is an important part of generating nuclear power.,(A) True (B) False,A,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
the only major accident so far at a nuclear power plant was caused by an enormous earthquake and tsunami in japan.,(A) True (B) False,B,"The Japanese received a one-two punch in March 2011. The 2011 Tohoku earthquake offshore was a magnitude 9.0 and damage from the quake was extensive. People didnt have time to recover before massive tsunami waves hit the island nation. As seen in Figure 1.2, waves in some regions topped 9 meters (27 feet). The tsunami did much more damage than the massive earthquake (Figure 1.3). Worst was the damage done to nuclear power plants along the northeastern coast. Eleven reactors were automatically shut down. Power and backup power were lost at the Fukushima plant, leading to equipment failures, meltdowns, and the release of radioactive materials. Control and cleanup of the disabled plants will go on for many years. "
"the energy in a nuclear power plant creates ______, which causes a turbine to spin.",(A) Electricity (B) Water (C) Radiation (D) Steam,D,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
which is an environmental benefit of nuclear power?,(A) Nuclear power does not produce greenhouse gases (B) The radioactive waste created from the nuclear power process is used to power cars (C) Advanced technology has eliminated the possibility of explosions (D) All of the above,A,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution that harms the health of living things. The air pollution also causes acid rain and contributes to global warming. In addition, fossil fuels are nonrenewable resources, so if we keep using them, they will eventually run out. The main advantage of nuclear energy is that it doesnt release air pollution or cause the other environmental problems associated with the burning of fossil fuels. On the other other hand, radioactive elements are nonrenewable like fossil fuels and could eventually be used up. The main concern over the use of nuclear energy is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to protect people and other living things. Click image to the left or use the URL below. URL: "
negative environmental consequences of nuclear power include,(A) Air pollution (B) including carbon emissions (C) b Waste that is radioactive for hundreds of thousands of years (D) c Ozone depletion (E) d All of the above,B,"Nuclear power is clean. It does not pollute the air. However, the use of nuclear energy does create other environ- mental problems. Uranium must be mined (Figure 1.3). The process of splitting atoms creates radioactive waste, which remains dangerous for thousands or hundreds of thousands of years. As yet, there is no long-term solution for storing this waste. The development of nuclear power plants has been on hold for three decades. Accidents at Three Mile Island and Chernobyl, Ukraine verified peoples worst fears about the dangers of harnessing nuclear power (Figure 1.4). Recently, nuclear power appeared to be making a comeback as society looked for alternatives to fossil fuels. After all, nuclear power emits no pollutants, including no greenhouse gases. But the 2011 disaster at the Fukushima Daiichi Nuclear Power Plant in Japan may have resulted in a new fear of nuclear power. The cause of the disaster was a 9.0 magnitude earthquake and subsequent tsunami, which compromised the plant. Although a total meltdown was averted, the plant experienced multiple partial meltdowns, core breaches, radiation releases, and cooling failures. The plant is scheduled for a complete cold shutdown before the end of 2011. Damaged building near the site of the Chernobyl disaster. Nuclear power is a controversial subject in California and most other places. Nuclear power has no pollutants including carbon emissions, but power plants are not always safe and the long-term disposal of wastes is a problem that has not yet been solved. The future of nuclear power is murky. "
"to generate power, uranium atoms in fuel rods",(A) Are hit by tiny particles so that they split apart (B) Are safe as long as the uranium stays in the rods (C) Fuses into lead (D) which releases energy (E) d All of the above,A,"Nuclear power plants use uranium that has been concentrated in fuel rods (Figure 5.6). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion. Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. "
incandescent light bulbs are more efficient than compact fluorescent light bulbs.,(A) True (B) False,B,A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure 1.2 contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. 
what is the amount of useable energy available from a resource after subtracting the amount of energy needed to make that energy available?,(A) Zero energy (B) Net energy (C) Reduced energy (D) None of the above,B,"Net energy is the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available. For example, every 5 barrels of oil that are made available for use require 1 barrel for extracting and refining the petroleum. What is the net energy from this process? About 4 barrels (5 barrels minus 1 barrel). What happens if the energy needed to extract and refine oil increases? Why might that happen? The energy cost of an energy resource increases when the easy deposits of that resource have already been consumed. For example, if all the nearshore petroleum in a region has been extracted, more costly drilling must take place further offshore (Figure 1.1). If the energy cost of obtaining energy increases, the resource will be used even faster. Offshore drilling is taking place in deeper water than before. It takes a lot of energy to build a deep drilling platform and to run it. "
if every 100 barrels of oil that are made available for use require 20 barrels for extracting and refining the petroleum. what is the net energy from this process?,(A) 80 barrels (B) 100 barrels (C) 20 barrels (D) 120 barrels,A,"Net energy is the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available. For example, every 5 barrels of oil that are made available for use require 1 barrel for extracting and refining the petroleum. What is the net energy from this process? About 4 barrels (5 barrels minus 1 barrel). What happens if the energy needed to extract and refine oil increases? Why might that happen? The energy cost of an energy resource increases when the easy deposits of that resource have already been consumed. For example, if all the nearshore petroleum in a region has been extracted, more costly drilling must take place further offshore (Figure 1.1). If the energy cost of obtaining energy increases, the resource will be used even faster. Offshore drilling is taking place in deeper water than before. It takes a lot of energy to build a deep drilling platform and to run it. "
the net energy obtained from a resource decreases when the easy deposits of that resource have been consumed.,(A) True (B) False,A,"Net energy is the amount of useable energy available from a resource after subtracting the amount of energy needed to make the energy from that resource available. For example, every 5 barrels of oil that are made available for use require 1 barrel for extracting and refining the petroleum. What is the net energy from this process? About 4 barrels (5 barrels minus 1 barrel). What happens if the energy needed to extract and refine oil increases? Why might that happen? The energy cost of an energy resource increases when the easy deposits of that resource have already been consumed. For example, if all the nearshore petroleum in a region has been extracted, more costly drilling must take place further offshore (Figure 1.1). If the energy cost of obtaining energy increases, the resource will be used even faster. Offshore drilling is taking place in deeper water than before. It takes a lot of energy to build a deep drilling platform and to run it. "
drilling for oil far offshore is now taking place because,(A) The easier to obtain nearshore deposits have been extracted (B) Technology has advanced so that drilling far offshore is now possible (C) The cost of oil is high enough to make extraction in these locations cost effective (D) All of these,D,"New drilling techniques have allowed oil companies to drill in deeper waters than ever before. This allows us to access oil deposits that were never before accessible, but only with great technological difficulty. The risks from deepwater drilling and the consequences when something goes wrong are greater than those associated with shallower wells. "
the net-energy ratio is the amount of energy in a resource with the amount of energy needed to obtain it subtracted.,(A) True (B) False,A,"The net-energy ratio demonstrates the difference between the amount of energy available in a resource and the amount of energy used to get it. If it takes 8 units of energy to make available 10 units of energy, then the net-energy ratio is 10/8 or 1.25. What does a net-energy ratio larger than 1 mean? What if the net-energy ratio is less than 1? A net-energy ratio larger than 1 means that there is a net gain in usable energy; a net-energy ratio smaller than one means there is an overall energy loss. Table 1.1 shows the net-energy ratios for some common energy sources. Energy Source Solar Energy Natural Gas Petroleum Coal-fired Electricity Net-energy Ratio 5.8 4.9 4.5 2.5-5.1 Notice from the table that solar energy yields much more net energy than other sources. This is because it takes very little energy to get usable solar energy. Sunshine is abundant and does not need to be found, extracted, or transported very far. The range for coal-fired electricity is because of the differing costs of transporting the coal. What does this suggest about using coal to generate electricity? The efficiency is greater in areas where the coal is locally mined and does not have to be transported great distances (Figure 1.2). Obtaining coal for energy takes a lot of energy. The coal must be located, extracted, refined, and transported. Because so much of the energy we use is from fossil fuels, we need to be especially concerned about using them efficiently. Sometimes our choices affect energy efficiency. For example, transportation by cars and airplanes is less energy-efficient than transportation by boats and trains. "
why does solar energy have a higher net energy yield than petroleum?,(A) Solar energy is less expensive (B) It takes relatively smaller amount of energy to get usable petroleum (C) Sunlight is abundant and is everywhere (D) All of these,C,"Solar energy has been used for power on a small scale for hundreds of years, and plants have used it for billions of years. Unlike energy from fossil fuels, which almost always come from a central power plant or refinery, solar power can be harnessed locally (Figure 1.1). A set of solar panels on a homes rooftop can be used to heat water for a swimming pool or can provide electricity to the house. Societys use of solar power on a larger scale is just starting to increase. Scientists and engineers have very active, ongoing research into new ways to harness energy from the Sun more efficiently. Because of the tremendous amount of incoming sunlight, solar power is being developed in the United States in southeastern California, Nevada, and Arizona. Solar panels supply power to the Interna- tional Space Station. Solar power plants turn sunlight into electricity using a large group of mirrors to focus sunlight on one place, called a receiver (Figure 1.2). A liquid, such as oil or water, flows through this receiver and is heated to a high temperature by the focused sunlight. The heated liquid transfers its heat to a nearby object that is at a lower temperature through a process called conduction. The energy conducted by the heated liquid is used to make electricity. This solar power plant uses mirrors to focus sunlight on the tower in the center. The sunlight heats a liquid inside the tower to a very high temperature, producing energy to make electricity. "
high energy efficiency is desirable because,(A) Less energy is wasted (B) Non-renewable resources last longer (C) The cost is kept lower (D) All of these,D,"We can get more work out of the energy we use. Table 20.3 show some ways to use energy more efficiently. By getting more bang for the buck, we wont need to use as much energy overall. Does your family use energy efficiently? How could you find out? Use of Energy More Efficient Use Another way to use energy more efficiently is with Energy Star appliances. They carry the Energy Star logo, shown in Figure 20.14. To be certified as Energy Star, the appliance must use less energy. Energy Star appliances save a lot of energy over their lifetime. What if millions of households used Energy Star appliances? How much energy would it save? "
as a society we should make choices to use energy that is more efficient.,(A) True (B) False,A,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
the breakdown of chemicals to produce food energy.,(A) Hydrothermal vent (B) Photosynthesis (C) Chemosynthesis (D) Subduction,C,"The sum of all of an organisms biochemical reactions is called metabolism. Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. You can watch an animation showing how the two categories of reactions are related at this link: Anabolic reactions involve forming bonds. Smaller molecules combine to form larger ones. These reactions require energy. For example, it takes energy to build starches from sugars. Catabolic reactions involve breaking bonds. Larger molecules break down to form smaller ones. These reactions release energy. For example, energy is released when starches break down to sugars. "
bacteria that can make food using chemicals are called chemosythetic bacteria.,(A) True (B) False,A,"Bacteria can also be chemotrophs. Chemosynthetic bacteria, or chemotrophs, obtain energy by breaking down chemical compounds in their environment. An example of one of these chemicals broken down by bacteria is nitrogen-containing ammonia. These bacteria are important because they help cycle nitrogen through the environ- ment for other living things to use. Nitrogen cannot be made by living organisms, so it must be continually recycled. Organisms need nitrogen to make organic compounds, such as DNA. "
a large underwater structure created from the calcium carbonate skeletons of tiny animals is,(A) An atoll (B) A lagoon (C) A coral reef (D) A tide pool,C,"Corals and other animals deposit calcium carbonate to create rock reefs near the shore. Coral reefs are the rain- forests of the oceans, with a tremendous amount of species diversity (Figure 1.2). Reefs can form interesting shapes in the oceans. Remember that hot spots create volcanoes on the seafloor. If these volcanoes rise above sea level to become islands, and if they occur in tropical waters, coral reefs will form on them. Since the volcanoes are cones, the reef forms in a circle around the volcano. As the volcano comes off the hot spot, the crust cools. The volcano subsides and then begins to erode away (Figure 1.3). Eventually, all that is left is a reef island called an atoll. A lagoon is found inside the reef. "
a coral reef that surrounds a volcano is called a/an:,(A) Atoll (B) Lagoon (C) Pahoehoe (D) Aa,A,"Corals and other animals deposit calcium carbonate to create rock reefs near the shore. Coral reefs are the rain- forests of the oceans, with a tremendous amount of species diversity (Figure 1.2). Reefs can form interesting shapes in the oceans. Remember that hot spots create volcanoes on the seafloor. If these volcanoes rise above sea level to become islands, and if they occur in tropical waters, coral reefs will form on them. Since the volcanoes are cones, the reef forms in a circle around the volcano. As the volcano comes off the hot spot, the crust cools. The volcano subsides and then begins to erode away (Figure 1.3). Eventually, all that is left is a reef island called an atoll. A lagoon is found inside the reef. "
what is the main food source in the ocean?,(A) Zooplankton (B) Phytoplankton (C) Sea Anemone (D) Fish,B,"Figure 14.29 shows a marine food chain. Phytoplankton form the base of the food chain. Phytoplankton are the most important primary producers in the ocean. They use sunlight and nutrients to make food by photosynthesis. Small zooplankton consume phytoplankton. Larger organisms eat the small zooplankton. Larger predators eat these consumers. In an unusual relationship, some enormous whales depend on plankton for their food. They filter tremendous amounts of these tiny creatures out of the water. The bacteria that make food from chemicals are also primary producers. These organisms do not do photosynthesis since there is no light at the vents. They do something called chemosynthesis. They break down chemicals to make food. When marine organisms die, decomposers break them down. This returns their nutrients to the water. The nutrients can be used again to make food. Decomposers in the oceans include bacteria and worms. Many live on the ocean floor. Do you know why? "
coral reefs rival rainforests in species productivity and biomass.,(A) True (B) False,A,"The oceans provide a home to many living things. In fact, a greater number of organisms lives in the oceans than on land. Coral reefs, like the one in Figure 14.4, have more diversity of life forms than almost anywhere else on Earth. "
the sea anemones are well adapted to their environments because they have strong attachments and can close during high tides.,(A) True (B) False,B,"Conditions in the intertidal zone change rapidly as water covers and uncovers the region and waves pound on the rocks. A great abundance of life is found in the intertidal zone (Figure 1.1). High energy waves hit the organisms that live in this zone, so they must be adapted to pounding waves and exposure to air during low tides. Hard shells protect from waves and also protect against drying out when the animal is above water. Strong attachments keep the animals anchored to the rock. In a tide pool, as in the photo, what organisms are found where and what specific adaptations do they have to that zone? The mussels on the top left have hard shells for protection and to prevent drying because they are often not covered by water. The sea anemones in the lower right are more often submerged and have strong attachments but can close during low tides. Many young organisms get their start in estuaries and so they must be adapted to rapid shifts in salinity. Organisms in a tide pool include sea stars and sea urchins. Click image to the left or use the URL below. URL: "
"to live in the intertidal zone, organisms must be able to",(A) Withstand pounding waves (B) Not dry out when exposed to air (C) Keep from washing out to sea (D) All of these,D,"Conditions in the intertidal zone change rapidly as water covers and uncovers the region and waves pound on the rocks. A great abundance of life is found in the intertidal zone (Figure 1.1). High energy waves hit the organisms that live in this zone, so they must be adapted to pounding waves and exposure to air during low tides. Hard shells protect from waves and also protect against drying out when the animal is above water. Strong attachments keep the animals anchored to the rock. In a tide pool, as in the photo, what organisms are found where and what specific adaptations do they have to that zone? The mussels on the top left have hard shells for protection and to prevent drying because they are often not covered by water. The sea anemones in the lower right are more often submerged and have strong attachments but can close during low tides. Many young organisms get their start in estuaries and so they must be adapted to rapid shifts in salinity. Organisms in a tide pool include sea stars and sea urchins. Click image to the left or use the URL below. URL: "
the most difficult environmental condition for an animal that lives in a tide pool is tolerating rapid shifts in salinity.,(A) True (B) False,A,"Conditions in the intertidal zone change rapidly as water covers and uncovers the region and waves pound on the rocks. A great abundance of life is found in the intertidal zone (Figure 1.1). High energy waves hit the organisms that live in this zone, so they must be adapted to pounding waves and exposure to air during low tides. Hard shells protect from waves and also protect against drying out when the animal is above water. Strong attachments keep the animals anchored to the rock. In a tide pool, as in the photo, what organisms are found where and what specific adaptations do they have to that zone? The mussels on the top left have hard shells for protection and to prevent drying because they are often not covered by water. The sea anemones in the lower right are more often submerged and have strong attachments but can close during low tides. Many young organisms get their start in estuaries and so they must be adapted to rapid shifts in salinity. Organisms in a tide pool include sea stars and sea urchins. Click image to the left or use the URL below. URL: "
how do fish survive in the deepest ocean?,(A) They use very little energy (B) They are adapted to take advantage of any chance of a meal (C) They spend little energy building their bodies or bones (D) All of these,D,"The open ocean is a vast area. Food either washes down from the land or is created by photosynthesizing plankton. Zooplankton and larger animals feed on the phytoplankton and on each other. Larger animals such as whales and giant groupers may live their entire lives in the open water. How do fish survive in the deepest ocean? The few species that live in the greatest depths are very specialized (Figure 1.4). Since its rare to find a meal, the fish use very little energy; they move very little, breathe slowly, have minimal bone structure and a slow metabolism. These fish are very small. To maximize the chance of getting a meal, some species may have jaws that unhinge to accept a larger fish or backward-folding teeth to keep prey from escaping. Coral reefs are among the most densely inhabited and diverse areas on the globe. In this image of Maupiti Island in the South Pacific, the remnants of the volcano are surrounded by the circular reef. An 1896 drawing of a deep sea angler fish with a bioluminescent lure to attract prey. "
about _______ of garbage is from land.,(A) 50% (B) 60% (C) 70% (D) 80%,D,"Trash from land may end up as trash in the ocean, sometimes extremely far from land. Some of it will eventually wash ashore, possibly far from where it originated (Figure 1.1). "
80% of the trash that ends up in the oceans is,(A) Glass (B) Oil (C) Plastic (D) Chemical,C,"Although people had once thought that the trash found everywhere at sea was from ships, it turns out that 80% is from land. Some of that is from runoff, some is blown from nearshore landfills, and some is dumped directly into the sea. The 20% that comes from ships at sea includes trash thrown overboard by large cruise ships and many other vessels. It also includes lines and nets from fishing vessels. Ghost nets, nets abandoned by fishermen intentionally or not, float the seas and entangle animals so that they cannot escape. Containers sometimes go overboard in storms. Some noteworthy events, like a container of rubber ducks that entered the sea in 1992, are used to better understand ocean currents. The ducks went everywhere! "
plastic in the ocean,(A) Dissolves into toxic chemical sludge (B) Does not break down at all (C) Breaks down into molecule-sized polymers (D) Biodegrades into nontoxic substances,C,"One way that the ocean is becoming polluted is with trash, mainly plastics. The waste comes from shipping accidents, landfill erosion, and the dumping of trash. Plastics may take hundreds or even thousands of years to break down. In the meantime, the waste can be very dangerous to aquatic organisms. Some organisms may swallow plastic bags, for example, and others may be strangled by plastic six-pack rings. You can see some of the trash that routinely washes up on coastlines in Figure 25.7. There are five massive garbage patches floating on the Pacific Ocean. Watch this video to learn more about them:  . MEDIA Click image to the left or use the URL below. URL: "
plastic trash may contain toxic chemicals like __________ that enter the ocean.,(A) Bisphenol A (B) Pesticides (C) Herbicides (D) All of the above,A,"Some plastics contain toxic chemicals, such as bisphenol A. Plastics can also absorb organic pollutants that may be floating in the water, such as the pesticide DDT (which is banned in the U.S. but not in other nations) and some endocrine disruptors. "
"these extremely abundant plastics, when ingested can clog digestion and cause starvation.",(A) Plastic bottle caps (B) Plastic shopping bags (C) Plastic bottles (D) Plastic cups,B,"Marine birds, such as albatross, or animals like sea turtles, live most of their lives at sea and just come ashore to mate. These organisms cant break down the plastic and they may eventually die (Figure 1.2). Boats may be affected. Plastic waste is estimated to kill 100,000 sea turtles and marine mammals annually, but exact numbers are unknown. Plastic shopping bags are extremely abundant in the oceans. If an organism accidentally ingests one, it may clog digestion and cause starvation by stopping food from moving through or making the animal not feel hungry. In some areas, plastics have seven times the concentration of zooplankton. This means that filter feeders are ingesting a lot of plastics. This may kill the organisms or the plastics may remain in their bodies. They are then eaten by larger organisms that store the plastics and may eventually die. Fish may eat organisms that have eaten plastic and then be eaten by people. This also exposes humans to toxic chemicals that the fish may have ingested with the plastic. There are similar patches of trash in the gyres of the North Atlantic and Indian oceans. The Southern Hemisphere has less trash buildup because less of the region is continent. "
it takes about 100 years for trash to move from north america to the center of the north pacific gyre.,(A) True (B) False,B,"Trash from the lands all around the North Pacific is caught up in currents. The currents bring the trash into the center of the North Pacific Gyre. Scientists estimate that it takes about six years for trash to move from west coast of North America to the center of the gyre. The concentration of trash increases toward the center of the gyre. While recognizable pieces of garbage are visible, much of the trash is tiny plastic polymers that are invisible but can be detected in water samples. The particles are at or just below the surface within the gyre. Plastic confetti-like pieces are visible beneath the surface at the gyres center. This albatross likely died from the plastic it had ingested. The size of the garbage patch is unknown, since it cant be seen from above. Some people estimate that its twice the size of continental U.S, with a mass of 100 million tons. "
the north pacific gyre is estimated to have a mass of 100 million tons.,(A) True (B) False,A,"Trash from the lands all around the North Pacific is caught up in currents. The currents bring the trash into the center of the North Pacific Gyre. Scientists estimate that it takes about six years for trash to move from west coast of North America to the center of the gyre. The concentration of trash increases toward the center of the gyre. While recognizable pieces of garbage are visible, much of the trash is tiny plastic polymers that are invisible but can be detected in water samples. The particles are at or just below the surface within the gyre. Plastic confetti-like pieces are visible beneath the surface at the gyres center. This albatross likely died from the plastic it had ingested. The size of the garbage patch is unknown, since it cant be seen from above. Some people estimate that its twice the size of continental U.S, with a mass of 100 million tons. "
plastic trash in the oceans is hazardous to living things because,(A) The trash contains toxic chemicals that can be ingested (B) The trash can clog up an organism’s digestive system (C) A top predator may eat smaller organisms and accumulate all of their trash and toxic chemicals (D) All of these,D,"One way that the ocean is becoming polluted is with trash, mainly plastics. The waste comes from shipping accidents, landfill erosion, and the dumping of trash. Plastics may take hundreds or even thousands of years to break down. In the meantime, the waste can be very dangerous to aquatic organisms. Some organisms may swallow plastic bags, for example, and others may be strangled by plastic six-pack rings. You can see some of the trash that routinely washes up on coastlines in Figure 25.7. There are five massive garbage patches floating on the Pacific Ocean. Watch this video to learn more about them:  . MEDIA Click image to the left or use the URL below. URL: "
"in the gyre, plastic is present as particles, confetti-like pieces and as intact trash.",(A) True (B) False,A,"Trash from the lands all around the North Pacific is caught up in currents. The currents bring the trash into the center of the North Pacific Gyre. Scientists estimate that it takes about six years for trash to move from west coast of North America to the center of the gyre. The concentration of trash increases toward the center of the gyre. While recognizable pieces of garbage are visible, much of the trash is tiny plastic polymers that are invisible but can be detected in water samples. The particles are at or just below the surface within the gyre. Plastic confetti-like pieces are visible beneath the surface at the gyres center. This albatross likely died from the plastic it had ingested. The size of the garbage patch is unknown, since it cant be seen from above. Some people estimate that its twice the size of continental U.S, with a mass of 100 million tons. "
what is the submersible that descended the deepest into the challenger deep?,(A) Alvin (B) Deepsea Explorer (C) Trieste (D) Deepspace 9,C,"Only a specially designed vehicle can venture beneath the sea surface. But only very special vehicles can reach the ocean floor. Three are described here and pictured in Figure 14.21: In 1960, scientists used the submersible Trieste to travel into the Mariana Trench. They succeeded, but the trip was very risky. Making humans safe at such depths costs a lot of money. People have not traveled to this depth again. In 2012, the film director, James Cameron, dove to the bottom of the Mariana Trench by himself in a submersible that he had built for the purpose. The vehicle named Alvin was developed soon after Trieste. The submersible has made over 4,000 dives deep into the ocean. People can stay underwater for up to 9 hours. Alvin has been essential for developing a scientific understanding the worlds oceans. Today, remote-control vehicles, called remotely operated vehicles (ROVs) go to the deepest ocean floor. They dont have any people on board. However, they carry devices that record many measurements. They also collect sediments and take photos. "
"nearly all of the food is the ocean is made in the _______________ zone, but nearly all of the water in the ocean is in the ________________ zone.",(A) Photic; aphotic (B) A photic; photic (C) luminescent; aluminescent (D) aluminescent; luminescent,A,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
"photosynthesis takes place at the surface of the ocean, which means that",(A) Most creatures live very near the surface of the ocean (B) Most plants live at the surface (C) but most animals live much deeper down (D) c Most animals live at the surface (E) but most plants live deeper down (F) d Most creatures live deeper to take advantage of the chemosynthesis taking place there,A,"Only the top 200 meters or so of water receive enough sunlight for photosynthesis. This part of the water is called the photic zone. Below 200 meters, there is too little sunlight for photosynthesis to take place. This part of the water is called the aphotic zone. In this zone, food must come from other sources. It may be made by chemosynthesis, in which microorganisms use energy in chemicals instead of sunlight to make food. Or, food may drift down from the water above. "
which of these is a division in the horizontal zone?,(A) Intertidal (B) Neritic (C) Oceanic (D) All of the above,D,Oceanographers divide the ocean into zones both vertically and horizontally. 
the photic zone is around 200 meters in all oceans.,(A) True (B) False,B,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
the neritic zone is the zone where,(A) Photosynthesis takes place (B) The high and low tides marks form the boundaries (C) Sunlight doesn’t penetrate (D) None of these,D,"The seabed is divided into the zones described above, but ocean itself is also divided horizontally by distance from the shore. Nearest to the shore lies the intertidal zone (also called the littoral zone), the region between the high and low tidal marks. The hallmark of the intertidal is change: water is in constant motion in the form of waves, tides, and currents. The land is sometimes under water and sometimes exposed. The neritic zone is from low tide mark and slopes gradually downward to the edge of the seaward side of the continental shelf. Some sunlight penetrates to the seabed here. The oceanic zone is the entire rest of the ocean from the bottom edge of the neritic zone, where sunlight does not reach the bottom. The sea bed and water column are subdivided further, as seen in the Figure 1.1. Click image to the left or use the URL below. URL: "
"to live in the intertidal zone, an animal must be able to",(A) Photosynthesize (B) Deal with change (C) Live in the dark (D) Live in a tidepool,B,"Conditions in the intertidal zone change rapidly as water covers and uncovers the region and waves pound on the rocks. A great abundance of life is found in the intertidal zone (Figure 1.1). High energy waves hit the organisms that live in this zone, so they must be adapted to pounding waves and exposure to air during low tides. Hard shells protect from waves and also protect against drying out when the animal is above water. Strong attachments keep the animals anchored to the rock. In a tide pool, as in the photo, what organisms are found where and what specific adaptations do they have to that zone? The mussels on the top left have hard shells for protection and to prevent drying because they are often not covered by water. The sea anemones in the lower right are more often submerged and have strong attachments but can close during low tides. Many young organisms get their start in estuaries and so they must be adapted to rapid shifts in salinity. Organisms in a tide pool include sea stars and sea urchins. Click image to the left or use the URL below. URL: "
why is life at the bottom of the ocean sparse?,(A) There is no light (B) The pressure is extreme (C) It is exceedingly cold (D) All of the above,D,"The open ocean is a vast area. Food either washes down from the land or is created by photosynthesizing plankton. Zooplankton and larger animals feed on the phytoplankton and on each other. Larger animals such as whales and giant groupers may live their entire lives in the open water. How do fish survive in the deepest ocean? The few species that live in the greatest depths are very specialized (Figure 1.4). Since its rare to find a meal, the fish use very little energy; they move very little, breathe slowly, have minimal bone structure and a slow metabolism. These fish are very small. To maximize the chance of getting a meal, some species may have jaws that unhinge to accept a larger fish or backward-folding teeth to keep prey from escaping. Coral reefs are among the most densely inhabited and diverse areas on the globe. In this image of Maupiti Island in the South Pacific, the remnants of the volcano are surrounded by the circular reef. An 1896 drawing of a deep sea angler fish with a bioluminescent lure to attract prey. "
the zone at the bottom of the challenger deep is called the,(A) Bathy pelagic (B) Epipelagic (C) Hadal pelagic (D) Abyssal pelagic,C,"Two main zones based on depth of water are the photic zone and aphotic zone. The photic zone is the top 200 meters of water. The aphotic zone is water deeper than 200 meters. The deeper you go, the darker the water gets. Thats because sunlight cannot penetrate very far under water. Sunlight is needed for photosynthesis. So the depth of water determines whether photosynthesis is possible. There is enough sunlight for photosynthesis only in the photic zone. Water also gets colder as you go deeper. The weight of the water pressing down from above increases as well. At great depths, life becomes very difficult. The pressure is so great that only specially adapted creatures can live there. "
the largest oil spill in the united states waters was,(A) The Santa Barbara oil spill in 1969 (B) The Hawaiian Patriot in Honolulu (C) Hawaii in 1977 (D) c The Exxon Valdez spill in Alaska in 1989 (E) d The Deepwater Horizon spill in the Gulf of Mexico spill in 2010,D,"Large oil spills, like the Exxon Valdez in Alaska in 1989, get a lot of attention, as they should. Besides these large spills, though, much more oil enters the oceans from small leaks that are only a problem locally. In this concept, well take a look at a large recent oil spill in the Gulf of Mexico. "
"the deepwater horizon spill of 2010,",(A) Injured a few workers and sank an offshore drilling rig (B) Took place mostly in Mexican waters (C) Was caused by an explosion on a deepwater oil rig (D) All of these,C,"Working on oil platforms is dangerous. Workers are exposed to harsh ocean conditions and gas explosions. The danger was never more obvious than on April 20, 2010, when 11 workers were killed and 17 injured in an explosion on a deepwater oil rig in the Gulf of Mexico (Figure 1.1). The drilling rig, operated by BP, was 77 km (48 miles) offshore and the depth to the well was more than 5,000 feet. The U.S. Coast Guard tries to put out the fire and search for missing workers after the explosion on the Deepwater Horizon drilling rig. Eleven workers were killed. "
what is true about deepwater drilling?,(A) It is technologically very difficult (B) It opens up petroleum deposits that were never accessible before (C) It is extremely risky (D) All of the above,D,"New drilling techniques have allowed oil companies to drill in deeper waters than ever before. This allows us to access oil deposits that were never before accessible, but only with great technological difficulty. The risks from deepwater drilling and the consequences when something goes wrong are greater than those associated with shallower wells. "
the deepwater horizon spill __________ barrels of oil a day entered the gulf.,(A) 10 (B) 000 to 20 (C) 000 (D) b 25 (E) 000 to 35 (F) 000 (G) c 35 (H) 000 to 60 (I) 000 (J) d 60 (K) 000 to 75 (L) 000,C,"Two days after the explosion, the drill rig sank. The 5,000-foot pipe that connected the wellhead to the drilling platform bent. Oil was free to gush into the Gulf of Mexico from nearly a mile deep (Figure 1.2). Initial efforts to cap or contain the spill at or near its source all failed to stop the vast oil spill. It was not until July 15, nearly three months after the accident, that the well was successfully capped. Estimating the flow of oil into the Gulf from the well was extremely difficult because the leak was so far below the surface. The U.S. government estimates that about 4.9 million barrels entered the Gulf at a rate of 35,000 to 60,000 barrels a day. The largest previous oil spill in the United States was of 300,000 barrels by the Exxon Valdez in 1989 in Prince William Sound, Alaska. "
oil companies will continue to go for hard-to-get-at deposits as long as,(A) People will pay for the oil (B) They are interested in meeting the technological challenge (C) There is oil to get (D) None of these,A,"New drilling techniques have allowed oil companies to drill in deeper waters than ever before. This allows us to access oil deposits that were never before accessible, but only with great technological difficulty. The risks from deepwater drilling and the consequences when something goes wrong are greater than those associated with shallower wells. "
dispersal of oil,(A) Is not naturally effective (B) With chemicals may cause more harm to the environment than the oil itself (C) Can often be accomplished with a small amount of chemical dispersants (D) With chemicals is a simple (E) harmless process,B,"Once the oil is in the water, there are three types of methods for dealing with it: 1. Removal: Oil is corralled and then burned; natural gas is flared off (Figure 1.3). Machines that can separate oil from the water are placed aboard ships stationed in the area. These ships cleaned tens of thousands of barrels of contaminated seawater each day. 2. Containment: Floating containment booms are placed on the surface offshore of the most sensitive coastal areas in an attempt to attempt to trap the oil. But the seas must be calm for the booms to be effective, and so were not very useful in the Gulf (Figure 1.4). Sand berms have been constructed off of the Louisiana coast to keep the oil from reaching shore. (a) On May 17, 2010, oil had been leaking into the Gulf for nearly one month. On that date government estimates put the maximum total oil leak at 1,600,000 barrels, according to the New York Times. (b) The BP oil spill on June 19, 2010. The government estimates for total oil leaked by this date was 3,200,000 barrels. 3. Dispersal: Oil disperses naturally over time because it mixes with the water. However, such large amounts of oil will take decades to disperse. To speed the process up, BP has sprayed unprecedented amounts of chemical dispersants on the spill. That action did not receive support from the scientific community since no one knows the risks to people and the environment from such a large amount of these harmful chemicals. Some workers may have become ill from exposure to the chemicals. "
one of the ways to clean up spilled oil is to,(A) Corral it and then burn it (B) Blow it onto shore where it won’t damage marine creatures (C) Drop giant sponges on it then burn the sponges (D) Get boats with propellers into it to mix the oil with the water,A,"Once the oil is in the water, there are three types of methods for dealing with it: 1. Removal: Oil is corralled and then burned; natural gas is flared off (Figure 1.3). Machines that can separate oil from the water are placed aboard ships stationed in the area. These ships cleaned tens of thousands of barrels of contaminated seawater each day. 2. Containment: Floating containment booms are placed on the surface offshore of the most sensitive coastal areas in an attempt to attempt to trap the oil. But the seas must be calm for the booms to be effective, and so were not very useful in the Gulf (Figure 1.4). Sand berms have been constructed off of the Louisiana coast to keep the oil from reaching shore. (a) On May 17, 2010, oil had been leaking into the Gulf for nearly one month. On that date government estimates put the maximum total oil leak at 1,600,000 barrels, according to the New York Times. (b) The BP oil spill on June 19, 2010. The government estimates for total oil leaked by this date was 3,200,000 barrels. 3. Dispersal: Oil disperses naturally over time because it mixes with the water. However, such large amounts of oil will take decades to disperse. To speed the process up, BP has sprayed unprecedented amounts of chemical dispersants on the spill. That action did not receive support from the scientific community since no one knows the risks to people and the environment from such a large amount of these harmful chemicals. Some workers may have become ill from exposure to the chemicals. "
"when we no longer hear about an oil spill in the news, it is because the region has been cleaned up and is back to normal.",(A) True (B) False,B,"Large oil spills, like the Exxon Valdez in Alaska in 1989, get a lot of attention, as they should. Besides these large spills, though, much more oil enters the oceans from small leaks that are only a problem locally. In this concept, well take a look at a large recent oil spill in the Gulf of Mexico. "
which of the following is not true?,(A) Seabirds dive into an oil slick because the surface looks like calmer water (B) Plankton (C) which form the base of the marine food chain (D) are killed by oil (E) c Whales and dolphins are killed by oil and/or the chemical dispersants (F) d Petroleum acts like a fertilizer to increase the amount of life in an area with a spill,D,"If the hypothesis above about falling objects really were false, it is likely that this would be discovered sooner or later after enough objects had been dropped. It takes just one exception to disprove a hypothesis. But what if the hypothesis really is true? Can this be demonstrated as well? No; it would require testing all possible combinations of objects to show that they always reach the ground at the same time. This is impossible. New objects are being made all the time that would have to be tested. Its always possible an exception would be found in the future to disprove the hypothesis. Although you cant prove conclusively that a hypothesis is true, the more evidence you gather in support of it, the more likely it is to be true. "
more oil enters the oceans from small leaks than from large spills.,(A) True (B) False,A,"Large oil spills, like the Exxon Valdez in Alaska in 1989, get a lot of attention, as they should. Besides these large spills, though, much more oil enters the oceans from small leaks that are only a problem locally. In this concept, well take a look at a large recent oil spill in the Gulf of Mexico. "
the green revolution has resulted in,(A) Increased the human population (B) Many more people to be fed (C) Land loss (D) pollution and fossil fuel use (E) d All of the above,D,The Green Revolution has brought enormous impacts to the planet. 
"overall, the percentage of people in the world that live in abject poverty is decreasing.",(A) True (B) False,A,"The addition of more people has not just resulted in more poor people. A large percentage of people expect much more than to have their basic needs met. For about one-quarter of people there is an abundance of food, plenty of water, and a secure home. Comfortable temperatures are made possible by heating and cooling systems, rapid trans- portation is available by motor vehicles or a well-developed public transportation system, instant communication takes place by phones and email, and many other luxuries are available that were not even dreamed of only a few The percentage of people in the world that live in abject poverty is decreasing some- what globally, but increasing in some re- gions, such as Sub-Saharan Africa. decades ago. All of these require resources in order to be produced, and fossil fuels in order to be powered (Figure Many people refer to the abundance of luxury items in these peoples lives as over-consumption. People in developed nations use 32 times more resources than people in the developing countries of the world. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
which of these regions is experiencing an increase in abject poverty?,(A) East Asia (B) Europe (C) Sub-Saharan Africa (D) Latin America,C,"The addition of more people has not just resulted in more poor people. A large percentage of people expect much more than to have their basic needs met. For about one-quarter of people there is an abundance of food, plenty of water, and a secure home. Comfortable temperatures are made possible by heating and cooling systems, rapid trans- portation is available by motor vehicles or a well-developed public transportation system, instant communication takes place by phones and email, and many other luxuries are available that were not even dreamed of only a few The percentage of people in the world that live in abject poverty is decreasing some- what globally, but increasing in some re- gions, such as Sub-Saharan Africa. decades ago. All of these require resources in order to be produced, and fossil fuels in order to be powered (Figure Many people refer to the abundance of luxury items in these peoples lives as over-consumption. People in developed nations use 32 times more resources than people in the developing countries of the world. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
about 1 million of the worlds people do not have enough clean water for drinking.,(A) True (B) False,B,"Many people in the world have no choice but to drink from the same polluted river where sewage is dumped. One- fifth of all people in the world, more than 1.1 billion people, do not have access to safe water for drinking, personal cleanliness, and domestic use. Unsafe drinking water carries many pathogens, or disease-causing biological agents such as infectious bacteria and parasites. Toxic chemicals and radiological hazards in water can also cause diseases. "
global resources are distributed equally across the planet.,(A) True (B) False,B,"Rich nations use more natural resources than poor nations. In fact, the richest 20 percent of people use 85 percent of the worlds resources. What about the poorest 20 percent of people? They use only 1 percent of the worlds resources. You can see this unequal distribution of oil resources in Figure 20.3. Imagine a world in which everybody had equal access to resources. Some people would have fewer resources than they do now. But many people would have more. In the real world, the difference between rich and poor just keeps growing. "
"since the use of burning fossil fuels for energy, this waste product has increased.",(A) H20 (B) CO2 (C) O2 (D) None of the above,C,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
due to increased agriculture brought about by the green revolution,(A) More people are living and working on farms (B) Natural landscapes increasingly are being altered for human uses (C) Less pollution is coming off these “green” farms (D) All of the above,B,The Green Revolution has brought enormous impacts to the planet. 
what is the cause of dead zones?,(A) Fertilizer drains off farmland and introduces excess nutrients to lakes and seas (B) Land is cleared for farms (C) Land is altered and the sediment that is released ends up in a lake or sea (D) None of these,A,"Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. Every year dead zones appear in lakes and nearshore waters. A dead zone is an area of hundreds of kilometers of ocean without fish or plant life. The Mississippi is not the only river that carries the nutrients necessary to cause a dead zone. Rivers that drain regions where human population density is high and where crops are grown create dead zones all over the world (Figure 1.2). "
"basic human necessities are food, clean water, secure shelter and basic sanitation.",(A) True (B) False,A,"The increased numbers of people have other impacts on the planet. Humans do not just need food. They also need clean water, secure shelter, and a safe place for their wastes. These needs are met to different degrees in different nations and among different socioeconomic classes of people. For example, about 1.2 billion of the worlds people do not have enough clean water for drinking and washing each day (Figure 1.2). "
over-consumption refers to,(A) The amount of resources used by an average human on Earth (B) The amount of resources used by the number of people that cause overpopulation (C) The excess resources used by wealthy people mostly in developed countries (D) The amount of resources used by a poor person on Earth,C,"The topic of overconsumption was touched on in the chapter Life on Earth. Many people in developed countries, such as the United States and most of Europe, use many more natural resources than people in many other countries. We have many luxury and recreational items, and it is often cheaper for us to throw something away than to fix it or just hang on to it for a while longer. This consumerism leads to greater resource use, but it also leads to more waste. Pollution from discarded materials degrades the land, air, and water (Figure 1.3). Natural resource use is generally lower in developing countries because people cannot afford many products. Some of these nations export natural resources to the developed world since their deposits may be richer and the cost of labor lower. Environmental regulations are often more lax, further lowering the cost of resource extraction. Click image to the left or use the URL below. URL:  The nations in blue are the 12 biggest producers of oil; they are Algeria, Angola, Ecuador, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, the United Arab Emirates, and Venezuela. Pollution from discarded materials de- grades the environment and reduces the availability of natural resources. "
"in the troposphere, ozone is a pollutant.",(A) True (B) False,A,"At this point you might be asking yourself, Is ozone bad or is ozone good? There is no simple answer to that question: It depends on where the ozone is located (Figure 1.1). In the troposphere, ozone is a pollutant. In the ozone layer in the stratosphere, ozone screens out high energy ultraviolet radiation and makes Earth habitable. "
ozone in the stratosphere,(A) Is a pollutant (B) Protects the surface from UVC from the Sun (C) Is one of the main greenhouse gases (D) All of these,B,Ozone near the ground harms human health. But the ozone layer in the stratosphere protects us from solar rays. Thats why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. 
cfc molecules destroy ozone because,(A) When they break apart (B) the chlorine pulls an oxygen atom off an ozone molecule (C) b The ozone freezes to the CFC and in the spring they both break apart (D) c Fluorine attaches to an ozone molecule (E) pulls an oxygen molecule off and forms FlO2 (F) d None of these,A,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
which of used to contain cfcs?,(A) Spray-can propellants (B) Refrigerants (C) Paints (D) All of the above,D,"One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone- destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs. "
the ozone hole is at its biggest each year in the __________ hemisphere in the __________ season.,(A) Northern Hemisphere; spring (B) Southern Hemisphere; fall (C) Southern Hemisphere; spring (D) Northern Hemisphere; fall,C,"Most ozone loss it taking place over the South Pole and Antarctica. This is the location of the ozone hole. The ozone hole is also seasonal. The hole forms during the early part spring in the Southern Hemisphere and then grows northward. You can see the hole in Figure 22.13. Besides the ozone hole, the ozone layer is thinner over the Northern Hemisphere. "
"once released into the air, cfcs float up to the stratosphere.",(A) True (B) False,A,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
antarctica is a good place for the ozone hole to form because,(A) It’s extremely cold and the CFCs freeze into the polar stratospheric clouds (B) More people are in the Southern Hemisphere so more CFCs are there (C) Air circulates move vigorously in this region (D) All of these,A,"Ozone destruction creates the ozone hole where the layer is dangerously thin (Figure 1.3). As air circulates over Antarctica in the spring, the ozone hole expands northward over the southern continents, including Australia, New Zealand, southern South America, and southern Africa. UV levels may rise as much as 20% beneath the ozone hole. The hole was first measured in 1981 when it was 2 million square km (900,000 square miles). The 2006 hole was the largest ever observed at 28 million square km (11.4 million square miles). The size of the ozone hole each year depends on many factors, including whether conditions are right for the formation of PSCs. The September 2006 ozone hole, the largest observed (through 2013). Blue and purple colors show particularly low levels of ozone. "
how does ozone loss affect humans and the environment?,(A) Increase in skin cancer (B) Decrease in phytoplankton productivity (C) Whales have sunburns (D) All of the above,D,"Ozone losses on human health and environment include: Increases in sunburns, cataracts (clouding of the lens of the eye), and skin cancers. A loss of ozone of only 1% is estimated to increase skin cancer cases by 5% to 6%. Decreases in the human immune systems ability to fight off infectious diseases. Reduction in crop yields because many plants are sensitive to ultraviolet light. Decreases in phytoplankton productivity. A decrease of 6% to 12% has been measured around Antarctica, which may be at least partly related to the ozone hole. The effects of excess UV on other organisms is not known. Whales in the Gulf of California have been found to have sunburned cells in their lowest skin layers, indicating very severe sunburns. The problem is greatest with light colored species or species that spend more time near the sea surface. When the problem with ozone depletion was recognized, world leaders took action. CFCs were banned in spray cans in some nations in 1978. The greatest production of CFCs was in 1986, but it has declined since then. This will be discussed more in the next concept. "
"over the north polar region, there is less ozone loss because",(A) Spring does not last as long and there is not time for the hole to form (B) The atmosphere is not as cold and there are not as many polar stratospheric clouds (C) CFC use is more restricted in this region (D) All of these,B,"Ozone loss also occurs over the North Polar Region, but it is not enough for scientists to call it a hole. Why do you think there is less ozone loss over the North Pole area? The region of low ozone levels is small because the atmosphere is not as cold and PSCs do not form as readily. Still, springtime ozone levels are relatively low. This low moves south over some of the worlds most populated areas in Europe, North America, and Asia. At 40o N, the latitude of New York City, UV-B has increased about 4% per decade since 1978. At 55o N, the approximate latitude of Moscow and Copenhagen, the increase has been 6.8% per decade since 1978. Click image to the left or use the URL below. URL: "
cfcs were completely banned in 1978 and the ozone hole has since declined.,(A) True (B) False,B,"One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone- destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs. "
a marine transgression is when,(A) Sea level retreats (B) Sea level rises over land (C) Sea level remains the same (D) Sea level rises and falls,B,"Some of the most important events of the Paleozoic and Mesozoic were the rising and falling of sea level over the continents. Sea level rises over the land during a marine transgression. During a marine regression, sea level retreats. During the Paleozoic there were four complete cycles of marine transgressions and regressions. There were two additional cycles during the Mesozoic (Figure 1.1). One of two things must happen for sea level to change in a marine transgression: either the land must sink or the water level must rise. What could cause sea level to rise? When little or no fresh water is tied up in glaciers and ice caps, sea level is high. Sea level also appears to rise if land is down dropped. Sea level rises if an increase in seafloor spreading rate buoys up the ocean crust, causing the ocean basin to become smaller. What could cause sea level to fall in a marine regression? Six marine transgressions and regres- sions have occurred during the Phanero- zoic. Geologists think that the Paleozoic marine transgressions and regressions were the result of the decrease and increase in the size of glaciers covering the lands. Click image to the left or use the URL below. URL: "
"during the paleozoic era, there were _____ complete cycles of marine transgressions and regressions.",(A) One (B) Two (C) Three (D) Four,D,"Some of the most important events of the Paleozoic and Mesozoic were the rising and falling of sea level over the continents. Sea level rises over the land during a marine transgression. During a marine regression, sea level retreats. During the Paleozoic there were four complete cycles of marine transgressions and regressions. There were two additional cycles during the Mesozoic (Figure 1.1). One of two things must happen for sea level to change in a marine transgression: either the land must sink or the water level must rise. What could cause sea level to rise? When little or no fresh water is tied up in glaciers and ice caps, sea level is high. Sea level also appears to rise if land is down dropped. Sea level rises if an increase in seafloor spreading rate buoys up the ocean crust, causing the ocean basin to become smaller. What could cause sea level to fall in a marine regression? Six marine transgressions and regres- sions have occurred during the Phanero- zoic. Geologists think that the Paleozoic marine transgressions and regressions were the result of the decrease and increase in the size of glaciers covering the lands. Click image to the left or use the URL below. URL: "
what can cause sea level to rise?,(A) Melting glaciers and ice caps (B) Down dropping land (C) Increasing seafloor spreading rates (D) All of the above,D,"Some of the most important events of the Paleozoic and Mesozoic were the rising and falling of sea level over the continents. Sea level rises over the land during a marine transgression. During a marine regression, sea level retreats. During the Paleozoic there were four complete cycles of marine transgressions and regressions. There were two additional cycles during the Mesozoic (Figure 1.1). One of two things must happen for sea level to change in a marine transgression: either the land must sink or the water level must rise. What could cause sea level to rise? When little or no fresh water is tied up in glaciers and ice caps, sea level is high. Sea level also appears to rise if land is down dropped. Sea level rises if an increase in seafloor spreading rate buoys up the ocean crust, causing the ocean basin to become smaller. What could cause sea level to fall in a marine regression? Six marine transgressions and regres- sions have occurred during the Phanero- zoic. Geologists think that the Paleozoic marine transgressions and regressions were the result of the decrease and increase in the size of glaciers covering the lands. Click image to the left or use the URL below. URL: "
the rock facies that represents a marine transgression from bottom to top is,(A) Limestone (B) shale (C) sandstone (D) b Shale (E) limestone (F) sandstone (G) c Sandstone (H) shale (I) limestone (J) d Limestone (K) sandstone (L) shale,C,"The Paleozoic sedimentary rocks of the Grand Canyon contain evidence of marine transgressions and regressions, but even there the rock record is not complete. Look at the sequence in the Figure 1.2 and see if you can determine whether the sea was transgressing or regressing. At the bottom, the Tonto Group represents a marine transgression: sandstone (11), shale (10), and limestone (9) laid down during 30 million years of the Cambrian Period. The Ordovician and Silurian are unknown because of an unconformity. Above that is freshwater limestone (8), which is overlain by limestone (7) and then shale (6), indicating that the sea was regressing. After another unconformity, the rocks of the Supai Group (5) include limestone, siltstone, and sandstone indicative of a regressing sea. Above those rocks are shale (4), sandstone (3), a limestone and sandstone mix (2) showing that the sea regressed and transgressed and finally limestone (1) indicating that the sea had come back in. "
shale is the rock that forms from halite and sand deposits.,(A) True (B) False,B,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
geologists think that the paleozoic marine transgressions and regressions were caused by decreasing and increasing glaciers.,(A) True (B) False,A,"Some of the most important events of the Paleozoic and Mesozoic were the rising and falling of sea level over the continents. Sea level rises over the land during a marine transgression. During a marine regression, sea level retreats. During the Paleozoic there were four complete cycles of marine transgressions and regressions. There were two additional cycles during the Mesozoic (Figure 1.1). One of two things must happen for sea level to change in a marine transgression: either the land must sink or the water level must rise. What could cause sea level to rise? When little or no fresh water is tied up in glaciers and ice caps, sea level is high. Sea level also appears to rise if land is down dropped. Sea level rises if an increase in seafloor spreading rate buoys up the ocean crust, causing the ocean basin to become smaller. What could cause sea level to fall in a marine regression? Six marine transgressions and regres- sions have occurred during the Phanero- zoic. Geologists think that the Paleozoic marine transgressions and regressions were the result of the decrease and increase in the size of glaciers covering the lands. Click image to the left or use the URL below. URL: "
"carbonate mud later hardens into ____________ in deep, low energy waters.",(A) Shale (B) Silt (C) Sandstone (D) Limestone,D,"Geologists know about marine transgressions and regressions from the sedimentary rock record. These events leave characteristic rock layers known as sedimentary facies. On a shoreline, sand and other coarse grained rock fragments are commonly found on the beach where the wave energy is high. Away from the shore in lower energy environments, fine-grained silt that later creates shale is deposited. In deeper, low-energy waters, carbonate mud that later hardens into limestone is deposited. "
a sequence of sandstone-shale-limestone-shale indicates,(A) A marine transgression and partial regression (B) A marine regression and partial transgression (C) A marine transgression and regression (D) A marine regression and transgression,A,"The Paleozoic sedimentary rocks of the Grand Canyon contain evidence of marine transgressions and regressions, but even there the rock record is not complete. Look at the sequence in the Figure 1.2 and see if you can determine whether the sea was transgressing or regressing. At the bottom, the Tonto Group represents a marine transgression: sandstone (11), shale (10), and limestone (9) laid down during 30 million years of the Cambrian Period. The Ordovician and Silurian are unknown because of an unconformity. Above that is freshwater limestone (8), which is overlain by limestone (7) and then shale (6), indicating that the sea was regressing. After another unconformity, the rocks of the Supai Group (5) include limestone, siltstone, and sandstone indicative of a regressing sea. Above those rocks are shale (4), sandstone (3), a limestone and sandstone mix (2) showing that the sea regressed and transgressed and finally limestone (1) indicating that the sea had come back in. "
much of what geologists know about paleozoic marine transgressions and regressions is from what is displayed at the grand canyon.,(A) True (B) False,A,"The Paleozoic sedimentary rocks of the Grand Canyon contain evidence of marine transgressions and regressions, but even there the rock record is not complete. Look at the sequence in the Figure 1.2 and see if you can determine whether the sea was transgressing or regressing. At the bottom, the Tonto Group represents a marine transgression: sandstone (11), shale (10), and limestone (9) laid down during 30 million years of the Cambrian Period. The Ordovician and Silurian are unknown because of an unconformity. Above that is freshwater limestone (8), which is overlain by limestone (7) and then shale (6), indicating that the sea was regressing. After another unconformity, the rocks of the Supai Group (5) include limestone, siltstone, and sandstone indicative of a regressing sea. Above those rocks are shale (4), sandstone (3), a limestone and sandstone mix (2) showing that the sea regressed and transgressed and finally limestone (1) indicating that the sea had come back in. "
the continents move around on earths surface but they are always centered near the equator.,(A) True (B) False,A,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
the phanerozoic,(A) Began with the supercontinent Pangaea and ended with the supercontinent Rodinia (B) Was the first era to come after the Precambrian (C) Was the second era of the Phanerozoic (D) All of these,B,"The Paleozoic is the furthest back era of the Phanerozoic and it lasted the longest. But the Paleozoic was relatively recent, beginning only 570 million years ago. Compared with the long expanse of the Precambrian, the Phanerozoic is recent history. Much more geological evidence is available for scientists to study so the Phanerozoic is much better known. The Paleozoic begins and ends with a supercontinent. At the beginning of the Paleozoic, the supercontinent Rodinia began to split up. At the end, Pangaea came together. "
when continents converge to make a supercontinent,(A) The convergent plate boundary goes from ocean-continent to continent-continent (B) Island arcs and microcontinents may also join in (C) Processes take place over tens or hundreds of millions of years (D) All of these,D,"Scientists think that Pangaea was not the first supercontinent. There were others before it. The continents are now moving together. This is because of subduction around the Pacific Ocean. Eventually, the Pacific will disappear and a new supercontinent will form. This wont be for hundreds of millions of years. The creation and breakup of a supercontinent takes place about every 500 million years. "
this mountain range grew much higher when gondwana and laurentia collided to create pangaea.,(A) The Cascades (B) The Himalayas (C) The Alps (D) The Appalachians,D,"A mountain-building event is called an orogeny. Orogenies take place over tens or hundreds of millions of years. As continents smash into microcontinents and island arcs collided, mountains rise. Geologists find evidence for the orogenies that took place while Pangaea was forming in many locations. For example, Laurentia collided with the Taconic Island Arc during the Taconic Orogeny (Figure 1.1). The remnants of this mountain range make up the Taconic Mountains in New York. The Taconic Orogeny is an example of a collision between a continent and a volcanic island arc. Laurentia experienced other orogenies as it merged with the northern continents. The southern continents came together to form Gondwana. When Laurentia and Gondwana collided to create Pangaea, the Appalachians rose. Geologists think they may once have been higher than the Himalayas are now. "
"eastern north america has a sequence of metamorphic rock, metamorphosed sedimentary rock and a volcanic arc. this is due to",(A) Convergence during the Taconic Orogeny (B) Convergence due to the Appalachian Orogeny (C) Divergence due to the opening of the Atlantic Ocean (D) Divergence during the Laurentian Orogeny,A,"The moving continents collided with island arcs and microcontinents so that mountain ranges accreted onto the continents edges. The subduction of the oceanic Farallon plate beneath western North America during the late In the Afar Region of Ethiopia, Africa is splitting apart. Three plates are pulling away from a central point. Jurassic and early Cretaceous produced igneous intrusions and other structures. The intrusions have since been uplifted so that they are exposed in the Sierra Nevada Mountains (Figure 1.2). The snow-covered Sierra Nevada is seen striking SE to NW across the eastern third of the image. The mountain range is a line of uplifted batholiths from Mesozoic subduction. Click image to the left or use the URL below. URL: "
the southern continents came together to form pangaea.,(A) True (B) False,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
pangaea was central to alfred wegeners continental drift hypothesis.,(A) True (B) False,A,"Alfred Wegener was an early 20th century German meteorologist. Wegener believed that the continents were once all joined together. He named the supercontinent Pangaea, meaning all earth. Wegener suggested that Pangaea broke up long ago. Since then, the continents have been moving to their current positions. He called his hypothesis continental drift. "
geologists think that the himalayas are the tallest mountains in earth history.,(A) True (B) False,B,"Most of the worlds largest mountains form as plates collide at convergent plate boundaries. Continents are too buoyant to get pushed down into the mantle. So when the plates smash together, the crust crumples upwards. This creates mountains. Folding and faulting in these collision zones makes the crust thicker. The worlds highest mountain range, the Himalayas, is growing as India collides with Eurasia. About 80 million years ago, India was separated from Eurasia by an ocean (Figure 7.16). As the plates collided, pieces of the old seafloor were forced over the Asian continent. This old seafloor is now found high in the Himalayas (Figure 7.17). "
"at the end of the paleozoic, there was/were",(A) One landmass (B) called Rodinia (C) and one super ocean (D) called Rodalassa (E) b Two landmasses (F) Laurentia and Gondwana (G) and one super ocean (H) called Panthalassa (I) c One landmass (J) called Pangaea (K) and one super ocean (L) called Panthalassa (M) d None of these,C,The Paleozoic saw the evolution a tremendous diversity of life throughout the seas and onto land. 
the remnants of the taconic mountain range are found in _______________.,(A) New York (B) California (C) Australia (D) Africa,A,"The moving continents collided with island arcs and microcontinents so that mountain ranges accreted onto the continents edges. The subduction of the oceanic Farallon plate beneath western North America during the late In the Afar Region of Ethiopia, Africa is splitting apart. Three plates are pulling away from a central point. Jurassic and early Cretaceous produced igneous intrusions and other structures. The intrusions have since been uplifted so that they are exposed in the Sierra Nevada Mountains (Figure 1.2). The snow-covered Sierra Nevada is seen striking SE to NW across the eastern third of the image. The mountain range is a line of uplifted batholiths from Mesozoic subduction. Click image to the left or use the URL below. URL: "
"in a car engine, gasoline burns to become gases, which expand when heated and move pistons to power the car.",(A) True (B) False,A,"Gasoline is a concentrated resource. It contains a large amount of energy for its weight. This is important because the more something weighs, the more energy is needed to move it. If gasoline could only provide a little energy, a car would have to carry a lot of it to be able to travel very far. Or the car would need to be filled up frequently. So a highly concentrated energy resource is a practical fuel to power cars and other forms of transportation. Lets consider how gasoline powers a car. As gasoline burns, it releases most of its energy as heat. It also releases carbon dioxide gas and water vapor. The heat makes the gases expand. This forces the pistons inside the engine to move. The engine makes enough power to move the car. "
crude oil is a mixture of many different,(A) Hydroxygens (B) Hydrocarbons (C) Carbon dioxides (D) Monoxides,B,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
"for people to be able to drill for oil, it must",(A) Be located within a groundwater aquifer (B) Be trapped in a strike-slip fault zone (C) Have collected beneath an impermeable rock layer (D) Have reached the surface at a point so people know it’s there,C,"New drilling techniques have allowed oil companies to drill in deeper waters than ever before. This allows us to access oil deposits that were never before accessible, but only with great technological difficulty. The risks from deepwater drilling and the consequences when something goes wrong are greater than those associated with shallower wells. "
refineries help to separate these from crude oil,(A) Petroleum (B) carbon dioxide and water vapor (C) b Gasoline (D) diesel and heating oil (E) c Hydrocarbons (F) carbon dioxide and water vapor (G) d Gasoline and carbon dioxide,B,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
which of these requires oil?,(A) Fertilizer (B) Plastic (C) Wax (D) All of the above,D,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
crude oil,(A) Is made entirely of ancient plants that lived in swamps (B) Is what we put in our gas tanks (C) Is a very liquid and volatile hydrocarbon (D) Must be refined to be useful,D,"Oil comes out of the ground as crude oil. Crude oil is a mixture of many different hydrocarbons. Oil is separated into different compounds at an oil refinery (Figure 5.4). This is done by heating the oil. Each hydrocarbon compound in crude oil boils at a different temperature. We get gasoline, diesel, and heating oil, plus waxes, plastics, and fertilizers from crude oil. These fuels are rich sources of energy. Since they are mostly liquids they can be easily transported. These fuels provide about 90% of the energy used for transportation around the world. "
which of these locations is not a main-oil producing region for the united states?,(A) Florida (B) The Gulf of Mexico (C) Texas (D) Alaska,A,"The United States produces only about one-quarter as much oil as it uses. The main oil producing regions in the U.S. are the Gulf of Mexico, Texas, Alaska, and California. Geologists look for oil in folded layers of rock called anticlines. Oil moves through permeable rock and is trapped by the impermeable cap rock. "
the united states produces about one-half as much oil as it uses.,(A) True (B) False,B,"The United States does produce oil, but the amount produced is only about one-quarter as much as the nation uses. The United States has only about 1.5% of the worlds proven oil reserves, so most of the oil used by Americans must be imported from other nations. The main oil-producing regions in the United States are the Gulf of Mexico, Texas, Alaska, and California (Figure As in every type of mining, mining for oil has environmental consequences. Oil rigs are unsightly (Figure 1.4), and spills are too common (Figure 1.5). Click image to the left or use the URL below. URL:  Offshore well locations in the Gulf of Mex- ico. Note that some wells are located in very deep water. Drill rigs at the San Ardo Oil Field in Monterey, California. "
"when gasoline burns, it turns into this.",(A) Heat (B) Water vapor (C) Carbon dioxide (D) All of the above,D,"Gasoline is a concentrated resource. It contains a large amount of energy for its weight. This is important because the more something weighs, the more energy is needed to move it. If gasoline could only provide a little energy, a car would have to carry a lot of it to be able to travel very far. Or the car would need to be filled up frequently. So a highly concentrated energy resource is a practical fuel to power cars and other forms of transportation. Lets consider how gasoline powers a car. As gasoline burns, it releases most of its energy as heat. It also releases carbon dioxide gas and water vapor. The heat makes the gases expand. This forces the pistons inside the engine to move. The engine makes enough power to move the car. "
the consequences of oil use include,(A) Having to deal with unfriendly nations (B) Oil spills (C) Pollution (D) All of the above,D,"People in the U.S. use far more energyespecially energy from oilthan people in any other nation. The bar graph in the Figure 1.2 compares the amount of oil used by the top ten oil-using nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels of oil a year. Q: How does the use of oil and other fossil fuels relate to pollution? A: Greater use of oil and other fossil fuels causes more pollution. "
the seasons are caused by,(A) Earth’s orbit around the Sun (B) Annual changes in solar radiation (C) The tilt of Earth’s axis (D) Changes in atmospheric circulation,C,"Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. Different areas also receive different amounts of sunlight in different seasons. What causes the seasons? The seasons are caused by the direction Earths axis is pointing relative to the Sun. The Earth revolves around the Sun once each year and spins on its axis of rotation once each day. This axis of rotation is tilted 23.5o relative to its plane of orbit around the Sun. The axis of rotation is pointed toward Polaris, the North Star. As the Earth orbits the Sun, the tilt of Earths axis stays lined up with the North Star. "
what is the shape of a planets orbit?,(A) Circular (B) Triangular (C) Rectangular (D) Elliptical,D,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
who discovered the relationship between a planets orbital period and the distance from the sun?,(A) Nicolaus Copernicus (B) Johannes Kepler (C) Isaac Newton (D) Galilieo Galilei,B,"Figure 1.1 shows the relative sizes of the orbits of the planets, asteroid belt, and Kuiper belt. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. The orbits of the planets are not circular but slightly elliptical, with the Sun located at one of the foci (see opening image). While studying the solar system, Johannes Kepler discovered the relationship between the time it takes a planet to make one complete orbit around the Sun, its ""orbital period,"" and the distance from the Sun to the planet. If the orbital period of a planet is known, then it is possible to determine the planets distance from the Sun. This is how astronomers without modern telescopes could determine the distances to other planets within the solar system. How old are you on Earth? How old would you be if you lived on Jupiter? How many days is it until your birthday on Earth? How many days until your birthday if you lived on Saturn? Click image to the left or use the URL below. URL:  The relative sizes of the orbits of planets in the solar system. The inner solar sys- tem and asteroid belt is on the upper left. The upper right shows the outer planets and the Kuiper belt. "
the planet in the solar system with the largest orbital period is,(A) Mercury (B) Earth (C) Jupiter (D) Neptune,D,"Copernicus, Galileo, and Kepler were all right: Earth and the other planets travel in an elliptical orbit around the Sun. The gravitational pull of the Sun keeps the planets in orbit. This ellipse is barely elliptical; its very close to being a circle. The closest Earth gets to the Sun each year is at perihelion (147 million km) on about January 3rd, and the furthest is at aphelion (152 million km) on July 4th. The shape of Earths orbit has nothing to do with Earths seasons. Earth and the other planets in the solar system make elliptical orbits around the Sun. For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year. Earth has one large moon, which orbits Earth once every 29.5 days, a period known as a month. Click image to the left or use the URL below. URL: "
"the closer two adjacent planets are from the sun, the farther the distance from one planets orbit to the other.",(A) True (B) False,B,"Figure 1.1 shows the relative sizes of the orbits of the planets, asteroid belt, and Kuiper belt. In general, the farther away from the Sun, the greater the distance from one planets orbit to the next. The orbits of the planets are not circular but slightly elliptical, with the Sun located at one of the foci (see opening image). While studying the solar system, Johannes Kepler discovered the relationship between the time it takes a planet to make one complete orbit around the Sun, its ""orbital period,"" and the distance from the Sun to the planet. If the orbital period of a planet is known, then it is possible to determine the planets distance from the Sun. This is how astronomers without modern telescopes could determine the distances to other planets within the solar system. How old are you on Earth? How old would you be if you lived on Jupiter? How many days is it until your birthday on Earth? How many days until your birthday if you lived on Saturn? Click image to the left or use the URL below. URL:  The relative sizes of the orbits of planets in the solar system. The inner solar sys- tem and asteroid belt is on the upper left. The upper right shows the outer planets and the Kuiper belt. "
mars has the smallest orbit in our solar system.,(A) True (B) False,B,"Mercury is the smallest planet. It has no moon. The planet is also closest to the Sun and appears in Figure 25.7. As Figure 25.8 shows, the surface of Mercury is covered with craters, like Earths Moon. The presence of impact craters that are so old means that Mercury hasnt changed much geologically for billions of years. With only a trace of an atmosphere, it has no weather to wear down the ancient craters. Because Mercury is so close to the Sun, it is difficult to observe from Earth, even with a telescope. The Mariner 10 spacecraft did a flyby of Mercury in 19741975, which was the best data from the planet for decades. In 2004, the MESSENGER mission left Earth. On its way to Mercury it did one flyby of Earth, two of Venus and three of Mercury. In March 2011, MESSENGER became the first spacecraft to enter an orbit around Mercury. During its year-long mission, the craft will map the planets surface and conduct other studies. One of these images can be seen in Figure 25.9. "
the time it takes a planet to make one complete orbit around the sun is known as its ____________.,(A) Orbital period (B) Time of revolution (C) Elliptical period (D) Speed,A,"Copernicus, Galileo, and Kepler were all right: Earth and the other planets travel in an elliptical orbit around the Sun. The gravitational pull of the Sun keeps the planets in orbit. This ellipse is barely elliptical; its very close to being a circle. The closest Earth gets to the Sun each year is at perihelion (147 million km) on about January 3rd, and the furthest is at aphelion (152 million km) on July 4th. The shape of Earths orbit has nothing to do with Earths seasons. Earth and the other planets in the solar system make elliptical orbits around the Sun. For Earth to make one complete revolution around the Sun takes 365.24 days. This amount of time is the definition of one year. Earth has one large moon, which orbits Earth once every 29.5 days, a period known as a month. Click image to the left or use the URL below. URL: "
"if the asteroid belt is a planet that didnt come together, we would expect the asteroids to be the right orbital distance between mars and jupiter.",(A) True (B) False,A,"Hundreds of thousands of asteroids have been found in our solar system. They are still being discovered at a rate of about 5,000 new asteroids per month! The majority are located in between the orbits of Mars and Jupiter. This region is called the asteroid belt, as shown in Figure 25.32. There are many thousands of asteroids in the asteroid belt. Still, their total mass adds up to only about 4 percent of Earths Moon. Asteroids formed at the same time as the rest of the solar system. Although there are many in the asteroid belt, they were never were able to form into a planet. Jupiters gravity kept them apart. "
how did scientists determine a planets distance from the sun before the invention of modern telescopes?,(A) The distance is directly related to the amount of time it takes for the planet to rotate once on its axis (B) By observing the size of the planet (C) The distance is directly related to the planet’s orbital period (D) None of these,C,"Even with the most precise instruments available, parallax is too small to measure the distance to stars that are more than a few hundred light years away. For these more distant stars, astronomers must use more indirect methods of determining distance. Most of these methods involve determining how bright the star they are looking at really is. For example, if the star has properties similar to the Sun, then it should be about as bright as the Sun. The astronomer compares the observed brightness to the expected brightness. "
scientists now must know exactly where a planet is and will be in the future if they are going to send spacecraft to see it.,(A) True (B) False,A,"Observations of Earths surface may be made from the land surface or from space. Many important observations are made by orbiting satellites, which have a birds eye view of how the planet is changing (for example, see Figure Often, observation is used to collect data when it is not possible for practical or ethical reasons to perform experi- ments. Scientists may send devices to make observations for them when it is too dangerous or impractical for them to make the observations directly. They may use microscopes to explore tiny objects or telescopes to learn about the universe (see Figure 1.2). Artists concept of the Juno orbiter circling Jupiter. The mission is ongoing. "
which of these is a dwarf planet?,(A) Jupiter (B) Uranus (C) Pluto (D) Venus,C,"Eris is the largest known dwarf planet in the solar system  it has about 27% more mass than Pluto (Figure 1.3). The object was not discovered until 2003 because it is about three times farther from the Sun than Pluto, and almost 100 times farther from the Sun than Earth is. For a short time Eris was considered the tenth planet in the solar system, but its discovery helped to prompt astronomers to better define planets and dwarf planets in 2006. Eris also has a small moon, Dysnomia, that orbits it once about every 16 days. Astronomers know there may be other dwarf planets in the outer reaches of the solar system. Haumea was made a dwarf planet in 2008, so the total number of dwarf planets is now five. Quaoar, Varuna, and Orcus may be added to the list of dwarf planets in the future. We still have a lot to discover and explore. Click image to the left or use the URL below. URL: "
"through his telescope, galileo could see all the planets of the solar system.",(A) True (B) False,B,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
the sun is _______ more the mass of the entire solar system combined.,(A) 10 times (B) 20 times (C) 200 times (D) 500 times,D,"Since the time of Copernicus, Kepler, and Galileo, we have learned a lot more about our solar system. Astronomers have discovered two more planets (Uranus and Neptune), five dwarf planets (Ceres, Pluto, Makemake, Haumea, and Eris), more than 150 moons, and many, many asteroids and other small objects. Although the Sun is just an average star compared to other stars, it is by far the largest object in the solar system. The Sun is more than 500 times the mass of everything else in the solar system combined! Table 1.1 gives data on the sizes of the Sun and planets relative to Earth. Object Mass (Relative to Earth) Sun Mercury Venus Earth 333,000 Earths mass 0.06 Earths mass 0.82 Earths mass 1.00 Earths mass Diameter of Planet (Relative to Earth) 109.2 Earths diameter 0.39 Earths diameter 0.95 Earths diameter 1.00 Earths diameter Object Mass (Relative to Earth) Mars Jupiter Saturn Uranus Neptune 0.11 Earths mass 317.8 Earths mass 95.2 Earths mass 14.6 Earths mass 17.2 Earths mass Diameter of Planet (Relative to Earth) 0.53 Earths diameter 11.21 Earths diameter 9.41 Earths diameter 3.98 Earths diameter 3.81 Earths diameter "
distance in the solar system is measured by _______________.,(A) Miles (B) Kilometers (C) Astronomical units (D) Light years,C,"Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km, or 93 million miles. Table 1.2 shows the distances to the planets (the average radius of orbits) in AU. The table also shows how long it takes each planet to spin on its axis (the length of a day) and how long it takes each planet to complete an orbit (the length of a year); in particular, notice how slowly Venus rotates relative to Earth. Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year (In Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 Click image to the left or use the URL below. URL: "
the sun is _________________________ million miles from earth.,(A) 93 (B) 73 (C) 53 (D) 33,A,"We need a really big unit to measure distances out in space because distances between stars are so great. A light- year, 9.5 trillion kilometers (5.9 trillion miles), is the distance that light travels in one year. Thats a long way! Out in space, its actually a pretty short distance. Proxima Centauri is the closest star to us after the Sun. This near neighbor is 4.22 light-years away. That means the light from Proxima Centauri takes 4.22 years to reach us. Our galaxy, the Milky Way Galaxy, is about 100,000 light-years across. So it takes light 100,000 years to travel from one side of the galaxy to the other! It turns out that even 100,000 light years is a short distance. The most distant galaxies we have detected are more than 13 billion light-years away. Thats over a hundred-billion-trillion kilometers! "
on venus a day is equal to 243 earth days. what does this mean?,(A) The length of a planet’s day is inversely related to its distance from the Sun (B) The length of a planet’s day is directly related to its distance from the Sun (C) Venus takes 243 Earth days to rotate once on its axis (D) Venus takes 243 Earth days to orbit the Sun once,C,"Venus rotates in a direction opposite the other planets and opposite to the direction it orbits the Sun. This rotation is extremely slow, only one turn every 243 Earth days. This is longer than a year on Venus  it takes Venus only 224 days to orbit the Sun. Diagram of Venuss interior, which is simi- lar to Earths. "
one astronomical unit is 93 million miles.,(A) True (B) False,A,"Distances in the solar system are often measured in astronomical units (AU). One astronomical unit is defined as the distance from Earth to the Sun. 1 AU equals about 150 million km, or 93 million miles. Table 1.2 shows the distances to the planets (the average radius of orbits) in AU. The table also shows how long it takes each planet to spin on its axis (the length of a day) and how long it takes each planet to complete an orbit (the length of a year); in particular, notice how slowly Venus rotates relative to Earth. Planet Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Average Distance from Sun (AU) 0.39 AU 0.72 1.00 1.52 5.20 9.54 19.22 30.06 Length of Day (In Earth Days) 56.84 days 243.02 1.00 1.03 0.41 0.43 0.72 0.67 Length of Year (In Earth Years) 0.24 years 0.62 1.00 1.88 11.86 29.46 84.01 164.8 Click image to the left or use the URL below. URL: "
on which planet would your weight be closest to your weight on earth?,(A) Mercury (B) Venus (C) Mars (D) Jupiter,B,"If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force. Mass and weight are closely related. However, the weight of an object can change if the force of gravity changes. On Earth, the force of gravity is the same everywhere. So how does the force of gravity change? It doesnt if you stay on Earth. What if we travel to another planet or moon in our solar system? Look at the photo of astronaut Edwin E. Aldrin Jr. taken by fellow astronaut Neil Armstrong in the Figure ??. They were the first humans to walk on the moon. An astronaut weighs less on the moon than he would on Earth. This is because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. If the astronaut weighed 175 pounds on Earth, he would have weighed only 29 pounds on the moon. If his mass on Earth was 80 kg, what would his mass have been on the moon? [Figure 3] "
how is ceres different from the other four dwarf planets?,(A) Ceres is nearly as large as Mercury; the others are much smaller (B) Ceres orbits near Jupiter; the others orbit beyond Neptune (C) Ceres has microbial life (D) but life hasn’t been found on the others yet (E) d All of these,B,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
about how many times has mercury been around the sun in the time it has taken earth to go around ten times?,(A) once (B) 25-times (C) 4-times (D) 40-times,D,"Mercury is named for the Roman messenger god, who could run extremely quickly, just as the planet moves very quickly in its orbit around the Sun. A year on Mercury  the length of time it takes to orbit the Sun  is just 88 Earth days. Despite its very short years, Mercury has very long days. A day is defined as the time it takes a planet to turn on its axis. Mercury rotates slowly on its axis, turning exactly three times for every two times it orbits the Sun. Therefore, each day on Mercury is 57 Earth days long. In other words, on Mercury, a year is only a Mercury day and a half long! "
a small body of fresh water with no stream draining it.,(A) Lakes (B) Ponds (C) Ocean (D) Stream,B,"Ponds are small bodies of fresh water that usually have no outlet; ponds are often are fed by underground springs. Like lakes, ponds are bordered by hills or low rises so the water is blocked from flowing directly downhill. "
which of these is not full of fresh water?,(A) The Great Lakes (B) Glaciers (C) The Great Salt Lake (D) Ponds,C,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
the water in crater lake in oregon is within a(n),(A) Caldera in a volcano (B) Fault zone (C) Glacially carved basin (D) Impact Crater,A,"Prior to the Mount St. Helens eruption in 1980, the Lassen Peak eruption on May 22, 1915, was the most recent Cascades eruption. A column of ash and gas shot 30,000 feet into the air. This triggered a high-speed pyroclastic flow, which melted snow and created a volcanic mudflow known as a lahar. Lassen Peak currently has geothermal activity and could erupt explosively again. Mt. Shasta, the other active volcano in California, erupts every 600 to 800 years. An eruption would most likely create a large pyroclastic flow, and probably a lahar. Of course, Mt. Shasta could explode and collapse like Mt. Mazama in Oregon (Figure 1.4). Crater Lake fills the caldera of the col- lapsed Mt. Mazama, which erupted with 42 times more power than Mount St. He- lens in 1980. The bathymetry of the lake shows volcanic features such as cinder cones. "
the great lake basins were made from,(A) Calderas in a supervolcano (B) Erosion due to giant floods (C) A set of meteorite impact craters (D) Glacially carved rocks,D,"The depression that allows water to collect to form a lake may come about in a variety of ways. The Great Lakes, for example, are glacial lakes. A glacial lake forms when a glacier scrapes a large hole in the ground. When the glacier melts, the water fills the hole and forms a lake. Over time, water enters the lake from the sources mentioned above as well. Other lakes are crater lakes or rift lakes, which are pictured in Figure 13.8. Crater lakes form when volcanic eruptions create craters that fill with water. Rift lakes form when movements of tectonic plates create low places that fill with water. "
every lake you see was formed naturally.,(A) True (B) False,B,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
lakes formed in canada were from glaciers that covered north america in the last ice age.,(A) True (B) False,A,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
"lakes change with time, including",(A) Rising and falling with the season (B) Filling with sediment (C) Getting deeper with erosion (D) All of these,D,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
lakes are not like the ocean because they are made of fresh water and they do not have tides or currents.,(A) True (B) False,B,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
large lakes,(A) Have living organisms at the surface but are too deep for life to live at the bottom (B) Only form in fault zones where blocks of crust drop down to form a basin (C) Alter weather by increasing snow downwind (D) All of these,C,"Lakes are larger bodies of water. Lakes are usually fresh water, although the Great Salt Lake in Utah is just one exception. Water usually drains out of a lake through a river or a stream and all lakes lose water to evaporation. Lakes form in a variety of different ways: in depressions carved by glaciers, in calderas (Figure 1.1), and along tectonic faults, to name a few. Subglacial lakes are even found below a frozen ice cap. As a result of geologic history and the arrangement of land masses, most lakes are in the Northern Hemisphere. In fact, more than 60% of all the worlds lakes are in Canada  most of these lakes were formed by the glaciers that covered most of Canada in the last Ice Age (Figure 1.2). Lakes are not permanent features of a landscape. Some come and go with the seasons, as water levels rise and fall. Over a longer time, lakes disappear when they fill with sediments, if the springs or streams that fill them diminish, (a) Crater Lake in Oregon is in a volcanic caldera. Lakes can also form in volcanic craters and impact craters. (b) The Great Lakes fill depressions eroded as glaciers scraped rock out from the landscape. (c) Lake Baikal, ice coated in winter in this image, formed as water filled up a tectonic faults. Lakes near Yellowknife were carved by glaciers during the last Ice Age. or if their outlets grow because of erosion. When the climate of an area changes, lakes can either expand or shrink (Figure 1.3). Lakes may disappear if precipitation significantly diminishes. Large lakes have tidal systems and currents, and can even affect weather patterns. The Great Lakes in the United States contain 22% of the worlds fresh surface water (Figure 1.1). The largest them, Lake Superior, has a tide that rises and falls several centimeters each day. The Great Lakes are large enough to alter the weather system in Northeastern United States by the lake effect, which is an increase in snow downwind of the relatively warm lakes. The Great Lakes are home to countless species of fish and wildlife. Many lakes are not natural, but are human-made. People dam a stream in a suitable spot and then let the water back up behind it, creating a lake. These lakes are called ""reservoirs."" Click image to the left or use the URL below. URL: "
the great salt lake is salty because,(A) Fresh water drains out of the lake and leaves salt behind (B) Fresh water evaporates and leaves salt behind (C) The lake formed on a halite formation and that salt has since dissolved into the lake (D) None of these,B,You know that ocean water is salty. But do you know why? How salty is it? 
when does a population shrink?,(A) The number of births equals the number of deaths (B) The number of births is greater than the number of deaths (C) The number of births is less than the number of deaths (D) Randomly,C,The growth of the human population has started to slow down. You can see this in Figure 18.21. It may stop growing by the mid 2000s. Scientists think that the human population will peak at about 9 billion people. What will need to change for the population to stop growing then? 
a region will be at its carrying capacity if,(A) The number of births equals the number of deaths (B) The number of births is greater than the number of deaths (C) The number of deaths is greater than the number of births (D) The resources are being used faster than they are being replenished,A,"When the number of births equals the number of deaths, the population is at its carrying capacity for that habitat. In a population at its carrying capacity, there are as many organisms of that species as the habitat can support. The carrying capacity depends on biotic and abiotic factors. If these factors improve, the carrying capacity increases. If the factors become less plentiful, the carrying capacity drops. If resources are being used faster than they are being replenished, then the species has exceeded its carrying capacity. If this occurs, the population will then decrease in size. "
the size of a population in an ecosystem is determined by,(A) Biotic factors such as the food available and the competition for that food (B) Abiotic factors such as space (C) water and climate (D) c The carrying capacity of the ecosystem for that species (E) d All of the above,D,"Population size is the number of individuals in a population. Population size influences the chances of a species surviving or going extinct. If a species populations become very small, the species may be at risk of going extinct. "
"if a pack of coyotes enters a region, the carrying capacity for bunnies will likely",(A) Decrease (B) Increase (C) Not be impacted (D) Respond randomly,A,"When the number of births equals the number of deaths, the population is at its carrying capacity for that habitat. In a population at its carrying capacity, there are as many organisms of that species as the habitat can support. The carrying capacity depends on biotic and abiotic factors. If these factors improve, the carrying capacity increases. If the factors become less plentiful, the carrying capacity drops. If resources are being used faster than they are being replenished, then the species has exceeded its carrying capacity. If this occurs, the population will then decrease in size. "
"besides changes in births and deaths, immigration in or out of a region can also change a population.",(A) True (B) False,A,"Migration is the movement of individual organisms into, or out of, a population. Migration affects population growth rate. There are two types of migration: 1. Immigration is the movement of individuals into a population from other areas. This increases the population size and growth rate. 2. Emigration is the movement of individuals out of a population. This decreases the population size and growth rate. The earlier growth rate equation can be modified to account for migration: growth rate = (birth rate + immigration rate) (death rate + emigration rate). One type of migration that you are probably familiar with is the migration of birds. Maybe you have heard that birds fly south for the winter. In the fall, birds fly thousands of miles to the south where it is warmer. In the spring, they return to their homes. ( Figure 1.2). Monarch butterflies also migrate from Mexico to the northern U.S. in the summer and back to Mexico in the winter. These types of migrations move entire populations from one location to another. A flock of barnacle geese fly in formation during the autumn migration. "
"for a given species in a given habitat, the limiting factor is always the same thing.",(A) True (B) False,B,"Every stable population has one or more factors that limit its growth. A limiting factor determines the carrying capacity for a species. A limiting factor can be any biotic or abiotic factor: nutrient, space, and water availability are examples (Figure 1.1). The size of a population is tied to its limiting factor. What happens if a limiting factor increases a lot? Is it still a limiting factor? If a limiting factor increases a lot, another factor will most likely become the new limiting factor. This may be a bit confusing, so lets look at an example of limiting factors. Say you want to make as many chocolate chip cookies as you can with the ingredients you have on hand. It turns out that you have plenty of flour and other ingredients, but only two eggs. You can make only one batch of cookies, because eggs are the limiting factor. But then your neighbor comes over with a dozen eggs. Now you have enough eggs for seven batches of cookies, but only two pounds of butter. You can make four batches of cookies, with butter as the limiting factor. If you get more butter, some other ingredient will be limiting. Species ordinarily produce more offspring than their habitat can support (Figure 1.2). If conditions improve, more young survive and the population grows. If conditions worsen, or if too many young are born, there is competition between individuals. As in any competition, there are some winners and some losers. Those individuals that survive to fill the available spots in the niche are those that are the most fit for their habitat. Click image to the left or use the URL below. URL:  A frog in frog spawn. An animal produces many more offspring than will survive. "
why do some animals produce many more offspring than their habitat can support?,(A) If conditions improve and more can be supported in the habitat (B) they will be ready (C) b If conditions worsen (D) competition will ensure that the fittest survive (E) c To be sure that some will survive (F) d All of the above,D,"When the number of births equals the number of deaths, the population is at its carrying capacity for that habitat. In a population at its carrying capacity, there are as many organisms of that species as the habitat can support. The carrying capacity depends on biotic and abiotic factors. If these factors improve, the carrying capacity increases. If the factors become less plentiful, the carrying capacity drops. If resources are being used faster than they are being replenished, then the species has exceeded its carrying capacity. If this occurs, the population will then decrease in size. "
what is an important abiotic factor to help a population grow?,(A) Predators (B) Space (C) Food supply (D) All of the above,B,"Biotic and abiotic factors determine the population size of a species in an ecosystem. What are some important biotic factors? Biotic factors include the amount of food that is available to that species and the number of organisms that also use that food source. What are some important abiotic factors? Space, water, and climate all help determine a species population. When does a population grow? A population grows when the number of births is greater than the number of deaths. When does a population shrink? When deaths exceed births. What causes a population to grow? For a population to grow there must be ample resources and no major problems. What causes a population to shrink? A population can shrink either because of biotic or abiotic limits. An increase in predators, the emergence of a new disease, or the loss of habitat are just three possible problems that will decrease a population. A population may also shrink if it grows too large for the resources required to support it. "
"if a population uses needed resources faster than they are being replenished, the population",(A) Has yet to reach its carrying capacity (B) Will continue to grow forever (C) Has exceeded its carrying capacity (D) None of these,C,"Every 20 minutes, the human population adds 3,500 more people. More people need more resources. For example, we now use five times more fossil fuels than we did in 1970. The human population is expected to increase for at least 40 years. What will happen to resource use? "
a limiting factor determines the carrying capacity for a species.,(A) True (B) False,A,"Every stable population has one or more factors that limit its growth. A limiting factor determines the carrying capacity for a species. A limiting factor can be any biotic or abiotic factor: nutrient, space, and water availability are examples (Figure 1.1). The size of a population is tied to its limiting factor. What happens if a limiting factor increases a lot? Is it still a limiting factor? If a limiting factor increases a lot, another factor will most likely become the new limiting factor. This may be a bit confusing, so lets look at an example of limiting factors. Say you want to make as many chocolate chip cookies as you can with the ingredients you have on hand. It turns out that you have plenty of flour and other ingredients, but only two eggs. You can make only one batch of cookies, because eggs are the limiting factor. But then your neighbor comes over with a dozen eggs. Now you have enough eggs for seven batches of cookies, but only two pounds of butter. You can make four batches of cookies, with butter as the limiting factor. If you get more butter, some other ingredient will be limiting. Species ordinarily produce more offspring than their habitat can support (Figure 1.2). If conditions improve, more young survive and the population grows. If conditions worsen, or if too many young are born, there is competition between individuals. As in any competition, there are some winners and some losers. Those individuals that survive to fill the available spots in the niche are those that are the most fit for their habitat. Click image to the left or use the URL below. URL:  A frog in frog spawn. An animal produces many more offspring than will survive. "
the first crust was made of this rock.,(A) Granite (B) Gneiss (C) Limestone (D) Basalt,D,"The first crust was made of basaltic rock, like the current ocean crust. Partial melting of the lower portion of the basaltic crust began more than 4 billion years ago. This created the silica-rich crust that became the felsic continents. "
the first felsic continental crust came from,(A) Silica-rich minerals that floated on the magma ocean (B) Partial melting of the lower portion of the basaltic crust (C) Asteroid and comet impacts (D) None of these,B,"The first crust was made of basaltic rock, like the current ocean crust. Partial melting of the lower portion of the basaltic crust began more than 4 billion years ago. This created the silica-rich crust that became the felsic continents. "
greenstones in cratons indicate that at the time they formed,(A) There was felsic continental crust (B) There was an atmosphere (C) There were subduction zones (D) All of the above,C,"The earliest felsic continental crust is now found in the ancient cores of continents, called the cratons. Rapid plate motions meant that cratons experienced many continental collisions. Little is known about the paleogeography, or the ancient geography, of the early planet, although smaller continents could have come together and broken up. Geologists can learn many things about the Pre-Archean by studying the rocks of the cratons. Cratons also contain felsic igneous rocks, which are remnants of the first continents. Cratonic rocks contain rounded sedimentary grains. Of what importance is this fact? Rounded grains indicate that the minerals eroded from an earlier rock type and that rivers or seas also existed. One common rock type in the cratons is greenstone, a metamorphosed volcanic rock (Figure 1.1). Since greenstones are found today in oceanic trenches, what does the presence of greenstones mean? These ancient greenstones indicate the presence of subduction zones. Ice age glaciers scraped the Canadian Shield down to the 4.28 billion year old greenstone in Northwestern Quebec. "
cratons,(A) Contain grains that were eroded from earlier rocks (B) Are found in the ancient interiors of some continents (C) Contain felsic and mafic igneous rocks (D) All of these,D,"In most places the cratons were covered by younger rocks, which together are called a platform. Sometimes the younger rocks eroded away to expose the Precambrian craton (Figure 1.3). "
precambrian shields are about,(A) 570 million years old (B) 670 million years old (C) 770 million years old (D) 870 million years old,A,"Places the craton crops out at the surface is known as a shield. Cratons date from the Precambrian and are called Precambrian shields. Many Precambrian shields are about 570 million years old (Figure 1.2). The Canadian Shield is the ancient flat part of Canada that lies around Hudson Bay, the northern parts of Minnesota, Wisconsin and Michigan and much of Greenland. "
"at the grand canyon, the layered sedimentary rocks are on top of ancient precambrian craton. this is called a",(A) Greenstone (B) Platform (C) Shield (D) Cratonic layer,B,"Youre standing in the Grand Canyon and you see rocks like those in the Figure 1.1. Using the rules listed above, try to figure out the geologic history of the geologic column. The Grand Canyon is full mostly of sedimentary rocks, which are important for deciphering the geologic history of a region. In the Grand Canyon, the rock layers are exposed like a layer cake. Each layer is made of sediments that were deposited in a particular environment - perhaps a lake bed, shallow offshore region, or a sand dune. (a) The rocks of the Grand Canyon are like a layer cake. (b) A geologic column showing the rocks of the Grand Canyon. In this geologic column of the Grand Canyon, the sedimentary rocks of groups 3 through 6 are still horizontal. Group 2 rocks have been tilted. Group 1 rocks are not sedimentary. The oldest layers are on the bottom and youngest are on the top. The ways geologists figure out the geological history of an area will be explored more in the chapter Earth History. Click image to the left or use the URL below. URL: "
the presence of zircons in ancient rocks indicates that there was water in the environment.,(A) True (B) False,A,"The early atmosphere was rich in water vapor from volcanic eruptions and comets. When Earth was cool enough, water vapor condensed and rain began to fall. The water cycle began. Over millions of years enough precipitation collected that the first oceans could have formed as early as 4.2 to 4.4 billion years ago. Dissolved minerals carried by stream runoff made the early oceans salty. What geological evidence could there be for the presence of an early ocean? Marine sedimentary rocks can be dated back about 4 billion years. By the Archean, the planet was covered with oceans and the atmosphere was full of water vapor, carbon dioxide, nitrogen, and smaller amounts of other gases. Click image to the left or use the URL below. URL: "
when earths interior was warmer than it is now,(A) Mantle convection was faster (B) Plate tectonics processes were faster (C) Subduction was more common so plates were relatively small (D) All of these,D,"During the Pre-Archean and Archean, Earths interior was warmer than today. Mantle convection was faster and plate tectonics processes were more vigorous. Since subduction zones were more common, the early crustal plates were relatively small. Since the time that it was completely molten, Earth has been cooling. Still, about half the internal heat that was generated when Earth formed remains in the planet and is the source of the heat in the core and mantle today. "
earth has not cooled since right after the moon formed because of radioactivity.,(A) True (B) False,B,"There are no lakes, rivers, or even small puddles anywhere to be found on the Moons surface. So there is no running water and no atmosphere. This means that there is no erosion. Natural processes continually alter the Earths surface. Without these processes, our planets surface would be covered with meteorite craters just like the Moon. Many moons in our solar system have cratered surfaces. NASA scientists have discovered a large number of water molecules mixed in with lunar dirt. There is also surface water ice. Even though there is a very small amount of water, there is no atmosphere. Temperatures are extreme. So it comes as no surprise that there has not been evidence of life on the Moon. "
"in the snowball earth hypothesis,",(A) Earth was covered by ice at the end of the Precambrian (B) When the ice melted (C) life evolved rapidly (D) c The Ediacara fauna evolved in the Cambrian (E) d All of these,D,"Here is the main evidence that Wegener and his supporters collected for the continental drift hypothesis: The continents appear to fit together. Ancient fossils of the same species of extinct plants and animals are found in rocks of the same age but are on continents that are now widely separated (Figure 1.1). Wegener proposed that the organisms had lived side by side, but that the lands had moved apart after they were dead and fossilized. His critics suggested that the organisms moved over long-gone land bridges, but Wegener thought that the organisms could not have been able to travel across the oceans. Fossils of the seed fern Glossopteris were too heavy to be carried so far by wind. Mesosaurus was a swimming reptile, but could only swim in fresh water. Cynognathus and Lystrosaurus were land reptiles and were unable to swim. Wegener used fossil evidence to support his continental drift hypothesis. The fos- sils of these organisms are found on lands that are now far apart. Identical rocks, of the same type and age, are found on both sides of the Atlantic Ocean. Wegener said the rocks had formed side by side and that the land had since moved apart. Mountain ranges with the same rock types, structures, and ages are now on opposite sides of the Atlantic Ocean. The Appalachians of the eastern United States and Canada, for example, are just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway (Figure 1.2). Wegener concluded that they formed as a single mountain range that was separated as the continents drifted. Grooves and rock deposits left by ancient glaciers are found today on different continents very close to the Equator. This would indicate that the glaciers either formed in the middle of the ocean and/or covered most of the Earth. Today, glaciers only form on land and nearer the poles. Wegener thought that the glaciers were centered over the southern land mass close to the South Pole and the continents moved to their present positions later on. The similarities between the Appalachian and the eastern Greenland mountain ranges are evidences for the continental drift hypothesis. Coral reefs and coal-forming swamps are found in tropical and subtropical environments, but ancient coal seams and coral reefs are found in locations where it is much too cold today. Wegener suggested that these creatures were alive in warm climate zones and that the fossils and coal later drifted to new locations on the continents. Wegener thought that mountains formed as continents ran into each other. This got around the problem of the leading hypothesis of the day, which was that Earth had been a molten ball that bulked up in spots as it cooled (the problem with this idea was that the mountains should all be the same age and they were known not to be). Click image to the left or use the URL below. URL: "
how did continents form during the precambrian?,(A) Cratons converged with microcontinents and oceanic island arcs (B) Felsic minerals floated to the top of the magma ocean (C) then cooled (D) c The supercontinent Pangaea broke apart (E) d All of these,A,"By the end of the Archean, about 2.5 billion years ago, plate tectonics processes were completely recognizable. Small Proterozoic continents known as microcontinents collided to create supercontinents, which resulted in the uplift of massive mountain ranges. The history of the North American craton is an example of what generally happened to the cratons during the Precambrian. As the craton drifted, it collided with microcontinents and oceanic island arcs, which were added to the continents. Convergence was especially active between 1.5 and 1.0 billion years ago. These lands came together to create the continent of Laurentia. About 1.1 billion years ago, Laurentia became part of the supercontinent Rodinia (Figure 1.1). Rodinia probably contained all of the landmass at the time, which was about 75% of the continental landmass present today. Rodinia broke up about 750 million years ago. The geological evidence for this breakup includes large lava flows that are found where continental rifting took place. Seafloor spreading eventually started and created the oceans between the continents. The breakup of Rodinia may have triggered Snowball Earth around 700 million years ago. "
evidence for the breakup of rodinia includes,(A) Large mountain ranges where continents came together (B) Large lava flows where continents rifted apart (C) Subduction zones where the continents rifted apart (D) All of these,B,"By the end of the Archean, about 2.5 billion years ago, plate tectonics processes were completely recognizable. Small Proterozoic continents known as microcontinents collided to create supercontinents, which resulted in the uplift of massive mountain ranges. The history of the North American craton is an example of what generally happened to the cratons during the Precambrian. As the craton drifted, it collided with microcontinents and oceanic island arcs, which were added to the continents. Convergence was especially active between 1.5 and 1.0 billion years ago. These lands came together to create the continent of Laurentia. About 1.1 billion years ago, Laurentia became part of the supercontinent Rodinia (Figure 1.1). Rodinia probably contained all of the landmass at the time, which was about 75% of the continental landmass present today. Rodinia broke up about 750 million years ago. The geological evidence for this breakup includes large lava flows that are found where continental rifting took place. Seafloor spreading eventually started and created the oceans between the continents. The breakup of Rodinia may have triggered Snowball Earth around 700 million years ago. "
the breakup of rodinia may have triggered snowball earth.,(A) True (B) False,A,"By the end of the Archean, about 2.5 billion years ago, plate tectonics processes were completely recognizable. Small Proterozoic continents known as microcontinents collided to create supercontinents, which resulted in the uplift of massive mountain ranges. The history of the North American craton is an example of what generally happened to the cratons during the Precambrian. As the craton drifted, it collided with microcontinents and oceanic island arcs, which were added to the continents. Convergence was especially active between 1.5 and 1.0 billion years ago. These lands came together to create the continent of Laurentia. About 1.1 billion years ago, Laurentia became part of the supercontinent Rodinia (Figure 1.1). Rodinia probably contained all of the landmass at the time, which was about 75% of the continental landmass present today. Rodinia broke up about 750 million years ago. The geological evidence for this breakup includes large lava flows that are found where continental rifting took place. Seafloor spreading eventually started and created the oceans between the continents. The breakup of Rodinia may have triggered Snowball Earth around 700 million years ago. "
precambrian plate tectonic processes after about 2 billion years after earth formed were,(A) More like plate tectonics on Venus than on the modern Earth (B) More like plate tectonics on the Moon than on the modern Earth (C) Similar to modern plate tectonics (D) Much faster than modern plate tectonics,C,"By the end of the Archean, about 2.5 billion years ago, plate tectonics processes were completely recognizable. Small Proterozoic continents known as microcontinents collided to create supercontinents, which resulted in the uplift of massive mountain ranges. The history of the North American craton is an example of what generally happened to the cratons during the Precambrian. As the craton drifted, it collided with microcontinents and oceanic island arcs, which were added to the continents. Convergence was especially active between 1.5 and 1.0 billion years ago. These lands came together to create the continent of Laurentia. About 1.1 billion years ago, Laurentia became part of the supercontinent Rodinia (Figure 1.1). Rodinia probably contained all of the landmass at the time, which was about 75% of the continental landmass present today. Rodinia broke up about 750 million years ago. The geological evidence for this breakup includes large lava flows that are found where continental rifting took place. Seafloor spreading eventually started and created the oceans between the continents. The breakup of Rodinia may have triggered Snowball Earth around 700 million years ago. "
only about 25% of the continental landmass present today was part of rodinia.,(A) True (B) False,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
the supercontinent rodinia contained all of the continents on earth before 2 billion years ago.,(A) True (B) False,B,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
the supercontinent of rodinia was complete when laurentia collided with rodinia.,(A) True (B) False,A,"There are times in Earth history when all of the continents came together to form a supercontinent. Supercontinents come together and then break apart. Pangaea was the last supercontinent on Earth, but it was not the first. The supercontinent before Pangaea is called Rodinia. Rodinia contained about 75% of the continental landmass that is present today. The supercontinent came together about 1.1 billion years ago. Rodinia was not the first supercontinent either. Scientists think that three supercontinents came before Rodina, making five so far in Earth history. "
"after rodinia broke apart, oceans formed between the continents by the process",(A) Seafloor spreading (B) Subduction (C) Mountain building (D) Continental rifting,A,"At the end of the Paleozoic there was one continent and one ocean. When Pangaea began to break apart about 180 million years ago, the Panthalassa Ocean separated into the individual but interconnected oceans that we see today on Earth. The Atlantic Ocean basin formed as Pangaea split apart. The seafloor spreading that pushed Africa and South America apart is continuing to enlarge the Atlantic Ocean (Figure 1.1). As the continents moved apart there was an intense period of plate tectonic activity. Seafloor spreading was so vig- orous that the mid-ocean ridge buoyed upwards and displaced so much water that there was a marine transgression. Later in the Mesozoic those seas regressed and then transgressed again. "
this country is currently the largest producer of hazardous waste.,(A) China (B) United States (C) Europe (D) Australia,B,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
the government must oversee the superfund act because bo other organization is big enough to direct large corporations.,(A) True (B) False,A,"Love Canal opened peoples eyes to toxic waste burial. They realized there must be other Love Canals all over the country. Thousands of contaminated sites were found. The Superfund Act was passed in 1980. The law required that money be set aside for cleanup of toxic waste sites, like the Elizabeth Copper Mine in Vermont (see the far-right image in Figure 19.9). The law also required safer disposal of hazardous waste in the future. "
the resource conservation and recovery act of 1976 requires,(A) Companies to keep track of hazardous material produced (B) Companies to keep track of hazardous waste disposed (C) That workers must be protected from hazardous materials (D) All of the above,A,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
which of these is not hazardous?,(A) Pesticides (B) Batteries (C) Vinegar (D) Gasoline,C,"Hazardous waste is any waste material that is dangerous to human health or that degrades the environment. Haz- ardous waste includes substances that are: 1. 2. 3. 4. Toxic: causes serious harm or death, or is poisonous. Chemically active: causes dangerous or unwanted chemical reactions, such as explosions. Corrosive: destroys other things by chemical reactions. Flammable: easily catches fire and may send dangerous smoke into the air. All sorts of materials are hazardous wastes and there are many sources. Many people have substances that could become hazardous wastes in their homes. Several cleaning and gardening chemicals are hazardous if not used properly. These include chemicals like drain cleaners and pesticides that are toxic to humans and many other creatures. While these chemicals are fine if they are stored and used properly, if they are used or disposed of improperly, they may become hazardous wastes. Others sources of hazardous waste are shown in Table 1.1. Type of Hazardous Waste Chemicals from the automobile in- dustry Example Gasoline, used motor oil, battery acid, brake fluid Batteries Car batteries, household batteries Medical wastes Dry cleaning chemicals Surgical gloves, wastes contami- nated with body fluids such as blood, x-ray equipment Paints, paint thinners, paint strip- pers, wood stains Many various chemicals Agricultural chemicals Pesticides, herbicides, fertilizers Paints Why it is Hazardous Toxic to humans and other organ- isms; often chemically active; often flammable. Contain toxic chemicals; are often corrosive. Toxic to humans and other organ- isms; may be chemically active. Toxic; flammable. Toxic; many cause cancer in hu- mans. Toxic to humans; can harm other organism; pollute soils and water. Click image to the left or use the URL below. URL: "
it is okay to dispose hazardous material down the drain.,(A) True (B) False,B,"Thanks to the lessons of Love Canal, the U.S. now has laws requiring the safe disposal of hazardous waste. Companies must ensure that hazardous waste is not allowed to enter the environment in dangerous amounts. They must also protect their workers from hazardous materials. For example, they must provide employees with the proper safety gear and training (see Figure 19.10). "
china produces a tremendous amount of hazardous waste because,(A) The Chinese people have the highest standard of living on average (B) The Chinese produce many products for the developed nations (C) The Chinese use production standards that are so high they create toxic waste (D) None of these,B,"Nations that have more industry produce more hazardous waste. Currently, the United States is the worlds largest producer of hazardous wastes, but China, which produces so many products for the developed world, may soon take over the number-one spot. Countries with more industry produce more hazardous wastes than those with little industry. Problems with haz- ardous wastes and their disposal became obvious sooner in the developed world than in the developing world. As a result, many developed nations, including the United States, have laws to help control hazardous waste disposal and to clean toxic sites. As mentioned in the ""Impacts of Hazardous Waste"" concept, the Superfund Act requires companies to clean up contaminated sites that are designated as Superfund sites (Figure 1.1). If a responsible party cannot be identified, because the company has gone out of business or its culpability cannot be proven, the federal government pays for the cleanup out of a trust fund with money put aside by the petroleum and chemical industries. As a result of the Superfund Act, companies today are more careful about how they deal with hazardous substances. Superfund sites are located all over the nation and many are waiting to be cleaned up. The Resource Conservation and Recovery Act of 1976 requires that companies keep track of any hazardous materials they produce. These materials must be disposed of using government guidelines and records must be kept to show the government that the wastes were disposed of safely. Workers must be protected from the hazardous materials. To some extent, individuals can control the production and disposal of hazardous wastes. We can choose to use materials that are not hazardous, such as using vinegar as a cleanser. At home, people can control the amount of pesticides that they use (or they can use organic methods of pest control). It is also necessary to dispose of hazardous materials properly by not pouring them over the land, down the drain or toilet, or into a sewer or trashcan. Click image to the left or use the URL below. URL: "
"new york, michigan and california are the only locations of superfund sites.",(A) True (B) False,B,"Love Canal opened peoples eyes to toxic waste burial. They realized there must be other Love Canals all over the country. Thousands of contaminated sites were found. The Superfund Act was passed in 1980. The law required that money be set aside for cleanup of toxic waste sites, like the Elizabeth Copper Mine in Vermont (see the far-right image in Figure 19.9). The law also required safer disposal of hazardous waste in the future. "
it is easier and cheaper to clean up a toxic waste site than to prevent the site from being contaminated in the first place.,(A) True (B) False,B,"Preventing groundwater contamination is much easier and cheaper than cleaning it. To clean groundwater, the water, as well as the rock and soil through which it travels, must be cleansed. Thoroughly cleaning an aquifer would require cleansing each pore within the soil or rock unit. For this reason, cleaning polluted groundwater is very costly, takes years, and is sometimes not technically feasible. If the toxic materials can be removed from the aquifer, disposing of them is another challenge. "
who oversees the cleanup a superfund site if the responsible party cannot?,(A) The state government (B) The federal government (C) The people who are most affected by the toxic waste (D) It will not be cleaned up,B,"In 1978, people were relocated to safe areas. The problem of Love Canal was instrumental in the passage of the the Superfund Act in 1980. This law requires companies to be responsible for hazardous chemicals that they put into the environment and to pay to clean up polluted sites, which can often cost hundreds of millions of dollars. Love Canal became a Superfund site in 1983 and as a result, several measures were taken to secure the toxic wastes. The land was capped so that water could not reach the waste, debris was cleaned from the nearby area, and contaminated soils were removed. "
what can individuals do to lessen the creation of toxic waste problems?,(A) Use materials that are not hazardous (B) Use small amounts of hazardous materials (C) Dispose of hazardous materials properly (D) All of these,D,"What can individuals do to protect water quality? Find approved recycling or disposal facilities for motor oil and household chemicals. Use lawn, garden, and farm chemicals sparingly and wisely. Repair automobile or boat engine leaks immediately. Keep litter, pet waste, leaves, and grass clippings out of street gutters and storm drains. Click image to the left or use the URL below. URL: "
sedimentary rocks are laid down,(A) Vertically (B) Diagonally (C) Horizontally (D) None of the above,C,"Sedimentary rocks follow certain rules. 1. Sedimentary rocks are formed with the oldest layers on the bottom and the youngest on top. 2. Sediments are deposited horizontally, so sedimentary rock layers are originally horizontal, as are some vol- canic rocks, such as ash falls. 3. Sedimentary rock layers that are not horizontal are deformed. Since sedimentary rocks follow these rules, they are useful for seeing the effects of stress on rocks. Sedimentary rocks that are not horizontal must have been deformed. You can trace the deformation a rock has experienced by seeing how it differs from its original horizontal, oldest- on-bottom position. This deformation produces geologic structures such as folds, joints, and faults that are caused by stresses. "
the classic location to see layer cake geology is,(A) The Grand Canyon (B) The Himalayas (C) Hawaii (D) The Central Valley,A,"A geologic map shows the different rocks that are exposed at the surface of a region. Rock units are shown in a color identified in a key. On the geologic map of the Grand Canyon, for example, different rock types are shown in different colors. Some people call the Grand Canyon layer cake geology because most of the rock units are in layers. Rock units show up on both sides of a stream valley. A geologic map looks very complicated in a region where rock layers have been folded, like the patterns in marble cake. Faults are seen on this geologic map cutting across rock layers. When rock layers are tilted, you will see stripes of each layer on the map. There are symbols on a geologic map that tell you which direction the rock layers slant, and often there is a cut away diagram, called a cross section, that shows what the rock layers look like below the surface. A large-scale geologic map will just show geologic provinces. They do not show the detail of individual rock layers. "
a lake fills with sediment and then is buried and the sediment is lithified into sedimentary rock. the first sediment to fall to the lakebed will be,(A) In the rocks that are on the top (B) Swept away by bottom currents (C) In rocks spread throughout the layers (D) In the rocks that are on the bottom,D,"Accumulated sediments harden into rock by lithification, as illustrated in the Figure 1.1. Two important steps are needed for sediments to lithify. 1. Sediments are squeezed together by the weight of overlying sediments on top of them. This is called com- paction. Cemented, non-organic sediments become clastic rocks. If organic material is included, they are bioclastic rocks. 2. Fluids fill in the spaces between the loose particles of sediment and crystallize to create a rock by cementation. The sediment size in clastic sedimentary rocks varies greatly (see Table in Sedimentary Rocks Classification). This cliff is made of sandstone. Sands were deposited and then lithified. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
some volcanic rock types are laid down horizontally.,(A) True (B) False,A,"Sediments were deposited in ancient seas in horizontal, or flat, layers. If sedimentary rock layers are tilted, they must have moved after they were deposited. "
"if a group of sedimentary rocks is lying diagonally, they",(A) Were laid down diagonally (B) Were laid down vertically (C) but were tilted (D) c Were laid down horizontally (E) but were tilted (F) d Were laid down randomly (G) but were tilted,C,"Sediments were deposited in ancient seas in horizontal, or flat, layers. If sedimentary rock layers are tilted, they must have moved after they were deposited. "
sedimentary rocks are useful for deciphering the geological history of an area.,(A) True (B) False,A,"Sedimentary rocks follow certain rules. 1. Sedimentary rocks are formed with the oldest layers on the bottom and the youngest on top. 2. Sediments are deposited horizontally, so sedimentary rock layers are originally horizontal, as are some vol- canic rocks, such as ash falls. 3. Sedimentary rock layers that are not horizontal are deformed. Since sedimentary rocks follow these rules, they are useful for seeing the effects of stress on rocks. Sedimentary rocks that are not horizontal must have been deformed. You can trace the deformation a rock has experienced by seeing how it differs from its original horizontal, oldest- on-bottom position. This deformation produces geologic structures such as folds, joints, and faults that are caused by stresses. "
the grand canyon is a favorite location for geologists because,(A) It has a tremendous amount of mineral resources (B) It exposes the geologic history of the region like a storybook (C) It is a fabulous site for fossils (D) All of the above,B,"Youre standing in the Grand Canyon and you see rocks like those in the Figure 1.1. Using the rules listed above, try to figure out the geologic history of the geologic column. The Grand Canyon is full mostly of sedimentary rocks, which are important for deciphering the geologic history of a region. In the Grand Canyon, the rock layers are exposed like a layer cake. Each layer is made of sediments that were deposited in a particular environment - perhaps a lake bed, shallow offshore region, or a sand dune. (a) The rocks of the Grand Canyon are like a layer cake. (b) A geologic column showing the rocks of the Grand Canyon. In this geologic column of the Grand Canyon, the sedimentary rocks of groups 3 through 6 are still horizontal. Group 2 rocks have been tilted. Group 1 rocks are not sedimentary. The oldest layers are on the bottom and youngest are on the top. The ways geologists figure out the geological history of an area will be explored more in the chapter Earth History. Click image to the left or use the URL below. URL: "
deformation can,(A) Tilt a group of horizontal sedimentary layers to another position (B) Produce geologic structures such as folds (C) Cause earthquakes (D) All of the above,D,"Rocks have three possible responses to increasing stress (illustrated in Figure 1.3): elastic deformation: the rock returns to its original shape when the stress is removed. plastic deformation: the rock does not return to its original shape when the stress is removed. fracture: the rock breaks. Under what conditions do you think a rock is more likely to fracture? Is it more likely to break deep within Earths crust or at the surface? What if the stress applied is sharp rather than gradual? At the Earths surface, rocks usually break quite quickly, but deeper in the crust, where temperatures and pressures are higher, rocks are more likely to deform plastically. Sudden stress, such as a hit with a hammer, is more likely to make a rock break. Stress applied over time often leads to plastic deformation. Click image to the left or use the URL below. URL: "
the rocks at the bottom of the grand canyon do not have layers. they are sedimentary rocks that were laid down vertically.,(A) True (B) False,B,"Youre standing in the Grand Canyon and you see rocks like those in the Figure 1.1. Using the rules listed above, try to figure out the geologic history of the geologic column. The Grand Canyon is full mostly of sedimentary rocks, which are important for deciphering the geologic history of a region. In the Grand Canyon, the rock layers are exposed like a layer cake. Each layer is made of sediments that were deposited in a particular environment - perhaps a lake bed, shallow offshore region, or a sand dune. (a) The rocks of the Grand Canyon are like a layer cake. (b) A geologic column showing the rocks of the Grand Canyon. In this geologic column of the Grand Canyon, the sedimentary rocks of groups 3 through 6 are still horizontal. Group 2 rocks have been tilted. Group 1 rocks are not sedimentary. The oldest layers are on the bottom and youngest are on the top. The ways geologists figure out the geological history of an area will be explored more in the chapter Earth History. Click image to the left or use the URL below. URL: "
fossils found in the top layer of sedimentary rocks are the oldest.,(A) True (B) False,B,"There are many layers of rock in the Earths surface. Newer layers form on top of the older layers; the deepest rock layers are the oldest. Therefore, you can tell how old a fossil is by observing in which layer of rock it was found. Evolution of the horse. Fossil evi- dence, depicted by the skeletal frag- ments, demonstrates evolutionary mile- stones in this process. Notice the 57 million year evolution of the horse leg bones and teeth. Especially obvious is the transformation of the leg bones from having four distinct digits to that of todays horse. The fossils and the order in which fossils appear is called the fossil record. The fossil record provides evidence for when organisms lived on Earth, how species evolved, and how some species have gone extinct. Geologists use a method called radiometric dating to determine the exact age of rocks and fossils in each layer of rock. This technique, which is possible because radioactive materials decay at a known rate, measures how much of the radioactive materials in each rock layer have broken down ( Figure 1.3). Radiometric dating has been used to determine that the oldest known rocks on Earth are between 4 and 5 billion years old. The oldest fossils are between 3 and 4 billion years old. Remember that during Darwins time, people believed the Earth was just about 6,000 years old. The fossil record proves that Earth is much older than people once thought. "
the principle of uniformitarianism states that processes operate,(A) In an unknowable manner (B) Randomly; past processes may or may not be similar to present processes (C) Differently in at present than they did in the past (D) The same way at present as they did in the past,D,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
the idea of uniformitarianism was recognized by,(A) Harry Hess (B) Alfred Wegener (C) James Hutton (D) Jacques Cousteau,C,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
a rock that is made of sand of roughly the same size probably formed in,(A) A sand dune (B) A deep sea environment (C) A coral reef environment (D) An ancient river,A,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
geologists can identify that wind changed direction in ancient sandstone from,(A) Ripple marks (B) Very fine layering (C) Cross bedding (D) Devil’s holes,C,"In the photo of the Mesquite sand dune in Death Valley National Park, California (Figure 1.2), we see that wind can cause cross-bedding in sand. Cross-bedding is due to changes in wind direction. There are also ripples caused by the wind waving over the surface of the dune. Since we can observe wind forming sand dunes with these patterns now, we have a good explanation for how the Navajo sandstone formed. The Navajo sandstone is a rock formed from ancient sand dunes in which wind direction changed from time to time. This is just one example of how geologists use observations they make today to unravel what happened in Earths past. Rocks formed from volcanoes, oceans, rivers, and many other features are deciphered by looking at the geological work those features do today. Click image to the left or use the URL below. URL: "
ripple marks are caused by sand slumping down a dune face.,(A) True (B) False,B,"In the photo of the Mesquite sand dune in Death Valley National Park, California (Figure 1.2), we see that wind can cause cross-bedding in sand. Cross-bedding is due to changes in wind direction. There are also ripples caused by the wind waving over the surface of the dune. Since we can observe wind forming sand dunes with these patterns now, we have a good explanation for how the Navajo sandstone formed. The Navajo sandstone is a rock formed from ancient sand dunes in which wind direction changed from time to time. This is just one example of how geologists use observations they make today to unravel what happened in Earths past. Rocks formed from volcanoes, oceans, rivers, and many other features are deciphered by looking at the geological work those features do today. Click image to the left or use the URL below. URL: "
without the principle of uniformitarianism geologists could not understand earth history.,(A) True (B) False,A,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
rocks can form in or on,(A) Volcanoes (B) Oceans (C) Rivers (D) All of the above,D,"Rocks are classified into three major groups according to how they form. These three types are described in more detail in other concepts in this chapter, but here is a summary. The Rock Cycle. Igneous rocks form from the cooling and hardening of molten magma in many different environments. The chemical composition of the magma and the rate at which it cools determine what rock forms. Igneous rocks can cool slowly beneath the surface or rapidly at the surface. These rocks are identified by their composition and texture. More than 700 different types of igneous rocks are known. Sedimentary rocks form by the compaction and cementing together of sediments, broken pieces of rock-like gravel, sand, silt, or clay. Those sediments can be formed from the weathering and erosion of preexisting rocks. Sedimentary rocks also include chemical precipitates, the solid materials left behind after a liquid evaporates. Metamorphic rocks form when the minerals in an existing rock are changed by heat or pressure below the surface. Click image to the left or use the URL below. URL: "
navajo sandstone formed from volcanic eruptions.,(A) True (B) False,B,"The outcrop in the Figure 1.1 is at Checkerboard Mesa in Zion National Park, Utah. It has a very interesting pattern on it. As a geology student you may ask: how did this rock form? If you poke at the rock and analyze its chemistry you will see that its made of sand. In fact, the rock formation is called the Navajo sandstone. But knowing that the rock is sandstone doesnt tell you how it formed. It would be hard to design an experiment to show how this rock formed. But we can make observations now and apply them to this rock that formed long ago. "
"if cross-bedded sandstone forms in dunes today, it probably formed in dunes in the ancient past.",(A) True (B) False,A,"In the photo of the Mesquite sand dune in Death Valley National Park, California (Figure 1.2), we see that wind can cause cross-bedding in sand. Cross-bedding is due to changes in wind direction. There are also ripples caused by the wind waving over the surface of the dune. Since we can observe wind forming sand dunes with these patterns now, we have a good explanation for how the Navajo sandstone formed. The Navajo sandstone is a rock formed from ancient sand dunes in which wind direction changed from time to time. This is just one example of how geologists use observations they make today to unravel what happened in Earths past. Rocks formed from volcanoes, oceans, rivers, and many other features are deciphered by looking at the geological work those features do today. Click image to the left or use the URL below. URL: "
the idea that the present is the key to the past is called the principle of geology.,(A) True (B) False,B,"James Hutton came up with this idea in the late 1700s. The present is the key to the past. He called this the principle of uniformitarianism. It is that if we can understand a geological process now and we find evidence of that same Checkerboard Mesa in Zion National Park, Utah. process in the past, then we can assume that the process operated the same way in the past. Hutton speculated that it has taken millions of years to shape the planet, and it is continuing to be changed. He said that there are slow, natural processes that changed, and continue to change, the planets landscape. For example, given enough time, a stream could erode a valley, or sediment could accumulate and form a new landform. Lets go back to that outcrop. What would cause sandstone to have layers that cross each other, a feature called cross-bedding? "
original horizontality is when true,(A) Sediments are deposited fairly flat (B) horizontal layers (C) b Sediments are deposited in continuous sheets that span across a body of water (D) c Sedimentary rocks are layered one on top of another by age (E) d All of the above,A,"Remember Nicholas Steno, who determined that fossils represented parts of once-living organisms? Steno also noticed that fossil seashells could be found in rocks and mountains far from any ocean. He wanted to explain how that could occur. Steno proposed that if a rock contained the fossils of marine animals, the rock formed from sediments that were deposited on the seafloor. These rocks were then uplifted to become mountains. This scenario led him to develop the principles that are discussed below. They are known as Stenos laws. Stenos laws are illustrated in Figure 1.1. Original horizontality: Sediments are deposited in fairly flat, horizontal layers. If a sedimentary rock is found tilted, the layer was tilted after it was formed. Lateral continuity: Sediments are deposited in continuous sheets that span the body of water that they are deposited in. When a valley cuts through sedimentary layers, it is assumed that the rocks on either side of the valley were originally continuous. Superposition: Sedimentary rocks are deposited one on top of another. The youngest layers are found at the top of the sequence, and the oldest layers are found at the bottom. (a) Original horizontality. (b) Lateral continuity. (c) Superposition. "
"according to nicholas steno, if a rock at the top of a mountain contains fossils of marine animals, that rock formed in the sea and was uplifted into a mountain.",(A) True (B) False,A,"Remember Nicholas Steno, who determined that fossils represented parts of once-living organisms? Steno also noticed that fossil seashells could be found in rocks and mountains far from any ocean. He wanted to explain how that could occur. Steno proposed that if a rock contained the fossils of marine animals, the rock formed from sediments that were deposited on the seafloor. These rocks were then uplifted to become mountains. This scenario led him to develop the principles that are discussed below. They are known as Stenos laws. Stenos laws are illustrated in Figure 1.1. Original horizontality: Sediments are deposited in fairly flat, horizontal layers. If a sedimentary rock is found tilted, the layer was tilted after it was formed. Lateral continuity: Sediments are deposited in continuous sheets that span the body of water that they are deposited in. When a valley cuts through sedimentary layers, it is assumed that the rocks on either side of the valley were originally continuous. Superposition: Sedimentary rocks are deposited one on top of another. The youngest layers are found at the top of the sequence, and the oldest layers are found at the bottom. (a) Original horizontality. (b) Lateral continuity. (c) Superposition. "
superpostion is when _______________________.,(A) Sediments are deposited fairly flat (B) horizontal layers (C) b Sediments are deposited in continuous sheets that span across a body of water (D) c Sedimentary rocks are layered one on top of another by age (E) d All of the above,C,"Superposition refers to the position of rock layers and their relative ages. Relative age means age in comparison with other rocks, either younger or older. The relative ages of rocks are important for understanding Earths history. New rock layers are always deposited on top of existing rock layers. Therefore, deeper layers must be older than layers closer to the surface. This is the law of superposition. You can see an example in Figure 11.7. "
the oldest rocks are found ____________________ of a sequence.,(A) At the top (B) In the middle (C) At the bottom (D) None of the above,C,"By combining magnetic polarity data from rocks on land and on the seafloor with radiometric age dating and fossil ages, scientists came up with a time scale for the magnetic reversals. The first four magnetic periods are: Brunhes normal - present to 730,000 years ago. Matuyama reverse - 730,000 years ago to 2.48 million years ago. Gauss normal - 2.48 to 3.4 million years ago. Gilbert reverse - 3.4 to 5.3 million years ago. The scientists noticed that the rocks got older with distance from the mid-ocean ridges. The youngest rocks were located at the ridge crest and the oldest rocks were located the farthest away, abutting continents. Scientists also noticed that the characteristics of the rocks and sediments changed with distance from the ridge axis as seen in the Table 1.1. Rock ages At ridge axis With distance from axis youngest becomes older Sediment thickness none becomes thicker Crust thickness Heat flow thinnest becomes thicker hottest becomes cooler Away from the ridge crest, sediment becomes older and thicker, and the seafloor becomes thicker. Heat flow, which indicates the warmth of a region, is highest at the ridge crest. The oldest seafloor is near the edges of continents or deep sea trenches and is less than 180 million years old (Figure something was happening to the older seafloor. Seafloor is youngest at the mid-ocean ridges and becomes progressively older with distance from the ridge. How can you explain the observations that scientists have made in the oceans? Why is rock younger at the ridge and oldest at the farthest points from the ridge? The scientists suggested that seafloor was being created at the ridge. Since the planet is not getting larger, they suggested that it is destroyed in a relatively short amount of geologic time. Click image to the left or use the URL below. URL: "
if the same sedimentary rock layer is found on either side of a valley,(A) The rocks on one side were moved across by earthquake action (B) The rock formed in the same environment and the valley was cut into the rock later (C) The rocks look the same (D) but they are two separate rocks formed in two separate ways (E) d There is something wrong (F) because this could never happen in nature,B,"Rock layers extend laterally, or out to the sides. They may cover very broad areas, especially if they formed at the bottom of ancient seas. Erosion may have worn away some of the rock, but layers on either side of eroded areas will still match up. Look at the Grand Canyon in Figure 11.8. Its a good example of lateral continuity. You can clearly see the same rock layers on opposite sides of the canyon. The matching rock layers were deposited at the same time, so they are the same age. "
which of the following is true about fossils?,(A) Some fossils types are never found together (B) Younger fossils display more modern features than older fossils (C) Fossil species with features that change distinctly and rapidly can be used to determine ages precisely (D) All of these,D,"Fossils are the preserved remains or traces of organisms that lived during earlier ages. Remains that become fossils are generally the hard parts of organismsmainly bones, teeth, or shells. Traces include any evidence of life, such as footprints like the dinosaur footprint in Figure 7.7. Fossils are like a window into the past. They provide direct evidence of what life was like long ago. A scientist who studies fossils to learn about the evolution of living things is called a paleontologist. "
fossils of human ancestors have been found with dinosaur fossils.,(A) True (B) False,B,"That life on Earth has changed over time is well illustrated by the fossil record. Fossils in relatively young rocks resemble animals and plants that are living today. In general, fossils in older rocks are less similar to modern organisms. We would know very little about the organisms that came before us if there were no fossils. Modern technology has allowed scientists to reconstruct images and learn about the biology of extinct animals like dinosaurs! Click image to the left for more content. "
"if an igneous dike cuts across metamorphic rock layers,",(A) We know that the metamorphic rocks are older (B) We know that the igneous rock dike is older (C) We cannot know which formed first (D) We know that they both formed at the same time,A,"Rock layers may have another rock cutting across them, like the igneous rock in Figure 11.9. Which rock is older? To determine this, we use the law of cross-cutting relationships. The cut rock layers are older than the rock that cuts across them. "
"in the grand canyon,",(A) The horizontal rock layers are sedimentary rocks that were deposited horizontally (B) The rock layers are found separated by valleys so they are laterally continuous (C) The Colorado River is younger than the rocks it cuts across (D) All of the above are true,D,"The Grand Canyon provides an excellent illustration of the principles above. The many horizontal layers of sedi- mentary rock illustrate the principle of original horizontality (Figure 1.3). The youngest rock layers are at the top and the oldest are at the bottom, which is described by the law of superposition. Distinctive rock layers, such as the Kaibab Limestone, are matched across the broad expanse of the canyon. These rock layers were once connected, as stated by the rule of lateral continuity. The Colorado River cuts through all the layers of rock to form the canyon. Based on the principle of cross- cutting relationships, the river must be younger than all of the rock layers that it cuts through. "
feathered dinosaurs preceded birds in the fossil record.,(A) True (B) False,B,"The Triassic mass extinction gave dinosaurs the opportunity to really flourish during the Jurassic Period. Thats why this period is called the golden age of dinosaurs. The earliest birds also evolved during the Jurassic from dinosaur ancestors. In addition, all the major groups of mammals appeared. Flowering plants also appeared for the first time. New insects evolved to pollinate them. The continents continued to move apart. "
this drives the water cycle.,(A) The ocean (B) The sun (C) The core (D) The air,B,"The Sun, many millions of kilometers away, provides the energy that drives the water cycle. Our nearest star directly impacts the water cycle by supplying the energy needed for evaporation. "
when water changes from a liquid to a gas.,(A) Precipitation (B) Condensation (C) Evaporation (D) Hydration,C,A liquid can also change to a gas without boiling. This process is called evaporation. It occurs when particles at the exposed surface of a liquid absorb just enough energy to pull away from the liquid and escape into the air. This happens faster at warmer temperatures. Look at the puddle in Figure 4.21. It formed in a pothole during a rain shower. The puddle will eventually evaporate. It will evaporate faster if the sun comes out and heats the water than if the sky remains cloudy. 
"rain, sleet, hail, or snow are examples of this.",(A) Precipitation (B) Condensation (C) Evaporation (D) Hydration,A,"The most common precipitation comes from clouds. Rain or snow droplets grow as they ride air currents in a cloud and collect other droplets (Figure 1.2). They fall when they become heavy enough to escape from the rising air currents that hold them up in the cloud. One million cloud droplets will combine to make only one rain drop! If temperatures are cold, the droplet will hit the ground as snow. (a) Dew on a flower. (b) Hoar frost. (a) Rain falls from clouds when the temperature is fairly warm. (b) Snow storm in Helsinki, Finland. Other less common types of precipitation are sleet (Figure 1.3). Sleet is rain that becomes ice as it hits a layer of freezing air near the ground. If a frigid raindrop freezes on the frigid ground, it forms glaze. Hail forms in cumulonimbus clouds with strong updrafts. An ice particle travels until it finally becomes too heavy and it drops. (a) Sleet. (b) Glaze. (c) Hail. This large hail stone is about 6 cm (2.5 inches) in diameter. Click image to the left or use the URL below. URL: "
which of these is an example of sublimation?,(A) Ice changing to water (B) Water changing to ice (C) Water vapor changing to a cloud (D) Snow changing into a gas,D,"The opposite of sublimation is deposition. This is the process in which a gas changes directly to a solid without going through the liquid state. It occurs when gas particles become very cold. For example, when water vapor in the air contacts a very cold windowpane, the water vapor may change to tiny ice crystals on the glass. The ice crystals are called frost. You can see an example in Figure 4.24. "
plants do this process where water vapor can go into the air through the leaves.,(A) Sublimation (B) Condensation (C) Transpiration (D) Precipitation,C,"Plants and animals depend on water to live. They also play a role in the water cycle. Plants take up water from the soil and release large amounts of water vapor into the air through their leaves (Figure 1.3), a process known as transpiration. "
another name for the water cycle is this.,(A) Atmospheric cycle (B) Lithospheric cycle (C) Biospheric cycle (D) Hydrological cycle,D,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
the only reason plants can grow in arid regions is that there is a lot of water trapped in the soil.,(A) True (B) False,B,"Plants that live in extremely dry environments have the opposite problem: how to get and keep water. Plants that are adapted to very dry environments are called xerophytes. Their adaptations may help them increase water intake, decrease water loss, or store water when its available. The saguaro cactus pictured in Figure 10.27 has adapted in all three ways. When it was still a very small plant, just a few inches high, its shallow roots already reached out as much as 2 meters (7 feet) from the base of the stem. By now, its root system is much more widespread. It allows the cactus to gather as much moisture as possible from rare rainfalls. The saguaro doesnt have any leaves to lose water by transpiration. It also has a large, barrel-shaped stem that can store a lot of water. Thorns protect the stem from thirsty animals that might try to get at the water inside. "
when atmospheric temperature rises sea level __________ because __________.,(A) Rises; ice caps and glaciers melt (B) Falls; ice caps and glaciers grow (C) Rises; ice caps and glaciers grow (D) Falls; ice caps and glaciers melt,A,"As greenhouse gases increase, changes will be more extreme. Oceans will become more acidic, making it more difficult for creatures with carbonate shells to grow, and that includes coral reefs. A study monitoring ocean acidity in the Pacific Northwest found ocean acidity increasing ten times faster than expected and 10% to 20% of shellfish (mussels) being replaced by acid-tolerant algae. Plant and animal species seeking cooler temperatures will need to move poleward 100 to 150 km (60 to 90 miles) or upward 150 m (500 feet) for each 1.0o C (8o F) rise in global temperature. There will be a tremendous loss of biodiversity because forest species cant migrate that rapidly. Biologists have already documented the extinction of high-altitude species that have nowhere higher to go. Decreased snow packs, shrinking glaciers, and the earlier arrival of spring will all lessen the amount of water available in some regions of the world, including the western United States and much of Asia. Ice will continue to melt and sea level is predicted to rise 18 to 97 cm (7 to 38 inches) by 2100 (Figure 1.3). An increase this large will gradually flood coastal regions, where about one-third of the worlds population lives, forcing billions of people to move inland. Sea ice thickness around the North Pole has been decreasing in recent decades and will continue to decrease in the com- ing decades. Weather will become more extreme, with more frequent and more intense heat waves and droughts. Some modelers predict that the midwestern United States will become too dry to support agriculture and that Canada will become the new breadbasket. In all, about 10% to 50% of current cropland worldwide may become unusable if CO2 doubles. You may notice that the numerical predictions above contain wide ranges. Sea level, for example, is expected to rise somewhere between 18 and 97 cm  quite a wide range. What is the reason for this uncertainty? It is partly because scientists cannot predict exactly how the Earth will respond to increased levels of greenhouses gases. How quickly greenhouse gases continue to build up in the atmosphere depends in part on the choices we make. An important question people ask is this: Are the increases in global temperature natural? In other words, can natural variations in temperature account for the increase in temperature that we see? The answer is no. Changes in the Suns irradiance, El Nio and La Nia cycles, natural changes in greenhouse gas, and other atmospheric gases cannot account for the increase in temperature that has already happened in the past decades. Along with the rest of the worlds oceans, San Francisco Bay is rising. Changes are happening slowly in the coastal arena of the San Francisco Bay Area and even the most optimistic estimates about how high and how quickly this rise will occur indicate potentially huge problems for the region. Click image to the left or use the URL below. URL: "
water can be stored for future use in snow and ice.,(A) True (B) False,A,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
"as far back as the roman empire, humans diverted water to suit their own needs.",(A) True (B) False,A,"People also depend on water as a natural resource. Not content to get water directly from streams or ponds, humans create canals, aqueducts, dams, and wells to collect water and direct it to where they want it (Figure 1.4). Clouds form above the Amazon Rainfor- est even in the dry season because of moisture from plant transpiration. Pont du Gard in France is an ancient aqueduct and bridge that was part of of a well-developed system that supplied wa- ter around the Roman empire. Click image to the left or use the URL below. URL: "
epa stands for,(A) Environmental Police Agency (B) Electric Protection Agency (C) Environmental Protection Agency (D) Engenious Policing Agency,C,"Keeping water from becoming polluted often requires laws to be sure that people and companies behave responsibly. In the United States, the Clean Water Act gives the Environmental Protection Agency (EPA) the authority to set standards for water quality for industry, agriculture, and domestic uses. The law gives the EPA the authority to reduce the discharge of pollution into waterways, finance wastewater treatment plants, and manage runoff. Since its passage in 1972, more wastewater treatment plants have been constructed and the release of industrial waste into the water supply is better controlled. Scientists control water pollution by sam- pling the water and studying the pollutants that are in the water. The United Nations and other international groups are working to improve global water quality standards by pro- viding the technology for treating water. These organizations also educate people in how to protect and improve the quality of the water they use (Figure 1.1). Click image to the left or use the URL below. URL: "
"water quality standards are set by __________, in accordance with the __________ act.",(A) The EPA; Clean Water (B) State governments; Clean Environment (C) The federal government; Environmental Protection (D) Clean Water Association; Water Quality,A,"Keeping water from becoming polluted often requires laws to be sure that people and companies behave responsibly. In the United States, the Clean Water Act gives the Environmental Protection Agency (EPA) the authority to set standards for water quality for industry, agriculture, and domestic uses. The law gives the EPA the authority to reduce the discharge of pollution into waterways, finance wastewater treatment plants, and manage runoff. Since its passage in 1972, more wastewater treatment plants have been constructed and the release of industrial waste into the water supply is better controlled. Scientists control water pollution by sam- pling the water and studying the pollutants that are in the water. The United Nations and other international groups are working to improve global water quality standards by pro- viding the technology for treating water. These organizations also educate people in how to protect and improve the quality of the water they use (Figure 1.1). Click image to the left or use the URL below. URL: "
the first step of treating wastewater is,(A) De-oxidizing the wastes (B) Chemically purifying the water to be drinking water (C) Exposing the water to ultraviolet radiation for cleanliness (D) Removing the large and small particles,D,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
which of these is a wastewater contaminant?,(A) Suspended solids (B) Dissolved inorganic compounds (C) Bacteria (D) All of the above,D,"Wastewater from cities and towns contains many different contaminants from many different homes, businesses, and industries (Figure 1.1). Contaminants come from: Sewage disposal (some sewage is inadequately treated or untreated). Storm drains. Septic tanks (sewage from homes). Boats that dump sewage. Yard runoff (fertilizer and herbicide waste). Large numbers of sewage spills into San Francisco Bay are forcing cities, water agencies and the public to take a closer look at wastewater and its impacts on the health of the bay. QUEST investigates the causes of the spills and whats being done to prevent them. Click image to the left or use the URL below. URL: "
some water is purified enough for spreading on grass and some water is purified enough for drinking.,(A) True (B) False,A,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
water purification produces useable water by removing _____________.,(A) Solids and particles (B) Bacteria (C) Sediments (D) A & B,B,"The goal of water treatment is to make water suitable for such uses as drinking, medicine, agriculture, and industrial processes. People living in developed countries suffer from few waterborne diseases and illness, because they have extensive water treatment systems to collect, treat, and redeliver clean water. Many underdeveloped nations have few or no water treatment facilities. Wastewater contains hundreds of contaminants, such as suspended solids, oxygen-demanding materials, dissolved inorganic compounds, and harmful bacteria. In a wastewater treatment plant, multiple processes must be used to produce usable water: Sewage treatment removes contaminants, such as solids and particles, from sewage. Water purification produces drinking water by removing bacteria, algae, viruses, fungi, unpleasant elements such as iron and sulfur, and man-made chemical pollutants. The treatment method used depends on the kind of wastewater being treated and the desired end result. Wastewater is treated using a series of steps, each of which produces water with fewer contaminants. "
repairing automobile or boat engine leaks right away helps to protect water.,(A) True (B) False,A,"What can individuals do to protect water quality? Find approved recycling or disposal facilities for motor oil and household chemicals. Use lawn, garden, and farm chemicals sparingly and wisely. Repair automobile or boat engine leaks immediately. Keep litter, pet waste, leaves, and grass clippings out of street gutters and storm drains. Click image to the left or use the URL below. URL: "
"when you take your dog to the park, you should leave its waste in place to act as fertilizer for nearby plants.",(A) True (B) False,B,"Government policies and laws are needed to protect biodiversity. Such actions have been shown to work in the past. For example, peregrine falcons made an incredible recovery after laws were passed banning the use of DDT. Individuals can also play a role in protecting biodiversity. What can you do? Here are a few suggestions: Start a compost pile to recycle organic wastes. Use the compost to enrich yard and garden soil. It will reduce the need for chemical fertilizers and added water. Make your backyard welcoming to native wildlife. Plant native plants that will provide food and shelter for native animals such as birds and amphibians. Add a water source, such as a fountain or bird bath. Avoid the introduction of exotic species to local habitats. Avoid the use of herbicides and pesticides. In addition to killing garden weeds and pests, they may harm native organisms, such as wildflowers, honey bees, and song birds. Conserve natural resources, including energy resources. Always reduce, reuse, or recycle. Learn more about biodiversity and how to protect it. Then pass on what you learn to others. "
"to keep water from being polluted, individuals can",(A) Be sure storm drains are kept clean (B) Repair engine leaks immediately (C) Use chemicals in the house and yard as little as possible and always following directions (D) All of these,D,Water pollution can be reduced in two ways: Keep the water from becoming polluted. Clean water that is already polluted. 
keeping pollutants from getting into the water system is better than cleaning the water up after it is polluted.,(A) True (B) False,A,Water pollution can be reduced in two ways: Keep the water from becoming polluted. Clean water that is already polluted. 
radioactive isotopes are __________ and spontaneously change by ____________.,(A) Unstable; Adding or subtracting particles (B) Unstable; keeping their particles (C) Stable; Gaining or losing particles (D) Stable; keeping their particles,A,"Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). "
radioactive decay of an isotope leads to the formation of a ____________ product.,(A) Unstable daughter (B) Stable parent (C) Unstable parent (D) Stable daughter,D,"Some isotopes are radioactive; radioactive isotopes are unstable and spontaneously change by gaining or losing particles. Two types of radioactive decay are relevant to dating Earth materials (Table 1.1): Particle Alpha Composition 2 protons, 2 neutrons Beta 1 electron Effect on Nucleus The nucleus contains two fewer protons and two fewer neutrons. One neutron decays to form a pro- ton and an electron. The electron is emitted. The radioactive decay of a parent isotope (the original element) leads to the formation of stable daughter product, also known as daughter isotope. As time passes, the number of parent isotopes decreases and the number of daughter isotopes increases (Figure 1.1). "
if a radioactive isotope loses an alpha particle its charge changes by,(A) The loss of two negatives (B) The loss of two positives (C) The addition of one positive (D) The loss of one negative,B,"Both alpha and beta decay change the number of protons in an atoms nucleus, thereby changing the atom to a different element. In alpha decay, the nucleus loses two protons. In beta decay, the nucleus either loses a proton or gains a proton. In gamma decay, no change in proton number occurs, so the atom does not become a different element. Q: If the radioactive element polonium (Po) undergoes alpha decay, what element does it become? A: From the periodic table, the atomic number of polonium is 84, so it has 84 protons. If it loses two protons through alpha decay, it will have 82 protons. Atoms with 82 protons are the element lead (Pb). "
"if two half-lives have passed, this percent of the parent isotope remains.",(A) 100% (B) 50% (C) 25% (D) 125%,C,"Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL: "
"if 75% of the daughter is produced, this many half-lives have passed.",(A) 0 (B) 1 (C) 2 (D) 3,C,"Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL: "
a half life is the time it takes for half of the parent isotopes to change into daughter isotopes.,(A) True (B) False,A,"Radioactive materials decay at known rates, measured as a unit called half-life. The half-life of a radioactive substance is the amount of time it takes for half of the parent atoms to decay. This is how the material decays over time (see Table 1.2). No. of half lives passed 0 1 2 3 4 5 6 7 8 Percent parent remaining 100 50 25 12.5 6.25 3.125 1.563 0.781 0.391 Percent daughter produced 0 50 75 87.5 93.75 96.875 98.437 99.219 99.609 Pretend you find a rock with 3.125% parent atoms and 96.875% daughter atoms. How many half lives have passed? If the half-life of the parent isotope is 1 year, then how old is the rock? The decay of radioactive materials can be shown with a graph (Figure 1.2). Notice how it doesnt take too many half lives before there is very little parent remaining and most of the isotopes are daughter isotopes. This limits how many half lives can pass before a radioactive element is no longer useful for Decay of an imaginary radioactive sub- stance with a half-life of one year. dating materials. Fortunately, different isotopes have very different half lives. Click image to the left or use the URL below. URL: "
radiometric decay,(A) Is exponential (B) Is constant (C) Plateaus (D) None of the above,A,The rate of decay of unstable isotopes can be used to estimate the absolute ages of fossils and rocks. This type of dating is called radiometric dating. 
this team of physicists discovered the spontaneous emission of particles that they called radioactivity.,(A) Steno and Sutton (B) Pierre and Marie Curie (C) Watson and Crick (D) Darwin and Wallace,B,"Radioactivity was discovered in 1896 by a French physicist named Antoine Henri Becquerel, who is pictured 1.1. Becquerel was experimenting with uranium, which was known to glow after being exposed to sunlight. Becquerel wanted to see if the glow was caused by rays of energy, like rays of light or X-rays. He placed a bit of uranium on a photographic plate after exposing the uranium to sunlight. The plate was similar to the film that is used today to take X-rays, and Becquerel expected the uranium to leave an image on the plate. The next day, there was an image on the plate, just as Becquerel expected. This meant that uranium gives off rays after being exposed to sunlight. Becquerel was a good scientist, so he wanted to repeat his experiment to confirm his results. He placed more uranium on another photographic plate. However, the day had turned cloudy, so he tucked the plate and uranium in a drawer to try again another day. He wasnt expecting the uranium to leave an image on the plate without first being exposed to sunlight. To his surprise, there was an image on the plate in the drawer the next day. Becquerel had discovered that uranium gives off rays of energy on its own. He had discovered radioactivity, for which he received a Nobel prize. Another scientist, who worked with Becquerel, actually came up with the term radioactivity. The other scientist was the French chemist Marie Curie. She went on to discover the radioactive elements polonium and radium. She won two Nobel Prizes for her discoveries. "
a radioactive isotope pair is only useful for as long as there is enough daughter to be able to count.,(A) True (B) False,B,"Atoms need a certain ratio of neutrons to protons to have a stable nucleus. Having too many or too few neutrons relative to protons results in an unstable, or radioactive, nucleus that will sooner or later break down to a more stable form. This process is called radioactive decay. Many isotopes have radioactive nuclei, and these isotopes are referred to as radioisotopes. When they decay, they release particles that may be harmful. This is why radioactive isotopes are dangerous and why working with them requires special suits for protection. The isotope of carbon known as carbon-14 is an example of a radioisotope. In contrast, the carbon isotopes called carbon-12 and carbon-13 are stable. "
radiometric dating is used to estimate the age of a material by,(A) Counting the amount of parent isotope (B) Counting the amount of daughter isotope (C) Knowing or calculating the half life of parent to daughter (D) All of these,D,Radiometric dating is the process of using the concentrations of radioactive substances and daughter products to estimate the age of a material. Different isotopes are used to date materials of different ages. Using more than one isotope helps scientists to check the accuracy of the ages that they calculate. 
radiometric dating only works for materials of these ages because,(A) Young materials; the amount of parent isotope gets too low to count (B) Old materials; the amount of daughter isotope gets too low to count (C) All ages; different isotope pairs have different half lives (D) None of these,C,"As youve learned, radiometric dating can only be done on certain materials. But these important numbers can still be used to get the ages of other materials! How would you do this? One way is to constrain a material that cannot be dated by one or more that can. For example, if sedimentary rock A is below volcanic rock B and the age of volcanic rock B is 2.0 million years, then you know that sedimentary rock A is older than 2.0 million years. If sedimentary rock A is above volcanic rock C and its age is 2.5 million years then you know that sedimentary rock A is between 2.0 and 2.5 million years. In this way, geologists can figure out the approximate ages of many different rock formations. "
radiometric dating uses the rate of decay of unstable isotopes to calculate the absolute ages of fossils and rocks.,(A) True (B) False,A,The rate of decay of unstable isotopes can be used to estimate the absolute ages of fossils and rocks. This type of dating is called radiometric dating. 
carbon-14 dating is used for dating human remains and artifacts because,(A) The half life is right for dating materials of those ages (B) Human fossils and materials earlier humans used often contain carbon (C) The method is useful for materials that are between 100 and 50 (D) 000 years old (E) d All of these,D,"The best-known method of radiometric dating is carbon-14 dating. A living thing takes in carbon-14 (along with stable carbon-12). As the carbon-14 decays, it is replaced with more carbon-14. After the organism dies, it stops taking in carbon. That includes carbon-14. The carbon-14 that is in its body continues to decay. So the organism contains less and less carbon-14 as time goes on. We can estimate the amount of carbon-14 that has decayed by measuring the amount of carbon-14 to carbon-12. We know how fast carbon-14 decays. With this information, we can tell how long ago the organism died. Carbon-14 has a relatively short half-life. It decays quickly compared to some other unstable isotopes. So carbon- 14 dating is useful for specimens younger than 50,000 years old. Thats a blink of an eye in geologic time. But radiocarbon dating is very useful for more recent events. One important use of radiocarbon is early human sites. Carbon-14 dating is also limited to the remains of once-living things. To date rocks, scientists use other radioactive isotopes. "
"carbon-14 decays to carbon-12 with a half-life of 5,730 years.",(A) True (B) False,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
carbon dating measures when the organism died because only then does,(A) Carbon -14 decay to carbon-12 (B) Carbon-14 decay to nitrogen-14 (C) Carbon-12 decay to carbon-14 (D) None of these,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
in potassium-argon dating,(A) Potassium-40 decays to argon-40 (B) The parent isotope as a half-life of 126 million years (C) The technique can be used only in organic materials (D) All of the above,A,"Potassium-40 decays to argon-40 with a half-life of 1.26 billion years. Argon is a gas so it can escape from molten magma, meaning that any argon that is found in an igneous crystal probably formed as a result of the decay of potassium-40. Measuring the ratio of potassium-40 to argon-40 yields a good estimate of the age of that crystal. Potassium is common in many minerals, such as feldspar, mica, and amphibole. With its half-life, the technique is used to date rocks from 100,000 years to over a billion years old. The technique has been useful for dating fairly young geological materials and deposits containing the bones of human ancestors. "
which is a limitation of radiometric dating?,(A) Radiometric dating can be done only on sedimentary rock and plant fossils (B) There must be carbon-12 in the material (C) Both the amount of parent and daughter must be measureable (D) All of the above,C,"Radiometric dating is a very useful tool for dating geological materials but it does have limits: 1. The material being dated must have measurable amounts of the parent and/or the daughter isotopes. Ideally, different radiometric techniques are used to date the same sample; if the calculated ages agree, they are thought to be accurate. 2. Radiometric dating is not very useful for determining the age of sedimentary rocks. To estimate the age of a sedimentary rock, geologists find nearby igneous rocks that can be dated and use relative dating to constrain the age of the sedimentary rock. "
potassium-argon and uranium-lead dating are useful for very young materials.,(A) True (B) False,B,"Potassium-40 decays to argon-40 with a half-life of 1.26 billion years. Argon is a gas so it can escape from molten magma, meaning that any argon that is found in an igneous crystal probably formed as a result of the decay of potassium-40. Measuring the ratio of potassium-40 to argon-40 yields a good estimate of the age of that crystal. Potassium is common in many minerals, such as feldspar, mica, and amphibole. With its half-life, the technique is used to date rocks from 100,000 years to over a billion years old. The technique has been useful for dating fairly young geological materials and deposits containing the bones of human ancestors. "
uranium-lead has been used to calculate the ages of zircon crystals that are 4.4 billion years old.,(A) True (B) False,A,"Two uranium isotopes are used for radiometric dating. Uranium-238 decays to lead-206 with a half-life of 4.47 billion years. Uranium-235 decays to form lead-207 with a half-life of 704 million years. Uranium-lead dating is usually performed on zircon crystals (Figure 1.2). When zircon forms in an igneous rock, the crystals readily accept atoms of uranium but reject atoms of lead. If any lead is found in a zircon crystal, it can be assumed that it was produced from the decay of uranium. Uranium-lead dating is useful for dating igneous rocks from 1 million years to around 4.6 billion years old. Zircon crystals from Australia are 4.4 billion years old, among the oldest rocks on the planet. "
which of these is not one of the six major pollutants regulated by the clean air act?,(A) Lead (B) Carbon Monoxide (C) Carbon dioxide (D) Ozone,C,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
a catalyst _______________ a chemical reaction.,(A) Speeds up (B) Slows down (C) Keeps constant (D) None of the above,A,"Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions. Catalysts are not reactants, but they help reactants come together so they can react. You can see one way this happens in the animation at the URL below. By helping reactants come together, a catalyst decreases the activation energy needed to start a chemical reaction. This speeds up the reaction. Living things depend on catalysts to speed up many chemical reactions inside their cells. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take billions of years without it! "
catalytic converters,(A) Break down nitrous oxides (B) carbon monoxide (C) and VOCs (D) b Break down pollutants the entire time the car is running (E) c Make the car more fuel efficient (F) d All of the above,A,"Some of the pollutants from fossil fuels can be filtered out of exhaust before it is released into the air. Other pollutants can be changed to harmless compounds before they are released. Two widely used technologies are scrubbers and catalytic converters. Scrubbers are used in factories and power plants. They remove particulates and waste gases from exhaust before it is released to the air. You can see how a scrubber works in Figure 22.15. Catalytic converters are used on motor vehicles. They break down pollutants in exhaust to non-toxic com- pounds. For example, they change nitrogen oxides to harmless nitrogen and oxygen gasses. "
"in a hybrid vehicle, the car is powered by",(A) An internal combustion engine (B) A battery that is charged by energy collected during braking (C) Electricity (D) A & B,D,"Reducing air pollution from vehicles can be done in a number of ways. Breaking down pollutants before they are released into the atmosphere. Motor vehicles emit less pollution than they once did because of catalytic converters (Figure 1.1). Catalytic converters contain a catalyst that speeds up chemical reactions and breaks down nitrous oxides, carbon monoxide, and VOCs. Catalytic converters only work when they are hot, so a lot of exhaust escapes as the car is warming up. Catalytic converters are placed on mod- ern cars in the United States. Making a vehicle more fuel efficient. Lighter, more streamlined vehicles need less energy. Hybrid vehicles have an electric motor and a rechargeable battery. The energy that would be lost during braking is funneled into charging the battery, which then can power the car. The internal combustion engine only takes over when power in the battery has run out. Hybrids can reduce auto emissions by 90% or more, but many models do not maximize the possible fuel efficiency of the vehicle. A plug-in hybrid is plugged into an electricity source when it is not in use, perhaps in a garage, to make sure that the battery is charged. Plug-in hybrids run for a longer time on electricity and so are less polluting than regular hybrids. Plug-in hybrids began to become available in 2010. Developing new technologies that do not use fossil fuels. Fueling a car with something other than a liquid organic-based fuel is difficult. A fuel cell converts chemical energy into electrical energy. Hydrogen fuel cells harness the energy released when hydrogen and oxygen come together to create water (Figure 1.2). Fuel cells are extremely efficient and they produce no pollutants. But developing fuel-cell technology has had many problems and no one knows when or if they will become practical. "
plug-in hybrids run for a longer time on electricity than regular hybrids.,(A) True (B) False,A,"Reducing air pollution from vehicles can be done in a number of ways. Breaking down pollutants before they are released into the atmosphere. Motor vehicles emit less pollution than they once did because of catalytic converters (Figure 1.1). Catalytic converters contain a catalyst that speeds up chemical reactions and breaks down nitrous oxides, carbon monoxide, and VOCs. Catalytic converters only work when they are hot, so a lot of exhaust escapes as the car is warming up. Catalytic converters are placed on mod- ern cars in the United States. Making a vehicle more fuel efficient. Lighter, more streamlined vehicles need less energy. Hybrid vehicles have an electric motor and a rechargeable battery. The energy that would be lost during braking is funneled into charging the battery, which then can power the car. The internal combustion engine only takes over when power in the battery has run out. Hybrids can reduce auto emissions by 90% or more, but many models do not maximize the possible fuel efficiency of the vehicle. A plug-in hybrid is plugged into an electricity source when it is not in use, perhaps in a garage, to make sure that the battery is charged. Plug-in hybrids run for a longer time on electricity and so are less polluting than regular hybrids. Plug-in hybrids began to become available in 2010. Developing new technologies that do not use fossil fuels. Fueling a car with something other than a liquid organic-based fuel is difficult. A fuel cell converts chemical energy into electrical energy. Hydrogen fuel cells harness the energy released when hydrogen and oxygen come together to create water (Figure 1.2). Fuel cells are extremely efficient and they produce no pollutants. But developing fuel-cell technology has had many problems and no one knows when or if they will become practical. "
a fuel cell converts chemical energy into _____________.,(A) Nuclear energy (B) Electrical energy (C) Solar energy (D) Hydrological Energy,B,"The energy to make the electricity comes from fuel. Fuel stores the energy and releases it when it is needed. Fuel is any material that can release energy in a chemical change. The food you eat acts as a fuel for your body. Gasoline and diesel fuel are fuels that provide the energy for most cars, trucks, and buses. But there are many different kinds of fuel. For fuel to be useful, its energy must be released in a way that can be controlled. "
"before being released from power plants, sulfur and nitric oxides",(A) Can be filtered out (B) Can be neutralized with bases (C) Can be broken down by catalysts (D) All of these,C,"Pollutants are removed from the exhaust streams of power plants and industrial plants before they enter the atmo- sphere. Particulates can be filtered out, and sulfur and nitric oxides can be broken down by catalysts. Removing these oxides reduces the pollutants that cause acid rain. Particles are relatively easy to remove from emissions by using motion or electricity to separate particles from the gases. Scrubbers remove particles and waste gases from exhaust using liquids or neutralizing materials (Figure 1.3). Gases, such as nitrogen oxides, can be broken down at very high temperatures. A hydrogen fuel-cell car looks like a gasoline-powered car. Scrubbers remove particles and waste gases from exhaust. "
these help to remove particles and waste gases from exhaust using liquids or neutralizing materials.,(A) Filters (B) Water treatment (C) Fans (D) Scrubbers,D,"Pollutants are removed from the exhaust streams of power plants and industrial plants before they enter the atmo- sphere. Particulates can be filtered out, and sulfur and nitric oxides can be broken down by catalysts. Removing these oxides reduces the pollutants that cause acid rain. Particles are relatively easy to remove from emissions by using motion or electricity to separate particles from the gases. Scrubbers remove particles and waste gases from exhaust using liquids or neutralizing materials (Figure 1.3). Gases, such as nitrogen oxides, can be broken down at very high temperatures. A hydrogen fuel-cell car looks like a gasoline-powered car. Scrubbers remove particles and waste gases from exhaust. "
"in gasification, this rock is heated to extremely high temperature to create syngas, which is then filtered.",(A) Granite (B) Coal (C) Limestone (D) Halite,B,"Gasification is a developing technology. In gasification, coal (rarely is another organic material used) is heated to extremely high temperatures to create syngas, which is then filtered. The energy goes on to drive a generator. Syngas releases about 80% less pollution than regular coal plants, and greenhouse gases are also lower. Clean coal plants do not need scrubbers or other pollution control devices. Although the technology is ready, clean coal plants are more expensive to construct and operate. Also, heating the coal to high enough temperatures uses a great deal of energy, so the technology is not energy efficient. In addition, large amounts of the greenhouse gas CO2 are still released with clean coal technology. Nonetheless, a few of these plants are operating in the United States and around the world. "
the six major pollutants have decreased by more than 50% since the clean air act of 1970 was implemented.,(A) True (B) False,A,"The Clean Air Act of 1970 and the amendments since then have done a great job in requiring people to clean up the air over the United States. Emissions of the six major pollutants regulated by the Clean Air Act  carbon monoxide, lead, nitrous oxides, ozone, sulfur dioxide, and particulates  have decreased by more than 50%. Cars, power plants, and factories individually release less pollution than they did in the mid-20th century. But there are many more cars, power plants, and factories. Many pollutants are still being released and some substances have been found to be pollutants that were not known to be pollutants in the past. There is still much work to be done to continue to clean up the air. "
the initial ban on cfcs was done based on,(A) Measurements of ozone levels by the British Antarctic Survey (B) Skin cancer levels in people who lived in the far northern and southern latitudes (C) Calculations of what would happen when CFCs reached the stratosphere (D) None of these,C,"One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone- destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs. "
cfcs stand for ___________.,(A) Chlorofluorocarbon (B) Chlorineflourinecarbon (C) Carbofluorochloro (D) Carbochlorflouro,A,"One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone- destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs. "
cfcs that reach the stratosphere release chlorine atoms that destroy _________.,(A) Carbon dioxide (B) Water (C) Oxygen (D) Ozone,D,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
the united states and most scandinavian countries banned ________ that were found to contain cfcs.,(A) Spray cans (B) Nail polish (C) Toilet Cleaner (D) Water,A,"One success story in reducing pollutants that harm the atmosphere concerns ozone-destroying chemicals. In 1973, scientists calculated that CFCs could reach the stratosphere and break apart. This would release chlorine atoms, which would then destroy ozone. Based only on their calculations, the United States and most Scandinavian countries banned CFCs in spray cans in 1978. More confirmation that CFCs break down ozone was needed before more was done to reduce production of ozone- destroying chemicals. In 1985, members of the British Antarctic Survey reported that a 50% reduction in the ozone layer had been found over Antarctica in the previous three springs. "
when chlorine breaks an ozone molecule it becomes,(A) One chlorine oxide molecule (B) One oxygen molecule and one oxygen atom (C) One oxygen molecule and two oxygen atoms (D) Three oxygen atoms,B,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
the montreal protocol,(A) Controls the way scientists monitor the ozone hole (B) Regulates the production and consumption of chemicals that destroy the ozone layer (C) Regulates the release of greenhouse gases (D) None of these,B,"The Montreal Protocol is a worldwide agreement on air pollution. It focuses on CFCs. It was signed by many countries in 1987. It controls almost 100 chemicals that can damage the ozone layer. Its aim is to return the ozone layer to its normal state. The Montreal Protocol has been effective in controlling CFCs. By 1995, few CFCs were still being used. But the ozone hole kept growing for several years after that because of the CFCs already in the atmosphere. It peaked in 2006. Since then, it has been somewhat smaller. "
the ozone hole will be back to its pre-1980 levels in one to two centuries.,(A) True (B) False,A,"Two years after the British Antarctic Survey report, the ""Montreal Protocol on Substances that Deplete the Ozone Layer"" was ratified by nations all over the world. The Montreal Protocol controls the production and consumption of 96 chemicals that damage the ozone layer (Figure 1.1). Hazardous substances are phased out first by developed nations and one decade later by developing nations. More hazardous substances are phased out more quickly. CFCs have been mostly phased out since 1995, although were used in developing nations until 2010. Some of the less hazardous substances will not be phased out until 2030. The Protocol also requires that wealthier nations donate money to develop technologies that will replace these chemicals. Ozone levels over North America decreased between 1974 and 2009. Models of the future predict what ozone levels would have been if CFCs were not being phased out. Warmer colors indicate more ozone. Since CFCs take many years to reach the stratosphere and can survive there a long time before they break down, the ozone hole will probably continue to grow for some time before it begins to shrink. The ozone layer will reach the same levels it had before 1980 around 2068 and 1950 levels in one or two centuries. "
"if damage to the ozone layer continues, the incidence of this disease will increase.",(A) Asthma (B) Diabetes (C) Asbestosis (D) Skin Cancer,D,"With less ozone in the stratosphere, more UV rays reach the ground. More UV rays increase skin cancer rates. Just a 1 percent loss of ozone causes a 5 percent increase in skin cancer. More UV rays also harm plants and phytoplankton. As a result, they produce less food. This may affect entire ecosystems. "
wealthier nations have donated money to develop technologies that will replace ozone destroying chemicals.,(A) True (B) False,A,"Two years after the British Antarctic Survey report, the ""Montreal Protocol on Substances that Deplete the Ozone Layer"" was ratified by nations all over the world. The Montreal Protocol controls the production and consumption of 96 chemicals that damage the ozone layer (Figure 1.1). Hazardous substances are phased out first by developed nations and one decade later by developing nations. More hazardous substances are phased out more quickly. CFCs have been mostly phased out since 1995, although were used in developing nations until 2010. Some of the less hazardous substances will not be phased out until 2030. The Protocol also requires that wealthier nations donate money to develop technologies that will replace these chemicals. Ozone levels over North America decreased between 1974 and 2009. Models of the future predict what ozone levels would have been if CFCs were not being phased out. Warmer colors indicate more ozone. Since CFCs take many years to reach the stratosphere and can survive there a long time before they break down, the ozone hole will probably continue to grow for some time before it begins to shrink. The ozone layer will reach the same levels it had before 1980 around 2068 and 1950 levels in one or two centuries. "
if cfcs had not been phased out the ozone layer would have,(A) Become thinner until it was virtually gone in 2060 (B) Disappeared by 2009 (C) Thinned at the same rate globally until it stabilized in about 2040 (D) None of these,A,"Two years after the British Antarctic Survey report, the ""Montreal Protocol on Substances that Deplete the Ozone Layer"" was ratified by nations all over the world. The Montreal Protocol controls the production and consumption of 96 chemicals that damage the ozone layer (Figure 1.1). Hazardous substances are phased out first by developed nations and one decade later by developing nations. More hazardous substances are phased out more quickly. CFCs have been mostly phased out since 1995, although were used in developing nations until 2010. Some of the less hazardous substances will not be phased out until 2030. The Protocol also requires that wealthier nations donate money to develop technologies that will replace these chemicals. Ozone levels over North America decreased between 1974 and 2009. Models of the future predict what ozone levels would have been if CFCs were not being phased out. Warmer colors indicate more ozone. Since CFCs take many years to reach the stratosphere and can survive there a long time before they break down, the ozone hole will probably continue to grow for some time before it begins to shrink. The ozone layer will reach the same levels it had before 1980 around 2068 and 1950 levels in one or two centuries. "
the planets in our solar system revolve around,(A) The Sun (B) The moon (C) Saturn (D) Earth,A,"The Sun and all the objects that are held by the Suns gravity are known as the solar system. These objects all revolve around the Sun. The ancient Greeks recognized five planets. These lights in the night sky changed their position against the background of stars. They appeared to wander. In fact, the word planet comes from a Greek word meaning wanderer. These objects were thought to be important, so they named them after gods from their mythology. The names for the planets Mercury, Venus, Mars, Jupiter, and Saturn came from the names of gods and a goddess. "
this 17th century scientist was persecuted for saying the earth orbits around the sun.,(A) Newton (B) Galileo (C) Ptolomy (D) Wegner,B,"Certainly no one today doubts that Earth orbits a star, the Sun. Photos taken from space, observations made by astronauts, and the fact that there has been so much successful space exploration that depends on understanding the structure of the solar system all confirm it. But in the early 17th century saying that Earth orbited the Sun rather than the reverse could get you tried for heresy, as it did Galileo. Lets explore the evolution of the idea that Earth orbits the Sun. "
the suns gravitational pull keeps the planets in orbit.,(A) True (B) False,A,"Planets are held in their orbits by the force of gravity. What would happen without gravity? Imagine that you are swinging a ball on a string in a circular motion. Now let go of the string. The ball will fly away from you in a straight line. It was the string pulling on the ball that kept the ball moving in a circle. The motion of a planet is very similar to the ball on a string. The force pulling the planet is the pull of gravity between the planet and the Sun. Every object is attracted to every other object by gravity. The force of gravity between two objects depends on the mass of the objects. It also depends on how far apart the objects are. When you are sitting next to your dog, there is a gravitational force between the two of you. That force is far too weak for you to notice. You can feel the force of gravity between you and Earth because Earth has a lot of mass. The force of gravity between the Sun and planets is also very large. This is because the Sun and the planets are very large objects. Gravity is great enough to hold the planets to the Sun even though the distances between them are enormous. Gravity also holds moons in orbit around planets. "
"in the geocentric model of the universe, everything in the heavens revolves around",(A) The moon (B) Saturn (C) The sun (D) Earth,D,"To an observer, Earth appears to be the center of the universe. That is what the ancient Greeks believed. This view is called the geocentric model, or ""Earth-centered"" model, of the universe. In the geocentric model, the sky, or heavens, are a set of spheres layered on top of one another. Each object in the sky is attached to a sphere and moves around Earth as that sphere rotates. From Earth outward, these spheres contain the Moon, Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. An outer sphere holds all the stars. Since the planets appear to move much faster than the stars, the Greeks placed them closer to Earth. The geocentric model explained why all the stars appear to rotate around Earth once per day. The model also explained why the planets move differently from the stars and from each other. One problem with the geocentric model is that some planets seem to move backwards (in retrograde) instead of in their usual forward motion around Earth. Around 150 A.D. the astronomer Ptolemy resolved this problem by using a system of circles to describe the motion of planets (Figure 1.1). In Ptolemys system, a planet moves in a small circle, called an epicycle. This circle moves around Earth in a larger circle, called a deferent. Ptolemys version of the geocentric model worked so well that it remained the accepted model of the universe for more than a thousand years. "
the planets appear to move slower than the stars.,(A) True (B) False,B,"The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD. "
ptolomys system worked so well that no one questioned it until the 20th century.,(A) True (B) False,B,"Before World War II, people thought the seafloor was completely flat and featureless. There was no reason to think otherwise. "
ptolemys system to explain the motions of the planets,(A) Had the planets orbiting Earth (B) Had the planets orbiting Earth but also traveling in a small circle (C) Had the planets orbiting the Sun (D) Had the planets orbiting the Sun also with a retrograde motion,B,"The Astronomy of the ancient Greeks was linked to mathematics, and Greek astronomers sought to create geomet- rical models that could imitate the appearance of celestial motions. This tradition originated around the 6th century BCE, with the followers of the mathematician Pythagoras (~580 - 500 BCE). Pythagoras believed that everything was related to mathematics and that through mathematics everything could be predicted and measured in rhythmic patterns or cycles. He placed astronomy as one of the four mathematical arts, the others being arithmetic, geometry and music. While best known for the Pythagorean Theorem, Pythagoras did have some input into astronomy. By the time of Pythagoras, the five planets visible to the naked eye - Mercury, Venus, Mars, Jupiter and Saturn - had long been identified. The names of these planets were initially derived from Greek mythology before being given the equivalent Roman mythological names, which are the ones we still use today. The word planet is a Greek term meaning wanderer, as these bodies move across the sky at different speeds from the stars, which appear fixed in the same positions relative to each other. For part of the year Venus appears in the eastern sky as an early morning object before disappearing and reappearing a few weeks later in the evening western sky. Early Greek astronomers thought this was two different bodies and assigned the names Phosphorus and Hesperus to the morning and evening apparitions respectively. Pythagoras is given credit for being the first to realize that these two bodies were in fact the same planet, a notion he arrived at through observation and geometrical calculations. Pythagoras was also one of the first to think that the Earth was round, a theory that was finally proved around 330 BCE by Aristotle. (Although, as you are probably aware, many people in 1642 CE still believed the earth to be flat.) Aristotle (384 BCE - 322 BCE) demonstrates in his writings that he knew we see the moon by the light of the sun, how the phases of the moon occur, and understood how eclipses work. He also knew that the earth was a sphere. Philosophically, he argued that each part of the earth is trying to be pulled to the center of the earth, and so the earth would naturally take on a spherical shape. He then pointed out observations that support the idea of a spherical earth. First, the shadow of the earth on the moon during a lunar eclipse is always circular. The only shape that always casts a circular shadow is a sphere. Second, as one traveles more north or south, the positions of the stars in the sky change. There are constellations visible in the north that one cannot see in the south and vice versa. He related this to the curvature of the earth. Aristotle talked about the work of earlier Greeks, who had developed an earth centered model of the planets. In these models, the center of the earth is the center of all the other motions. While it is not sure if the earlier Greeks actually thought the planets moved in circles, it is clear that Aristotle did. Aristotle rejected a moving earth for two reasons. Most importantly he didnt understand inertia. To Aristotle, the natural state for an object was to be at rest. He believed that it takes a force in order for an object to move. Using Aristotles ideas, if the earth were moving through space, if you tripped, you would not be in contact with the earth, and so would get left behind in space. Since this obviously does not happen, the earth must not move. This misunderstanding of inertia confused scientists until the time of Galileo. A second, but not as important, reason Aristotle rejected a moving earth is that he recognized that if the earth moved and rotated around the sun, there would be an observable parallax of the stars. One cannot see stellar parallax with the naked-eye, so Aristotle concluded that the earth must be at rest. (The stars are so far away, that one needs a good telescope to measure stellar parallax, which was first measured in 1838.) Aristotle believed that the objects in the heavens are perfect and unchanging. Since he believed that the only eternal motion is circular with a constant speed, the motions of the planets must be circular. This came to be called The Principal of Uniform Circular Motion. Aristotle and his ideas became very important because they became incorporated into the Catholic Churchs theology in the twelfth century by Thomas Aquinas. In the early 16th century, the Church banned new interpretations of scripture and this included a ban on ideas of a moving earth. Claudius Ptolemy (90 - 168 CE) was a citizen of Egypt which was under Roman rule during Ptolemys lifetime. During his lifetime he was a mathematician, astronomer, and geographer. His theories dominated the worlds understanding of astronomy for over a thousand years. While it is known that many astronomers published works during this time, only Ptolemys work The Almagest survived. In it, he outlined his geometrical reasoning for a geocentric view of the Universe. As outlined in the Almagest, the Universe according to Ptolemy was based on five main points: 1) the celestial realm is spherical, 2) the celestial realm moves in a circle, 3) the earth is a sphere, 4) the celestial realm orbit is a circle centered on the earth, and 5) earth does not move. Ptolemy also identified eight circular orbits surrounding earth where the other planets existed. In order, they were the moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and the sphere of fixed stars. A serious problem with the earth-centered system was the fact that at certain times in their orbits, some of the planets appeared to move in the opposite direction of their normal movement. This reverse direction movement is referred to as retrograde motion. If the earth was to remain motionless at the center of the system, some very intricate designs were necessary to explain the movement of the retrograde planets. In the Ptolemaic system, each retrograde planet moved by two spheres. The Ptolemaic system had circles within circles that produced epicycles. In the sketch above on the left, the red ball moved clockwise in its little circle while the entire orbit also orbited clockwise around the big circle. This process produced a path like that shown in the sketch above on the right. As the red ball moved around its path, at some times it would be moving clockwise and then for a short period, it would move counterclockwise. This motion was able to explain the retrograde motion noted for some planets. "
keplers solar system model,(A) Has the sun in the center (B) Has the planets moving in elliptical orbits (C) Matches observations perfectly (D) All of the above,D,"Ptolemys geocentric model worked, but it was complicated and occasionally made errors in predicting the movement of planets. At the beginning of the 16th century A.D., Nicolaus Copernicus proposed that Earth and all the other planets orbit the Sun. With the Sun at the center, this model is called the heliocentric model, or ""sun-centered"" model. Although Copernicus model was simpler - it didnt need epicycles and deferents - it still did not perfectly describe the motion of the planets. Johannes Kepler solved the problem a short time later when he determined that the planets moved around the Sun in ellipses (ovals), not circles (Figure 1.2). Keplers model matched observations perfectly. The heliocentric model did not catch on right away. When Galileo Galilei first turned a telescope to the heavens in 1610, he made several striking discoveries. Galileo discovered that the planet Jupiter has moons orbiting around it. This provided the first evidence that objects could orbit something besides Earth. Galileo also discovered that Venus has phases like the Moon (Figure 1.3), which provides direct evidence that Venus orbits the Sun. Galileos discoveries caused many more people to accept the heliocentric model of the universe, although Galileo himself was found guilty of heresy. The shift from an Earth-centered view to a Sun-centered view of the universe is referred to as the Copernican Revolution. In their elliptical orbits, each planet is sometimes farther away from the Sun than at other times. This movement is called revolution. At the same time, Earth spins on its axis. Earths axis is an imaginary line passing through the Keplers model showed the planets moving around the Sun in ellipses. The phases of Venus. planets center that goes through both the North Pole and the South Pole. This spinning movement is called Earths rotation. "
"copernicus proposed that the planets orbit the sun, the heliocentric model.",(A) True (B) False,A,"Ptolemys geocentric model worked, but it was complicated and occasionally made errors in predicting the movement of planets. At the beginning of the 16th century A.D., Nicolaus Copernicus proposed that Earth and all the other planets orbit the Sun. With the Sun at the center, this model is called the heliocentric model, or ""sun-centered"" model. Although Copernicus model was simpler - it didnt need epicycles and deferents - it still did not perfectly describe the motion of the planets. Johannes Kepler solved the problem a short time later when he determined that the planets moved around the Sun in ellipses (ovals), not circles (Figure 1.2). Keplers model matched observations perfectly. The heliocentric model did not catch on right away. When Galileo Galilei first turned a telescope to the heavens in 1610, he made several striking discoveries. Galileo discovered that the planet Jupiter has moons orbiting around it. This provided the first evidence that objects could orbit something besides Earth. Galileo also discovered that Venus has phases like the Moon (Figure 1.3), which provides direct evidence that Venus orbits the Sun. Galileos discoveries caused many more people to accept the heliocentric model of the universe, although Galileo himself was found guilty of heresy. The shift from an Earth-centered view to a Sun-centered view of the universe is referred to as the Copernican Revolution. In their elliptical orbits, each planet is sometimes farther away from the Sun than at other times. This movement is called revolution. At the same time, Earth spins on its axis. Earths axis is an imaginary line passing through the Keplers model showed the planets moving around the Sun in ellipses. The phases of Venus. planets center that goes through both the North Pole and the South Pole. This spinning movement is called Earths rotation. "
"through the first-ever telescope, galileo discovered",(A) The elliptical orbits of the planets (B) Mercury has phases like the Moon (C) Jupiter is orbited by moons (D) All of these,C,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
which one of these is not a description of texture?,(A) Size (B) Shape (C) Arrangement of mineral grains (D) Color,D,"Luster describes the reflection of light off a minerals surface. Mineralogists have special terms to describe luster. One simple way to classify luster is based on whether the mineral is metallic or non-metallic. Minerals that are opaque and shiny, such as pyrite, have a metallic luster. Minerals such as quartz have a non-metallic luster. Different types of non-metallic luster are described in Table 1.1. Luster Adamantine Earthy Pearly Resinous Silky Vitreous Appearance Sparkly Dull, clay-like Pearl-like Like resins, such as tree sap Soft-looking with long fibers Glassy The streak of hematite across an unglazed porcelain plate is red-brown. "
"a rock made of grains that are so tiny they cannot be seen without a microscope is a rock, but it is not made of minerals.",(A) True (B) False,B,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
how does diorite differ from andesite?,(A) Different minerals are present (B) Very different colors (C) Crystal size (D) Composition of magma they cooled from,C,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
not all rocks contain grains that fit the definition of a mineral.,(A) True (B) False,A,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
two different rock types must always different in their,(A) Composition (B) Texture (C) Both composition and texture (D) Composition and texture (E) or composition or texture,A,Different factors play into the composition of a magma and the rock it produces. 
rocks are identified primarily by,(A) Their minerals and texture (B) The size and shape of their minerals (C) Their color (D) The arrangement of their mineral grains,A,1. Distinctive rock formations may be recognizable across large regions (Figure 1.1). 
"_______________________ is a naturally formed, non-living earth material.",(A) Rock (B) Coal (C) Fossil (D) Concrete,A,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
which one of these rocks does not contain minerals?,(A) Diorite (B) Granite (C) Coal (D) Pegmatite,C,"A rock is a naturally formed, non-living Earth material. Rocks are made of collections of mineral grains that are held together in a firm, solid mass (Figure 1.1). How is a rock different from a mineral? Rocks are made of minerals. The mineral grains in a rock may be so tiny that you can only see them with a microscope, or they may be as big as your fingernail or even your finger (Figure Rocks are identified primarily by the minerals they contain and by their texture. Each type of rock has a distinctive set of minerals. A rock may be made of grains of all one mineral type, such as quartzite. Much more commonly, rocks are made of a mixture of different minerals. Texture is a description of the size, shape, and arrangement of mineral grains. Are the two samples in Figure 1.3 the same rock type? Do they have the same minerals? The same texture? The different colors and textures seen in this rock are caused by the presence of different minerals. A pegmatite from South Dakota with crystals of lepidolite, tourmaline, and quartz (1 cm scale on the upper left). Sample 2 Crystals are tiny or microscopic Magma erupted and cooled quickly Andesite As seen in Table 1.1, these two rocks have the same chemical composition and contain mostly the same minerals, but they do not have the same texture. Sample 1 has visible mineral grains, but Sample 2 has very tiny or invisible grains. The two different textures indicate different histories. Sample 1 is a diorite, a rock that cooled slowly from magma (molten rock) underground. Sample 2 is an andesite, a rock that cooled rapidly from a very similar magma that erupted onto Earths surface. A few rocks are not made of minerals because the material they are made of does not fit the definition of a mineral. Coal, for example, is made of organic material, which is not a mineral. Can you think of other rocks that are not made of minerals? Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
diorite is a rock cooled from,(A) Lava (B) Magma (C) Metamorphic rocks (D) The core,B,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
the difference between diorite and andesite is,(A) Andesite cooled from erupted magma and diorite cooled from magma underground (B) Both rocks cooled from erupted magma (C) Both rocks cooled from magma underground (D) Andesite cooled from magma underground and diorite cooled from erupted magma,A,"Igneous rocks are grouped by the size of their crystals and the minerals they contain. The minerals in igneous rocks are grouped into families. Some contain mostly lighter colored minerals, some have a combination of light and dark minerals, and some have mostly darker minerals. The combination of minerals is determined by the composition of the magma. Magmas that produce lighter colored minerals are higher in silica. These create rocks such as granite and rhyolite. Darker colored minerals are found in rocks such as gabbro and basalt. There are actually more than 700 different types of igneous rocks. Diorite is extremely hard and is commonly used for art. It was used extensively by ancient civilizations for vases and other decorative art work (Figure 4.11). "
all rocks and rock types are part of the rock cycle.,(A) True (B) False,A,"The rock cycle, illustrated in Figure 1.1, depicts how the three major rock types - igneous, sedimentary, and meta- morphic - convert from one to another. Arrows connecting the rock types represent the processes that accomplish these changes. Rocks change as a result of natural processes that are taking place all the time. Most changes happen very slowly. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Even at the surface, we may not notice the changes. The rock cycle has no beginning or end. "
"rocks are classified into four major groups, reflecting how they formed: intrusive, extrusive, metamorphic and sedimentary.",(A) True (B) False,B,"Geologists group rocks based on how they were formed. The three main kinds of rocks are: 1. Igneous rocks form when magma cools below Earths surface or lava cools at the surface (Figure 4.3). 2. Sedimentary rocks form when sediments are compacted and cemented together (Figure 4.4). These sediments may be gravel, sand, silt or clay. Sedimentary rocks often have pieces of other rocks in them. Some sedimentary rocks form the solid minerals left behind after a liquid evaporates. 3. Metamorphic rocks form when an existing rock is changed by heat or pressure. The minerals in the rock change but do not melt (Figure 4.5). The rock experiences these changes within the Earth. Rocks can be changed from one type to another, and the rock cycle describes how this happens. "
what determines the type of igneous rock that forms from magma?,(A) The heat and pressure the magma is exposed to (B) Whether the magma enters water before it cools (C) Magma composition and cooling rate (D) The amount of compaction and cementation that affect the rock,C,The rate at which magma cools determines whether an igneous rock is intrusive or extrusive. The cooling rate is reflected in the rocks texture. 
which of the following characteristics of a rock is affected by the cooling rate of magma?,(A) The rock’s color (B) The rock’s texture (C) The rock’s hardness (D) The rock’s chemical composition,B,The rate at which magma cools determines whether an igneous rock is intrusive or extrusive. The cooling rate is reflected in the rocks texture. 
which of the following is a process of the rock cycle?,(A) Weathering (B) Crystallization (C) Metamorphosis (D) All of these,D,"Several processes can turn one type of rock into another type of rock. The key processes of the rock cycle are crystallization, erosion and sedimentation, and metamorphism. "
a rock is heated so much that it melts. what type of rock will it become?,(A) Igneous (B) Metamorphic (C) Sedimentary (D) Fossil,A,"You are on vacation at the beach. You take your flip-flops off so you can go swimming. The sand is so hot it hurts your feet. You have to run to the water. Now imagine if it were hot enough for the sand to melt. Some places inside Earth are so hot that rock melts. Melted rock inside the Earth is called magma. Magma can be hotter than 1,000C. When magma erupts onto Earths surface, it is known as lava, as Figure 3.17 shows. Minerals form when magma and lava cool. "
"in crystallization, slower cooling forms smaller crystals.",(A) True (B) False,B,"Magma cools either underground or on the surface and hardens into an igneous rock. As the magma cools, different crystals form at different temperatures, undergoing crystallization. For example, the mineral olivine crystallizes out of magma at much higher temperatures than quartz. The rate of cooling determines how much time the crystals will have to form. Slow cooling produces larger crystals. "
"_________________ happens when solid material separates out of a liquid, usually when the liquid evaporates.",(A) Weathering (B) Erosion (C) Sedimentation (D) Precipitation,D,A liquid can also change to a gas without boiling. This process is called evaporation. It occurs when particles at the exposed surface of a liquid absorb just enough energy to pull away from the liquid and escape into the air. This happens faster at warmer temperatures. Look at the puddle in Figure 4.21. It formed in a pothole during a rain shower. The puddle will eventually evaporate. It will evaporate faster if the sun comes out and heats the water than if the sky remains cloudy. 
"a rock transforms from one type to another by the processes of the rock cycle, but once it is transformed it is out of the rock cycle.",(A) True (B) False,B,"The rock cycle, illustrated in Figure 1.1, depicts how the three major rock types - igneous, sedimentary, and meta- morphic - convert from one to another. Arrows connecting the rock types represent the processes that accomplish these changes. Rocks change as a result of natural processes that are taking place all the time. Most changes happen very slowly. Rocks deep within the Earth are right now becoming other types of rocks. Rocks at the surface are lying in place before they are next exposed to a process that will change them. Even at the surface, we may not notice the changes. The rock cycle has no beginning or end. "
"this french scientist used a pendulum, which help to confirm earths movement",(A) Einstein (B) Newton (C) Foucault (D) Galileo,C,"In 1851, a French scientist named Lon Foucault took an iron sphere and hung it from a wire. He pulled the sphere to one side and then released it, as a pendulum. Although a pendulum set in motion should not change its motion, Foucault observed that his pendulum did seem to change direction relative to the circle below. Foucault concluded that Earth was moving underneath the pendulum. People at that time already knew that Earth rotated on its axis, but Foucaults experiment was nice confirmation. "
an imaginary line that runs through the center of the earth from the north to the south pole.,(A) Geographic Pole (B) Magnetic Pole (C) Axis (D) Equator,C,"Lines of latitude circle around Earth. The equator is a line of latitude right in the middle of the planet. The equator is an equal distance from both the North and South Pole. If you know your latitude, you know how far you are north or south of the equator. "
the earth rotates on its axis every,(A) 60 minutes (B) 24 hours (C) 365 days (D) 60 seconds,B,"Imagine a line passing through the center of Earth that goes through both the North Pole and the South Pole. This imaginary line is called an axis. Earth spins around its axis, just as a top spins around its spindle. This spinning movement is called Earths rotation. An observer in space will see that Earth requires 23 hours, 59 minutes, and 4 seconds to make one complete rotation on its axis. But because Earth moves around the Sun at the same time that it is rotating, the planet must turn just a little bit more to reach the same place relative to the Sun. Hence the length of a day on Earth is actually 24 hours. At the Equator, the Earth rotates at a speed of about 1,700 km per hour, but at the poles the movement speed is nearly nothing. "
the sun appears to move across the sky from west to east each day.,(A) True (B) False,B,"Earth rotates once on its axis about every 24 hours. To an observer looking down at the North Pole, the rotation appears counterclockwise. From nearly all points on Earth, the Sun appears to move across the sky from east to west each day. Of course, the Sun is not moving from east to west at all; Earth is rotating. The Moon and stars also seem to rise in the east and set in the west. Earths rotation means that there is a cycle of daylight and darkness approximately every 24 hours, the length of a day. Different places experience sunset and sunrise at different times and the amount of daylight and darkness also differs by location. Shadows are areas where an object obstructs a light source so that darkness takes on the form of the object. On Earth, a shadow can be cast by the Sun, Moon, or (rarely) Mercury or Venus. Click image to the left or use the URL below. URL: "
"a molecule at the equator rotates extremely fast, but a molecule at the south pole barely moves at all.",(A) True (B) False,A,"Earth is hottest at the equator and gets cooler toward the poles. The differences in heating create huge convection currents in the troposphere. At the equator, for example, warm air rises up to the tropopause. It cant rise any higher, so it flows north or south. By the time the moving air reaches 30 N or S latitude, it has cooled. The cool air sinks to the surface. Then it flows over the surface back to the equator. Other global winds occur in much the same way. There are three enormous convection cells north of the equator and three south of the equator. "
these things differ by location:,(A) Sunrise and sunset (B) The length of day and night (C) The amount of daylight and darkness (D) All of these,D,1. Distinctive rock formations may be recognizable across large regions (Figure 1.1). 
a pendulum in paris confirmed the existence of,(A) Earth’s rotation (B) Earth’s magnetic field (C) The geocentric model (D) The Equator,A,"In 1851, a French scientist named Lon Foucault took an iron sphere and hung it from a wire. He pulled the sphere to one side and then released it, as a pendulum. Although a pendulum set in motion should not change its motion, Foucault observed that his pendulum did seem to change direction relative to the circle below. Foucault concluded that Earth was moving underneath the pendulum. People at that time already knew that Earth rotated on its axis, but Foucaults experiment was nice confirmation. "
the earth rotational speed is about,(A) 700 km per hour (B) 1 (C) 000 km per hour (D) c 1 (E) 700 km per hour (F) d 2 (G) 000 km per hour,A,"Imagine a line passing through the center of Earth that goes through both the North Pole and the South Pole. This imaginary line is called an axis. Earth spins around its axis, just as a top spins around its spindle. This spinning movement is called Earths rotation. An observer in space will see that Earth requires 23 hours, 59 minutes, and 4 seconds to make one complete rotation on its axis. But because Earth moves around the Sun at the same time that it is rotating, the planet must turn just a little bit more to reach the same place relative to the Sun. Hence the length of a day on Earth is actually 24 hours. At the Equator, the Earth rotates at a speed of about 1,700 km per hour, but at the poles the movement speed is nearly nothing. "
shadows can be cast by,(A) Any strong light source (B) Only the Sun (C) Only the Sun and Moon (D) Only Mercury and Venus,A,"Many other objects appear to produce their own light, but they actually just reflect light from another source. Being lit by another source is called illumination. The moon in the Figure 1.4 is glowing so brightly that you can see shadows under the trees. It appears to glow from its own light, but its really just illuminated by light from the sun. Everything you can see that doesnt produce its own light is illuminated by light from some other source. "
the direction that the stars appear to move across the sky is due to earths rotation.,(A) True (B) False,A,"Earth rotates once on its axis about every 24 hours. To an observer looking down at the North Pole, the rotation appears counterclockwise. From nearly all points on Earth, the Sun appears to move across the sky from east to west each day. Of course, the Sun is not moving from east to west at all; Earth is rotating. The Moon and stars also seem to rise in the east and set in the west. Earths rotation means that there is a cycle of daylight and darkness approximately every 24 hours, the length of a day. Different places experience sunset and sunrise at different times and the amount of daylight and darkness also differs by location. Shadows are areas where an object obstructs a light source so that darkness takes on the form of the object. On Earth, a shadow can be cast by the Sun, Moon, or (rarely) Mercury or Venus. Click image to the left or use the URL below. URL: "
this sacred river india is sacred has affects 400 million people that depend on it.,(A) The Zambezi (B) The Ganges (C) The Yarra (D) The Volga,B,"Many people in the world have no choice but to drink from the same polluted river where sewage is dumped. One- fifth of all people in the world, more than 1.1 billion people, do not have access to safe water for drinking, personal cleanliness, and domestic use. Unsafe drinking water carries many pathogens, or disease-causing biological agents such as infectious bacteria and parasites. Toxic chemicals and radiological hazards in water can also cause diseases. "
"________________ of all people in the world have access to safe water for drinking, personal cleanliness, and domestic use.",(A) One-half (B) One-third (C) One-fourth (D) One-fifth,D,"Many people in the world have no choice but to drink from the same polluted river where sewage is dumped. One- fifth of all people in the world, more than 1.1 billion people, do not have access to safe water for drinking, personal cleanliness, and domestic use. Unsafe drinking water carries many pathogens, or disease-causing biological agents such as infectious bacteria and parasites. Toxic chemicals and radiological hazards in water can also cause diseases. "
pathogens are _________________.,(A) Infectious living things (B) Toxic chemicals (C) Radioactive materials (D) All of the above,A,"You have ten times as many bacterial cells as human cells in your body. Luckily for you, most of these bacteria are harmless. However, some of them can cause disease. Any organism that causes disease is called a pathogen. Diseases caused by bacterial pathogens include food poisoning, strep throat, and Lyme disease. Bacteria that cause disease may spread directly from person to person. For example, they may spread when people shake hands with, or sneeze on, other people. Bacteria may also spread through food, water, or objects that have become contaminated with them. Some bacteria are spread by vectors. A vector is an organism that spreads bacteria or other pathogens. Most vectors are animals, commonly insects. For example, deer ticks like the one in Figure 8.13 spread Lyme disease. Ticks carry Lyme disease bacteria from deer to people when they bite them. "
toxic bacteria can quickly become dangerous because ____________.,(A) Their population increases exponentially (B) They are tiny (C) They stay in one place and infect everyone nearby (D) All of these,A,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
in many nations diseases carried in drinking water are the leading cause of death for children under the age of five.,(A) True (B) False,A,"Waterborne disease caused by unsafe drinking water is the leading cause of death for children under the age of five in many nations and a cause of death and illness for many adults. About 88% of all diseases are caused by drinking unsafe water (Figure 1.1). Throughout the world, more than 14,000 people die every day from waterborne diseases, such as cholera, and many of the worlds hospital beds are occupied by patients suffering from a waterborne disease. Guinea worm is a serious problem in parts of Africa that is being eradicated. Learn what is being done to decrease the number of people suffering from this parasite at the video below. Click image to the left or use the URL below. URL: "
more than ___________ people die every day from waterborne disease.,(A) 10 (B) 000 (C) b 11 (D) 000 (E) c 12 (F) 000 (G) d 14 (H) 000,D,"Waterborne disease caused by unsafe drinking water is the leading cause of death for children under the age of five in many nations and a cause of death and illness for many adults. About 88% of all diseases are caused by drinking unsafe water (Figure 1.1). Throughout the world, more than 14,000 people die every day from waterborne diseases, such as cholera, and many of the worlds hospital beds are occupied by patients suffering from a waterborne disease. Guinea worm is a serious problem in parts of Africa that is being eradicated. Learn what is being done to decrease the number of people suffering from this parasite at the video below. Click image to the left or use the URL below. URL: "
which of these is an example of a waterborne disease?,(A) Small pox (B) The flu (C) Cholera (D) The cold,C,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
dracunculiasis spreads when people drink adult guinea worms.,(A) True (B) False,B,"Waterborne disease caused by unsafe drinking water is the leading cause of death for children under the age of five in many nations and a cause of death and illness for many adults. About 88% of all diseases are caused by drinking unsafe water (Figure 1.1). Throughout the world, more than 14,000 people die every day from waterborne diseases, such as cholera, and many of the worlds hospital beds are occupied by patients suffering from a waterborne disease. Guinea worm is a serious problem in parts of Africa that is being eradicated. Learn what is being done to decrease the number of people suffering from this parasite at the video below. Click image to the left or use the URL below. URL: "
"the solution to stopping the spread of waterborne diseases is always large, expensive public work projects.",(A) True (B) False,B,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
people in developed nations dont think much about waterborne diseases because our water is treated and is almost always safe to drink.,(A) True (B) False,A,The water that comes out of our faucets is safe because it has gone through a series of treatment and purification processes to remove contaminants. Those of us who are fortunate enough to always be able to get clean water from a tap in our home may have trouble imagining life in a country that cannot afford the technology to treat and purify water. 
this is propelled into space by particles flying out one end at high speed.,(A) Plane (B) Rocket (C) Satellite (D) Helicopter,B,"A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. "
which of newtons laws of motion explains rocket propulsion?,(A) First (B) Second (C) Third (D) Fourth,C,"Rockets were used for centuries before anyone could explain how they worked. The theory came about in 1687. Isaac Newton (16431727) described three basic laws of motion, now referred to as Newtons Laws of Motion: 1. An object in motion will remain in motion unless acted upon by a force. 2. Force equals mass multiplied by acceleration. 3. To every action, there is an equal and opposite reaction. Which of these three best explains how a rocket works? Newtons third law of motion. When a rockets propulsion pushes in one direction, the rocket moves in the opposite direction, as seen in the Figure 23.12. For a long time, many people believed that a rocket wouldnt work in space. There would be nothing for the rocket to push against. But they do work! Fuel is ignited in a chamber. The gases in the chamber explode. The explosion creates pressure that forces the gases out of one side of the rocket. The rocket moves in the opposite direction, as shown in Figure 23.13. The force pushing the rocket is called thrust. "
any object that orbits a larger object is a(n),(A) Earth (B) Moon (C) Satellite (D) Plane,C,One of the first uses of rockets in space was to launch satellites. A satellite is an object that orbits a larger object. An orbit is a circular or elliptical path around an object. Natural objects in orbit are called natural satellites. The Moon is a natural satellite. Human-made objects in orbit are called artificial satellites. There are more and more artificial satellites orbiting Earth all the time. They all get into space using some sort of rocket. 
imaging satellites,(A) Take photos of Earth for scientific or military purposes (B) Are used only to study Earth (C) Transmit images to satellite dishes for television sets (D) None of these,A,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
gps uses this type of satellite.,(A) Communications satellite (B) Imaging Satellite (C) Navigational Satellite (D) The International Space Station,C,"In order to locate your position on a map, you must know your latitude and your longitude. But you need several instruments to measure latitude and longitude. What if you could do the same thing with only one instrument? Satellites can also help you locate your position on the Earths surface. By 1993, the United States military had launched 24 satellites to help soldiers locate their positions on battlefields. This system of satellites was called the Global Positioning System (GPS). Later, the United States government allowed the public to use this system. Heres how it works. You must have a GPS receiver to use the system (Figure 2.38). You can buy many types of these in stores. The "
"the largest artificial satellite, which is designed for human habitation is",(A) Human-Occupied Satellite (B) Imaging Satellite (C) Navigational Satellite (D) The International Space Station,D,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
satellites used for televisions and phones are,(A) Carry a lot of cargo (B) Take people to a space station (C) Be used many times (D) All of these,D,"The first artificial satellite was launched just over 50 years ago. Thousands are now in orbit around Earth. Satellites have orbited other objects in the solar system. These include the Moon, the Sun, Venus, Mars, Jupiter, and Saturn. Satellites have many different purposes. Imaging satellites take pictures Earths surface. These images are used for military or scientific purposes. Astronomers use imaging satellites to study and make maps of the Moon and other planets. Communications satellites, such as the one in Figure 23.18, are now extremely common. These satellites receive and send signals for telephone, television, or other types of communications. Navigational satellites are used for navigation systems, such as the Global Positioning System (GPS). The largest artificial satellite is the International Space Station. The ISS is designed for humans to live in space while conducting scientific research. "
"for every action there is an equal and opposite reaction, also known as thrust.",(A) True (B) False,A,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
the main purpose of the international space station is,(A) Peace negotiations between Europe (B) the United States and Russia (C) b Scientific research (D) c Breaking the record for days in space by a human (E) d Breaking the record for days in space by a number of humans,B,"Humans have a presence in space at the International Space Station (ISS) (pictured in Figure 1.3). Modern space stations are constructed piece by piece to create a modular system. The primary purpose of the ISS is scientific research, especially in medicine, biology, and physics. "
saturn is,(A) The only planet with rings that we can see from Earth (B) The densest planet (C) The most massive planet (D) All of these,A,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
"if you could find a bathtub big enough, you could put enough water to float saturn in it.",(A) True (B) False,A,"Saturn, shown in Figure 1.1, is famous for its beautiful rings. Although all the gas giants have rings, only Saturns can be easily seen from Earth. In Roman mythology, Saturn was the father of Jupiter. Saturns mass is about 95 times the mass of Earth, and its volume is 755 times Earths volume, making it the second largest planet in the solar system. Saturn is also the least dense planet in the solar system. It is less dense than water. What would happen if you had a large enough bathtub to put Saturn in? Saturn would float! Saturn orbits the Sun once about every 30 Earth years. Like Jupiter, Saturn is made mostly of hydrogen and helium gases in the outer layers and liquids at greater depths. The upper atmosphere has clouds in bands of different colors. These rotate rapidly around the planet, but there seems to be less turbulence and fewer storms on Saturn than on Jupiter. One interesting phenomenon that has been observed in the storms on Saturn is the presence of thunder and lightning (see video, below). The planet likely has a small rocky and metallic core. This image of Saturn and its rings is a composite of pictures taken by the Cassini orbiter in 2008 "
saturns rings are connected to the planet.,(A) True (B) False,B,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
what makes up saturns rings?,(A) Water (B) Ice (C) Dust and rocks (D) All of the above,D,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
enceladus could be home to life because it has,(A) Internal heat (B) Methane (C) Water ice (D) All of the above,A,"Most of Saturns moons are very small, and only seven are large enough for gravity to have made them spherical. Only Titan is larger than Earths Moon at about 1.5 times its size. Titan is even larger than the planet Mercury. Scientists are interested in Titan because its atmosphere is similar to what Earths was like before life developed. Nitrogen is dominant and methane is the second most abundant gas. Titan may have a layer of liquid water and ammonia under a layer of surface ice. Lakes of liquid methane (CH4 ) and ethane (C2 H6 ) are found on Titans surface. Although conditions are similar enough to those of early Earth for scientists to speculate that extremely A color-exaggerated mosaic of Saturn and its rings taken by Cassini as Saturn eclipses the Sun. A close-up of Saturns outer C ring show- ing areas with higher particle concentra- tion and gaps. This composite image compares Saturns largest moon, Titan (right) to Earth (left). Click image to the left or use the URL below. URL: "
saturns atmosphere,(A) Has a Great Red Spot like Jupiter (B) Has clouds in different colored bands (C) Has thunder and lightning (D) All of the above,C,"Saturn, shown in Figure 25.22, is famous for its beautiful rings. Saturn is the second largest planet in the solar system. Saturns mass is about 95 times Earths mass. The gas giant is 755 times Earths volume. Despite its large size, Saturn is the least dense planet in our solar system. Saturn is actually less dense than water. This means that if there were a bathtub big enough, Saturn would float! In Roman mythology, Saturn was the father of Jupiter. Saturn orbits the Sun once about every 30 Earth years. Saturns composition is similar to Jupiters. The planet is made mostly of hydrogen and helium. These elements are gases in the outer layers and liquids in the deeper layers. Saturn may also have a small solid core. Saturns upper atmosphere has clouds in bands of different colors. These clouds rotate rapidly around the planet. But Saturn has fewer storms than Jupiter. Thunder and lightning have been seen in the storms on Saturn (Figure 25.23). "
saturns rings,(A) Were first seen by Galileo through his telescope (B) Appear tilted because Saturn is tilted (C) Have gaps due to the gravitational pull of Saturn or its moons (D) All of the above,D,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
saturns atmosphere is just as stormy s jupiters.,(A) True (B) False,B,"Saturn, shown in Figure 1.1, is famous for its beautiful rings. Although all the gas giants have rings, only Saturns can be easily seen from Earth. In Roman mythology, Saturn was the father of Jupiter. Saturns mass is about 95 times the mass of Earth, and its volume is 755 times Earths volume, making it the second largest planet in the solar system. Saturn is also the least dense planet in the solar system. It is less dense than water. What would happen if you had a large enough bathtub to put Saturn in? Saturn would float! Saturn orbits the Sun once about every 30 Earth years. Like Jupiter, Saturn is made mostly of hydrogen and helium gases in the outer layers and liquids at greater depths. The upper atmosphere has clouds in bands of different colors. These rotate rapidly around the planet, but there seems to be less turbulence and fewer storms on Saturn than on Jupiter. One interesting phenomenon that has been observed in the storms on Saturn is the presence of thunder and lightning (see video, below). The planet likely has a small rocky and metallic core. This image of Saturn and its rings is a composite of pictures taken by the Cassini orbiter in 2008 "
scientists are interested in titan because,(A) It is very likely to have microbial life (B) Its atmosphere is similar to Earth’s early atmosphere (C) It is the same size as Earth (D) All of these,B,"Most of Saturns moons are very small, and only seven are large enough for gravity to have made them spherical. Only Titan is larger than Earths Moon at about 1.5 times its size. Titan is even larger than the planet Mercury. Scientists are interested in Titan because its atmosphere is similar to what Earths was like before life developed. Nitrogen is dominant and methane is the second most abundant gas. Titan may have a layer of liquid water and ammonia under a layer of surface ice. Lakes of liquid methane (CH4 ) and ethane (C2 H6 ) are found on Titans surface. Although conditions are similar enough to those of early Earth for scientists to speculate that extremely A color-exaggerated mosaic of Saturn and its rings taken by Cassini as Saturn eclipses the Sun. A close-up of Saturns outer C ring show- ing areas with higher particle concentra- tion and gaps. This composite image compares Saturns largest moon, Titan (right) to Earth (left). Click image to the left or use the URL below. URL: "
scientists are certain that saturns rings formed when one if its moons broke apart.,(A) True (B) False,B,"In 1610, Galileo first observed Saturns rings with his telescope, but he thought they might be two large moons, one on either side of the planet. In 1659, the Dutch astronomer Christian Huygens realized that the features were rings (Figure 1.2). Saturns rings circle the planets equator and appear tilted because Saturn itself is tilted about 27 degrees. The rings do not touch the planet. The Voyager 1 and 2 spacecraft in 1980 and 1981 sent back detailed pictures of Saturn, its rings, and some of its moons. Saturns rings are made of particles of water and ice, with some dust and rocks (Figure 1.3). There are several gaps in the rings that scientists think have originated because the material was cleared out by the gravitational pull within the rings, or by the gravitational forces of Saturn and of moons outside the rings. The rings were likely formed by the breakup of one of Saturns moons or from material that never accreted into the planet when Saturn originally formed. "
which of these are types of scientific models?,(A) Conceptual (B) Mathematical (C) Physical (D) All of the above,D,"A model is a representation of an object, system, or process. For example, a road map is a representation of an actual system of roads on the ground. Models are very useful in science. They provide a way to investigate things that are too small, large, complex, or distant to investigate directly. To be useful, a model must closely represent the real thing in important ways, but it must be simpler and easier to understand than the real thing. Q: What might be examples of things that would be modeled in physical science because they are difficult to investigate directly? A: Examples include extremely small things such as atoms, very distant objects such as stars, and complex systems such as the electric grid that carries electricity throughout the country. Q: What are ways that these things might be modeled? A: Types of models include two-dimensional diagrams, three-dimensional structures, mathematical formulas, and computer simulations. Examples of simple two-dimensional models in physical science are described below. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
a globe is an example of a,(A) Mathematical model (B) Conceptual model (C) Physical model (D) None of the above,C,"Earth is a sphere and so is a globe. A globe is the best way to make a map of the whole Earth. Because both the planet and a globe have curved surfaces, the sizes and shapes of countries are not distorted. Distances are true to scale. (Figure 2.23). Globes usually have a geographic coordinate system and a scale. The shortest distance between two points on a globe is the length of the portion of a circle that connects them. Globes are difficult to make and carry around. They also cannot be enlarged to show the details of any particular area. Globes are best sitting on your desk for reference. Google Earth is a neat site to download to your computer. This is a link that you can follow to get there: http://w tilt your image and lots more. "
models,(A) Are useful tools (B) Are used to make predictions (C) Have limitations (D) All of the above,D,"Did you ever read a road map, sketch an object, or play with toy trucks or dolls? No doubt, the answer is yes. What do all these activities have in common? They all involve models. A model is a representation of an object, system, or process. For example, a road map is a representation of an actual system of roads on the ground. Models are very useful in science. They provide a way to investigate things that are too small, large, complex, or distant to investigate directly. Figure 2.10 shows an example of a model in chemistry. To be useful, a model must closely represent the real thing in important ways, but it must be simpler and easier to manipulate than the real thing. Do you think the model in Figure 2.10 meets these criteria? "
models can be used to make predictions.,(A) True (B) False,A,"How can scientists know if a model designed to predict the future is likely to be accurate, since it may not be possible to wait long enough to see if the prediction comes true? One way is to run the model using a time in the past as the starting point see if the model can accurately predict the present. A model that can successfully predict the present is more likely to be accurate when predicting the future. Many models are created on computers because only computers can handle and manipulate such enormous amounts of data. For example, climate models are very useful for trying to determine what types of changes we can expect as the composition of the atmosphere changes. A reasonably accurate climate model would be impossible on anything other than the most powerful computers. "
which of the models is likely to be most accurate?,(A) Mathematical model (B) Conceptual model (C) One that can predict the present (D) One that has the least detail,C,"How can scientists know if a model designed to predict the future is likely to be accurate, since it may not be possible to wait long enough to see if the prediction comes true? One way is to run the model using a time in the past as the starting point see if the model can accurately predict the present. A model that can successfully predict the present is more likely to be accurate when predicting the future. Many models are created on computers because only computers can handle and manipulate such enormous amounts of data. For example, climate models are very useful for trying to determine what types of changes we can expect as the composition of the atmosphere changes. A reasonably accurate climate model would be impossible on anything other than the most powerful computers. "
what are some limitations of models?,(A) Models only show a portion of a system (B) Are more complicated than the real object or system (C) Include too many variables that affect predictions (D) All of these,A,"Since models are simpler than real objects or systems, they have limitations. A model deals with only a portion of a system. It may not predict the behavior of the real system very accurately. But the more computing power that goes into the model and the care with which the scientists construct the model can increase the chances that a model will be accurate. "
a map of the entire world is an accurate physical model.,(A) True (B) False,B,"Earth is a sphere and so is a globe. A globe is the best way to make a map of the whole Earth. Because both the planet and a globe have curved surfaces, the sizes and shapes of countries are not distorted. Distances are true to scale. (Figure 2.23). Globes usually have a geographic coordinate system and a scale. The shortest distance between two points on a globe is the length of the portion of a circle that connects them. Globes are difficult to make and carry around. They also cannot be enlarged to show the details of any particular area. Globes are best sitting on your desk for reference. Google Earth is a neat site to download to your computer. This is a link that you can follow to get there: http://w tilt your image and lots more. "
computers that use mathematical models to predict the weather are always accurate.,(A) True (B) False,B,"The most accurate weather forecasts are made by advanced computers, with analysis and interpretation added by experienced meteorologists. These computers have up-to-date mathematical models that can use much more data and make many more calculations than would ever be possible by scientists working with just maps and calculators. Meteorologists can use these results to give much more accurate weather forecasts and climate predictions. In Numerical Weather Prediction (NWP), atmospheric data from many sources are plugged into supercomputers running complex mathematical models (Figure 1.1). The models then calculate what will happen over time at various altitudes for a grid of evenly spaced locations. The grid points are usually between 10 and 200 kilometers apart. Using the results calculated by the model, the program projects weather further into the future. It then uses these results to project the weather still further into the future, as far as the meteorologists want to go. Once a forecast is made, it is broadcast by satellites to more than 1,000 sites around the world. NWP produces the most accurate weather forecasts, but as anyone knows, even the best forecasts are not always right. Weather prediction is extremely valuable for reducing property damage and even fatalities. If the proposed track of a hurricane can be predicted, people can try to secure their property and then evacuate (Figure 1.2). A weather forecast using numerical weather prediction. "
the evidence that old seafloor is destroyed at deep-sea trenches includes,(A) Heat flow is high at the trenches (B) Magnetic stripes end at the trenches (C) The crust is very thin at the trenches (D) All of the above,B,"Scientists were surprised to find huge mountains and deep trenches when they mapped the seafloor. The mid-ocean ridges form majestic mountain ranges through the deep oceans (Figure 6.10). Deep sea trenches are found near chains of active volcanoes. These volcanoes can be at the edges of continents or in the oceans. Trenches are the deepest places on Earth. The deepest trench is the Mariana Trench in the southwestern Pacific Ocean. This trench plunges about 11 kilometers (35,840 feet) beneath sea level. The ocean floor does have lots of flat areas. These abyssal plains are like the scientists had predicted. "
why did harry hess call his paper describing plate tectonics an essay in geopoetry?,(A) Some of the data fit and some needed poetic license to make part of the story (B) The ideas presented were just a fantasy (C) The data all fit together so well (D) that it hardly seemed possible (E) d He wrote the paper in rhyme,C,"Harry Hess was a geology professor and a naval officer who commanded an attack transport ship during WWII. Like other ships, Hesss ship had echo sounders that mapped the seafloor. Hess discovered hundreds of flat-topped mountains in the Pacific that he gave the name guyot. He puzzled at what could have formed mountains that appeared to be eroded at the top but were more than a mile beneath the sea surface. Hess also noticed trenches that were as much as 7 miles deep. Meanwhile, other scientists like Bruce Heezen discovered the underwater mountain range they called the Great Global Rift. Although the rift was mostly in the deep sea, it occasionally came close to land. These scientists thought the rift was a set of breaks in Earths crust. The final piece that was needed was the work of Vine and Matthews, who had discovered the bands of alternating magnetic polarity in the seafloor symmetrically about the rift. "
flat-topped underwater mountains are called,(A) Guyots (B) Plateaus (C) Mid-ocean ridges (D) Mesas,A,"Harry Hess was a geology professor and a naval officer who commanded an attack transport ship during WWII. Like other ships, Hesss ship had echo sounders that mapped the seafloor. Hess discovered hundreds of flat-topped mountains in the Pacific that he gave the name guyot. He puzzled at what could have formed mountains that appeared to be eroded at the top but were more than a mile beneath the sea surface. Hess also noticed trenches that were as much as 7 miles deep. Meanwhile, other scientists like Bruce Heezen discovered the underwater mountain range they called the Great Global Rift. Although the rift was mostly in the deep sea, it occasionally came close to land. These scientists thought the rift was a set of breaks in Earths crust. The final piece that was needed was the work of Vine and Matthews, who had discovered the bands of alternating magnetic polarity in the seafloor symmetrically about the rift. "
the alternating stripes of normal and reverse magnetism in seafloor basalts on the sides of the mid-ocean ridges led to the idea of,(A) Magnetic Rifting (B) Continental Drift (C) Plate Drift (D) Seafloor spreading,D,"Scientists were also surprised to discover a pattern of stripes of normal and reversed polarity. These stripes surround the mid-ocean ridges. There is one long stripe with normal magnetism at the top of the ridge. Next to that stripe are two long stripes with reversed magnetism. One is on either side of the normal stripe. Next come two normal stripes and then two reversed stripes, and so on across the ocean floor. The magnetic stripes end abruptly at the edges of continents. Sometimes the stripes end at a deep sea trench (Figure 6.11). "
older crust is hot and more buoyant than younger crust.,(A) True (B) False,B,"Lighter materials accumulated at the surface of the mantle to become the earliest crust. The first crust was probably basaltic, like the oceanic crust is today. Intense heat from the early core drove rapid and vigorous mantle convection so that crust quickly recycled into the mantle. The recycling of basaltic crust was so effective that no remnants of it are found today. "
harry hess suggested that guyots were,(A) Eroded mountains that remained stationary as sea level rose (B) Eroded beaches that sank below sea level (C) Volcanoes that were exposed to erosion above sea level and then sunk (D) None of these,C,"Harry Hess was a geology professor and a naval officer who commanded an attack transport ship during WWII. Like other ships, Hesss ship had echo sounders that mapped the seafloor. Hess discovered hundreds of flat-topped mountains in the Pacific that he gave the name guyot. He puzzled at what could have formed mountains that appeared to be eroded at the top but were more than a mile beneath the sea surface. Hess also noticed trenches that were as much as 7 miles deep. Meanwhile, other scientists like Bruce Heezen discovered the underwater mountain range they called the Great Global Rift. Although the rift was mostly in the deep sea, it occasionally came close to land. These scientists thought the rift was a set of breaks in Earths crust. The final piece that was needed was the work of Vine and Matthews, who had discovered the bands of alternating magnetic polarity in the seafloor symmetrically about the rift. "
the mechanism for continental drift that wegener never knew about is,(A) Gases (B) Convection currents (C) Conveyor Belts (D) Gravity,B,"Wegener had many thoughts regarding what could be the driving force behind continental drift. Another of We- geners colleagues, Arthur Holmes, elaborated on Wegeners idea that there is thermal convection in the mantle. In a convection cell, material deep beneath the surface is heated so that its density is lowered and it rises. Near the surface it becomes cooler and denser, so it sinks. Holmes thought this could be like a conveyor belt. Where two adjacent convection cells rise to the surface, a continent could break apart with pieces moving in opposite directions. Although this sounds like a great idea, there was no real evidence for it, either. Alfred Wegener died in 1930 on an expedition on the Greenland icecap. For the most part the continental drift idea was put to rest for a few decades, until technological advances presented even more evidence that the continents moved and gave scientists the tools to develop a mechanism for Wegeners drifting continents. Since youre on a virtual field trip, you get to go along with them as well. Click image to the left or use the URL below. URL: "
harry hess suggested that old oceanic crust was,(A) Recycled back into the mantle (B) Adhered onto the continents (C) Created at mid-ocean ridges (D) The source of the flat-topped guyots,A,"The features of the seafloor and the patterns of magnetic polarity symmetrically about the mid-ocean ridges were the pieces that Hess needed. He resurrected Wegeners continental drift hypothesis and also the mantle convection idea of Holmes. Hess wrote that hot magma rose up into the rift valley at the mid-ocean ridges. The lava oozed up and forced the existing seafloor away from the rift in opposite directions. Since magnetite crystals point in the direction of the magnetic north pole as the lava cools, the different stripes of magnetic polarity revealed the different ages of the seafloor. The seafloor at the ridge is from the Brunhes normal; beyond that is basalt from the Matuyama reverse; and beyond that from the Gauss normal. Hess called this idea seafloor spreading. As oceanic crust forms and spreads, moving away from the ridge crest, it pushes the continent away from the ridge axis. If the oceanic crust reaches a deep sea trench, it sinks into the trench and is lost into the mantle. The oldest crust is coldest and lies deepest in the ocean because it is less buoyant than the hot new crust. Hess could also use seafloor spreading to explain the flat topped guyots. He suggested that they were once active volcanoes that were exposed to erosion above sea level. As the seafloor they sat on moved away from the ridge, the crust on which they sat become less buoyant and the guyots moved deeper beneath sea level. "
the rock made underwater from cooled lava is basalt.,(A) True (B) False,A,"Oceanic crust is composed of mafic magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro (Figure 1.1). Gabbro from ocean crust. The gabbro is deformed because of intense faulting at the eruption site. Sediments, primarily mud and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore, where it comes off the continents in rivers and on wind currents. The oceanic crust is relatively thin and lies above the mantle. The cross section of oceanic crust in the Figure 1.2 shows the layers that grade from sediments at the top to extrusive basalt lava, to the sheeted dikes that feed lava to the surface, to deeper intrusive gabbro, and finally to the mantle. "
how do continents move?,(A) Seafloor spreading creates new seafloor (B) which grows up to be new continents that move away from the ridge (C) b Convection currents create seafloor spreading (D) which pushes the lithospheric plate and (E) c Eruptions of lava at deep-sea trenches create continents (F) which move across the seafloor (G) d None of these,B,"Scientists think that Pangaea was not the first supercontinent. There were others before it. The continents are now moving together. This is because of subduction around the Pacific Ocean. Eventually, the Pacific will disappear and a new supercontinent will form. This wont be for hundreds of millions of years. The creation and breakup of a supercontinent takes place about every 500 million years. "
the reasons for the seasons is,(A) Earth’s elliptical orbit (B) Different output of solar radiation (C) Gravitational pull of the moon (D) The tilt of Earth’s axis,D,"Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. Different areas also receive different amounts of sunlight in different seasons. What causes the seasons? The seasons are caused by the direction Earths axis is pointing relative to the Sun. The Earth revolves around the Sun once each year and spins on its axis of rotation once each day. This axis of rotation is tilted 23.5o relative to its plane of orbit around the Sun. The axis of rotation is pointed toward Polaris, the North Star. As the Earth orbits the Sun, the tilt of Earths axis stays lined up with the North Star. "
this refers to when the position of the sun is closest to one of the poles.,(A) Equinox (B) Solstice (C) Summer (D) Winter,B,"The North Pole is tilted towards the Sun and the Suns rays strike the Northern Hemisphere more directly in summer (Figure 1.2). At the summer solstice, June 21 or 22, the Suns rays hit the Earth most directly along the Tropic of Cancer (23.5o N); that is, the angle of incidence of the Suns rays there is zero (the angle of incidence is the deviation in the angle of an incoming ray from straight on). When it is summer solstice in the Northern Hemisphere, it is winter solstice in the Southern Hemisphere. "
"during the summer, we experience shorter days and longer nights.",(A) True (B) False,B,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
this area has relatively the same amount of sunlight through the year.,(A) North Pole (B) South Pole (C) Equator (D) Axis,C,"Many factors influence the climate of a region. The most important factor is latitude because different latitudes receive different amounts of solar radiation. The Equator receives the most solar radiation. Days are equally long year-round and the Sun is just about directly overhead at midday. The polar regions receive the least solar radiation. The night lasts six months during the winter. Even in summer, the Sun never rises very high in the sky. Sunlight filters through a thick wedge of atmosphere, making the sunlight much less intense. The high albedo, because of ice and snow, reflects a good portion of the Suns light. "
the part of earth that receives the most solar radiation over a year is,(A) The Tropic of Cancer (B) The Equator (C) The North Pole (D) Every place receives the same amount,B,Different parts of the Earth receive different amounts of solar radiation. Which part of the planet receives the most solar radiation? The Suns rays strike the surface most directly at the Equator. The difference in solar energy received at different latitudes drives atmospheric circulation. 
during the winter solstice,(A) Earth’s axis in the Northern Hemisphere tilts away from the sun (B) The days and nights are the same length (C) The sun is directly above the equator (D) All of the above,A,"Winter solstice for the Northern Hemisphere happens on December 21 or 22. The tilt of Earths axis points away from the Sun (Figure 1.3). Light from the Sun is spread out over a larger area, so that area isnt heated as much. With fewer daylight hours in winter, there is also less time for the Sun to warm the area. When it is winter in the Northern Hemisphere, it is summer in the Southern Hemisphere. "
which is true about the equinox?,(A) It is halfway between the two solstices (B) The daylight and the nighttime hours are exactly equal (C) There is a vernal and an autumnal one (D) All of the above,C,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
the time when daylight and nighttime hours are exactly equal.,(A) Solstice (B) Equality (C) Hemisphere (D) Equinox,D,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
"earths axis of rotation is pointed toward polaris, the north star, in the summer, but away from polar in the winter.",(A) True (B) False,B,"The Earth is tilted 23 1/2 on its axis (Figure 24.10). This means that as the Earth rotates, one hemisphere has longer days with shorter nights. At the same time the other hemisphere has shorter days and longer nights. For example, in the Northern hemisphere summer begins on June 21. On this date, the North Pole is pointed directly toward the Sun. This is the longest day and shortest night of the year in the Northern Hemisphere. The South Pole is pointed away from the Sun. This means that the Southern Hemisphere experiences its longest night and shortest day (Figure 24.11). The hemisphere that is tilted away from the Sun is cooler because it receives less direct rays. As Earth orbits the Sun, the Northern Hemisphere goes from winter to spring, then summer and fall. The Southern Hemisphere does the opposite from summer to fall to winter to spring. When it is winter in the Northern hemisphere, it is summer in the Southern hemisphere, and vice versa. "
the vernal equinox happens around september 22 or 23.,(A) True (B) False,A,"Halfway between the two solstices, the Suns rays shine most directly at the Equator, called an equinox (Figure 1.4). The daylight and nighttime hours are exactly equal on an equinox. The autumnal equinox happens on September 22 or 23 and the vernal, or spring, equinox happens March 21 or 22 in the Northern Hemisphere. Summer solstice in the Northern Hemisphere. Click image to the left or use the URL below. URL: "
water is good at dissolving salts and other substances because,(A) It is a polar molecule (B) It has more ionic charge than other substances (C) It is present on Earth as a gas (D) liquid and solid (E) d It is wet,A,"Remember that H2 O is a polar molecule, so it can dissolve many substances (Figure 1.1). Salts, sugars, acids, bases, and organic molecules can all dissolve in water. "
"in an estuary,",(A) There is a lot of evaporation so the water is very saline (B) Calcium chloride is more abundant than sodium chloride due to river runoff (C) Seawater mixes with freshwater so the water has intermediate salinity (D) The salinity is constant,C,"Marshes are shallow wetlands around lakes, streams, or the ocean where grasses and reeds are common, but trees are not (Figure 1.2). Frogs, turtles, muskrats, and many varieties of birds are at home in marshes. A salt marsh on Cape Cod in Mas- sachusetts. "
salts in seawater are made with,(A) Chlorine as the anion (B) Sodium as the most abundant cation (C) Magnesium or calcium as cations (D) All of the above,D,"Have you ever gone swimming in the ocean? If you have, then you probably tasted the salts in the water. By mass, salts make up about 3.5 percent of ocean water. Figure 14.5 shows the most common minerals in ocean water. The main components are sodium and chloride. Together they form the salt known as sodium chloride. You may know the compound as table salt or the mineral halite. The amount of salts in ocean water varies from place to place. For example, near the mouth of a river, ocean water may be less salty. Thats because river water contains less salt than ocean water. Where the ocean is warm, the water may be more salty. Can you explain why? (Hint: More water evaporates when the water is warm.) "
all salt is dangerous for humans and we should eat only a tiny amount each day.,(A) True (B) False,B,"Do you know why you are supposed to eat large predatory fish like tuna infrequently? It is because of the bioaccu- mulation of mercury in those species. Some pollutants remain in an organism throughout its life, a phenomenon called bioaccumulation. In this process, an organism accumulates the entire amount of a toxic compound that it consumes over its lifetime. Not all substances bioaccumulate. Can you name one that does not? Aspirin does not bioaccumulate; if it did, a person would quickly accumulate a toxic amount in her body. Compounds that bioaccumulate are usually stored in the organisms fat. In the sediments, bacteria convert the droplets to the hazardous compound methyl mercury. Bacteria and plankton store all of the mercury from all of the seawater they ingest (Figure 1.2). A small fish that eats bacteria and plankton accumulates all of the mercury from all of the tiny creatures it eats over its lifetime. A big fish accumulates all of the mercury from all of the small fish it eats over its lifetime. For a tuna at the top of the food chain, thats a lot of mercury. Historic increases of mercury in the atmo- sphere: blue is volcanic eruptions; brown, purple, and pink are human-caused. The red region shows the effect of industrial- ization on atmospheric mercury. So tuna pose a health hazard to anything that eats them because their bodies are so high in mercury. This is why the government recommends limits on the amount of tuna that people eat. Limiting intake of large predatory fish is especially important for children and pregnant women. If the mercury just stayed in a persons fat, it would not be harmful, but that fat is used when a woman is pregnant or nursing a baby. A person will also get the mercury into her system when she (or he) burns the fat while losing weight. "
the salts in seawater come from,(A) Rain (B) Evaporation (C) Weathering of rock and soil (D) All of the above,C,"Where does the salt in seawater come from? As water moves through rock and soil on land it picks up ions. This is the flip side of weathering. Salts comprise about 3.5% of the mass of ocean water, but the salt content, or salinity, is different in different locations. What would the salinity be like in an estuary? Where seawater mixes with fresh water, salinity is lower than average. What would the salinity be like where there is lots of evaporation? Where there is lots of evaporation but little circulation of water, salinity can be much higher. The Dead Sea has 30% salinity  nearly nine times the average salinity of ocean water (Figure 1.2). Why do you think this water body is called the Dead Sea? In some areas, dense saltwater and less dense freshwater mix, and they form an immiscible layer, just like oil and water. One such place is a ""cenote"", or underground cave, very common in certain parts of Central America. Ocean water is composed of many sub- stances, many of them salts such as sodium, magnesium, and calcium chlo- ride. Because of the increased salinity, the wa- ter in the Dead Sea is very dense, it has such high salinity that people can easily float in it! "
the salinity is high in water in the great salt lake in utah because,(A) Evaporation rates are high (B) The input of fresh water is low (C) The lake has no outlet to the sea (D) All of the above,D,"The halophiles, which means ""salt-loving,"" live in environments with high levels of salt ( Figure 1.1). They have been identified in the Great Salt Lake in Utah and in the Dead Sea between Israel and Jordan, which have salt concentrations several times that of the oceans. "
chlorine is the most abundant cation in seawater.,(A) True (B) False,B,"Have you ever gone swimming in the ocean? If you have, then you probably tasted the salts in the water. By mass, salts make up about 3.5 percent of ocean water. Figure 14.5 shows the most common minerals in ocean water. The main components are sodium and chloride. Together they form the salt known as sodium chloride. You may know the compound as table salt or the mineral halite. The amount of salts in ocean water varies from place to place. For example, near the mouth of a river, ocean water may be less salty. Thats because river water contains less salt than ocean water. Where the ocean is warm, the water may be more salty. Can you explain why? (Hint: More water evaporates when the water is warm.) "
why might seawater and freshwater not mix?,(A) Saltwater is denser so it sinks (B) Freshwater is denser so it sinks (C) Saltwater is colder so it sinks (D) Freshwater is colder so it sinks,A,"Where does the salt in seawater come from? As water moves through rock and soil on land it picks up ions. This is the flip side of weathering. Salts comprise about 3.5% of the mass of ocean water, but the salt content, or salinity, is different in different locations. What would the salinity be like in an estuary? Where seawater mixes with fresh water, salinity is lower than average. What would the salinity be like where there is lots of evaporation? Where there is lots of evaporation but little circulation of water, salinity can be much higher. The Dead Sea has 30% salinity  nearly nine times the average salinity of ocean water (Figure 1.2). Why do you think this water body is called the Dead Sea? In some areas, dense saltwater and less dense freshwater mix, and they form an immiscible layer, just like oil and water. One such place is a ""cenote"", or underground cave, very common in certain parts of Central America. Ocean water is composed of many sub- stances, many of them salts such as sodium, magnesium, and calcium chlo- ride. Because of the increased salinity, the wa- ter in the Dead Sea is very dense, it has such high salinity that people can easily float in it! "
water density increases when,(A) Salinity decreases (B) Temperature decreases (C) Pressure decreases (D) All of the above,B,"With so many dissolved substances mixed in seawater, what is the density (mass per volume) of seawater relative to fresh water? Water density increases as: salinity increases temperature decreases pressure increases Differences in water density are responsible for deep ocean currents, as will be discussed in the ""Deep Ocean Currents"" concept. Click image to the left or use the URL below. URL: "
conglomerate rocks are made from,(A) Jagged (B) angular rocks (C) b Round rocks (D) c Sand (E) d Clay,B,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
shale is made from,(A) Jagged (B) angular rocks (C) b Round rocks (D) c Sand (E) d Clay,D,"As the easy-to-reach fossil fuel sources are depleted, alternative sources of fossil fuels are increasingly being exploited (Figure 1.2). These include oil shale and tar sands. Oil shale is rock that contains dispersed oil that has not collected in reservoirs. To extract the oil from the shale requires enormous amounts of hot water. Tar sands are rocky materials mixed with very thick oil. The tar is too thick to pump and so tar sands are strip-mined. Hot water and caustic soda are used to separate the oil from the rock. The environmental consequences of mining these fuels, and of fossil fuel use in general, along with the fact that these fuels do not have a limitless supply, are prompting the development of alternative energy sources in some regions. Click image to the left or use the URL below. URL:  A satellite image of an oil-sands mine in Canada. Click image to the left or use the URL below. URL: "
biochemical sedimentary rocks from in oceans or salt lakes.,(A) True (B) False,A,"Rock Conglomerate Breccia Sandstone Siltstone Shale Sediment Size Large Large Sand-sized Silt-sized, smaller than sand Clay-sized, smallest Other Features Rounded Angular When sediments settle out of calmer water, they form horizontal layers. One layer is deposited first, and another layer is deposited on top of it. So each layer is younger than the layer beneath it. When the sediments harden, the layers are preserved. Sedimentary rocks formed by the crystallization of chemical precipitates are called chemical sedimentary rocks. As discussed in the concepts on minerals, dissolved ions in fluids precipitate out of the fluid and settle out, just like the halite in Figure 1.1. The evaporite, halite, on a cobble from the Dead Sea, Israel. Biochemical sedimentary rocks form in the ocean or a salt lake. Living creatures remove ions, such as calcium, magnesium, and potassium, from the water to make shells or soft tissue. When the organism dies, it sinks to the ocean floor to become a biochemical sediment, which may then become compacted and cemented into solid rock (Figure 1.2). Table 1.2 shows some common types of sedimentary rocks. Breccia Clastic Sandstone Clastic Siltstone Clastic Shale Clastic Rock Salt Chemical precipitate Dolostone Chemical precipitate Limestone Bioclastic (sediments from organic materials, or plant or animal re- mains) Coal Organic Click image to the left or use the URL below. URL: "
which of these rocks are not clastic?,(A) Conglomerate (B) Sandstone (C) Coal (D) Shale,C,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
sedimentary rocks in order of particle size from small to large is,(A) Conglomerate or breccia-sandstone-siltstone-shale (B) Shale-siltstone-sandstone-conglomerate or breccia (C) Sandstone-shale-Breccia-siltstone-conglomerate (D) Sandstone-siltstone-shale-conglomerate-breccia,B,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
rock salt is a clastic rock.,(A) True (B) False,B,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
sediments are deposited,(A) Horizontally (B) Vertically (C) As a coating on the land surface (D) All of these,A,"Eventually, the sediment in ocean water is deposited. Deposition occurs where waves and other ocean motions slow. The smallest particles, such as silt and clay, are deposited away from shore. This is where water is calmer. Larger particles are deposited on the beach. This is where waves and other motions are strongest. "
sedimentary rocks are made by,(A) Rock fragments (B) Precipitate from fluids (C) Precipitation from living organisms (D) All of the above,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
which of these rocks forms from chemicals that precipitate from evaporating water?,(A) Rock salt (B) Coal (C) Gypsum (D) Conglomerate,C,"Chemical sedimentary rocks form when crystals precipitate out from a liquid. The mineral halite, also called rock salt, forms this way. You can make halite! Leave a shallow dish of salt water out in the Sun. As the water evaporates, salt crystals form in the dish. There are other chemical sedimentary rocks, like gypsum. Table 4.1 shows some common types of sedimentary rocks and the types of sediments that make them up. Picture Rock Name Conglomerate Type of Sedimentary Rock Clastic Breccia Clastic Sandstone Clastic Siltstone Clastic Limestone Bioclastic Coal Organic Picture Rock Name Rock Salt Type of Sedimentary Rock Chemical precipitate "
sedimentary rocks are classified by,(A) How they form (B) Sediment size (C) Whether they are made from living things (D) All of the above,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
sedimentary rocks are made from,(A) Fragments of other rocks (B) Organic materials (C) Chemical precipitates (D) All of the above,D,"Over time, deposited sediments may harden into rock. First, the sediments are compacted. That is, they are squeezed together by the weight of sediments on top of them. Next, the sediments are cemented together. Minerals fill in the spaces between the loose sediment particles. These cementing minerals come from the water that moves through the sediments. These types of sedimentary rocks are called clastic rocks. Clastic rocks are rock fragments that are compacted and cemented together. Clastic sedimentary rocks are grouped by the size of the sediment they contain. Conglomerate and breccia are made of individual stones that have been cemented together. In conglomerate, the stones are rounded. In breccia, the stones are angular. Sandstone is made of sand-sized particles. Siltstone is made of smaller particles. Silt is smaller than sand but larger than clay. Shale has the smallest grain size. Shale is made mostly of clay-sized particles and hardened mud. "
which describes mechanical weathering?,(A) Precipitation that creates minerals (B) Breaking minerals and rocks into smaller pieces (C) Removal of minerals and rocks by water (D) wind (E) ice or gravity (F) d Dissolution of less stable minerals and rocks,B,"Mechanical weathering (also called physical weathering) breaks rock into smaller pieces. These smaller pieces are just like the bigger rock, but smaller. That means the rock has changed physically without changing its composition. The smaller pieces have the same minerals, in just the same proportions as the original rock. "
darker sediments form when the environment is oxygen rich.,(A) True (B) False,B,"What evidence do scientists have that large quantities of oxygen entered the atmosphere? The iron contained in the rocks combined with the oxygen to form reddish iron oxides. By the beginning of the Proterozoic, banded-iron formations (BIFs) were forming. Banded-iron formations display alternating bands of iron oxide and iron-poor chert that probably represent a seasonal cycle of an aerobic and an anaerobic environment. The oldest BIFs are 3.7 billion years old, but they are very common during the Great Oxygenation Event 2.4 billion years ago (Figure 1.2). By 1.8 billion years ago, the amount of BIF declined. In recent times, the iron in these formations has been mined, and that explains the location of the auto industry in the upper Midwest. "
red rocks are formed when this element is present.,(A) Nitrogen (B) Carbon (C) Silica (D) Oxygen,D,"Magma heats nearby underground water, which reacts with the rocks around it to pick up dissolved particles. As the water flows through open spaces in the rock and cools, it deposits solid minerals. The mineral deposits that form when a mineral fills cracks in rocks are called veins (Figure 1.4). Quartz veins formed in this rock. When minerals are deposited in open spaces, large crystals form (Figure 1.5). Amethyst formed when large crystals grew in open spaces inside the rock. These special rocks are called geodes. "
organic materials are made from the remains of once-living organisms.,(A) True (B) False,A,"We can think about soil as a living resource. Soil is an ecosystem all by itself! Soil is a complex mixture of different materials. Some of them are inorganic. Inorganic materials are made from non-living substances like pebbles and sand. Soil also contains bits of organic materials from plants and animals. In general, about half of the soil is made of pieces of rock and minerals. The other half is organic materials. In the spaces of soil are millions of living organisms. These include earthworms, ants, bacteria, and fungi. In some soils, the organic portion is entirely missing. This is true of desert sand. At the other extreme, a soil may be completely organic. Peat, found in a bog or swamp, is totally organic soil. Organic materials are necessary for a soil to be fertile. The organic portion provides the nutrients needed for strong plant growth. "
"erosion is the process in which sediments are removed and transported by water, wind, ice, or gravity.",(A) True (B) False,A,"Weathering wears rocks at the Earths surface down into smaller pieces. The small fragments are called sediments. Running water, ice, and gravity all transport these sediments from one place to another by erosion. During sedimen- tation, the sediments are laid down or deposited. In order to form a sedimentary rock, the accumulated sediment must become compacted and cemented together. "
streams erode sediments in this way,(A) Larger sediments in mountain areas and smaller sediments in flatter regions (B) Smaller sediments in mountain areas and larger sediments in flatter regions (C) Larger sediments were streams move slowly and smaller sediments where they move rapidly (D) None of the above,A,"Runoff, streams, and rivers carry sediment to the oceans. The sediment in ocean water acts like sandpaper. Over time, they erode the shore. The bigger the waves are and the more sediment they carry, the more erosion they cause. "
landslides dropping large piles of sediment due to,(A) Wind (B) Ice (C) Gravity (D) Water,C,"Landslides are the most dramatic, sudden, and dangerous examples of Earth materials moved by gravity. Landslides are sudden falls of rock; by contrast, avalanches are sudden falls of snow. When large amounts of rock suddenly break loose from a cliff or mountainside, they move quickly and with tremendous force (Figure 1.1). Air trapped under the falling rocks acts as a cushion that keeps the rock from slowing down. Landslides can move as fast as 200 to 300 km/hour. This landslide in California in 2008 blocked Highway 140. Landslides are exceptionally destructive. Homes may be destroyed as hillsides collapse. Landslides can even bury entire villages. Landslides may create lakes when the rocky material dams a stream. If a landslide flows into a lake or bay, they can trigger a tsunami. Landslides often occur on steep slopes in dry or semi-arid climates. The California coastline, with its steep cliffs and years of drought punctuated by seasons of abundant rainfall, is prone to landslides. "
chemical precipitates are made by fragments of other worn down rocks.,(A) True (B) False,B,Sedimentary rocks form in two ways. Particles may be cemented together. Chemicals may precipitate. 
minerals are created when,(A) Water condenses to form halite and other salts (B) Water evaporates and mineral components dissolve (C) Water evaporates and minerals precipitate out (D) None of these,C,"Minerals are made by natural processes. The processes that make minerals happen in or on the Earth. For example, when hot lava cools, mineral crystals form. Minerals also precipitate from water. Some minerals grow when rocks are exposed to high pressures and temperatures. Could something like a mineral be made by a process that was not natural? People make gemstones in a laboratory. Synthetic diamond is a common one. But that stone is not a mineral. It was not formed by a natural process. "
the high point of a wave.,(A) Trough (B) Amplitude (C) Crest (D) Length,C,"Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. "
the height of a wave from the center line to its high point.,(A) Trough (B) Amplitude (C) Crest (D) Length,B,"Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. "
scientists can learn most everything about earths interior by studying the waves that come into one seismograph.,(A) True (B) False,B,The energy from earthquakes travels in waves. The study of seismic waves is known as seismology. Seismologists use seismic waves to learn about earthquakes and also to learn about the Earths interior. One ingenious way scientists learn about Earths interior is by looking at earthquake waves. Seismic waves travel outward in all directions from where the ground breaks and are picked up by seismographs around the world. Two types of seismic waves are most useful for learning about Earths interior. 
the distance between waves from trough to trough is its.,(A) Trough (B) Amplitude (C) Crest (D) Wavelength,F,"Figure 14.9 also shows how the size of waves is measured. The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days. "
s-waves can move through,(A) Solids (B) liquids and gases (C) b Solids and liquids (D) but not gases (E) c Solids (F) but not liquids and gases (G) d Liquids and gases (H) but not solids,C,"P-waves and S-waves are known as body waves because they move through the solid body of the Earth. P-waves travel through solids, liquids, and gases. S-waves only move through solids (Figure 1.2). Surface waves only travel along Earths surface. In an earthquake, body waves produce sharp jolts. They do not do as much damage as surface waves. P-waves (primary waves) are fastest, traveling at about 6 to 7 kilometers (about 4 miles) per second, so they arrive first at the seismometer. P-waves move in a compression/expansion type motion, squeezing and S-waves (secondary waves) are about half as fast as P-waves, traveling at about 3.5 km (2 miles) per second, and arrive second at seismographs. S-waves move in an up and down motion perpendicular to the direction of wave travel. This produces a change in shape for the Earth materials they move through. Only solids resist a change in shape, so S-waves are only able to propagate through solids. S-waves cannot travel through liquid. "
which of these statements is not true about s-waves?,(A) S-waves are secondary waves (B) S-waves move up and down or side to side (C) S-waves cannot travel through liquids (D) S-waves compress and expand,D,"P-waves and S-waves are known as body waves because they move through the solid body of the Earth. P-waves travel through solids, liquids, and gases. S-waves only move through solids (Figure 1.2). Surface waves only travel along Earths surface. In an earthquake, body waves produce sharp jolts. They do not do as much damage as surface waves. P-waves (primary waves) are fastest, traveling at about 6 to 7 kilometers (about 4 miles) per second, so they arrive first at the seismometer. P-waves move in a compression/expansion type motion, squeezing and S-waves (secondary waves) are about half as fast as P-waves, traveling at about 3.5 km (2 miles) per second, and arrive second at seismographs. S-waves move in an up and down motion perpendicular to the direction of wave travel. This produces a change in shape for the Earth materials they move through. Only solids resist a change in shape, so S-waves are only able to propagate through solids. S-waves cannot travel through liquid. "
which of these statements is not true about surface waves?,(A) There are two types of surface waves (B) Surface waves travel through solids (C) liquids and gases (D) c Surface waves travel along the ground (E) d Surface waves are the slowest of all seismic waves,B,"A surface wave is a wave that travels along the surface of a medium. It combines a transverse wave and a longitudinal wave. Ocean waves are surface waves. They travel on the surface of the water between the ocean and the air. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. This is illustrated in Figure 19.8 and at the URL below. MEDIA Click image to the left or use the URL below. URL:  In deep water, particles of water just move in circles. They dont actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. They start to drag on the bottom, creating friction (see Figure 19.9). The friction slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. This causes the waves to get steeper until they topple over and crash on the shore. The crashing waves carry water onto the shore as surf. "
we know that earth has a liquid outer core because,(A) P-waves travel through the core at the same speed they travel through solids (B) S-waves disappear at the core-mantle boundary (C) Surface waves highlight the transition between the liquid outer core and the solid inner core (D) All of these,B,"The dense, iron core forms the center of the Earth. Scientists know that the core is metal from studying metallic meteorites and the Earths density. Seismic waves show that the outer core is liquid, while the inner core is solid. Movement within Earths outer liquid iron core creates Earths magnetic field. These convection currents form in the outer core because the base of the outer core is heated by the even hotter inner core. "
p-waves speed up at the mantle core boundary.,(A) True (B) False,B,"By tracking seismic waves, scientists have learned what makes up the planets interior (Figure 1.4). P-waves slow down at the mantle core boundary, so we know the outer core is less rigid than the mantle. S-waves disappear at the mantle core boundary, so we know the outer core is liquid. "
scientists can learn about earth interior by using seismic waves because:,(A) P-waves go faster in material that is more rigid (B) S-waves do not make it to all seismic stations if they must travel through a liquid (C) P-waves bend slightly when they travel between material types (D) All of these,D,Geologists study earthquake waves to see Earths interior. Waves of energy radiate out from an earthquakes focus. These are called seismic waves (Figure 6.1). Seismic waves change speed as they move through different materials. This causes them to bend. Some seismic waves do not travel through liquids or gases. Scientists use all of this information to understand what makes up the Earths interior. 
"in a normal year, the trade winds blow from __________ near __________.",(A) East to west; the 45th parallel (B) West to eat: the 45th parallel (C) East to west; the Equator (D) West to east; the Equator,C,"In a normal year, the trade winds blow across the Pacific Ocean near the Equator from east to west (toward Asia). A low pressure cell rises above the western equatorial Pacific. Warm water in the western Pacific Ocean raises sea levels by half a meter. Along the western coast of South America, the Peru Current carries cold water northward, and then westward along the Equator with the trade winds. Upwelling brings cold, nutrient-rich waters from the deep sea. "
"in a normal year, the peru current carries cold water north along south america and then across the equator.",(A) True (B) False,A,"In a normal year, the trade winds blow across the Pacific Ocean near the Equator from east to west (toward Asia). A low pressure cell rises above the western equatorial Pacific. Warm water in the western Pacific Ocean raises sea levels by half a meter. Along the western coast of South America, the Peru Current carries cold water northward, and then westward along the Equator with the trade winds. Upwelling brings cold, nutrient-rich waters from the deep sea. "
"in a normal year, along western south america",(A) Upwelling brings cold (B) nutrient-rich water to the surface (C) b Downwelling takes warm (D) nutrient-poor water to the bottom (E) c Surface currents bring warm (F) nutrient rich water from the Equator (G) d None of these,A,"In a normal year, the trade winds blow across the Pacific Ocean near the Equator from east to west (toward Asia). A low pressure cell rises above the western equatorial Pacific. Warm water in the western Pacific Ocean raises sea levels by half a meter. Along the western coast of South America, the Peru Current carries cold water northward, and then westward along the Equator with the trade winds. Upwelling brings cold, nutrient-rich waters from the deep sea. "
the north atlantic oscillation mostly alters climate in europe.,(A) True (B) False,A,"In a La Nia year, as in a normal year, trade winds moves from east to west and warm water piles up in the western Pacific Ocean. Ocean temperatures along coastal South America are colder than normal (instead of warmer, as in El Nio). Cold water reaches farther into the western Pacific than normal. Other important oscillations are smaller and have a local, rather than global, effect. The North Atlantic Oscillation mostly alters climate in Europe. The Mediterranean also goes through cycles, varying between being dry at some times and warm and wet at others. Click image to the left or use the URL below. URL: "
el nio events,(A) Alter rainfall patters so some regions receive much more rain than normal (B) Bring drought to some regions (C) Ordinarily last one to two years (D) All of the above,D,"Youve probably heard of El Nio and La Nia. These terms refer to certain short-term changes in climate. The changes are natural and occur in cycles. To understand the changes, you first need to know what happens in normal years. This is shown in Figure 17.24. "
warm water in the western pacific ocean decreases sea levels.,(A) True (B) False,B,"In a normal year, the trade winds blow across the Pacific Ocean near the Equator from east to west (toward Asia). A low pressure cell rises above the western equatorial Pacific. Warm water in the western Pacific Ocean raises sea levels by half a meter. Along the western coast of South America, the Peru Current carries cold water northward, and then westward along the Equator with the trade winds. Upwelling brings cold, nutrient-rich waters from the deep sea. "
"during el nio,",(A) Downwelling off of South America ends (B) The Trade Winds and surface currents reverse direction (C) Cold water piles up in the eastern Pacific Ocean (D) All of these,B,"In an El Nio year, when water temperature reaches around 28o C (82o F), the trade winds weaken or reverse direction and blow east (toward South America) (Figure 1.2). Warm water is dragged back across the Pacific Ocean and piles up off the west coast of South America. With warm, low-density water at the surface, upwelling stops. Without upwelling, nutrients are scarce and plankton populations decline. Since plankton form the base of the food web, fish cannot find food, and fish numbers decrease as well. All the animals that eat fish, including birds and humans, are affected by the decline in fish. By altering atmospheric and oceanic circulation, El Nio events change global climate patterns. Some regions receive more than average rainfall, including the west coast of North and South America, the southern United States, and Western Europe. Drought occurs in other parts of South America, the western Pacific, southern and northern Africa, and southern Europe. An El Nio cycle lasts one to two years. Often, normal circulation patterns resume. Sometimes circulation patterns bounce back quickly and extremely (Figure 1.3). This is a La Nia. "
"during la nia,",(A) Surface wind and water currents flow in their normal directions (B) Cold water piles up in the western Pacific Ocean (C) Weather patterns mirror the patterns in El Niño (D) All of these,A,La Nia generally follows El Nio. It occurs when the Pacific Ocean is cooler than normal. Figure 17.26 shows what happens. The trade winds are like they are in a normal year. They blow from east to west. But in a La Nia the winds are stronger than usual. More cool water builds up in the western Pacific. These changes can also affect climates worldwide. 
what do el nio events cause to happen off of south america?,(A) A rise in upwelling (B) The pooling of cold (C) nutrient-rich water (D) c A collapse of the food web (E) d All of these,C,"In an El Nio year, when water temperature reaches around 28o C (82o F), the trade winds weaken or reverse direction and blow east (toward South America) (Figure 1.2). Warm water is dragged back across the Pacific Ocean and piles up off the west coast of South America. With warm, low-density water at the surface, upwelling stops. Without upwelling, nutrients are scarce and plankton populations decline. Since plankton form the base of the food web, fish cannot find food, and fish numbers decrease as well. All the animals that eat fish, including birds and humans, are affected by the decline in fish. By altering atmospheric and oceanic circulation, El Nio events change global climate patterns. Some regions receive more than average rainfall, including the west coast of North and South America, the southern United States, and Western Europe. Drought occurs in other parts of South America, the western Pacific, southern and northern Africa, and southern Europe. An El Nio cycle lasts one to two years. Often, normal circulation patterns resume. Sometimes circulation patterns bounce back quickly and extremely (Figure 1.3). This is a La Nia. "
el nio and la nia make a cycle called the los nios oscillation.,(A) True (B) False,B,"Youve probably heard of El Nio and La Nia. These terms refer to certain short-term changes in climate. The changes are natural and occur in cycles. To understand the changes, you first need to know what happens in normal years. This is shown in Figure 17.24. "
how is the suns energy important to earth?,(A) The Sun heats the planet (B) It drives the weather (C) It helps plants conduct photosynthesis (D) All of the above,D,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
sensors can detect wavelengths of energy we cant see and convert them to visible light.,(A) True (B) False,A,"Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also depend on visible light, either directly or indirectly. Many animalsincluding predators of jellyfishuse visible light to see. Plants and certain other organisms use visible light to make food in the process of photosynthesis. Without this food, most other organisms would not be able to survive. Q: Do you think that some animals might be able to see light that isnt visible to humans? A: Some animals can see light in the infrared or ultraviolet range of wavelengths. For example, mosquitoes can see infrared light, which is emitted by warm objects. By seeing infrared light, mosquitoes can tell where the warmest, blood-rich areas of the body are located. "
this is the only type of energy humans can see.,(A) X-rays (B) Microwaves (C) Infrared (D) Visible,D,"Energy from the Sun has a wide range of wavelengths. The total range of energy is called the electromagnetic spectrum. You can see it in Figure 15.8. Visible light is the only light that humans can see. Different wavelengths of visible light appear as different colors. Radio waves have the longest wavelengths. They also have the least amount of energy. Infrared light has wavelengths too long for humans to see, but we can feel them as heat. The atmosphere absorbs the infrared light. Ultraviolet (UV) light is in wavelengths too short for humans to see. The most energetic UV light is harmful to life. The atmosphere absorbs most of this UV light from the Sun. Gamma rays have the highest energy and they are the most damaging rays. Fortunately, gamma rays dont penetrate Earths atmosphere. "
"with an infrared camera, a living creature",(A) Is hottest at the top of the head (B) Is hottest around the face (C) Is hottest around the eyes (D) mouth and ears (E) d Is the same temperature all around,C,"Light with the longest wavelengths is called infrared light. The term infrared means ""below red."" Infrared light is the range of light waves that have longer wavelengths than red light in the visible spectrum. You cant see infrared light waves, but you can feel them as heat on your skin. The sun gives off infrared light as do fires and living things. The picture of a cat that opened this chapter was made with a camera that detects infrared light waves and changes their energy to colored light in the visible range. Night vision goggles, which are used by law enforcement and the military, also detect infrared light waves. The goggles convert the invisible waves to visible images. For a deeper understanding of infrared light, watch the video at this URL:  MEDIA Click image to the left or use the URL below. URL: "
a shorter wavelength means the wave has less energy.,(A) True (B) False,B,The wavelength of a wave is related to the waves energy. Short-wavelength waves have more energy than long- wavelength waves of the same amplitude. (Amplitude is a measure of how far particles of the medium move up and down or back and forth when a wave passes through them.) You can see examples of transverse waves with shorter and longer wavelengths in the Figure 1.3. A: Violet light has the greatest energy because it has the shortest wavelength. 
stratospheric ozone filters out incoming,(A) UVC completely (B) most UVB (C) and some UVA (D) b IRC completely (E) most IRB (F) and some IRA (G) c All ultraviolet (H) d Electromagnetic radiation,A,"The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared energy, which we feel as heat. Some of the wavelengths of solar radiation traveling through the atmosphere may be lost because they are absorbed by various gases (Figure 1.2). Ozone completely removes UVC, most UVB, and some UVA from incoming sunlight. O2 , CO2 , and H2 O also filter out some wavelengths. An image of the Sun taken by the SOHO spacecraft. The sensor is picking up only the 17.1 nm wavelength, in the ultraviolet wavelengths. Atmospheric gases filter some wave- lengths of incoming solar energy. Yel- low shows the energy that reaches the top of the atmosphere. Red shows the wavelengths that reach sea level. Ozone filters out the shortest wavelength UV and oxygen filters out most infrared. Click image to the left or use the URL below. URL: "
the highest energy ultraviolet is ___________ and the lowest energy ultraviolet is __________.,(A) UVA; UVC (B) UVC; UVA (C) UVA; UVB (D) UVB; UVC,B,"Of the solar energy that reaches the outer atmosphere, ultraviolet (UV) wavelengths have the greatest energy. Only about 7% of solar radiation is in the UV wavelengths. The three types are: UVC: the highest energy ultraviolet, does not reach the planets surface at all. UVB: the second highest energy, is also mostly stopped in the atmosphere. UVA: the lowest energy, travels through the atmosphere to the ground. "
the only wavelength of energy that are filtered by the atmosphere are uv waves.,(A) True (B) False,B,"The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared energy, which we feel as heat. Some of the wavelengths of solar radiation traveling through the atmosphere may be lost because they are absorbed by various gases (Figure 1.2). Ozone completely removes UVC, most UVB, and some UVA from incoming sunlight. O2 , CO2 , and H2 O also filter out some wavelengths. An image of the Sun taken by the SOHO spacecraft. The sensor is picking up only the 17.1 nm wavelength, in the ultraviolet wavelengths. Atmospheric gases filter some wave- lengths of incoming solar energy. Yel- low shows the energy that reaches the top of the atmosphere. Red shows the wavelengths that reach sea level. Ozone filters out the shortest wavelength UV and oxygen filters out most infrared. Click image to the left or use the URL below. URL: "
oxygen in the atmosphere filters out,(A) Red waves of visible light (B) The shortest wavelength ultraviolet (C) Infrared (D) The longest wavelength ultraviolet,C,"The remaining solar radiation is the longest wavelength, infrared. Most objects radiate infrared energy, which we feel as heat. Some of the wavelengths of solar radiation traveling through the atmosphere may be lost because they are absorbed by various gases (Figure 1.2). Ozone completely removes UVC, most UVB, and some UVA from incoming sunlight. O2 , CO2 , and H2 O also filter out some wavelengths. An image of the Sun taken by the SOHO spacecraft. The sensor is picking up only the 17.1 nm wavelength, in the ultraviolet wavelengths. Atmospheric gases filter some wave- lengths of incoming solar energy. Yel- low shows the energy that reaches the top of the atmosphere. Red shows the wavelengths that reach sea level. Ozone filters out the shortest wavelength UV and oxygen filters out most infrared. Click image to the left or use the URL below. URL: "
the source of solar power is nuclear,(A) Fission (B) Oxidation (C) Fusion (D) Reduction,C,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
solar energy through the empty space between the sun and earth as ____________.,(A) Darkness (B) Radio waves (C) Heat (D) Radiation,D,"Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Suns energy travels through space by radiation. After sunlight heats the planets surface, some heat radiates back into the atmosphere. "
the sun is the source of energy in,(A) Fossil fuels (B) Nuclear power (C) Geothermal energy (D) None of these,A,"The Sun is Earths main source of energy. The Sun gives us both light and heat. The Sun changes hydrogen into helium through nuclear fusion. This releases huge amounts of energy. The energy travels to the Earth mostly as visible light. The energy is carried through the empty space by radiation. We can use sunlight as an energy resource, called solar energy (Figure 5.7). "
one of the advantages of solar power over traditional energy source is that solar power,(A) Can be harnessed locally (B) Is much less expensive (C) Keeps people in refineries employed (D) All of these,A,"Solar energy has many benefits. It does not produce any pollution. There is plenty of it available, much more than we could possibly use. But solar energy has problems. The Sun doesnt shine at night. A special battery is needed to store extra energy during the day for use at night. The technology for most uses of solar energy is still expensive. Until solar technology becomes more affordable, most people will prefer to get their energy from other sources. "
the southwestern u.s. is a hotspot for solar energy because the region receives a lot of sunlight.,(A) True (B) False,A,"Solar energy has been used on a small scale for hundreds of years. Today we are using solar energy for more of our power demands. Solar power plants are being built in many locations around the world. In the United States, the southwestern deserts are well suited for solar plants. "
"in a solar power plant, the sunlight is focused onto a receiver by a group of",(A) Lenses (B) Slides (C) Mirrors (D) None of these,C,"Sunlight is turned into electricity at a solar power plant. These power plants use a large group of mirrors to focus sunlight on one place. This place is called a receiver (Figure 5.8). At the receiver, a liquid such as oil or water is heated to a high temperature. The liquid transfers its heat by conduction. In conduction, energy moves between two objects that are in contact. The higher temperature object transfers heat to the lower temperature object. For example, when you heat a pot of water on a stove top, energy moves from the pot to its metal handle by conduction. At a solar power plant, the energy conducted by the heated liquid is used to make electricity. "
"in a solar power plant, a liquid flowing through a receiver, is heated by",(A) Conduction (B) Focused sunlight (C) Direct sunlight (D) Convection,B,"Sunlight is turned into electricity at a solar power plant. These power plants use a large group of mirrors to focus sunlight on one place. This place is called a receiver (Figure 5.8). At the receiver, a liquid such as oil or water is heated to a high temperature. The liquid transfers its heat by conduction. In conduction, energy moves between two objects that are in contact. The higher temperature object transfers heat to the lower temperature object. For example, when you heat a pot of water on a stove top, energy moves from the pot to its metal handle by conduction. At a solar power plant, the energy conducted by the heated liquid is used to make electricity. "
heat is transferred from the liquid to a nearby object through the process called,(A) Nuclear power (B) Conduction (C) Production (D) Construction,B,"Convection is the transfer of thermal energy by particles moving through a fluid (either a gas or a liquid). Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Convection is one of three ways that thermal energy can be transferred (the other ways are conduction and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
limitations of solar power is include,(A) The technology is expensive (B) Storing the energy is difficult (C) Solar panels take up a lot of space (D) All of the above,D,"Solar energy has many benefits. It is extremely abundant, widespread, and will never run out. But there are problems with the widespread use of solar power. Sunlight must be present. Solar power is not useful in locations that are often cloudy or dark. However, storage technology is being developed. The technology needed for solar power is still expensive. An increase in interested customers will provide incentive for companies to research and develop new technologies and to figure out how to mass-produce existing technologies (Figure 1.3). Solar panels require a lot of space. Fortunately, solar panels can be placed on any rooftop to supply at least some of the power required for a home or business. This experimental car is one example of the many uses that engineers have found for solar energy. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
"in the future, cars may be able to run on solar energy.",(A) True (B) False,A,"New technologies such as 3-D printers often evolve slowly as new materials, designs, or processes are invented. Solar-powered cars are a good example. For several decades, researchers have been working on developing practical solar-powered cars. Why? Cars powered by sunlight have at least two important advantages over gas-powered cars. The energy they use is free and available almost everywhere, and they produce no pollution. The timeline in Table Milestone 1954: First modern solar cell 1955: First solar car 1983: First practical solar car 1987: First World Solar Challenge 2008: First Commercial solar car The first modern solar cell was invented in 1954 by a team of researchers at Bell Labs in the U.S. It could convert light energy to enough electricity to power devices. In 1955, William G. Cobb of General Motors demon- strated his 15-inch-long Sunmobile, the worlds first solar-powered automobile. Its tiny electric motor was powered by 12 solar cells on top of the car. In 1983, the first drivable solar car was created by Hans Tholstrup, a Danish inventor who was influenced by the earlier Sunmobile. Called the Quiet Achiever, Tholstrups car was driven 4000 km across Australia. However, its average speed was only 23 km/h, despite having more than 700 solar cells on its top panel. Inspired by his success with the Quiet Achiever, in 1987 Tholstrup launched the first World Solar Chal- lenge. This was the worlds first solar car race. The race is now held every other year. In that first race, the winner was General Motors Sunraycer, shown here. It had an average speed of 67 km/h. Its aerodynamic shape helped it achieve that speed. In 2008, the first commercial solar car was introduced. Called the Venturi Astrolab, it has a top speed of 120 km/h. To go this fast while using very little energy, it is built of ultra-light materials. Its oversized body protects the driver in case of collision and provides a lot of surface area for solar cells. Q: Why was the invention of the solar cell important to the evolution of solar car technology? A: The solar car could not exist without the solar cell. This invention provided a way to convert light energy to electricity that could be used to run a device such as a car. Q: The 1955 Sunmobile was just a model car. It was too small for people to drive. Why was it an important achievement in the evolution of solar car technology? A: The car wasnt practical, but it was a working solar car. It showed people that solar car technology is possible. It spurred others, including Hans Tholstrup, to work on solar cars that people could actually drive. Q: How have the World Solar Challenge races influenced the development of solar cars? A: The races have drawn a lot of attention to solar car development. The challenge of winning a race has also stimulated developers to keep improving the performance of solar cars so they can go faster and farther on solar power alone. "
orions belt consists of stars that are different colors.,(A) True (B) False,A,Stars shine in many different colors. The color relates to a stars temperature and often its size. 
"betelgeuse, in the upper left of orions belt, is a ____________.",(A) Bright (B) blue (C) very hot star (D) b Yellow star like our sun (E) c Bright (F) red (G) fairly cool star (H) d White dwarf,C,"The Van Allen radiation belts are two doughnut-shaped zones of highly charged particles that are located very high the atmosphere in the magnetosphere. The particles originate in solar flares and fly to Earth on the solar wind. Once trapped by Earths magnetic field, they follow along the fields magnetic lines of force. These lines extend from above the Equator to the North Pole and also to the South Pole, then return to the Equator. "
extremely high temperature stars are __________.,(A) Red (B) Orange (C) Yellow (D) Blue,D,"A more massive star ends its life in a more dramatic way. Very massive stars become red supergiants, like Betelgeuse. In a red supergiant, fusion does not stop. Lighter atoms fuse into heavier atoms. Eventually iron atoms form. When there is nothing left to fuse, the stars iron core explodes violently. This is called a supernova explosion. The incredible energy released fuses heavy atoms together. Gold, silver, uranium and the other heavy elements can only form in a supernova explosion. A supernova can shine as brightly as an entire galaxy, but only for a short time, as shown in Figure 26.3. "
class m stars are ________.,(A) Red (B) Orange (C) Yellow (D) Blue,A,"We could say that stars are born, change over time, and eventually die. Most stars change in size, color, and class at least once during their lifetime. "
stars are classified primarily by their,(A) Size (B) Temperature (C) Distance (D) Color,D,"Color is the most common way to classify stars. Table 1.1 shows the classification system. The class of a star is given by a letter. Each letter corresponds to a color, and also to a range of temperatures. Note that these letters dont match the color names; they are left over from an older system that is no longer used. Class O B A F G K M Color Blue Blue-white White Yellowish-white Yellow Orange Red Temperature Range 30,000 K or more 10,000-30,000 K 7,500-10,000 K 6,000-7,500 K 5,500-6,000 K 3,500-5,000 K 2,000-3,500 K Sample Star Zeta Ophiuchi Rigel Altair Procyon A Sun Epsilon Indi Betelgeuse, Proxima Cen- tauri For most stars, surface temperature is also related to size. Bigger stars produce more energy, so their surfaces are hotter. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
our sun is a ________.,(A) Yellow star (B) Blue star (C) Orange star (D) Red star,A,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
"the brighter the star, the larger it is.",(A) True (B) False,A,Stars shine in many different colors. The color relates to a stars temperature and often its size. 
the main sequence stars,(A) Are white dwarfs (B) Range from large (C) blue to small (D) red (E) c Range from white to red supergiants (F) d Include all the stars in the universe,B,"For most of a stars life, hydrogen atoms fuse to form helium atoms. A star like this is a main sequence star. The hotter a main sequence star is, the brighter it is. A star remains on the main sequence as long as it is fusing hydrogen to form helium. Our Sun has been a main sequence star for about 5 billion years. As a medium-sized star, it will continue to shine for about 5 billion more years. Large stars burn through their supply of hydrogen very quickly. These stars live fast and die young! A very large star may only be on the main sequence for 10 million years. A very small star may be on the main sequence for tens to hundreds of billions of years. "
the hertzsprung-russell diagram shows _____________________.,(A) The distance and temperature of a star (B) The temperature and classification of a star (C) The brightness and temperature of a star (D) The distance and brightness of a star,C,"The Hertzsprung-Russell diagram (often referred to as the H-R diagram) is a scatter graph that shows various classes of stars in the context of properties such as their luminosity, absolute magnitude, color, and effective temperature. Created around 1910 by Ejnar Hertzsprung and Henry Norris Russell, the diagram provided a great help in understanding stellar evolution. There are several forms of the Hertzsprung-Russell diagram, and the nomenclature is not very well defined. The original diagram displayed the spectral type of stars on the horizontal axis and the absolute magnitude on the vertical axis. The form below shows Kelvin temperature along the horizontal axis going from high temperature on the left to low temperature on the right and luminosity on the vertical axis. We can think of the luminosity as brightness in multiples of the Sun. A luminosity of 100 on the axis would mean 100 times as bright as the Sun. Most of the stars occupy a region in the diagram along a line called the Main Sequence. During that stage, stars are fusing hydrogen into helium in their cores. The position of the Sun in the main sequence is shown in the diagram. You should note that the axial scales for this diagram are not linear. The vertical scale is logarithmic, each line is 100 times greater than the previous line. On the horizontal axis, as we move to the right, the temperature reduces by between 1,000 and 10,000 degrees K between each line. If all other factors were the same, the highest temperature stars would also be the most luminous (the brightest). In the main sequence of stars, we see that as the temperature increases to the left, the luminosity also increases, demonstrating that the hottest stars in this grouping are also the brightest. There are stars, however, that are less bright than their temperature would predict. This group of stars is called white dwarfs. These stars are less bright than expected because of their very small size. These dwarf stars are only one one-thousandth the size of stars in the main sequence. There are also stars that are much brighter than their temperature would predict. This group of stars are called red giants. They are brighter than their temperature would predict because they are much larger than stars in the main sequence. These stars have expanded to several thousand times the size of stars in the main sequence. Stars that are reddish in color are cooler than other stars while stars that are bluish in color are hotter than other stars. A white dwarf is a stellar remnant that is very dense. A white dwarfs mass is comparable to the Sun and its volume is comparable to that of Earth. The very low brightness of a white dwarf comes from the emission of stored heat energy. White dwarfs are thought to be the final evolutionary state of any star whose mass is not great enough to become a neutron star. Approximately 97% of the stars in our galaxy will become neutron stars. After the hydrogen-fusing lifetime of a main-sequence star of low or medium mass ends, it will expand to a red giant which fuses helium to carbon and oxygen in its core. If a red giant has insufficient mass to generate the core temperatures required to fuse carbon, around 1 billion K, an inert mass of carbon and oxygen will build up at its center. After blowing off its outer layers to form a planetary nebula, the core will be left behind to form the remnant white dwarf. White dwarfs are composed of carbon and oxygen. A white dwarf is very hot when it is formed, but since it has no source of energy (no further fusion reactions), it will gradually radiate away its energy and cool down. Over a very long time, a white dwarf will cool to temperatures at which it will no longer emit significant light, and it will become a cold black dwarf. A red giant star is a star with a mass like the Sun that is in the last phase of its life, when Hydrogen fusion reactions in the core decrease due to the lack of fuel. With the gravitational collapse of the core, the fusion reactions now occur in a shell surrounding the core. The outer layer of the star expands enormously up to 1000 times the size of the Sun. When the Sun becomes a red giant, its volume will include the orbit of Mercury and Venus and maybe even Earth. The increased size increases the luminosity even though the outer layer cools to only 3000 K or so. The cooler outer layer causes it to be a red star. After a few more million years, the star evolves into a white dwarf-planetary nebula system. "
"the brightest stars are more than 10,000 times brighter than the sun.",(A) True (B) False,A,"When you look at the sky on a clear night, you can see dozens, perhaps even hundreds, of tiny points of light. Almost every one of these points of light is a star, a giant ball of glowing gas at a very, very high temperature. Stars differ in size, temperature, and age, but they all appear to be made up of the same elements and to behave according to the same principles. "
this ancient civilization created the zodiac.,(A) Mayan (B) Aztecs (C) Babylonian (D) Indus,C,"The Astronomy of the ancient Greeks was linked to mathematics, and Greek astronomers sought to create geomet- rical models that could imitate the appearance of celestial motions. This tradition originated around the 6th century BCE, with the followers of the mathematician Pythagoras (~580 - 500 BCE). Pythagoras believed that everything was related to mathematics and that through mathematics everything could be predicted and measured in rhythmic patterns or cycles. He placed astronomy as one of the four mathematical arts, the others being arithmetic, geometry and music. While best known for the Pythagorean Theorem, Pythagoras did have some input into astronomy. By the time of Pythagoras, the five planets visible to the naked eye - Mercury, Venus, Mars, Jupiter and Saturn - had long been identified. The names of these planets were initially derived from Greek mythology before being given the equivalent Roman mythological names, which are the ones we still use today. The word planet is a Greek term meaning wanderer, as these bodies move across the sky at different speeds from the stars, which appear fixed in the same positions relative to each other. For part of the year Venus appears in the eastern sky as an early morning object before disappearing and reappearing a few weeks later in the evening western sky. Early Greek astronomers thought this was two different bodies and assigned the names Phosphorus and Hesperus to the morning and evening apparitions respectively. Pythagoras is given credit for being the first to realize that these two bodies were in fact the same planet, a notion he arrived at through observation and geometrical calculations. Pythagoras was also one of the first to think that the Earth was round, a theory that was finally proved around 330 BCE by Aristotle. (Although, as you are probably aware, many people in 1642 CE still believed the earth to be flat.) Aristotle (384 BCE - 322 BCE) demonstrates in his writings that he knew we see the moon by the light of the sun, how the phases of the moon occur, and understood how eclipses work. He also knew that the earth was a sphere. Philosophically, he argued that each part of the earth is trying to be pulled to the center of the earth, and so the earth would naturally take on a spherical shape. He then pointed out observations that support the idea of a spherical earth. First, the shadow of the earth on the moon during a lunar eclipse is always circular. The only shape that always casts a circular shadow is a sphere. Second, as one traveles more north or south, the positions of the stars in the sky change. There are constellations visible in the north that one cannot see in the south and vice versa. He related this to the curvature of the earth. Aristotle talked about the work of earlier Greeks, who had developed an earth centered model of the planets. In these models, the center of the earth is the center of all the other motions. While it is not sure if the earlier Greeks actually thought the planets moved in circles, it is clear that Aristotle did. Aristotle rejected a moving earth for two reasons. Most importantly he didnt understand inertia. To Aristotle, the natural state for an object was to be at rest. He believed that it takes a force in order for an object to move. Using Aristotles ideas, if the earth were moving through space, if you tripped, you would not be in contact with the earth, and so would get left behind in space. Since this obviously does not happen, the earth must not move. This misunderstanding of inertia confused scientists until the time of Galileo. A second, but not as important, reason Aristotle rejected a moving earth is that he recognized that if the earth moved and rotated around the sun, there would be an observable parallax of the stars. One cannot see stellar parallax with the naked-eye, so Aristotle concluded that the earth must be at rest. (The stars are so far away, that one needs a good telescope to measure stellar parallax, which was first measured in 1838.) Aristotle believed that the objects in the heavens are perfect and unchanging. Since he believed that the only eternal motion is circular with a constant speed, the motions of the planets must be circular. This came to be called The Principal of Uniform Circular Motion. Aristotle and his ideas became very important because they became incorporated into the Catholic Churchs theology in the twelfth century by Thomas Aquinas. In the early 16th century, the Church banned new interpretations of scripture and this included a ban on ideas of a moving earth. Claudius Ptolemy (90 - 168 CE) was a citizen of Egypt which was under Roman rule during Ptolemys lifetime. During his lifetime he was a mathematician, astronomer, and geographer. His theories dominated the worlds understanding of astronomy for over a thousand years. While it is known that many astronomers published works during this time, only Ptolemys work The Almagest survived. In it, he outlined his geometrical reasoning for a geocentric view of the Universe. As outlined in the Almagest, the Universe according to Ptolemy was based on five main points: 1) the celestial realm is spherical, 2) the celestial realm moves in a circle, 3) the earth is a sphere, 4) the celestial realm orbit is a circle centered on the earth, and 5) earth does not move. Ptolemy also identified eight circular orbits surrounding earth where the other planets existed. In order, they were the moon, Mercury, Venus, the Sun, Mars, Jupiter, Saturn, and the sphere of fixed stars. A serious problem with the earth-centered system was the fact that at certain times in their orbits, some of the planets appeared to move in the opposite direction of their normal movement. This reverse direction movement is referred to as retrograde motion. If the earth was to remain motionless at the center of the system, some very intricate designs were necessary to explain the movement of the retrograde planets. In the Ptolemaic system, each retrograde planet moved by two spheres. The Ptolemaic system had circles within circles that produced epicycles. In the sketch above on the left, the red ball moved clockwise in its little circle while the entire orbit also orbited clockwise around the big circle. This process produced a path like that shown in the sketch above on the right. As the red ball moved around its path, at some times it would be moving clockwise and then for a short period, it would move counterclockwise. This motion was able to explain the retrograde motion noted for some planets. "
stars are,(A) Giant balls of high temperature (B) glowing gas (C) b All the same size (D) temperature and age (E) c Objects that do not conform to a single set of principles (F) d All of the above,A,"When you look at the sky on a clear night, you can see dozens, perhaps even hundreds, of tiny points of light. Almost every one of these points of light is a star, a giant ball of glowing gas at a very, very high temperature. Stars differ in size, temperature, and age, but they all appear to be made up of the same elements and to behave according to the same principles. "
"stars in a constellation appear close together, but most are not at all close together in space.",(A) True (B) False,A,"Although the stars in a constellation appear close together as we see them in our night sky, they are not at all close together out in space. In the constellation Orion, the stars visible to the naked eye are at distances ranging from just 26 light-years (which is relatively close to Earth) to several thousand light-years away. Click image to the left or use the URL below. URL: "
why do stars move across the sky each night?,(A) The stars are all moving through from east to west relative to the Earth (B) Earth is rotating on its axis (C) The universe is expanding due to the Big Bang (D) All of the above,B,"Humans have been studying the night sky for thousands of years. Knowing the motions of stars helped people keep track of seasons. With this information they could know when to plant crops. Stars were so important that the patterns they made in the sky were named. These patterns are called constellations. Even now, constellations help astronomers know where they are looking in the night sky. The ancient Greeks carefully observed the locations of stars in the sky. They noticed that some of the stars moved across the background of other stars. They called these bright spots in the sky planets. The word in Greek means wanderers. Today we know that the planets are not stars. They are objects in the solar system that orbit the Sun. Ancient astronomers made all of their observations without the aid of a telescope. "
babylonian astronomers created the zodiac to explain natural phenomena that we can now explain with science.,(A) True (B) False,A,"Humans have been studying the night sky for thousands of years. Knowing the motions of stars helped people keep track of seasons. With this information they could know when to plant crops. Stars were so important that the patterns they made in the sky were named. These patterns are called constellations. Even now, constellations help astronomers know where they are looking in the night sky. The ancient Greeks carefully observed the locations of stars in the sky. They noticed that some of the stars moved across the background of other stars. They called these bright spots in the sky planets. The word in Greek means wanderers. Today we know that the planets are not stars. They are objects in the solar system that orbit the Sun. Ancient astronomers made all of their observations without the aid of a telescope. "
"the alignment of stars in the sky, particularly the patterns of the constellations when a person is born, affects events on earth.",(A) True (B) False,B,"There is no reason to think that the alignment of the stars has anything to do with events that happen on Earth. The constellations were defined by people who noticed that patterns could be made from stars, but the patterns do not reflect any characteristics of the stars themselves. When scientific tests are done to provide evidence in support of astrological ideas, the tests fail. When a scientific idea fails, it is abandoned or modified. Astrologers do not change or abandon their ideas. Click image to the left or use the URL below. URL: "
asterisms are,(A) Groups of stars that formed together and stay in the same patterns (B) Patterns of stars that appear the same way from Earth (C) Patterns of stars that change configuration seasonally (D) None of the above,B,"When you look at the sky on a clear night, you can see dozens, perhaps even hundreds, of tiny points of light. Almost every one of these points of light is a star, a giant ball of glowing gas at a very, very high temperature. Stars differ in size, temperature, and age, but they all appear to be made up of the same elements and to behave according to the same principles. "
"in winter and in summer, people in a given location see",(A) The same constellations (B) Only a few constellations (C) Different constellations (D) None of these,C,"A common misconception is that the Sun is closer to Earth in the summer and farther away from it during the winter. Instead, the seasons are caused by the 23.5o tilt of Earths axis of rotation relative to its plane of orbit around the Sun (Figure 1.1). Solstice refers to the position of the Sun when it is closest to one of the poles. At summer solstice, June 21 or 22, Earths axis points toward the Sun and so the Sun is directly overhead at its furthest north point of the year, the Tropic of Cancer (23.5o N). During the summer, areas north of the Equator experience longer days and shorter nights. In the Southern Hemi- sphere, the Sun is as far away as it will be and so it is their winter. Locations will have longer nights and shorter days. The opposite occurs on winter solstice, which begins on December 21. More about seasons can be found in the Atmospheric Processes chapter. "
"when an idea in astrology fails, it is altered or abandoned to fit the new data.",(A) True (B) False,B,"There is no reason to think that the alignment of the stars has anything to do with events that happen on Earth. The constellations were defined by people who noticed that patterns could be made from stars, but the patterns do not reflect any characteristics of the stars themselves. When scientific tests are done to provide evidence in support of astrological ideas, the tests fail. When a scientific idea fails, it is abandoned or modified. Astrologers do not change or abandon their ideas. Click image to the left or use the URL below. URL: "
only a few stars are made of hydrogen and helium; most are made of heavier elements.,(A) True (B) False,B,"Stars are made mostly of hydrogen and helium, which are packed so densely in a star that in the stars center the pressure is great enough to initiate nuclear fusion reactions. In a nuclear fusion reaction, the nuclei of two atoms combine to create a new atom. Most commonly, in the core of a star, two hydrogen atoms fuse to become a helium atom. Although nuclear fusion reactions require a lot of energy to get started, once they are going they produce enormous amounts of energy (Figure 1.1). In a star, the energy from fusion reactions in the core pushes outward to balance the inward pull of gravity. This energy moves outward through the layers of the star until it finally reaches the stars outer surface. The outer layer of the star glows brightly, sending the energy out into space as electromagnetic radiation, including visible light, heat, ultraviolet light, and radio waves (Figure 1.2). "
a thermonuclear bomb,(A) Is an uncontrolled fission reaction (B) Is a controlled fission reaction (C) Is an uncontrolled fusion reaction (D) Is a controlled fusion reaction,C,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
which type of energy does a star emit?,(A) Visible light (B) Ultraviolet light (C) Radio waves (D) All of the above,D,"Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). "
there is only one particle accelerator for scientists to use.,(A) True (B) False,B,"Scientists have built machines called particle accelerators. These amazing tools smash particles that are smaller than atoms into each other head-on. This creates new particles. Scientists use particle accelerators to learn about nuclear fusion in stars. They can also learn about how atoms came together in the early universe. Two well-known accelerators are SLAC, in California, and CERN, in Switzerland. "
this keeps a star from collapsing from its own gravity.,(A) The energy from fusion (B) Centrifugal force (C) Anti-gravity (D) None of these,A,"You are already very familiar with Earths gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects above the surface, from meteors to skydivers, down to the ground. Gravity between Earth and the moon and between Earth and artificial satellites keeps all these objects circling around Earth. Gravity also keeps Earth moving around the sun. "
the core of a star like the sun is so hot that nuclear fusion takes place.,(A) True (B) False,A,"Stars shine because of nuclear fusion. Fusion reactions in the Suns core keep our nearest star burning. Stars are made mostly of hydrogen and helium. Both are very lightweight gases. A star contains so much hydrogen and helium that the weight of these gases is enormous. The pressure at the center of a star is great enough to heat the gases. This causes nuclear fusion reactions. A nuclear fusion reaction is named that because the nuclei (center) of two atoms fuse (join) together. In stars like our Sun, two hydrogen atoms join together to create a helium atom. Nuclear fusion reactions need a lot of energy to get started. Once they begin, they produce even more energy. "
fusion is ____________.,(A) The splitting of one atom to create two new atoms (B) The combining of atoms to create a new atom (C) The creation of heavy elements from light elements (D) None of these,B,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
the sun produces more energy than most stars.,(A) True (B) False,B,"Only a tiny bit of the Suns light reaches Earth. But that light supplies most of the energy at the surface. The Sun is just an ordinary star, but it appears much bigger and brighter than any of the other stars. Of course, this is just because it is very close. Some other stars produce much more energy than the Sun. How do stars generate so much energy? "
a particle accelerator,(A) Creates conditions in which subatomic particles split apart (B) Creates conditions in which nuclear fission happens (C) Boosts subatomic particles to extremely high energy levels (D) All of these,C,"Scientists have built machines called particle accelerators. These amazing tools smash particles that are smaller than atoms into each other head-on. This creates new particles. Scientists use particle accelerators to learn about nuclear fusion in stars. They can also learn about how atoms came together in the early universe. Two well-known accelerators are SLAC, in California, and CERN, in Switzerland. "
scientists use particle accelerators to study conditions in,(A) The cores of stars (B) The first few minutes of the early universe (C) Which hydrogen fuses to produce helium (D) All of these,D,"Scientists have built machines called particle accelerators. These amazing tools smash particles that are smaller than atoms into each other head-on. This creates new particles. Scientists use particle accelerators to learn about nuclear fusion in stars. They can also learn about how atoms came together in the early universe. Two well-known accelerators are SLAC, in California, and CERN, in Switzerland. "
what is a polar molecule?,(A) A molecule with a slightly imbalanced electrical charge (B) A molecule that is slightly positively charged (C) A molecule that is slightly negatively charged (D) A molecule that is colder than other molecules,A,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
water molecules have this kind of charge.,(A) Negative (B) In between (C) Positive (D) No charge,D,"Water is simply two atoms of hydrogen and one atom of oxygen bonded together (Figure 1.1). The hydrogen ions are on one side of the oxygen ion, making water a polar molecule. This means that one side, the side with the hydrogen ions, has a slightly positive electrical charge. The other side, the side without the hydrogen ions, has a slightly negative charge. Despite its simplicity, water has remarkable properties. Water expands when it freezes, has high surface tension (because of the polar nature of the molecules, they tend to stick together), and others. Without water, life might not be able to exist on Earth and it certainly would not have the tremendous complexity and diversity that we see. "
"when water freezes, water can do this.",(A) Changes to the liquid state (B) Expands (C) Contracts (D) Evaporates,B,"Rocks can break apart into smaller pieces in many ways. Ice wedging is common where water goes above and below its freezing point (Figure 9.2). This can happen in winter in the mid-latitudes or in colder climates in summer. Ice wedging is common in mountainous regions. This is how ice wedging works. When liquid water changes into solid ice, it increases in volume. You see this when you fill an ice cube tray with water and put it in the freezer. The ice cubes go to a higher level in the tray than the water. You also may have seen this if you put a can of soda into the freezer so that it cools down quickly. If you leave the can in the freezer too long, the liquid expands so much that it bends or pops the can. (For the record, water is very unusual. Most substances get smaller when they change from a liquid to a solid.) "
hydrogen atoms have this kind of charge.,(A) Negative (B) In between (C) Positive (D) No charge,C,"All protons are identical. For example, hydrogen protons are exactly the same as protons of helium and all other elements, or pure substances. However, atoms of different elements have different numbers of protons. In fact, atoms of any given element have a unique number of protons that is different from the numbers of protons of all other elements. For example, a hydrogen atom has just one proton, whereas a helium atom has two protons. The number of protons in an atom determines the electrical charge of the nucleus. The nucleus also contains neutrons, but they are neutral in charge. The one proton in a hydrogen nucleus, for example, gives it a charge of +1, and the two protons in a helium nucleus give it a charge of +2. "
why does water have high surface tension?,(A) The polar molecules stick together (B) positive side to negative side (C) b The water molecule is very tightly bound (D) hydrogens to oxygen (E) c The water droplet sends a glue-like substance to its surface (F) d Hydrogen and oxygen do cross-bonding (G) which makes them stick together more,A,"Two unique properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like the water droplet that has formed on the leaky faucet pictured in the Figure 1.2. Water drips from a leaky faucet. Viscosity is a liquids resistance to flowing. You can think of it as friction between particles of liquid. Thicker liquids are more viscous than thinner liquids. For example, the honey pictured in the Figure 1.3 is more viscous than the vinegar. Q: Which liquid do you think is more viscous: honey or chocolate syrup? "
which of these is a special property of water?,(A) Water molecules can stick together (B) Water has a high surface tension (C) Expands when it freezes (D) All of the above,D,"In addition to these properties, other physical properties of matter include the state of matter. States of matter include liquid, solid, and gaseous states. For example at 20 C, coal exists as a solid and water exists as a liquid. Additional examples of physical properties include: odor boiling point ability to conduct heat ability to conduct electricity ability to dissolve in other substances Some of these properties are illustrated in the Figures 1.1, 1.2, 1.3, and 1.4. Click image to the left or use the URL below. URL:  The strong smell of swimming pool water is the odor of chlorine, which is added to the water to kill germs and algae. In con- trast, bottled spring water, which contains no chlorine, does not have an odor. Coolant is added to the water in a car radiator to keep the water from boiling and evaporating. Coolant has a higher boiling point than water and adding it to the water increases the boiling point of the solution. Q: The coolant that is added to a car radiator also has a lower freezing point than water. Why is this physical property useful? A: When coolant is added to water in a car radiator, it lowers the freezing point of the water. This prevents the water in the radiator from freezing when the temperature drops below 0 C, which is the freezing point of pure water. Q: Besides being able to conduct electricity, what other physical property of copper makes it well suited for electric wires? A: Copper, like other metals, is ductile. This means that it can be rolled and stretched into long thin shapes such as wires. This teakettle is made of aluminum except for its handle, which is made of plastic. Aluminum is a good conductor of heat. It conducts heat from the flames on the range to the water inside the kettle, so the water heats quickly. Plastic, on the other hand, is not a good conductor of heat. It stays cool enough to touch even when the rest of the teakettle becomes very hot. "
all three phases of water can be present in a single location.,(A) True (B) False,A,"Water is the only substance on Earth that is present in all three states of matter - as a solid, liquid or gas. (And Earth is the only planet where water is abundantly present in all three states.) Because of the ranges in temperature in specific locations around the planet, all three phases may be present in a single location or in a region. The three phases are solid (ice or snow), liquid (water), and gas (water vapor). See ice, water, and clouds (Figure 1.2). (a) Ice floating in the sea. Can you find all three phases of water in this image? (b) Liquid water. (c) Water vapor is invisible, but clouds that form when water vapor condenses are not. Click image to the left or use the URL below. URL: "
earth is not the only planet that has water in all three states and water is the only substance that is found on earth in all three states.,(A) True (B) False,A,"Water is the only substance on Earth that is present in all three states of matter - as a solid, liquid or gas. (And Earth is the only planet where water is abundantly present in all three states.) Because of the ranges in temperature in specific locations around the planet, all three phases may be present in a single location or in a region. The three phases are solid (ice or snow), liquid (water), and gas (water vapor). See ice, water, and clouds (Figure 1.2). (a) Ice floating in the sea. Can you find all three phases of water in this image? (b) Liquid water. (c) Water vapor is invisible, but clouds that form when water vapor condenses are not. Click image to the left or use the URL below. URL: "
the three states of matter for water are,(A) Ice (B) snow and liquid (C) b Ice (D) liquid water and water vapor (E) c Solid (F) liquid and snow (G) d Snow (H) solid water and gas,B,"Water is the only substance on Earth that is present in all three states of matter - as a solid, liquid or gas. (And Earth is the only planet where water is abundantly present in all three states.) Because of the ranges in temperature in specific locations around the planet, all three phases may be present in a single location or in a region. The three phases are solid (ice or snow), liquid (water), and gas (water vapor). See ice, water, and clouds (Figure 1.2). (a) Ice floating in the sea. Can you find all three phases of water in this image? (b) Liquid water. (c) Water vapor is invisible, but clouds that form when water vapor condenses are not. Click image to the left or use the URL below. URL: "
as air rises,(A) it becomes less dense (B) it becomes warmer (C) the molecules move more freely (D) All of the above,D,"Why does warm air rise (Figure 1.1)? Gas molecules are able to move freely, and if they are uncontained, as they are in the atmosphere, they can take up more or less space. When gas molecules are cool, they are sluggish and do not take up as much space. With the same number of molecules in less space, both air density and air pressure are higher. When gas molecules are warm, they move vigorously and take up more space. Air density and air pressure are lower. Warmer, lighter air is more buoyant than the cooler air above it, so it rises. The cooler air then sinks down, because it is denser than the air beneath it. This is convection, which was described in the chapter Plate Tectonics. "
an ozone molecule is created when,(A) One oxygen atom combines with one oxygen molecule (B) Two oxygen molecules combine (C) Two oxygen atoms combine (D) Two oxygen atoms combine with two oxygen molecules,A,"Ozone is a molecule composed of three oxygen atoms, (O3 ). Ozone in the upper atmosphere absorbs high-energy ultraviolet (UV) radiation coming from the Sun. This protects living things on Earths surface from the Suns most harmful rays. Without ozone for protection, only the simplest life forms would be able to live on Earth. The highest concentration of ozone is in the ozone layer in the lower stratosphere. "
there is a lot of mixing between the stratosphere and troposphere.,(A) True (B) False,B,"There is little mixing between the stratosphere, the layer above the troposphere, and the troposphere below it. The two layers are quite separate. Sometimes ash and gas from a large volcanic eruption may burst into the stratosphere. Once in the stratosphere, it remains suspended there for many years because there is so little mixing between the two layers. "
what is the heat source for the stratosphere?,(A) Earth’s surface (B) Earth’s core (C) The sun (D) None of the above,C,"In the stratosphere, temperature increases with altitude. What is the heat source for the stratosphere? The direct heat source for the stratosphere is the Sun. The ozone layer in the stratosphere absorbs high energy ultraviolet radiation, which breaks the ozone molecule (3-oxygens) apart into an oxygen molecule (2-oxygens) and an oxygen atom (1- oxygen). In the mid-stratosphere there is less UV light and so the oxygen atom and molecule recombine to from ozone. The creation of the ozone molecule releases heat. Because warmer, less dense air sits over cooler, denser air, air in the stratosphere is stable. As a result, there is little mixing of air within the layer. There is also little interaction between the troposphere and stratosphere for this reason. "
the thickness of the ozone layer varies by the season and by _______________.,(A) Latitude (B) Season (C) Altitude (D) A & B,D,"Most ozone loss it taking place over the South Pole and Antarctica. This is the location of the ozone hole. The ozone hole is also seasonal. The hole forms during the early part spring in the Southern Hemisphere and then grows northward. You can see the hole in Figure 22.13. Besides the ozone hole, the ozone layer is thinner over the Northern Hemisphere. "
what is the cycle of ozone in the stratosphere?,(A) UV splits an oxygen molecule into two oxygen atoms (B) which combine with an oxygen molecule to create ozone (C) b An ozone molecule splits into an oxygen molecule and an oxygen atom (D) c An ozone molecule forms from and then splits into two oxygen molecules and two oxygen atoms (E) d A & B,D,"Human-made chemicals are breaking ozone molecules in the ozone layer. Chlorofluorocarbons (CFCs) are the most common, but there are others, including halons, methyl bromide, carbon tetrachloride, and methyl chloroform. CFCs were once widely used because they are cheap, nontoxic, nonflammable, and non-reactive. They were used as spray-can propellants, refrigerants, and in many other products. Once they are released into the air, CFCs float up to the stratosphere. Air currents move them toward the poles. In the winter, they freeze onto nitric acid molecules in polar stratospheric clouds (PSC) (Figure 1.2). In the spring, (1) Solar energy breaks apart oxygen molecules into two oxygen atoms. (2) Ozone forms when oxygen atoms bond together as O3 . UV rays break apart the ozone molecules into one oxygen molecule (O2 ) and one oxygen atom (O). These processes convert UV radiation into heat, which is how the Sun heats the stratosphere. (3) Under natural cir- cumstances, the amount of ozone cre- ated equals the amount destroyed. When O3 interacts with chlorine or some other gases the O3 breaks down into O2 and O and so the ozone layer loses its ability to filter out UV. the Suns warmth starts the air moving, and ultraviolet light breaks the CFCs apart. The chlorine atom floats away and attaches to one of the oxygen atoms on an ozone molecule. The chlorine pulls the oxygen atom away, leaving behind an O2 molecule, which provides no UV protection. The chlorine then releases the oxygen atom and moves on to destroy another ozone molecule. One CFC molecule can destroy as many as 100,000 ozone molecules. PSCs form only where the stratosphere is coldest, and are most common above Antarctica in the wintertime. PSCs are needed for stratospheric ozone to be de- stroyed. "
"during a volcanic eruption, ash and gas may burst into the stratosphere and may remain suspended for many years.",(A) True (B) False,A,"There is little mixing between the stratosphere, the layer above the troposphere, and the troposphere below it. The two layers are quite separate. Sometimes ash and gas from a large volcanic eruption may burst into the stratosphere. Once in the stratosphere, it remains suspended there for many years because there is so little mixing between the two layers. "
why is the ozone layer so important?,(A) It keeps Earth’s atmosphere from becoming too cold (B) It protects life on Earth from high energy ultraviolet radiation (C) It provides oxygen to mountain climbers and people in airplanes (D) It keeps Earth’s atmosphere from becoming too hot,B,Ozone near the ground harms human health. But the ozone layer in the stratosphere protects us from solar rays. Thats why people were alarmed in the 1980s to learn that there was a hole in the ozone layer. 
why do airplanes have their cruising altitude in the stratosphere?,(A) There is less friction (B) There is less turbulence (C) Fuel costs are lower (D) All of the above,D,"Air temperature in the stratosphere layer increases with altitude. Why? The stratosphere gets most of its heat from the Sun. Therefore, its warmer closer to the Sun. The air at the bottom of the stratosphere is cold. The cold air is dense, so it doesnt rise. As a result, there is little mixing of air in this layer. "
why is the air in the stratosphere stable?,(A) Denser air lies above less dense air (B) Cooler air lies above warmer air (C) Warmer air lies above cooler air (D) A & B,C,"Air temperature in the stratosphere layer increases with altitude. Why? The stratosphere gets most of its heat from the Sun. Therefore, its warmer closer to the Sun. The air at the bottom of the stratosphere is cold. The cold air is dense, so it doesnt rise. As a result, there is little mixing of air in this layer. "
"when two streams come together, it is at this.",(A) An influence (B) A confluence (C) A mouth (D) An estuary,B,"A stream originates at its source. A source is likely to be in the high mountains where snows collect in winter and melt in summer, or a source might be a spring. A stream may have more than one source. Two streams come together at a confluence. The smaller of the two streams is a tributary of the larger stream (Figure 1.1). The confluence between the Yellowstone River and one of its tributaries, the Gar- diner River, in Montana. The point at which a stream comes into a large body of water, like an ocean or a lake, is called the mouth. Where the stream meets the ocean or lake is an estuary (Figure 1.2). The mouth of the Klamath River creates an estuary where it flows into the Pacific Ocean in California. The mix of fresh and salt water where a river runs into the ocean creates a diversity of environments where many different types of organisms create unique ecosystems. "
a stream only has one source.,(A) True (B) False,B,"A stream originates at its source. A source is likely to be in the high mountains where snows collect in winter and melt in summer, or a source might be a spring. A stream may have more than one source. Two streams come together at a confluence. The smaller of the two streams is a tributary of the larger stream (Figure 1.1). The confluence between the Yellowstone River and one of its tributaries, the Gar- diner River, in Montana. The point at which a stream comes into a large body of water, like an ocean or a lake, is called the mouth. Where the stream meets the ocean or lake is an estuary (Figure 1.2). The mouth of the Klamath River creates an estuary where it flows into the Pacific Ocean in California. The mix of fresh and salt water where a river runs into the ocean creates a diversity of environments where many different types of organisms create unique ecosystems. "
the mouth of the klamath river and the pacific ocean creates this.,(A) An influence (B) A confluence (C) A mouth (D) An estuary,D,"A stream originates at its source. A source is likely to be in the high mountains where snows collect in winter and melt in summer, or a source might be a spring. A stream may have more than one source. Two streams come together at a confluence. The smaller of the two streams is a tributary of the larger stream (Figure 1.1). The confluence between the Yellowstone River and one of its tributaries, the Gar- diner River, in Montana. The point at which a stream comes into a large body of water, like an ocean or a lake, is called the mouth. Where the stream meets the ocean or lake is an estuary (Figure 1.2). The mouth of the Klamath River creates an estuary where it flows into the Pacific Ocean in California. The mix of fresh and salt water where a river runs into the ocean creates a diversity of environments where many different types of organisms create unique ecosystems. "
base level is,(A) Where a stream meets the sea (B) Where a stream meets a large body of standing water (C) Where a stream touches the base of a mountain range (D) None of these,B,"An accurate location must take into account the third dimension. Elevation is the height above or below sea level. Sea level is the average height of the oceans surface or the midpoint between high and low tide. Sea level is the same all around Earth. Old Faithful is higher above sea level than most locations at 7,349 ft (2240 m). Of course, the highest point on Earth, Mount Everest, is much higher at 29,029 ft (8848 m). "
"a location where a stream forms, often high in the mountains.",(A) A mouth (B) Headwaters (C) Tailwaters (D) Tributary,B,"A stream originates at its source. A source is likely to be in the high mountains where snows collect in winter and melt in summer, or a source might be a spring. A stream may have more than one source. Two streams come together at a confluence. The smaller of the two streams is a tributary of the larger stream (Figure 1.1). The confluence between the Yellowstone River and one of its tributaries, the Gar- diner River, in Montana. The point at which a stream comes into a large body of water, like an ocean or a lake, is called the mouth. Where the stream meets the ocean or lake is an estuary (Figure 1.2). The mouth of the Klamath River creates an estuary where it flows into the Pacific Ocean in California. The mix of fresh and salt water where a river runs into the ocean creates a diversity of environments where many different types of organisms create unique ecosystems. "
the amount of erosion a stream does is,(A) About equal along its length (B) Greater the farther the stream is from its base level (C) Lesser the higher in elevation the stream is (D) Greatest when the stream meanders,B,"Flowing water is a very important agent of erosion. Flowing water can erode rocks and soil. Water dissolves minerals from rocks and carries the ions. This process happens really slowly. But over millions of years, flowing water dissolves massive amounts of rock. Moving water also picks up and carries particles of soil and rock. The ability to erode is affected by the velocity, or speed, of the water. The size of the eroded particles depends on the velocity of the water. Eventually, the water deposits the materials. As water slows, larger particles are deposited. As the water slows even more, smaller particles are deposited. The graph in Figure 10.1 shows how water velocity and particle size influence erosion and deposition. "
"in the united states, water that falls on the west side of the continental divide flows into the pacific ocean and on the east side to the atlantic ocean.",(A) True (B) False,A,"A divide is a topographically high area that separates a landscape into different water basins (Figure 1.6). Rain that falls on the north side of a ridge flows into the northern drainage basin and rain that falls on the south side flows into the southern drainage basin. On a much grander scale, entire continents have divides, known as continental divides. A green floodplain surrounds the Red Rock River as it flows through Montana. (a) The divides of North America. In the Rocky Mountains in Colorado, where does a raindrop falling on the western slope end up? How about on the eastern slope? (b) At Triple Divide Peak in Montana water may flow to the Pacific, the Atlantic, or Hudson Bay depending on where it falls. Can you locate where in the map of North America this peak sits? "
organisms cannot live where a fresh water stream flows into the salty ocean.,(A) True (B) False,B,"When coastal aquifers are overused, salt water from the ocean may enter the aquifer, contaminating the aquifer and making it less useful for drinking and irrigation. Salt water incursion is a problem in developed coastal regions, such as on Hawaii. "
"inland cities were often built on rivers because they provided water, plus",(A) Transportation (B) Waste disposal (C) Defense (D) All of these,D,"People also depend on water as a natural resource. Not content to get water directly from streams or ponds, humans create canals, aqueducts, dams, and wells to collect water and direct it to where they want it (Figure 1.4). Clouds form above the Amazon Rainfor- est even in the dry season because of moisture from plant transpiration. Pont du Gard in France is an ancient aqueduct and bridge that was part of of a well-developed system that supplied wa- ter around the Roman empire. Click image to the left or use the URL below. URL: "
"the central valley of california grows much of the produce in the united states because it has good soil, a mild climate and",(A) Two great rivers that drain the Sierra Nevada Mountains (B) Several large desalination plants that make water from the nearby Pacific Ocean useable (C) Canals from the nearby Colorado River for water (D) None of these,A,"At the same time, many U.S. cities had air pollution problems. Some of the worst were in California. Cars were becoming more popular. Oil refineries and power plants also polluted the air. Mountain ranges trapped polluted air over cities. The California sunshine caused chemical reactions among the pollutants. These reactions produced many more harmful compounds. "
this is the largest supervolcano found in north america.,(A) Pinatubo (B) Helen (C) Mount Shasta (D) Yellowstone,D,"The largest supervolcano in North America is beneath Yellowstone National Park in Wyoming. Yellowstone sits above a hotspot that has erupted catastrophically three times: 2.1 million, 1.3 million, and 640,000 years ago. Yellowstone has produced many smaller (but still enormous) eruptions more recently (Figure 1.2). Fortunately, current activity at Yellowstone is limited to the regions famous geysers. Click image to the left or use the URL below. URL:  The Yellowstone hotspot has produced enormous felsic eruptions. The Yellowstone caldera collapsed in the most recent super eruption. "
a circular shaped hole into which a volcano collapses during an eruption:,(A) Caldera (B) Volcanic neck (C) Batholith (D) Plateau,A,"During a massive eruption all of the material may be ejected from a magma changer. Without support, the mountain above the empty chamber may collapse. This produces a huge caldera. Calderas are generally round, bowl-shaped formations like the picture in Figure 8.18. "
a supervolcano,(A) Is usually mafic in composition (B) Ejects an extremely large magma chamber of material in one huge explosion (C) Has lava and ash layers like a composite volcano (D) All of these,B,"Supervolcanoes are the most dangerous type of volcano. During an eruption, enormous amounts of ash are thrown into the atmosphere. The ash encircles the globe. This blocks the Sun and lowers the temperature of the entire planet. The result is a volcanic winter. A supervolcano eruption took place at Lake Toba in northern Sumatra about 75,000 years ago (Figure 8.19). This was the largest eruption in the past 25 million years. As much as 2,800 cubic kilometers of material was ejected into the atmosphere. The result was a 6- to 10-year volcanic winter. Some scientists think that only 10,000 humans survived worldwide. The numbers of other mammals also plummeted. The most recent supervolcano eruption was in New Zealand. The eruption was less than 2000 years ago. For a supervolcano eruption it was small, about 100 cubic kilometers of material. A much larger super eruption in Colorado produced over 5,000 cubic kilometers of material. That eruption was 28 million years ago. It was 5000 times larger than the 1980 Mount St. Helens eruption. The largest potentially active supervolcano in North America is Yellowstone. The caldera has had three super eruptions at 2.1 million, 1.3 million and 640,000 years ago. The floor of the Yellowstone caldera is slowly rising upwards. Another eruption is very likely but no one knows when. The cause of supervolcano eruptions is being debated. Enormous magma chambers are filled with super hot magma. This enormous eruption leaves a huge hole. The ground collapses and creates a caldera. "
this famous geyser can be found at yellowstone national park.,(A) Old McDonald (B) Old Faithful (C) Old Woman (D) El Tatio,B,"Geysers are also created by water that is heated beneath the Earths surface. The water may become superheated by magma. It becomes trapped in a narrow passageway. The heat and pressure build as more water is added. When the pressure is too much, the superheated water bursts out onto the surface. This is a geyser. There are only a few areas in the world where the conditions are right for the formation of geysers. Only about 1,000 geysers exist worldwide. About half of them are in the United States. The most famous geyser is Old Faithful at Yellowstone National Park (Figure 8.23). It is rare for a geyser to erupt so regularly, which is why Old Faithful is famous. "
supervolcanoes can cause mass extinctions.,(A) True (B) False,A,"A supervolcano could change life on Earth as we know it. Ash could block sunlight so much that photosynthesis would be reduced and global temperatures would plummet. Volcanic eruptions could have contributed to some of the mass extinctions in our planets history. No one knows when the next super eruption will be. Interesting volcano videos are seen on National Geographic Videos, Environment Video, Natural Disasters, Earth- quakes: One interesting one is Mammoth Mountain, which explores Hot Creek and the volcanic area it is a part of in California. Click image to the left or use the URL below. URL: "
eruptions of hotspots beneath continents are extremely explosive because,(A) The eruptions occur frequently (B) The eruptions release enormous amounts of felsic lava (C) A massive plume massive enough to penetrate continental crust is very hot (D) Both a and c,C,"The hotspots that are known beneath continents are extremely large. The reason is that it takes a massive mantle plume to generate enough heat to penetrate through the relatively thick continental crust. The eruptions that come from these hotspots are infrequent but massive, often felsic and explosive. All thats left at Yellowstone at the moment is a giant caldera and a very hot spot beneath. "
"supervolcano eruptions happen somewhere on earth about every 1,000 years.",(A) True (B) False,B,"Supervolcano eruptions are extremely rare in Earths history. Its a good thing because they are unimaginably large. A supervolcano must erupt more than 1,000 cubic km (240 cubic miles) of material, compared with 1.2 km3 for Mount St. Helens or 25 km3 for Mount Pinatubo, a large eruption in the Philippines in 1991. Not surprisingly, supervolcanoes are the most dangerous type of volcano. "
a supervolcano can change life on earth by,(A) Blocking sunlight so that photosynthesis stops or slows (B) Raising temperature worldwide for years (C) Covering the entire surface of a continent with lava flows (D) All of these,A,"A supervolcano could change life on Earth as we know it. Ash could block sunlight so much that photosynthesis would be reduced and global temperatures would plummet. Volcanic eruptions could have contributed to some of the mass extinctions in our planets history. No one knows when the next super eruption will be. Interesting volcano videos are seen on National Geographic Videos, Environment Video, Natural Disasters, Earth- quakes: One interesting one is Mammoth Mountain, which explores Hot Creek and the volcanic area it is a part of in California. Click image to the left or use the URL below. URL: "
where do supervolcanoes usually form?,(A) Convergent boundary (B) Divergent boundary (C) Continental hotspots (D) All of these,C,"Some volcanoes form over active hot spots. Scientists count about 50 hot spots on the Earth. Hot spots may be in the middle of a tectonic plate. Hot spots lie directly above a column of hot rock called a mantle plume. Mantle plumes continuously bring magma up from the mantle towards the crust (Figure 8.3). As the tectonic plates move above a hot spot, they form a chain of volcanoes. The islands of Hawaii formed over a hot spot in the middle of the Pacific plate. The Hawaii hot spot has been active for tens of millions of years. The volcanoes of the Hawaiian Islands formed at this hot spot. Older volcanoes that formed at the hot spot have eroded below sea level. These are called the Emperor Seamounts. Loihi seamount is currently active beneath the water southeast of the Big Island of Hawaii. One day the volcano will rise above sea level and join the volcanoes of the island or create a new island (Figure 8.4). Hot spots may also be active at plate boundaries. This is especially common at mid-ocean ridges. Iceland is formed by a hot spot along the Mid-Atlantic Ridge. Hot spots are found within continents, but not as commonly as within oceans. The Yellowstone hot spot is a famous example of a continental hot spot. "
yellowstone is a supervolcano that has had three massive eruptions.,(A) True (B) False,A,"The largest supervolcano in North America is beneath Yellowstone National Park in Wyoming. Yellowstone sits above a hotspot that has erupted catastrophically three times: 2.1 million, 1.3 million, and 640,000 years ago. Yellowstone has produced many smaller (but still enormous) eruptions more recently (Figure 1.2). Fortunately, current activity at Yellowstone is limited to the regions famous geysers. Click image to the left or use the URL below. URL:  The Yellowstone hotspot has produced enormous felsic eruptions. The Yellowstone caldera collapsed in the most recent super eruption. "
sunspots are ____________.,(A) Warmer areas on the Sun (B) Cooler (C) darker areas of the Sun (D) c Landforms on the Sun (E) d Explosions on the Sun,B,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
which of the following is true about sunspots?,(A) They are where loops of the Sun’s magnetic field disrupt the transfer of heat (B) Because they are loops (C) they usually occur in pairs (D) c They have a minimum-maximum cycle that lasts 11 years (E) d All of these,D,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
violent explosions that release huge amounts of energy on the sun are called _____________.,(A) Sunspots (B) Solar winds (C) Solar flares (D) Solar spots,C,"A loop of the Suns magnetic field may break. This creates solar flares. Solar flares are violent explosions that release huge amounts of energy (Figure 24.19). The streams of high energy particles they emit make up the solar wind. Solar wind is dangerous to spacecraft and astronauts. Solar flares can even cause damage on Earth. They have knocked out entire power grids and can disturb radio, satellite, and cell phone communications. "
a coronal mass ejection,(A) Is the source of the solar wind (B) Can turn into a solar flare (C) Releases streams of slow moving particles (D) All of these,A,"There are other types of interruptions of the Suns magnetic energy. If a loop of the Suns magnetic field snaps and breaks, it creates solar flares, which are violent explosions that release huge amounts of energy (Figure 1.2). A strong solar flare can turn into a coronal mass ejection. A solar flare or coronal mass ejection releases streams of highly energetic particles that make up the solar wind. The solar wind can be dangerous to spacecraft and astronauts because it sends out large amounts of radiation that can harm the human body. Solar flares have knocked out entire power grids and disturbed radio, satellite, and cell phone communications. (a) Sunspots. (b) A close-up of a sunspot taken in ultraviolet light. "
sunspots occur in ___________.,(A) 1 year cycles (B) 5 year cycles (C) 11 year cycles (D) 20 year cycles,A,"The most noticeable surface features of the Sun are cooler, darker areas known as sunspots (Figure 1.1). Sunspots are located where loops of the Suns magnetic field break through the surface and disrupt the smooth transfer of heat from lower layers of the Sun, making them cooler, darker, and marked by intense magnetic activity. Sunspots usually occur in pairs. When a loop of the Suns magnetic field breaks through the surface, a sunspot is created where the loop comes out and where it goes back in again. Sunspots usually occur in 11-year cycles, increasing from a minimum number to a maximum number and then gradually decreasing to a minimum number again. "
solar prominences are _______________.,(A) Cooler (B) darker areas (C) b Interruptions of magnetic energy (D) c Plasma loops that connect two sunspots (E) d All of the above,C,"Another highly visible feature on the Sun are solar prominences. If plasma flows along a loop of the Suns magnetic field from sunspot to sunspot, it forms a glowing arch that reaches thousands of kilometers into the Suns atmosphere. Prominences can last lengths of time ranging from a day to several months. Prominences are also visible during a total solar eclipse. Most of the imagery comes from SDOs AIA instrument; different colors represent different temperatures, a common technique for observing solar features. SDO sees the entire disk of the Sun in extremely high spatial and temporal resolution, allowing scientists to zoom in on notable events such as flares, waves, and sunspots. "
prominences can last lengths of time ranging from days to months.,(A) True (B) False,A,"Another highly visible feature on the Sun are solar prominences. If plasma flows along a loop of the Suns magnetic field from sunspot to sunspot, it forms a glowing arch that reaches thousands of kilometers into the Suns atmosphere. Prominences can last lengths of time ranging from a day to several months. Prominences are also visible during a total solar eclipse. Most of the imagery comes from SDOs AIA instrument; different colors represent different temperatures, a common technique for observing solar features. SDO sees the entire disk of the Sun in extremely high spatial and temporal resolution, allowing scientists to zoom in on notable events such as flares, waves, and sunspots. "
nasas solar dynamics observatory is studying,(A) Nuclear fusion in the Sun (B) The effect of the Sun on Earth’s chemistry and climate (C) Changes of state between the four states of matter on the Sun (D) All of these,B,"The video above was taken from the SDO, the most advanced spacecraft ever designed to study the Sun. During its five-year mission, SDO will examine the Suns magnetic field and also provide a better understanding of the role the Sun plays in Earths atmospheric chemistry and climate. Since just after its launch on February 11, 2010, SDO is providing images with clarity 10 times better than high-definition television and will return more comprehensive science data faster than any other solar-observing spacecraft. The Solar Dynamics Observatory is a NASA spacecraft launched in early 2010 is obtaining IMAX-like images of the Sun every second of the day, generating more data than any NASA mission in history. The data will allow researchers to learn about solar storms and other phenomena that can cause blackouts and harm astronauts. Click image to the left or use the URL below. URL: "
earth is too far away to be affected by solar flares.,(A) True (B) False,B,"A loop of the Suns magnetic field may break. This creates solar flares. Solar flares are violent explosions that release huge amounts of energy (Figure 24.19). The streams of high energy particles they emit make up the solar wind. Solar wind is dangerous to spacecraft and astronauts. Solar flares can even cause damage on Earth. They have knocked out entire power grids and can disturb radio, satellite, and cell phone communications. "
spacecraft and astronauts can be harmed by radiation in space.,(A) True (B) False,A,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
"as women become educated,",(A) They have more babies (B) Their children are healthier (C) They no longer have time to care for their children (D) All of these,B,"Dr. Ochoa is one of just a few dozen female astronauts in the U.S. She is also the first Hispanic woman in the world to go into space. Although females make up more than half of the U.S. population, fewer than 25 percent of U.S. astronauts are women. Women are also under-represented in science, especially physical sciences such as chemistry and physics. What explains this? Throughout history, womenand also people of color of both gendershave rarely had the same chances as white males for education and careers in science. Cultural, social, and economic biases have made it far harder for them than for white males to excel in this area. This explains why there have been fewer scientists among their ranks. "
"for a more sustainable future, human population should be reduced.",(A) True (B) False,A,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
________________________ needs to be reduced to achieve a more sustainable future.,(A) Over-consumption (B) Population (C) Poverty (D) All of the above,D,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
which of these helps to make a more sustainable environment?,(A) Fish farming (B) done in an environmentally sound way (C) b Using more resources (D) c Replacing wood and metal with plastic products (E) d All of the above,A,"Can society change and get on a sustain- able path? A topic generating a great deal of discussion these days is sustainable development. The goals of sustainable development are to: help people out of poverty. protect the environment. use resources no faster than the rate at which they are regenerated. Science can be an important part of sustainable development. When scientists understand how Earths natural systems work, they can recognize how people are impacting them. Scientists can work to develop technologies that can be used to solve problems wisely. An example of a practice that can aid sustainable development is fish farming, as long as it is done in environmentally sound ways. Engineers can develop cleaner energy sources to reduce pollution and greenhouse gas emissions. Citizens can change their behavior to reduce the impact they have on the planet by demanding products that are produced sustainably. When forests are logged, new trees should be planted. Mining should be done so that the landscape is not destroyed. People can consume less and think more about the impacts of what they do consume. And what of the waste products of society? Will producing all that we need to keep the population growing result in a planet so polluted that the quality of life will be greatly diminished? Will warming temperatures cause problems for human populations? The only answer to all of these questions is, time will tell. Click image to the left or use the URL below. URL: "
"to be sustainable, we need to",(A) Stop using resources (B) Take the resources we have in whatever way possible while we develop new resources (C) Reduce the impact obtaining and using resources has on the planet (D) All of the above,C,"Can society change and get on a sustain- able path? A topic generating a great deal of discussion these days is sustainable development. The goals of sustainable development are to: help people out of poverty. protect the environment. use resources no faster than the rate at which they are regenerated. Science can be an important part of sustainable development. When scientists understand how Earths natural systems work, they can recognize how people are impacting them. Scientists can work to develop technologies that can be used to solve problems wisely. An example of a practice that can aid sustainable development is fish farming, as long as it is done in environmentally sound ways. Engineers can develop cleaner energy sources to reduce pollution and greenhouse gas emissions. Citizens can change their behavior to reduce the impact they have on the planet by demanding products that are produced sustainably. When forests are logged, new trees should be planted. Mining should be done so that the landscape is not destroyed. People can consume less and think more about the impacts of what they do consume. And what of the waste products of society? Will producing all that we need to keep the population growing result in a planet so polluted that the quality of life will be greatly diminished? Will warming temperatures cause problems for human populations? The only answer to all of these questions is, time will tell. Click image to the left or use the URL below. URL: "
"in order to create a more sustainable environment, we need to use resources faster than they are regenerated.",(A) True (B) False,B,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
sustainable development is only concerned with protecting the environment.,(A) True (B) False,B,Soil is only a renewable resource if it is carefully managed. There are many practices that can protect and preserve soil resources. 
when forests are logged,(A) The hillside should be abandoned (B) Fire should be set to clean up debris (C) New trees should be planted (D) All of these,C,"Logging removes trees that protect the ground from soil erosion. The tree roots hold the soil together and the tree canopy protects the soil from hard falling rain. Logging results in the loss of leaf litter, or dead leaves, bark, and branches on the forest floor. Leaf litter plays an important role in protecting forest soils from erosion (Figure 1.3). Logging exposes large areas of land to erosion. Much of the worlds original forests have been logged. Many of the tropical forests that remain are currently the site of logging because North America and Europe have already harvested many of their trees (Figure 1.4). Soils eroded from logged forests clog rivers and lakes, fill estuaries, and bury coral reefs. Surface mining disturbs the land (Figure 1.5) and leaves the soil vulnerable to erosion. "
what is the role of science in sustainable development?,(A) Understanding how humans are impacting Earth’s natural systems (B) Developing technologies to solve the problem of air pollution (C) Understanding and designing ways to reduce global warming (D) All of these,D,"Can society change and get on a sustain- able path? A topic generating a great deal of discussion these days is sustainable development. The goals of sustainable development are to: help people out of poverty. protect the environment. use resources no faster than the rate at which they are regenerated. Science can be an important part of sustainable development. When scientists understand how Earths natural systems work, they can recognize how people are impacting them. Scientists can work to develop technologies that can be used to solve problems wisely. An example of a practice that can aid sustainable development is fish farming, as long as it is done in environmentally sound ways. Engineers can develop cleaner energy sources to reduce pollution and greenhouse gas emissions. Citizens can change their behavior to reduce the impact they have on the planet by demanding products that are produced sustainably. When forests are logged, new trees should be planted. Mining should be done so that the landscape is not destroyed. People can consume less and think more about the impacts of what they do consume. And what of the waste products of society? Will producing all that we need to keep the population growing result in a planet so polluted that the quality of life will be greatly diminished? Will warming temperatures cause problems for human populations? The only answer to all of these questions is, time will tell. Click image to the left or use the URL below. URL: "
to help society become more sustainable every individual should consume less and think about the impacts of what they consume.,(A) True (B) False,A,"Can society change and get on a sustain- able path? A topic generating a great deal of discussion these days is sustainable development. The goals of sustainable development are to: help people out of poverty. protect the environment. use resources no faster than the rate at which they are regenerated. Science can be an important part of sustainable development. When scientists understand how Earths natural systems work, they can recognize how people are impacting them. Scientists can work to develop technologies that can be used to solve problems wisely. An example of a practice that can aid sustainable development is fish farming, as long as it is done in environmentally sound ways. Engineers can develop cleaner energy sources to reduce pollution and greenhouse gas emissions. Citizens can change their behavior to reduce the impact they have on the planet by demanding products that are produced sustainably. When forests are logged, new trees should be planted. Mining should be done so that the landscape is not destroyed. People can consume less and think more about the impacts of what they do consume. And what of the waste products of society? Will producing all that we need to keep the population growing result in a planet so polluted that the quality of life will be greatly diminished? Will warming temperatures cause problems for human populations? The only answer to all of these questions is, time will tell. Click image to the left or use the URL below. URL: "
"to test a hypothesis, a scientist could",(A) Look to the scientific literature (B) Perform experiments (C) Make observations (D) All of the above,D,"To test the hypothesis, an experiment will be done. You would count the healthy and deformed frogs and measure the amount of chemical X in all of the ponds. The hypothesis will be either true or false. Doing an experiment will test most hypotheses. The experiment may generate evidence in support of the hypothesis. The experiment may also generate evidence proving the hypothesis false. Once you collect your data, it will need to be analyzed. "
why does a hypothesis have to be falsifiable?,(A) It must be able to pass all its tests (B) Only if it is falsified can it be right (C) It must be possible to show that it is wrong (D) All of the above,C,"For a hypothesis to be testable means that it is possible to make observations that agree or disagree with it. If a hypothesis cannot be tested by making observations, it is not scientific. Consider this statement: ""There are invisible creatures all around us that we can never observe in any way."" This statement may or may not be true, but it is not a scientific hypothesis. Thats because it cant be tested. Given the nature of the hypothesis, there are no observations a scientist could make to test whether or not it is false. "
the hypothesis - the increase in carbon dioxide in the atmosphere is due to increased volcanic activity - is wrong because,(A) Volcanic gas compositions and eruption rates have not changed over time (B) There has been an increase in volcanic eruptions in recent decades (C) The carbon dioxide in volcanic gases has increased over time (D) Volcanic gas compositions have changed (E) but eruption rates have not changed over time,D,"Atmospheric CO2 has increased over the past five decades, because the amount of CO2 gas released by volcanoes has increased. "
"when a hypothesis is being tested the scientific method is not followed, the hypothesis must be",(A) Accepted (B) Discarded immediately (C) Turned into a theory (D) Tested again,D,"For a hypothesis to be testable means that it is possible to make observations that agree or disagree with it. If a hypothesis cannot be tested by making observations, it is not scientific. Consider this statement: ""There are invisible creatures all around us that we can never observe in any way."" This statement may or may not be true, but it is not a scientific hypothesis. Thats because it cant be tested. Given the nature of the hypothesis, there are no observations a scientist could make to test whether or not it is false. "
one of the reasons for the increase in carbon dioxide in the atmosphere is due to the increase in the amount of fossil fuels used.,(A) True (B) False,A,"Hypothesis 2 states that the increase in atmospheric CO2 is due to the increase in the amount of fossil fuels that are being burned. We look into the scientific literature and find this graph in the Figure 1.1. Global carbon dioxide emissions from fos- sil fuel consumption and cement produc- tion. The black line represents all emis- sion types combined, and colored lines show emissions from individual fossil fu- els. Fossil fuels have added an increasing amount of carbon dioxide to the atmosphere since the beginning of the Industrial Revolution in the mid 19th century. Hypothesis 2 is true! Click image to the left or use the URL below. URL: "
a series of steps that help to investigate a scientific question is,(A) A hypothesis (B) Data (C) The scientific method (D) A theory,C,"Scientists use the scientific method to answer questions. The scientific method is a series of steps that help to investigate a question. Often, students learn that the scientific method is a linear process that goes like this: Ask a question. The question is based on one or more observations or on data from a previous experiment. Do some background research. Create a hypothesis. Do experiments or make observations to test the hypothesis. Gather the data. Formulate a conclusion. The process doesnt always go in a straight line. A scientist might ask a question, then do some background research and discover that the question needed to be asked a different way, or that a different question should be asked. Click image to the left or use the URL below. URL: "
"data are facts that have been uncovered from the scientific literature, or by systematic observations or experiments.",(A) True (B) False,A,"Scientists usually begin an investigation with facts. A fact is a bit of information that is true. Facts come from data collected from observations or from experiments that have already been run. Data is factual information that is not subject to opinion or bias. What is a fact? Look at the following list and identify if the statement is a fact (from observation or prior experi- ments), an opinion, or a combination. Can you be sure from the photo that Susan has a cold? 1. 2. 3. 4. 5. 6. 7. Susan has long hair. Susan is sneezing and has itchy eyes. She is not well. She has a cold. Colds are caused by viruses. Echinacea is an herb that prevents colds. Bill Gates is the smartest man in the United States. People born under the astrological sign Leo are fiery, self-assured, and charming. Average global temperature has been rising at least since 1960. "
which of these can help scientists to test a hypothesis?,(A) Observations (B) Analysis (C) Conclusions (D) All of the above,D,If we were doing a scientific investigation we need to gather the information to test the hypotheses ourselves. We would do this by making observations or running experiments. 
having multiple working hypotheses helps in investigating a question.,(A) True (B) False,A,"After doing the research, the farmer will try to answer the question. She might think, If I dont plow my fields, I will lose less soil than if I do plow the fields. Plowing disrupts the soil and breaks up roots that help hold soil in place. This answer to her question is a hypothesis. A hypothesis is a reasonable explanation. A hypothesis can be tested. It may be the right answer, it may be a wrong answer, but it must be testable. Once she has a hypothesis, the next step is to do experiments to test the hypothesis. A hypothesis can be proved or disproved by testing. If a hypothesis is repeatedly tested and shown to be true, then scientists call it a theory. "
which type of data has been used to identify the phenomenon of increasing carbon dioxide levels in the atmosphere?,(A) Experiments (B) Measurements (C) Visual observations (D) None of these,B,"Before we develop some hypotheses, lets find a new question that we want to answer. What we just learned that atmospheric CO2 has been increasing at least since 1958. This leads us to ask this question: Why is atmospheric CO2 increasing? "
perhaps the most important feature of the outermost layers of the atmosphere is the low density of the gas particles.,(A) True (B) False,A,"The density of molecules is so low in the thermosphere that one gas molecule can go about 1 km before it collides with another molecule. Since so little energy is transferred, the air feels very cold (See opening image). "
this layer bounces off radio waves back to earth.,(A) Magnetosphere (B) Ionosphere (C) Mesosphere (D) Stratosphere,B,"About half of the solar radiation that strikes the top of the atmosphere is filtered out before it reaches the ground. This energy can be absorbed by atmospheric gases, reflected by clouds, or scattered. Scattering occurs when a light wave strikes a particle and bounces off in some other direction. About 3% of the energy that strikes the ground is reflected back into the atmosphere. The rest is absorbed by rocks, soil, and water and then radiated back into the air as heat. These infrared wavelengths can only be seen by infrared sensors. Click image to the left or use the URL below. URL: "
the aurora borealis is found in this layer.,(A) Magnetosphere (B) Ionosphere (C) Mesosphere (D) Stratosphere,A,"When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the most spectacular feature of the ionosphere  the nighttime aurora (Figure 1.1). The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, causing them to light up. Each gas emits a particular color of light. (a) Spectacular light displays are visible as the aurora borealis or northern lights in the Northern Hemisphere. (b) The aurora australis or southern lights encircles Antarctica. What would Earths magnetic field look like if it were painted in colors? It would look like the aurora! This QUEST video looks at the aurora, which provides clues about the solar wind, Earths magnetic field and Earths atmosphere. Click image to the left or use the URL below. URL: "
which gas molecules get energized to make the auroras?,(A) Oxygen (B) Nitrogen (C) Hydrogen (D) A & B,D,"When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the most spectacular feature of the ionosphere  the nighttime aurora (Figure 1.1). The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, causing them to light up. Each gas emits a particular color of light. (a) Spectacular light displays are visible as the aurora borealis or northern lights in the Northern Hemisphere. (b) The aurora australis or southern lights encircles Antarctica. What would Earths magnetic field look like if it were painted in colors? It would look like the aurora! This QUEST video looks at the aurora, which provides clues about the solar wind, Earths magnetic field and Earths atmosphere. Click image to the left or use the URL below. URL: "
"at the edge of the outermost layer of the atmosphere, the __________, the atmosphere __________.",(A) Ionosphere; merges with outer space (B) Ionosphere; ends abruptly (C) Exosphere; merges with outer space (D) Exosphere; ends abruptly,C,"There is no real outer limit to the exosphere, the outermost layer of the atmosphere; the gas molecules finally become so scarce that at some point there are no more. Beyond the atmosphere is the solar wind. The solar wind is made of high-speed particles, mostly protons and electrons, traveling rapidly outward from the Sun. "
the solar wind is,(A) Energized oxygen and nitrogen gas molecules that travel outward from the sun (B) High speed particles traveling rapidly outward from the sun (C) The magnetic field of the sun that intersects the orbits of the inner planets (D) The movement of solar gases from high pressure areas to low pressure areas,B,"The sun gives off radiation in solar winds. You can see solar winds in the Figure 1.1. Notice what happens to solar winds when they reach the magnetosphere. They are deflected almost completely by Earths magnetic field. Radiation in solar wind would wash over Earth and kill most living things were it not for the magnetosphere. It protects Earths organisms from radiation like an umbrella protects you from rain. Q: Now can you explain the northern lights? A: Energetic particles in solar wind collide with atoms in the atmosphere over the poles, and energy is released in the form of light. The swirling patterns of light follow lines of magnetic force in the magnetosphere. "
the aurora occur during massive solar storms when the van allen belts are overloaded with particles.,(A) True (B) False,A,"When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the most spectacular feature of the ionosphere  the nighttime aurora (Figure 1.1). The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, causing them to light up. Each gas emits a particular color of light. (a) Spectacular light displays are visible as the aurora borealis or northern lights in the Northern Hemisphere. (b) The aurora australis or southern lights encircles Antarctica. What would Earths magnetic field look like if it were painted in colors? It would look like the aurora! This QUEST video looks at the aurora, which provides clues about the solar wind, Earths magnetic field and Earths atmosphere. Click image to the left or use the URL below. URL: "
how does the ionosphere get its name?,(A) Solar radiation ionizes gas molecules into positive and negative charges (B) The magnetic field breaks apart nitrogen and oxygen gas into ions in the atmosphere (C) Solar storms cause the particles in the Van Allen belts to ionize (D) Ultraviolet radiation breaks apart atmospheric gases into positive and negative charges,A,"Within the thermosphere is the ionosphere. The ionosphere gets its name from the solar radiation that ionizes gas molecules to create a positively charged ion and one or more negatively charged electrons. The freed electrons travel within the ionosphere as electric currents. Because of the free ions, the ionosphere has many interesting characteristics. At night, radio waves bounce off the ionosphere and back to Earth. This is why you can often pick up an AM radio station far from its source at night. "
where is the aurora australis found?,(A) In the Northern Hemisphere (B) near the North Pole (C) b Encircling the Equator (D) c Around the Tropics of Cancer and Capricorn (E) d In the Southern Hemisphere (F) near the South Pole,D,"Have you ever seen a brilliant light show in the night sky? Sometimes the ions in the thermosphere glow at night. Storms on the Sun energize the ions and make them light up. In the Northern Hemisphere, the lights are called the northern lights, or aurora borealis. In the Southern Hemisphere, they are called southern lights, or aurora australis. "
what are the van allen belts?,(A) A belt-like structure around the Tropics of Cancer and Capricorn where the solar wind strikes (B) Two doughnut-shaped zones of highly charged particles located high in the atmosphere (C) The polar location where the aurora get their start (D) Where ions travel as electric currents in the magnetosphere,C,"The Van Allen radiation belts are two doughnut-shaped zones of highly charged particles that are located very high the atmosphere in the magnetosphere. The particles originate in solar flares and fly to Earth on the solar wind. Once trapped by Earths magnetic field, they follow along the fields magnetic lines of force. These lines extend from above the Equator to the North Pole and also to the South Pole, then return to the Equator. "
tides are most affected by the,(A) Gravitational pull of the Sun (B) Gravitational pull of the Moon (C) Gravitational pull of Jupiter (D) Gravitational pull of Venus,B,"The Suns gravity also pulls on Earth and its oceans. Even though the Sun is much larger than the Moon, the pull of the Suns gravity is much less because the Sun is much farther away. The Suns gravity strengthens or weakens the Moons influence on tides. Figure 14.14 shows the position of the Moon relative to the Sun at different times during the month. The positions of the Moon and Sun relative to each other determines how the Sun affects tides. This creates spring tides or neap tides. Spring tides occur during the new moon and full moon. The Sun and Moon are in a straight line either on the same side of Earth or on opposite sides. Their gravitational pull combines to cause very high and very low tides. Spring tides have the greatest tidal range. Neap tides occur during the first and third quarters of the Moon. The Moon and Sun are at right angles to each other. Their gravity pulls on the oceans in different directions so the highs and lows are not as great. Neap tides have the smallest tidal range. This animation shows the effect of the Moon and Sun on the tides: "
"when two water bulges on opposite sides of the earth aligned with the moon, they are called low tides.",(A) True (B) False,B,"Figure 14.13 shows why tides occur. The main cause of tides is the pull of the Moons gravity on Earth. The pull is greatest on whatever is closest to the Moon. Although the gravity pulls the land, only the water can move. As a result: Water on the side of Earth facing the Moon is pulled hardest by the Moons gravity. This causes a bulge of water on that side of Earth. That bulge is a high tide. Earth itself is pulled harder by the Moons gravity than is the ocean on the side of Earth opposite the Moon. As a result, there is bulge of water on the opposite side of Earth. This creates another high tide. With water bulging on two sides of Earth, theres less water left in between. This creates low tides on the other two sides of the planet. "
a low tide occurs beneath the point where,(A) Sun and Moon are on the same side of Earth (B) Sun and Moon are at opposite sides of Earth (C) Sun and Moon are at 90-degrees to each other (D) relative to Earth (E) d None of these,C,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
"if you wanted to go tide pooling on the shore and see the most tide pools, you should go",(A) During a neap tide (B) when the tide is high (C) b During a spring tide (D) when the tide is high (E) c During a neap tide (F) when the tide is low (G) d During a spring tide (H) when the tide is low,D,"Shores are attractive places to live and vacation. But development at the shore is at risk of damage from waves. Wave erosion threatens many homes and beaches on the ocean. This is especially true during storms, when waves may be much larger than normal. "
"if a high tide takes place at happiness beach at midnight on day 1, when will it be low tide?",(A) 6:125 am on Day 1 (B) 12:25 pm on Day 1 (C) 6:375 pm on Day 1 (D) 12:50 am on Day 2,A,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
these tides have the smallest tidal range.,(A) Spring tides (B) Neap tides (C) High tides (D) Low tides,B,"The tidal range is the difference between the ocean level at high tide and the ocean level at low tide (Figure 1.2). The tidal range in a location depends on a number of factors, including the slope of the seafloor. Water appears to move a greater distance on a gentle slope than on a steep slope. "
neap tides have a low tidal range because,(A) Moon’s high tide occurs in the same place as the Sun’s low tide (B) Moon’s low tide occurs in the same place as the Sun’s high tide (C) Moon’s high tide occurs opposite of the Sun’s low tide (D) Both A & B,D,"If you look at the diagram of high and low tides on a circular Earth above, youll see that tides are waves. So when the Sun and Moon are aligned, what do you expect the tides to look like? Waves are additive, so when the gravitational pull of both bodies is in the same direction, the high tides are higher and the low tides lower than at other times through the month (Figure 1.3). These more extreme tides, with a greater tidal range, are called spring tides. Spring tides dont just occur in the spring; they occur whenever the Moon is in a new-moon or full-moon phase, about every 14 days. Neap tides are tides that have the smallest tidal range, and they occur when the Earth, the Moon, and the Sun form a 90o angle (Figure 1.4). They occur exactly halfway between the spring tides, when the Moon is at first or last quarter. How do the tides add up to create neap tides? The Moons high tide occurs in the same place as the Suns low tide and the Moons low tide in the same place as the Suns high tide. At neap tides, the tidal range is relatively small. The tidal range is the difference between the ocean level at high tide and low tide. Studying ocean tides rhythmic movements helps scientists understand the ocean and the Sun/Moon/Earth system. This QUEST video explains how tides work, and visits the oldest continually operating tidal gauge in the Western Hemisphere. Click image to the left or use the URL below. URL: "
there is only one high and one low tide a day.,(A) True (B) False,B,"Tides are daily changes in the level of ocean water. They occur all around the globe. High tides occur when the water reaches its highest level in a day. Low tides occur when the water reaches its lowest level in a day. Tides keep cycling from high to low and back again. In most places the water level rises and falls twice a day. So there are two high tides and two low tides approximately every 24 hours. In Figure 14.12, you can see the difference between high and low tides. This is called the tidal range. "
"tides, like other waves, are additive.",(A) True (B) False,A,"If you look at the diagram of high and low tides on a circular Earth above, youll see that tides are waves. So when the Sun and Moon are aligned, what do you expect the tides to look like? Waves are additive, so when the gravitational pull of both bodies is in the same direction, the high tides are higher and the low tides lower than at other times through the month (Figure 1.3). These more extreme tides, with a greater tidal range, are called spring tides. Spring tides dont just occur in the spring; they occur whenever the Moon is in a new-moon or full-moon phase, about every 14 days. Neap tides are tides that have the smallest tidal range, and they occur when the Earth, the Moon, and the Sun form a 90o angle (Figure 1.4). They occur exactly halfway between the spring tides, when the Moon is at first or last quarter. How do the tides add up to create neap tides? The Moons high tide occurs in the same place as the Suns low tide and the Moons low tide in the same place as the Suns high tide. At neap tides, the tidal range is relatively small. The tidal range is the difference between the ocean level at high tide and low tide. Studying ocean tides rhythmic movements helps scientists understand the ocean and the Sun/Moon/Earth system. This QUEST video explains how tides work, and visits the oldest continually operating tidal gauge in the Western Hemisphere. Click image to the left or use the URL below. URL: "
"tree trunks alternating bands of light-colored, high density summer growth and low-density winter growth.",(A) True (B) False,B,"In locations where summers are warm and winters are cool, trees have a distinctive growth pattern. Tree trunks display alternating bands of light-colored, low density summer growth and dark, high density winter growth. Each light-dark band represents one year. By counting tree rings it is possible to find the number of years the tree lived (Figure 1.1). The width of these growth rings varies with the conditions present that year. A summer drought may make the tree grow more slowly than normal and so its light band will be relatively small. These tree-ring variations appear in all trees in a region. The same distinctive pattern can be found in all the trees in an area for the same time period. Scientists have created continuous records of tree rings going back over the past 2,000 years. Wood fragments from old buildings and ancient ruins can be age dated by matching up the pattern of tree rings in the wood fragment in Cross-section showing growth rings. question and the scale created by scientists. The outermost ring indicates when the tree stopped growing; that is, when it died. The tree-ring record is extremely useful for finding the age of ancient structures. "
if there is a summer drought __________________________.,(A) The tree will grow faster and light bands will be small (B) The tree will grow slower and the light bands will be small (C) The tree will not grow and the bands will not change (D) None of the above,B,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
which of these statements is true?,(A) The outmost ring in a tree cross-section indicates when the tree stopped growing (B) The tree-ring record is useful for finding the age of ancient structures (C) Distinctive patterns can be found in all trees in an area for the same time period (D) All of the above are true,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
"ice cores show that snow falls in winter but in summer, dust accumulates.",(A) True (B) False,A,"Besides tree rings, other processes create distinct yearly layers that can be used for dating. On a glacier, snow falls in winter but in summer dust accumulates. This leads to a snow-dust annual pattern that goes down into the ice (Figure gather allows them to determine how the environment has changed as the glacier has stayed in its position. Analyses of the ice tell how concentrations of atmospheric gases changed, which can yield clues about climate. The longest cores allow scientists to create a record of polar climate stretching back hundreds of thousands of years. "
what is true about ice cores?,(A) Ice cores can determine how the environment has changed (B) Ice cores can tell how concentrations of atmospheric gases have changed (C) Ice cores can help scientists create a record of the local climate for thousands of years (D) All of the above are true,D,"Besides tree rings, other processes create distinct yearly layers that can be used for dating. On a glacier, snow falls in winter but in summer dust accumulates. This leads to a snow-dust annual pattern that goes down into the ice (Figure gather allows them to determine how the environment has changed as the glacier has stayed in its position. Analyses of the ice tell how concentrations of atmospheric gases changed, which can yield clues about climate. The longest cores allow scientists to create a record of polar climate stretching back hundreds of thousands of years. "
"in a varve, summer is represented by",(A) Sediment from melting glaciers (B) Clay from wind-blown dust (C) Ash from nearby volcanoes (D) None of these,A,"Lake sediments, especially in lakes that are located at the end of glaciers, also have an annual pattern. In the summer, the glacier melts rapidly, producing a thick deposit of sediment. These alternate with thin, clay-rich layers deposited in the winter. The resulting layers, called varves, give scientists clues about past climate conditions (Figure 1.3). A warm summer might result in a very thick sediment layer while a cooler summer might yield a thinner layer. "
a cold year is indicated in a varve by a thick deposit of sediment.,(A) True (B) False,B,"Lake sediments, especially in lakes that are located at the end of glaciers, also have an annual pattern. In the summer, the glacier melts rapidly, producing a thick deposit of sediment. These alternate with thin, clay-rich layers deposited in the winter. The resulting layers, called varves, give scientists clues about past climate conditions (Figure 1.3). A warm summer might result in a very thick sediment layer while a cooler summer might yield a thinner layer. "
varves form in __________ .,(A) The deep ocean (B) Coastal regions (C) Lakes (D) Shallow ponds,C,"Several types of stratified deposits form in glacial regions but are not formed directly by the ice. Varves form where lakes are covered by ice in the winter. Dark, fine-grained clays sink to the bottom in winter, but melting ice in spring brings running water that deposits lighter colored sands. Each alternating dark/light layer represents one year of deposits. (a) An esker is a winding ridge of sand and gravel deposited under a glacier by a stream of meltwater. (b) A drumlin is an asymmetrical hill made of sediments that points in the direction the ice moved. Usually drumlins are found in groups called drumlin fields. Click image to the left or use the URL below. URL: "
a piece of wood from an archeological site can be dated by tree rings if,(A) It is no more than around 200 years old (B) It has a pattern that matches the scale created by scientists (C) It was not taken from a tree that was cut a long distance from the site (D) All of these,B,"In locations where summers are warm and winters are cool, trees have a distinctive growth pattern. Tree trunks display alternating bands of light-colored, low density summer growth and dark, high density winter growth. Each light-dark band represents one year. By counting tree rings it is possible to find the number of years the tree lived (Figure 1.1). The width of these growth rings varies with the conditions present that year. A summer drought may make the tree grow more slowly than normal and so its light band will be relatively small. These tree-ring variations appear in all trees in a region. The same distinctive pattern can be found in all the trees in an area for the same time period. Scientists have created continuous records of tree rings going back over the past 2,000 years. Wood fragments from old buildings and ancient ruins can be age dated by matching up the pattern of tree rings in the wood fragment in Cross-section showing growth rings. question and the scale created by scientists. The outermost ring indicates when the tree stopped growing; that is, when it died. The tree-ring record is extremely useful for finding the age of ancient structures. "
an ice core can reveal the climate in the region for hundreds of thousands of years.,(A) True (B) False,A,"Besides tree rings, other processes create distinct yearly layers that can be used for dating. On a glacier, snow falls in winter but in summer dust accumulates. This leads to a snow-dust annual pattern that goes down into the ice (Figure gather allows them to determine how the environment has changed as the glacier has stayed in its position. Analyses of the ice tell how concentrations of atmospheric gases changed, which can yield clues about climate. The longest cores allow scientists to create a record of polar climate stretching back hundreds of thousands of years. "
clouds are in this layer of the atmosphere.,(A) Mesosphere (B) Troposphere (C) Stratosphere (D) Thermosphere,B,Clouds form when air in the atmosphere reaches the dew point. Clouds may form anywhere in the troposphere. Clouds that form on the ground are called fog. 
"if a mountaintop is 10,000 feet higher than the valley below, we can expect the temperature to be about",(A) Lower by about 36oF (B) Higher by about 36oF (C) The same (D) Different (E) but it is not possible to estimate the difference,A,"Air temperature falls at higher altitudes. You can see this in Figure 17.6. Why does this happen? Since air is less dense at higher altitudes, its molecules are spread farther apart than they are at sea level. These molecules have fewer collisions, so they produce less heat. Look at the mountain in Figure 17.7. The peak of Mount Kilimanjaro, Tanzania (Africa, 3 south latitude) is 6 kilometers (4 miles) above sea level. At 3 S its very close to the equator. At the bottom of the mountain, the temperature is high year round. How can you tell that its much cooler at the top? "
in an inversion,(A) Stratospheric air sits over tropospheric air (B) Tropospheric air sits over stratospheric air (C) Warm air sits over cold air (D) Cold air sits over warm air,C,"Sometimes air doesnt mix in the troposphere. This happens when air is cooler close to the ground than it is above. The cool air is dense, so it stays near the ground. This is called a temperature inversion. An inversion can trap air pollution near the surface. Temperature inversions are more common in the winter. Can you explain why? "
inversions are very stable and may last for several days or even weeks.,(A) True (B) False,A,"Sometimes there is a temperature inversion, in which air temperature in the troposphere increases with altitude and warm air sits over cold air. Inversions are very stable and may last for several days or even weeks. Inversions form: Over land at night or in winter when the ground is cold. The cold ground cools the air that sits above it, making this low layer of air denser than the air above it. Near the coast, where cold seawater cools the air above it. When that denser air moves inland, it slides beneath the warmer air over the land. Since temperature inversions are stable, they often trap pollutants and produce unhealthy air conditions in cities (Figure 1.1). Smoke makes a temperature inversion visible. The smoke is trapped in cold dense air that lies beneath a cap of warmer air. At the top of the troposphere is a thin layer in which the temperature does not change with height. This means that the cooler, denser air of the troposphere is trapped beneath the warmer, less dense air of the stratosphere. Air from the troposphere and stratosphere rarely mix. Click image to the left or use the URL below. URL: "
air from the troposphere and stratosphere commonly mix.,(A) True (B) False,B,"There is little mixing between the stratosphere, the layer above the troposphere, and the troposphere below it. The two layers are quite separate. Sometimes ash and gas from a large volcanic eruption may burst into the stratosphere. Once in the stratosphere, it remains suspended there for many years because there is so little mixing between the two layers. "
"in large western cities in winter, like phoenix or salt lake city, inversions are visible because",(A) They trap carbon monoxide (B) They trap smoke from wood fires (C) They trap ozone (D) All of the above,B,"Sometimes there is a temperature inversion, in which air temperature in the troposphere increases with altitude and warm air sits over cold air. Inversions are very stable and may last for several days or even weeks. Inversions form: Over land at night or in winter when the ground is cold. The cold ground cools the air that sits above it, making this low layer of air denser than the air above it. Near the coast, where cold seawater cools the air above it. When that denser air moves inland, it slides beneath the warmer air over the land. Since temperature inversions are stable, they often trap pollutants and produce unhealthy air conditions in cities (Figure 1.1). Smoke makes a temperature inversion visible. The smoke is trapped in cold dense air that lies beneath a cap of warmer air. At the top of the troposphere is a thin layer in which the temperature does not change with height. This means that the cooler, denser air of the troposphere is trapped beneath the warmer, less dense air of the stratosphere. Air from the troposphere and stratosphere rarely mix. Click image to the left or use the URL below. URL: "
what is the heat source for the troposphere?,(A) Earth’s surface (B) Earth’s core (C) The sun (D) Both a and c,A,"In the stratosphere, temperature increases with altitude. What is the heat source for the stratosphere? The direct heat source for the stratosphere is the Sun. The ozone layer in the stratosphere absorbs high energy ultraviolet radiation, which breaks the ozone molecule (3-oxygens) apart into an oxygen molecule (2-oxygens) and an oxygen atom (1- oxygen). In the mid-stratosphere there is less UV light and so the oxygen atom and molecule recombine to from ozone. The creation of the ozone molecule releases heat. Because warmer, less dense air sits over cooler, denser air, air in the stratosphere is stable. As a result, there is little mixing of air within the layer. There is also little interaction between the troposphere and stratosphere for this reason. "
the temperature decreases with altitude in the troposphere because,(A) Heat radiates from Earth’s surface (B) The density of atmospheric gases is higher (C) Sunlight radiates toward the surface (D) A & B,D,"The troposphere is the lowest layer of the atmosphere. In it, temperature decreases with altitude. The troposphere gets some of its heat directly from the Sun. Most, however, comes from Earths surface. The surface is heated by the Sun and some of that heat radiates back into the air. This makes the temperature higher near the surface than at higher altitudes. "
air in the troposphere does a lot of mixing because,(A) Solar energy is stronger at the top of the troposphere than at the bottom (B) Cooler air is beneath warmer air (C) which is unstable (D) c Warmer air is beneath cooler air (E) which is unstable (F) d A & B,C,"Air in the troposphere is warmer closer to Earths surface. Warm air is less dense than cool air, so it rises higher in the troposphere. This starts a convection cell. Convection mixes the air in the troposphere. Rising air is also a main cause of weather. All of Earths weather takes place in the troposphere. "
an inversion at night in a valley when,(A) Warm ground warms the air above it so that it rises and gets above the cold air above it (B) Cold ground cools the air above it (C) Cold ground cools the air above it so that it is dense and does not mix with the warmer (D) All of the above,C,"Temperature differences between mountains and valleys create mountain and valley breezes. During the day, air on mountain slopes is heated more than air at the same elevation over an adjacent valley. As the day progresses, warm air rises and draws the cool air up from the valley, creating a valley breeze. At night the mountain slopes cool more quickly than the nearby valley, which causes a mountain breeze to flow downhill. "
tsunami is japanese for,(A) Tidal Wave (B) Large Wave (C) Harbor Wave (D) Great Wave,C,"The Japanese received a one-two punch in March 2011. The 2011 Tohoku earthquake offshore was a magnitude 9.0 and damage from the quake was extensive. People didnt have time to recover before massive tsunami waves hit the island nation. As seen in Figure 1.2, waves in some regions topped 9 meters (27 feet). The tsunami did much more damage than the massive earthquake (Figure 1.3). Worst was the damage done to nuclear power plants along the northeastern coast. Eleven reactors were automatically shut down. Power and backup power were lost at the Fukushima plant, leading to equipment failures, meltdowns, and the release of radioactive materials. Control and cleanup of the disabled plants will go on for many years. "
the 2004 indian ocean tsunami killed so many people because,(A) It struck all around the Indian Ocean so many settlements were hit (B) It was an enormous wave (C) generated by an enormous earthquake (D) c The people of the region did not expect a tsunami so there was no warning system (E) d All of the above,D,"Not everyone had the same warning the people on Tillys beach had. The Boxing Day Tsunami of December 26, 2004 was by far the deadliest of all time (Figure 1.1). The tsunami was caused by the 2004 Indian Ocean Earthquake. With a magnitude of 9.2, it was the second largest earthquake ever recorded. The extreme movement of the crust displaced trillions of tons of water along the entire length of the rupture. Several tsunami waves were created with about 30 minutes between the peaks of each one. The waves that struck nearby Sumatra 15 minutes after the quake reached more than 10 meters (33 feet) in height. The size of the waves decreased with distance from the earthquake and were about 4 meters (13 feet) high in Somalia. The tsunami did so much damage because it traveled throughout the Indian Ocean. About 230,000 people died in eight countries. There were fatalities even as far away as South Africa, nearly 8,000 kilometers (5,000 miles) from the earthquake epicenter. More than 1.2 million people lost their homes and many more lost their ways of making a living. The countries that were most affected by the 2004 Boxing Day tsunami. "
a ship at sea will probably not know when a tsunami passes beneath it.,(A) True (B) False,A,"Tsunami are deadly ocean waves from the sharp jolt of an undersea earthquake. Less frequently, these waves can be generated by other shocks to the sea, like a meteorite impact. Fortunately, few undersea earthquakes, and even fewer meteorite impacts, generate tsunami. "
a tsunami wave grows large,(A) As soon as the wave is generated (B) When it combines with large ocean waves (C) When the wave is pushed upward by the shore (D) None of the above,C,"Tsunami waves have small wave heights relative to their long wavelengths, so they are usually unnoticed at sea. When traveling up a slope onto a shoreline, the wave is pushed upward. As with wind waves, the speed of the bottom of the wave is slowed by friction. This causes the wavelength to decrease and the wave to become unstable. These factors can create an enormous and deadly wave. Landslides, meteorite impacts, or any other jolt to ocean water may form a tsunami. Tsunami can travel at speeds of 800 kilometers per hour (500 miles per hour). "
"if you are on a beach and the water rushes out to sea, you should",(A) Follow it to see what is happening (B) Run in the other direction as fast as possible (C) Stay where you are to see what happens next (D) Relax and not worry about it,B,"Like other waves, a tsunami wave has a crest and a trough. When the wave hits the beach, the crest or the trough may come ashore first. When the trough comes in first, water is sucked out to sea. The seafloor just offshore from the beach is exposed. Curious people often walk out onto the beach to see the unusual sight. They drown when the wave crest hits. One amazing story from the Indian Ocean tsunami is that of Tilly Smith. Tilly was a 10-year-old British girl who was visiting Maikhao Beach in Thailand with her parents. Tilly had learned about tsunami in school two weeks before the earthquake. She knew that the receding water and the frothy bubbles at the sea surface meant a tsunami was coming. Tilly told her parents, who told other tourists and the staff at their hotel. The beach was evacuated and no one on Maikhao Beach died. Tilly is credited with saving nearly 100 people! "
tsunami have high wave heights and short wavelengths.,(A) True (B) False,B,"Tsunami waves have small wave heights relative to their long wavelengths, so they are usually unnoticed at sea. When traveling up a slope onto a shoreline, the wave is pushed upward. As with wind waves, the speed of the bottom of the wave is slowed by friction. This causes the wavelength to decrease and the wave to become unstable. These factors can create an enormous and deadly wave. Landslides, meteorite impacts, or any other jolt to ocean water may form a tsunami. Tsunami can travel at speeds of 800 kilometers per hour (500 miles per hour). "
why is the west coast of north america especially vulnerable to tsunami?,(A) A lot of earthquakes happen around the Pacific Ring of Fire (B) The islands of the Pacific (C) like Hawaii (D) have a lot of volcanic activity (E) c The ocean is so big that lots of meteorites can strike it (F) d With all that water (G) the waves can travel faster and grow higher,A,"Since tsunami are long-wavelength waves, a long time can pass between crests or troughs. Any part of the wave can make landfall first. In 1755 in Lisbon, Portugal, a tsunami trough hit land first. A large offshore earthquake did a great deal of damage on land. People rushed out to the open space of the shore. Once there, they discovered that the water was flowing seaward fast and some of them went out to observe. What do you think happened next? The people on the open beach drowned when the crest of the wave came up the beach. Large tsunami in the Indian Ocean and more recently Japan have killed hundreds of thousands of people in recent years. The west coast is vulnerable to tsunami since it sits on the Pacific Ring of Fire. Scientists are trying to learn everything they can about predicting tsunamis before a massive one strikes a little closer to home. Although most places around the Indian Ocean did not have warning systems in 2005, there is a tsunami warning system in that region now. Tsunami warning systems have been placed in most locations where tsunami are possible. Click image to the left or use the URL below. URL: "
tsunami can travel at speeds of,(A) 80 kilometers per hour (B) 800 kilometers per hour (C) 8 kilometers per hour (D) 8000 kilometers per hour,B,"Tsunami waves have small wave heights relative to their long wavelengths, so they are usually unnoticed at sea. When traveling up a slope onto a shoreline, the wave is pushed upward. As with wind waves, the speed of the bottom of the wave is slowed by friction. This causes the wavelength to decrease and the wave to become unstable. These factors can create an enormous and deadly wave. Landslides, meteorite impacts, or any other jolt to ocean water may form a tsunami. Tsunami can travel at speeds of 800 kilometers per hour (500 miles per hour). "
tsunami warnings have been placed where tsunamis are possible.,(A) True (B) False,A,"Most of the Indian Ocean tragedy could have been avoided if a warning system had been in place(Figure 7.32). As of June 2006, the Indian Ocean now has a warning system. Since tsunami are much more common in the Pacific, communities around the Pacific have had a tsunami warning system since 1948. Warning systems arent always helpful. People in communities very close to the earthquake do not have enough time to move inland or uphill. Farther away from the quake, evacuation of low-lying areas saves lives. "
you would be more likely to drown in a tsunami in a flat region than on a steep beach because the wave could travel farther inland and you couldnt outrun it.,(A) True (B) False,A,"Like other waves, a tsunami wave has a crest and a trough. When the wave hits the beach, the crest or the trough may come ashore first. When the trough comes in first, water is sucked out to sea. The seafloor just offshore from the beach is exposed. Curious people often walk out onto the beach to see the unusual sight. They drown when the wave crest hits. One amazing story from the Indian Ocean tsunami is that of Tilly Smith. Tilly was a 10-year-old British girl who was visiting Maikhao Beach in Thailand with her parents. Tilly had learned about tsunami in school two weeks before the earthquake. She knew that the receding water and the frothy bubbles at the sea surface meant a tsunami was coming. Tilly told her parents, who told other tourists and the staff at their hotel. The beach was evacuated and no one on Maikhao Beach died. Tilly is credited with saving nearly 100 people! "
dust is a natural air pollutant that is increased by human activities.,(A) True (B) False,A,"Air quality is a measure of the pollutants in the air. More pollutants mean poorer air quality. Air quality, in turn, depends on many factors. Some natural processes add pollutants to the air. For example, forest fires and volcanoes add carbon dioxide and soot. In dry areas, the air often contains dust. However, human actions cause the most air pollution. The single biggest cause is fossil fuel burning. "
which of these is not a primary pollutant?,(A) Nitrogen oxides (B) Methane from livestock (C) Ozone (D) Particulates,C,"Some primary pollutants are natural, such as volcanic ash. Dust is natural but exacerbated by human activities; for example, when the ground is torn up for agriculture or development. Most primary pollutants are the result of human activities, the direct emissions from vehicles and smokestacks. Primary pollutants include: Carbon oxides include carbon monoxide (CO) and carbon dioxide (CO2 ) (Figure 1.1). Both are colorless, odorless gases. CO is toxic to both plants and animals. CO and CO2 are both greenhouse gases. Nitrogen oxides are produced when nitrogen and oxygen from the atmosphere come together at high temper- atures. This occurs in hot exhaust gas from vehicles, power plants, or factories. Nitrogen oxide (NO) and nitrogen dioxide (NO2 ) are greenhouse gases. Nitrogen oxides contribute to acid rain. Sulfur oxides include sulfur dioxide (SO2 ) and sulfur trioxide (SO3 ). These form when sulfur from burning coal reaches the air. Sulfur oxides are components of acid rain. Particulates are solid particles, such as ash, dust, and fecal matter (Figure 1.2). They are commonly formed from combustion of fossil fuels, and can produce smog. Particulates can contribute to asthma, heart disease, and some types of cancers. Lead was once widely used in automobile fuels, paint, and pipes. This heavy metal can cause brain damage or blood poisoning. High CO2 levels are found in major metropolitan areas and along the major interstate highways. Particulates from a brush fire give the sky a strange glow in Arizona. "
"carbon compounds, such as dioxin and methane, are known as __________.",(A) Volatile inorganic compounds (B) Volatile organic compounds (C) Volatile inorganic carbons (D) Secondary pollutants,B,"Primary pollutants enter the air directly. Some are released by natural processes, like ash from volcanoes. Most are released by human activities. They pour into the air from vehicles and smokestacks. Several of these pollutants are described below. Carbon oxides include carbon monoxide (CO) and carbon dioxide (CO2 ). Carbon oxides are released when fossil fuels burn. Nitrogen oxides include nitric oxide (NO) and nitrogen dioxide (NO2 ). Nitrogen oxides form when nitrogen and oxygen combine at high temperatures. This occurs in hot exhausts from vehicles, factories, and power plants. Sulfur oxides include sulfur dioxide (SO2 ) and sulfur trioxide (SO3 ). Sulfur oxides are produced when sulfur and oxygen combine. This happens when coal burns. Coal can contain up to 10 percent sulfur. Toxic heavy metals include mercury and lead. Mercury is used in some industrial processes. It is also found in fluorescent light bulbs. Lead was once widely used in gasoline, paint, and pipes. It is still found in some products. Volatile organic compounds (VOCs) are carbon compounds such as methane. VOCs are released in many human activities, such as raising livestock. Livestock wastes produce a lot of methane. Particulates are solid particles. These particles may be ash, dust, or even animal wastes. Many are released when fossil fuels burn (see Figure 22.1). "
air pollutants,(A) Muck up the air (B) Cause acid rain (C) Contribute to human health problems (D) All of these,D,"Terrible air pollution events in Pennsylvania and London, in which many people died, plus the recognition of the hazards of photochemical smog, led to the passage of the Clean Air Act in 1970 in the United States. The act now regulates 189 pollutants. The six most important pollutants regulated by the Act are ozone, particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, and the heavy metal lead. Other important regulated pollutants include benzene, perchloroethylene, methylene chloride, dioxin, asbestos, toluene, and metals such as cadmium, mercury, chromium, and lead compounds. What is the result of the Clean Air Act? In short, the air in the United States is much cleaner. Visibility is better and people are no longer incapacitated by industrial smog. However, despite the Act, industry, power plants, and vehicles put 160 million tons of pollutants into the air each year. Some of this smog is invisible and some contributes to the orange or blue haze that affects many cities. "
sulfur oxides and nitrogen oxides are,(A) Ozone destroying compounds (B) Components of acid rain (C) Toxic to human neurological systems (D) All of these,B,"Both nitrogen and sulfur oxides are toxic to humans. These compounds can cause lung diseases or make them worse. Nitrogen and sulfur oxides form acid rain, which is described below. "
"all air pollutants, except particulates, are brownish gases.",(A) True (B) False,B,Most pollutants enter the air when fossil fuels burn. Some are released when forests burn. Others evaporate into the air. 
"secondary pollutants are most common in warm, arid cities surrounded by mountains.",(A) True (B) False,A,"At the same time, many U.S. cities had air pollution problems. Some of the worst were in California. Cars were becoming more popular. Oil refineries and power plants also polluted the air. Mountain ranges trapped polluted air over cities. The California sunshine caused chemical reactions among the pollutants. These reactions produced many more harmful compounds. "
how is ozone created from car exhaust?,(A) Nitrogen oxide from the tailpipe (B) releases an oxygen ion (C) which combines with an (D) b Carbon dioxide from the tailpipe (E) releases an oxygen ion (F) which combines with an oxygen molecule to create O3 (G) c CFCs lose a chlorine ion (H) which breaks apart an oxygen molecule (I) to create two oxygen ions to attach to another oxygen molecule to create O3 (J) d None of the above,A,"Any city can have photochemical smog, but it is most common in sunny, dry locations. A rise in the number of vehicles in cities worldwide has increased photochemical smog. Nitrogen oxides, ozone, and several other compounds are some of the components of this type of air pollution. Photochemical smog forms when car exhaust is exposed to sunlight. Nitrogen oxide is created by gas combustion in cars and then into the air (Figure 1.3). In the presence of sunshine, the NO2 splits and releases an oxygen ion (O). The O then combines with an oxygen molecule (O2 ) to form ozone (O3 ). This reaction can also go in reverse: Nitric oxide (NO) removes an oxygen atom from ozone to make it O2 . The direction the reaction goes depends on how much NO2 and NO there is. If NO2 is three times more abundant than NO, ozone will be produced. If nitric oxide levels are high, ozone will not be created. The brown color of the air behind the Golden Gate Bridge is typical of California cities, because of nitrogen oxides. Ozone is one of the major secondary pollutants. It is created by a chemical reaction that takes place in exhaust and in the presence of sunlight. The gas is acrid-smelling and whitish. Warm, dry cities surrounded by mountains, such as Los Angeles, Phoenix, and Denver, are especially prone to photochemical smog. Photochemical smog peaks at midday on the hottest days of summer. Ozone is also a greenhouse gas. "
"ozone is beneficial in the __________, but a secondary pollutant in the __________.",(A) Mesosphere; troposphere (B) Mesosphere; stratosphere (C) Stratosphere; troposphere (D) Troposphere; stratosphere,C,"At this point you might be asking yourself, Is ozone bad or is ozone good? There is no simple answer to that question: It depends on where the ozone is located (Figure 1.1). In the troposphere, ozone is a pollutant. In the ozone layer in the stratosphere, ozone screens out high energy ultraviolet radiation and makes Earth habitable. "
"when insects are fossilized, it is usually in",(A) Glacial ice (B) Soft sediment (C) Volcanic ash (D) Amber,D,"Despite these problems, there is a rich fossil record. How does an organism become fossilized? A rare insect fossil. "
a fossil frozen into glacial ice may include,(A) Only bones and teeth (B) Bones and teeth (C) plus skin and hair (D) c Bones (E) teeth (F) skin (G) hair (H) plus DNA (I) d Bones (J) teeth (K) skin (L) hair (M) DNA (N) plus liquid blood,C,"Most uncommon is the preservation of soft-tissue original material. Insects have been preserved perfectly in amber, which is ancient tree sap. Mammoths and a Neanderthal hunter were frozen in glaciers, allowing scientists the rare opportunity to examine their skin, hair, and organs. Scientists collect DNA from these remains and compare the DNA sequences to those of modern counterparts. "
"when water deposits minerals into empty spaces to produce a fossil, it is called",(A) Petrified wood (B) Permineralization (C) Replacement (D) Compression,B,"The most common method of fossilization is permineralization. After a bone, wood fragment, or shell is buried in sediment, mineral-rich water moves through the sediment. This water deposits minerals into empty spaces and Five types of fossils: (a) insect preserved in amber, (b) petrified wood (permineralization), (c) cast and mold of a clam shell, (d) pyritized ammonite, and (e) compression fossil of a fern. produces a fossil. Fossil dinosaur bones, petrified wood, and many marine fossils were formed by permineralization. "
a bone dissolves and leaves behind a space called a __________. that space is filled with other materials to form a __________ in the shape of the original organism.,(A) Mold (B) cast (C) b Cast (D) mold (E) c Trace fossil (F) body fossil (G) d Body fossil (H) trace fossil,A,"When the original bone or shell dissolves and leaves behind an empty space in the shape of the material, the depression is called a mold. The space is later filled with other sediments to form a matching cast within the mold that is the shape of the original organism or part. Many mollusks (clams, snails, octopi, and squid) are found as molds and casts because their shells dissolve easily. "
permineralization is the most common method of fossilization.,(A) True (B) False,A,"The most common method of fossilization is permineralization. After a bone, wood fragment, or shell is buried in sediment, mineral-rich water moves through the sediment. This water deposits minerals into empty spaces and Five types of fossils: (a) insect preserved in amber, (b) petrified wood (permineralization), (c) cast and mold of a clam shell, (d) pyritized ammonite, and (e) compression fossil of a fern. produces a fossil. Fossil dinosaur bones, petrified wood, and many marine fossils were formed by permineralization. "
a large mammal fossil that is complete must have formed in exceptional circumstances.,(A) True (B) False,A,"Despite these problems, there is a rich fossil record. How does an organism become fossilized? A rare insect fossil. "
"when the original shell or bone dissolves and the material is substituted for by a different mineral, this is called",(A) Replacement (B) Molds and casts (C) Permineralization (D) None of the above,A,"The original shell or bone dissolves and is replaced by a different mineral. For example, calcite shells may be replaced by dolomite, quartz, or pyrite. If a fossil that has been replace by quartz is surrounded by a calcite matrix, mildly acidic water may dissolve the calcite and leave behind an exquisitely preserved quartz fossil. "
the most common way that fossil leaves are made is by,(A) Replacement (B) Amber (C) Compression (D) Permineralization,C,"Some fossils form when their remains are compressed by high pressure, leaving behind a dark imprint. Compression is most common for fossils of leaves and ferns, but can occur with other organisms. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
there are many fossils of bacteria and jellyfish.,(A) True (B) False,B,"Some rock beds contain exceptional fossils or fossil assemblages. Two of the most famous examples of soft organism preservation are from the 505 million-year-old Burgess Shale in Canada (Figure 1.8). The 145 million-year-old Solnhofen Limestone in Germany has fossils of soft body parts that are not normally preserved (Figure 1.8). (a) The Burgess shale contains soft-bodied fossils. (b) Anomalocaris, meaning abnormal shrimp is now extinct. The image is of a fossil. (c) The famous Archeopteryx fossil from the Solnhofen Limestone has distinct feathers and was one of the earliest birds. Click image to the left or use the URL below. URL: "
to create petrified wood,(A) A piece of wood is compressed by the weight of overlying sediments (B) A piece of wood dissolves and the hole is filled with sediments that resemble it (C) A piece of wood dissolves and is replaced by a mineral (D) A buried piece of wood is filled with minerals that are deposited into the empty spaces,D,"The most common method of fossilization is permineralization. After a bone, wood fragment, or shell is buried in sediment, mineral-rich water moves through the sediment. This water deposits minerals into empty spaces and Five types of fossils: (a) insect preserved in amber, (b) petrified wood (permineralization), (c) cast and mold of a clam shell, (d) pyritized ammonite, and (e) compression fossil of a fern. produces a fossil. Fossil dinosaur bones, petrified wood, and many marine fossils were formed by permineralization. "
"everything we can see, even through our most advanced telescopes is in",(A) Our solar system (B) The Local Group (C) The Milky Way Galaxy (D) The Universe,D,"Galileos telescope got people to think about the solar system in the right way. Modern tools have also transformed our way of thinking about the universe. Imagine this: Today you can see all of the things Galileo saw using a good pair of binoculars. You can see sunspots if you have special filters on the lenses. (Never look directly at the Sun without using the proper filters!) With the most basic telescope, you can see polar caps on Mars, the rings of Saturn, and bands in the atmosphere of Jupiter. You can see many times more stars with a telescope than without a telescope. Still, stars seen in a telescope look like single points of light. They are so far away. Only the red supergiant star Betelgeuse is large enough to appear as a disk. Except for our Sun, of course. Today, astronomers attach special instruments to telescopes. This allows them to collect a wide variety of data. The data is fed into computers so that it can be studied. An astronomer may take weeks to analyze all of the data collected from just a single night! "
galileos telescope gave evidence that _______________.,(A) Earth is the center of the solar system (B) The Sun is the center of the solar system (C) A black hole is the center of the solar system (D) None of the above,B,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
the ancient greeks thought the universe had __________ at the center and a sphere to which __________ were attached.,(A) Earth; the Sun (B) Moon (C) five planets and stars (D) b Sun; the six planets and stars (E) c A black hole; the entire universe (F) d None of the above,A,"The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD. "
edwin hubble was the first to realize that the andromeda nebula was another _________________ outside __________.,(A) Solar system; our solar system (B) Universe; our universe (C) Nebula; our nebula (D) Galaxy; out Milky Way galaxy,D,"What did the ancient Greeks recognize as the universe? In their model, the universe contained Earth at the center, the Sun, the Moon, five planets, and a sphere to which all the stars were attached. This idea held for many centuries until Galileos telescope helped people recognize that Earth is not the center of the universe. They also found out that there are many more stars than were visible to the naked eye. All of those stars were in the Milky Way Galaxy. In the early 20th century, an astronomer named Edwin Hubble (Figure 1.1) discovered that what scientists called the Andromeda Nebula was actually over 2 million light years away  many times farther than the farthest distances that had ever been measured. Hubble realized that many of the objects that astronomers called nebulas were not actually clouds of gas, but were collections of millions or billions of stars  what we now call galaxies. Hubble showed that the universe was much larger than our own galaxy. Today, we know that the universe contains about a hundred billion galaxies  about the same number of galaxies as there are stars in the Milky Way Galaxy. (a) Edwin Hubble used the 100-inch reflecting telescope at the Mount Wilson Observatory in California to show that some distant specks of light were galaxies. (b) Hubbles namesake space telescope spotted this six galaxy group. Edwin Hubble demonstrated the existence of galaxies. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
galileos telescope revealed galaxies that were not visible with the naked eye.,(A) True (B) False,B,"In 1610, Galileo looked at the night sky through the first telescope. This tool allowed him to make the following discoveries (among others): There are more stars in the night sky than the unaided eye can see. The band of light called the Milky Way consists of many stars. The Moon has craters (see Figure 23.10). Venus has phases like the Moon. Jupiter has moons orbiting around it. There are dark spots that move across the surface of the Sun. Galileos observations made people think differently about the universe. They made them think about the solar system and Earths place in it. Until that time, people believed that the Sun and planets revolved around Earth. One hundred years before Galileo, Copernicus had said that the Earth and the other planets revolved around the Sun. No one would believe him. But Galileos observations through his telescope proved that Copernicus was right. "
"during the time of galileo, most people thought that earth was the center of the universe.",(A) True (B) False,A,"About 1,500 years after Ptolemy, Copernicus proposed a startling idea. He suggested that the Sun is at the center of the universe. Copernicus developed his model because it better explained the motions of the planets. Figure 25.2 shows both the Earth-centered and Sun-centered models. Copernicus did not publish his new model until his death. He knew that it was heresy to say that Earth was not the center of the universe. It wasnt until Galileo developed his telescope that people would take the Copernican "
the idea that there may be more than one universe is called the _____________.,(A) Multiverse Theory (B) Big bang Hypothesis (C) Multiverse Hypothesis (D) Big Bang Theory,C,"The study of the universe is called cosmology. Cosmologists study the structure and changes in the present universe. The universe contains all of the star systems, galaxies, gas, and dust, plus all the matter and energy that exists now, that existed in the past, and that will exist in the future. The universe includes all of space and time. "
"edwin hubble found out that what appeared to be large clouds in space were not gas, but",(A) Large stars (B) Galaxies (C) The Oort cloud (D) The Kuiper belt,B,"What did the ancient Greeks recognize as the universe? In their model, the universe contained Earth at the center, the Sun, the Moon, five planets, and a sphere to which all the stars were attached. This idea held for many centuries until Galileos telescope helped people recognize that Earth is not the center of the universe. They also found out that there are many more stars than were visible to the naked eye. All of those stars were in the Milky Way Galaxy. In the early 20th century, an astronomer named Edwin Hubble (Figure 1.1) discovered that what scientists called the Andromeda Nebula was actually over 2 million light years away  many times farther than the farthest distances that had ever been measured. Hubble realized that many of the objects that astronomers called nebulas were not actually clouds of gas, but were collections of millions or billions of stars  what we now call galaxies. Hubble showed that the universe was much larger than our own galaxy. Today, we know that the universe contains about a hundred billion galaxies  about the same number of galaxies as there are stars in the Milky Way Galaxy. (a) Edwin Hubble used the 100-inch reflecting telescope at the Mount Wilson Observatory in California to show that some distant specks of light were galaxies. (b) Hubbles namesake space telescope spotted this six galaxy group. Edwin Hubble demonstrated the existence of galaxies. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
astronomers think that the universe contains about 100 billion galaxies.,(A) True (B) False,A,"The Milky Way Galaxy is a spiral galaxy that contains about 400 billion stars. Like other spiral galaxies, it has a disk, a central bulge, and spiral arms. The disk is about 100,000 light-years across. It is about 3,000 light years thick. Most of the galaxys gas, dust, young stars, and open clusters are in the disk. Some astronomers think that there is a gigantic black hole at the center of the galaxy. Figure 26.13 shows what the Milky Way probably looks like from the outside. Our solar system is within one of the spiral arms. Most of the stars we see in the sky are relatively nearby stars that are also in this spiral arm. We are a little more than halfway out from the center of the Galaxy to the edge, as shown in Figure 26.13. Our solar system orbits the center of the galaxy as the galaxy spins. One orbit of the solar system takes about 225 to 250 million years. The solar system has orbited 20 to 25 times since it formed 4.6 billion years ago. "
who first discovered uranus?,(A) Galileo Galilei (B) William Herschel (C) Johannes Kepler (D) Ancient shepherds,B,"Uranus, shown in Figure 25.26, is named for the Greek god of the sky, the father of Saturn. Astronomers pronounce the name YOOR-uh-nuhs. Uranus was not known to ancient observers. The planet was first discovered with a telescope by the astronomer William Herschel in 1781. Uranus is faint because it is very far away. Its distance from the Sun is 2.8 billion kilometers (1.8 billion miles). A photon from the Sun takes about 2 hours and 40 minutes to reach Uranus. Uranus orbits the Sun once about every 84 Earth years. "
"in the planetary lineup, uranus is",(A) #7 (B) 3rd from the outermost (C) Just before Pluto (D) Right after Mars,A,"Uranus, shown in Figure 25.26, is named for the Greek god of the sky, the father of Saturn. Astronomers pronounce the name YOOR-uh-nuhs. Uranus was not known to ancient observers. The planet was first discovered with a telescope by the astronomer William Herschel in 1781. Uranus is faint because it is very far away. Its distance from the Sun is 2.8 billion kilometers (1.8 billion miles). A photon from the Sun takes about 2 hours and 40 minutes to reach Uranus. Uranus orbits the Sun once about every 84 Earth years. "
"if your grandfather is 73 years old, he has been alive for one year on uranus.",(A) True (B) False,B,"Uranus, shown in Figure 25.26, is named for the Greek god of the sky, the father of Saturn. Astronomers pronounce the name YOOR-uh-nuhs. Uranus was not known to ancient observers. The planet was first discovered with a telescope by the astronomer William Herschel in 1781. Uranus is faint because it is very far away. Its distance from the Sun is 2.8 billion kilometers (1.8 billion miles). A photon from the Sun takes about 2 hours and 40 minutes to reach Uranus. Uranus orbits the Sun once about every 84 Earth years. "
the composition of uranus is,(A) The same as Saturn and Jupiter (B) The same as Neptune (C) Higher in ices (D) such as water (E) ammonia and methane (F) d Higher in carbon dioxide and nitrogen,C,"Like Jupiter and Saturn, Uranus is composed mainly of hydrogen and helium, with an outer gas layer that gives way to liquid on the inside. Uranus has a higher percentage of icy materials, such as water, ammonia (NH3 ), and methane (CH4 ), than Jupiter and Saturn. When sunlight reflects off Uranus, clouds of methane filter out red light, giving the planet a blue-green color. There are bands of clouds in the atmosphere of Uranus, but they are hard to see in normal light, so the planet looks like a plain blue ball. "
uranus is a blue-green color because,(A) Clouds of carbon dioxide filter out the red light (B) Clouds of carbon dioxide filter out the blue and green light (C) Clouds of methane filter out the red light (D) Clouds of methane filter out the blue and green light,C,"Like Jupiter and Saturn, Uranus is composed mainly of hydrogen and helium, with an outer gas layer that gives way to liquid on the inside. Uranus has a higher percentage of icy materials, such as water, ammonia (NH3 ), and methane (CH4 ), than Jupiter and Saturn. When sunlight reflects off Uranus, clouds of methane filter out red light, giving the planet a blue-green color. There are bands of clouds in the atmosphere of Uranus, but they are hard to see in normal light, so the planet looks like a plain blue ball. "
gravity is stronger on uranus than earth.,(A) True (B) False,B,"Uranus (YOOR-uh-nuhs) is named for the Greek god of the sky. From Earth, Uranus is so faint that it was unnoticed by ancient observers. William Herschel first discovered the planet in 1781. Although Uranus is very large, it is extremely far away, about 2.8 billion km (1.8 billion mi) from the Sun. Light from the Sun takes about 2 hours and 40 minutes to reach Uranus. Uranus orbits the Sun once about every 84 Earth years. Uranus has a mass about 14 times the mass of Earth, but it is much less dense than Earth. Gravity at the surface of Uranus is weaker than on Earths surface, so if you were at the top of the clouds on Uranus, you would weigh about 10% less than what you weigh on Earth. "
uranus is unusual among the outer planets because,(A) It is tilted on its side (B) Its rings are the same color as the planet (C) It doesn’t have any moons (D) All of these,A,"Uranus is a lot like Jupiter and Saturn. The planet is composed mainly of hydrogen and helium. There is a thick layer of gas on the outside. Further on the inside is liquid. But Uranus has a higher percentage of icy materials than Jupiter and Saturn. These materials include water, ammonia, and methane. Uranus is also different because of its blue-green color. Clouds of methane filter out red light. This leaves a blue-green color. The atmosphere of Uranus has bands of clouds. These clouds are hard to see in normal light. The result is that the planet looks like a plain blue ball. Uranus is the least massive outer planet. Its mass is only about 14 times the mass of Earth. Like all of the outer planets, Uranus is much less dense than Earth. Gravity is actually weaker than on Earths surface. If you were at the top of the clouds on Uranus, you would weigh about 10 percent less than what you weigh on Earth. "
"uranus has _____ known moons, most of which are named for characters from __________.",(A) 33; CS Lewis (B) 23; Lord of the Rings (C) 15; Harry Potter (D) 27; Shakespeare,D,"Uranus has a faint system of rings (Figure 1.1). The rings circle the planets equator, but because Uranus is tilted on its side, the rings are almost perpendicular to the planets orbit. This image from the Hubble Space Tele- scope shows the faint rings of Uranus. The planet is tilted on its side, so the rings are nearly vertical. Uranus has 27 known moons and all but a few of them are named for characters from the plays of William Shakespeare. The five biggest moons of Uranus  Miranda, Ariel, Umbriel, Titania, and Oberon  are shown in Figure 1.2. These Voyager 2 photos have been resized to show the relative sizes of the five main moons of Uranus. Click image to the left or use the URL below. URL: "
uranus may have been hit by struck by an enormous object billions of years ago.,(A) True (B) False,A,All of the planets rotate on their axes in the same direction that they move around the Sun. Except for Uranus. Uranus is tilted on its side. Its axis is almost parallel to its orbit. So Uranus rolls along like a bowling ball as it revolves around the Sun. How did Uranus get this way? Scientists think that the planet was struck and knocked over by another planet-sized object. This collision probably took place billions of years ago. 
uranus rings,(A) Circle the planet’s poles (B) Are almost vertical (C) Are visible from Earth with a very good telescope (D) All of these,B,"Uranus has a faint system of rings (Figure 1.1). The rings circle the planets equator, but because Uranus is tilted on its side, the rings are almost perpendicular to the planets orbit. This image from the Hubble Space Tele- scope shows the faint rings of Uranus. The planet is tilted on its side, so the rings are nearly vertical. Uranus has 27 known moons and all but a few of them are named for characters from the plays of William Shakespeare. The five biggest moons of Uranus  Miranda, Ariel, Umbriel, Titania, and Oberon  are shown in Figure 1.2. These Voyager 2 photos have been resized to show the relative sizes of the five main moons of Uranus. Click image to the left or use the URL below. URL: "
humans use this much more water today as they did 100 years ago.,(A) Twice as much (B) Three times as much (C) Six times as much (D) Sixteen times as much,C,Humans use six times as much water today as they did 100 years ago. People living in developed countries use a far greater proportion of the worlds water than people in less developed countries. What do people use all of that water for? 
aquaculture of large fish does damage by,(A) Converting natural ecosystems to fish farms (B) Putting wild fish at risk for disease and parasites (C) Taking a lot of food energy to create its product (D) All of the above,D,"For some species, aquaculture is very successful and environmental harm is minimal. But for other species, aqua- culture can cause problems. Natural landscapes, such as mangroves, which are rich ecosystems and also protect coastlines from storm damage, may be lost to fish farms (Figure 1.4). For fish farmers, keeping costs down may be a problem since coastal land may be expensive and labor costs may be high. Large predatory fish at the 4th or 5th trophic level must eat a lot, so feeding large numbers of these fish is expensive and environmentally costly. Farmed fish are genetically different from wild stocks, and if they escape into the wild they may cause problems for native fish. Because the organisms live so close together, parasites are common and may also escape into the wild. Shrimp farms on the coast of Ecuador are shown as blue rectangles. Mangrove forests, salt flats, and salt marshes have been converted to shrimp farms. "
water that can be recycled and reused is called ____________water use.,(A) Non-consumptive (B) Consumptive (C) Non-commercial (D) Commercial,A,"Lets now look at what we can reuse. Reusing includes using the same item again for the same function and also using an item again for a new function. Reuse can have both economic and environmental benefits. New packaging regulations are helping society to move towards these goals. Water is a resource that can be reused for numerous purposes. You may not drink used water, but it is quite useful for other purposes. Some ways of reusing resources include: Use reusable bags when shopping. Use gray water. Water that has been used for laundry, for example, can be used to water the garden or flush toilets. At the town level, purified sewage water can be used for fountains, watering public parks or golf courses, fire fighting, and irrigating crops. Rain can be caught in rain barrels and used to water your garden. What are some other ways to reuse resources? "
to decrease the amount of water you use in your household you could,(A) Use drip irrigation (B) Install low-flow shower heads and toilets (C) Reduce the amount of time you take in the shower (D) All of these,D,"Think about all the ways you use water in a day. You need to count the water you drink, cook with, bathe in, garden with, let run down the drain, or flush down the toilet. In developed countries, people use a lot of water, while in less developed countries people use much less. Globally, household or personal water use is estimated to account for 15% of world-wide water use. Some household water uses are non-consumptive, because water is recaptured in sewer systems, treated, and returned to surface water supplies for reuse. Many things can be done to lower water consumption at home. Convert lawns and gardens to drip-irrigation systems. Install low-flow shower heads and low-flow toilets. In what other ways can you use less water at home? "
drip irrigation is better than other types of irrigation because,(A) It is more efficient (B) It costs less (C) There is little evaporation and runoff (D) All of the above,D,"A much more efficient way to water crops is drip irrigation (Figure 1.2). With drip irrigation, pipes and tubes deliver small amounts of water directly to the soil at the roots of each plant or tree. The water is not sprayed into the air or over the ground, so nearly all of it goes directly into the soil and plant roots. "
"industrial water use includes using water for cooling, but not using up the water.",(A) True (B) False,A,"Industrial water use accounts for an estimated 15% of worldwide water use, with a much greater percentage in developed nations. Industrial uses of water include power plants that use water to cool their equipment and oil refineries that use water for chemical processes. Manufacturing is also water intensive. "
recreational uses of water,(A) Make up a large part of the water use in developed countries (B) Can be extremely wasteful of water (C) Are all non-consumptive (D) Are not a good use of water,B,"People love water for swimming, fishing, boating, river rafting, and other activates. Even activities such as golf, where there may not be any standing water, require plenty of water to make the grass on the course green. Despite its value, the amount of water that most recreational activities use is low: less than 1% of all the water we use. Many recreational water uses are non-consumptive including swimming, fishing, and boating. Golf courses are the biggest recreational water consumer since they require large amounts for irrigation, especially because many courses are located in warm, sunny, desert regions where water is scarce and evaporation is high. "
which is not a feature of environmental uses of water?,(A) They account for a large portion of the water use in developed countries (B) They are non-consumptive (C) They increase or maintain biodiversity (D) They provide habitat for fish and water birds,A,Environmental use of water includes creating wildlife habitat. Lakes are built to create places for fish and water birds (Figure 1.5). Most environmental uses are non-consumptive and account for an even smaller percentage of water use than recreational uses. A shortage of this water is a leading cause of global biodiversity loss. Click image to the left or use the URL below. URL: 
"overhead sprinklers, trench irrigation, and flood irrigation are wasteful because",(A) A lot of the water evaporates (B) A love of the water runs off the fields without being used (C) The water is not directed to the plants that needed (D) A & B,D,"Why do farmers use wasteful irrigation methods when water-efficient methods are available? Many farmers and farming corporations have not switched to more efficient irrigation methods for two reasons: 1. Drip irrigation and other more efficient irrigation methods are more expensive than sprinklers, trenches, and flooding. 2. In the United States and some other countries, the government pays for much of the cost of the water that is used for agriculture. Because farmers do not pay the full cost of their water use, they do not have any financial incentive to use less water. What ideas can you come up with to encourage farmers to use more efficient irrigation systems? "
aquaculture of some species provides a lot of food value at little environmental cost.,(A) True (B) False,A,"For some species, aquaculture is very successful and environmental harm is minimal. But for other species, aqua- culture can cause problems. Natural landscapes, such as mangroves, which are rich ecosystems and also protect coastlines from storm damage, may be lost to fish farms (Figure 1.4). For fish farmers, keeping costs down may be a problem since coastal land may be expensive and labor costs may be high. Large predatory fish at the 4th or 5th trophic level must eat a lot, so feeding large numbers of these fish is expensive and environmentally costly. Farmed fish are genetically different from wild stocks, and if they escape into the wild they may cause problems for native fish. Because the organisms live so close together, parasites are common and may also escape into the wild. Shrimp farms on the coast of Ecuador are shown as blue rectangles. Mangrove forests, salt flats, and salt marshes have been converted to shrimp farms. "
earths nearest planetary neighbor and closest in size and density is __________.,(A) Jupiter (B) Pluto (C) Uranus (D) None of the above,D,"Ceres is by far the closest dwarf planet to the Sun; it resides between Mars and Jupiter. Ceres is the largest object in the asteroid belt (Figure 1.2). Before 2006, Ceres was considered the largest of the asteroids, with only about 1.3% of the mass of the Earths Moon. But unlike the asteroids, Ceres has enough mass that its gravity causes it to be shaped like a sphere. Like Pluto, Ceres is rocky. Is Ceres a planet? How does it match the criteria above? Ceres orbits the Sun, is round, and is not a moon. As part of the asteroid belt, its orbit is full of other smaller bodies, so Ceres fails the fourth criterion for being a planet. "
venus has a core made of ______ and a mantle made of _______.,(A) Iron; Silicate (B) Iron; Silicone (C) Silver: Iron (D) None of the above,A,"The two most important things about the mantle are: (1) it is made of solid rock, and (2) it is hot. "
clouds on venus are made of,(A) Water vapor like on Earth (B) Acid (C) Carbon dioxide and a bit of sulfur dioxide (D) Methane and ozone,C,"Venus is covered by a thick layer of clouds, as shown in pictures of Venus taken at ultraviolet wavelengths (Figure This ultraviolet image from the Pioneer Venus Orbiter shows thick layers of clouds in the atmosphere of Venus. Venus clouds are not made of water vapor like Earths clouds. Clouds on Venus are made mostly of carbon dioxide Click image to the left or use the URL below. URL:  The atmosphere of Venus is so thick that the atmospheric pressure on the planets surface is 90 times greater than the atmospheric pressure on Earths surface. The dense atmosphere totally obscures the surface of Venus, even from spacecraft orbiting the planet. "
venus orbits the sun __________ than earth and rotates on its axis __________.,(A) Faster; slowly (B) Faster; quickly (C) Slower; slowly (D) Slower; quickly,A,"Venus rotates in a direction opposite the other planets and opposite to the direction it orbits the Sun. This rotation is extremely slow, only one turn every 243 Earth days. This is longer than a year on Venus  it takes Venus only 224 days to orbit the Sun. Diagram of Venuss interior, which is simi- lar to Earths. "
scientists could learn a lot about the surface of venus through telescopes since the planet is so close.,(A) True (B) False,B,"Viewed through a telescope, Venus looks smooth and featureless. The planet is covered by a thick layer of clouds. You can see the clouds in pictures of Venus, such as Figure 25.11. We make maps of the surface using radar, because the thick clouds wont allow us to take photographs of the surface of Venus. Figure 25.12 shows the topographical features of Venus. The image was produced by the Magellan probe on a flyby. Radar waves sent by the spacecraft reveal mountains, valleys, vast lava plains, and canyons. Like Mercury, Venus does not have a moon. Clouds on Earth are made of water vapor. Venuss clouds are a lot less pleasant. They are made of carbon dioxide, sulfur dioxide and large amounts of corrosive sulfuric acid! The atmosphere of Venus is so thick that the pressure on the surface of Venus is very high. In fact, it is 90 times greater than the pressure at Earths surface! The thick atmosphere causes a strong greenhouse effect. As a result, Venus is the hottest planet. Even though it is farther from the Sun, Venus is much hotter even than Mercury. Temperatures at the surface reach 465C (860F). Thats hot enough to melt lead! "
venus has extremely high atmospheric pressure and an intense greenhouse effect.,(A) True (B) False,A,"Venus is covered by a thick layer of clouds, as shown in pictures of Venus taken at ultraviolet wavelengths (Figure This ultraviolet image from the Pioneer Venus Orbiter shows thick layers of clouds in the atmosphere of Venus. Venus clouds are not made of water vapor like Earths clouds. Clouds on Venus are made mostly of carbon dioxide Click image to the left or use the URL below. URL:  The atmosphere of Venus is so thick that the atmospheric pressure on the planets surface is 90 times greater than the atmospheric pressure on Earths surface. The dense atmosphere totally obscures the surface of Venus, even from spacecraft orbiting the planet. "
volcanism on venus,(A) Is due to plate tectonics (B) Occurs when too much heat builds up below the surface (C) Has not occurred for around 4 billion years (D) All of these,B,"Venus has more volcanoes than any other planet. There are between 100,000 and one million volcanoes on Venus! Most of the volcanoes are now inactive. There are also a large number of craters. This means that Venus doesnt have tectonic plates. Plate tectonics on Earth erases features over time. Figure 25.13 is an image made using radar data. The volcano is Maat Mons. Lava beds are in the foreground. Scientists think the color of sunlight on Venus is "
a topographical map of venus reveals,(A) Mountains and valleys (B) Large plains of lava (C) Volcanoes (D) All of the above,D,"Since spacecraft cannot see through the thick atmosphere, radar is used to map Venus surface. Many features found on the surface are similar to Earth and yet are very different. Figure 1.3 shows a topographical map of Venus produced by the Magellan probe using radar. This false color image of Venus was made from radar data collected by the Magellan probe between 1990 and 1994. What features can you identify? Most of the volcanoes are no longer active, but scientists have found evidence that there is some active volcanism (Figure 1.4). Think about what you know about the geology of Earth and what produces volcanoes. What does the presence of volcanoes suggest about the geology of Venus? What evidence would you look for to find the causes of volcanism on Venus? This image of the Maat Mons volcano with lava beds in the foreground was gen- erated by a computer from radar data. The reddish-orange color is close to what scientists think the color of sunlight would look like on the surface of Venus. Venus also has very few impact craters compared with Mercury and the Moon. What is the significance of this? Earth has fewer impact craters than Mercury and the Moon, too. Is this for the same reason that Venus has fewer impact craters? Its difficult for scientists to figure out the geological history of Venus. The environment is too harsh for a rover to go there. It is even more difficult for students to figure out the geological history of a distant planet based on the information given here. Still, we can piece together a few things. On Earth, volcanism is generated because the planets interior is hot. Much of the volcanic activity is caused by plate tectonic activity. But on Venus, there is no evidence of plate boundaries and volcanic features do not line up the way they do at plate boundaries. Because the density of impact craters can be used to determine how old a planets surface is, the small number of impact craters means that Venus surface is young. Scientists think that there is frequent, planet-wide resurfacing of Venus with volcanism taking place in many locations. The cause is heat that builds up below the surface, which has no escape until finally it destroys the crust and results in volcanoes. Click image to the left or use the URL below. URL: "
scientists know that venus surface,(A) Is very young (B) Has few impact craters compared with Mercury and the Moon (C) Shows a lot of recent volcanic activity (D) All of these,D,"Since spacecraft cannot see through the thick atmosphere, radar is used to map Venus surface. Many features found on the surface are similar to Earth and yet are very different. Figure 1.3 shows a topographical map of Venus produced by the Magellan probe using radar. This false color image of Venus was made from radar data collected by the Magellan probe between 1990 and 1994. What features can you identify? Most of the volcanoes are no longer active, but scientists have found evidence that there is some active volcanism (Figure 1.4). Think about what you know about the geology of Earth and what produces volcanoes. What does the presence of volcanoes suggest about the geology of Venus? What evidence would you look for to find the causes of volcanism on Venus? This image of the Maat Mons volcano with lava beds in the foreground was gen- erated by a computer from radar data. The reddish-orange color is close to what scientists think the color of sunlight would look like on the surface of Venus. Venus also has very few impact craters compared with Mercury and the Moon. What is the significance of this? Earth has fewer impact craters than Mercury and the Moon, too. Is this for the same reason that Venus has fewer impact craters? Its difficult for scientists to figure out the geological history of Venus. The environment is too harsh for a rover to go there. It is even more difficult for students to figure out the geological history of a distant planet based on the information given here. Still, we can piece together a few things. On Earth, volcanism is generated because the planets interior is hot. Much of the volcanic activity is caused by plate tectonic activity. But on Venus, there is no evidence of plate boundaries and volcanic features do not line up the way they do at plate boundaries. Because the density of impact craters can be used to determine how old a planets surface is, the small number of impact craters means that Venus surface is young. Scientists think that there is frequent, planet-wide resurfacing of Venus with volcanism taking place in many locations. The cause is heat that builds up below the surface, which has no escape until finally it destroys the crust and results in volcanoes. Click image to the left or use the URL below. URL: "
"venus is the 2nd hottest planet in the solar system, after mercury.",(A) True (B) False,B,"Venus thick clouds reflect sunlight well, so Venus is very bright. When it is visible, Venus is the brightest object in the sky besides the Sun and the Moon. Because the orbit of Venus is inside Earths orbit, Venus always appears close to the Sun. When Venus rises just before the Sun rises, the bright object is called the morning star. When it sets just after the Sun sets, it is the evening star. Of the planets, Venus is most similar to Earth in size and density. Venus is also our nearest neighbor. The planets interior structure is similar to Earths, with a large iron core and a silicate mantle (Figure 1.1). But the resemblance between the two inner planets ends there. "
water may cause the next war because,(A) Large regions receive much less water relative to their population (B) Water breakdown is a new alternative energy source (C) Developed nations use so much water that they need to get it from underdeveloped nations (D) None of these,A,"As water supplies become scarce, conflicts will arise between the individuals or nations that have enough clean water and those that do not (Figure 1.3). Some of todays greatest tensions are happening in places where water is scarce. Water disputes may add to tensions between countries where differing national interests and withdrawal rights have been in conflict. Just as with energy resources today, wars may erupt over water. Water disputes are happening along 260 different river systems that cross national boundaries. Some of these disputes are potentially very serious. International water laws, such as the Helsinki Rules, help interpret water rights among countries. Many regions already experience water scarcity. This map shows the number of months in which the amount of water that is used exceeds the availability of water that can be used sustainably. This is projected to get worse as demand increases. "
which of the following is not true about water scarcity?,(A) In 1995 (B) about 40% of the world’s population faced water scarcity (C) b use in a year (D) c People in water scarcity die from thirst (E) hunger and diseases more than other people (F) d Water scarcity is defined as the state in which people do not have enough water to meet,D,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
a region is said to be in drought when,(A) It receives an average of less than 10-inches of rain each year for months or years (B) Plants die and the ground dries out (C) It experiences low precipitation for that region for months or years (D) Animals die of thirst and lack food,C,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
the central valley of california is a lush agricultural area because it receives a lot of rain.,(A) True (B) False,B,"Placer minerals collect in stream gravels. They can be found in modern rivers or ancient riverbeds. California was nicknamed the Golden State. This can be traced back to the discovery of placer gold in 1848. The amount of placer gold brought in miners from around the world. The gold formed in rocks in the Sierra Nevada Mountains. The rocks also contained other valuable minerals. The gold weathered out of the hard rock. It washed downstream and then settled in gravel deposits along the river. Currently, California has active gold and silver mines. California also has mines for non-metal minerals. For example, sand and gravel are mined for construction. "
a change in temperature and precipitation would completely change the types of plants and animals in a region.,(A) True (B) False,A,"Global warming will change patterns of rainfall and water distribution. As the Earth warms, regions that currently receive an adequate supply of rain may shift. Regions that rely on snowmelt may find that there is less snow and the melt comes earlier and faster in the spring, causing the water to run off and not be available through the dry summers. A change in temperature and precipitation would completely change the types of plants and animals that can live successfully in that region. "
which of these is not a possible effect of global warming?,(A) Patterns of rainfall may change so that agricultural land may no longer get enough rain (B) Snowmelt may no longer be available to get water to a region through a long (C) hot summer (D) c The plants and animals that live in the region may die out or shift locations (E) d All of the planet will experience drought at the same time,D,"The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: "
water scarcity is,(A) A region not receiving enough rain (B) A region not receiving enough water to meet its people’s needs (C) A region that chops down all of its trees (D) A region that goes to war over water,B,"Water scarcity is a problem now and will become an even larger problem in the future as water sources are reduced or polluted and population grows. In 1995, about 40% of the worlds population faced water scarcity. Scientists estimate that by the year 2025, nearly half of the worlds people wont have enough water to meet their daily needs. Nearly one-quarter of the worlds people will have less than 500 m3 of water to use in an entire year. That amount is less water in a year than some people in the United States use in one day. Some regions have very little rainfall per month. "
"some regions receive a considerable amount of rain, but have an annual drought of several months each year.",(A) True (B) False,A,"Droughts also depend on what is normal for a region. When a region gets significantly less precipitation than normal for an extended period of time, it is in drought. The Southern United States is experiencing an ongoing and prolonged drought. Drought has many consequences. When soil loses moisture it may blow away, as happened during the Dust Bowl in the United States in the 1930s. Forests may be lost, dust storms may become common, and wildlife are disturbed. Wildfires become much more common during times of drought. "
water disputes are easily solved using the helsinki rules.,(A) True (B) False,B,"As water supplies become scarce, conflicts will arise between the individuals or nations that have enough clean water and those that do not (Figure 1.3). Some of todays greatest tensions are happening in places where water is scarce. Water disputes may add to tensions between countries where differing national interests and withdrawal rights have been in conflict. Just as with energy resources today, wars may erupt over water. Water disputes are happening along 260 different river systems that cross national boundaries. Some of these disputes are potentially very serious. International water laws, such as the Helsinki Rules, help interpret water rights among countries. Many regions already experience water scarcity. This map shows the number of months in which the amount of water that is used exceeds the availability of water that can be used sustainably. This is projected to get worse as demand increases. "
water pollution can affect,(A) Availability of safe drinking water (B) Human health (C) Waterborne diseases (D) All of the above,D,"Water pollutants can have an effect on both the ecology of ecosystems and on humans. As a result of water pollution, humans may not be able to use a waterway for recreation and fishing. Drinking water can also be affected if a toxin enters the groundwater. "
"contaminants such as radioactive substances, toxic chemicals and petroleum come from __________.",(A) Homes (B) Farms (C) Industries (D) None of the above,C,"Factories and hospitals spew pollutants into the air and waterways (Figure 1.2). Some of the most hazardous industrial pollutants include: Radioactive substances from nuclear power plants and medical and scientific sources. Heavy metals, organic toxins, oils, and solids in industrial waste. Chemicals, such as sulfur, from burning fossil fuels. Oil and other petroleum products from supertanker spills and offshore drilling accidents. Heated water from industrial processes, such as power stations. "
"in some underdeveloped countries, raw sewage is dumped into the same water where people drink and bathe.",(A) True (B) False,A,"Water pollution contributes to water shortages by making some water sources unavailable for use. In underdeveloped countries, raw sewage is dumped into the same water that people drink and bathe in. Even in developed countries, water pollution affects human and environmental health. Water pollution includes any contaminant that gets into lakes, streams, and oceans. The most widespread source of water contamination in developing countries is raw sewage. In developed countries, the three main sources of water pollution are described below. "
water pollution is not a problem in developed nations.,(A) True (B) False,B,"Water pollution contributes to water shortages by making some water sources unavailable for use. In underdeveloped countries, raw sewage is dumped into the same water that people drink and bathe in. Even in developed countries, water pollution affects human and environmental health. Water pollution includes any contaminant that gets into lakes, streams, and oceans. The most widespread source of water contamination in developing countries is raw sewage. In developed countries, the three main sources of water pollution are described below. "
"in the united states, sewage that enters water bodies is always decontaminated and cleaned up.",(A) True (B) False,B,"In the U.S., concern over water pollution has resulted in many federal laws. Some of these laws go all the way back to the 1800s! The laws prohibit the disposal of any waste into the nations rivers, lakes, streams, and other bodies of water, unless a person first has a permit. Growing concern for controlling water pollutants led to the enactment of the Clean Water Act in 1972. The Clean Water Act set water quality standards. It also limits the pollution that can enter the waterways. Other countries are also actively preventing water pollution and purifying water ( Figure 1.1). A water purification station in France. Contaminants are removed to make clean water. "
which of the following is not a hazardous industrial pollutant?,(A) heat (B) raw sewage (C) heavy metals (D) radioactive substances,B,"Factories and hospitals spew pollutants into the air and waterways (Figure 1.2). Some of the most hazardous industrial pollutants include: Radioactive substances from nuclear power plants and medical and scientific sources. Heavy metals, organic toxins, oils, and solids in industrial waste. Chemicals, such as sulfur, from burning fossil fuels. Oil and other petroleum products from supertanker spills and offshore drilling accidents. Heated water from industrial processes, such as power stations. "
which of these agricultural wastes can cause water pollution?,(A) Fertilizers (B) Animal wastes (C) Pesticides (D) All of these,D,"Huge amounts of chemicals, such as fertilizers and pesticides, are applied to farm fields (see Figure 21.10). Some of the chemicals are picked up by rainwater. Runoff then carries the chemicals to nearby rivers or lakes. Dissolved fertilizer causes too much growth of water plants and algae. This can lead to dead zones where nothing can live in lakes and at the mouths of rivers. Some of the chemicals can infiltrate into groundwater. The contaminated water comes up in water wells. If people drink the polluted water, they may get sick. Waste from livestock can also pollute water. The waste contains bacteria and other organisms that cause disease. In fact, more than 40 human diseases can be caused by water polluted with animal waste. Many farms in the U.S. have thousands of animals. These farms produce millions of gallons of waste. The waste is stored in huge lagoons, like the one in Figure 21.11. Unfortunately, many leaks from these lagoons have occurred. Two examples are described below. In North Carolina, 25 million gallons of hog manure spilled into a nearby river. The contaminated water killed "
the process that changes solid rock into sediments.,(A) Erosion (B) Weathering (C) Dissolution (D) Fracture,B,"Weathering is the process that changes solid rock into sediments. Sediments were described in the chapter ""Ma- terials of Earths Crust."" With weathering, rock is disintegrated. It breaks into pieces. Once these sediments are separated from the rocks, erosion is the process that moves the sediments. While plate tectonics forces work to build huge mountains and other landscapes, the forces of weathering gradually wear those rocks and landscapes away. Together with erosion, tall mountains turn into hills and even plains. The Appalachian Mountains along the east coast of North America were once as tall as the Himalayas. "
the process that moves sediments.,(A) Erosion (B) Weathering (C) Dissolution (D) Fracture,A,"Weathering is the process that changes solid rock into sediments. Sediments were described in the chapter ""Ma- terials of Earths Crust."" With weathering, rock is disintegrated. It breaks into pieces. Once these sediments are separated from the rocks, erosion is the process that moves the sediments. While plate tectonics forces work to build huge mountains and other landscapes, the forces of weathering gradually wear those rocks and landscapes away. Together with erosion, tall mountains turn into hills and even plains. The Appalachian Mountains along the east coast of North America were once as tall as the Himalayas. "
weathering happens rapidly; often in a matter of years or decades.,(A) True (B) False,B,"Weather makes life interesting. Weather also causes weathering. Weathering is the slow wearing down of rocks on Earths surface. Wind-blown sand scours rocks like sandpaper. Glaciers of ice scrape across rock surfaces like a file. Even gentle rain may seep into rocks and slowly dissolve them. If the water freezes, it expands. This eventually causes the rocks to crack. Without the atmosphere, none of this weathering would happen. "
the appalachians were once as tall as the himalayas and have since weathered and eroded.,(A) True (B) False,A,"Wegener found rocks of the same type and age on both sides of the Atlantic Ocean. He thought that the rocks formed side by side. These rocks then drifted apart on separate continents. Wegener also matched up mountain ranges across the Atlantic Ocean. The Appalachian Mountains were just like mountain ranges in eastern Greenland, Ireland, Great Britain, and Norway. Wegener concluded that they formed as a single mountain range. This mountain range broke apart as the continents split up. The mountain range separated as the continents drifted. "
what can cause erosion?,(A) Water (B) Wind (C) Ice (D) All of the above,D,"Even things that people do for fun can expose soil to erosion. For example, overuse of hiking trails can leave bare patches of soil. Off-road vehicles cause even more damage. You can see examples of this in Figure 19.5. "
which is an example of chemical weathering?,(A) A rock breaking into fragments (B) A rock being scratched by rocks embedded in the bottom of a glacier (C) A rock dissolving in water (D) Sediment being moved down a hillside,C,"Now that you know what chemical weathering is, can you think of some other ways chemical weathering might occur? Chemical weathering can also be contributed to by plants and animals. As plant roots take in soluble ions as nutrients, certain elements are exchanged. Plant roots and bacterial decay use carbon dioxide in the process of respiration. "
weathering and erosion can change land over time.,(A) True (B) False,A,"Weathering is the process that changes solid rock into sediments. Sediments were described in the chapter ""Ma- terials of Earths Crust."" With weathering, rock is disintegrated. It breaks into pieces. Once these sediments are separated from the rocks, erosion is the process that moves the sediments. While plate tectonics forces work to build huge mountains and other landscapes, the forces of weathering gradually wear those rocks and landscapes away. Together with erosion, tall mountains turn into hills and even plains. The Appalachian Mountains along the east coast of North America were once as tall as the Himalayas. "
"weathering can change roads, sidewalks, buildings and sculptures over time.",(A) True (B) False,A,"No human being can watch for millions of years as mountains are built, nor can anyone watch as those same mountains gradually are worn away. But imagine a new sidewalk or road. The new road is smooth and even. Over hundreds of years, it will completely disappear, but what happens over one year? What changes would you see? (Figure 1.1). What forces of weathering wear down that road, or rocks or mountains over time? A once smooth road surface has cracks and fractures, plus a large pothole. Click image to the left or use the URL below. URL: "
the gargoyles on notre dame cathedral are pitted in ways the artists never meant to happen. this is due to,(A) Chemical weathering (B) Mechanical weathering (C) Erosion (D) All of the above,A,"Human activities are responsible for enormous amounts of mechanical weathering, by digging or blasting into rock to build homes, roads, and subways, or to quarry stone. (a) Humans are tremendous agents of mechanical weathering. (b) Salt weathering of building stone on the island of Gozo, Malta. "
"if a river in flood picks up a house and moves it downstream, this is",(A) Chemical weathering (B) Mechanical weathering (C) Erosion (D) All of the above,C,"A flood occurs when so much water enters a stream or river that it overflows its banks. Flood waters from a river are shown in Figure 13.10. Like this flood, many floods are caused by very heavy rains. Floods may also occur when deep snow melts quickly in the spring. Floods are a natural part of the water cycle, but they can cause a lot of damage. Farms and homes may be lost, and people may die. In 1939, millions of people died in a flood in China. Although freshwater is needed to grow crops and just to live, too much freshwater in the same place at once can be deadly. "
"based on his polar experiences, wegener thought the continents",(A) Were joined into a single landmass that was near the North Pole (B) Could move like an icebreaking ship through ice sheets (C) Could not have been joined because glaciers would have originated in the oceans if they were (D) All of the above,B,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
"the continents were joined into a single landmass that has since broken apart, which wegener named",(A) Rhodinia (B) Gondwana (C) Panthelassa (D) Pangaea,D,"Wegener put his idea and his evidence together in his book The Origin of Continents and Oceans, first published in 1915. New editions with additional evidence were published later in the decade. In his book he said that around 300 million years ago the continents had all been joined into a single landmass he called Pangaea, meaning all earth in ancient Greek. The supercontinent later broke apart and the continents having been moving into their current positions ever since. He called his hypothesis continental drift. "
many of the best scientists of the day agreed with wegeners hypothesis even though he did not have a plausible mechanism for continental movement.,(A) True (B) False,B,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
the reason scientists did not accept wegeners mechanism for continental drift is,(A) If these forces were strong enough to move continents the planet would spin out of control (B) They calculated that centrifugal and tidal forces are too weak to move the continents (C) If the continents were plowing through ocean basins (D) sea level should be much higher than it is (E) d None of these,B,"Wegeners idea seemed so outlandish at the time that he was ridiculed by other scientists. What do you think the problem was? To his colleagues, his greatest problem was that he had no plausible mechanism for how the continents could move through the oceans. Based on his polar experiences, Wegener suggested that the continents were like icebreaking ships plowing through ice sheets. The continents moved by centrifugal and tidal forces. As Wegeners colleague, how would you go about showing whether these forces could move continents? What observations would you expect to see on these continents? Alfred Wegener suggested that continen- tal drift occurred as continents cut through the ocean floor, in the same way as this icebreaker plows through sea ice. Early hypotheses proposed that centrifu- gal forces moved continents. This is the same force that moves the swings out- ward on a spinning carnival ride. Scientists at the time calculated that centrifugal and tidal forces were too weak to move continents. When one scientist did calculations that assumed that these forces were strong enough to move continents, his result was that if Earth had such strong forces the planet would stop rotating in less than one year. In addition, scientists also thought that the continents that had been plowing through the ocean basins should be much more deformed than they are. Wegener answered his question of whether Africa and South America had once been joined. But a hypothesis is rarely accepted without a mechanism to drive it. Are you going to support Wegener? A very few scientists did, since his hypothesis elegantly explained the similar fossils and rocks on opposite sides of the ocean, but most did not. "
this drives continental movements.,(A) Convection currents in the mantle (B) Centrifugal forces (C) Tidal forces (D) Horizontal heat conduction,A,"Seafloor spreading is the mechanism for Wegeners drifting continents. Convection currents within the mantle take the continents on a conveyor-belt ride of oceanic crust that, over millions of years, takes them around the planets surface. The spreading plate takes along any continent that rides on it. Click image to the left or use the URL below. URL: "
the heat source for plate motions is the mantle.,(A) True (B) False,B,"Convection within the Earths mantle causes the plates to move. Mantle material is heated above the core. The hot mantle rises up towards the surface (Figure 6.16). As the mantle rises it cools. At the surface the material moves horizontally away from a mid-ocean ridge crest. The material continues to cool. It sinks back down into the mantle at a deep sea trench. The material sinks back down to the core. It moves horizontally again, completing a convection cell. "
a convection cell explains a circular motion of,(A) Warm material rising and cool material sinking (B) Cool material rising and warm material sinking (C) Deep material being squeezed by high pressure to the surface and surface material falling into the deep (D) Surface material becoming dense and sinking due to high pressure and deep material having less pressure and so becoming buoyant,A,"The Figure 1.1 shows how convection occurs, using hot water in a pot as an example. When particles in one area of a fluid (in this case, the water at the bottom of the pot) gain thermal energy, they move more quickly, have more collisions, and spread farther apart. This decreases the density of the particles, so they rise up through the fluid. As they rise, they transfer their thermal energy to other particles of the fluid and cool off in the process. With less energy, the particles move more slowly, have fewer collisions, and move closer together. This increases their density, so they sink back down through the fluid. When they reach the bottom of the fluid, the cycle repeats. The result is a loop of moving particles called a convection current. "
scientists rejected wegeners theory because,(A) It didn’t explain the fossil evidence (B) It didn’t explain the puzzle-like fit of the continents (C) There was no plausible mechanism to explain continental movement (D) All of the above,C,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
"where two adjacent convection cells rise to the surface, a continent could break apart and the pieces could move in the opposite direction.",(A) True (B) False,A,"Wegener had many thoughts regarding what could be the driving force behind continental drift. Another of We- geners colleagues, Arthur Holmes, elaborated on Wegeners idea that there is thermal convection in the mantle. In a convection cell, material deep beneath the surface is heated so that its density is lowered and it rises. Near the surface it becomes cooler and denser, so it sinks. Holmes thought this could be like a conveyor belt. Where two adjacent convection cells rise to the surface, a continent could break apart with pieces moving in opposite directions. Although this sounds like a great idea, there was no real evidence for it, either. Alfred Wegener died in 1930 on an expedition on the Greenland icecap. For the most part the continental drift idea was put to rest for a few decades, until technological advances presented even more evidence that the continents moved and gave scientists the tools to develop a mechanism for Wegeners drifting continents. Since youre on a virtual field trip, you get to go along with them as well. Click image to the left or use the URL below. URL: "
the hypothesis of continental drift was ignored until new evidence was found that pointed to a mechanism.,(A) True (B) False,A,Wegener and his supporters collected a great deal of evidence for the continental drift hypothesis. Wegener found that this evidence was best explained if the continents had at one time been joined together. 
waves break when they become too tall to be supported by their base.,(A) True (B) False,A,"When does a wave break? Do waves only break when they reach shore? Waves break when they become too tall to be supported by their base. This can happen at sea but happens predictably as a wave moves up a shore. The energy at the bottom of the wave is lost by friction with the ground, so that the bottom of the wave slows down but the top of the wave continues at the same speed. The crest falls over and crashes down. "
water that is pushed in a pile near shore by storm winds causing sea levels to rise locally.,(A) Massive Wave (B) Flood (C) Storm Surge (D) None of the above,C,"Some of the damage done by storms is from storm surge. Water piles up at a shoreline as storm winds push waves into the coast. Storm surge may raise sea level as much as 7.5 m (25 ft), which can be devastating in a shallow land area when winds, waves, and rain are intense. Maverick waves are massive. Learning how they are generated can tell scientists a great deal about how the ocean creates waves and especially large waves. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
waves get started when,(A) Wind energy creates tiny ripples that are easier for later winds to catch onto (B) Wind gusts fast across a flat sea (C) A high pressure cell pushes down on the sea surface so that when it bounces back it starts waves (D) None of these,A,"When does a wave break? Do waves only break when they reach shore? Waves break when they become too tall to be supported by their base. This can happen at sea but happens predictably as a wave moves up a shore. The energy at the bottom of the wave is lost by friction with the ground, so that the bottom of the wave slows down but the top of the wave continues at the same speed. The crest falls over and crashes down. "
"in deep water, water molecules travel in a ________________ motion.",(A) Back-and-forth (B) Up and down (C) Random (D) Circular,D,"Water molecules in waves make circles or ellipses (Figure 1.1). Energy transfers between molecules, but the molecules themselves mostly bob up and down in place. The circles show the motion of a water molecule in a wind wave. Wave energy is greatest at the surface and decreases with depth. ""A"" shows that a water molecule travels in a circular motion in deep water. ""B"" shows that molecules in shallow water travel in an elliptical path because of the ocean bottom. "
wave energy is lowest at the surface and increases with depth.,(A) True (B) False,B,"Water molecules in waves make circles or ellipses (Figure 1.1). Energy transfers between molecules, but the molecules themselves mostly bob up and down in place. The circles show the motion of a water molecule in a wind wave. Wave energy is greatest at the surface and decreases with depth. ""A"" shows that a water molecule travels in a circular motion in deep water. ""B"" shows that molecules in shallow water travel in an elliptical path because of the ocean bottom. "
the energy contained in bottom of the wave is reduced due to friction with the shore.,(A) True (B) False,A,"In deep water, particles of water just move in circles. They dont actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. Look at the Figure 1.2. You can see how the waves start to drag on the bottom in shallow water. This creates friction that slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. The difference in speed causes the waves to get steeper until they topple over and break. The crashing waves carry water onto the shore as surf. Q: In this diagram of a wave breaking near shore, where do you think a surfer would try to catch the wave? A: The surfer would try to catch the wave where it starts to steepen and lean forward toward the shore. "
the largest waves are built by,(A) Very strong winds (B) Winds that blow steadily for a long period of time (C) Winds that blow over a long distance (D) All of these,D,"Ocean waves originate from wind blowing - steady winds or high storm winds - over the water. Sometimes these winds are far from where the ocean waves are seen. What factors create the largest ocean waves? The largest wind waves form when the wind is very strong blows steadily for a long time blows over a long distance The wind could be strong, but if it gusts for just a short time, large waves wont form. Wind blowing across the water transfers energy to that water. The energy first creates tiny ripples, which make an uneven surface for the wind to catch so that it may create larger waves. These waves travel across the ocean out of the area where the wind is blowing. Remember that a wave is a transfer of energy. Do you think the same molecules of water that start out in a wave in the middle of the ocean later arrive at the shore? The molecules are not the same, but the energy is transferred across the ocean. "
the water in a wave travels across the ocean to end up on a shoreline.,(A) True (B) False,B,"Figure 14.10 shows what happens to waves near shore. As waves move into shallow water, they start to touch the bottom. The base of the waves drag and slow. Soon the waves slow down and pile up. They get steeper and unstable as the top moves faster than the base. When they reach the shore, the waves topple over and break. "
why does a bottle appear to bob in place when its in a lake with small waves?,(A) The bottle experiences just up and down motion (B) The bottle is moving in a circle (C) but staying roughly in place (D) c The bottle appears to stay in place (E) but it is actually moving slowly forward (F) d None of these,B,"Water molecules in waves make circles or ellipses (Figure 1.1). Energy transfers between molecules, but the molecules themselves mostly bob up and down in place. The circles show the motion of a water molecule in a wind wave. Wave energy is greatest at the surface and decreases with depth. ""A"" shows that a water molecule travels in a circular motion in deep water. ""B"" shows that molecules in shallow water travel in an elliptical path because of the ocean bottom. "
Who invented the microscope?,(A) Robert Hooke (B) Anton van Leeuwenhoek (C) Zacharias and Hans Jansen (D) none of the above,C,"The microscope was invented more than four centuries ago. In the late 1500s, two Dutch eyeglass makers, Zacharias Jansen and his father Hans, built the first microscope. They put several magnifying lenses in a tube. They discovered that using more than one lens magnified objects more than a single lens. Their simple microscope could make small objects appear nine times bigger than they really were. "
__________The microscope was invented in the late 1800s.,(A) true (B) false,B,"The microscope was invented more than four centuries ago. In the late 1500s, two Dutch eyeglass makers, Zacharias Jansen and his father Hans, built the first microscope. They put several magnifying lenses in a tube. They discovered that using more than one lens magnified objects more than a single lens. Their simple microscope could make small objects appear nine times bigger than they really were. "
__________The earliest microscopes were light microscopes.,(A) true (B) false,A,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
What is Micrographia?,(A) a book published by van Leeuwenhoek (B) the first book of microscopic studies (C) a method of drawing microscopic images (D) two of the above,B,"In the mid-1600s, the English scientist Robert Hooke was one of the first scientists to observe living things with a microscope. He published the first book of microscopic studies, called Micrographia. It includes wonderful drawings of microscopic organisms and other objects. One of Hookes most important discoveries came when he viewed thin slices of cork under a microscope. Cork is made from the bark of a tree. When Hooke viewed it under a microscope, he saw many tiny compartments that he called cells. He made the drawing in Figure 1.11 to show what he observed. Hooke was the first person to observe the cells from a once-living organism. "
"To be seen with a light microscope, an object must be wider than 550",(A) micrometers (B) nanometers (C) millimeters (D) centimeters,B,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
__________An individual bacterial cell is invisible without a microscope.,(A) true (B) false,A,"Many life science discoveries would not have been possible without the microscope. For example: Cells are the tiny building blocks of living things. They couldnt be discovered until the microscope was invented. The discovery of cells led to the cell theory. This is one of the most important theories in life science. Bacteria are among the most numerous living things on the planet. They also cause many diseases. However, no one knew bacteria even existed until they could be seen with a microscope. The invention of the microscope allowed scientists to see cells, bacteria, and many other structures that are too small to be seen with the unaided eye. It gave them a direct view into the unseen world of the extremely tiny. You can get a glimpse of that world in Figure 1.10. "
__________Many life science discoveries would not have been possible without the microscope.,(A) true (B) false,A,"Many life science discoveries would not have been possible without the microscope. For example: Cells are the tiny building blocks of living things. They couldnt be discovered until the microscope was invented. The discovery of cells led to the cell theory. This is one of the most important theories in life science. Bacteria are among the most numerous living things on the planet. They also cause many diseases. However, no one knew bacteria even existed until they could be seen with a microscope. The invention of the microscope allowed scientists to see cells, bacteria, and many other structures that are too small to be seen with the unaided eye. It gave them a direct view into the unseen world of the extremely tiny. You can get a glimpse of that world in Figure 1.10. "
Electron microscopes can make clear images that are as much as two,(A) hundred times bigger than the actual object (B) thousand times bigger than the actual object (C) million times bigger than the actual object (D) billion times bigger than the actual object,C,"Some modern microscopes use light, as Hookes and van Leeuwenhoeks did. Others may use electron beams or sound waves. Researchers now use these four types of microscopes: 1. Light microscopes allow biologists to see small details of a specimen. Most of the microscopes used in schools and laboratories are light microscopes. Light microscopes use lenses, typically made of glass or plastic, to focus light either into the eye, a camera, or some other light detector. The most powerful light microscopes can make images up to 2,000 times larger. 2. Transmission electron microscopes (TEM) focus a beam of electrons through an object and can make an image up to two million times bigger, with a very clear image. 3. Scanning electron microscopes (SEM) allow scientists to find the shape and surface texture of extremely small objects, including a paperclip, a bedbug, or even an atom. These microscopes slide a beam of electrons across the surface of a specimen, producing detailed maps of the surface of objects. Magnification in a SEM can be controlled over a range from about 10 to 500,000 times. 4. Scanning acoustic microscopes use sound waves to scan a specimen. These microscopes are useful in biology and medical research. "
__________An electron microscope magnifies objects up to 2 billion times larger than their actual size.,(A) true (B) false,B,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
The tiny building blocks of organisms are called,(A) bacteria (B) microorganisms (C) animalcules (D) cells,D,"Cells are the basic building blocks of life. They are like tiny factories where virtually all life processes take place. Some living things, like the bacteria in Figure 2.1, consist of just one cell. They are called single-celled organisms. You can see other single-celled organisms in Figure 2.2. Some living things are composed of a few to many trillions of cells. They are called multicellular organisms. Your body is composed of trillions of cells. Regardless of the type of organism, all living cells share certain basic structures. For example, all cells are enclosed by a membrane. The cell membrane separates the cell from its environment. It also controls what enters or leaves the cell. "
__________The first microscope was made by Anton van Leeuwenhoek.,(A) true (B) false,B,"In the late 1600s, Anton van Leeuwenhoek, a Dutch lens maker and scientist, started making much stronger microscopes. His microscopes could magnify objects as much as 270 times their actual size. Van Leeuwenhoek made many scientific discoveries using his microscopes. He was the first to see and describe bacteria. He observed them in a sample of plaque that he had scraped off his own teeth. He also saw yeast cells, human sperm cells, and the microscopic life teeming in a drop of pond water. He even saw blood cells circulating in tiny blood vessels called capillaries. The drawings in Figure 1.12 show some of tiny organisms and living cells that van Leeuwenhoek viewed with his microscopes. He called them animalcules. "
__________The Jansens discovered that one lens magnified objects more than several lenses.,(A) true (B) false,B,"The microscope was invented more than four centuries ago. In the late 1500s, two Dutch eyeglass makers, Zacharias Jansen and his father Hans, built the first microscope. They put several magnifying lenses in a tube. They discovered that using more than one lens magnified objects more than a single lens. Their simple microscope could make small objects appear nine times bigger than they really were. "
_The cell theory depended on the discovery of the microscope.,(A) true (B) false,A,"Many life science discoveries would not have been possible without the microscope. For example: Cells are the tiny building blocks of living things. They couldnt be discovered until the microscope was invented. The discovery of cells led to the cell theory. This is one of the most important theories in life science. Bacteria are among the most numerous living things on the planet. They also cause many diseases. However, no one knew bacteria even existed until they could be seen with a microscope. The invention of the microscope allowed scientists to see cells, bacteria, and many other structures that are too small to be seen with the unaided eye. It gave them a direct view into the unseen world of the extremely tiny. You can get a glimpse of that world in Figure 1.10. "
_Only light of certain wavelengths is visible to the human eye.,(A) true (B) false,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
_The Jansens microscopes were stronger than van Leeuwenhoeks microscopes.,(A) true (B) false,B,"In the late 1600s, Anton van Leeuwenhoek, a Dutch lens maker and scientist, started making much stronger microscopes. His microscopes could magnify objects as much as 270 times their actual size. Van Leeuwenhoek made many scientific discoveries using his microscopes. He was the first to see and describe bacteria. He observed them in a sample of plaque that he had scraped off his own teeth. He also saw yeast cells, human sperm cells, and the microscopic life teeming in a drop of pond water. He even saw blood cells circulating in tiny blood vessels called capillaries. The drawings in Figure 1.12 show some of tiny organisms and living cells that van Leeuwenhoek viewed with his microscopes. He called them animalcules. "
_Electron microscopes are more powerful than light microscopes.,(A) true (B) false,A,"Some modern microscopes use light, as Hookes and van Leeuwenhoeks did. Others may use electron beams or sound waves. Researchers now use these four types of microscopes: 1. Light microscopes allow biologists to see small details of a specimen. Most of the microscopes used in schools and laboratories are light microscopes. Light microscopes use lenses, typically made of glass or plastic, to focus light either into the eye, a camera, or some other light detector. The most powerful light microscopes can make images up to 2,000 times larger. 2. Transmission electron microscopes (TEM) focus a beam of electrons through an object and can make an image up to two million times bigger, with a very clear image. 3. Scanning electron microscopes (SEM) allow scientists to find the shape and surface texture of extremely small objects, including a paperclip, a bedbug, or even an atom. These microscopes slide a beam of electrons across the surface of a specimen, producing detailed maps of the surface of objects. Magnification in a SEM can be controlled over a range from about 10 to 500,000 times. 4. Scanning acoustic microscopes use sound waves to scan a specimen. These microscopes are useful in biology and medical research. "
_Light microscopes are no longer used today.,(A) true (B) false,B,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
__________first scientist to observe bacteria with a microscope,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,B,"In the late 1600s, Anton van Leeuwenhoek, a Dutch lens maker and scientist, started making much stronger microscopes. His microscopes could magnify objects as much as 270 times their actual size. Van Leeuwenhoek made many scientific discoveries using his microscopes. He was the first to see and describe bacteria. He observed them in a sample of plaque that he had scraped off his own teeth. He also saw yeast cells, human sperm cells, and the microscopic life teeming in a drop of pond water. He even saw blood cells circulating in tiny blood vessels called capillaries. The drawings in Figure 1.12 show some of tiny organisms and living cells that van Leeuwenhoek viewed with his microscopes. He called them animalcules. "
__________microscopic building block of all living things,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,C,"Cells are the basic building blocks of life. They are like tiny factories where virtually all life processes take place. Some living things, like the bacteria in Figure 2.1, consist of just one cell. They are called single-celled organisms. You can see other single-celled organisms in Figure 2.2. Some living things are composed of a few to many trillions of cells. They are called multicellular organisms. Your body is composed of trillions of cells. Regardless of the type of organism, all living cells share certain basic structures. For example, all cells are enclosed by a membrane. The cell membrane separates the cell from its environment. It also controls what enters or leaves the cell. "
__________scientist who discovered cells,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,F,"British scientist Robert Hooke first discovered cells in 1665. He was one of the earliest scientists to study living things under a microscope. He saw that cork was divided into many tiny compartments, like little rooms. (Do the cells in Figure 3.1 look like little rooms to you too?) Hooke called these little rooms cells. Cork comes from trees, so what Hooke observed was dead plant cells. In the late 1600s, Dutch scientist Anton van Leeuwenhoek made more powerful microscopes. He used them to observe cells of other organisms. For example, he saw human blood cells and bacterial cells. Over the next century, microscopes were improved and more cells were observed. "
__________type of microscope that uses lenses to refract visible light,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,G,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
__________general term for an instrument that makes magnified images of very small objects,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,A,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or more eyepiece lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! For more on light microscopes and the images they create, watch the video at this URL:  (7:29). MEDIA Click image to the left or use the URL below. URL: "
__________name associated with the invention of the microscope,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,D,"Over four hundred years ago, two Dutch spectacle makers, Zaccharias Janssen and his son Hans, were experimenting with several lenses in a tube. They discovered that nearby objects appeared greatly enlarged, or magnified. This was the forerunner of the compound microscope and of the telescope. In 1665, Robert Hooke, an English natural scientist, used a microscope to zoom in on a piece of cork - the stuff that makes up the stoppers in wine bottles, which is made from tree bark. Inside of cork, he discovered tiny structures, which he called cells. It turns out that cells are the smallest structural unit of living organisms. This finding eventually led to the development of the theory that all living things are made of cells. Without microscopes, this discovery would not have been possible, and the cell theory would not have been developed. Hookes discovery of the cell set the stage for other scientists to discover other types of organisms. After Hooke, the ""father of microscopy,"" Dutch scientist Antoine van Leeuwenhoek ( Figure 1.2) taught himself to make one of the first microscopes. In one of his early experiments, van Leeuwenhoek took a sample of scum from his own teeth and used his microscope to discover bacteria, the smallest living organism on the planet. Using microscopes, van Leeuwenhoek also discovered one-celled protists and sperm cells. Today, microscopes are used by all types of scientists, including cell biologists, microbiologists, virologists, forensic scientists, entomologists, taxonomists, and many other types. Antoine van Leeuwenhoek, a Dutch cloth merchant with a passion for microscopy. "
__________type of microscope that passes electrons over or through objects,(A) amicroscope (B) bvan Leeuwenhoek (C) ccell (D) dJansen (E) eelectron microscope (F) fHooke (G) glight microscope,E,"Some modern microscopes use light, as Hookes and van Leeuwenhoeks did. Others may use electron beams or sound waves. Researchers now use these four types of microscopes: 1. Light microscopes allow biologists to see small details of a specimen. Most of the microscopes used in schools and laboratories are light microscopes. Light microscopes use lenses, typically made of glass or plastic, to focus light either into the eye, a camera, or some other light detector. The most powerful light microscopes can make images up to 2,000 times larger. 2. Transmission electron microscopes (TEM) focus a beam of electrons through an object and can make an image up to two million times bigger, with a very clear image. 3. Scanning electron microscopes (SEM) allow scientists to find the shape and surface texture of extremely small objects, including a paperclip, a bedbug, or even an atom. These microscopes slide a beam of electrons across the surface of a specimen, producing detailed maps of the surface of objects. Magnification in a SEM can be controlled over a range from about 10 to 500,000 times. 4. Scanning acoustic microscopes use sound waves to scan a specimen. These microscopes are useful in biology and medical research. "
The invention of the microscope allowed scientists to see,(A) cells (B) bacteria (C) human sperm (D) all of the above,D,"Many life science discoveries would not have been possible without the microscope. For example: Cells are the tiny building blocks of living things. They couldnt be discovered until the microscope was invented. The discovery of cells led to the cell theory. This is one of the most important theories in life science. Bacteria are among the most numerous living things on the planet. They also cause many diseases. However, no one knew bacteria even existed until they could be seen with a microscope. The invention of the microscope allowed scientists to see cells, bacteria, and many other structures that are too small to be seen with the unaided eye. It gave them a direct view into the unseen world of the extremely tiny. You can get a glimpse of that world in Figure 1.10. "
A microscope is an instrument that makes,(A) tiny objects look bigger (B) distant objects look closer (C) distant objects look bigger (D) large objects look smaller,A,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one shown in the Figure lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! Q: How has the microscope advanced scientific knowledge? A: The microscope has revealed secrets of the natural world like no other single invention. The microscope let scientists see entire new worlds, leading to many discoveriesespecially in biology and medicinethat could not have been made without it. Some examples include the discovery of cells and the identification of bacteria and other single-celled organisms. With the development of more powerful microscopes, viruses were discovered and even atoms finally became visible. These discoveries changed our ideas about the human body and the nature of life itself. "
The inventors of the microscope were,(A) English (B) Dutch (C) German (D) American,B,"Over four hundred years ago, two Dutch spectacle makers, Zaccharias Janssen and his son Hans, were experimenting with several lenses in a tube. They discovered that nearby objects appeared greatly enlarged, or magnified. This was the forerunner of the compound microscope and of the telescope. In 1665, Robert Hooke, an English natural scientist, used a microscope to zoom in on a piece of cork - the stuff that makes up the stoppers in wine bottles, which is made from tree bark. Inside of cork, he discovered tiny structures, which he called cells. It turns out that cells are the smallest structural unit of living organisms. This finding eventually led to the development of the theory that all living things are made of cells. Without microscopes, this discovery would not have been possible, and the cell theory would not have been developed. Hookes discovery of the cell set the stage for other scientists to discover other types of organisms. After Hooke, the ""father of microscopy,"" Dutch scientist Antoine van Leeuwenhoek ( Figure 1.2) taught himself to make one of the first microscopes. In one of his early experiments, van Leeuwenhoek took a sample of scum from his own teeth and used his microscope to discover bacteria, the smallest living organism on the planet. Using microscopes, van Leeuwenhoek also discovered one-celled protists and sperm cells. Today, microscopes are used by all types of scientists, including cell biologists, microbiologists, virologists, forensic scientists, entomologists, taxonomists, and many other types. Antoine van Leeuwenhoek, a Dutch cloth merchant with a passion for microscopy. "
Van Leeuwenhoeks microscopes could magnify objects as much as,(A) 270 times their actual size (B) 550 times their actual size (C) 1 (D) 000 times their actual size (E) d none of the above,A,"In the late 1600s, Anton van Leeuwenhoek, a Dutch lens maker and scientist, started making much stronger microscopes. His microscopes could magnify objects as much as 270 times their actual size. Van Leeuwenhoek made many scientific discoveries using his microscopes. He was the first to see and describe bacteria. He observed them in a sample of plaque that he had scraped off his own teeth. He also saw yeast cells, human sperm cells, and the microscopic life teeming in a drop of pond water. He even saw blood cells circulating in tiny blood vessels called capillaries. The drawings in Figure 1.12 show some of tiny organisms and living cells that van Leeuwenhoek viewed with his microscopes. He called them animalcules. "
Light microscopes refract visible light and form images with,(A) electrons (B) lenses (C) slides (D) bulbs,B,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
What is the magnification of the most powerful light microscope?,(A) 20 times (B) 200 times (C) 2 (D) 000 times (E) d 2 (F) 000 (G) 000 times,C,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
The wavelength of visible light is,(A) 5 nanometers (B) 55 nanometers (C) 550 nanometers (D) 5 (E) 500 nanometers,C,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
Which statement is true about both flatworms and roundworms?,(A) They lack body symmetry (B) They may be parasites (C) They have a complete digestive system (D) all of the above,B,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
How many species belong to Phylum Platyhelminthes?,(A) more than 25 (B) 000 (C) b fewer than 15 (D) 000 (E) c about 10 (F) 000 (G) d about 8 (H) 000,A,"Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. "
Flatworms are flat because they,(A) have an incomplete digestive system (B) lack a pseudocoelom or coelom (C) have just two embryonic cell layers (D) lack a mesoderm cell layer,B,"Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: "
All flatworms,(A) are less than a meter long (B) live in water or moist soil (C) reproduce asexually by budding (D) have a concentration of nerve tissue in the head end,D,"Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. "
Which of the following organisms is a flatworm?,(A) hookworm (B) ascaris (C) tapeworm (D) all of the above,C,"Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. "
Flatworms reproduce by producing,(A) buds (B) spores (C) gametes (D) none of the above,C,"Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. "
Both flatworms and roundworms may be found living in,(A) water (B) moist soil (C) vertebrate hosts (D) any of the above,D,"Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. "
The body of a roundworm is covered with,(A) slime (B) hooks (C) suckers (D) cuticle,D,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
Which statement about roundworm reproduction is true?,(A) Sperm and eggs are produced by the same adult (B) Fertilization occurs in the water outside the adults body (C) Eggs hatch into larvae (D) which develop into adults (E) d Reproduction may occur sexually or asexually,C,"Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. "
A roundworms body is stiff because of,(A) the endoskeleton (B) the exoskeleton (C) fluid pressure (D) a notochord,C,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
Free-living roundworms may feed on,(A) bacteria (B) fungi (C) protists (D) all of the above,D,"Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video:  . MEDIA Click image to the left or use the URL below. URL: "
How many eggs can a single roundworm lay in a day?,(A) about 10 (B) up to 100 (C) around 1 (D) 000 (E) d as many as 100 (F) 000,D,"Roundworms reproduce sexually. Sperm and eggs are produced by separate male and female adults. Fertilization takes place inside the female organism. Females lay huge numbers of eggs, sometimes as many as 100,000 per day! The eggs hatch into larvae, which develop into adults. Then the life cycle repeats. "
Most flatworm species have separate sexes.,(A) true (B) false,B,"Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. "
"When flatworms reproduce, eggs are fertilized outside the body.",(A) true (B) false,B,"Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. "
"Flatworms can eat, digest food, and eliminate wastes all at the same time.",(A) true (B) false,B,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
"Free-living roundworms may feed on bacteria, fungi, or protozoa.",(A) true (B) false,A,"Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video:  . MEDIA Click image to the left or use the URL below. URL: "
Roundworms play an important role in the carbon cycle.,(A) true (B) false,A,"Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video:  . MEDIA Click image to the left or use the URL below. URL: "
_All flatworms are several meters long.,(A) true (B) false,B,"Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. "
_Flatworms have a concentration of nerve tissue in the head end.,(A) true (B) false,A,"Flatworms have a flat body because they lack a fluid-filled body cavity. They also have an incomplete digestive system with a single opening. However, flatworms represent several evolutionary advances in invertebrates. They have the following adaptations: Flatworms have three embryonic cell layers. They have a mesoderm layer in addition to ectoderm and endoderm layers. The mesoderm layer allows flatworms to develop muscle tissues so they can move easily over solid surfaces. Flatworms have a concentration of nerve tissue in the head end. This was a major step in the evolution of a brain. It was also needed for bilateral symmetry. Flatworms have bilateral symmetry. This gives them a better sense of direction than radial symmetry would. Watch this amazing flatworm video to learn about some of the other firsts these simple animals achieved, including being the first hunters: http://shapeoflife.org/video/flatworms-first-hunter MEDIA Click image to the left or use the URL below. URL: "
_Flatworms may have several different larval stages.,(A) true (B) false,A,"Flatworms reproduce sexually. In most species, the same individuals produce both eggs and sperm. After fertilization occurs, the fertilized eggs pass out of the adults body and hatch into larvae. There may be several different larval stages. The final larval stage develops into the adult form. Then the life cycle repeats. "
_A parasitic flatworm usually needs more than one type of host to complete its life cycle.,(A) true (B) false,A,"Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. "
_Phylum Nematoda has less than 800 known species.,(A) true (B) false,B,"Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. "
_The body of a roundworm has a tough covering of cuticle.,(A) true (B) false,A,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
_All parasitic roundworms have vertebrate hosts.,(A) true (B) false,B,"Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video:  . MEDIA Click image to the left or use the URL below. URL: "
___name of the phylum to which roundworms belong,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,C,"Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. "
___common name for the type of worm that has a pseudocoelom,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,D,The following table compares the three worm phyla (Table 1.1). Phylum Platyhelminthes Nematoda Annelida Common Name Flatworm Roundworm Segmented worm Body Cavity Segmented No Yes Yes No No Yes Digestive System Incomplete Complete Complete 
___parasitic roundworm with special structures for attaching to the hosts intestines,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,A,"Roundworms may be free-living or parasitic organisms. Free-living worms are found mainly in freshwater habitats. Some live in moist soil. They generally feed on bacteria, fungi, protozoa, or decaying organic matter. By breaking down organic matter, they play an important role in the carbon cycle. Parasitic roundworms may have plant, invertebrate, or vertebrate hosts. Several roundworm species infect humans. Besides ascaris, they include hookworms. Hookworms are named for the hooks they use to grab onto the hosts intestines. You can see the hooks in Figure 12.14. Hookworm larvae enter the host through the skin. They migrate to the intestine, where they mature into adults. Female adults lay large quantities of eggs. Eggs pass out of the host in feces. Eggs hatch into larvae in the feces or soil. Then the cycle repeats. You can learn more about parasitic roundworms in humans by watching this short video:  . MEDIA Click image to the left or use the URL below. URL: "
___common name for the type of worm that lacks a pseudocoelom,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,B,"The word ""worm"" is not very scientific. This informal term describes animals (usually invertebrates) that have long bodies with no arms or legs. Worms with round, non-segmented bodies are known as nematodes or roundworms ( Figure 1.1). They are classified in the phylum Nematoda, which has over 28,000 known species. Some scientists believe there could be over a million species of Nematodes. Nematodes are slender bilaterally symmetrical worms, typically less than 2.5 mm long. The smallest nematodes are microscopic, while free-living species can reach as much as 5 cm, and some parasitic species are larger still, reaching over a meter in length. The worm body is often covered with ridges, rings, bristles, or other distinctive structures. The radially symmetrical head of a nematode also has distinct features. The head is covered with sensory bristles and, in many cases, solid ""head-shields"" around the mouth region. The mouth has either three or six lips arranged around the mouth opening, which often have a series of teeth on their inner edges. Nematodes can be parasites of plants and animals. "
___example of a flatworm that is a human parasite,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,G,"Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. "
___name of the phylum to which flatworms belong,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,F,"Flatworms are invertebrates that belong to Phylum Platyhelminthes. There are more than 25,000 species in the flatworm phylum. Not all flatworms are as long as tapeworms. Some are only about a millimeter in length. "
___largest and most common parasitic worm in humans,(A) ahookworm (B) bflatworm (C) cNematoda (D) droundworm (E) eascaris (F) fPlatyhelminthes (G) gtapeworm,E,"Roundworms can be free-living organisms, but they are probably best known for their role as significant plant and animal parasites. Most Nematodes are parasitic, with over 16,000 parasitic species described. Heartworms, which cause serious disease in dogs while living in the heart and blood vessels, are a type of roundworm. Roundworms can also cause disease in humans. Elephantiasis, a disease characterized by the extreme swelling of the limbs ( Figure Most parasitic roundworm eggs or larvae are found in the soil and enter the human body when a person picks them up on the hands and then transfers them to the mouth. The eggs or larvae also can enter the human body directly through the skin. The best solution to these diseases is to try to prevent these diseases rather than treat or cure them. Diseases caused by roundworms are more common in developing countries. Many parasitic diseases caused by roundworms result from poor personal hygiene. Contributing factors may include lack of a clean water supply, inadequate sanitation measures, crowded living conditions, combined with a lack of access to health care and low levels of education. "
All of the following are annelids except,(A) slugs (B) earthworms (C) polychaete worms (D) leeches,A,"Annelids are divided into many repeating segments. The earthworm in Figure 12.18 is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be specialized to carry out particular functions. They may have special structures on them. For example, they might have tentacles for sensing or feeding, paddles for swimming, or suckers for clinging to surfaces. "
___special tissue on the outer surface of a mollusk that secretes a shell,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,G,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
___type of annelid that feeds off the blood of a vertebrate host,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,F,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
Organ systems found in mollusks include a(n),(A) circulatory system (B) excretory system (C) incomplete digestive system (D) two of the above,D,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
Mollusks generally have all of the following except for,(A) a head region (B) a muscular foot (C) a layer called the mantle (D) repeating body segments,D,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
___mollusk feeding organ with teeth,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,E,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
___name of the phylum to which snails belong,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,D,"Have you ever been to the ocean or eaten seafood? If you have, then youve probably encountered members of Phylum Mollusca. In addition to snails, mollusks include squids, slugs, scallops, and clams. You can see a clam in Figure 12.15. There are more than 100,000 known species of mollusks. Some mollusks are nearly microscopic. The largest mollusk, the colossal squid, may be as long as a school bus and weigh over half a ton! Watch this short video to see an amazing diversity of mollusks:  . MEDIA Click image to the left or use the URL below. URL: "
Which of the following is not an annelid structure?,(A) brain (B) sensory organs (C) large coelom (D) shell,D,"Annelids are divided into many repeating segments. The earthworm in Figure 12.18 is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be specialized to carry out particular functions. They may have special structures on them. For example, they might have tentacles for sensing or feeding, paddles for swimming, or suckers for clinging to surfaces. "
___type of annelid that lives on the ocean floor,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,C,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
What are leeches?,(A) segmented worms (B) mollusks (C) shelled invertebrates (D) two of the above,A,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
___name of the phylum to which earthworms belong,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,A,"When you think of worms, you probably picture earthworms. There are actually many types of worms, including flatworms, roundworms, and segmented worms. Earthworms are segmented worms. Segmented worms are in the phylum Annelida, which has over 22,000 known species. These worms are known as the segmented worms because their bodies are segmented, or separated into repeating units. Besides the earthworm, the segmented worms also include leeches and some marine worms. Most segmented worms like the earthworm, feed on dead organic matter. Leeches (Figure 1.1), however, can live in fresh water and suck blood from their animal host. You may have noticed many earthworms in soil. Earthworms support terrestrial ecosystems both as prey and by aerating and enriching soil. "
___trait found in annelids but not in roundworms,(A) aAnnelida (B) bsegmentation (C) cpolychaete worm (D) dMollusca (E) eradula (F) fleech (G) gmantle,B,"Annelids are divided into many repeating segments. The earthworm in Figure 12.18 is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be specialized to carry out particular functions. They may have special structures on them. For example, they might have tentacles for sensing or feeding, paddles for swimming, or suckers for clinging to surfaces. "
Some mollusks are so small that they are nearly microscopic.,(A) true (B) false,A,"Have you ever been to the ocean or eaten seafood? If you have, then youve probably encountered members of Phylum Mollusca. In addition to snails, mollusks include squids, slugs, scallops, and clams. You can see a clam in Figure 12.15. There are more than 100,000 known species of mollusks. Some mollusks are nearly microscopic. The largest mollusk, the colossal squid, may be as long as a school bus and weigh over half a ton! Watch this short video to see an amazing diversity of mollusks:  . MEDIA Click image to the left or use the URL below. URL: "
The head of a mollusk may have tentacles for sensing the environment.,(A) true (B) false,A,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
All mollusks are free-living heterotrophs.,(A) true (B) false,B,"Mollusks live in most terrestrial, freshwater, and marine habitats. However, the majority of species live in the ocean. They can be found in both shallow and deep water and from tropical to polar latitudes. They have a variety of ways of getting food. Some are free-living heterotrophs. Others are internal parasites. Mollusks are also eaten by many other organisms, including humans. "
There are more than a million known species of annelids.,(A) true (B) false,B,"Annelids are segmented worms in Phylum Annelida. There are about 15,000 species of annelids. They range in length from less than a millimeter to more than 3 meters. To learn more about the amazing diversity and adaptations of annelids, watch this excellent video: http://shapeoflife.org/video/annelids-powerful-and-capable-worms MEDIA Click image to the left or use the URL below. URL: "
Annelids can reproduce only sexually.,(A) true (B) false,B,Most annelids can reproduce both asexually and sexually. Asexual reproduction may occur by budding or fission. Sexual reproduction varies by species. Some species go through a larval stage before developing into adults. Other species grow to adult size without going through a larval stage. 
"_There are more than 100,000 known species of mollusks.",(A) true (B) false,A,"There are approximately 160,000 living species and probably 70,000 extinct species of mollusks. They are typically divided into ten classes, of which two are extinct. The major classes of living mollusks include gastropods, bivalves, and cephalopods ( Figure 1.1). "
_The largest mollusk is about as big as a human adults fist.,(A) true (B) false,B,"Have you ever been to the ocean or eaten seafood? If you have, then youve probably encountered members of Phylum Mollusca. In addition to snails, mollusks include squids, slugs, scallops, and clams. You can see a clam in Figure 12.15. There are more than 100,000 known species of mollusks. Some mollusks are nearly microscopic. The largest mollusk, the colossal squid, may be as long as a school bus and weigh over half a ton! Watch this short video to see an amazing diversity of mollusks:  . MEDIA Click image to the left or use the URL below. URL: "
_A mollusk has a heart that pumps blood.,(A) true (B) false,A,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
_The majority of mollusks live in moist soil.,(A) true (B) false,B,"Mollusks live in most terrestrial, freshwater, and marine habitats. However, the majority of species live in the ocean. They can be found in both shallow and deep water and from tropical to polar latitudes. They have a variety of ways of getting food. Some are free-living heterotrophs. Others are internal parasites. Mollusks are also eaten by many other organisms, including humans. "
_Annelids may have tentacles that they use for sensing or feeding.,(A) true (B) false,A,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
_Annelids have a large coelom.,(A) true (B) false,A,"Annelids have a large coelom. They also have several organ systems. These include a: circulatory system; excretory system; complete digestive system; and nervous system, with a brain and sensory organs. "
_Some annelids are filter feeders.,(A) true (B) false,A,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
Mollusks include,(A) slugs (B) squids (C) scallops (D) all of the above,D,"Have you ever been to the ocean or eaten seafood? If you have, then youve probably encountered members of Phylum Mollusca. In addition to snails, mollusks include squids, slugs, scallops, and clams. You can see a clam in Figure 12.15. There are more than 100,000 known species of mollusks. Some mollusks are nearly microscopic. The largest mollusk, the colossal squid, may be as long as a school bus and weigh over half a ton! Watch this short video to see an amazing diversity of mollusks:  . MEDIA Click image to the left or use the URL below. URL: "
Traits of mollusks include a(n),(A) pseudocoelom (B) incomplete digestive system (C) distinct head region (D) all of the above,C,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
The teeth of a sea slug are made of,(A) bone (B) chitin (C) cuticle (D) cellulose,B,"The Mollusks body is often divided into different parts ( Figure 1.2): On the beach, you can find a wide variety of mollusk shells. 1. A head with eyes or tentacles. 2. In most species, a muscular foot, which helps the mollusk move. Some mollusks use the foot for burrowing into the sand, and others use it for jet-propulsion. 3. A mantle, or fold of the outer skin lining the shell. The mantle often releases calcium carbonate, which creates an external shell, just like the ones you find on the beach. The shell is made of chitin, a tough, semitransparent substance. 4. A mass housing the organs. 5. A complete digestive tract that begins at the mouth and runs to the anus. 6. Most ocean mollusks have a gill or gills to absorb oxygen from the water. 7. Many species have a feeding structure, the radula, found only in mollusks. The radula can be thought of as a ""tongue-like"" structure. The radula is made mostly of chitin. Types of radulae range from structures used to scrape algae off of rocks to the beaks of squid and octopuses. This is the basic body plan of a mollusk. Note the mantle, gills, and radula. Keep in mind the basic body plan can differ slightly among the mollusks. "
Which statement about mollusk reproduction is false?,(A) Mollusks may reproduce asexually or sexually (B) Fertilization may be internal or external (C) Most species have separate male and female sexes (D) Fertilized eggs develop into larvae before becoming adults,A,"Mollusks reproduce sexually. Most species have separate male and female sexes. Fertilization may be internal or external, depending on the species. Fertilized eggs develop into larvae. There may be one or more larval stages. Each one is different from the adult stage. "
Annelids have all of the following body systems except a(n),(A) circulatory system (B) excretory system (C) nervous system (D) incomplete digestive system,D,"Annelids have a large coelom. They also have several organ systems. These include a: circulatory system; excretory system; complete digestive system; and nervous system, with a brain and sensory organs. "
The body segments of annelids,(A) have their own nervous and muscle tissues (B) may be specialized for particular functions (C) may have structures such as tentacles or paddles (D) all of the above,D,"Annelids are divided into many repeating segments. The earthworm in Figure 12.18 is an annelid. You can clearly see its many segments. Segmentation of annelids is highly adaptive. Each segment has its own nerve and muscle tissues. This allows the animal to move very efficiently. Some segments can also be specialized to carry out particular functions. They may have special structures on them. For example, they might have tentacles for sensing or feeding, paddles for swimming, or suckers for clinging to surfaces. "
Earthworms get organic material by eating,(A) soil (B) plant roots (C) tiny invertebrates such as protozoa (D) two of the above,A,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
Vertebrate classes include,(A) birds (B) amphibians (C) reptiles (D) all of the above,D,"Vertebrates are animals with backbones. These include fish, amphibians, reptiles, birds, and mammals. "
"Of the nine classes of modern vertebrates, how many are fish?",(A) four (B) five (C) six (D) three,B,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
What function(s) does the vertebral column of vertebrates serve?,(A) It protects the spinal cord (B) It helps the body hold its shape (C) It provides a counterforce to muscles (D) all of the above,D,"The vertebral column is the core of the vertebrate endoskeleton, or internal skeleton. You can see a human skeleton as an example of the vertebrate endoskeleton in Figure 13.3. In addition to the vertebral column, the vertebrate endoskeleton includes: a cranium, or bony skull, that encloses and protects the brain; two pairs of limbs (in humans, arms and legs); limb girdles that connect the limbs to the rest of the endoskeleton (in humans, shoulders and hips). "
Which statement about the vertebral column of vertebrates is false?,(A) It runs along the top side of the body (B) It consists of a single rigid rod of bone (C) It protects the spinal cord that runs through it (D) It develops from the notochord after the embryonic stage,B,"The main trait that sets vertebrates apart from invertebrate chordates is their vertebral column, or backbone. It develops from the notochord after the embryonic stage. As you can see in Figure 13.2 the vertebral column runs from head to tail along the dorsal (top) side of the body. The vertebral column is made up of repeating units of bone called vertebrae (vertebra, singular). The vertebral column helps the vertebrate body hold its shape. It also protects the spinal (nerve) cord that runs through it. "
Most vertebrates have four,(A) limbs (B) limb girdles (C) kidneys (D) two of the above,A,"Vertebrates are animals with backbones. These include fish, amphibians, reptiles, birds, and mammals. "
The vertebrate endoskeleton includes,(A) a cranium (B) two limbs (C) a long tail (D) two of the above,A,"The vertebral column is the core of the vertebrate endoskeleton, or internal skeleton. You can see a human skeleton as an example of the vertebrate endoskeleton in Figure 13.3. In addition to the vertebral column, the vertebrate endoskeleton includes: a cranium, or bony skull, that encloses and protects the brain; two pairs of limbs (in humans, arms and legs); limb girdles that connect the limbs to the rest of the endoskeleton (in humans, shoulders and hips). "
"Compared with cartilage, bone is",(A) more fragile (B) stronger (C) less flexible (D) two of the above,D,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
Which reproductive strategy is used by most mammals?,(A) ovipary (B) ovovivipary (C) vivipary (D) none of the above,C,"Mammals have separate sexes and reproduce sexually. They produce eggs or sperm and must mate in order for fertilization to occur. A few mammals are oviparous. They lay eggs, which later hatch. These mammals are called monotremes. Most mammals are viviparous and give birth to live young. These mammals are either placental mammals or marsupials. Placental mammals give birth to relatively large and well-developed fetuses. Marsupials give birth to smaller, less-developed embryos. In both placental and marsupial mammals, the young grow and develop inside the mothers body in an organ called the uterus. At birth, they pass through a tube-like organ called the birth canal, or vagina. "
Vertebrates have an endocrine system with glands that secrete,(A) messenger molecules (B) digestive enzymes (C) DNA molecules (D) reproductive cells,A,"Most vertebrates share several other traits. The majority of vertebrates have: scales, feathers, fur, or hair covering their skin; muscles attached to the endoskeleton to allow movement; a circulatory system with a heart that pumps blood through a closed network of blood vessels; an excretory system that includes a pair of kidneys for filtering wastes out of the blood; a central nervous system with a brain, spinal cord, and nerve fibers throughout the body; an adaptive immune system that learns to recognize specific pathogens and launch tailor-made attacks against them; and an endocrine system with glands that secrete chemical messenger molecules called hormones. "
The first vertebrates were,(A) amphibians (B) reptiles (C) fish (D) birds,C,The earliest vertebrates were jawless fish. They evolved about 550 million years ago. They were probably similar to modern hagfish (see Table 13.1). The tree diagram in Figure 13.4 summarizes how vertebrates evolved from that time forward. 
Which statement about vertebrate reproduction is false?,(A) All vertebrates reproduce sexually (B) Most vertebrates have separate male and female sexes (C) All vertebrates have the same reproductive strategy (D) Some vertebrates lay eggs,C,"Vertebrates reproduce sexually. Most have separate male and female sexes. Vertebrates have one of three reproduc- tive strategies: ovipary, ovovivipary, or vivipary. Ovipary refers to the development of an embryo within an egg outside the mothers body. This occurs in most fish, amphibians, and reptiles. It also occurs in all birds. Ovovivipary refers to the development of an embryo inside an egg within the mothers body. The egg remains inside the mothers body until it hatches, but the mother provides no nourishment to the developing embryo inside the egg. This occurs in some species of fish and reptiles. Vivipary refers to the development and nourishment of an embryo within the mothers body but not inside an egg. Birth may be followed by a period of parental care of the offspring. This reproductive strategy occurs in almost all mammals including humans. "
The earliest vertebrates to evolve were,(A) bony fish (B) jawless fish (C) cartilaginous fish (D) amphibians,B,The earliest vertebrates were jawless fish. They evolved about 550 million years ago. They were probably similar to modern hagfish (see Table 13.1). The tree diagram in Figure 13.4 summarizes how vertebrates evolved from that time forward. 
Amphibians were the first vertebrates that did not need water to reproduce.,(A) true (B) false,B,"The earliest amphibians evolved from a lobe-finned fish ancestor. This occurred about 365 million years ago. Amphibians were the first terrestrial vertebrates. They lived on land as adults, but they had to return to the water to reproduce. The earliest reptiles evolved from an amphibian ancestor. This occurred at least 300 million years ago. Reptiles were the first vertebrates that did not need water to reproduce. Thats because they laid waterproof amniotic eggs. These eggs allowed the embryo inside to breathe without drying out. Mammals and birds both evolved from reptile-like ancestors. The first mammals appeared about 200 million years ago. The earliest birds evolved about 150 million years ago. "
Vertebrates evolved endothermy before they evolved ectothermy.,(A) true (B) false,B,"Early vertebrates were ectothermic. Ectothermy means controlling body temperature to just a limited extent from the outside by changing behavior. For example, an ectotherm might stay in the shade to keep cool on a hot, sunny day. On a cold day, an ectotherm might bask in the sun to warm up, like the snake in Figure 13.5. Almost all living fish, amphibians, and reptiles are ectothermic. They can raise or lower their body temperature by their behavior but not by very much. In cold weather, an ectotherm cools down. As its body temperature drops, its metabolism slows down and it becomes inactive. Both mammals and birds evolved endothermy. Endothermy means controlling body temperature within a narrow range from the inside through biochemical or physical means. For example, on a cold day, an endotherm may produce more body heat by increasing its rate of metabolism. On a hot day, it may give off more heat by increasing blood flow to the surface of the body. That way, some of the heat can radiate into the air from the bodys surface. Endothermy requires more energy (and food) than ectothermy. However, it allows the animal to stay active regardless of the temperature outside. You can learn more about how vertebrates regulate their temperature by watching this video:  . "
Amphibians evolved from a lobe-finned fish ancestor.,(A) true (B) false,A,"The lobe-finned fish are characterized by fleshy lobed fins, as opposed to the bony fins of the ray-finned fish. There are two types of living lobe-finned fish: the coelacanths and the lungfish. The pectoral and pelvic fins have joints resembling those of tetrapod (four-limbed land vertebrates) limbs. These fins evolved into legs of amphibians, the first tetrapod land vertebrates. They also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of ray-finned fish. All lobe-finned fishes possess teeth covered with true enamel. The lungfish also possess both gills and lungs, solidifying this class as the ancestors of amphibians. "
All animals in Phylum Chordata are vertebrates.,(A) true (B) false,B,"Did you know that fish, amphibians, reptiles, birds, and mammals are all related? They are all chordates. Chordates are a group of animals that includes vertebrates, as well as several closely related invertebrates. Chordates (phylum Chordata) are named after a feature they all share, a notochord. A notochord is a hollow nerve cord along the back. "
The function of vertebrate kidneys is filtering wastes out of the blood.,(A) true (B) false,A,"The kidneys ( Figure 1.1) are important organs in maintaining homeostasis, the ability of the body to maintain a stable internal environment despite a changing environment. Kidneys perform a number of homeostatic functions. They maintain the volume of body fluids. They maintain the balance of salt ions in body fluids. They excrete harmful nitrogen-containing molecules, such as urea, ammonia, and uric acid. There are many blood vessels in the kidneys ( Figure 1.1). The kidneys remove urea and other wastes from the blood through tiny filtering units called nephrons. Nephrons ( Figure 1.2) are tiny, tube-shaped structures found inside each kidney. Each kidney has up to a million nephrons. Each nephron collects a small amount of fluid and waste from a small group of capillaries. Structures of the kidney; fluid leaks from the capillaries and into the nephrons where the fluid forms urine then moves to the ureter and on to the bladder. Nitrogen-containing wastes, together with water and other wastes, form the urine as it passes through the nephrons and the kidney. The fluid within nephrons is carried out into a larger tube in the kidney called a ureter, which carries it to the bladder ( Figure 1.2). The kidneys never stop filtering waste products from the blood, so they are always producing urine. The amount of urine your kidneys produce is dependent on the amount of fluid in your body. Your body loses water through sweating, breathing, and urination. The water and other fluids you drink every day help to replace the lost water. This water ends up circulating in the blood because blood plasma is mostly water. "
The adaptive immune system of vertebrates learns to recognize and attack specific pathogens.,(A) true (B) false,A,"Some defenses, like your skin and mucous membranes, are not designed to ward off a specific pathogen. They are just general defenders against disease. Your body also has defenses that are more specialized. Through the help of your immune system, your body can generate an army of cells to kill that one specific pathogen. There are two different types of specific immune responses. One type involves B cells. The other type involves T cells. Recall that B cells and T cells are types of white blood cells that are key in the immune response. Whereas the immune systems first and second line of defense are more generalized or non-specific, the immune response is specific. It can be described as a specific response to a specific pathogen, meaning it uses methods to target just one pathogen at a time. These methods involve B and T cells. "
The earliest fish had a cartilage endoskeleton.,(A) true (B) false,A,"The earliest fish had an endoskeleton made of cartilage rather than bone. They also lacked a complete vertebral column. The first fish with a complete vertebral column evolved about 450 million years ago. These fish had jaws. They may have been similar to living sharks. About 400 million years ago, the first fish with a bony endoskeleton evolved. A bony skeleton could support a bigger body. Early bony fish evolved into modern ray-finned fish and lobe-finned fish. "
Birds evolved before the first mammals appeared.,(A) true (B) false,B,"The earliest amphibians evolved from a lobe-finned fish ancestor. This occurred about 365 million years ago. Amphibians were the first terrestrial vertebrates. They lived on land as adults, but they had to return to the water to reproduce. The earliest reptiles evolved from an amphibian ancestor. This occurred at least 300 million years ago. Reptiles were the first vertebrates that did not need water to reproduce. Thats because they laid waterproof amniotic eggs. These eggs allowed the embryo inside to breathe without drying out. Mammals and birds both evolved from reptile-like ancestors. The first mammals appeared about 200 million years ago. The earliest birds evolved about 150 million years ago. "
An animal with a cartilage skeleton can grow larger than an animal with a bony skeleton.,(A) true (B) false,B,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
There are more than a million living species of vertebrates.,(A) true (B) false,B,There are over 1 million species of plants and animals living on Earth today. Scientists think that there are millions more that have not yet been discovered. 
Living species of vertebrates are placed in five different classes.,(A) true (B) false,B,"Vertebrates are animals with backbones. These include fish, amphibians, reptiles, birds, and mammals. "
Most vertebrates have separate male and female sexes.,(A) true (B) false,A,"Vertebrates reproduce sexually. Most have separate male and female sexes. Vertebrates have one of three reproduc- tive strategies: ovipary, ovovivipary, or vivipary. Ovipary refers to the development of an embryo within an egg outside the mothers body. This occurs in most fish, amphibians, and reptiles. It also occurs in all birds. Ovovivipary refers to the development of an embryo inside an egg within the mothers body. The egg remains inside the mothers body until it hatches, but the mother provides no nourishment to the developing embryo inside the egg. This occurs in some species of fish and reptiles. Vivipary refers to the development and nourishment of an embryo within the mothers body but not inside an egg. Birth may be followed by a period of parental care of the offspring. This reproductive strategy occurs in almost all mammals including humans. "
__development of an embryo in an egg outside the mothers body,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,G,Amphibians reproduce sexually. Fertilization may take place inside or outside the body. Amphibians are oviparous. Embryos develop in eggs outside the mothers body. 
__use of behavior to control body temperature from the outside,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,D,"When you are cold, what does your body do to keep warm? You shiver to warm up your body. When you are too warm, you sweat to release heat. When any living organism gets thrown off balance, its body or cells help it return to normal. In other words, living organisms have the ability to keep a stable internal environment. Maintaining a balance inside the body or cells of organisms is known as homeostasis. Like us, many animals have evolved behaviors that control their internal temperature. A lizard may stretch out on a sunny rock to increase its internal temperature, and a bird may fluff its feathers to stay warm ( Figure 1.5). A bird fluffs its feathers to stay warm and to maintain homeostasis. "
__reproductive strategy that occurs in almost all mammals,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,E,"Vertebrates reproduce sexually. Most have separate male and female sexes. Vertebrates have one of three reproduc- tive strategies: ovipary, ovovivipary, or vivipary. Ovipary refers to the development of an embryo within an egg outside the mothers body. This occurs in most fish, amphibians, and reptiles. It also occurs in all birds. Ovovivipary refers to the development of an embryo inside an egg within the mothers body. The egg remains inside the mothers body until it hatches, but the mother provides no nourishment to the developing embryo inside the egg. This occurs in some species of fish and reptiles. Vivipary refers to the development and nourishment of an embryo within the mothers body but not inside an egg. Birth may be followed by a period of parental care of the offspring. This reproductive strategy occurs in almost all mammals including humans. "
"__tough, flexible tissue that contains collagen",(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,C,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
__use of biology to control body temperature from the inside,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,F,"When you are cold, what does your body do to keep warm? You shiver to warm up your body. When you are too warm, you sweat to release heat. When any living organism gets thrown off balance, its body or cells help it return to normal. In other words, living organisms have the ability to keep a stable internal environment. Maintaining a balance inside the body or cells of organisms is known as homeostasis. Like us, many animals have evolved behaviors that control their internal temperature. A lizard may stretch out on a sunny rock to increase its internal temperature, and a bird may fluff its feathers to stay warm ( Figure 1.5). A bird fluffs its feathers to stay warm and to maintain homeostasis. "
__hard tissue that contains minerals in a collagen framework,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,A,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
__development of an embryo in an egg inside the mothers body,(A) abone (B) bovovivipary (C) ccartilage (D) dectothermy (E) evivipary (F) fendothermy (G) govipary,B,"The zygote spends the next few days traveling down the fallopian tube toward the uterus, where it will take up residence. As it travels, it divides many times by mitosis. It soon forms a tiny, fluid-filled ball of cells called a blastocyst. The blastocyst has an inner and outer layer of cells, as you can see in Figure 22.5. The inner layer, called the embryoblast, will develop into the new human being. The outer layer, called the trophoblast, will develop into other structures needed to support the new organism. "
Fish are all of the following except,(A) aquatic animals (B) chordate animals (C) invertebrate animals (D) ectothermic animals,C,Fish are aquatic vertebrates. They make up more than half of all living vertebrate species. Most fish are ectothermic. They share several adaptations that suit them for life in the water. 
Which statement about fish is false?,(A) Most fish are endothermic (B) Fish have a nervous system with a brain (C) Fish make up more than half of all living vertebrate species (D) Fish brains are small compared with the brains of other vertebrates,A,Fish are aquatic vertebrates. They make up more than half of all living vertebrate species. Most fish are ectothermic. They share several adaptations that suit them for life in the water. 
Fish generally have,(A) sexual reproduction (B) external fertilization (C) separate sexes (D) all of the above,D,"Fish have a circulatory system with a heart. They also have a complete digestive system. It includes several organs and other structures. Fish with jaws use their jaws and teeth to chew food before swallowing it. This allows them to eat larger prey animals. Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste. "
What happens when a fish deflates its swim bladder?,(A) It sinks in the water (B) It floats on its back (C) It shoots out toxins (D) It excretes urine,A,"Scuba divers can dive without special vehicles because they dont go very deep below the surface of the water. Nonetheless, because of the pressure of the water, scuba divers who go deeper than about 40 meters must return to the surface slowly. They must stop for several minutes at one or more points in their ascent. Thats what the divers in the Figure 1.2 are doing. The stops are needed to let the pressure inside their body adjust to the decreasing pressure of the water as they swim closer to the surface. If they were to rise to the surface too quickly, the gases dissolved in their blood would form bubbles and cause serious health problems. Q: Why would dissolved gases form bubbles as pressure decreases? A: Less gas can dissolve in a fluid at lower pressure. Therefore, as pressure decreases, gases come out of solution and form bubbles. "
Fish with jaws,(A) can eat larger prey (B) evolved before jawless fish (C) have smaller brains than other fish (D) two of the above,A,"The 1,000 or so species of cartilaginous fish are subdivided into two subclasses: the first includes sharks, rays, and skates; the second includes chimaera, sometimes called ghost sharks. Fish from this group range in size from the dwarf lanternshark, at 6.3 inches, to the over 50-foot whale shark. Sharks obviously have jaws, as do the other cartilaginous fish. These fish evolved from the jawless fish. So why did fish eventually evolve to have jaws? Such an adaptation would allow fish to eat a much wider variety of food, including plants and other organisms. Other characteristics of cartilaginous fish include: Paired fins. Paired nostrils. Scales. Two-chambered hearts. Skeletons made of cartilage rather than bone. Cartilage is supportive tissue that does not have as much calcium as bones, which makes bones rigid. Cartilage is softer and more flexible than bone. "
Fish larvae swim around attached to,(A) their mother (B) a yolk sac (C) each other (D) none of the above,B,Fish eggs hatch into larvae. Each larva swims around attached to a yolk sac from the egg (see Figure 13.9). The yolk sac provides it with food. Fish larvae look different from adult fish of the same species. They must go through metamorphosis to change into the adult form. 
Which class(es) of fish lack scales?,(A) hagfish (B) lampreys (C) bony fish (D) two of the above,D,"There are about 28,000 living species of fish. They are placed in five different classes. The classes are commonly called hagfish, lampreys, cartilaginous fish, ray-finned fish, and lobe-finned fish. Table 13.2 shows pictures of fish in each class. It also provides additional information about the classes. Class Hagfish Lampreys Cartilaginous Fish Distinguishing Traits Hagfish are very primitive fish. They lack scales and fins. They even lack a backbone, but they do have a cranium. They secrete large amounts of thick, slimy mucus. This makes them slippery, so they can slip out of the jaws of predators. Lampreys lack scales but have fins and a partial backbone. Their mouth is surrounded by a large round sucker with teeth. They use the sucker to suck the blood of other fish. Example hagfish Cartilaginous fish include sharks, rays, and ratfish. Their endoskele- ton is made of cartilage instead of bone. They also lack a swim blad- der. However, they have a complete vertebral column and jaws. They also have a relatively big brain. shark lampreys Class Ray-Finned Fish Lobe-Finned Fish Distinguishing Traits Ray-finned fish make up the ma- jority of living fish species. They are a type of bony fish, with an en- doskeleton made of bone instead of cartilage. Their fins consist of webs of skin over flexible bony spines, called rays. They have a swim blad- der. Lobe-finned fish include only coelacanths and lungfish. They are bony fish with an endoskeleton made of bone. Their fleshy fins contain bone and muscle. Lungfish are named for a lung-like organ that they can use for breathing air. It evolved from the swim bladder. It allows them to survive for long periods of time out of water. Example puffer lungfish "
Spawning occurs when many fish group together and,(A) fight for mates (B) release gametes (C) defend territory (D) change to adults,B,"Many species of fish reproduce by spawning. Spawning occurs when many adult fish group together and release their sperm or eggs into the water at the same time. You can see fish spawning in Figure 13.8. Spawning increases the changes that fertilization will take place. It typically results in a large number of embryos forming at once. This makes it more likely that at least some of the embryos will avoid being eaten by predators. You can watch trout spawning in Yellowstone Park in this interesting video: http://video.nationalgeographic.com/video/trout_spawning MEDIA Click image to the left or use the URL below. URL:  With spawning, fish parents cant identify their own offspring. Therefore, in most species, there is no parental care of offspring. However, there are exceptions. Some species of fish carry their fertilized eggs in their mouth until they "
Cartilaginous fish such as sharks lack,(A) a vertebral column (B) jaws (C) a swim bladder (D) fins,C,"The 1,000 or so species of cartilaginous fish are subdivided into two subclasses: the first includes sharks, rays, and skates; the second includes chimaera, sometimes called ghost sharks. Fish from this group range in size from the dwarf lanternshark, at 6.3 inches, to the over 50-foot whale shark. Sharks obviously have jaws, as do the other cartilaginous fish. These fish evolved from the jawless fish. So why did fish eventually evolve to have jaws? Such an adaptation would allow fish to eat a much wider variety of food, including plants and other organisms. Other characteristics of cartilaginous fish include: Paired fins. Paired nostrils. Scales. Two-chambered hearts. Skeletons made of cartilage rather than bone. Cartilage is supportive tissue that does not have as much calcium as bones, which makes bones rigid. Cartilage is softer and more flexible than bone. "
All of the following classes of fish have fins except for,(A) lampreys (B) hagfish (C) cartilaginous fish (D) bony fish,B,"There are about 27,000 species of bony fish ( Figure 1.1), which are divided into two classes: ray-finned fish and lobe-finned fish. Most bony fish are ray-finned. These thin fins consist of webs of skin over flexible spines. Lobe- finned fish, on the other hand, have fins that resemble stump-like appendages. Fins of bony fish: ray fin (left) and lobe fin (right). "
Most modern fish are,(A) bony fish (B) cartilaginous fish (C) hagfish (D) lampreys,A,Fish are aquatic vertebrates. They make up more than half of all living vertebrate species. Most fish are ectothermic. They share several adaptations that suit them for life in the water. 
The majority of fish are,(A) decomposers (B) parasites (C) predators (D) producers,C,Fish are aquatic vertebrates. They make up more than half of all living vertebrate species. Most fish are ectothermic. They share several adaptations that suit them for life in the water. 
Fish have a circulatory system with a heart.,(A) true (B) false,A,"Fish have a circulatory system with a heart. They also have a complete digestive system. It includes several organs and other structures. Fish with jaws use their jaws and teeth to chew food before swallowing it. This allows them to eat larger prey animals. Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste. "
Fish can see and hear but they cant smell or taste.,(A) true (B) false,B,"Fish have a circulatory system with a heart. They also have a complete digestive system. It includes several organs and other structures. Fish with jaws use their jaws and teeth to chew food before swallowing it. This allows them to eat larger prey animals. Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste. "
A fish embryo develops in an egg inside the mothers body.,(A) true (B) false,B,"Almost all fish have sexual reproduction, generally with separate sexes. Each fish typically produces large numbers of sperm or eggs. Fertilization takes place in the water outside the body in the majority of fish. Most fish are oviparous. The embryo develops in an egg outside the mothers body. "
Mouth brooding refers to a form of predation in some species of fish.,(A) true (B) false,B,"Predation is a relationship in which members of one species consume members of another species. The consuming species is called the predator. The species that is consumed is called the prey. In Figure 23.8, the wolves are predators, and the moose is their prey. "
Fish have a nervous system with a brain.,(A) true (B) false,A,"Fish have a circulatory system with a heart. They also have a complete digestive system. It includes several organs and other structures. Fish with jaws use their jaws and teeth to chew food before swallowing it. This allows them to eat larger prey animals. Fish have a nervous system with a brain. Fish brains are small compared with the brains of other vertebrates. However, they are large and complex compared with the brains of invertebrates. Fish also have highly developed sense organs. They include organs to see, hear, feel, smell, and taste. "
Almost all fish have internal fertilization of gametes.,(A) true (B) false,B,"Almost all fish have sexual reproduction, generally with separate sexes. Each fish typically produces large numbers of sperm or eggs. Fertilization takes place in the water outside the body in the majority of fish. Most fish are oviparous. The embryo develops in an egg outside the mothers body. "
"There are about 28,000 living species of fish.",(A) true (B) false,A,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
Most fish parents provide care to their offspring.,(A) true (B) false,B,"In most species of birds and mammals, one or both parents care for the young. This may include building a nest or other shelter. It may also include feeding the young and protecting them from predators. Caring for the young increases their chances of surviving. This, in turn, increases the parents fitness, so such behaviors evolve by natural selection. Emperor penguins make great sacrifices to take care of their young. After laying an egg, a penguin mother returns to the sea for two months to feed. Her mate stays behind to keep the egg warm. He balances the egg on top of his feet to keep it warm for the entire time the mother is away. During this time, he goes without food. To survive the cold, he huddles together with other males. If the chick hatches before the mother returns, the father feeds it with a high-protein, high-fat substance he produces just for this purpose. You can see an emperor penguin father feeding his chick in Figure 15.17. "
Hagfish have a backbone but lack a cranium.,(A) true (B) false,B,"Jawless fish are missing the following parts: 1. Jaws. 2. Paired fins. 3. A stomach. Characteristics they do have include: 1. A notochord, both in larvae and adults. Recall a notochord is a support rod that runs along the back of the fish. 2. Seven or more paired gill pouches. These organs take dissolved oxygen from water. 3. The branchial arches, a series of arches that support the gills of aquatic amphibians and fishes. They lie close to the bodys surface. 4. A light sensitive pineal eye, an eye-like structure that can detect light. 5. A cartilaginous skeleton, a skeleton made of a flexible rubber-like supportive material called cartilage. This is similar to the skeleton of cartilaginous fish, which includes sharks and rays. 6. A heart with two chambers. 7. Reproduction using external fertilization. 8. They are ectothermic. This means that their internal temperature depends on the temperature of their envi- ronment. "
Bony fish include ray-finned fish and lobe-finned fish.,(A) true (B) false,A,"There are about 27,000 species of bony fish ( Figure 1.1), which are divided into two classes: ray-finned fish and lobe-finned fish. Most bony fish are ray-finned. These thin fins consist of webs of skin over flexible spines. Lobe- finned fish, on the other hand, have fins that resemble stump-like appendages. Fins of bony fish: ray fin (left) and lobe fin (right). "
Fish larvae look like miniature versions of the adults.,(A) true (B) false,B,Fish eggs hatch into larvae. Each larva swims around attached to a yolk sac from the egg (see Figure 13.9). The yolk sac provides it with food. Fish larvae look different from adult fish of the same species. They must go through metamorphosis to change into the adult form. 
Ray-finned fish make up the majority of living fish species.,(A) true (B) false,A,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
__inflatable fish organ that allows a fish to rise or sink in the water,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,C,"You can see some of the aquatic adaptations of fish in Figure 13.7. For a video introduction to aquatic adaptations of fish, go to this link:  . MEDIA Click image to the left or use the URL below. URL:  Fish are covered with scales. Scales are overlapping tissues, like shingles on a roof. They reduce friction with the water. They also provide a flexible covering that lets fish move their body to swim. Fish have gills. Gills are organs behind the head that absorb oxygen from water. Water enters through the mouth, passes over the gills, and then exits the body. Fish typically have a stream-lined body. This reduces water resistance. Most fish have fins. Fins function like paddles or rudders. They help fish swim and navigate in the water. Most fish have a swim bladder. This is a balloon-like organ containing gas. By inflating or deflating their swim bladder, fish can rise or sink in the water. "
__common reproductive behavior in fish,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,E,"Almost all fish have sexual reproduction, generally with separate sexes. Each fish typically produces large numbers of sperm or eggs. Fertilization takes place in the water outside the body in the majority of fish. Most fish are oviparous. The embryo develops in an egg outside the mothers body. "
__fish organ that functions like a paddle or rudder,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,F,"You can see some of the aquatic adaptations of fish in Figure 13.7. For a video introduction to aquatic adaptations of fish, go to this link:  . MEDIA Click image to the left or use the URL below. URL:  Fish are covered with scales. Scales are overlapping tissues, like shingles on a roof. They reduce friction with the water. They also provide a flexible covering that lets fish move their body to swim. Fish have gills. Gills are organs behind the head that absorb oxygen from water. Water enters through the mouth, passes over the gills, and then exits the body. Fish typically have a stream-lined body. This reduces water resistance. Most fish have fins. Fins function like paddles or rudders. They help fish swim and navigate in the water. Most fish have a swim bladder. This is a balloon-like organ containing gas. By inflating or deflating their swim bladder, fish can rise or sink in the water. "
__most primitive class of fish,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,A,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
__fish organ that absorbs oxygen from water,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,G,"In order to absorb oxygen from the water, fish use gills ( Figure 1.2). Gills take dissolved oxygen from water as the water flows over the surface of the gill. Gills help a fish breathe. "
__fish class that includes sharks,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,D,"Fish range in size from the 65-foot, 75,000 pound whale shark ( Figure 1.3) to the stout infantfish, which is about 0.33 inches (8.4 mm), and the Paedocypris progenetica carp species of the Indonesian island of Sumatra, which is about 0.31 inches (7.9 mm) long, making it also the smallest known vertebrate animal. The second-largest fish is the basking shark, which grows to about 40 feet and 8,000 pounds. Both of the large sharks may look ferocious, and would probably scare anyone who comes across one in the water, but both species are filter-feeders, and feed on tiny fish and plankton. The tiny carp species is unique in that it has the appearance of larvae, with a reduced skeleton lacking a cranium, which leaves the brain unprotected by bone. The fish lives in dark acidic waters, having a pH of 3. Keep in mind that whales are not fish, they are mammals. "
__ray-finned or lobe-finned fish,(A) ahagfish (B) bbony fish (C) cswim bladder (D) dcartilaginous fish (E) espawning (F) ffin (G) ggill,B,"There are about 27,000 species of bony fish ( Figure 1.1), which are divided into two classes: ray-finned fish and lobe-finned fish. Most bony fish are ray-finned. These thin fins consist of webs of skin over flexible spines. Lobe- finned fish, on the other hand, have fins that resemble stump-like appendages. Fins of bony fish: ray fin (left) and lobe fin (right). "
Functions of epithelial tissue include,(A) secreting hormones (B) absorbing substances (C) protecting internal organs (D) all of the above,D,"Cells are grouped together to carry out specific functions. A group of cells that work together form a tissue. Your body has four main types of tissues, as do the bodies of other animals. These tissues make up all structures and contents of your body. An example of each tissue type is pictured in the Figure 1.1. Your body has four main types of tissue: nervous tissue, epithelial tissue, connective tissue, and muscle tissue. They are found throughout your body. 1. Epithelial tissue is made up of layers of tightly packed cells that line the surfaces of the body. Examples of epithelial tissue include the skin, the lining of the mouth and nose, and the lining of the digestive system. 2. Connective tissue is made up of many different types of cells that are all involved in supporting and binding other tissues of the body. Examples include tendon, cartilage, and bone. Blood is also classified as a specialized connective tissue. 3. Muscle tissue is made up of bands of cells that contract and allow movement. 4. Nervous tissue is made up of nerve cells that sense stimuli and transmit signals. Nervous tissue is found in nerves, the spinal cord, and the brain. "
__type of tissue that includes bone and cartilage,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,G,"Bones come in many different shapes and sizes, but they are all made of the same materials. Bones are organs, and recall that organs are made up of two or more types of tissues. The two main types of bone tissue are compact bone and spongy bone ( Figure 1.2). Compact bone makes up the dense outer layer of bones. Spongy bone is found at the center of the bone and is lighter and more porous than compact bone. Bones look tough, shiny, and white because they are covered by a layer called the periosteum. Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Bones are made up of different types of tissues. "
__structure composed of two or more types of tissues that work together to do the same task,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,D,A single tissue alone cannot do all the jobs that are needed to keep you alive and healthy. Two or more tissues working together can do a lot more. An organ is a structure made of two or more tissues that work together. The heart ( Figure 1.2) is made up of the four types of tissues. The four different tissue types work to- gether in the heart as they do in the other organs. 
The brain and spinal cord consist mainly of,(A) connective tissue (B) muscle tissue (C) nervous tissue (D) epithelial tissue,C,"The central nervous system (CNS) ( Figure 1.1) is the largest part of the nervous system. It includes the brain and the spinal cord. The bony skull protects the brain. The spinal cord is protected within the bones of the spine, which are called vertebrae. "
Which human organ system carries wastes away from cells?,(A) respiratory system (B) nervous system (C) digestive system (D) circulatory system,D,"So what happens to your bodys wastes? Obviously, you must get rid of them. This is the job of the excretory system. You remove waste as a gas (carbon dioxide), as a liquid (urine and sweat), and as a solid. Excretion is the process of removing wastes and excess water from the body. Recall that carbon dioxide travels through the blood and is transferred to the lungs where it is exhaled. In the large intestine, the remains of food are turned into solid waste for excretion. How is waste other than carbon dioxide removed from the blood? That is the role of the kidneys. Urine is a liquid waste formed by the kidneys as they filter the blood. If you are getting plenty of fluids, your urine should be almost clear. But you might have noticed that sometimes your urine is darker than usual. Do you know why this happens? Sometimes your body is low on water and trying to reduce the amount of water lost in urine. Therefore, your urine gets darker than usual. Your body is striving to maintain homeostasis through the process of excretion. Urine helps remove excess water, salts, and nitrogen from your body. Your body also needs to remove the wastes that build up from cell activity and from digestion. If these wastes are not removed, your cells can stop working, and you can get very sick. The organs of your excretory system help to release wastes from the body. The organs of the excretory system are also parts of other organ systems. For example, your lungs are part of the respiratory system. Your lungs remove carbon dioxide from your body, so they are also part of the excretory system. More organs of the excretory system are listed below ( Table 1.1). Organ(s) Function Lungs Skin Remove carbon dioxide. Sweat glands remove water, salts, and other wastes. Removes solid waste and some wa- ter in the form of feces. Remove urea, salts, and excess wa- ter from the blood. Large intestine Kidneys Component of Other Organ Sys- tem Respiratory system Integumentary system Digestive system Urinary system "
__type of tissue that consists of cells that can contract,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,B,"Specialized cells are organized into tissues. A tissue is a group of specialized cells of the same kind that perform the same function. There are four basic types of human tissues: connective, epithelial, muscle, and nervous tissues. The four types are shown in Figure 16.2. Connective tissue consists of cells that form the bodys structure. Examples include bone and cartilage, which protect and support the body. Blood is also a connective tissue. It circulates and connects cells throughout the body. Epithelial tissue consists of cells that cover inner and outer body surfaces. Examples include skin and the linings of internal organs. Epithelial tissue protects the body and its internal organs. It also secretes substances such as hormones and absorbs substances such as nutrients. Muscle tissue consists of cells that can contract, or shorten. Examples include skeletal muscle, which is attached to bones and makes them move. Other types of muscle include cardiac muscle, which makes the heart beat, and smooth muscle, which is found in other internal organs. Nervous tissue consists of nerve cells, or neurons, which can send and receive electrical messages. Nervous tissue makes up the brain, spinal cord, and other nerves that run throughout the body. "
__one of the basic building blocks of the human body,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,C,"The basic building blocks of the human body are cells. Human cells are organized into tissues, tissues are organized into organs, and organs are organized into organ systems. "
The human organ system that controls virtually all body activities is the,(A) skeletal system (B) muscular system (C) nervous system (D) none of the above,C,"The human brain is an amazing organ. It is the most complex organ in the human body. By adulthood, the brain weighs about 3 pounds and consists of billions of neurons. All those cells need a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body! The brain serves as the control center of the nervous system and the body as a whole. It lets us understand what we see, hear, or sense in other ways. It allows us to learn, think, remember, and use language. It controls all the organs and muscles in our body. "
__type of tissue that can send and receive electrical messages,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,A,"The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron ( Figure 1.1). The messages carried by neurons are called nerve impulses. Nerve impulses can travel very quickly because they are electrical impulses. Think about flipping on a light switch when you enter a room. When you flip the switch, the electricity flows to the light through wires inside the walls. The electricity may have to travel many meters to reach the light, but the light still comes on as soon as you flip the switch. Nerve impulses travel just as fast through the network of nerves inside the body. The axons of many neurons, like the one shown here, are covered with a fatty layer called myelin sheath. The sheath covers the axon, like the plastic covering on an electrical wire, and allows nerve impulses to travel faster along the axon. The node of Ranvier, shown in this diagram, is any gap in the myelin sheath; it allows faster transmission of a signal. "
The condition in which the bodys internal environment is kept stable is called,(A) organization (B) specialization (C) homeostasis (D) maintenance,C,"When you walk outside on a cool day, does your body temperature drop? No, your body temperature stays stable at around 98.6 degrees Fahrenheit. Even when the temperature around you changes, your internal temperature stays the same. This ability of the body to maintain a stable internal environment despite a changing environment is called home- ostasis. Homeostasis doesnt just protect against temperature changes. Other aspects of your internal environment also stay stable. For example, your body closely regulates your fluid balance. You may have noticed that if you are slightly dehydrated, your urine is darker. Thats because the urine is more concentrated and less water is mixed in with it. "
__any group of specialized cells of the same type that perform the same function,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,F,"A tissue is a group of specialized cells of the same kind that perform the same function. Modern plants have three major types of tissues. Theyre called dermal, ground, and vascular tissues. "
__type of tissue that covers inner and outer body surfaces,(A) anervous (B) bmuscle (C) ccell (D) dorgan (E) eepithelial (F) ftissue (G) gconnective,E,"Specialized cells are organized into tissues. A tissue is a group of specialized cells of the same kind that perform the same function. There are four basic types of human tissues: connective, epithelial, muscle, and nervous tissues. The four types are shown in Figure 16.2. Connective tissue consists of cells that form the bodys structure. Examples include bone and cartilage, which protect and support the body. Blood is also a connective tissue. It circulates and connects cells throughout the body. Epithelial tissue consists of cells that cover inner and outer body surfaces. Examples include skin and the linings of internal organs. Epithelial tissue protects the body and its internal organs. It also secretes substances such as hormones and absorbs substances such as nutrients. Muscle tissue consists of cells that can contract, or shorten. Examples include skeletal muscle, which is attached to bones and makes them move. Other types of muscle include cardiac muscle, which makes the heart beat, and smooth muscle, which is found in other internal organs. Nervous tissue consists of nerve cells, or neurons, which can send and receive electrical messages. Nervous tissue makes up the brain, spinal cord, and other nerves that run throughout the body. "
The basic units of structure and function of the human body are organs.,(A) true (B) false,B,"The basic building blocks of the human body are cells. Human cells are organized into tissues, tissues are organized into organs, and organs are organized into organ systems. "
Most human cells are specialized for specific functions.,(A) true (B) false,A,"The average human adult consists of an incredible 100 trillion cells! Cells are the basic units of structure and function in the human body, as they are in all living things. Each cell must carry out basic life processes in order to survive and help keep the body alive. Most human cells also have characteristics for carrying out other, special functions. For example, muscle cells have extra mitochondria to provide the energy needed to move the body. You can see examples of these and some other specialized human cells in Figure 16.1. To learn more about specialized human cells and what they do, watch this video:  . MEDIA Click image to the left or use the URL below. URL: "
A tissue consists of four basic types of cells.,(A) true (B) false,B,"A tissue is a group of specialized cells of the same kind that perform the same function. Modern plants have three major types of tissues. Theyre called dermal, ground, and vascular tissues. "
The heart is an organ in the circulatory system.,(A) true (B) false,A,The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure 18.1 shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. 
The average human adult consists of about a billion cells.,(A) true (B) false,B,"The average human adult consists of an incredible 100 trillion cells! Cells are the basic units of structure and function in the human body, as they are in all living things. Each cell must carry out basic life processes in order to survive and help keep the body alive. Most human cells also have characteristics for carrying out other, special functions. For example, muscle cells have extra mitochondria to provide the energy needed to move the body. You can see examples of these and some other specialized human cells in Figure 16.1. To learn more about specialized human cells and what they do, watch this video:  . MEDIA Click image to the left or use the URL below. URL: "
Each cell of the body carries out basic life processes.,(A) true (B) false,A,"Cells are the basic building blocks of life. They are like tiny factories where virtually all life processes take place. Some living things, like the bacteria in Figure 2.1, consist of just one cell. They are called single-celled organisms. You can see other single-celled organisms in Figure 2.2. Some living things are composed of a few to many trillions of cells. They are called multicellular organisms. Your body is composed of trillions of cells. Regardless of the type of organism, all living cells share certain basic structures. For example, all cells are enclosed by a membrane. The cell membrane separates the cell from its environment. It also controls what enters or leaves the cell. "
Most human cells have specialized functions.,(A) true (B) false,A,"The average human adult consists of an incredible 100 trillion cells! Cells are the basic units of structure and function in the human body, as they are in all living things. Each cell must carry out basic life processes in order to survive and help keep the body alive. Most human cells also have characteristics for carrying out other, special functions. For example, muscle cells have extra mitochondria to provide the energy needed to move the body. You can see examples of these and some other specialized human cells in Figure 16.1. To learn more about specialized human cells and what they do, watch this video:  . MEDIA Click image to the left or use the URL below. URL: "
There are a total of five basic types of human tissues.,(A) true (B) false,B,"The four types of tissues make up all the organs of the human body. An organ is a structure composed of two or more types of tissues that work together to perform the same function. Examples of human organs include the skin, brain, lungs, kidneys, and heart. Consider the heart as an example. Figure 16.3 shows how all four tissue types work together to make the heart pump blood. "
The skin consists mainly of muscle tissue.,(A) true (B) false,B,"From the outside, the skin looks plain and simple, as you can see in Figure 16.5. But at a cellular level, theres nothing plain or simple about it. A single square inch of skin contains about 20 blood vessels, hundreds of sweat glands, and more than a thousand nerve endings. It also contains tens of thousands of pigment-producing cells. Clearly, there is much more to skin than meets the eye! For a dramatic introduction to the skin, watch this video: MEDIA Click image to the left or use the URL below. URL:  The skin is only about 2 mm thick, or about as thick as the cover of a book. Although it is very thin, it consists of two distinct layers, called the epidermis and the dermis. You can see both layers and some of their structures in Figure 16.6. Refer to the figure as you read about the epidermis and dermis below. "
Neurons are cells that can send and receive electrical messages.,(A) true (B) false,A,"The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons are called nerve impulses. A nerve impulse can travel very quickly because it is an electrical signal. Think about flipping on a light switch when you enter a room. When you flip the switch, electricity flows to the light through wires inside the walls. The electricity may have to travel many meters to reach the light. Nonetheless, the light still comes on as soon as you flip the switch. Nerve impulses travel just as quickly through the network of nerves inside the body. "
Smooth muscle tissue is found in the heart.,(A) true (B) false,B,"Smooth muscles and cardiac muscles are not attached to bone. Recall that these types of muscles are under involuntary control. Smooth muscle is responsible for the contractility of hollow organs, such as blood vessels, the gastrointestinal tract, the bladder, or the uterus. Like skeletal muscles, smooth muscle fibers do contract together, causing the muscle to shorten. Smooth muscles have numerous functions, including the following. The smooth muscle in the uterus helps a woman to push out her baby. In the bladder, smooth muscle helps to push out urine. Smooth muscles move food through the digestive tract. In arteries, smooth muscle movements maintain the arteries diameter. Smooth muscle regulates air flow in lungs. Smooth muscle in the lungs helps the airways to expand and contract as necessary. Smooth muscles in arteries and veins are largely responsible for regulation of blood pressure. Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. If your heart beats 75 times a minute, how many times does it beat in an hour? A day? A year? 85 years? "
Connective tissues are found in the walls of blood vessels.,(A) true (B) false,A,"Blood vessels are long, tube-like organs that consist mainly of muscle, connective, and epithelial tissues. They branch to form a complex network of vessels that run throughout the body. This network transports blood to all the bodys cells. "
Which of the following is a human connective tissue?,(A) skin (B) muscle (C) blood (D) none of the above,C,"Bones are the main organs of the skeletal system. In adults, the skeleton consists of a whopping 206 bones, many of them in the hands and feet. You can see many of the bones of the human skeleton in Figure 16.10. The skeletal system also includes cartilage and ligaments. Cartilage is a tough, flexible connective tissue that contains the protein collagen. It covers the ends of bones where they meet. The gray tissue in Figure 16.10 is cartilage. A ligament is a band of fibrous connective tissue. Ligaments connect bones of the skeleton and hold them together. "
The type of tissue that secretes hormones and absorbs nutrients is,(A) muscle tissue (B) nerve tissue (C) epithelial tissue (D) connective tissue,C,"Specialized cells are organized into tissues. A tissue is a group of specialized cells of the same kind that perform the same function. There are four basic types of human tissues: connective, epithelial, muscle, and nervous tissues. The four types are shown in Figure 16.2. Connective tissue consists of cells that form the bodys structure. Examples include bone and cartilage, which protect and support the body. Blood is also a connective tissue. It circulates and connects cells throughout the body. Epithelial tissue consists of cells that cover inner and outer body surfaces. Examples include skin and the linings of internal organs. Epithelial tissue protects the body and its internal organs. It also secretes substances such as hormones and absorbs substances such as nutrients. Muscle tissue consists of cells that can contract, or shorten. Examples include skeletal muscle, which is attached to bones and makes them move. Other types of muscle include cardiac muscle, which makes the heart beat, and smooth muscle, which is found in other internal organs. Nervous tissue consists of nerve cells, or neurons, which can send and receive electrical messages. Nervous tissue makes up the brain, spinal cord, and other nerves that run throughout the body. "
Types of muscle tissue include,(A) skeletal muscle (B) cardiac muscle (C) smooth muscle (D) all of the above,D,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
Nervous tissue makes up most of the,(A) lungs (B) kidneys (C) brain (D) stomach,C,"All the other nervous tissues in the body are part of the peripheral nervous system. If you look again at Figure 20.1, you can see the major nerves of the peripheral nervous system. They include nerves that run through virtually every part of the body, both inside and out, except for the brain and spinal cord. The peripheral nervous system has two main divisions: the sensory division and the motor division. The divisions carry messages in opposite directions. Figure 20.7 shows these divisions of the peripheral nervous system. "
How does the hormone insulin help maintain homeostasis in the human body?,(A) It helps cells absorb sugar from the blood after you eat and digest food (B) It stimulates the production of sweat on a hot day to cool the body (C) It controls the contractions of cardiac muscles when you work out (D) It keeps the level of carbon dioxide in the blood within a narrow range,A,"The organ systems of the body work together to carry out life processes and maintain homeostasis. The body is in homeostasis when its internal environment is kept more-or-less constant. For example, levels of sugar, carbon dioxide, and water in the blood must be kept within narrow ranges. This requires continuous adjustments. For example: After you eat and digest a sugary snack, the level of sugar in your blood quickly rises. In response, the endocrine system secretes the hormone insulin. Insulin helps cells absorb sugar from the blood. This causes the level of sugar in the blood to fall back to its normal level. When you work out on a hot day, you lose a lot of water through your skin in sweat. The level of water in the blood may fall too low. In response, the excretory system excretes less water in urine. Instead, the water is returned to the blood to keep water levels from falling lower. What happens if homeostasis is not maintained? Cells may not get everything they need, or toxic wastes may build up in the body. If homeostasis is not restored, it may cause illness or even death. "
What is the basic function of the circulatory system?,(A) transporting substances (B) taking in oxygen (C) controlling sensations (D) allowing movement,A,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
Type(s) of tissue found in the human heart and blood vessels include,(A) nervous tissue (B) epithelial tissue (C) connective tissue (D) all of the above,D,"Blood vessels are long, tube-like organs that consist mainly of muscle, connective, and epithelial tissues. They branch to form a complex network of vessels that run throughout the body. This network transports blood to all the bodys cells. "
The integumentary system includes the,(A) skin (B) nails (C) hair (D) all of the above,D,"Did you know that you see the largest organ in your body every day? You wash it, dry it, cover it up to stay warm, and uncover it to cool off. Yes, your skin is your bodys largest organ. Your skin is part of your integumentary system ( Figure 1.1), which is the outer covering of your body. The integumentary system is made up of your skin, hair, and nails. Skin acts as a barrier that stops water and other things, like soap and dirt, from getting into your body. "
Structures in the epidermis include,(A) sebaceous glands (B) hair follicles (C) melanocytes (D) all of the above,C,"The dermis is the inner layer of skin. It is made of tough connective tissue. The dermis is attached to the epidermis by fibers made of the protein collagen. The dermis is where most skin structures are located. Look again at Figure pain, pressure, and temperature. If you cut your skin and it bleeds, the cut has penetrated the dermis and damaged a blood vessel. The cut probably hurts as well because of the nerve endings in this skin layer. The dermis also contains hair follicles and two types of glands. You can see some of these structures in Figure 16.8. Hair follicles are structures where hairs originate. Each hair grows out of a follicle, passes up through the epidermis, and extends above the skin surface. Sebaceous glands are commonly called oil glands. They produce an oily substance called sebum. Sebum is secreted into hair follicles. Then it makes its way along the hair shaft to the surface of the skin. Sebum waterproofs the hair and skin and helps prevent them from drying out. Sweat glands produce the salty fluid known as sweat. Sweat contains excess water, salts, and other waste products. Each sweat gland has a duct that passes through the epidermis. Sweat travels from the gland through the duct and out through a pore on the surface of the skin. "
How does melanin protect the dermis from ultraviolet light?,(A) It reflects ultraviolet light (B) It absorbs ultraviolet light (C) It changes ultraviolet light to visible light (D) It changes ultraviolet light to vitamin D,B,"You couldnt survive without your skin. It has many important functions. In several ways, it helps maintain homeostasis. The main function of the skin is controlling what enters and leaves the body. It prevents the loss of too much water from the body. It also prevents bacteria and other microorganisms from entering the body. Melanin in the epidermis absorbs ultraviolet light. This prevents the light from reaching and damaging the dermis. The skin helps maintain a constant body temperature. It keeps the body cool in two ways. Sweat from sweat glands in the skin evaporates to cool the body. Blood vessels in the skin dilate, or widen, increasing blood flow to the body surface. This allows more heat to reach the surface and radiate into the environment. The opposite happens to retain body heat. Blood vessels in the skin constrict, or narrow, decreasing blood flow to the body surface. This reduces the amount of heat that reaches the surface so less heat is lost to the environment. "
The dermis consists mainly of,(A) epithelial tissue (B) muscle tissue (C) nervous tissue (D) connective tissue,D,"The dermis is the layer of skin directly under the epidermis. It is made of a tough connective tissue. The dermis contains hair follicles, sweat glands, oil glands, and blood vessels ( Figure 1.2). It also holds many nerve endings that give you your sense of touch, pressure, heat, and pain. Do you ever notice how your hair stands up when you are cold or afraid? Tiny muscles in the dermis pull on hair follicles which cause hair to stand up. The resulting little bumps in the skin are commonly called ""goosebumps"" ( Figure 1.3). "
Which structures are found in the lower layer of skin?,(A) nerve endings (B) blood vessels (C) sweat glands (D) all of the above,D,"The dermis is the inner layer of skin. It is made of tough connective tissue. The dermis is attached to the epidermis by fibers made of the protein collagen. The dermis is where most skin structures are located. Look again at Figure pain, pressure, and temperature. If you cut your skin and it bleeds, the cut has penetrated the dermis and damaged a blood vessel. The cut probably hurts as well because of the nerve endings in this skin layer. The dermis also contains hair follicles and two types of glands. You can see some of these structures in Figure 16.8. Hair follicles are structures where hairs originate. Each hair grows out of a follicle, passes up through the epidermis, and extends above the skin surface. Sebaceous glands are commonly called oil glands. They produce an oily substance called sebum. Sebum is secreted into hair follicles. Then it makes its way along the hair shaft to the surface of the skin. Sebum waterproofs the hair and skin and helps prevent them from drying out. Sweat glands produce the salty fluid known as sweat. Sweat contains excess water, salts, and other waste products. Each sweat gland has a duct that passes through the epidermis. Sweat travels from the gland through the duct and out through a pore on the surface of the skin. "
The human skin is about 2 centimeters thick.,(A) true (B) false,B,"From the outside, the skin looks plain and simple, as you can see in Figure 16.5. But at a cellular level, theres nothing plain or simple about it. A single square inch of skin contains about 20 blood vessels, hundreds of sweat glands, and more than a thousand nerve endings. It also contains tens of thousands of pigment-producing cells. Clearly, there is much more to skin than meets the eye! For a dramatic introduction to the skin, watch this video: MEDIA Click image to the left or use the URL below. URL:  The skin is only about 2 mm thick, or about as thick as the cover of a book. Although it is very thin, it consists of two distinct layers, called the epidermis and the dermis. You can see both layers and some of their structures in Figure 16.6. Refer to the figure as you read about the epidermis and dermis below. "
All the cells on the surface of the epidermis are dead.,(A) true (B) false,A,"The epidermis is the outer layer of skin. It consists almost entirely of epithelial cells. There are no blood vessels, nerve endings, or glands in this skin layer. Nonetheless, this layer of skin is very active. It is constantly being renewed. How does this happen? 1. The cells at the bottom of the epidermis are always dividing by mitosis to form new cells. 2. The new cells gradually move up through the epidermis toward the surface of the body. As they move, they produce the tough, fibrous protein called keratin. 3. By the time the cells reach the surface, they have filled with keratin and died. On the surface, the dead cells form a protective, waterproof layer. 4. Dead cells are gradually shed from the surface of the epidermis. As they are shed, they are replaced by other dead cells that move up from below. The epidermis also contains cells called melanocytes. You can see a melanocyte in Figure 16.7. Melanocytes produce melanin. Melanin is a brown pigment that gives skin much of its color. Everyones skin has about the same number of melanocytes per square inch. However, the melanocytes of people with darker skin produce more melanin. The amount of melanin that is produced depends partly on your genes and partly on how much ultraviolet light strikes your skin. The more light you get, the more melanin your melanocytes produce. This explains why skin tans when its exposed to sunlight. "
People with light skin have fewer melanocytes per square inch than people with dark skin.,(A) true (B) false,B,"From the outside, the skin looks plain and simple, as you can see in Figure 16.5. But at a cellular level, theres nothing plain or simple about it. A single square inch of skin contains about 20 blood vessels, hundreds of sweat glands, and more than a thousand nerve endings. It also contains tens of thousands of pigment-producing cells. Clearly, there is much more to skin than meets the eye! For a dramatic introduction to the skin, watch this video: MEDIA Click image to the left or use the URL below. URL:  The skin is only about 2 mm thick, or about as thick as the cover of a book. Although it is very thin, it consists of two distinct layers, called the epidermis and the dermis. You can see both layers and some of their structures in Figure 16.6. Refer to the figure as you read about the epidermis and dermis below. "
The production of melanin in the skin is stimulated by exposure to ultraviolet light.,(A) true (B) false,A,"Some sunlight is good for your health. Vitamin D is made in the skin when it is exposed to sunlight. But getting too much sun can be unhealthy. A sunburn is a burn to the skin that is caused by overexposure to UV radiation from the suns rays or tanning beds. Light-skinned people, like the man pictured below ( Figure 1.1), get sunburned more quickly than people with darker skin. This is because pigments (melanin) in the skin act as a natural sunblock that help to protect the body from UV radiation. With over one million new cases each year, skin cancer, which is cancer that forms in the tissues of the skin, is the most common form of human cancer. Children and teens who have been sunburned are at a greater risk of developing skin cancer later in life. Long-term exposure to UV radiation is the leading cause of skin cancer. About 90 percent of skin cancers are linked to sun exposure. UV radiation damages the genetic material (DNA) of skin cells. This damage can cause the skin cells to grow out of control and form a tumor. Some of these tumors are very difficult to cure. For this reason you should always wear sunscreen with a high sun protection factor (SPF), a hat, and clothing when out in the sun. Sunburn is caused by overexposure to UV rays. Getting sunburned as a child or a teen, especially sunburn that causes blistering, increases the risk of developing skin cancer later in life. "
The function of sebum is to waterproof the hair and skin.,(A) true (B) false,A,"Glands and hair follicles open out into the epidermis, but they start in the dermis. Oil glands ( Figure 1.2) release, or secrete an oily substance, called sebum, into the hair follicle. Sebum waterproofs hair and the skin surface to prevent them from drying out. It can also stop the growth of bacteria on the skin. It is odorless, but the breakdown of sebum by bacteria can cause odors. If an oil gland becomes plugged and infected, it develops into a pimple. Up to 85% of teenagers get pimples, which usually go away by adulthood. Frequent washing can help decrease the amount of sebum on the skin. Sweat glands ( Figure 1.2) open to the skin surface through skin pores. They are found all over the body. Evaporation of sweat from the skin surface helps to lower skin temperature. The skin also releases excess water, salts, sugars, and other wastes, such as ammonia and urea, in sweat. The Integumentary System Song can be heard at  . Goosebumps are caused by tiny mus- cles in the dermis that pull on hair folli- cles, which causes the hairs to stand up straight. "
The skin helps maintain homeostasis by regulating body temperature.,(A) true (B) false,A,"The skin has many important functions. The skin: Provides a barrier. It keeps organisms that could harm the body out. It stops water from entering or leaving the body. Controls body temperature. It does this by making sweat (or perspiration), a watery substance that cools the body when it evaporates. Gathers information about your environment. Special nerve endings in your skin sense heat, pressure, cold, and pain. Helps the body get rid of some types of waste, which are removed in sweat. Acts as a sun block. A pigment called melanin blocks sunlight from getting to deeper layers of skin cells, which are easily damaged by sunlight. "
Sweat contains only water and salt.,(A) true (B) false,B,"Have you ever gone swimming in the ocean? If you have, then you probably tasted the salts in the water. By mass, salts make up about 3.5 percent of ocean water. Figure 14.5 shows the most common minerals in ocean water. The main components are sodium and chloride. Together they form the salt known as sodium chloride. You may know the compound as table salt or the mineral halite. The amount of salts in ocean water varies from place to place. For example, near the mouth of a river, ocean water may be less salty. Thats because river water contains less salt than ocean water. Where the ocean is warm, the water may be more salty. Can you explain why? (Hint: More water evaporates when the water is warm.) "
_____The main cause of acne is eating greasy foods.,(A) true (B) false,B,"What can you do to keep your skin healthy? The most important step you can take is to protect your skin from sun exposure. On sunny days, wear long sleeves and pants and a hat with a brim. Also apply sunscreen to exposed areas of skin. Protecting your skin in these ways will reduce damage to your skin by ultraviolet light. This is important because skin that has been damaged by ultraviolet light is at greater risk of developing skin cancer. This is true whether the damage is due to sunlight or the light in tanning beds. About 85 percent of teens develop acne, like the boy in Figure 16.9. Acne is a condition in which pimples form on the skin. It is caused by a bacterial infection. It happens when the sebaceous glands secrete too much sebum. The excess oil provides a good place for bacteria to grow. Keeping the skin clean helps prevent acne. Over-the-counter products or prescription drugs may be needed if the problem is serious or doesnt clear up on its own. "
"When blood vessels in the skin dilate, more heat reaches the body surface.",(A) true (B) false,A,"Blood vessels help regulate body processes by either dilating (widening) or constricting (narrowing). This changes the amount of blood flowing to particular organs. For example, dilation of blood vessels in the skin allows more blood to flow to the surface of the body. This helps the body lose excess heat. Constriction of these blood vessels has the opposite effect and helps the body conserve heat. "
Skin damaged by ultraviolet light is at greater risk of developing cancer.,(A) true (B) false,A,"Some sunlight is good for your health. Vitamin D is made in the skin when it is exposed to sunlight. But getting too much sun can be unhealthy. A sunburn is a burn to the skin that is caused by overexposure to UV radiation from the suns rays or tanning beds. Light-skinned people, like the man pictured below ( Figure 1.1), get sunburned more quickly than people with darker skin. This is because pigments (melanin) in the skin act as a natural sunblock that help to protect the body from UV radiation. With over one million new cases each year, skin cancer, which is cancer that forms in the tissues of the skin, is the most common form of human cancer. Children and teens who have been sunburned are at a greater risk of developing skin cancer later in life. Long-term exposure to UV radiation is the leading cause of skin cancer. About 90 percent of skin cancers are linked to sun exposure. UV radiation damages the genetic material (DNA) of skin cells. This damage can cause the skin cells to grow out of control and form a tumor. Some of these tumors are very difficult to cure. For this reason you should always wear sunscreen with a high sun protection factor (SPF), a hat, and clothing when out in the sun. Sunburn is caused by overexposure to UV rays. Getting sunburned as a child or a teen, especially sunburn that causes blistering, increases the risk of developing skin cancer later in life. "
Hair grows longer because it is made up of living cells.,(A) true (B) false,B,"Hair is one of the defining characteristics of mammals. In fact, mammals are the only animals to have hair. Hair sticks out from the epidermis, but it grows from the dermis ( Figure 1.1). Hair grows from inside the hair follicle. New cells grow in the bottom part of the hair, called the bulb. Older cells get pushed up, and the hair grows longer. The cells that make up the hair strand are dead and filled with the rope-like protein keratin. Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water loss from the skin. The sebaceous gland secretes sebum, which waterproofs the skin and hair. In humans, hair grows everywhere on the body except the soles of the feet and the palms of the hands, the lips, and the eyelids (except for eyelashes). Hair grows at a rate of about half an inch (1.25 cm) each month, or about 6 inches (15 cm) a year. Hair, especially on the head, helps to keep the body warm. The air traps a layer of warm air near the skin and acts like a warm blanket. Hair can also act as a filter. Nose hair helps to trap particles in the air that may otherwise travel to the lungs. Eyelashes shield eyes from dust and sunlight. Eyebrows stop salty sweat and rain from flowing into the eye. The worlds longest documented hair, according to Guinness World Records, belongs to Xie Qiuping of China at just under 18 feet 6 inches (5.627 m) when measured on May 8, 2004. She had been growing her hair since 1973 when she was 13 years old. "
Sweat reaches the surface of the skin by traveling through hair follicles.,(A) true (B) false,B,"Glands and hair follicles open out into the epidermis, but they start in the dermis. Oil glands ( Figure 1.2) release, or secrete an oily substance, called sebum, into the hair follicle. Sebum waterproofs hair and the skin surface to prevent them from drying out. It can also stop the growth of bacteria on the skin. It is odorless, but the breakdown of sebum by bacteria can cause odors. If an oil gland becomes plugged and infected, it develops into a pimple. Up to 85% of teenagers get pimples, which usually go away by adulthood. Frequent washing can help decrease the amount of sebum on the skin. Sweat glands ( Figure 1.2) open to the skin surface through skin pores. They are found all over the body. Evaporation of sweat from the skin surface helps to lower skin temperature. The skin also releases excess water, salts, sugars, and other wastes, such as ammonia and urea, in sweat. The Integumentary System Song can be heard at  . Goosebumps are caused by tiny mus- cles in the dermis that pull on hair folli- cles, which causes the hairs to stand up straight. "
__outer layer of the skin,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,E,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
__tough protein that fills hair cells,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,F,"Only mammals have hair. Hair is a fiber made mainly of the tough protein keratin. The cells of each hair are filled with keratin and no longer alive. The dead cells overlap each other, almost like shingles on a roof. They work like shingles as well, by helping shed water from hair. Head hair helps protect the scalp from sun exposure. It also helps insulate the body. It traps air so heat cant escape from the head. Hair in eyelashes and eyebrows helps keep water and dust out of the eyes. Hairs inside the nostrils of the nose trap dust and germs in the air so they cant reach the lungs. "
__skin structure where a hair originates,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,B,"The dermis is the inner layer of skin. It is made of tough connective tissue. The dermis is attached to the epidermis by fibers made of the protein collagen. The dermis is where most skin structures are located. Look again at Figure pain, pressure, and temperature. If you cut your skin and it bleeds, the cut has penetrated the dermis and damaged a blood vessel. The cut probably hurts as well because of the nerve endings in this skin layer. The dermis also contains hair follicles and two types of glands. You can see some of these structures in Figure 16.8. Hair follicles are structures where hairs originate. Each hair grows out of a follicle, passes up through the epidermis, and extends above the skin surface. Sebaceous glands are commonly called oil glands. They produce an oily substance called sebum. Sebum is secreted into hair follicles. Then it makes its way along the hair shaft to the surface of the skin. Sebum waterproofs the hair and skin and helps prevent them from drying out. Sweat glands produce the salty fluid known as sweat. Sweat contains excess water, salts, and other waste products. Each sweat gland has a duct that passes through the epidermis. Sweat travels from the gland through the duct and out through a pore on the surface of the skin. "
__major organ of the integumentary system,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,G,"Did you know that you see the largest organ in your body every day? You wash it, dry it, cover it up to stay warm, and uncover it to cool off. Yes, your skin is your bodys largest organ. Your skin is part of your integumentary system ( Figure 1.1), which is the outer covering of your body. The integumentary system is made up of your skin, hair, and nails. Skin acts as a barrier that stops water and other things, like soap and dirt, from getting into your body. "
__oily substance secreted by glands in the skin,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,C,"Glands and hair follicles open out into the epidermis, but they start in the dermis. Oil glands ( Figure 1.2) release, or secrete an oily substance, called sebum, into the hair follicle. Sebum waterproofs hair and the skin surface to prevent them from drying out. It can also stop the growth of bacteria on the skin. It is odorless, but the breakdown of sebum by bacteria can cause odors. If an oil gland becomes plugged and infected, it develops into a pimple. Up to 85% of teenagers get pimples, which usually go away by adulthood. Frequent washing can help decrease the amount of sebum on the skin. Sweat glands ( Figure 1.2) open to the skin surface through skin pores. They are found all over the body. Evaporation of sweat from the skin surface helps to lower skin temperature. The skin also releases excess water, salts, sugars, and other wastes, such as ammonia and urea, in sweat. The Integumentary System Song can be heard at  . Goosebumps are caused by tiny mus- cles in the dermis that pull on hair folli- cles, which causes the hairs to stand up straight. "
__inner layer of the skin,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,D,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
__type of cell that produces a brown pigment in skin,(A) amelanocyte (B) bfollicle (C) csebum (D) ddermis (E) eepidermis (F) fkeratin (G) gskin,A,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
Functions of the integumentary system include,(A) maintaining a stable body temperature (B) preventing the body from drying out (C) keeping bacteria out of the body (D) all of the above,D,"The skin has many important functions. The skin: Provides a barrier. It keeps organisms that could harm the body out. It stops water from entering or leaving the body. Controls body temperature. It does this by making sweat (or perspiration), a watery substance that cools the body when it evaporates. Gathers information about your environment. Special nerve endings in your skin sense heat, pressure, cold, and pain. Helps the body get rid of some types of waste, which are removed in sweat. Acts as a sun block. A pigment called melanin blocks sunlight from getting to deeper layers of skin cells, which are easily damaged by sunlight. "
The outer layer of the skin contains,(A) blood vessels (B) nerve endings (C) sweat glands (D) melanocytes,D,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
The epidermis consists almost entirely of,(A) epithelial tissue (B) connective tissue (C) muscle tissue (D) nervous tissue,A,"The epidermis is the outer layer of skin. It consists almost entirely of epithelial cells. There are no blood vessels, nerve endings, or glands in this skin layer. Nonetheless, this layer of skin is very active. It is constantly being renewed. How does this happen? 1. The cells at the bottom of the epidermis are always dividing by mitosis to form new cells. 2. The new cells gradually move up through the epidermis toward the surface of the body. As they move, they produce the tough, fibrous protein called keratin. 3. By the time the cells reach the surface, they have filled with keratin and died. On the surface, the dead cells form a protective, waterproof layer. 4. Dead cells are gradually shed from the surface of the epidermis. As they are shed, they are replaced by other dead cells that move up from below. The epidermis also contains cells called melanocytes. You can see a melanocyte in Figure 16.7. Melanocytes produce melanin. Melanin is a brown pigment that gives skin much of its color. Everyones skin has about the same number of melanocytes per square inch. However, the melanocytes of people with darker skin produce more melanin. The amount of melanin that is produced depends partly on your genes and partly on how much ultraviolet light strikes your skin. The more light you get, the more melanin your melanocytes produce. This explains why skin tans when its exposed to sunlight. "
The dermis is attached to the epidermis by,(A) collagen fibers (B) muscle fibers (C) keratin fibers (D) nerve fibers,A,"The dermis is the layer of skin directly under the epidermis. It is made of a tough connective tissue. The dermis contains hair follicles, sweat glands, oil glands, and blood vessels ( Figure 1.2). It also holds many nerve endings that give you your sense of touch, pressure, heat, and pain. Do you ever notice how your hair stands up when you are cold or afraid? Tiny muscles in the dermis pull on hair follicles which cause hair to stand up. The resulting little bumps in the skin are commonly called ""goosebumps"" ( Figure 1.3). "
What is the function of sebum?,(A) keeping the body cool (B) absorbing ultraviolet light (C) waterproofing the hair and skin (D) none of the above,C,"Glands and hair follicles open out into the epidermis, but they start in the dermis. Oil glands ( Figure 1.2) release, or secrete an oily substance, called sebum, into the hair follicle. Sebum waterproofs hair and the skin surface to prevent them from drying out. It can also stop the growth of bacteria on the skin. It is odorless, but the breakdown of sebum by bacteria can cause odors. If an oil gland becomes plugged and infected, it develops into a pimple. Up to 85% of teenagers get pimples, which usually go away by adulthood. Frequent washing can help decrease the amount of sebum on the skin. Sweat glands ( Figure 1.2) open to the skin surface through skin pores. They are found all over the body. Evaporation of sweat from the skin surface helps to lower skin temperature. The skin also releases excess water, salts, sugars, and other wastes, such as ammonia and urea, in sweat. The Integumentary System Song can be heard at  . Goosebumps are caused by tiny mus- cles in the dermis that pull on hair folli- cles, which causes the hairs to stand up straight. "
The major cause of acne is,(A) exposure to sunlight (B) infection by bacteria (C) overproduction of sweat (D) lack of sleep,B,"What can you do to keep your skin healthy? The most important step you can take is to protect your skin from sun exposure. On sunny days, wear long sleeves and pants and a hat with a brim. Also apply sunscreen to exposed areas of skin. Protecting your skin in these ways will reduce damage to your skin by ultraviolet light. This is important because skin that has been damaged by ultraviolet light is at greater risk of developing skin cancer. This is true whether the damage is due to sunlight or the light in tanning beds. About 85 percent of teens develop acne, like the boy in Figure 16.9. Acne is a condition in which pimples form on the skin. It is caused by a bacterial infection. It happens when the sebaceous glands secrete too much sebum. The excess oil provides a good place for bacteria to grow. Keeping the skin clean helps prevent acne. Over-the-counter products or prescription drugs may be needed if the problem is serious or doesnt clear up on its own. "
The dermis contains all of the following except,(A) sebaceous glands (B) hair follicles (C) melanin-producing cells (D) sweat glands,C,"The dermis is the layer of skin directly under the epidermis. It is made of a tough connective tissue. The dermis contains hair follicles, sweat glands, oil glands, and blood vessels ( Figure 1.2). It also holds many nerve endings that give you your sense of touch, pressure, heat, and pain. Do you ever notice how your hair stands up when you are cold or afraid? Tiny muscles in the dermis pull on hair follicles which cause hair to stand up. The resulting little bumps in the skin are commonly called ""goosebumps"" ( Figure 1.3). "
Components of the skeletal system include,(A) bones (B) cartilage (C) ligaments (D) all of the above,D,"Your skeletal system gives shape and form to your body, but it also plays other important roles. The main functions of the skeletal system include: The skeletal system is made up of bones, cartilage, and ligaments. The skeletal system has many important functions in your body. What bones protect the heart and lungs? What protects the brain? Support. The skeleton supports the body against the pull of gravity, meaning you dont fall over when you stand up. The large bones of the lower limbs support the rest of the body when standing. Protection. The skeleton supports and protects the soft organs of the body. For example, the skull surrounds the brain to protect it from injury. The bones of the rib cage help protect the heart and lungs. Movement. Bones work together with muscles to move the body. Making blood cells. Blood cells are mostly made inside certain types of bones. "
The adult skeleton consists of,(A) 56 bones (B) 76 bones (C) 106 bones (D) 206 bones,D,"Bones are the main organs of the skeletal system. In adults, the skeleton consists of a whopping 206 bones, many of them in the hands and feet. You can see many of the bones of the human skeleton in Figure 16.10. The skeletal system also includes cartilage and ligaments. Cartilage is a tough, flexible connective tissue that contains the protein collagen. It covers the ends of bones where they meet. The gray tissue in Figure 16.10 is cartilage. A ligament is a band of fibrous connective tissue. Ligaments connect bones of the skeleton and hold them together. "
Functions of the skeletal system include,(A) making blood cells (B) storing calcium (C) giving the body shape (D) all of the above,D,"Your skeletal system gives shape and form to your body, but it also plays other important roles. The main functions of the skeletal system include: The skeletal system is made up of bones, cartilage, and ligaments. The skeletal system has many important functions in your body. What bones protect the heart and lungs? What protects the brain? Support. The skeleton supports the body against the pull of gravity, meaning you dont fall over when you stand up. The large bones of the lower limbs support the rest of the body when standing. Protection. The skeleton supports and protects the soft organs of the body. For example, the skull surrounds the brain to protect it from injury. The bones of the rib cage help protect the heart and lungs. Movement. Bones work together with muscles to move the body. Making blood cells. Blood cells are mostly made inside certain types of bones. "
"Cartilage is a tough, flexible tissue that contains the protein",(A) keratin (B) cuticle (C) collagen (D) periosteum,C,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
Blood cells are produced by,(A) bone marrow (B) compact bone (C) spongy bone (D) cartilage,A,"Blood cancers affect the production and function of your blood cells. Most of these cancers start in your bone marrow where blood is produced. In most blood cancers, the normal production of blood cells is replaced by uncontrolled growth of an abnormal type of blood cell. These abnormal blood cells are cancerous cells, and prevent your blood from performing many of its functions, like fighting off infections or preventing serious bleeding. Leukemia is a cancer of the blood or bone marrow. It is characterized by an abnormal production of blood cells, usually white blood cells. Lymphoma is a cancer of a type of white blood cell called lymphocytes. There are many types of lymphoma. "
Which type of tissue gives bones their strength?,(A) periosteum (B) compact bone (C) spongy bone (D) bone marrow,B,"Bones are organs. Like other organs, they are made up of more than one kind of tissue. There are four different kinds of tissues in bones, as shown in Figure 16.11. From the outside of the bone to the center, the tissues are periosteum, compact bone, spongy bone, and bone marrow. Periosteum is a tough, fibrous membrane that covers and protects the outer surfaces of bone. Compact bone lies below periosteum. It is very dense and hard. Compact bone gives bones their strength. Spongy bone lies below compact bone. It is less dense than compact bone. Spongy bone contains many tiny holes, or pores, which provide spaces for blood vessels and bone marrow. Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells. "
Immovable joints connect the bones of the,(A) rib cage (B) shoulder (C) skull (D) none of the above,C,"A joint is a point at which two or more bones meet. There are three main types of joints in the body: 1. Fixed joints do not allow any bone movement. Many of the joints in your skull are fixed ( Figure 1.1). There are eight bones that fuse together to form the cranium. The joints between these bones do not allow movement, which helps protect the brain. 2. Partly movable joints allow only a little movement. Your backbone has partly movable joints between the vertebrae ( Figure 1.2). The skull has fixed joints. Fixed joints do not allow any movement of the bones, which protects the brain from injury. 3. Movable joints allow the most movement. Movable joints are also the most common type of joint in your body. Your fingers, toes, hips, elbows, and knees all provide examples of movable joints. The surfaces of bones at movable joints are covered with a smooth layer of cartilage. The cartilage reduces friction between the bones. Ligaments often cross a joint, holding two nones together. For example, there are numerous ligaments connecting the leg bones across the knee joint. "
Why do the ends of long bones ossify later than other parts of the skeleton?,(A) to cushion the ends of the bones (B) to prevent growing pains in the bones (C) to allow the bones to grow in width (D) to allow the bones to grow in length,D,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
Partly movable joints are held together by,(A) collagen (B) keratin (C) cartilage (D) ligaments,C,"A joint is a place where two or more bones of the skeleton meet. There are three different types of joints based on the degree to which they allow movement of the bones: immovable, partly movable, and movable joints. Immovable joints do not allow the bones to move at all. In these joints, the bones are fused together by very tough collagen. Examples of immovable joints include the joints between bones of the skull. You can see them in Figure 16.12. Partly movable joints allow very limited movement. In these joints, the bones are held together by cartilage, which is more flexible than collagen. Examples of partly moveable joints include the bones of the rib cage. Movable joints allow the greatest movement and are the most common. In these joints, the bones are connected by ligaments. The surfaces of the bones at the joints are covered with a smooth layer of cartilage. It reduces friction between the bones when they move. The space between the bones is also filled with a liquid called synovial fluid. It helps to cushion the bones. There are several different types of movable joints. You can see three of them in Figure 16.13. Move these three joints in your own skeleton to experience the range of motion each allows. "
Which bones are connected by partly movable joints?,(A) bones of the skull (B) bones of the ribcage (C) bones of the arms (D) bones of the legs,B,"A joint is a point at which two or more bones meet. There are three main types of joints in the body: 1. Fixed joints do not allow any bone movement. Many of the joints in your skull are fixed ( Figure 1.1). There are eight bones that fuse together to form the cranium. The joints between these bones do not allow movement, which helps protect the brain. 2. Partly movable joints allow only a little movement. Your backbone has partly movable joints between the vertebrae ( Figure 1.2). The skull has fixed joints. Fixed joints do not allow any movement of the bones, which protects the brain from injury. 3. Movable joints allow the most movement. Movable joints are also the most common type of joint in your body. Your fingers, toes, hips, elbows, and knees all provide examples of movable joints. The surfaces of bones at movable joints are covered with a smooth layer of cartilage. The cartilage reduces friction between the bones. Ligaments often cross a joint, holding two nones together. For example, there are numerous ligaments connecting the leg bones across the knee joint. "
Which joint moves like the hinge on a door?,(A) shoulder (B) elbow (C) knee (D) back,C,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
Which statement about bone fractures is false?,(A) Bone fractures naturally heal on their own (B) Bone fractures are caused by excess stress on bone (C) People with osteoporosis have an increased risk of bone fractures (D) none of the above,D,"People with osteoporosis have an increased risk of bone fractures. A bone fracture is a crack or break in bone. Even if you have healthy bones, you may fracture a bone if too much stress is placed on it. This could happen in a car crash or while playing a sport. Wearing a seatbelt when you ride in a motor vehicle and wearing safety gear when you play sports may help prevent bone fractures. Bone fractures heal naturally as new bone tissue forms at the site of the fracture. However, the bone may have to be placed in a cast or have rods or screws inserted into it to keep it correctly aligned until it heals. The healing process usually takes several weeks or even months. "
Bones release stored calcium to the blood as needed.,(A) true (B) false,A,"Your skeletal system supports your body and gives it shape. What else does it do? The skeletal system makes blood cells. Most blood cells are produced inside certain types of bones. The skeletal system stores calcium and helps maintain normal levels of calcium in the blood. Bones take up and store calcium when blood levels of calcium are high. They release some of the stored calcium when blood levels of calcium are low. The skeletal system works with muscles to move the body. Try to walk without bending your knees and youll see how important the skeletal system is for movement. The skeletal system protects the soft organs of the body. For example, the skull surrounds and protects the brain. The ribs protect the heart and lungs. "
"Bones are like chalk: dead, dry, and brittle.",(A) true (B) false,B,"Some people think bones are like chalk: dead, dry, and brittle. In reality, bones are very much alive. They consist of living tissues and are supplied with blood and nerves. "
Bones are organs made up of four types of bone tissues.,(A) true (B) false,A,"Bones come in many different shapes and sizes, but they are all made of the same materials. Bones are organs, and recall that organs are made up of two or more types of tissues. The two main types of bone tissue are compact bone and spongy bone ( Figure 1.2). Compact bone makes up the dense outer layer of bones. Spongy bone is found at the center of the bone and is lighter and more porous than compact bone. Bones look tough, shiny, and white because they are covered by a layer called the periosteum. Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Bones are made up of different types of tissues. "
Compact bone lies between spongy bone and periosteum.,(A) true (B) false,A,"Bones are organs. Like other organs, they are made up of more than one kind of tissue. There are four different kinds of tissues in bones, as shown in Figure 16.11. From the outside of the bone to the center, the tissues are periosteum, compact bone, spongy bone, and bone marrow. Periosteum is a tough, fibrous membrane that covers and protects the outer surfaces of bone. Compact bone lies below periosteum. It is very dense and hard. Compact bone gives bones their strength. Spongy bone lies below compact bone. It is less dense than compact bone. Spongy bone contains many tiny holes, or pores, which provide spaces for blood vessels and bone marrow. Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells. "
An example of a ball-and-socket joint is the elbow.,(A) true (B) false,B,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
Calcium and vitamin D are needed to keep bones strong.,(A) true (B) false,A,"Did you know that what you eat as a teenager can affect how healthy your skeletal system will be in 30, 40, and even 50 years? Calcium and vitamin D are two of the most important nutrients for a healthy skeletal system. Your bones need calcium to grow properly. If you do not get enough calcium in your diet as a teenager, your bones may become weak and break easily later in life. Osteoporosis is a disease in which bones lose mass and become more fragile than they should be. Osteoporosis also makes bones more likely to break. Two of the easiest ways to prevent osteoporosis are eating a healthy diet that has the right amount of calcium and vitamin D and to do some sort of weight-bearing exercise every day. Foods that are a good source of calcium include milk, yogurt, and cheese. Non-dairy sources of calcium include Chinese cabbage, kale, and broccoli. Many fruit juices, fruit drinks, tofu, and cereals have calcium added to them. It is recommended that teenagers get 1300 mg of calcium every day. For example, one cup (8 fl. oz.) of milk provides about 300 mg of calcium, or about 30% of the daily requirement. Other sources of calcium are pictured in the Figure 1.1. There are many different sources of cal- cium. Getting enough calcium in your daily diet is important for good bone health. Vitamin D is unusual since you dont have to rely on your diet alone to get enough of this vitamin. Your skin makes vitamin D when exposed to sunlight. Pigments in the skin act like a filter that can prevent the skin from making vitamin D. As a result, people with darker skin need more time in the sun than people with lighter skin to make the same amount of vitamin D. You can also get vitamin D from foods. Fish is naturally rich in vitamin D. In the United States, vitamin D is added to other foods, including milk, soy milk, and breakfast cereals. Teenagers are recommended to get 5 micrograms (200 IU) of vitamin D every day. A 3 12 -ounce portion of cooked salmon provides 360 IU of vitamin D. A 8-ounce glass of milk is fortified with about 100 IU of vitamin D. "
Blood cells are produced by compact bone.,(A) true (B) false,B,"Bones come in many different shapes and sizes, but they are all made of the same materials. Bones are organs, and recall that organs are made up of two or more types of tissues. The two main types of bone tissue are compact bone and spongy bone ( Figure 1.2). Compact bone makes up the dense outer layer of bones. Spongy bone is found at the center of the bone and is lighter and more porous than compact bone. Bones look tough, shiny, and white because they are covered by a layer called the periosteum. Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Bones are made up of different types of tissues. "
People with osteoporosis have an increased risk of bone fractures.,(A) true (B) false,A,"People with osteoporosis have an increased risk of bone fractures. A bone fracture is a crack or break in bone. Even if you have healthy bones, you may fracture a bone if too much stress is placed on it. This could happen in a car crash or while playing a sport. Wearing a seatbelt when you ride in a motor vehicle and wearing safety gear when you play sports may help prevent bone fractures. Bone fractures heal naturally as new bone tissue forms at the site of the fracture. However, the bone may have to be placed in a cast or have rods or screws inserted into it to keep it correctly aligned until it heals. The healing process usually takes several weeks or even months. "
"By birth, the human skeleton consists entirely of bone.",(A) true (B) false,B,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
Bones grow thicker when they are put under stress by muscles.,(A) true (B) false,A,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
A sprain occurs when a bone bends but doesnt break.,(A) true (B) false,B,"Another type of skeletal system injury is a sprain. A sprain is a strain or tear in a ligament that has been twisted or stretched too far. Ankle sprains are a common type of sprain. Athletes often strain a ligament in the knee called the ACL. Warming up adequately and stretching before playing sports may reduce the risk of a sprain. Ligament injuries can take a long time to heal. Rest, ice, compression, and elevation of the sprained area may help the healing process. "
The adult skeletal system contains 206 bones.,(A) true (B) false,A,"Bones are the main organs of the skeletal system. In adults, the skeleton consists of a whopping 206 bones, many of them in the hands and feet. You can see many of the bones of the human skeleton in Figure 16.10. The skeletal system also includes cartilage and ligaments. Cartilage is a tough, flexible connective tissue that contains the protein collagen. It covers the ends of bones where they meet. The gray tissue in Figure 16.10 is cartilage. A ligament is a band of fibrous connective tissue. Ligaments connect bones of the skeleton and hold them together. "
__type of bone tissue that contains many tiny pores,(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,D,"Bones are organs. Like other organs, they are made up of more than one kind of tissue. There are four different kinds of tissues in bones, as shown in Figure 16.11. From the outside of the bone to the center, the tissues are periosteum, compact bone, spongy bone, and bone marrow. Periosteum is a tough, fibrous membrane that covers and protects the outer surfaces of bone. Compact bone lies below periosteum. It is very dense and hard. Compact bone gives bones their strength. Spongy bone lies below compact bone. It is less dense than compact bone. Spongy bone contains many tiny holes, or pores, which provide spaces for blood vessels and bone marrow. Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells. "
"__tough, fibrous tissue that forms the outer layer of bone",(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,E,"Bones are organs. Like other organs, they are made up of more than one kind of tissue. There are four different kinds of tissues in bones, as shown in Figure 16.11. From the outside of the bone to the center, the tissues are periosteum, compact bone, spongy bone, and bone marrow. Periosteum is a tough, fibrous membrane that covers and protects the outer surfaces of bone. Compact bone lies below periosteum. It is very dense and hard. Compact bone gives bones their strength. Spongy bone lies below compact bone. It is less dense than compact bone. Spongy bone contains many tiny holes, or pores, which provide spaces for blood vessels and bone marrow. Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells. "
__type of bone tissue that is very dense and hard,(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,A,"Bones come in many different shapes and sizes, but they are all made of the same materials. Bones are organs, and recall that organs are made up of two or more types of tissues. The two main types of bone tissue are compact bone and spongy bone ( Figure 1.2). Compact bone makes up the dense outer layer of bones. Spongy bone is found at the center of the bone and is lighter and more porous than compact bone. Bones look tough, shiny, and white because they are covered by a layer called the periosteum. Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Bones are made up of different types of tissues. "
__band of fibrous tissue that holds bones together,(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,F,"Bones are the main organs of the skeletal system. In adults, the skeleton consists of a whopping 206 bones, many of them in the hands and feet. You can see many of the bones of the human skeleton in Figure 16.10. The skeletal system also includes cartilage and ligaments. Cartilage is a tough, flexible connective tissue that contains the protein collagen. It covers the ends of bones where they meet. The gray tissue in Figure 16.10 is cartilage. A ligament is a band of fibrous connective tissue. Ligaments connect bones of the skeleton and hold them together. "
__soft tissue inside spongy bone that makes blood cells,(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,G,"Bones are organs. Like other organs, they are made up of more than one kind of tissue. There are four different kinds of tissues in bones, as shown in Figure 16.11. From the outside of the bone to the center, the tissues are periosteum, compact bone, spongy bone, and bone marrow. Periosteum is a tough, fibrous membrane that covers and protects the outer surfaces of bone. Compact bone lies below periosteum. It is very dense and hard. Compact bone gives bones their strength. Spongy bone lies below compact bone. It is less dense than compact bone. Spongy bone contains many tiny holes, or pores, which provide spaces for blood vessels and bone marrow. Bone marrow is a soft connective tissue inside pores and cavities in spongy bone. Bone marrow makes blood cells. "
"__tough, flexible connective tissue containing collagen",(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,C,"Bones are the main organs of the skeletal system. In adults, the skeleton consists of a whopping 206 bones, many of them in the hands and feet. You can see many of the bones of the human skeleton in Figure 16.10. The skeletal system also includes cartilage and ligaments. Cartilage is a tough, flexible connective tissue that contains the protein collagen. It covers the ends of bones where they meet. The gray tissue in Figure 16.10 is cartilage. A ligament is a band of fibrous connective tissue. Ligaments connect bones of the skeleton and hold them together. "
__process in which cartilage changes to bone,(A) acompact bone (B) bossification (C) ccartilage (D) dspongy bone (E) eperiosteum (F) fligament (G) gbone marrow,B,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
"To straighten your arm at the elbow, you would contract the",(A) quadriceps muscle (B) biceps muscle (C) triceps muscle (D) elbow muscle,C,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
__organelle that allows muscles to contract,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,F,"Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils. Myofibrils allow muscles to contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. "
__muscle found in the walls of internal organs except the heart,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,C,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
Smooth muscle is,(A) arranged in bundles (B) striped (C) involuntary (D) two of the above,C,"Smooth muscles and cardiac muscles are not attached to bone. Recall that these types of muscles are under involuntary control. Smooth muscle is responsible for the contractility of hollow organs, such as blood vessels, the gastrointestinal tract, the bladder, or the uterus. Like skeletal muscles, smooth muscle fibers do contract together, causing the muscle to shorten. Smooth muscles have numerous functions, including the following. The smooth muscle in the uterus helps a woman to push out her baby. In the bladder, smooth muscle helps to push out urine. Smooth muscles move food through the digestive tract. In arteries, smooth muscle movements maintain the arteries diameter. Smooth muscle regulates air flow in lungs. Smooth muscle in the lungs helps the airways to expand and contract as necessary. Smooth muscles in arteries and veins are largely responsible for regulation of blood pressure. Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. If your heart beats 75 times a minute, how many times does it beat in an hour? A day? A year? 85 years? "
The energy for a muscle contraction comes from,(A) actin (B) myosin (C) ATP (D) myofibrils,C,"To understand how a muscle contracts, you need to dive deeper into the structure of muscle fibers. You can see in Figure 16.16 that a muscle fiber is full of myofibrils. Each myofibril is made up of two types of proteins, called actin and myosin. These proteins form thread-like filaments. The myosin filaments use energy from ATP to pull on the actin filaments. This causes the actin filaments to slide over the myosin filaments and shorten a section of the myofibril. You can see a simple animation of the process at this link: http://commons.wikimedia.org/wiki/File:Actin_Myosin.gif The sliding-and-shortening process occurs all along many myofibrils and in many muscle fibers. It causes the muscle fibers to shorten and the muscle to contract. "
__tough connective tissue that attaches muscle to bone,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,E,"You can see the bundles of muscle fibers that make up a skeletal muscle in Figure 16.19. You can also see in the figure how the muscle is attached to a bone by a tendon. Tendons are tough connective tissues that anchor skeletal muscles to bones throughout the body. Many skeletal muscles are attached to the ends of bones where they meet at a joint. The muscles span the joint and connect the bones. When the muscles contract, they pull on the bones, causing them to move. "
"__long, thin muscle cell",(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,D,"Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils. Myofibrils allow muscles to contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. "
Which statement about cardiac muscle is false?,(A) It causes the heart to beat (B) It is under conscious control (C) It is striated muscle (D) none of the above,B,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
__muscle found in the walls of the heart,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,B,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
Skeletal muscles are attached to bones by,(A) ligaments (B) cartilage (C) muscle fibers (D) tendons,D,"You can see the bundles of muscle fibers that make up a skeletal muscle in Figure 16.19. You can also see in the figure how the muscle is attached to a bone by a tendon. Tendons are tough connective tissues that anchor skeletal muscles to bones throughout the body. Many skeletal muscles are attached to the ends of bones where they meet at a joint. The muscles span the joint and connect the bones. When the muscles contract, they pull on the bones, causing them to move. "
__protein filament that slides over another when a muscle contracts,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,A,"To understand how a muscle contracts, you need to dive deeper into the structure of muscle fibers. You can see in Figure 16.16 that a muscle fiber is full of myofibrils. Each myofibril is made up of two types of proteins, called actin and myosin. These proteins form thread-like filaments. The myosin filaments use energy from ATP to pull on the actin filaments. This causes the actin filaments to slide over the myosin filaments and shorten a section of the myofibril. You can see a simple animation of the process at this link: http://commons.wikimedia.org/wiki/File:Actin_Myosin.gif The sliding-and-shortening process occurs all along many myofibrils and in many muscle fibers. It causes the muscle fibers to shorten and the muscle to contract. "
__most common type of muscle in the body,(A) aactin (B) bcardiac muscle (C) csmooth muscle (D) dmuscle fiber (E) etendon (F) fmyofibril (G) gskeletal muscle,G,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
The human heart is composed almost completely of muscle.,(A) true (B) false,A,"The heart is a muscular organ in the chest. It consists mainly of cardiac muscle tissue. It pumps blood by repeated, rhythmic contractions. This produces the familiar lub-dub sound of each heartbeat. For a good video introduction to the heart and how it works, watch this entertaining Bill Nye video:  MEDIA Click image to the left or use the URL below. URL: "
"When a muscle contracts, it gets longer.",(A) true (B) false,B,"When skeletal muscles contract, bones move. But how do muscles make your bones move? A voluntary muscles usually works across a joint. It is attached to both the bones on either side of the joint by strong cords called tendons. A tendon is a tough band of connective tissue that connects a muscle to a bone. Tendons are similar to ligaments, except that ligaments join bones to each other. Muscles move the body by contracting against the skeleton. When muscles contract, they get shorter. By contracting, muscles pull on bones and allow the body to move. Muscles can only contract. They cannot actively extend, though they can move or relax back into the non-contracted neutral position. Therefore, to move bones in opposite directions, pairs of muscles must work in opposition. Each muscle in the pair works against the other to move bones at the joints of the body. The muscle that contracts to cause a joint to bend is called the flexor. The muscle that contracts to cause the joint to straighten is called the extensor. When one muscle is contracted, the other muscle from the pair is always elongated. For example, the biceps and triceps muscles work together to allow you to bend and straighten your elbow. When you want to bend your elbow, your biceps muscle contracts (Figure 1.1), and, at the same time, the triceps muscle relaxes. The biceps is the flexor, and the triceps is the extensor of your elbow joint. Other muscles that work together are the quadriceps and hamstrings used to bend and straighten the knee, and the pectorals and trapezius used to move the arms and shoulders forward and backward. During daily routines we do not use muscles equally. For example, we use our biceps more than our triceps due to lifting against gravity. "
Actin filaments slide over myosin filaments when a muscle contracts.,(A) true (B) false,A,"To understand how a muscle contracts, you need to dive deeper into the structure of muscle fibers. You can see in Figure 16.16 that a muscle fiber is full of myofibrils. Each myofibril is made up of two types of proteins, called actin and myosin. These proteins form thread-like filaments. The myosin filaments use energy from ATP to pull on the actin filaments. This causes the actin filaments to slide over the myosin filaments and shorten a section of the myofibril. You can see a simple animation of the process at this link: http://commons.wikimedia.org/wiki/File:Actin_Myosin.gif The sliding-and-shortening process occurs all along many myofibrils and in many muscle fibers. It causes the muscle fibers to shorten and the muscle to contract. "
Contractions of skeletal muscles are involuntary.,(A) true (B) false,B,"The muscular system consists of all the muscles in the body. This is the body system that allows us to move. You also depend on many muscles to keep you alive. Your heart, which is mostly muscle, pumps blood around your body. Each muscle in the body is made up of cells called muscle fibers. Muscle fibers are long, thin cells that can do something that other cells cannot dothey are able to get shorter. Shortening of muscle fibers is called contraction. Muscle fibers can contract because they are made of proteins, called actin and myosin, that form long filaments (or fibers). When muscles contract, these protein filaments slide or glide past one another, shortening the length of the cell. When your muscles relax, the length extends back to the previous position. Nearly all movement in the body is the result of muscle contraction. You can control some muscle movements. However, certain muscle movements happen without you thinking about them. Muscles that are under your conscious control are called voluntary muscles. Muscles that are not under your conscious control are called involuntary muscles. Muscle tissue is one of the four types of tissue found in animals. There are three different types of muscle in the body ( Figure 1.1): 1. Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. 2. Smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. These muscles push materials like food or blood through organs. Unlike skeletal muscle, smooth muscle can never be under your control. 3. Cardiac muscle is also an involuntary muscle, found only in the heart. The cardiac muscle fibers all contract together, generating enough force to push blood throughout the body. What would happen if this muscle was under conscious or voluntary control? There are three types of muscles in the body: cardiac, skeletal, and smooth. "
Weight-bearing exercises increase muscle strength.,(A) true (B) false,A,"You can help keep your bones and skeletal system healthy by eating well and getting enough exercise. Weight- bearing exercises help keep bones strong. Weight-bearing exercises and activities work against gravity. Such activities include basketball, tennis, gymnastics, karate, running, and walking. When the body is exercised regularly by performing weight-bearing activity, bones respond by adding more bone cells to increase their bone density. "
Each muscle fiber contains many,(A) nuclei (B) mitochondria (C) myofibrils (D) all of the above,D,"Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils. Myofibrils allow muscles to contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. "
Cardiac muscle is,(A) striated (B) arranged in sheets (C) under conscious control (D) all of the above,A,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
Which statement about smooth muscle is true?,(A) It is arranged in bundles (B) Its contractions are voluntary (C) It is needed for the digestion of food (D) It is found in the walls of all internal organs,C,"Smooth muscles and cardiac muscles are not attached to bone. Recall that these types of muscles are under involuntary control. Smooth muscle is responsible for the contractility of hollow organs, such as blood vessels, the gastrointestinal tract, the bladder, or the uterus. Like skeletal muscles, smooth muscle fibers do contract together, causing the muscle to shorten. Smooth muscles have numerous functions, including the following. The smooth muscle in the uterus helps a woman to push out her baby. In the bladder, smooth muscle helps to push out urine. Smooth muscles move food through the digestive tract. In arteries, smooth muscle movements maintain the arteries diameter. Smooth muscle regulates air flow in lungs. Smooth muscle in the lungs helps the airways to expand and contract as necessary. Smooth muscles in arteries and veins are largely responsible for regulation of blood pressure. Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. If your heart beats 75 times a minute, how many times does it beat in an hour? A day? A year? 85 years? "
How many skeletal muscles are there in the human body?,(A) fewer than 60 (B) about 160 (C) about 320 (D) more than 600,D,The human body has more than 600 skeletal muscles. You can see some of them in Figure 16.18. A few of the larger muscles are labeled in the figure. 
A single muscle can,(A) only contract (B) actively lengthen (C) move a bone back and forth (D) two of the above,A,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
The name of the muscle that bends the arm at the elbow is the,(A) biceps muscle (B) elbow muscle (C) triceps muscle (D) upper arm muscle,A,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
Which form(s) of exercise would increase the strength of cardiac muscle?,(A) running (B) biking (C) weight lifting (D) two of the above,D,"Exercising muscles increases their size, and bigger muscles have greater strength. What type of exercises should you do? For all-round muscular health, you should do two basic types of exercise. To increase the size and strength of skeletal muscles, you need to make these muscles contract against a resisting force. For example, you can do sit-ups or pushups, where the resisting force is your own body weight. You can see another way to do it in Figure 16.21. To exercise cardiac muscle and increase muscle endurance, you need to do aerobic exercise. Aerobic exercise increases the size and strength of muscles in the heart and helps all your muscles develop greater endurance. This means they can work longer without getting tired. Aerobic exercise is any exercise such as running, biking, or swimming that causes an increase in your heart rate. You can see another example of aerobic exercise in Figure 16.22. Lifting weights is one way to pit skeletal muscles against a resisting force. Snowshoeing is a fun way to get aerobic exercise. "
There are four different types of muscle tissues in the human body.,(A) true (B) false,B,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
Aerobic exercise increases muscle endurance.,(A) true (B) false,A,"Aerobic exercises are exercises in which a low to moderate level of exertion can be sustained over long periods. These are exercises that cause your heart to beat faster and allow your muscles to use oxygen to contract. If you exercise aerobically, overtime, your muscles will not get easily tired, and you will use oxygen more efficiently. Aerobic exercise (Figure 1.2) also helps improve cardiac muscle. "
Tendons attach one bone to another at a joint.,(A) true (B) false,B,"You can see the bundles of muscle fibers that make up a skeletal muscle in Figure 16.19. You can also see in the figure how the muscle is attached to a bone by a tendon. Tendons are tough connective tissues that anchor skeletal muscles to bones throughout the body. Many skeletal muscles are attached to the ends of bones where they meet at a joint. The muscles span the joint and connect the bones. When the muscles contract, they pull on the bones, causing them to move. "
Skeletal muscles work in pairs.,(A) true (B) false,A,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
The quadriceps is a muscle in the upper arm.,(A) true (B) false,B,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
Sit-ups and pushups increase muscle size and strength.,(A) true (B) false,A,"Exercising muscles increases their size, and bigger muscles have greater strength. What type of exercises should you do? For all-round muscular health, you should do two basic types of exercise. To increase the size and strength of skeletal muscles, you need to make these muscles contract against a resisting force. For example, you can do sit-ups or pushups, where the resisting force is your own body weight. You can see another way to do it in Figure 16.21. To exercise cardiac muscle and increase muscle endurance, you need to do aerobic exercise. Aerobic exercise increases the size and strength of muscles in the heart and helps all your muscles develop greater endurance. This means they can work longer without getting tired. Aerobic exercise is any exercise such as running, biking, or swimming that causes an increase in your heart rate. You can see another example of aerobic exercise in Figure 16.22. Lifting weights is one way to pit skeletal muscles against a resisting force. Snowshoeing is a fun way to get aerobic exercise. "
Muscle contractions are responsible for virtually all movements of the body.,(A) true (B) false,A,"Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils. Myofibrils allow muscles to contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. "
The six major types of nutrients include,(A) starches (B) amino acids (C) lipids (D) all of the above,C,"There are a variety of substances in foods that the body needs. Any substance in food that the body needs is called a nutrient. There are six major types of nutrients: carbohydrates, proteins, lipids, water, minerals, and vitamins. Carbohydrates, proteins, and lipids can be used for energy. Proteins also provide building materials. Proteins, minerals, and vitamins help control body processes. Water is needed by all cells just to stay alive. The six types of nutrients can be divided into two major categories based on how much of them the body needs. The categories are macronutrients and micronutrients. "
__state in which the body does not contain enough water,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,D,"Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water? You lose water in your breath each time you exhale. You lose water in urine. You lose water in sweat, especially if you are active in warm weather. The boy in Figure 17.5 is taking a water break while playing outside on a hot day. If he doesnt take in enough water to replace the water lost in sweat, he may become dehydrated. Symptoms of dehydration include dry mouth, headache, and dizziness. Dehydration can be very serious. It can even cause death. "
__any nutrient the body needs in relatively small amounts,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,F,"Micronutrients are nutrients the body needs in relatively small amounts. They include minerals and vitamins. These nutrients dont provide the body with energy, but they are still essential for good health. "
Macronutrients include all of the following except,(A) carbohydrates (B) water (C) proteins (D) vitamins,D,"Macronutrients are nutrients the body needs in relatively large amounts. They include carbohydrates, proteins, lipids, and water. "
The food we eat provides our body with,(A) building materials (B) energy (C) nutrients (D) all of the above,D,Your body needs food for three purposes: 1. Food gives the body energy. You need energy for everything you do. The energy in food is measured in a unit called the Calorie. 2. Food provides building materials for the body. The body needs building materials for growth and repair. 3. Food contains substances that help control body processes. Body processes must be kept in balance for good health. 
__chemical element needed in small amounts for normal functioning of the body,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,G,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
__artificial lipid added to foods to preserve freshness,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,A,"Lipids are nutrients, such as fats that store energy. Lipids also have several other roles in the body. For example, lipids protect nerves and make up the membranes that surround cells. Fats are one type of lipid. Stored fat gives your body energy to use for later. Its like having money in a savings account: its there in case you need it. Stored fat also cushions and protects internal organs. In addition, it insulates the body. It helps keep you warm in cold weather. Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. Seafood and eggs are other good sources of protein. There are two main types of fats, saturated and unsaturated. 1. Saturated fats can be unhealthy, even in very small amounts. They are found mainly in animal foods, such as meats, whole milk, and eggs. So even though these foods are good sources of proteins, they should be eaten in limited amounts. Saturated lipids increase cholesterol levels in the blood. Too much cholesterol in the blood Another type of lipid is called trans fat. Trans fats are manufactured and added to certain foods to keep them fresher for longer. Foods that contain trans fats include cakes, cookies, fried foods, and margarine. Eating foods that contain trans fats increases the risk of heart disease. Beginning with Denmark in 2003, many nations now limit the amount of trans fat that can be in food products or ban these products all together. On January 1, 2008, Calgary became the first city in Canada to ban trans fats from restaurants and fast food chains. Beginning in 2010, California banned trans fats from restaurant products, and in 2011, from all retail baked goods. "
Which type of food is a good source of sugar?,(A) milk (B) fish (C) beans (D) meat,A,"Carbohydrates are nutrients that include sugars, starches, and fiber. There are two types of carbohydrates: simple and complex. Pictured below are some foods that are good sources of carbohydrates ( Figure 1.1). "
__any nutrient the body needs in relatively large amounts,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,B,"Macronutrients are nutrients the body needs in relatively large amounts. They include carbohydrates, proteins, lipids, and water. "
The body needs lipids for,(A) cell membranes (B) muscles (C) enzymes (D) all of the above,A,"Lipids are nutrients such as fats. They are used for energy and other important purposes. One gram of lipids provides the body with 9 Calories of energy, more than twice as much as carbohydrates or proteins. Lipids also make up cell membranes, protect nerves, control blood pressure, and help blood clot. You must consume some lipids for these purposes. Good food sources of lipids are shown in Figure 17.4. Any extra lipids you consume are stored as fat. A certain amount of stored fat is needed to cushion and protect internal organs and insulate the body. However, too much stored fat can lead to obesity and cause significant health problems. A type of lipid called trans fat is found in many processed foods. Trans fat is rare in nature but is manufactured and added to foods to preserve freshness. Eating foods that contain trans fat increases the risk of heart disease. Trans fat may be found in such foods as cookies, doughnuts, crackers, fried foods, ground beef, and margarine. "
__nutrient made up of amino acids,(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,E,"Proteins are nutrients made up of smaller molecules called amino acids. The digestive system breaks down proteins in food to amino acids, which are used for protein synthesis. Proteins synthesized from the amino acids in food serve many vital functions. They make up muscles, control body processes, fight infections, and carry substances in the blood. If you eat more protein than you need for these functions, the extra protein is used for energy. One gram of protein provides 4 Calories of energy, the same as carbohydrates. A 13-year-old needs to eat about 34 grams of protein a day. Figure 17.3 shows good food sources of protein. "
"__sugar, starch, or fiber",(A) atrans fat (B) bmacronutrient (C) ccarbohydrate (D) ddehydration (E) eprotein (F) fmicronutrient (G) gmineral,C,"Starch is a large, complex carbohydrate made of thousands of glucose units (monomers) joined together. Starches are found in foods such as vegetables and grains. Starches are broken down by the body into sugars that provide energy. Breads and pasta are good sources of complex carbohydrates. Fiber is another type of large, complex carbohydrate that is partly indigestible. Unlike sugars and starches, fiber does not provide energy. However, it has other important roles in the body. For example, fiber is important for maintaining the health of your gastrointestinal tract. Eating foods high in fiber also helps fill you up without providing too many calories. Most fruits and vegetables are high in fiber. Some examples are pictured below ( Figure 1.2). "
All nutrients provide the body with energy.,(A) true (B) false,B,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
Your body cannot produce any of the vitamins it needs.,(A) true (B) false,B,"Vitamins are organic compounds that the body needs in small amounts to function properly. Humans need 13 different vitamins. Some of them are listed below ( Table 1.1). The table also shows how much of each vitamin you need every day. Vitamins have many roles in the body. For example, Vitamin A helps maintain good vision. Vitamin B9 helps form red blood cells. Vitamin K is needed for blood to clot when you have a cut or other wound. Vitamin Necessary for Available from Daily Amount Required (at ages 913 years) Vitamin Necessary for Available from A Good vision B1 Healthy nerves B3 Healthy skin and nerves B9 Red blood cells B12 Healthy nerves C Growth and repair of tis- sues Healthy bones and teeth Blood to clot Carrots, spinach, milk, eggs Whole wheat, peas, meat, beans, fish, peanuts Beets, liver, pork, turkey, fish, peanuts Liver, peas, dried beans, leafy green vegetables Meat, liver, milk, shell- fish, eggs Oranges, grapefruits, red peppers, broccoli Milk, salmon, tuna, eggs Spinach, brussels sprouts, milk, eggs D K Daily Amount Required (at ages 913 years) 600 g (1 g = 1  106 g) 0.9 mg (1 mg = 1  103 g) 12 mg 300 g 1.8 g 45 mg 5 g 60 g Some vitamins are produced in the body. For example, vitamin D is made in the skin when it is exposed to sunlight. Vitamins B12 and K are produced by bacteria that normally live inside the body. Most other vitamins must come from foods. Foods that are good sources of vitamins include whole grains, vegetables, fruits, and milk ( Table 1.1). Not getting enough vitamins can cause health problems. For example, too little vitamin C causes a disease called scurvy. People with scurvy have bleeding gums, nosebleeds, and other symptoms. "
The mineral sodium is needed for normal muscle function.,(A) true (B) false,A,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
Vitamin K is needed for normal nerve function.,(A) true (B) false,B,"Vitamins are organic compounds that the body needs in small amounts to function properly. Humans need 13 different vitamins. Some of them are listed below ( Table 1.1). The table also shows how much of each vitamin you need every day. Vitamins have many roles in the body. For example, Vitamin A helps maintain good vision. Vitamin B9 helps form red blood cells. Vitamin K is needed for blood to clot when you have a cut or other wound. Vitamin Necessary for Available from Daily Amount Required (at ages 913 years) Vitamin Necessary for Available from A Good vision B1 Healthy nerves B3 Healthy skin and nerves B9 Red blood cells B12 Healthy nerves C Growth and repair of tis- sues Healthy bones and teeth Blood to clot Carrots, spinach, milk, eggs Whole wheat, peas, meat, beans, fish, peanuts Beets, liver, pork, turkey, fish, peanuts Liver, peas, dried beans, leafy green vegetables Meat, liver, milk, shell- fish, eggs Oranges, grapefruits, red peppers, broccoli Milk, salmon, tuna, eggs Spinach, brussels sprouts, milk, eggs D K Daily Amount Required (at ages 913 years) 600 g (1 g = 1  106 g) 0.9 mg (1 mg = 1  103 g) 12 mg 300 g 1.8 g 45 mg 5 g 60 g Some vitamins are produced in the body. For example, vitamin D is made in the skin when it is exposed to sunlight. Vitamins B12 and K are produced by bacteria that normally live inside the body. Most other vitamins must come from foods. Foods that are good sources of vitamins include whole grains, vegetables, fruits, and milk ( Table 1.1). Not getting enough vitamins can cause health problems. For example, too little vitamin C causes a disease called scurvy. People with scurvy have bleeding gums, nosebleeds, and other symptoms. "
Proteins can provide the body with energy.,(A) true (B) false,A,"Proteins are nutrients made up of smaller molecules called amino acids. The digestive system breaks down proteins in food to amino acids, which are used for protein synthesis. Proteins synthesized from the amino acids in food serve many vital functions. They make up muscles, control body processes, fight infections, and carry substances in the blood. If you eat more protein than you need for these functions, the extra protein is used for energy. One gram of protein provides 4 Calories of energy, the same as carbohydrates. A 13-year-old needs to eat about 34 grams of protein a day. Figure 17.3 shows good food sources of protein. "
Your body needs food for,(A) energy (B) growth and repair of body tissues (C) control of body processes (D) all of the above,D,Your body needs food for three purposes: 1. Food gives the body energy. You need energy for everything you do. The energy in food is measured in a unit called the Calorie. 2. Food provides building materials for the body. The body needs building materials for growth and repair. 3. Food contains substances that help control body processes. Body processes must be kept in balance for good health. 
There are six major types of nutrients. One of the six types is,(A) water (B) trans fat (C) glucose (D) fiber,A,"There are a variety of substances in foods that the body needs. Any substance in food that the body needs is called a nutrient. There are six major types of nutrients: carbohydrates, proteins, lipids, water, minerals, and vitamins. Carbohydrates, proteins, and lipids can be used for energy. Proteins also provide building materials. Proteins, minerals, and vitamins help control body processes. Water is needed by all cells just to stay alive. The six types of nutrients can be divided into two major categories based on how much of them the body needs. The categories are macronutrients and micronutrients. "
Micronutrients include,(A) starches (B) minerals (C) fiber (D) proteins,B,"Micronutrients are nutrients the body needs in relatively small amounts. They include minerals and vitamins. These nutrients dont provide the body with energy, but they are still essential for good health. "
Roles of proteins in the body include,(A) making up cell membranes (B) helping blood clot (C) keeping bones strong (D) fighting infections,D,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
How many Calories are provided by one gram of lipids?,(A) 4 (B) 5 (C) 8 (D) 9,D,"Lipids are nutrients such as fats. They are used for energy and other important purposes. One gram of lipids provides the body with 9 Calories of energy, more than twice as much as carbohydrates or proteins. Lipids also make up cell membranes, protect nerves, control blood pressure, and help blood clot. You must consume some lipids for these purposes. Good food sources of lipids are shown in Figure 17.4. Any extra lipids you consume are stored as fat. A certain amount of stored fat is needed to cushion and protect internal organs and insulate the body. However, too much stored fat can lead to obesity and cause significant health problems. A type of lipid called trans fat is found in many processed foods. Trans fat is rare in nature but is manufactured and added to foods to preserve freshness. Eating foods that contain trans fat increases the risk of heart disease. Trans fat may be found in such foods as cookies, doughnuts, crackers, fried foods, ground beef, and margarine. "
Vitamins made by bacteria in the gut include vitamin,(A) A (B) B12  (C) D (D) two of the above,B,"Your large intestine is not just made up of cells. It is also an ecosystem, home to trillions of bacteria known as the ""gut flora"" ( Figure 1.1). But dont worry, most of these bacteria are helpful. Friendly bacteria live mostly in the large intestine and part of the small intestine. The acidic environment of the stomach does not allow bacterial growth. Gut bacteria have several roles in the body. For example, intestinal bacteria: Produce vitamin B12 and vitamin K. Control the growth of harmful bacteria. Break down poisons in the large intestine. Break down some substances in food that cannot be digested, such as fiber and some starches and sugars. Bacteria produce enzymes that digest carbohydrates in plant cell walls. Most of the nutritional value of plant material would be wasted without these bacteria. These help us digest plant foods like spinach. Your intestines are home to trillions of bacteria. A wide range of friendly bacteria live in the gut. Bacteria begin to populate the human digestive system right after birth. Gut bacteria include Lactobacillus, the bacteria commonly used in probiotic foods such as yogurt, and E. coli bacteria. About a third of all bacteria in the gut are members of the Bacteroides species. Bacteroides are key in helping us digest plant food. It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet. The bacteria in your digestive system are from anywhere between 300 and 1000 species. As these bacteria are helpful, your body does not attack them. They actually appear to the bodys immune system as cells of the digestive system, not foreign invaders. The bacteria actually cover themselves with sugar molecules removed from the actual cells of the digestive system. This disguises the bacteria and protects them from the immune system. As the bacteria that live in the human gut are beneficial to us, and as the bacteria enjoy a safe environment to live, the relationship that we have with these tiny organisms is described as mutualism, a type of symbiotic relationship. Lastly, keep in mind the small size of bacteria. Together, all the bacteria in your gut may weight just about 2 pounds. "
All of the following types of nutrients can be used for energy except,(A) vitamins (B) proteins (C) carbohydrates (D) lipids,A,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
All carbohydrates provide the body with energy.,(A) true (B) false,B,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
Fiber helps keep sugar and lipids at normal levels in the blood.,(A) true (B) false,A,"Cholesterol cant dissolve in the blood. It has to be transported to and from the cells by carriers called lipoproteins. Low-density lipoprotein, or LDL, is known as ""bad"" cholesterol. High-density lipoprotein (HDL) is known as good cholesterol. When too much LDL cholesterol circulates in the blood, it can slowly build up in the inner walls of the The USDAs MyPyramid recommends that you limit the amount of such foods in your diet to occasional treats. arteries that feed the heart and brain. Together with other substances, it can form plaque, and lead to atherosclerosis. If a clot forms and blocks a narrowed artery, a heart attack or stroke can result. Cholesterol comes from the food you eat as well as being made by the body. To lower bad cholesterol, a diet low in saturated fat and dietary cholesterol should be followed. Regular aerobic exercise also lowers LDL cholesterol and increases HDL cholesterol. "
Carbohydrates and proteins provide 4 Calories of energy per gram.,(A) true (B) false,A,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
Eating trans fats can increase the risk of heart disease.,(A) true (B) false,A,"Lipids are nutrients, such as fats that store energy. Lipids also have several other roles in the body. For example, lipids protect nerves and make up the membranes that surround cells. Fats are one type of lipid. Stored fat gives your body energy to use for later. Its like having money in a savings account: its there in case you need it. Stored fat also cushions and protects internal organs. In addition, it insulates the body. It helps keep you warm in cold weather. Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. Seafood and eggs are other good sources of protein. There are two main types of fats, saturated and unsaturated. 1. Saturated fats can be unhealthy, even in very small amounts. They are found mainly in animal foods, such as meats, whole milk, and eggs. So even though these foods are good sources of proteins, they should be eaten in limited amounts. Saturated lipids increase cholesterol levels in the blood. Too much cholesterol in the blood Another type of lipid is called trans fat. Trans fats are manufactured and added to certain foods to keep them fresher for longer. Foods that contain trans fats include cakes, cookies, fried foods, and margarine. Eating foods that contain trans fats increases the risk of heart disease. Beginning with Denmark in 2003, many nations now limit the amount of trans fat that can be in food products or ban these products all together. On January 1, 2008, Calgary became the first city in Canada to ban trans fats from restaurants and fast food chains. Beginning in 2010, California banned trans fats from restaurant products, and in 2011, from all retail baked goods. "
Your body can produce some of the minerals it needs.,(A) true (B) false,B,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
Potassium is needed for strong bones and teeth.,(A) true (B) false,B,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
Vitamin B12 is needed for normal nerve function.,(A) true (B) false,A,"Vitamins are organic compounds that the body needs in small amounts to function properly. Humans need 13 different vitamins. Some of them are listed below ( Table 1.1). The table also shows how much of each vitamin you need every day. Vitamins have many roles in the body. For example, Vitamin A helps maintain good vision. Vitamin B9 helps form red blood cells. Vitamin K is needed for blood to clot when you have a cut or other wound. Vitamin Necessary for Available from Daily Amount Required (at ages 913 years) Vitamin Necessary for Available from A Good vision B1 Healthy nerves B3 Healthy skin and nerves B9 Red blood cells B12 Healthy nerves C Growth and repair of tis- sues Healthy bones and teeth Blood to clot Carrots, spinach, milk, eggs Whole wheat, peas, meat, beans, fish, peanuts Beets, liver, pork, turkey, fish, peanuts Liver, peas, dried beans, leafy green vegetables Meat, liver, milk, shell- fish, eggs Oranges, grapefruits, red peppers, broccoli Milk, salmon, tuna, eggs Spinach, brussels sprouts, milk, eggs D K Daily Amount Required (at ages 913 years) 600 g (1 g = 1  106 g) 0.9 mg (1 mg = 1  103 g) 12 mg 300 g 1.8 g 45 mg 5 g 60 g Some vitamins are produced in the body. For example, vitamin D is made in the skin when it is exposed to sunlight. Vitamins B12 and K are produced by bacteria that normally live inside the body. Most other vitamins must come from foods. Foods that are good sources of vitamins include whole grains, vegetables, fruits, and milk ( Table 1.1). Not getting enough vitamins can cause health problems. For example, too little vitamin C causes a disease called scurvy. People with scurvy have bleeding gums, nosebleeds, and other symptoms. "
Food passes through all of these digestive organs except the,(A) mouth (B) stomach (C) small intestine (D) pancreas,D,"The mouth and stomach are just two of the organs of the digestive system. Other digestive system organs are the esophagus, small intestine, and large intestine. Below, you can see that the digestive organs form a long tube ( Figure 1.1). In adults, this tube is about 30 feet long! At one end of the tube is the mouth. At the other end is the anus. Food enters the mouth and then passes through the rest of the digestive system. Food waste leaves the body through the anus. The organs of the digestive system are lined with muscles. The muscles contract, or tighten, to push food through the system ( Figure 1.2). The muscles contract in waves. The waves pass through the digestive system like waves through a slinky. This movement of muscle contractions is called peristalsis. Without peristalsis, food would not be able to move through the digestive system. Peristalsis is an involuntary process, which means that it occurs without your conscious control. The liver, gallbladder, and pancreas are also organs of the digestive system ( Figure 1.1). Food does not pass through these three organs. However, these organs are important for digestion. They secrete or store enzymes or other chemicals that are needed to help digest food chemically. "
Organs of the GI tract include the,(A) liver (B) pancreas (C) stomach (D) all of the above,C,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
Chemical digestion takes place mainly in the,(A) mouth (B) esophagus (C) stomach (D) small intestine,D,"As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks of food are broken down into smaller pieces. This is a physical process that happens mainly in the mouth and stomach. Chemical digestion occurs when large food molecules are broken down into smaller nutrient molecules. This is a chemical process that begins in the mouth and stomach but occurs mainly in the small intestine. "
In which organ(s) does chemical digestion take place?,(A) mouth (B) stomach (C) small intestine (D) all of the above,D,"As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks of food are broken down into smaller pieces. This is a physical process that happens mainly in the mouth and stomach. Chemical digestion occurs when large food molecules are broken down into smaller nutrient molecules. This is a chemical process that begins in the mouth and stomach but occurs mainly in the small intestine. "
Which type of molecule does pepsin help digest?,(A) protein (B) carbohydrate (C) lipid (D) RNA,A,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
Which digestive enzyme is produced in the mouth?,(A) amylase (B) pepsin (C) lipase (D) ribonuclease,A,"The mouth is the first digestive organ that food enters. The sight, smell, or taste of food stimulates the release of saliva and digestive enzymes by salivary glands inside the mouth. Saliva wets the food, which makes it easier to break up and swallow. The enzyme amylase in saliva begins the chemical digestion of starches to sugars. Your teeth help to mechanically digest food. Look at the different types of human teeth in Figure 17.13. Sharp teeth in the front of the mouth cut or tear food when you bite into it. Broad teeth in the back of the mouth grind food when you chew. Your tongue helps mix the food with saliva and enzymes and also helps you swallow. When you swallow, a lump of chewed food passes from the mouth into a tube in your throat called the pharynx. From the pharynx, the food passes into the esophagus. "
Which statement about bile acids is false?,(A) They are secreted by the pancreas (B) They are stored in the gall bladder (C) They are released into the small intestine (D) They are needed to help digest fat,A,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
Which statement about bacteria in the large intestine is false?,(A) Trillions of bacteria normally live in the large intestine (B) Most of the bacteria in the large intestine are beneficial (C) Some of the bacteria in the large intestine make vitamins (D) none of the above,D,"Your large intestine is not just made up of cells. It is also an ecosystem, home to trillions of bacteria known as the ""gut flora"" ( Figure 1.1). But dont worry, most of these bacteria are helpful. Friendly bacteria live mostly in the large intestine and part of the small intestine. The acidic environment of the stomach does not allow bacterial growth. Gut bacteria have several roles in the body. For example, intestinal bacteria: Produce vitamin B12 and vitamin K. Control the growth of harmful bacteria. Break down poisons in the large intestine. Break down some substances in food that cannot be digested, such as fiber and some starches and sugars. Bacteria produce enzymes that digest carbohydrates in plant cell walls. Most of the nutritional value of plant material would be wasted without these bacteria. These help us digest plant foods like spinach. Your intestines are home to trillions of bacteria. A wide range of friendly bacteria live in the gut. Bacteria begin to populate the human digestive system right after birth. Gut bacteria include Lactobacillus, the bacteria commonly used in probiotic foods such as yogurt, and E. coli bacteria. About a third of all bacteria in the gut are members of the Bacteroides species. Bacteroides are key in helping us digest plant food. It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet. The bacteria in your digestive system are from anywhere between 300 and 1000 species. As these bacteria are helpful, your body does not attack them. They actually appear to the bodys immune system as cells of the digestive system, not foreign invaders. The bacteria actually cover themselves with sugar molecules removed from the actual cells of the digestive system. This disguises the bacteria and protects them from the immune system. As the bacteria that live in the human gut are beneficial to us, and as the bacteria enjoy a safe environment to live, the relationship that we have with these tiny organisms is described as mutualism, a type of symbiotic relationship. Lastly, keep in mind the small size of bacteria. Together, all the bacteria in your gut may weight just about 2 pounds. "
Bacteria in the large intestine,(A) break down toxins (B) produce vitamins (C) control the growth of harmful bacteria (D) all of the above,D,"Trillions of bacteria normally live in the large intestine. Dont worrymost of them are helpful. They have several important roles. For example, intestinal bacteria: produce vitamins B12 and K. control the growth of harmful bacteria. break down toxins in the large intestine. break down fiber and some other substances in food that cant be digested. "
Which structures increase the ability of the small intestine to absorb nutrients?,(A) villi (B) glands (C) sphincters (D) ducts,A,"The small intestine a is narrow tube that starts at the stomach and ends at the large intestine ( Figure 1.1). In adults, the small intestine is about 23 feet long. Chemical digestion takes place in the first part of the small intestine. Many enzymes and other chemicals are secreted here. The small intestine is also where most nutrients are absorbed into the blood. The later sections of the small intestines are covered with tiny projections called villi ( Figure 1.3). Villi contain very tiny blood vessels. Nutrients are absorbed into the blood through these tiny vessels. There are millions of villi, so, altogether, there is a very large area for absorption to take place. In fact, villi make the inner surface area of the small intestine 1,000 times larger than it would be without them. The entire inner surface area of the small intestine is about as big as a basketball court! The small intestine is much longer than the large intestine. So why is it called small? If you compare small and large intestines ( Figure 1.1), you will see the small intestine is smaller in width than the large intestine. "
The digestive enzyme that helps digest fats is,(A) amylase (B) pepsin (C) lipase (D) ribonuclease,C,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
Mechanical digestion takes place in the,(A) mouth (B) stomach (C) small intestine (D) two of the above,D,"As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks of food are broken down into smaller pieces. This is a physical process that happens mainly in the mouth and stomach. Chemical digestion occurs when large food molecules are broken down into smaller nutrient molecules. This is a chemical process that begins in the mouth and stomach but occurs mainly in the small intestine. "
The gall bladder stores bile acids from the liver.,(A) true (B) false,A,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
Food moves through the digestive tract by gravity.,(A) true (B) false,B,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
Digestive enzymes speed up mechanical digestion.,(A) true (B) false,B,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
Lipase is an enzyme that helps digest fat.,(A) true (B) false,A,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
Absorption takes place only in the small intestine.,(A) true (B) false,B,"The small intestine a is narrow tube that starts at the stomach and ends at the large intestine ( Figure 1.1). In adults, the small intestine is about 23 feet long. Chemical digestion takes place in the first part of the small intestine. Many enzymes and other chemicals are secreted here. The small intestine is also where most nutrients are absorbed into the blood. The later sections of the small intestines are covered with tiny projections called villi ( Figure 1.3). Villi contain very tiny blood vessels. Nutrients are absorbed into the blood through these tiny vessels. There are millions of villi, so, altogether, there is a very large area for absorption to take place. In fact, villi make the inner surface area of the small intestine 1,000 times larger than it would be without them. The entire inner surface area of the small intestine is about as big as a basketball court! The small intestine is much longer than the large intestine. So why is it called small? If you compare small and large intestines ( Figure 1.1), you will see the small intestine is smaller in width than the large intestine. "
All the organs of the digestive system are part of the GI tract.,(A) true (B) false,B,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
"After food is digested and its nutrients absorbed, the only thing that remains in the GI tract is water.",(A) true (B) false,B,Some substances in food cant be broken down into nutrients. They remain behind in the digestive system after the nutrients have been absorbed. Any substances in food that cant be digested pass out of the body as solid waste. This process is called elimination. 
One function of the gall bladder is to make bile acids more concentrated.,(A) true (B) false,A,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
Substances that can be absorbed from the stomach include water and salt.,(A) true (B) false,A,"The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls that contract and relax to squeeze and mix food. This helps break the food into smaller pieces. It also helps mix the food with enzymes and other secretions in the stomach. For example, the stomach secretes the enzyme pepsin, which helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the lining of the stomach. However, most substances must undergo further digestion in the small intestine before they can be absorbed. The stomach stores the partly digested food until the small intestine is empty. Then a sphincter between the stomach and small intestine relaxes, allowing food to enter the small intestine. "
The large intestine is much longer than the small intestine.,(A) true (B) false,B,"The large intestine is a wide tube that connects the small intestine with the anus. In adults, the large intestine is about 1.5 meters (5 feet) long. It is larger in width but shorter in length than the small intestine. "
The part of the small intestine where most digestion takes place is the ileum.,(A) true (B) false,B,"The small intestine is a narrow tube that starts at the stomach and ends at the large intestine. In adults, its about 7 meters (23 feet) long. Most chemical digestion and almost all nutrient absorption take place in the small intestine. The small intestine is made up of three parts: 1. The duodenum is the first part of the small intestine. It is also the shortest part. This is where most chemical digestion takes place. Many enzymes and other substances involved in digestion are secreted into the duodenum 2. The jejunum is the second part of the small intestine. This is where most nutrients are absorbed into the blood. The inside surface of the jejunum is covered with tiny projections called villi (villus, singular). The villi make the inner surface of the small intestine 1000 times greater than it would be without them. You can read in Figure 17.14 how villi are involved in absorption. 3. The ileum is the last part of the small intestine. It is covered with villi like the jejunum. A few remaining nutrients are absorbed in the ileum. From the ileum, any remaining food waste passes into the large intestine. "
Foodborne illness is the common term for a food allergy.,(A) true (B) false,B,"Food allergies occur when the immune system reacts to harmless substances in food as though they were harmful germs. Food allergies are relatively common. Almost 10 percent of children have them. Some of the foods most likely to cause allergies include milk, shellfish, nuts, grains, and eggs. If you eat foods to which you are allergic, you may experience vomiting, diarrhea, or a rash. In some people, eating even tiny amounts of certain foods causes them to have serious symptoms, such as difficulty breathing. They need immediate medical attention. The best way to prevent food allergy symptoms is to avoid eating the offending food. This may require careful reading of food labels. "
__breaking down of large chunks of food into smaller pieces,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,G,"As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks of food are broken down into smaller pieces. This is a physical process that happens mainly in the mouth and stomach. Chemical digestion occurs when large food molecules are broken down into smaller nutrient molecules. This is a chemical process that begins in the mouth and stomach but occurs mainly in the small intestine. "
__passage of solid food waste out of the body,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,E,"Food waste enters the large intestine from the small intestine in a liquid state. As the waste moves through the large intestine, excess water is absorbed from it. The remaining solid waste is called feces. After a certain amount of feces have collected, a sphincter relaxes to let the feces pass out of the body through the anus. This is elimination. "
__organ that carries food from the pharynx to the stomach,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,F,"The esophagus is a long, narrow tube that carries food from the pharynx to the stomach. It has no other purpose. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle, called a sphincter, controls the opening to the stomach. The sphincter relaxes to let food pass into the stomach. Then the sphincter contracts to prevent food from passing back into the esophagus. "
__organ than secretes lipase and ribonuclease,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,A,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
__organs of the digestive system through which food actually passes as it undergoes digestion,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,B,"The mouth and stomach are just two of the organs of the digestive system. Other digestive system organs are the esophagus, small intestine, and large intestine. Below, you can see that the digestive organs form a long tube ( Figure 1.1). In adults, this tube is about 30 feet long! At one end of the tube is the mouth. At the other end is the anus. Food enters the mouth and then passes through the rest of the digestive system. Food waste leaves the body through the anus. The organs of the digestive system are lined with muscles. The muscles contract, or tighten, to push food through the system ( Figure 1.2). The muscles contract in waves. The waves pass through the digestive system like waves through a slinky. This movement of muscle contractions is called peristalsis. Without peristalsis, food would not be able to move through the digestive system. Peristalsis is an involuntary process, which means that it occurs without your conscious control. The liver, gallbladder, and pancreas are also organs of the digestive system ( Figure 1.1). Food does not pass through these three organs. However, these organs are important for digestion. They secrete or store enzymes or other chemicals that are needed to help digest food chemically. "
__breaking down of large food molecules into smaller nutrient molecules,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,C,"After food is broken down into nutrient molecules, the molecules are absorbed by the blood. Absorption is the process in which nutrients or other molecules are taken up by the blood. Once absorbed by the blood, nutrients can travel in the bloodstream to cells throughout the body. "
__organ that secretes bile acids,(A) apancreas (B) bgastrointestinal tract (C) cchemical digestion (D) dliver (E) eelimination (F) fesophagus (G) gmechanical digestion,D,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
Substances carried in the blood include,(A) carbon dioxide (B) glucose (C) oxygen (D) all of the above,D,"Blood consists of both liquid and cells. The liquid part of blood is called plasma. Plasma is a watery, golden-yellow fluid that contains many dissolved substances. Substances dissolved in plasma include glucose, proteins, and gases. Plasma also contains blood cells. There are three types of blood cells: red blood cells, white blood cells, and platelets. You can see all three types in Figure 18.8. 1. Red blood cells are shaped like flattened disks. There are trillions of red blood cells in your blood. Each red blood cell has millions of molecules of hemoglobin. Hemoglobin is a protein that contains iron. The iron in hemoglobin gives red blood cells their red color. It also explains how hemoglobin carries oxygen. The iron in hemoglobin binds with oxygen molecules so they can be carried by red blood cells. 2. White blood cells are larger than red blood cells, but there are far fewer of them. Their role is to defend the body in various ways. For example, white blood cells called phagocytes engulf and destroy microorganisms and debris in the blood. 3. Platelets are small, sticky cell fragments that help blood clot. A blood clot is a solid mass of cell fragments and other substances that plugs a leak in a damaged blood vessel. Platelets stick to tears in blood vessels and to each other, helping to form a clot at the site of injury. Platelets also release chemicals that are needed for clotting to occur. "
__shorter of two loops that make up the cardiovascular system,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,A,"The heart and blood vessels form a closed system through which blood keeps circulating. However, blood actually circulates in two different loops within this closed system. The two loops are called pulmonary circulation and systemic circulation. In both loops, blood passes through the heart. You can see a simple model of each circulation loop in Figure 18.2. As blood circulates through the body, it travels first through one loop and then the other loop, over and over again. "
__major function of the cardiovascular system,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,G,"Your cardiovascular system has many jobs. At times the cardiovascular system can work like a pump, a heating system, or even a postal carrier. To do these tasks, your cardiovascular system works with other organ systems, such as the respiratory, endocrine, and nervous systems. The cardiovascular system (Figure 1.1) is made up of the heart, the blood vessels, and the blood. It moves nutrients, gases (like oxygen), and wastes to and from your cells. Every cell in your body depends on your cardiovascular system. If your cells dont receive nutrients, they cannot survive. The main function of the cardiovascular system is to deliver oxygen to each of your cells. Blood receives oxygen in your lungs (the main organs of the respiratory system) and then is pumped, by your heart, throughout your body. The oxygen then diffuses into your cells, and carbon dioxide, a waste product of cellular respiration, moves from your cells into your blood to be delivered back to your lungs and exhaled. Each cell in your body needs oxygen, as oxygen is used in cellular respiration to produce energy in the form of ATP. Without oxygen, lactic acid fermentation would occur in your cells, which can only be maintained for a brief period of time. Arteries carry blood full of oxygen (""oxygen-rich"") away from the heart and veins return oxygen-poor blood back to the heart. The cardiovascular system also plays a role in maintaining body temperature. It helps to keep you warm by moving warm blood around your body. Your blood vessels also control your body temperature to keep you from getting too hot or too cold. When your brain senses that your body temperature is increasing, it sends messages to the blood vessels in the skin to increase in diameter. Increasing the diameter of the blood vessels increases the amount of blood and heat that moves near the skins surface. The heat is then released from the skin. This helps you cool down. What do you think your blood vessels do when your body temperature is decreasing? The blood also carries hormones, which are chemical messenger molecules produced by organs of the endocrine system, through your body. Hormones are produced in one area of your body and have an effect on another area. To get to that other area, they must travel through your blood. An example is the hormone adrenaline, produced by the adrenal glands on top of the kidneys. Adrenaline has multiple effects on the heart (it quickens the heart rate), on muscles and on the airway. "
The systemic circulation,(A) is the shorter loop of the cardiovascular system (B) carries oxygen-rich blood from the lungs to the heart (C) delivers oxygen to cells throughout the body (D) two of the above,C,"Systemic circulation is the longer loop of the cardiovascular system. It carries blood between the heart and the rest of the body. Oxygen-rich blood flows from the heart to cells throughout the body. As it passes cells, the blood releases oxygen and absorbs carbon dioxide. Then the oxygen-poor blood returns to the heart. "
Carbon dioxide and other cellular wastes are picked up by the blood from cells throughout the body and carried to the,(A) kidneys (B) heart (C) lungs (D) all of the above,D,"The cells of the body have a lower concentration of oxygen that does blood in the capillaries that supply body cells. Therefore, oxygen diffuses from the blood into the cells. Carbon dioxide, which cells produce in cellular respiration, is more concentrated in the cells. Therefore, carbon dioxide diffuses out of the cells and into the blood. The carbon dioxide travels in capillaries to veins and then to the heart. The heart pumps the blood to the lungs, where the carbon dioxide diffuses into the alveoli. It passes out of the body during exhalation. This brings the process of respiration full circle. "
"__system comprised of the heart, blood vessels, and blood",(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,D,The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure 18.1 shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. 
__longer of two loops that make up the cardiovascular system,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,E,"Systemic circulation is the longer loop of the cardiovascular system. It carries blood between the heart and the rest of the body. Oxygen-rich blood flows from the heart to cells throughout the body. As it passes cells, the blood releases oxygen and absorbs carbon dioxide. Then the oxygen-poor blood returns to the heart. "
The cardiovascular system can cool the body by,(A) increasing blood flow to the bodys surface (B) decreasing the metabolic rate of body cells (C) pumping less blood to the skin (D) slowing down the heart rate,A,"Your cardiovascular system has many jobs. At times the cardiovascular system can work like a pump, a heating system, or even a postal carrier. To do these tasks, your cardiovascular system works with other organ systems, such as the respiratory, endocrine, and nervous systems. The cardiovascular system (Figure 1.1) is made up of the heart, the blood vessels, and the blood. It moves nutrients, gases (like oxygen), and wastes to and from your cells. Every cell in your body depends on your cardiovascular system. If your cells dont receive nutrients, they cannot survive. The main function of the cardiovascular system is to deliver oxygen to each of your cells. Blood receives oxygen in your lungs (the main organs of the respiratory system) and then is pumped, by your heart, throughout your body. The oxygen then diffuses into your cells, and carbon dioxide, a waste product of cellular respiration, moves from your cells into your blood to be delivered back to your lungs and exhaled. Each cell in your body needs oxygen, as oxygen is used in cellular respiration to produce energy in the form of ATP. Without oxygen, lactic acid fermentation would occur in your cells, which can only be maintained for a brief period of time. Arteries carry blood full of oxygen (""oxygen-rich"") away from the heart and veins return oxygen-poor blood back to the heart. The cardiovascular system also plays a role in maintaining body temperature. It helps to keep you warm by moving warm blood around your body. Your blood vessels also control your body temperature to keep you from getting too hot or too cold. When your brain senses that your body temperature is increasing, it sends messages to the blood vessels in the skin to increase in diameter. Increasing the diameter of the blood vessels increases the amount of blood and heat that moves near the skins surface. The heat is then released from the skin. This helps you cool down. What do you think your blood vessels do when your body temperature is decreasing? The blood also carries hormones, which are chemical messenger molecules produced by organs of the endocrine system, through your body. Hormones are produced in one area of your body and have an effect on another area. To get to that other area, they must travel through your blood. An example is the hormone adrenaline, produced by the adrenal glands on top of the kidneys. Adrenaline has multiple effects on the heart (it quickens the heart rate), on muscles and on the airway. "
__fist-sized organ that pumps blood,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,F,"The heart is a muscular organ in the chest. It consists mainly of cardiac muscle tissue. It pumps blood by repeated, rhythmic contractions. This produces the familiar lub-dub sound of each heartbeat. For a good video introduction to the heart and how it works, watch this entertaining Bill Nye video:  MEDIA Click image to the left or use the URL below. URL: "
Both the pulmonary and the systemic circulations carry blood,(A) to cells throughout the body (B) through the lungs (C) through the heart (D) two of the above,C,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
__tubular organ that carries blood,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,C,"Blood vessels are long, tube-like organs that consist mainly of muscle, connective, and epithelial tissues. They branch to form a complex network of vessels that run throughout the body. This network transports blood to all the bodys cells. "
__liquid connective tissue,(A) apulmonary circulation (B) bblood (C) cblood vessel (D) dcardiovascular (E) esystemic circulation (F) fheart (G) gtransport,B,Blood is a liquid connective tissue. It circulates throughout the body via blood vessels due to the pumping action of the heart. You couldnt survive without the approximately 4.5 to 5 liters of blood that are constantly being pumped through your blood vessels. 
"Organs of the cardiovascular system include the heart, blood vessels, and lungs.",(A) true (B) false,B,The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure 18.1 shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. 
The cardiovascular system helps maintain homeostasis by regulating body temperature.,(A) true (B) false,A,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
Oxygen-rich blood flows from the heart to the lungs.,(A) true (B) false,B,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
Blood that flows through the systemic circulation never flows through the pulmonary circulation.,(A) true (B) false,B,"The heart and blood vessels form a closed system through which blood keeps circulating. However, blood actually circulates in two different loops within this closed system. The two loops are called pulmonary circulation and systemic circulation. In both loops, blood passes through the heart. You can see a simple model of each circulation loop in Figure 18.2. As blood circulates through the body, it travels first through one loop and then the other loop, over and over again. "
Substances transported by the blood include hormones and nutrients.,(A) true (B) false,A,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
Nutrients are absorbed by the blood mainly in the small intestine.,(A) true (B) false,A,"After food is broken down into nutrient molecules, the molecules are absorbed by the blood. Absorption is the process in which nutrients or other molecules are taken up by the blood. Once absorbed by the blood, nutrients can travel in the bloodstream to cells throughout the body. "
Transport of substances by the cardiovascular system is necessary for homeostasis.,(A) true (B) false,A,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
"When less blood flows to the body surface, it allows the body to lose excess heat.",(A) true (B) false,B,"In hot weather, mammals may need to lose excess body heat. One way they do this is by increasing blood flow to the body surface. The increased blood flow warms the skin, which gives off heat to the environment. Most mammals also sweat to lose excess heat. Sweating wets the skin. Evaporation of the sweat requires heat. The heat comes from the body and cools it down. Animals with fur, like the dogs in Figure 14.12, may pant instead of sweat to lose body heat. Water evaporates from the tongue and other moist surfaces of the mouth, using heat from the body. Watch this video to learn about some unique ways that elephants lose excess heat:  MEDIA Click image to the left or use the URL below. URL: "
The pulmonary and systemic loops of the cardiovascular system are not connected.,(A) true (B) false,B,"The heart and blood vessels form a closed system through which blood keeps circulating. However, blood actually circulates in two different loops within this closed system. The two loops are called pulmonary circulation and systemic circulation. In both loops, blood passes through the heart. You can see a simple model of each circulation loop in Figure 18.2. As blood circulates through the body, it travels first through one loop and then the other loop, over and over again. "
"In the pulmonary circulation, oxygen-poor blood returns to the heart.",(A) true (B) false,B,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
"In the systemic circulation, oxygen-rich blood leaves the heart.",(A) true (B) false,A,"Systemic circulation is the part of the cardiovascular system that carries oxygen-rich blood away from the heart, to the body, and returns oxygen-poor blood back to the heart. Oxygen-rich blood leaves the left ventricle through the aorta. Then it travels to the bodys organs and tissues. The tissues and organs absorb the oxygen through the capillaries. Oxygen-poor blood is collected from the tissues and organs by tiny veins, which then flow into bigger veins, and, eventually, into the inferior vena cava and superior vena cava. This completes systemic circulation. The blood releases carbon dioxide and gets more oxygen in pulmonary circulation before returning to systemic circulation. The inferior vena cava returns blood from the body. The superior vena cava returns blood from the head. "
"As blood flows by body cells, it absorbs cellular waste products from them.",(A) true (B) false,A,"The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the bodys cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood: defends the body against infections. repairs body tissues. controls the bodys pH. helps regulate body temperature. "
The cardiovascular system includes the,(A) heart (B) kidneys (C) lungs (D) all of the above,A,The organs that make up the cardiovascular system are the heart and a network of blood vessels that run throughout the body. The blood in the cardiovascular system is a liquid connective tissue. Figure 18.1 shows the heart and major vessels through which blood flows in the system. The heart is basically a pump that keeps blood moving through the blood vessels. 
Substances carried in the blood include,(A) oxygen (B) nutrients (C) hormones (D) all of the above,D,"Blood consists of both liquid and cells. The liquid part of blood is called plasma. Plasma is a watery, golden-yellow fluid that contains many dissolved substances. Substances dissolved in plasma include glucose, proteins, and gases. Plasma also contains blood cells. There are three types of blood cells: red blood cells, white blood cells, and platelets. You can see all three types in Figure 18.8. 1. Red blood cells are shaped like flattened disks. There are trillions of red blood cells in your blood. Each red blood cell has millions of molecules of hemoglobin. Hemoglobin is a protein that contains iron. The iron in hemoglobin gives red blood cells their red color. It also explains how hemoglobin carries oxygen. The iron in hemoglobin binds with oxygen molecules so they can be carried by red blood cells. 2. White blood cells are larger than red blood cells, but there are far fewer of them. Their role is to defend the body in various ways. For example, white blood cells called phagocytes engulf and destroy microorganisms and debris in the blood. 3. Platelets are small, sticky cell fragments that help blood clot. A blood clot is a solid mass of cell fragments and other substances that plugs a leak in a damaged blood vessel. Platelets stick to tears in blood vessels and to each other, helping to form a clot at the site of injury. Platelets also release chemicals that are needed for clotting to occur. "
The cardiovascular system helps regulate body temperature by,(A) stimulating sweat production (B) increasing the rate of metabolism (C) controlling where blood flows in the body (D) absorbing ultraviolet light through the skin,C,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
Oxygen-poor blood flows from the heart to the,(A) kidneys (B) cells of the body (C) lungs (D) liver,C,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
Oxygen-rich blood flows,(A) through the pulmonary circulation (B) through the systemic circulation (C) from the lungs to the heart (D) all of the above,D,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
"In the lungs, blood",(A) releases carbon dioxide (B) picks up water vapor (C) absorbs nutrients (D) all of the above,A,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
"As blood passes by cells of the body, it",(A) releases oxygen (B) releases carbon dioxide (C) absorbs energy (D) none of the above,A,Blood is a liquid connective tissue. It circulates throughout the body via blood vessels due to the pumping action of the heart. You couldnt survive without the approximately 4.5 to 5 liters of blood that are constantly being pumped through your blood vessels. 
Which blood vessels carry blood away from the heart?,(A) arteries (B) veins (C) venules (D) two of the above,A,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
__disorder that occurs when plaque blocks coronary arteries,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,G,"Diseases of the heart and blood vessels are called cardiovascular diseases. The leading cause of cardiovascular disease is atherosclerosis. Atherosclerosis is a condition in which a material called plaque builds up inside arteries. Plaque consists of cell debris, cholesterol, and other substances. As plaque builds up in an artery, the artery narrows, as shown in Figure If plaque blocks coronary arteries that supply blood to the heart, coronary heart disease results. Poor blood flow to the heart may cause chest pain or a heart attack. A heart attack occurs when the blood supply to part of the heart muscle is completely blocked so that cardiac muscle cells die. Coronary heart disease is the leading cause of death in U.S adults. "
__chamber of the heart that receives oxygen-poor blood from the body,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,A,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
The left atrium of the heart receives blood from the,(A) right ventricle (B) right atrium (C) left ventricle (D) lungs,A,"The heart has four chambers, or rooms, which you can see in Figure 18.3. Each chamber is an empty space with muscular walls through which blood can flow. The top two chambers of the heart are called the left and right atria (atrium, singular). The atria of the heart receive blood from the body or lungs and pump it into the bottom chambers of the heart. The bottom two chambers of the heart are called the left and right ventricles. The ventricles receive blood from the atria and pump it out of the heart, either to the lungs or to the rest of the body. Flaps of tissue called valves separate the hearts chambers. Valves keep blood flowing in just one direction through the heart. For example, a valve at the bottom of the right atrium opens to let blood flow from the right atrium to the right ventricle. Then the valve closes so the blood cant flow back into the right atrium. "
The right ventricle pumps blood to the,(A) left ventricle (B) right atrium (C) right ventricle (D) lungs,A,"What does the heart look like? How does it pump blood? The heart is divided into four chambers ( Figure 1.1), or spaces: the left and right atria, and the left and right ventricles. An atrium (singular for atria) is one of the two small, thin-walled chambers on the top of the heart where the blood first enters. A ventricle is one of the two muscular V-shaped chambers that pump blood out of the heart. You can remember they are called ventricles because they are shaped like a ""V."" The atria receive the blood, and the ventricles pump the blood out of the heart. Each of the four chambers of the heart has a specific job. The right atrium receives oxygen-poor blood from the body. The right ventricle pumps oxygen-poor blood toward the lungs, where it receives oxygen. The left atrium receives oxygen-rich blood from the lungs. The left ventricle pumps oxygen-rich blood out of the heart to the rest of the body. "
__chamber of the heart that pumps blood out of the heart to the rest of the body,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,C,"What does the heart look like? How does it pump blood? The heart is divided into four chambers ( Figure 1.1), or spaces: the left and right atria, and the left and right ventricles. An atrium (singular for atria) is one of the two small, thin-walled chambers on the top of the heart where the blood first enters. A ventricle is one of the two muscular V-shaped chambers that pump blood out of the heart. You can remember they are called ventricles because they are shaped like a ""V."" The atria receive the blood, and the ventricles pump the blood out of the heart. Each of the four chambers of the heart has a specific job. The right atrium receives oxygen-poor blood from the body. The right ventricle pumps oxygen-poor blood toward the lungs, where it receives oxygen. The left atrium receives oxygen-rich blood from the lungs. The left ventricle pumps oxygen-rich blood out of the heart to the rest of the body. "
__chamber of the heart that receives oxygen-rich blood from the lungs,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,F,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
Which blood vessels contain valves?,(A) veins (B) arteries (C) arterioles (D) capillaries,A,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
__event in which blood supply to the heart is blocked so cardiac muscle cells die,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,D,"Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They are known as coronary arteries. Coronary heart disease is the end result of the buildup of plaque within the walls of the coronary arteries. Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain. Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no symptoms for many years until they have a heart attack. A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States. The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the heart muscle to die ( Figure 1.2). Maybe one day stem cells will be used to replace dead cardiac muscle cells. "
Which factors are associated with an increased risk of cardiovascular diseases?,(A) older age (B) female gender (C) low blood pressure (D) two of the above,A,"There are many risk factors that can cause a person to develop cardiovascular disease. A risk factor is anything that is linked to an increased chance of developing a disease. Some of the risk factors for cardiovascular disease you cannot control, but there are many risk factors you can control. Risk factors you cannot control include: Age: The older a person is, the greater their chance of developing a cardiovascular disease. Gender: Men under age 64 are much more likely to die of coronary heart disease than women, although the gender difference decreases with age. Genetics: Family history of cardiovascular disease increases a persons chance of developing heart disease. Risk factors you can control include many lifestyle factors: Tobacco smoking: Giving up smoking or never starting to smoke is the best way to reduce the risk of heart disease. Diabetes: Diabetes can cause bodily changes, such as high cholesterol levels, which are are risk factors for cardiovascular disease. High cholesterol levels: High amounts of ""bad cholesterol,"" increase the risk of cardiovascular disease. Obesity: Having a very high percentage of body fat, especially if the fat is mostly found in the upper body, rather than the hips and thighs, increases risk significantly. High blood pressure: If the heart and blood vessels have to work harder than normal, this puts the cardiovas- cular system under a strain. Lack of physical activity: Aerobic activities, such as the one pictured below ( Figure 1.1), help keep your heart healthy. To reduce the risk of disease, you should be active for at least 60 minutes a day, five days a week. Poor eating habits: Eating mostly foods that do not have many nutrients other than fat or carbohydrate leads to high cholesterol levels, obesity, and cardiovascular disease ( Figure 1.2). 60 minutes a day of vigorous aerobic activity, such as basketball, is enough to help keep your cardiovascular system healthy. "
__chamber of the heart that pumps blood out of the heart to the lungs,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,E,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
__cluster of cells in the heart that control contractions of cardiac muscles,(A) aright atrium (B) bpacemaker (C) cleft ventricle (D) dheart attack (E) eright ventricle (F) fleft atrium (G) gcoronary heart disease,B,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
Blood in the pulmonary circulation passes through the right and left atria.,(A) true (B) false,A,Blood flows through the heart in two paths. Trace these two paths in Figure 18.4 as you read about them below. You can also learn about how blood flows through the heart with this rap:  MEDIA Click image to the left or use the URL below. URL:  1. One path of blood in the heart is through the right atrium and right ventricle. The right atrium receives oxygen- poor blood from the body. It pumps the blood into the right ventricle. Then the right ventricle pumps the blood out of the heart to the lungs. This path through the heart is part of the pulmonary circulation. 2. The other path of blood in the heart is through the left atrium and left ventricle. The left atrium receives oxygen-rich blood from the lungs. It pumps the blood into the left ventricle. Then the left ventricle pumps the blood out of the heart to the rest of the body. This path through the heart is part of the systemic circulation. 
"Each time the heart beats, the ventricles contract first, followed by the atria.",(A) true (B) false,B,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
Veins must have muscular walls to withstand the pressure of blood pumped by the heart.,(A) true (B) false,B,"The health of your whole body depends on the good health of your cardiovascular system. One measure of the health of your cardiovascular system is blood pressure. Blood pressure occurs when circulating blood puts pressure on the walls of blood vessels. Since blood pressure is primarily caused by the beating of your heart, the walls of the arteries move in a rhythmic fashion. Blood in arteries is under the greatest amount of pressure. The pressure of the circulating blood slowly decreases as blood moves from the arteries and into the smaller blood vessels. Blood in veins is not under much pressure. "
Arteries generally carry oxygen-rich blood.,(A) true (B) false,A,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
"When blood vessels dilate, it increases the amount of blood they can carry.",(A) true (B) false,A,"Blood vessels help regulate body processes by either dilating (widening) or constricting (narrowing). This changes the amount of blood flowing to particular organs. For example, dilation of blood vessels in the skin allows more blood to flow to the surface of the body. This helps the body lose excess heat. Constriction of these blood vessels has the opposite effect and helps the body conserve heat. "
Blood in an atrium always flows next to,(A) a ventricle (B) an artery (C) the lungs (D) a vein,A,Blood flows through the heart in two paths. Trace these two paths in Figure 18.4 as you read about them below. You can also learn about how blood flows through the heart with this rap:  MEDIA Click image to the left or use the URL below. URL:  1. One path of blood in the heart is through the right atrium and right ventricle. The right atrium receives oxygen- poor blood from the body. It pumps the blood into the right ventricle. Then the right ventricle pumps the blood out of the heart to the lungs. This path through the heart is part of the pulmonary circulation. 2. The other path of blood in the heart is through the left atrium and left ventricle. The left atrium receives oxygen-rich blood from the lungs. It pumps the blood into the left ventricle. Then the left ventricle pumps the blood out of the heart to the rest of the body. This path through the heart is part of the systemic circulation. 
"In the pulmonary circulation, blood flows through the",(A) right atrium (B) right ventricle (C) lungs (D) all of the above,D,"Pulmonary circulation is the shorter loop of the cardiovascular system. It carries blood between the heart and lungs. Oxygen-poor blood flows from the heart to the lungs. In the lungs, the blood absorbs oxygen and releases carbon dioxide. Then the oxygen-rich blood returns to the heart. "
The pacemaker controls the beating of the heart with,(A) enzymes (B) hormones (C) electrical signals (D) valves,C,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
Tissues that make up blood vessels include,(A) muscle tissues (B) connective tissues (C) epithelial tissues (D) all of the above,D,"Blood vessels are long, tube-like organs that consist mainly of muscle, connective, and epithelial tissues. They branch to form a complex network of vessels that run throughout the body. This network transports blood to all the bodys cells. "
Muscular blood vessels that generally carry oxygen-rich blood are,(A) veins (B) arteries (C) capillaries (D) venules,B,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
The largest vein in the body is the,(A) aorta (B) arteriole (C) inferior vena cava (D) none of the above,C,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
Which statement about capillaries is false?,(A) The walls of capillaries may be just one cell thick (B) Capillaries connect arterioles and venules (C) The exchange of substances between cells and the blood takes place across capillary walls (D) Capillaries contain valves to prevent the backflow of blood,D,"There are three major types of blood vessels: arteries, veins, and capillaries. You can see each type in Figure 18.5. You can watch a good video introduction to the three types at this link:  MEDIA Click image to the left or use the URL below. URL:  Arteries are muscular blood vessels that carry blood away from the heart. They have thick walls that can withstand the pressure of blood pumped by the heart. Arteries generally carry oxygen-rich blood. The largest artery is the aorta, which receives blood directly from the heart. It branches to form smaller and smaller arteries throughout the body. The smallest arteries are called arterioles. Veins are blood vessels that carry blood toward the heart. This blood is no longer under pressure, so veins have thinner walls. To keep the blood moving, many veins have valves that prevent the backflow of blood. Veins generally carry oxygen-poor blood. The smallest veins are called venules. They merge to form larger and larger veins. The largest vein is the inferior vena cava, which carries blood from the lower body directly to the heart. Capillaries are the smallest type of blood vessels. They connect the smallest arteries (arterioles) and veins (venules). Exchange of substances between cells and the blood takes place across the walls of capillaries, which may be only one cell thick. "
Blood flows through the heart in two paths,(A) true (B) false,A,Blood flows through the heart in two paths. Trace these two paths in Figure 18.4 as you read about them below. You can also learn about how blood flows through the heart with this rap:  MEDIA Click image to the left or use the URL below. URL:  1. One path of blood in the heart is through the right atrium and right ventricle. The right atrium receives oxygen- poor blood from the body. It pumps the blood into the right ventricle. Then the right ventricle pumps the blood out of the heart to the lungs. This path through the heart is part of the pulmonary circulation. 2. The other path of blood in the heart is through the left atrium and left ventricle. The left atrium receives oxygen-rich blood from the lungs. It pumps the blood into the left ventricle. Then the left ventricle pumps the blood out of the heart to the rest of the body. This path through the heart is part of the systemic circulation. 
A valve prevents blood from flowing from a ventricle to an atrium.,(A) true (B) false,A,"Blood flows through the heart in two separate loops. You can think of them as a left side loop and a right side loop. The right side of the heart collects oxygen-poor blood from the body and pumps it into the lungs, where it releases carbon dioxide and picks up oxygen. (Recall that carbon dioxide is a waste product that must be removed. It is removed when we exhale.) The left side carries the oxygen-rich blood back from the lungs into the left side of the heart, which then pumps the oxygen-rich blood to the rest of the body. The blood delivers oxygen to the cells of the body, where it is needed for cellular respiration, and returns to the heart oxygen-poor. To move blood through the heart, the cardiac muscle needs to contract in an organized way. Blood first enters the atria ( Figure 1.2). When the atria contract, blood is pushed into the ventricles. After the ventricles fill with blood, they contract, and blood is pushed out of the heart. The heart is mainly composed of cardiac muscle. These muscle cells contract in unison, causing the heart itself to contract and generating enough force to push the blood out. So how is the blood kept from flowing back on itself? Valves ( Figure 1.2) in the heart keep the blood flowing in one direction. The valves do this by opening and closing in one direction only. Blood only moves forward through the heart. The valves stop the blood from flowing backward. There are four valves of the heart. The two atrioventricular (AV) valves stop blood from moving from the ventricles to the atria. The two semilunar (SL) valves are found in the arteries leaving the heart, and they prevent blood from flowing back from the arteries into the ventricles. Why does a heart beat? The lub-dub sound of the heartbeat is caused by the closing of the AV valves (""lub"") and SL valves (""dub"") after blood has passed through them. "
The systemic circulation includes the right atrium and right ventricle.,(A) true (B) false,B,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
The aorta is a large blood vessel that carries blood to the heart.,(A) true (B) false,B,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
Veins have thicker walls than arteries.,(A) true (B) false,B,"There are three major types of blood vessels: arteries, veins, and capillaries. You can see each type in Figure 18.5. You can watch a good video introduction to the three types at this link:  MEDIA Click image to the left or use the URL below. URL:  Arteries are muscular blood vessels that carry blood away from the heart. They have thick walls that can withstand the pressure of blood pumped by the heart. Arteries generally carry oxygen-rich blood. The largest artery is the aorta, which receives blood directly from the heart. It branches to form smaller and smaller arteries throughout the body. The smallest arteries are called arterioles. Veins are blood vessels that carry blood toward the heart. This blood is no longer under pressure, so veins have thinner walls. To keep the blood moving, many veins have valves that prevent the backflow of blood. Veins generally carry oxygen-poor blood. The smallest veins are called venules. They merge to form larger and larger veins. The largest vein is the inferior vena cava, which carries blood from the lower body directly to the heart. Capillaries are the smallest type of blood vessels. They connect the smallest arteries (arterioles) and veins (venules). Exchange of substances between cells and the blood takes place across the walls of capillaries, which may be only one cell thick. "
One way that blood vessels help maintain homeostasis is by dilating or constricting.,(A) true (B) false,A,"Blood vessels help regulate body processes by either dilating (widening) or constricting (narrowing). This changes the amount of blood flowing to particular organs. For example, dilation of blood vessels in the skin allows more blood to flow to the surface of the body. This helps the body lose excess heat. Constriction of these blood vessels has the opposite effect and helps the body conserve heat. "
The leading cause of cardiovascular disease is atherosclerosis.,(A) true (B) false,A,"Diseases of the heart and blood vessels are called cardiovascular diseases. The leading cause of cardiovascular disease is atherosclerosis. Atherosclerosis is a condition in which a material called plaque builds up inside arteries. Plaque consists of cell debris, cholesterol, and other substances. As plaque builds up in an artery, the artery narrows, as shown in Figure If plaque blocks coronary arteries that supply blood to the heart, coronary heart disease results. Poor blood flow to the heart may cause chest pain or a heart attack. A heart attack occurs when the blood supply to part of the heart muscle is completely blocked so that cardiac muscle cells die. Coronary heart disease is the leading cause of death in U.S adults. "
Blood plasma is a,(A) chemical that helps blood clot (B) golden-yellow liquid in blood (C) disorder in which the blood lacks oxygen (D) protein carried by red blood cells,B,"If you were to filter out all the cells in blood, a golden-yellow liquid would be left behind. Plasma is this fluid part of the blood. Plasma is about 90% water and about 10% dissolved proteins, glucose, ions, hormones, and gases. Blood is made up mostly of plasma. "
Plasma carries dissolved substances such as glucose and proteins.,(A) true (B) false,A,"If you were to filter out all the cells in blood, a golden-yellow liquid would be left behind. Plasma is this fluid part of the blood. Plasma is about 90% water and about 10% dissolved proteins, glucose, ions, hormones, and gases. Blood is made up mostly of plasma. "
There are more white blood cells than red blood cells in normal blood.,(A) true (B) false,B,"White blood cells (WBCs) are usually larger than red blood cells. They do not have hemoglobin and do not carry oxygen. White blood cells make up less than one percent of the bloods volume. Most WBCs are made in the bone marrow, and some mature in the lymphatic system. There are different WBCs with different jobs. WBCs defend the body against infection by bacteria, viruses, and other pathogens. WBCs do have a nucleus and other organelles. Neutrophils are WBCs that can squeeze through capillary walls and swallow particles such as bacteria and parasites. Macrophages are large WBCs that can also swallow and destroy old and dying cells, bacteria, or viruses. Below, a macrophage is attacking and swallowing two particles, possibly disease-causing pathogens ( Figure Lymphocytes are WBCs that fight infections caused by viruses and bacteria. Some lymphocytes attack and kill cancer cells. Lymphocytes called B-cells make antibodies. A type of white blood cell, called a macrophage, is attacking a cancer cell. "
Which statement about red blood cells is false?,(A) They are spherical in shape (B) There are trillions of them in normal blood (C) They contain iron (D) none of the above,A,"Red blood cells (RBCs) are flattened, disk-shaped cells that carry oxygen. They are the most common blood cell in the blood. There are about 4 to 6 million RBCs per cubic millimeter of blood. Each RBC has about 200 million molecules of hemoglobin. Hemoglobin is the protein that carries oxygen. Hemoglobin also gives the red blood cells their red color. Red blood cells ( Figure 1.2) are made in the red marrow of long bones, rib bones, the skull, and vertebrae. Each red blood cell lives for only 120 days (about four months). After this time, they are destroyed in the liver and spleen. Mature red blood cells do not have a nucleus or other organelles. Lacking these components allows the cells to have more hemoglobin and carry more oxygen. The flattened shape of red blood cells helps them carry more oxygen than if they were rounded. "
What are phagocytes?,(A) cell fragments that form blood clots (B) white blood cells that engulf microorganisms (C) proteins that bind with oxygen in the blood (D) molecules that determine blood type,B,The white blood cells that go to a site of inflammation and leak into damaged tissue are called phagocytes. They start eating pathogens and dead cells by engulfing and destroying them. This process is called phagocytosis. You can see how it happens in Figure ??. You can see it in action in the animation at this link: http://commons.wikim 
Phagocytes are cells that help form blood clots.,(A) true (B) false,B,The white blood cells that go to a site of inflammation and leak into damaged tissue are called phagocytes. They start eating pathogens and dead cells by engulfing and destroying them. This process is called phagocytosis. You can see how it happens in Figure ??. You can see it in action in the animation at this link: http://commons.wikim 
The main function of blood is transport.,(A) true (B) false,A,"The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the bodys cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood: defends the body against infections. repairs body tissues. controls the bodys pH. helps regulate body temperature. "
All of the following are normal functions of blood except,(A) controlling the bodys pH (B) repairing body tissues (C) helping regulate body temperature (D) causing agglutination,D,"The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the bodys cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood: defends the body against infections. repairs body tissues. controls the bodys pH. helps regulate body temperature. "
Your ABO blood type is controlled by genes you get from your parents.,(A) true (B) false,A,"Red blood cells carry proteins called antigens on their surface. People may vary in the exact antigens their red blood cells carry. The specific proteins are controlled by the genes they inherit from their parents. The particular antigens you inherit determine your blood type. Why does your blood type matter? Blood type is important for medical reasons. A patient cant safely receive a transfusion of blood containing antigens not found in the patients own blood. With foreign antigens, the transfused blood will be rejected by the persons immune system. This causes a reaction in the patients bloodstream, called agglutination. The transfused red blood cells clump together, as shown in Figure 18.9. The clumped cells block blood vessels and cause other life-threatening problems. There are many sets of antigens that determine different blood types. Two of the best known are the ABO and Rhesus antigens. Both are described below. You can also learn more about them by watching this video: "
Which disease of the blood is a form of cancer?,(A) hemophilia (B) anemia (C) leukemia (D) sickle-cell disease,C,"Blood cancers affect the production and function of your blood cells. Most of these cancers start in your bone marrow where blood is produced. In most blood cancers, the normal production of blood cells is replaced by uncontrolled growth of an abnormal type of blood cell. These abnormal blood cells are cancerous cells, and prevent your blood from performing many of its functions, like fighting off infections or preventing serious bleeding. Leukemia is a cancer of the blood or bone marrow. It is characterized by an abnormal production of blood cells, usually white blood cells. Lymphoma is a cancer of a type of white blood cell called lymphocytes. There are many types of lymphoma. "
One cause of anemia is lack of iron in the diet.,(A) true (B) false,A,Anemia is a disease that occurs when there is not enough hemoglobin (or iron) in the blood so it cant carry adequate oxygen to the cells. There are many possible causes of anemia. One possible cause is excessive blood loss due to an injury or surgery. Not getting enough iron in the diet is another possible cause. 
Hemophilia is more common in females than in males.,(A) true (B) false,B,"Hemophilia is a genetic disorder in which blood fails to clot properly because a normal clotting factor in the blood is lacking. In people with hemophilia, even a minor injury can cause a life-threatening loss of blood. Most cases of hemophilia are caused by a recessive gene on the X chromosome. The disorder is expressed much more commonly in males because they have just one X chromosome. "
__solid mass of cell fragments and other substances that plugs a leak in a blood vessel,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,D,"Platelets ( Figure 1.4) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. "
__condition in which blood does not have enough hemoglobin (or iron) to carry adequate oxygen to,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,E,Anemia is a disease that occurs when there is not enough hemoglobin (or iron) in the blood so it cant carry adequate oxygen to the cells. There are many possible causes of anemia. One possible cause is excessive blood loss due to an injury or surgery. Not getting enough iron in the diet is another possible cause. 
__type of cancer in which bone marrow produces abnormal white blood cells,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,G,"Leukemia is a type of cancer in which bone marrow produces abnormal white blood cells. The abnormal cells cant do their job of fighting infections. Like most cancers, leukemia is thought to be caused by a combination of genetic and environmental factors. It is the most common cancer in children. "
__genetic disorder in which abnormal hemoglobin causes red blood cells to change shape,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,C,"Sickle-Cell Disease is another genetic disorder of the blood. It is more common in people with African origins because it helps protect against malaria. Sickle-cell disease occurs in people who inherit two copies of the recessive mutant gene for hemoglobin. The abnormal hemoglobin that results causes red blood cells to take on a characteristic sickle shape under certain conditions. You can compare sickle-shaped and normal red blood cells in Figure 18.10. The sickle-shaped cells get stuck in tiny capillaries and block blood flow. This causes serious, painful symptoms. Watch this video animation to learn more about the genetic basis of sickle-cell disease: "
The cardiovascular system normally contains about 2.5 liters of blood.,(A) true (B) false,B,Blood is a liquid connective tissue. It circulates throughout the body via blood vessels due to the pumping action of the heart. You couldnt survive without the approximately 4.5 to 5 liters of blood that are constantly being pumped through your blood vessels. 
Antigens on your red blood cells determine your blood type.,(A) true (B) false,A,"Another red blood cell antigen determines a persons Rhesus blood type. This blood type depends on a single common antigen, typically referred to as the Rhesus (Rh) antigen. If your red blood cells carry the Rhesus antigen, you have Rhesus-positive blood, or blood type Rh+. If your red blood cells lack the Rhesus antigen, you have Rhesus-negative blood, or blood type Rh-. "
"__small, sticky cell fragment that helps blood clot",(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,F,"Platelets ( Figure 1.4) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. "
Dissolved substances in blood include red and white blood cells.,(A) true (B) false,B,"Blood consists of both liquid and cells. The liquid part of blood is called plasma. Plasma is a watery, golden-yellow fluid that contains many dissolved substances. Substances dissolved in plasma include glucose, proteins, and gases. Plasma also contains blood cells. There are three types of blood cells: red blood cells, white blood cells, and platelets. You can see all three types in Figure 18.8. 1. Red blood cells are shaped like flattened disks. There are trillions of red blood cells in your blood. Each red blood cell has millions of molecules of hemoglobin. Hemoglobin is a protein that contains iron. The iron in hemoglobin gives red blood cells their red color. It also explains how hemoglobin carries oxygen. The iron in hemoglobin binds with oxygen molecules so they can be carried by red blood cells. 2. White blood cells are larger than red blood cells, but there are far fewer of them. Their role is to defend the body in various ways. For example, white blood cells called phagocytes engulf and destroy microorganisms and debris in the blood. 3. Platelets are small, sticky cell fragments that help blood clot. A blood clot is a solid mass of cell fragments and other substances that plugs a leak in a damaged blood vessel. Platelets stick to tears in blood vessels and to each other, helping to form a clot at the site of injury. Platelets also release chemicals that are needed for clotting to occur. "
__classification of an individuals blood based on its red blood cell antigens,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,A,"Another red blood cell antigen determines a persons Rhesus blood type. This blood type depends on a single common antigen, typically referred to as the Rhesus (Rh) antigen. If your red blood cells carry the Rhesus antigen, you have Rhesus-positive blood, or blood type Rh+. If your red blood cells lack the Rhesus antigen, you have Rhesus-negative blood, or blood type Rh-. "
__genetic disorder in which blood is lacking a normal clotting factor,(A) ablood type (B) bhemophilia (C) csickle-cell disease (D) dblood clot (E) eanemia (F) fplatelet (G) gleukemia,B,"Hemophilia is a genetic disorder in which blood fails to clot properly because a normal clotting factor in the blood is lacking. In people with hemophilia, even a minor injury can cause a life-threatening loss of blood. Most cases of hemophilia are caused by a recessive gene on the X chromosome. The disorder is expressed much more commonly in males because they have just one X chromosome. "
One cause of anemia is excessive loss of blood due to injury or surgery.,(A) true (B) false,A,Anemia is a disease that occurs when there is not enough hemoglobin (or iron) in the blood so it cant carry adequate oxygen to the cells. There are many possible causes of anemia. One possible cause is excessive blood loss due to an injury or surgery. Not getting enough iron in the diet is another possible cause. 
Blood in veins carries oxygen and nutrients to all the cells of the body.,(A) true (B) false,B,"The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the bodys cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood: defends the body against infections. repairs body tissues. controls the bodys pH. helps regulate body temperature. "
How much blood does your cardiovascular system normally contain?,(A) 3540 liters (B) 4550 liters (C) 5560 liters (D) 6570 liters,B,Blood is a liquid connective tissue. It circulates throughout the body via blood vessels due to the pumping action of the heart. You couldnt survive without the approximately 4.5 to 5 liters of blood that are constantly being pumped through your blood vessels. 
Blood consists of,(A) plasma (B) cells and cell fragments (C) dissolved substances (D) all of the above,D,"Blood consists of both liquid and cells. The liquid part of blood is called plasma. Plasma is a watery, golden-yellow fluid that contains many dissolved substances. Substances dissolved in plasma include glucose, proteins, and gases. Plasma also contains blood cells. There are three types of blood cells: red blood cells, white blood cells, and platelets. You can see all three types in Figure 18.8. 1. Red blood cells are shaped like flattened disks. There are trillions of red blood cells in your blood. Each red blood cell has millions of molecules of hemoglobin. Hemoglobin is a protein that contains iron. The iron in hemoglobin gives red blood cells their red color. It also explains how hemoglobin carries oxygen. The iron in hemoglobin binds with oxygen molecules so they can be carried by red blood cells. 2. White blood cells are larger than red blood cells, but there are far fewer of them. Their role is to defend the body in various ways. For example, white blood cells called phagocytes engulf and destroy microorganisms and debris in the blood. 3. Platelets are small, sticky cell fragments that help blood clot. A blood clot is a solid mass of cell fragments and other substances that plugs a leak in a damaged blood vessel. Platelets stick to tears in blood vessels and to each other, helping to form a clot at the site of injury. Platelets also release chemicals that are needed for clotting to occur. "
How does blood carry oxygen molecules?,(A) Iron in hemoglobin binds with them (B) White blood cells engulf them (C) Platelets stick to them (D) none of the above,A,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
What does blood in veins carry?,(A) oxygen (B) carbon dioxide (C) cellular wastes (D) two of the above,D,"The main function of blood is transport. Blood in arteries carries oxygen and nutrients to all the bodys cells. Blood in veins carries carbon dioxide and other wastes away from cells to be excreted. Blood also transports the chemical messengers called hormones to cells throughout the body where they are needed to regulate body functions. Blood has several other functions as well. For example, blood: defends the body against infections. repairs body tissues. controls the bodys pH. helps regulate body temperature. "
Which genotype produces blood type A?,(A) AO (B) AB (C) OO (D) none of the above,A,"Another exception to Mendels laws is a phenomenon called codominance. For example, our blood type shows codominance. Do you know what your blood type is? Are you A? O? AB? Those letters actually represent alleles. Unlike other traits, your blood type has three alleles, instead of two! The ABO blood types ( Figure 1.3) are named for the protein attached to the outside of the blood cell. In this case, two alleles are dominant and completely expressed (IA and IB ), while one allele is recessive (i). The IA allele encodes for red blood cells with the A antigen, while the IB allele encodes for red blood cells with the B antigen. The recessive allele (i) does not encode for any proteins. Therefore a person with two recessive alleles (ii) has type O blood. As no dominant (IA and IB ) allele is present, the person cannot have type A or type B blood. What are the genotypes of a person with type A or type B blood? An example of codominant inheritance is ABO blood types. There are two possible genotypes for type A blood, homozygous (IA IA ) and heterozygous (IA i), and two possible genotypes for type B blood, (IB IB and IB i). If a person is heterozygous for both the IA and IB alleles, they will express both and have type AB blood with both proteins on each red blood cell. This pattern of inheritance is significantly different than Mendels rules for inheritance, because both alleles are expressed completely, and one does not mask the other. "
The blood of a person with leukemia cannot,(A) carry enough oxygen (B) fight infections (C) clot normally (D) two of the above,B,"Blood cancers affect the production and function of your blood cells. Most of these cancers start in your bone marrow where blood is produced. In most blood cancers, the normal production of blood cells is replaced by uncontrolled growth of an abnormal type of blood cell. These abnormal blood cells are cancerous cells, and prevent your blood from performing many of its functions, like fighting off infections or preventing serious bleeding. Leukemia is a cancer of the blood or bone marrow. It is characterized by an abnormal production of blood cells, usually white blood cells. Lymphoma is a cancer of a type of white blood cell called lymphocytes. There are many types of lymphoma. "
A person with sickle-cell hemoglobin is resistant to,(A) blood clots (B) heart disease (C) malaria (D) hemophilia,C,"Sickle-cell anemia is a blood disease that is caused by an abnormally shaped hemoglobin protein in red blood cells. Many of the red blood cells of a person with sickle-cell anemia are long and curved (sickle-shaped) ( Figure 1.1). The long, sickle shape of the cells can cause them to get stuck in narrow blood vessels. This clotting means that oxygen cannot reach the cells. People with sickle-cell anemia are most often well but can occasionally have painful attacks. The disease is not curable, but it can be treated with medicines. The red blood cells of a person with sickle-cell anemia (left) are long and pointed, rather than straight, like normal cells (right). The abnormal cells cannot carry oxygen properly and can get stuck in capillaries. "
"When you inhale, air passes from your pharynx to your",(A) bronchioles (B) trachea (C) larynx (D) bronchi,C,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
"When you exhale, why does carbon dioxide diffuse from the blood into the air in the lungs?",(A) Carbon dioxide is more concentrated in the blood than in the air (B) Carbon dioxide is forced out of the blood by blood pressure (C) Carbon dioxide is pushed out of the blood by the diaphragm (D) none of the above,A,"The cells of the body have a lower concentration of oxygen that does blood in the capillaries that supply body cells. Therefore, oxygen diffuses from the blood into the cells. Carbon dioxide, which cells produce in cellular respiration, is more concentrated in the cells. Therefore, carbon dioxide diffuses out of the cells and into the blood. The carbon dioxide travels in capillaries to veins and then to the heart. The heart pumps the blood to the lungs, where the carbon dioxide diffuses into the alveoli. It passes out of the body during exhalation. This brings the process of respiration full circle. "
Smoking causes or makes you more susceptible to,(A) asthma (B) emphysema (C) lung cancer (D) all of the above,D,"Cigarette smoking can cause serious diseases, so not smoking or quitting now are the most effective ways to reduce your risk of developing chronic respiratory diseases, such as lung cancer. Avoiding (or stopping) smoking is the single best way to prevent many respiratory and cardiovascular diseases. Also, do your best to avoid secondhand smoke. "
Cellular respiration depends on respiration because cellular respiration,(A) produces oxygen (B) requires glucose (C) requires carbon dioxide (D) none of the above,D,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
Inhaling occurs when the,(A) size of the chest increases (B) diaphragm relaxes (C) air pressure in the lungs increases (D) two of the above,A,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
Gas exchange occurs twice during the process of respiration.,(A) true (B) false,A,"The bodys exchange of oxygen and carbon dioxide with the air is called respiration. Respiration actually consists of two stages. In one stage, air is taken into the body and carbon dioxide is released to the outside air. In the other stage, oxygen is delivered to all the cells of the body and carbon dioxide is carried away from the cells. Another kind of respiration takes place within body cells. This kind of respiration is called cellular respiration. Its the process in which cells obtain energy by burning glucose. Both types of respiration are connected. Cellular respiration uses oxygen and produces carbon dioxide. Respiration by the respiratory system supplies the oxygen needed for cellular respiration. It also removes the carbon dioxide produced by cellular respiration. "
Air is inhaled when the diaphragm relaxes.,(A) true (B) false,B,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
Cilia in the bronchi sweep mucus and particles toward the alveoli.,(A) true (B) false,B,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
Each alveolus is surrounded by a network of capillaries.,(A) true (B) false,A,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
The lungs are the main organs of the respiratory system.,(A) true (B) false,A,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
"When the diaphragm contracts, air flows out of the lungs.",(A) true (B) false,B,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
"When you inhale, oxygen is more concentrated in the blood than in the air inside alveoli.",(A) true (B) false,B,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
Pneumonia may be caused by an infection or an injury to the lungs.,(A) true (B) false,A,"Pneumonia is an illness that occurs when the alveoli, the tiny sacs in the lungs where gas exchange takes place, become inflamed and filled with fluid. When a person has pneumonia, gas exchange cannot occur properly across the alveoli. Pneumonia can be caused by many things. Infection by bacteria, viruses, fungi, or parasites can cause pneumonia. An injury caused by chemicals or a physical injury to the lungs can also cause pneumonia. Symptoms of pneumonia include cough, chest pain, fever, and difficulty breathing. Treatment depends on the cause of pneumonia. Bacterial pneumonia is treated with antibiotics. Pneumonia is a common illness that affects people in all age groups. It is a leading cause of death among the elderly and people who are chronically and terminally ill. "
"When you exhale, carbon dioxide diffuses out of the blood into the air in the alveoli.",(A) true (B) false,A,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
"In some people, asthma attacks may be triggered by strenuous exercise.",(A) true (B) false,A,"Asthma is a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become inflamed and narrow ( Figure 1.2). The muscles around the bronchioles contract, which narrows the airways. Large amounts of mucus are also made by the cells in the lungs. People with asthma have difficulty breathing. Their chests feel tight, and they wheeze. Asthma can be caused by different things, such as allergies. Asthma can also be caused by cold air, warm air, moist air, exercise, or stress. The most common asthma triggers are illnesses, like the common cold. Asthma is not contagious and cannot be passed on to other people. Children and adolescents who have asthma can still lead active lives if they control their asthma. Asthma can be controlled by taking medication and by avoiding contact with environmental triggers for asthma, like smoking. "
Particles in air are trapped by hairs in the nose and cilia in the bronchi.,(A) true (B) false,A,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
"During an asthma attack, the bronchioles widen and produce less mucus.",(A) true (B) false,B,"Asthma is a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become inflamed and narrow ( Figure 1.2). The muscles around the bronchioles contract, which narrows the airways. Large amounts of mucus are also made by the cells in the lungs. People with asthma have difficulty breathing. Their chests feel tight, and they wheeze. Asthma can be caused by different things, such as allergies. Asthma can also be caused by cold air, warm air, moist air, exercise, or stress. The most common asthma triggers are illnesses, like the common cold. Asthma is not contagious and cannot be passed on to other people. Children and adolescents who have asthma can still lead active lives if they control their asthma. Asthma can be controlled by taking medication and by avoiding contact with environmental triggers for asthma, like smoking. "
__tiny air sac in the lungs where gas exchange takes place,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,D,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
"__large, sheet-like muscle below the lungs needed for normal breathing",(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,F,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
__voice box,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,A,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
__process of moving air into and out of the lungs,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,G,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
__process in which cells obtain energy by burning glucose,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,B,"Your own body cells burn fuel in combustion reactions. The fuel is glucose (C6 H12 O6 ), a simple sugar. The process in which combustion of glucose occurs in body cells is called cellular respiration. This combustion reaction provides energy for life processes. Cellular respiration can be summed up by the equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O Where does glucose come from? It is produced by plants during photosynthesis. In this process, carbon dioxide and water combine to form glucose. Which type of chemical reaction is photosynthesis? "
__one of two passages that carry air between the trachea and bronchioles,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,C,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
__wind pipe,(A) alarynx (B) bcellular respiration (C) cbronchus (D) dalveolus (E) etrachea (F) fdiaphragm (G) gbreathing,E,"On the windswept tarmac of the former Alameda Naval Air Station, an inventive group of scientists and engineers are test-flying a kite-like tethered wing that may someday help revolutionize clean energy. QUEST explores the potential of wind energy and new airborne wind turbines designed to harness the stronger and more consistent winds found at higher altitudes. For more information on wind energy, see http://science.kqed.org/quest/video/airborne MEDIA Click image to the left or use the URL below. URL: "
What happens during respiration?,(A) breathing (B) gas exchange between air and blood (C) gas transport by blood (D) all of the above,D,"The bodys exchange of oxygen and carbon dioxide with the air is called respiration. Respiration actually consists of two stages. In one stage, air is taken into the body and carbon dioxide is released to the outside air. In the other stage, oxygen is delivered to all the cells of the body and carbon dioxide is carried away from the cells. Another kind of respiration takes place within body cells. This kind of respiration is called cellular respiration. Its the process in which cells obtain energy by burning glucose. Both types of respiration are connected. Cellular respiration uses oxygen and produces carbon dioxide. Respiration by the respiratory system supplies the oxygen needed for cellular respiration. It also removes the carbon dioxide produced by cellular respiration. "
How is respiration related to cellular respiration?,(A) Respiration supplies the oxygen needed for cellular respiration (B) Respiration provides the glucose burned during cellular respiration (C) Respiration removes the carbon dioxide produced by cellular respiration (D) two of the above,D,"Cellular Respiration is the process in which the cells of living things break down the organic compound glucose with oxygen to produce carbon dioxide and water. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2  6CO2 + 6H2 O As the Figure 1.1 shows, cellular respiration occurs in the cells of all kinds of organisms, including those that make their own food (autotrophs) as well as those that get their food by consuming other organisms (heterotrophs). Q: How is cellular respiration related to breathing? A: Breathing consists of inhaling and exhaling, and its purpose is to move gases into and out of the body. Oxygen needed for cellular respiration is brought into the body with each inhalation. Carbon dioxide and water vapor produced by cellular respiration are released from the body with each exhalation. "
"When you inhale through your nose, which organ does the air pass through next?",(A) larynx (B) trachea (C) bronchiole (D) pharynx,D,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
What happens when the diaphragm contracts?,(A) The size of the chest decreases (B) Air pressure inside the lungs increases (C) Air rushes into the lungs (D) two of the above,C,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
Why does oxygen pass into cells from the blood of capillaries?,(A) Oxygen diffuses down a concentration gradient from the blood to cells (B) Oxygen is carried into cells from the blood by active transport (C) Oxygen is forced into cells from the blood by blood pressure (D) none of the above,A,"Breathing is only part of the process of bringing oxygen to where it is needed in the body. After oxygen enters the lungs, what happens? 1. The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place ( Figure 1.1). The transfer of oxygen into the blood is through simple diffusion. 2. The oxygen-rich blood returns to the heart. 3. Oxygen-rich blood is then pumped through the aorta, the large artery that receives blood directly from the heart. 4. From the aorta, oxygen-rich blood travels to the smaller arteries and, finally, to the capillaries, the smallest type of blood vessel. 5. The oxygen molecules move, by diffusion, out of the capillaries and into the body cells. 6. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries. Gas exchange is the movement of oxygen into the blood and carbon dioxide out of the blood. 7. Carbon dioxide is brought, through the blood, back to the heart and then to the lungs. Then it is released into the air during exhalation. Why is oxygen needed by each cell in your body? To make ATP, the usable form of cellular energy. Oxygen is needed in the final stage of cellular respiration, which is the process of converting glucose into ATP. This process is much more efficient in the presence of oxygen. Without oxygen, much less ATP is produced. As ATP is needed for the cells to function properly, every cell in your body needs oxygen. Getting that oxygen begins with inhaling. The oxygen moves into your blood, where it travels to every cell in your body. "
The main symptom of emphysema is,(A) coughing (B) chest pain (C) chest tightness (D) shortness of breath,D,"Emphysema is a chronic lung disease caused by the breakdown of the lung tissue. Symptoms of emphysema include shortness of breath, especially during exercise, and chronic cough, usually due to cigarette smoking, and wheezing, especially during expiration. Damage to the alveoli ( Figure 1.5), is not curable. Smoking is the leading cause of emphysema. "
Bronchioles connect the,(A) bronchi and alveoli (B) trachea and bronchi (C) larynx and trachea (D) none of the above,A,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
The lungs are part of the respiratory system and the,(A) digestive system (B) urinary system (C) excretory system (D) muscular system,C,"You can see the main structures of the respiratory system in Figure 19.1. They include the nose, trachea, lungs, and diaphragm. Use the figure to trace how air moves through the respiratory system when you read about it below. You can also use this interactive to explore the respiratory system and see how it functions: http://science.nationalgeogr "
Organs of excretion include the large intestine and sweat glands in the skin.,(A) true (B) false,A,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
Blood containing wastes enters each kidney through a ureter.,(A) true (B) false,B,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
The part of a nephron that filters blood is the,(A) urethra (B) tubule (C) glomerulus (D) urinary bladder,C,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
Blood containing wastes enters the kidneys through,(A) ureters (B) veins (C) arteries (D) sphincters,C,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
All of the water filtered out of the blood in the kidneys is excreted in urine.,(A) true (B) false,B,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
The process of urination is normally under conscious control.,(A) true (B) false,A,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
Hormones secreted by the kidneys help regulate,(A) blood pressure (B) the production of white blood cells (C) blood clotting (D) two of the above,A,"The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. For example, they produce a hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete a hormone that regulates blood pressure and keeps it in a normal range. "
The kidneys filter all of the blood in the body once a day.,(A) true (B) false,B,"The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. For example, they produce a hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete a hormone that regulates blood pressure and keeps it in a normal range. "
What does a hemodialysis machine do?,(A) It controls blood sugar in people with diabetes (B) It treats urinary tract infections (C) It filters wastes out of the blood (D) It removes stones from the kidneys,C,"Kidney failure happens when the kidneys cannot remove wastes from the blood. If the kidneys are unable to filter wastes from the blood, the wastes build up in the body. Kidney failure can be caused by an accident that injures the kidneys, the loss of a lot of blood, or by some drugs and poisons. Kidney failure may lead to permanent loss of kidney function. But if the kidneys are not seriously damaged, they may recover. Chronic kidney disease is the slow decrease in kidney function that may lead to permanent kidney failure. A person who has lost kidney function may need to get kidney dialysis. Kidney dialysis is the process of filtering the blood of wastes using a machine. A dialysis machine ( Figure 1.2) filters waste from the blood by pumping the blood through a fake kidney. The filtered blood is then returned to the patients body. "
One function of the kidneys is to help keep blood pressure within a normal range.,(A) true (B) false,A,"The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. For example, they produce a hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete a hormone that regulates blood pressure and keeps it in a normal range. "
"You need both kidneys to live a normal, healthy life.",(A) true (B) false,B,"You need only one kidney to live a normal, healthy life. A single kidney can do all the work of filtering the blood and maintaining homeostasis. However, at least one kidney must function properly to maintain life. Diseases that threaten the health and functioning of the kidneys include kidney stones, infections, and diabetes. You can learn more about kidney diseases in this video:  . MEDIA Click image to the left or use the URL below. URL:  Kidney stones are mineral crystals that form in urine inside a kidney, as shown in Figure 19.8. The stones may be extremely painful. If a kidney stone blocks a ureter, it must be removed so urine can leave the kidney and be excreted. Bacterial infections of urinary organs, especially the urinary bladder, are common. They are called urinary tract infections. Generally, they can be cured with antibiotic drugs. However, if they arent treated, they can lead to more serious infections and damage to the kidneys. Untreated diabetes may damage capillaries in the kidneys so the nephrons can no longer filter blood. This is called kidney failure. The only cure for kidney failure is to receive a healthy transplanted kidney from a donor. Until that happens, a patient with kidney failure can be kept alive by artificially filtering the blood through a machine. This is called hemodialysis. You can see how it works in Figure 19.9. "
Excess water is removed from your body when you,(A) urinate (B) exhale (C) sweat (D) all of the above,D,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
The urinary system includes all of the following organs except the,(A) liver (B) ureters (C) urethra (D) urinary bladder,A,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
How many nephrons does each kidney contain?,(A) fewer than 10 (B) around 100 (C) about 1 (D) 000 (E) d more than 1 (F) 000 (G) 000,D,"The kidneys are a pair of bean-shaped organs at each side of the body just above the waist. You can see a diagram of a kidney in Figure 19.7. The function of the kidneys is to filter blood and form urine. Tiny structures in the kidneys, called nephrons, perform this function. Each kidney contains more than a million nephrons. "
Clean blood leaves a kidney through a(n),(A) artery (B) capillary (C) urethra (D) vein,D,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
The liver removes excess water and salts from the blood.,(A) true (B) false,B,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
Each kidney contains more than a million nephrons.,(A) true (B) false,A,"The kidneys are a pair of bean-shaped organs at each side of the body just above the waist. You can see a diagram of a kidney in Figure 19.7. The function of the kidneys is to filter blood and form urine. Tiny structures in the kidneys, called nephrons, perform this function. Each kidney contains more than a million nephrons. "
Urine moves through the ureters by,(A) gravity (B) diffusion (C) peristalsis (D) none of the above,C,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
Some of the water filtered out of the blood by nephrons is reabsorbed.,(A) true (B) false,A,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
How do the kidneys help maintain homeostasis?,(A) They control the amount of water in the body (B) They secrete a hormone that regulates sweat production (C) They secrete a hormone that stimulates muscle contractions (D) all of the above,A,"The kidneys help the body maintain homeostasis in several ways. They filter all the blood in the body many times each day and produce urine. They control the amount of water and dissolved substances in the blood by excreting more or less of them in urine. The kidneys also secrete hormones that help maintain homeostasis. For example, they produce a hormone that stimulates bone marrow to produce red blood cells when more are needed. They also secrete a hormone that regulates blood pressure and keeps it in a normal range. "
How does untreated diabetes cause kidney failure?,(A) It leads to kidney stones that damage nephrons (B) It damages capillaries in the kidneys (C) It causes frequent urinary tract infections (D) It causes urine to back up in the kidneys,B,"Diabetes is a non-infectious disease in which the body is unable to control the amount of sugar in the blood. People with diabetes have high blood sugar, either because their bodies do not produce enough insulin, or because their cells do not respond to insulin. Insulin is a hormone that helps cells take up sugar from the blood. Without enough insulin, the blood contains too much sugar. This can damage blood vessels and other cells throughout the body. The kidneys work hard to filter out and remove some of the extra sugar. This leads to frequent urination and excessive thirst. There are two main types of diabetes, type 1 diabetes and type 2 diabetes. Type 1 diabetes makes up about 5-10% of all cases of diabetes in the United States. Type 2 diabetes accounts for most of the other cases. Both types of diabetes are more likely in people that have certain genes. Having a family member with diabetes increases the risk of developing the disease. Either type of diabetes can increase the chances of having other health problems. For example, people with diabetes are more likely to develop heart disease and kidney disease. Type 1 and type 2 diabetes are similar in these ways. However, the two types of diabetes have different causes. "
The bladder is the urinary system organ where urine forms.,(A) true (B) false,B,"1. As you can see above ( Figure 1.1), the kidneys are two bean-shaped organs. Kidneys filter and clean the blood and form urine. They are about the size of your fists and are found near the middle of the back, just below your ribcage. 2. Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder. 3. The urinary bladder is a hollow and muscular organ. It is shaped a little like a balloon. It is the organ that collects urine. 4. Urine leaves the body through the urethra. The kidneys filter the blood that passes through them, and the urinary bladder stores the urine until it is released from the body. "
The only cure for kidney failure is a kidney transplant.,(A) true (B) false,A,"You need only one kidney to live a normal, healthy life. A single kidney can do all the work of filtering the blood and maintaining homeostasis. However, at least one kidney must function properly to maintain life. Diseases that threaten the health and functioning of the kidneys include kidney stones, infections, and diabetes. You can learn more about kidney diseases in this video:  . MEDIA Click image to the left or use the URL below. URL:  Kidney stones are mineral crystals that form in urine inside a kidney, as shown in Figure 19.8. The stones may be extremely painful. If a kidney stone blocks a ureter, it must be removed so urine can leave the kidney and be excreted. Bacterial infections of urinary organs, especially the urinary bladder, are common. They are called urinary tract infections. Generally, they can be cured with antibiotic drugs. However, if they arent treated, they can lead to more serious infections and damage to the kidneys. Untreated diabetes may damage capillaries in the kidneys so the nephrons can no longer filter blood. This is called kidney failure. The only cure for kidney failure is to receive a healthy transplanted kidney from a donor. Until that happens, a patient with kidney failure can be kept alive by artificially filtering the blood through a machine. This is called hemodialysis. You can see how it works in Figure 19.9. "
__muscular tube that carries urine out of the body,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,D,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
__tiny structure in a kidney that filters blood and forms urine,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,C,"The kidneys are a pair of bean-shaped organs at each side of the body just above the waist. You can see a diagram of a kidney in Figure 19.7. The function of the kidneys is to filter blood and form urine. Tiny structures in the kidneys, called nephrons, perform this function. Each kidney contains more than a million nephrons. "
__sac-like organ that stores urine,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,G,"1. As you can see above ( Figure 1.1), the kidneys are two bean-shaped organs. Kidneys filter and clean the blood and form urine. They are about the size of your fists and are found near the middle of the back, just below your ribcage. 2. Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder. 3. The urinary bladder is a hollow and muscular organ. It is shaped a little like a balloon. It is the organ that collects urine. 4. Urine leaves the body through the urethra. The kidneys filter the blood that passes through them, and the urinary bladder stores the urine until it is released from the body. "
__mineral crystal that forms in urine inside a kidney,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,B,"In some cases, certain mineral wastes can form kidney stones ( Figure 1.1). Stones form in the kidneys and may be found anywhere in the urinary system. Often, stones form when the urine becomes concentrated, allowing minerals to crystallize and stick together. They can vary in size, from small stones that can flow through your urinary system, to larger stones that cannot. Some stones cause great pain, while others cause very little pain. Some stones may need to be removed by surgery or ultrasound treatments. What are the symptoms of kidney stones? You may have a kidney stone if you have pain while urinating, see blood in your urine, and/or feel a sharp pain in your back or lower abdomen (the area between your chest and hips). The pain may last for a long or short time. You may also have nausea and vomiting with the pain. If you have a small stone that passes on its own easily, you may not experience any symptoms. If you have some of these symptoms, you should see your doctor. A kidney stone. The stones can form anywhere in the urinary system. "
__artificial filtering of blood through a machine,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,F,"Platelets ( Figure 1.4) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. "
__muscular tube that carries urine from a kidney to the urinary bladder,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,A,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
__main organ of the urinary system,(A) aureter (B) bkidney stone (C) cnephron (D) durethra (E) ekidney (F) fhemodialysis (G) gurinary bladder,E,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
_________smallest particle of an element that still has the properties of that element,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,E,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
_________carbohydrate that makes up the cell walls of plants,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,D,"The cell wall is a rigid layer that surrounds the cell membrane of a plant cell. Its made mainly of the complex carbohydrate called cellulose. The cell wall supports and protects the cell. The cell wall isnt solid like a brick wall. It has tiny holes in it called pores. The pores let water, nutrients, and other substances move into and out of the cell. "
_________biochemical compound that consists of nucleotides,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,G,"Nucleic acids are biochemical compounds that include RNA (ribonucleic acid) and DNA (deoxyribonucleic acid). Nucleic acids consist of chains of small molecules called nucleotides. Nucleotides are the monomers of nucleic 40 acids. A nucleotide is shown in Figure 2.11. Each nucleotide consists of: 1. a phosphate group, which contains phosphorus and oxygen. 2. a sugar, which is deoxyribose in DNA and ribose in RNA. 3. one of four nitrogen-containing bases. (A base is a compound that is not neither acidic nor neutral.) In DNA, the bases are adenine, thymine, guanine, and cytosine. RNA has the base uracil instead of thymine, but the other three bases are the same. RNA consists of just one chain of nucleotides. DNA consists of two chains. Nitrogen bases on the two chains of DNA form bonds with each other. The bonded bases are called base pairs. Bonds form only between adenine and thymine, and between guanine and cytosine. They hold together the two chains of DNA and give it its characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in Figure 2.12. Sugars and phosphate groups form the backbone of each chain of DNA. Determining the structure of DNA was a huge scientific breakthrough. You can read the interesting story of its discovery and why it was so important at this link: DNA stores genetic information in the cells of all living things. It contains the genetic code. This is the code that instructs cells how to make proteins. The instructions are encoded in the sequence of nitrogen bases in DNAs nucleotide chains. RNA copies and interprets the genetic code in DNA. RNA is also involved in the synthesis of proteins based on the code. You can watch these events unfolding at this link: MEDIA Click image to the left or use the URL below. URL: "
_________smallest particle of a compound that still has the properties of that compound,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,C,"The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure 2.6. An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. The smallest particle of a compound that still has the properties of that compound is a molecule. A molecule consists of two or more atoms. For example, a molecule of water consists of two atoms of hydrogen and one atom of oxygen. Thats why the chemical formula for water is H2 O. You can see a simple model of a water molecule in Figure 2.7. "
_________class of biochemical compound that consists of amino acids,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,B,"Hemoglobin is a compound in the class of compounds called proteins. Proteins are one of four classes of biochemi- cal compounds, which are compounds in living things. (The other three classes are carbohydrates, lipids, and nucleic acids.) Proteins contain carbon, hydrogen, oxygen, nitrogen, and sulfur. Protein molecules consist of one or more chains of small molecules called amino acids. "
_________class of biochemical compound that consists of fatty acids,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,F,"Lipids are one of four classes of biochemical compounds, which are compounds that make up living things and carry out life processes. (The other three classes of biochemical compounds are carbohydrates, proteins, and nucleic acids.) Living things use lipids to store energy. Lipids are also the major components of cell membranes in living things. Types of lipids include fats and oils. Fats are solid lipids that animals use to store energy. Oils are liquid lipids that plants use to store energy. Q: Can you name some lipids that are fats? What are some lipids that are oils? A: Lipids that are fats include butter and the fats in meats. Lipids that are oils include olive oil and vegetable oil. Examples of both types of lipids are pictured in the Figure 1.1. "
_________protein that speeds up biochemical reactions,(A) aenzyme (B) bprotein (C) cmolecule (D) dcellulose (E) eatom (F) flipid (G) gnucleic acid,A,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
_________Atoms can be observed only with an electron microscope.,(A) true (B) false,A,"The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure 2.6. An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. The smallest particle of a compound that still has the properties of that compound is a molecule. A molecule consists of two or more atoms. For example, a molecule of water consists of two atoms of hydrogen and one atom of oxygen. Thats why the chemical formula for water is H2 O. You can see a simple model of a water molecule in Figure 2.7. "
_________Glycogen is a complex carbohydrate found in animals.,(A) true (B) false,A,"Carbohydrates are biochemical compounds that include sugar, starch, glycogen, and cellulose. Sugars are simple carbohydrates with relatively small molecules. Glucose is the smallest of all the sugar molecules with its chemical formula of C6 H12 O6 . This means that a molecule of glucose contains 6 atoms of carbon, 12 atoms of hydrogen, and 6 atoms of oxygen. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose can obtain it by consuming plants or organisms that consume plants. Starches are complex carbohydrates. They are polymers of glucose. Starches contain hundreds of glucose monomers. Plants make starches to store extra glucose. Consumers can get starches by eating plants. Common sources of starches in the human diet are pictured in the Figure 2.8. Our digestive system breaks down starches to sugar, which our cells use for energy. Like other animals, we store any extra glucose as the complex carbohydrate called glycogen. Glycogen is also a polymer of glucose. Cellulose is another complex carbohydrate found in plants that is a polymer of glucose. Cellulose molecules bundle together to form long, tough fibers. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to stems and tree trunks. "
_________Glucose is a polymer of starch.,(A) true (B) false,B,"Starches are complex carbohydrates. They are polymers of glucose. A polymer is a large molecule that consists of many smaller, repeating molecules, called monomers. The monomers are joined together by covalent bonds. Starches contain hundreds of glucose monomers. Plants make starches to store extra glucose. Consumers get starches by eating plants. Common sources of starches in the human diet are pictured in the Figure 1.2. Our digestive system breaks down starches to sugar, which our cells use for energy. "
_________Saturated fatty acids are found in oils,(A) true (B) false,B,"Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, the carbons are saturated with hydrogen atoms. Saturated fatty acids are found in fats. Fats are solid lipids that animals use to store energy. In unsaturated fatty acids, there is at least one double bond between carbon atoms. As a result, some carbons are not bonded to as many hydrogen atoms as possible. Unsaturated fatty acids are found in oils. Oils are liquid lipids that plants use to store energy. "
_________The genetic code tells cells how to make proteins.,(A) true (B) false,A,"How is the information for making proteins encoded in DNA? The answer is the genetic code. The genetic code is based on the sequence of nitrogen bases in DNA. The four bases make up the letters of the code. Groups of three bases each make up code words. These three-letter code words are called codons. Each codon stands for one amino acid or else for a start or stop signal. There are 20 amino acids that make up proteins. With three bases per codon, there are 64 possible codons. This is more than enough to code for the 20 amino acids plus start and stop signals. You can see how to translate the genetic code in Figure 5.17. Start at the center of the chart for the first base of each three-base codon. Then work your way out from the center for the second and third bases. Find the codon AUG in Figure 5.17. It codes for the amino acid methionine. It also codes for the start signal. After an AUG start codon, the next three letters are read as the second codon. The next three letters after that are read as the third codon, and so on. You can see how this works in Figure 5.18. The figure shows the bases in a molecule "
_________The substances that start a chemical reaction are called products.,(A) true (B) false,B,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
_________Cellular respiration involves catabolic reactions.,(A) true (B) false,A,"The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. The rest of the energy is used to form many small molecules of a compound called adenosine triphosphate, or ATP. ATP molecules contain just the right amount of stored chemical energy to power biochemical reactions inside cells. Click image to the left or use the URL below. URL: "
Major elements in the human body include,(A) hydrogen (B) carbon dioxide (C) water (D) all of the above,A,"An element is pure substance that cannot be broken down into other substances. Each element has a particular set of properties that, taken together, distinguish it from all other elements. Table 2.1 lists the major elements in the human body. As you can see, you consist mainly of the elements oxygen, carbon, and hydrogen. Element Oxygen Carbon Hydrogen Nitrogen Calcium Phosphorus Potassium Sulfur Percent of Body Mass 65 18 10 3 1.5 1.0 0.35 0.25 In your body, most elements are combined with other elements to form chemical compounds. A compound is a unique type of matter in which two or more elements are combined chemically in a certain ratio. For example, much of the oxygen and hydrogen in your body are combined in the chemical compound water, or H2O. "
Which of the following is one of the four main classes of biochemical compounds?,(A) carbohydrates (B) sugars (C) fats (D) DNA,A,"Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element. "
Uses of lipids include,(A) storing energy (B) making proteins (C) making up cell walls (D) regulating life processes,A,"Lipids are biochemical compounds that living things use to store energy and make cell membranes. Types of lipids include fats, oils, and phospholipids. Fats are solid lipids that animals use to store energy. Examples of fats include butter and the fat in meat. Oils are liquid lipids that plants use to store energy. Examples of oils include olive oil and corn oil. Phospholipids contain the element phosphorus. They make up the cell membranes of living things. Lipids are made of long chains consisting almost solely of carbon and hydrogen. These long chains are called fatty acids. Fatty acids may be saturated or unsaturated. The Figure 2.10 shows an example of each type of fatty acid. "
Functions of proteins include,(A) making up muscles (B) fighting infections (C) transporting materials (D) all of the above,D,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
How does RNA differ from DNA?,(A) RNA consists of one chain of nucleotides rather than two chains (B) RNA has the nitrogen base thymine instead of uracil (C) RNA is a fatty acid rather than a nucleic acid (D) all of the above,A,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
Anabolic reactions are biochemical reactions in which,(A) chemical bonds are broken (B) chemical bonds are formed (C) energy is released (D) two of the above,B,"The sum of all of an organisms biochemical reactions is called metabolism. Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. You can watch an animation showing how the two categories of reactions are related at this link: Anabolic reactions involve forming bonds. Smaller molecules combine to form larger ones. These reactions require energy. For example, it takes energy to build starches from sugars. Catabolic reactions involve breaking bonds. Larger molecules break down to form smaller ones. These reactions release energy. For example, energy is released when starches break down to sugars. "
Which statement about enzymes is true?,(A) Enzymes are products in biochemical reactions (B) Enzymes speed up biochemical reactions (C) Enzymes are used up in biochemical reactions (D) Enzymes are reactants in biochemical reactions,B,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
A bundle of nerve cells make up a(n),(A) neuron (B) nerve (C) axon (D) lobe,B,"The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons are called nerve impulses. A nerve impulse can travel very quickly because it is an electrical signal. Think about flipping on a light switch when you enter a room. When you flip the switch, electricity flows to the light through wires inside the walls. The electricity may have to travel many meters to reach the light. Nonetheless, the light still comes on as soon as you flip the switch. Nerve impulses travel just as quickly through the network of nerves inside the body. "
Functions of the human nervous system include,(A) sensing the internal and external environments (B) helping maintain homeostasis of the body (C) preparing the body to fight or flee in emergencies (D) all of the above,D,"Controlling muscles and maintaining balance are just two of the functions of the human nervous system. What else does the nervous system do? It senses the surrounding environment with sense organs that include the eyes and ears. It senses the bodys own internal environment, including its temperature. It controls internal body systems to make sure the body maintains homeostasis. It prepares the body to fight or flee in the case of an emergency. It allows thinking, learning, memory, and language. Remember Hakeem the skater from the first page of the chapter? When Hakeem started to fall off the railing, his nervous system sensed that he was losing his balance. It responded by sending messages to his muscles. Some muscles contracted while other relaxed. As a result, Hakeem gained his balance again. How did his nervous system accomplish all of this in just a split second? You need to know how the nervous system transmits messages to answer that question. "
How do nerve impulses travel across a synapse?,(A) They swim across through synaptic fluid (B) They are carried across by special chemicals (C) They jump across like an electric spark (D) They move across through interneurons,B,"The nerve endings of an axon dont actually touch the dendrites of other neurons. The messages must cross a tiny gap between the two neurons, called the synapse. Chemicals called neurotransmitters carry the message across this gap. When a nerve impulse arrives at the end of an axon, neurotransmitters are released. They travel across the synaptic gap to a dendrite of another neuron. The neurotransmitters bind to the membrane of the dendrite, triggering a nerve impulse in the next neuron. You can see how this works in Figure 20.3 and in this animation:  The transmission of nerve impulses between neurons is like the passing of a baton between runners in a relay race. After the first runner races, she passes the baton to the second runner. Then the second runner takes over. Instead of a baton, a neuron passes neurotransmitters to the next neuron. "
The type of neuron that carries messages from the brain to internal organs and glands is a(n),(A) motor neuron (B) sensory neuron (C) organ neuron (D) endocrine neuron,A,"There are three basic types of neurons: sensory neurons, motor neurons, and interneurons. All three types must work together to receive and respond to information. 1. Sensory neurons transmit nerve impulses from sense organs and internal organs to the brain via the spinal cord. In other words, they carry information about the inside and outside environment to the brain. 2. Motor neurons transmit nerve impulses from the brain via the spinal cord to internal organs, glands, and muscles. In other words, they carry information from the brain to the body, telling the body how to respond. 3. Interneurons carry nerve impulses back and forth between sensory and motor neurons. "
The brain stem,(A) is the smallest of the three main part of the brain (B) carries nerve impulses between the brain and spinal cord (C) controls involuntary body functions such as digestion (D) all of the above,D,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
Which statement about the brain is false?,(A) It is the most complex organ in the body (B) It is the largest organ in the body (C) It consists of billions of neurons (D) It serves as the control center of the body,B,"What weighs about three pounds and contains up to 100 billion cells? The answer is the human brain. The brain is the control center of the nervous system. Its like the pilot of a plane. It tells other parts of the nervous system what to do. The brain is also the most complex organ in the body. Each of its 100 billion neurons has synapses connecting it with thousands of other neurons. All those neurons use a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body. The developing brain of a baby uses an even greater amount of the bodys total energy. The brain is the organ that lets us understand what we see, hear, or sense in other ways. It also allows us to use language, learn, think, and remember. The brain controls the organs in our body and our movements as well. The brain consists of three main parts, the cerebrum, the cerebellum, and the brain stem ( Figure 1.2). 1. The cerebrum is the largest part of the brain. It sits on top of the brain stem. The cerebrum controls functions that we are aware of, such as problem-solving and speech. It also controls voluntary movements, like waving to a friend. Whether you are doing your homework or jumping hurdles, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It lies under the cerebrum and behind the brain stem. The cerebellum controls body position, coordination, and balance. Whether you are riding a bicycle or writing with a pen, you are using your cerebellum. 3. The brain stem is the smallest of the three main parts of the brain. It lies directly under the cerebrum. The brain stem controls basic body functions, such as breathing, heartbeat, and digestion. The brain stem also carries information back and forth between the cerebrum and spinal cord. The cerebrum is divided into a right and left half ( Figure 1.2). Each half of the cerebrum is called a hemisphere. The two hemispheres are connected by a thick bundle of axons called the corpus callosum. It lies deep inside the brain and carries messages back and forth between the two hemispheres. Did you know that the right hemisphere controls the left side of the body, and the left hemisphere controls the right side of the body? By connecting the two hemispheres, the corpus callosum allows this to happen. Each hemisphere of the cerebrum is divided into four parts, called lobes. The four lobes are the: 1. 2. 3. 4. Frontal. Parietal. Temporal. Occipital. Each lobe has different jobs. Some of the functions are listed below ( Table 1.1). Side view of the brain (right). Can you find the locations of the three major parts of the brain? Top view of the brain (left). Lobe Frontal Parietal Temporal Occipital Main Function(s) Speech, thinking, touch Speech, taste, reading Hearing, smell Sight "
Which part of the brain controls involuntary functions such as heartbeat?,(A) cerebrum (B) cerebellum (C) brain stem (D) temporal lobe,C,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
The part of the cerebrum that controls hearing is the,(A) frontal lobe (B) parietal lobe (C) temporal lobe (D) occipital lobe,C,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
Which part of the peripheral nervous system controls only involuntary responses of the body?,(A) sensory division (B) motor division (C) somatic nervous system (D) autonomic nervous system,D,"The motor division of the peripheral nervous system carries messages from the central nervous system to muscles, internal organs, and glands throughout the body. The brain sends commands to these tissues, telling them how to respond. As you can see in Figure 20.7, the motor division is divided into additional parts. The autonomic part of the motor division controls involuntary responses. It sends messages to organs and glands. These messages control the body both during emergencies (sympathetic division) and during none- mergencies (parasympathetic division). The somatic part of the motor division controls voluntary responses. It sends messages to the skeletal muscles for movements that are under conscious control. "
Which part of the peripheral nervous system controls muscles that are under voluntary control?,(A) sympathetic division (B) parasympathetic division (C) somatic nervous system (D) autonomic nervous system,C,"The motor division of the peripheral nervous system carries messages from the central nervous system to muscles, internal organs, and glands throughout the body. The brain sends commands to these tissues, telling them how to respond. As you can see in Figure 20.7, the motor division is divided into additional parts. The autonomic part of the motor division controls involuntary responses. It sends messages to organs and glands. These messages control the body both during emergencies (sympathetic division) and during none- mergencies (parasympathetic division). The somatic part of the motor division controls voluntary responses. It sends messages to the skeletal muscles for movements that are under conscious control. "
Central nervous system infections include,(A) encephalitis (B) epilepsy (C) meningitis (D) two of the above,D,"Bacteria and viruses can infect the brain or spinal cord. An infection of the brain is called encephalitis. An infection of the membranes that cover the brain and spinal cord is called meningitis. A vaccine is available to prevent meningitis caused by viruses (see Figure 20.8). Encephalitis and meningitis arent very common, but they can be extremely serious. They may cause swelling of the brain, which can be fatal. Thats why its important to know the symptoms of these diseases. Both encephalitis and meningitis typically cause a severe headache and a fever. Meningitis also causes a stiff neck. Both require emergency medical treatment. "
Use of a drug without the advice of medical professionals and for reasons not originally intended is referred to as,(A) drug addiction (B) drug overdose (C) drug abuse (D) none of the above,C,"Psychoactive drugs may bring about changes in mood that users find desirable. These drugs may be abused. Drug abuse is use of a drug without the advice of a medical professional and for reasons not originally intended. Continued use of a psychoactive drug may lead to drug addiction. This occurs when a drug user is unable to stop using the drug. Over time, a drug user may need more of the drug to get the desired effect. This can lead to drug overdose and death. "
A stroke occurs when a blood clot blocks blood flow to part of the brain.,(A) true (B) false,A,"A stroke occurs when a blood clot blocks blood flow to part of the brain. Brain cells die quickly when their oxygen supply is cut off. Therefore, a stroke may cause permanent loss of normal mental functions. Many stroke patients suffer some degree of paralysis, or loss of the ability to feel or move certain parts of the body. If medical treatment is given very soon after a stroke occurs, some of the damage may be reversed. Strokes occur mainly in older adults. "
Psychoactive drugs include antidepressants and caffeine.,(A) true (B) false,A,"Many drugs affect the brain and influence how a person feels, thinks, or acts. Such drugs are called psychoactive drugs. They include legal drugs such as caffeine and alcohol, as well as illegal drugs such as cocaine and heroin. They also include certain medicines, such as antidepressant drugs and medical marijuana. Some psychoactive drugs, such as caffeine, stimulate the central nervous system. They may make the user feel more alert. Some psychoactive drugs, such as alcohol, depress the central nervous system. They may make the user feel more relaxed. Still other psychoactive drugs, such as marijuana, are hallucinogenic drugs. They may make the user have altered sensations, perceptions, or thoughts. "
The cerebellum is divided down the middle to form right and left hemispheres.,(A) true (B) false,B,"The cerebrum is divided down the middle from the front to the back of the head. The two halves of the cerebrum are called the right and left hemispheres. The two hemispheres are very similar but not identical. They are connected to each other by a thick bundle of axons deep within the brain. These axons allow the two hemispheres to communicate with each other. Did you know that the right hemisphere of the cerebrum controls the left side of the body, and vice versa? This can happen because of the connections between the two hemispheres. Each hemisphere is further divided into four parts, called lobes, as you can see in Figure 20.6. Each lobe has different functions. One function of each lobe is listed in the figure. "
The spinal cord is part of the peripheral nervous system.,(A) true (B) false,B,"The nervous system has two main parts, called the central nervous system and the peripheral nervous system. The peripheral nervous system is described later in this lesson. The central nervous system is shown in Figure 20.4. It includes the brain and spinal cord. "
The sensory division of the peripheral nervous system carries messages away from the brain.,(A) true (B) false,B,"The sensory division of the peripheral nervous system carries messages from sense organs and internal organs to the central nervous system. For example, it carries messages about images from the eyes to the brain. Once the messages reach the brain, the brain interprets the information. "
A single neuron may have thousands of dendrites.,(A) true (B) false,A,"A neuron has a special shape that lets it pass signals from one cell to another. A neuron has three main parts ( Figure 1. The cell body. 2. Many dendrites. 3. One axon. The cell body contains the nucleus and other organelles. Dendrites and axons connect to the cell body, similar to rays coming off of the sun. Dendrites receive nerve impulses from other cells. Axons pass the nerve impulses on to other cells. A single neuron may have thousands of dendrites, so it can communicate with thousands of other cells but only one axon. The axon is covered with a myelin sheath, a fatty layer that insulates the axon and allows the electrical signal to travel much more quickly. The node of Ranvier is any gap within the myelin sheath exposing the axon, and it allows even faster transmission of a signal. "
The cerebellum controls conscious functions such as thinking and speaking.,(A) true (B) false,B,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
The two hemispheres of the cerebrum are identical to each other.,(A) true (B) false,B,"The cerebrum is divided down the middle from the front to the back of the head. The two halves of the cerebrum are called the right and left hemispheres. The two hemispheres are very similar but not identical. They are connected to each other by a thick bundle of axons deep within the brain. These axons allow the two hemispheres to communicate with each other. Did you know that the right hemisphere of the cerebrum controls the left side of the body, and vice versa? This can happen because of the connections between the two hemispheres. Each hemisphere is further divided into four parts, called lobes, as you can see in Figure 20.6. Each lobe has different functions. One function of each lobe is listed in the figure. "
The peripheral nervous system includes all of the nervous tissue in the body except for the brain.,(A) true (B) false,B,"All the other nervous tissues in the body are part of the peripheral nervous system. If you look again at Figure 20.1, you can see the major nerves of the peripheral nervous system. They include nerves that run through virtually every part of the body, both inside and out, except for the brain and spinal cord. The peripheral nervous system has two main divisions: the sensory division and the motor division. The divisions carry messages in opposite directions. Figure 20.7 shows these divisions of the peripheral nervous system. "
The sympathetic division of the autonomic nervous system prepares the body for emergencies.,(A) true (B) false,A,"The motor division of the peripheral system carries messages from the central nervous system to internal organs and muscles. The motor division is also divided into two parts ( Figure 1.2), the somatic nervous system and the autonomic nervous system. The somatic nervous system carries messages that control body movements. It is responsible for activities that are under your control, such as waving your hand or kicking a ball. The girl pictured below ( Figure 1.4) is using her somatic nervous system to control the muscles needed to play the violin. Her brain sends messages to motor neurons that move her hands so she can play. Without the messages from her brain, she would not be able to move her hands and play the violin. The autonomic nervous system carries nerve impulses to internal organs. It controls activities that are not under your control, such as sweating and digesting food. The autonomic nervous system has two parts: 1. The sympathetic division controls internal organs and glands during emergencies. It prepares the body for fight or flight ( Figure 1.5). For example, it increases the heart rate and the flow of blood to the legs, so you can run away from danger. 2. The parasympathetic division controls internal organs and glands during the rest of the time. It controls processes like digestion, heartbeat, and breathing when there is not an emergency. Have you ever become frightened and felt your heart start pounding? How does this happen? The answer is your autonomic nervous system. The sympathetic division prepared you to deal with a possible emergency by increasing "
Seizures in epilepsy are caused by abnormal electrical activity in the brain.,(A) true (B) false,A,"Epilepsy is a disease in which seizures occur. A seizure is a period of lost consciousness that may include violent muscle contractions. It is caused by abnormal electrical activity in the brain. Epilepsy may result from an infection, injury, or tumor. In many cases, however, the cause cant be identified. There is no known cure for epilepsy, but the seizures often can be prevented with medicine. Sometimes children with epilepsy outgrow it by adulthood. "
All psychoactive drugs are illegal drugs.,(A) true (B) false,B,"Many drugs affect the brain and influence how a person feels, thinks, or acts. Such drugs are called psychoactive drugs. They include legal drugs such as caffeine and alcohol, as well as illegal drugs such as cocaine and heroin. They also include certain medicines, such as antidepressant drugs and medical marijuana. Some psychoactive drugs, such as caffeine, stimulate the central nervous system. They may make the user feel more alert. Some psychoactive drugs, such as alcohol, depress the central nervous system. They may make the user feel more relaxed. Still other psychoactive drugs, such as marijuana, are hallucinogenic drugs. They may make the user have altered sensations, perceptions, or thoughts. "
__type of nerve cell that carries nerve impulses back and forth between sensory and motor neurons,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,G,"Neurons are usually classified based on the role they play in the body. Two main types of neurons are sensory neurons and motor neurons. Sensory neurons carry nerve impulses from sense organs and internal organs to the central nervous system. Motor neurons carry nerve impulses from the central nervous system to organs, glands, and musclesthe opposite direction. Both types of neurons work together. Sensory neurons carry information about the environment found inside or outside of the body to the central nervous system. The central nervous system uses the information to send messages through motor neurons to tell the body how to respond to the information. "
__largest part of the brain,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,F,"What weighs about three pounds and contains up to 100 billion cells? The answer is the human brain. The brain is the control center of the nervous system. Its like the pilot of a plane. It tells other parts of the nervous system what to do. The brain is also the most complex organ in the body. Each of its 100 billion neurons has synapses connecting it with thousands of other neurons. All those neurons use a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body. The developing brain of a baby uses an even greater amount of the bodys total energy. The brain is the organ that lets us understand what we see, hear, or sense in other ways. It also allows us to use language, learn, think, and remember. The brain controls the organs in our body and our movements as well. The brain consists of three main parts, the cerebrum, the cerebellum, and the brain stem ( Figure 1.2). 1. The cerebrum is the largest part of the brain. It sits on top of the brain stem. The cerebrum controls functions that we are aware of, such as problem-solving and speech. It also controls voluntary movements, like waving to a friend. Whether you are doing your homework or jumping hurdles, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It lies under the cerebrum and behind the brain stem. The cerebellum controls body position, coordination, and balance. Whether you are riding a bicycle or writing with a pen, you are using your cerebellum. 3. The brain stem is the smallest of the three main parts of the brain. It lies directly under the cerebrum. The brain stem controls basic body functions, such as breathing, heartbeat, and digestion. The brain stem also carries information back and forth between the cerebrum and spinal cord. The cerebrum is divided into a right and left half ( Figure 1.2). Each half of the cerebrum is called a hemisphere. The two hemispheres are connected by a thick bundle of axons called the corpus callosum. It lies deep inside the brain and carries messages back and forth between the two hemispheres. Did you know that the right hemisphere controls the left side of the body, and the left hemisphere controls the right side of the body? By connecting the two hemispheres, the corpus callosum allows this to happen. Each hemisphere of the cerebrum is divided into four parts, called lobes. The four lobes are the: 1. 2. 3. 4. Frontal. Parietal. Temporal. Occipital. Each lobe has different jobs. Some of the functions are listed below ( Table 1.1). Side view of the brain (right). Can you find the locations of the three major parts of the brain? Top view of the brain (left). Lobe Frontal Parietal Temporal Occipital Main Function(s) Speech, thinking, touch Speech, taste, reading Hearing, smell Sight "
__part of a neuron that contains the nucleus and other organelles,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,C,"A neuron has a special shape that lets it pass signals from one cell to another. A neuron has three main parts ( Figure 1. The cell body. 2. Many dendrites. 3. One axon. The cell body contains the nucleus and other organelles. Dendrites and axons connect to the cell body, similar to rays coming off of the sun. Dendrites receive nerve impulses from other cells. Axons pass the nerve impulses on to other cells. A single neuron may have thousands of dendrites, so it can communicate with thousands of other cells but only one axon. The axon is covered with a myelin sheath, a fatty layer that insulates the axon and allows the electrical signal to travel much more quickly. The node of Ranvier is any gap within the myelin sheath exposing the axon, and it allows even faster transmission of a signal. "
__part of the brain that controls coordination and balance,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,B,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
__part of a neuron that receives nerve impulses from other cells,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,D,"The structure of a neuron suits it for its function of transmitting nerve impulses. You can see what a neuron looks like in Figure 20.2. It has a special shape that lets it pass electrical signals to and from other cells. A neuron has three main parts: cell body, dendrites, and axon. 1. The cell body contains the nucleus and other organelles. 2. Dendrites receive nerve impulses from other cells. A single neuron may have thousands of dendrites. 3. The axon passes on the nerve impulses to other cells. It branches at the end into multiple nerve endings so it can transmit impulses to many other cells. "
__part of a neuron that passes on nerve impulses to other cells,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,A,"The structure of a neuron suits it for its function of transmitting nerve impulses. You can see what a neuron looks like in Figure 20.2. It has a special shape that lets it pass electrical signals to and from other cells. A neuron has three main parts: cell body, dendrites, and axon. 1. The cell body contains the nucleus and other organelles. 2. Dendrites receive nerve impulses from other cells. A single neuron may have thousands of dendrites. 3. The axon passes on the nerve impulses to other cells. It branches at the end into multiple nerve endings so it can transmit impulses to many other cells. "
__electrical message carried by neurons,(A) aaxon (B) bcerebellum (C) ccell body (D) ddendrite (E) enerve impulse (F) fcerebrum (G) ginterneuron,E,"The nervous system is made up of nerves. A nerve is a bundle of nerve cells. A nerve cell that carries messages is called a neuron. The messages carried by neurons are called nerve impulses. A nerve impulse can travel very quickly because it is an electrical signal. Think about flipping on a light switch when you enter a room. When you flip the switch, electricity flows to the light through wires inside the walls. The electricity may have to travel many meters to reach the light. Nonetheless, the light still comes on as soon as you flip the switch. Nerve impulses travel just as quickly through the network of nerves inside the body. "
"In the eye, light is focused by the",(A) retina (B) cornea (C) lens (D) two of the above,D,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
We see most objects because they reflect light from another source.,(A) true (B) false,A,Almost all surfaces reflect some of the light that strikes them. The still water of the lake in Figure 22.9 reflects almost all of the light that strikes it. The reflected light forms an image of nearby objects. An image is a copy of an object that is formed by reflected or refracted light. 
The colored part of the eye is called the iris.,(A) true (B) false,A,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
Which statement about hyperopia is true?,(A) It can be corrected with convex lenses (B) It happens because the eyeball is too long (C) It occurs when images focus in front of the retina (D) two of the above,A,"Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure 1.2). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. Q: Joey has hyperopia. When is he more likely to need his glasses: when he reads a book or when he watches TV? A: With hyperopia, Joey is farsighted. He can probably see the TV more clearly than the words in a book because the TV is farther away. Therefore, he is more likely to need his glasses when he reads than when he watches TV. "
Nerve impulses travel from the ears to the brain through the,(A) optic nerve (B) spinal cord (C) auditory nerve (D) Eustachian tube,C,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
Hyperopia can be corrected with concave lenses.,(A) true (B) false,B,"Farsightedness is also known as hyperopia. It affects about one fourth of people. People with hyperopia can see distant objects clearly, but nearby objects appear blurry. In hyperopia, the eye is too short. This results in images being focused in back of the retina ( Figure 1.2). Hyperopia is corrected with a convex lens, which curves outward like the outside of a bowl. The lens changes the focus so that images fall on the retina as they should. Common signs of farsightedness include difficulty in concentrating and maintaining a clear focus on close objects, eye strain, fatigue and headaches after close work, and aching or burning eyes, especially after intense concentration on close work. In addition to lenses, many cases of myopia and hyperopia can be corrected with surgery. For example, a procedure called LASIK (Laser-Assisted in situ Keratomileusis) uses a laser to permanently change the shape of the cornea so light is correctly focused on the retina. "
The only function of the ears is to sense sound.,(A) true (B) false,B,"The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. "
How many different tastes can taste buds detect?,(A) 5 (B) 10 (C) 15 (D) 1 (E) 000,A,"Your sense of taste is controlled by sensory neurons, or nerve cells, on your tongue that sense the chemicals in food. The neurons are grouped in bundles within taste buds. Each taste bud actually has a pore that opens out to the surface of the tongue enabling molecules and ions taken into the mouth to reach the receptor cells inside. There are five different types of taste neurons on the tongue. Each type detects a different taste. The tastes are: 1. Sweet, which is produced by the presence of sugars, such as the common table sugar sucrose, and a few other substances. 2. Salty, which is produced primarily by the presence of sodium ions. Common salt is sodium chloride, NaCl. The use of salt can donate the sodium ion producing this taste. 3. Sour, which is the taste that detects acidity. The most common food group that contains naturally sour foods is fruit, such as lemon, grape, orange, and sometimes melon. Children show a greater enjoyment of sour flavors than adults, and sour candy such as Lemon Drops, Shock Tarts and sour versions of Skittles and Starburst, is popular. Many of these candies contain citric acid. 4. Bitter is an unpleasant, sharp, or disagreeable taste. Common bitter foods and beverages include coffee, unsweetened cocoa, beer (due to hops), olives, and citrus peel. 5. Umami, which is a meaty or savory taste. This taste can be found in fish, shellfish, cured meats, mushrooms, cheese, tomatoes, grains, and beans. A single taste bud contains 50100 taste cells representing all 5 taste sensations. A stimulated taste receptor cell triggers action potentials in a nearby sensory neuron, which send messages to the brain about the taste. The brain then decides what tastes you are sensing. "
Taste neurons on the tongue can detect thousands of different tastes.,(A) true (B) false,B,"The sense of taste is controlled by sensory neurons on the tongue. They are grouped in bundles called taste buds. You can see taste buds on the tongue in Figure 20.16. Taste neurons sense chemicals in food. They can detect five different tastes: sweet, salty, sour, bitter, and umami, which is a meaty taste. When taste neurons sense chemicals, they send messages to the brain about them. The brain then decides what you are tasting. The sense of smell also involves sensory neurons that sense chemicals. These neurons are found in the nose, and they sense chemicals in the air. Unlike taste neurons, smell neurons can detect thousands of different odors. Your sense of smell plays a big role in your sense of taste. You can use your sense of taste alone to learn that a food is sweet. However, you have to use your sense of smell as well to learn that the food tastes like apple pie. "
What happens when sound waves strike the eardrum?,(A) It vibrates (B) It sounds like a drum (C) It sends nerve impulses to the brain (D) none of the above,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
Sensory neurons in the nose sense chemicals in the air.,(A) true (B) false,A,"Your sense of smell also involves sensory neurons that sense chemicals. The neurons are found in the nose, and they detect chemicals in the air. Unlike taste neurons, which can detect only five different tastes, the sensory neurons in the nose can detect thousands of different odors. Have you ever noticed that you lose your sense of taste when your nose is stuffed up? Thats because your sense of smell greatly affects your ability to taste food. As you eat, molecules of food chemicals enter your nose (actually your nasal cavity). You experience the taste and smell at the same time. Being able to smell as well as taste food greatly increases the number of different flavors you are able to sense. For example, you can use your sense of taste alone to learn that a food is sweet, but you have to also use your sense of smell to learn that the food tastes like strawberry cheesecake. Specific scents are often associated with our memories of places and events. Thats because scents are more novel or specific than shapes or other things you might see. So an odor similar to that of your grandmothers kitchen or pantry might be more quickly associated with your memories of that place than a similar sight, which might be more generalized. "
The sense of smell plays an important role in the sense of taste.,(A) true (B) false,A,"The senses of taste and smell are more complicated than many people might think and have a surprisingly large impact on behavior, perception and overall health. Imagine your sense of smell disappearing as you age. Though this doesnt usually happen, it could provide clues about diseases of the nervous system. What about differences in taste? Do all foods taste the same to all people? Are there some foods you would never eat because you dont like the taste? Does this food taste good to other people? Genetic differences in taste could help predict what we eat, how well our metabolism works, and even whether or not were overweight. These two senses actually work together to provide some of the basic sensations of everyday life. "
__structure in the inner ear that responds to vibrations by sending nerve impulses to the auditory nerve,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,F,"The stirrup passes the amplified sound waves to the inner ear through the oval window (see Figure 20.7). When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has tiny hair-like projections, as you can see in Figure and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
__opening in the center of the eye that lets light pass through,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,C,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
__vision problem in which distant objects can be seen clearly but nearby objects appear blurry,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,B,"Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure 1.2). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. Q: Joey has hyperopia. When is he more likely to need his glasses: when he reads a book or when he watches TV? A: With hyperopia, Joey is farsighted. He can probably see the TV more clearly than the words in a book because the TV is farther away. Therefore, he is more likely to need his glasses when he reads than when he watches TV. "
__layer of cells at the back of the eye where images normally form,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,A,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
"If you lost vision in one eye, you could still see in three dimensions.",(A) true (B) false,B,"Did you ever use 3-D glasses to watch a movie, like the boy pictured below ( Figure 1.2)? If you did, then you know that the glasses make people and objects in the movie appear to jump out of the screen. They make images on the flat movie screen seem more realistic because they give them depth. Thats the difference between seeing things in two dimensions and three dimensions. We are able to see in three dimensions because we have two eyes facing the same direction but a few inches apart. As a result, we see objects and people with both eyes at the same time but from slightly different angles. Hold up a finger a few inches away from your face, and look at it, first with one eye and then with the other. Youll notice that your finger appears to move. Now hold up your finger at arms length, and look at it with one eye and then the other. Your finger seems to move less than it did when it was closer. Although you arent aware of it, your brain constantly uses such differences to determine the distance of objects. "
"When light reaches the eye, it passes first through the iris.",(A) true (B) false,B,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
__vision problem in which nearby objects can be seen clearly but distant objects appear blurry,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,G,"Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure 1.1 shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it. Q: Sometimes squinting the eyes can help someone see more clearly. Why do you think this works? A: Squinting may improve focus by slightly changing the shape of the eyes. When you squint, you tighten muscles around the eyes, putting pressure on the eyeballs. "
The middle ear contains the cochlea and semicircular canals.,(A) true (B) false,B,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in Figure 20.7, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. They also amplify the vibrations. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. "
__structure in the inner ear involved in maintaining balance,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,D,"Did you ever try to stand on one foot with your eyes closed? Try it and see what happens, but be careful! Its harder to keep your balance when you cant see. Your eyes obviously play a role in balance. But your ears play an even bigger role. The gymnast pictured below ( Figure 1.3) may not realize it, but her earsalong with her cerebellumare mostly responsible for her ability to perform on the balance beam. The parts of the ears involved in balance are the semicircular canals. Above, the semicircular canals are colored purple ( Figure 1.2). The canals contain liquid and are like the bottle of water pictured below ( Figure 1.4). When the bottle tips, the water surface moves up and down the sides of the bottle. When the body tips, the liquid in the semicircular canals moves up and down the sides of the canals. Tiny hair cells line the semicircular canals. Movement of the liquid inside the canals causes the hair cells to send nerve impulses. The nerve impulses travel to the cerebellum in the brain along the vestibular nerve. In response, the cerebellum sends commands to muscles to contract or relax so that the body stays balanced. "
__bundle of sensory neurons on the tongue that sense chemicals in food,(A) aretina (B) bhyperopia (C) cpupil (D) dsemicircular canal (E) etaste bud (F) fcochlea (G) gmyopia,E,"The sense of taste is controlled by sensory neurons on the tongue. They are grouped in bundles called taste buds. You can see taste buds on the tongue in Figure 20.16. Taste neurons sense chemicals in food. They can detect five different tastes: sweet, salty, sour, bitter, and umami, which is a meaty taste. When taste neurons sense chemicals, they send messages to the brain about them. The brain then decides what you are tasting. The sense of smell also involves sensory neurons that sense chemicals. These neurons are found in the nose, and they sense chemicals in the air. Unlike taste neurons, smell neurons can detect thousands of different odors. Your sense of smell plays a big role in your sense of taste. You can use your sense of taste alone to learn that a food is sweet. However, you have to use your sense of smell as well to learn that the food tastes like apple pie. "
Nerve cells that sense touch are most numerous in the skin.,(A) true (B) false,A,"Touch is the ability to sense pain, pressure, or temperature. Nerve cells that sense touch are found mainly in the skin. The skin on the palms, soles, face, and lips has the most neurons. Neurons that sense pain are also found inside the body inside the body in the tongue, joints, muscles, and other organs. Suppose you wanted to test the temperature of bath water before getting into the tub. You might stick one toe in the water. Neurons in the skin on your toe would sense the temperature of the water and send a message about it to the brain through the spinal cord. The brain would process the information. It might decide that the water is too hot and send a message to your muscles to pull your toe out of the water. "
Rods are light-sensing cells in the eye that can sense dim light.,(A) true (B) false,A,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
Why are human beings able to see in three dimensions?,(A) We have two eyes that face the same direction but are a few inches apart (B) Both of our eyes focus on the same object but from slightly different angles (C) The brain uses images from the two eyes to determine the distance to the object (D) all of the above,D,"Did you ever use 3-D glasses to watch a movie, like the teens in Figure 20.11? If you did, then you know that the glasses make images on the flat screen seem more realistic by giving them depth. The images seem to jump right out of the screen toward you. Unlike many other animals, human beings and other primates normally see the world around them in three dimen- sions. Thats because we have two eyes that face the same direction but are a few inches apart. Both eyes focus on the same object at the same time but from slightly different angles. The brain uses the different images from the two eyes to determine the distance to the object. Human beings and other primates also have the ability to see in color. We have special cells inside our eyes that can distinguish different wavelengths of visible light. Visible light is light in the range of wavelengths that the human eye can sense. The exact wavelength of visible light determines its color. "
"When light from an object reaches the human eye, it passes first through the",(A) pupil (B) cornea (C) lens (D) iris,B,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
Which statement about rods and cones in the human eye is false?,(A) Rods and cones are special light-sensing cells in the lens (B) Rods and cones send nerve impulses to the optic nerve (C) Cones sense different colors of light and rods sense dim light (D) none of the above,A,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
Myopia,(A) occurs when images focus in front of the retina (B) results when the eyeball is too short (C) can be corrected with convex lenses (D) all of the above,A,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
The middle ear,(A) contains three tiny bones called ossicles (B) passes vibrations from the eardrum to the inner ear (C) amplifies vibrations as they pass through (D) all of the above,D,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in Figure 20.7, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. They also amplify the vibrations. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. "
The human eye senses differences in the wavelengths of visible light as different,(A) brightnesses (B) intensities (C) shapes (D) colors,D,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
Nerve cells that sense touch are found mainly in the,(A) joints (B) muscles (C) heart (D) skin,D,"Touch is the ability to sense pain, pressure, or temperature. Nerve cells that sense touch are found mainly in the skin. The skin on the palms, soles, face, and lips has the most neurons. Neurons that sense pain are also found inside the body inside the body in the tongue, joints, muscles, and other organs. Suppose you wanted to test the temperature of bath water before getting into the tub. You might stick one toe in the water. Neurons in the skin on your toe would sense the temperature of the water and send a message about it to the brain through the spinal cord. The brain would process the information. It might decide that the water is too hot and send a message to your muscles to pull your toe out of the water. "
All endocrine glands secrete hormones into,(A) the bloodstream (B) local tissues (C) the digestive system (D) target cells,A,"An endocrine gland is a gland that secretes hormones into the bloodstream for transport around the body (instead of secreting hormones locally, like sweat glands in the skin). Major glands of the endocrine system are shown in Figure 20.17. The glands are the same in males and females except for the ovaries and testes. "
__messenger molecule released by an endocrine gland,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,D,"The endocrine system is a system of glands that release chemical messenger molecules into the blood stream. The messenger molecules are called hormones. Hormones act slowly compared with the rapid transmission of electrical impulses of the nervous system. Endocrine hormones must travel through the bloodstream to the cells they control, and this takes time. On the other hand, because endocrine hormones are released into the bloodstream, they travel to cells everywhere in the body. For a good visual introduction to the endocrine system, watch this short video: http MEDIA Click image to the left or use the URL below. URL: "
__pancreatic hormone that helps cells absorb glucose from the blood,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,C,"If you are a typical teenager, you like to eat. For your body to break down, absorb and spread the nutrients from your food throughout your body, your digestive system and endocrine system need to work together. The endocrine system sends hormones around your body to communicate between cells. Essentially, hormones are chemical messenger molecules. Digestive hormones are made by cells lining the stomach and small intestine. These hormones cross into the blood where they can affect other parts of the digestive system. Some of these hormones are listed below. Gastrin, which signals the secretion of gastric acid. Cholecystokinin, which signals the secretion of pancreatic enzymes. Secretin, which signals secretion of water and bicarbonate from the pancreas. Ghrelin, which signals when you are hungry. Gastric inhibitory polypeptide, which stops or decreases gastric secretion. It also causes the release of insulin in response to high blood glucose levels. "
The feedback loop that controls the production of thyroxin includes the,(A) pituitary gland (B) thyroid gland (C) hypothalamus (D) all of the above,D,"Endocrine hormones control many cell activities, so they are very important for homeostasis. But what controls the hormones? Most endocrine hormones are controlled by feedback loops. In a feedback loop, the hormone produced by a gland feeds back to control its own production by the gland. A feedback loop can be negative or positive. Most endocrine hormones are controlled by negative feedback loops. .Negative feedback occurs when rising levels of a hormone feed back to decrease secretion of the hormone or when falling levels of the hormone feed back to increase its secretion. You can see an example of a negative feedback loop in Figure 20.18. It shows how levels of thyroid hormones regulate the thyroid gland. This loop involves the hypothalamus and pituitary gland as well as the thyroid gland. Low levels of thyroid hormones in the blood cause the release of hormones by the hypothalamus and pituitary gland. These hormones stimulate the thyroid gland to secrete more hormones. The opposite happens with high levels of thyroid hormones in the blood. The hypothalamus and pituitary gland stop releasing hormones that stimulate the thyroid. "
Which endocrine gland secretes luteinizing hormone?,(A) pituitary gland (B) ovary (C) testis (D) two of the above,A,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
__any gland that secretes hormones into the bloodstream,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,E,"An endocrine gland is a gland that secretes hormones into the bloodstream for transport around the body (instead of secreting hormones locally, like sweat glands in the skin). Major glands of the endocrine system are shown in Figure 20.17. The glands are the same in males and females except for the ovaries and testes. "
__gland that secretes sex hormones,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,B,"There are several other endocrine glands. Find them in Figure 20.17 as you read about them below. The thyroid gland is a relatively large gland in the neck. Hormones secreted by the thyroid gland include thyroxin. Thyroxin increases the rate of metabolism in cells throughout the body. The pancreas is a large gland located near the stomach. Hormones secreted by the pancreas include insulin. Insulin helps cells absorb glucose from the blood. It also stimulates the liver to take up and store excess glucose. The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxygen and glucose going to the muscles. The gonads are glands that secrete sex hormones. Male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones stimulate the changes of puberty. They also control the production of sperm or eggs by the gonads. "
The hormone called ACTH,(A) acts on the thyroid gland (B) is secreted by pituitary gland (C) stimulates the secretion of sex hormones (D) causes cells to make proteins and grow,B,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
__part of the brain that secretes hormones affecting the pituitary gland,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,A,"The hypothalamus is actually part of the brain, but it also secretes hormones. Some of its hormones go directly to the pituitary gland in the endocrine system. These hypothalamus hormones tell the pituitary to either secrete or stop secreting its hormones. In this way, the hypothalamus provides a link between the nervous and endocrine systems. The hypothalamus also produces hormones that directly regulate body processes. For example, it produces antid- iuretic hormone. This hormone travels to the kidneys and stimulates them to conserve water by producing more concentrated urine. "
Which statement about gigantism is true?,(A) It is characterized by excessive growth during childhood (B) It occurs when blood levels of thyroxin are too high (C) It may be caused by a tumor in the thyroid gland (D) all of the above,A,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
__pituitary hormone that stimulates the mammary glands to produce milk,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,F,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
__master gland of the endocrine system,(A) ahypothalamus (B) bgonad (C) cinsulin (D) dhormone (E) eendocrine gland (F) fprolactin (G) gpituitary gland,G,"An endocrine gland is a gland that secretes hormones into the bloodstream for transport around the body (instead of secreting hormones locally, like sweat glands in the skin). Major glands of the endocrine system are shown in Figure 20.17. The glands are the same in males and females except for the ovaries and testes. "
Which structure provides a link between the nervous and endocrine systems?,(A) pituitary gland (B) hypothalamus (C) adrenal gland (D) thyroid gland,B,"The endocrine system is a system of glands that release chemical messenger molecules into the blood stream. The messenger molecules are called hormones. Hormones act slowly compared with the rapid transmission of electrical impulses of the nervous system. Endocrine hormones must travel through the bloodstream to the cells they control, and this takes time. On the other hand, because endocrine hormones are released into the bloodstream, they travel to cells everywhere in the body. For a good visual introduction to the endocrine system, watch this short video: http MEDIA Click image to the left or use the URL below. URL: "
Most pituitary hormones control,(A) other endocrine glands (B) the hypothalamus (C) body cells (D) the brain,A,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
The pituitary hormone called follicle-stimulating hormone stimulates the,(A) testes to produce sperm (B) hair follicles to grow hair (C) ovaries to secrete estrogen (D) two of the above,A,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
Which gland secretes growth hormone?,(A) adrenal gland (B) thyroid gland (C) ovary (D) pituitary gland,D,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
Follicle-stimulating hormone is secreted by the gonads.,(A) true (B) false,B,"There are several other endocrine glands. Find them in Figure 20.17 as you read about them below. The thyroid gland is a relatively large gland in the neck. Hormones secreted by the thyroid gland include thyroxin. Thyroxin increases the rate of metabolism in cells throughout the body. The pancreas is a large gland located near the stomach. Hormones secreted by the pancreas include insulin. Insulin helps cells absorb glucose from the blood. It also stimulates the liver to take up and store excess glucose. The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxygen and glucose going to the muscles. The gonads are glands that secrete sex hormones. Male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones stimulate the changes of puberty. They also control the production of sperm or eggs by the gonads. "
The thymus gland is part of the endocrine system.,(A) true (B) false,A,"An endocrine gland is a gland that secretes hormones into the bloodstream for transport around the body (instead of secreting hormones locally, like sweat glands in the skin). Major glands of the endocrine system are shown in Figure 20.17. The glands are the same in males and females except for the ovaries and testes. "
Endocrine hormones influence target cells by,(A) acting as enzymes and speeding up chemical reactions in the cells (B) absorbing glucose and actively transporting it into the cells (C) binding with proteins on the surface of the cells (D) creating negative feedback loops with the cells,C,"A target cell is the type of cell on which a given endocrine hormone has an effect. A target cell is affected by a given hormone because it has proteins on its surface to which the hormone can bind. When the hormone binds to target cell proteins, it causes changes inside the cell. For example, binding of the hormone might cause the release of enzymes inside the cell. The enzymes then influence cell processes. "
The output of most endocrine hormones is controlled by positive feedback loops.,(A) true (B) false,B,"Endocrine hormones control many cell activities, so they are very important for homeostasis. But what controls the hormones? Most endocrine hormones are controlled by feedback loops. In a feedback loop, the hormone produced by a gland feeds back to control its own production by the gland. A feedback loop can be negative or positive. Most endocrine hormones are controlled by negative feedback loops. .Negative feedback occurs when rising levels of a hormone feed back to decrease secretion of the hormone or when falling levels of the hormone feed back to increase its secretion. You can see an example of a negative feedback loop in Figure 20.18. It shows how levels of thyroid hormones regulate the thyroid gland. This loop involves the hypothalamus and pituitary gland as well as the thyroid gland. Low levels of thyroid hormones in the blood cause the release of hormones by the hypothalamus and pituitary gland. These hormones stimulate the thyroid gland to secrete more hormones. The opposite happens with high levels of thyroid hormones in the blood. The hypothalamus and pituitary gland stop releasing hormones that stimulate the thyroid. "
Males and females have the same endocrine glands except for the,(A) thyroid gland (B) pituitary gland (C) adrenal glands (D) gonads,D,"An endocrine gland is a gland that secretes hormones into the bloodstream for transport around the body (instead of secreting hormones locally, like sweat glands in the skin). Major glands of the endocrine system are shown in Figure 20.17. The glands are the same in males and females except for the ovaries and testes. "
What happens when the level of thyroxin rises in the blood?,(A) The pituitary gland releases thyroid-stimulating hormone (B) The thyroid gland starts releasing more hormones (C) The level of TSH in the blood falls (D) two of the above,C,"Endocrine hormones travel throughout the body in the blood. However, each endocrine hormone affects only certain cells, called target cells. "
Type 1 diabetes occurs when the immune system attacks cells of the adrenal glands.,(A) true (B) false,B,"Type 1 diabetes is caused by the immune system attacking and destroying normal cells of the pancreas. As a result, the cells can no longer produce insulin. Why the immune system acts this way is not known for certain. Its possible that a virus may trigger the attack. This type of diabetes usually develops in childhood or adolescence. At present, there is no known way to prevent the development of type 1 diabetes. However, it is a treatable disease. Treatment of type 1 diabetes includes: taking several insulin injections every day or using an insulin pump (see Figure 21.7). monitoring blood glucose levels several times a day. eating a healthy diet that spreads out carbohydrate intake throughout the day. regular physical activity, which helps the body use insulin more efficiently. regular medical checkups. "
The hormone adrenaline prepares the body for emergencies.,(A) true (B) false,A,"There are several other endocrine glands. Find them in Figure 20.17 as you read about them below. The thyroid gland is a relatively large gland in the neck. Hormones secreted by the thyroid gland include thyroxin. Thyroxin increases the rate of metabolism in cells throughout the body. The pancreas is a large gland located near the stomach. Hormones secreted by the pancreas include insulin. Insulin helps cells absorb glucose from the blood. It also stimulates the liver to take up and store excess glucose. The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxygen and glucose going to the muscles. The gonads are glands that secrete sex hormones. Male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones stimulate the changes of puberty. They also control the production of sperm or eggs by the gonads. "
Endocrine hormones travel more slowly than nerve impulses.,(A) true (B) false,A,"Endocrine hormones travel throughout the body in the blood. However, each endocrine hormone affects only certain cells, called target cells. "
Endocrine hormones affect only nearby cells.,(A) true (B) false,B,"Endocrine hormones travel throughout the body in the blood. However, each endocrine hormone affects only certain cells, called target cells. "
The pineal gland is part of the endocrine system.,(A) true (B) false,A,"The hypothalamus is actually part of the brain, but it also secretes hormones. Some of its hormones go directly to the pituitary gland in the endocrine system. These hypothalamus hormones tell the pituitary to either secrete or stop secreting its hormones. In this way, the hypothalamus provides a link between the nervous and endocrine systems. The hypothalamus also produces hormones that directly regulate body processes. For example, it produces antid- iuretic hormone. This hormone travels to the kidneys and stimulates them to conserve water by producing more concentrated urine. "
All hormones released by the hypothalamus control the pituitary gland.,(A) true (B) false,B,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
The pituitary gland is located in the neck.,(A) true (B) false,B,The pea-sized pituitary gland is just below the hypothalamus and attached directly to it. The pituitary receives hormones from the hypothalamus. It also secretes its own hormones. Most pituitary hormones control other endocrine glands. Thats why the pituitary gland is called the master gland of the endocrine system. Table Pituitary Hormone Adrenocorticotropic (ACTH) hormone Target Glands/Cells adrenal glands Thyroid-stimulating (TSH) Growth hormone (GH) hormone thyroid gland Follicle-stimulating (FSH) hormone body cells ovaries or testes Luteinizing hormone (LH) ovaries or testes Prolactin (PRL) mammary glands Effects(s) Stimulates the cortex (outer layer) of the adrenal glands to secrete their hormones Stimulates the thyroid gland to se- crete its hormones Stimulates body cells to make pro- teins and grow Stimulates the ovaries to develop mature eggs; stimulates the testes to produce sperm Stimulates the ovaries or testes to secrete sex hormones; stimulates the ovaries to release eggs Stimulates the mammary glands to produce milk 
Growth hormone stimulates cells to make proteins.,(A) true (B) false,A,"A target cell is the type of cell on which a given endocrine hormone has an effect. A target cell is affected by a given hormone because it has proteins on its surface to which the hormone can bind. When the hormone binds to target cell proteins, it causes changes inside the cell. For example, binding of the hormone might cause the release of enzymes inside the cell. The enzymes then influence cell processes. "
Luteinizing hormone is secreted by the gonads.,(A) true (B) false,B,"There are several other endocrine glands. Find them in Figure 20.17 as you read about them below. The thyroid gland is a relatively large gland in the neck. Hormones secreted by the thyroid gland include thyroxin. Thyroxin increases the rate of metabolism in cells throughout the body. The pancreas is a large gland located near the stomach. Hormones secreted by the pancreas include insulin. Insulin helps cells absorb glucose from the blood. It also stimulates the liver to take up and store excess glucose. The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxygen and glucose going to the muscles. The gonads are glands that secrete sex hormones. Male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones stimulate the changes of puberty. They also control the production of sperm or eggs by the gonads. "
The disease called genital warts is,(A) an infectious disease (B) caused by the virus HPV (C) spread through sexual contact (D) all of the above,D,"Genital warts are an STI caused by human papilloma virus, or HPV. They are one of the most common STIs in teenagers. HPV infections cannot be cured. But a new vaccine called Gardasil can prevent most HPV infections in females. Many doctors recommend that females between the ages of 9 and 26 years receive the vaccine. Preventing HPV infections in females is important because HPV can also cause cancer of the cervix. A related herpes virus causes cold sores on the lips ( Figure 1.2). Both viruses cause painful blisters. In the case of genital herpes, the blisters are on the penis or around the vaginal opening. The blisters go away on their own, but the virus remains in the body. The blisters may come back repeatedly, especially when a person is under stress. There is no cure for genital herpes. But drugs can help prevent or shorten outbreaks. Researchers are trying to find a vaccine to prevent genital herpes. Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. HIV stands for ""human immunodeficiency virus."" It is the virus that causes AIDS. HIV and AIDS are described in a previous concept. HIV can spread through sexual contact. It can also spread through body fluids such as blood. There is no cure for HIV infection, and AIDS can cause death, although AIDS can be delayed for several years with medication. Researchers are trying to find a vaccine to prevent HIV infection. "
The common cold is,(A) an infectious disease (B) caused by bacteria (C) spread by a vector (D) two of the above,A,"No doubt youve had the common cold. When you did, you probably had respiratory system symptoms. For example, you may have had a stuffy nose that made it hard to breathe. While you may feel miserable when you have a cold, it is generally a relatively mild disease. Many other respiratory system diseases are more serious. "
Types of pathogens that cause human diseases include,(A) bacteria (B) fungi (C) protozoa (D) all of the above,D,"There are several types of pathogens that cause diseases in human beings. They include bacteria, viruses, fungi, and protozoa. The different types are described in Table 21.1. The table also lists several diseases caused by each type of pathogen. Many infectious diseases caused by these pathogens can be cured with medicines. For example, antibiotic drugs can cure most diseases caused by bacteria. "
Diseases caused by bacteria include,(A) malaria (B) syphilis (C) measles (D) two of the above,B,"There are also ways that bacteria can be harmful to humans and other animals. Bacteria are responsible for many types of human illness ( Figure 1.1), including: Strep throat Tuberculosis Pneumonia Leprosy Lyme disease Luckily most of these can be treated with antibiotics, which kill the bacteria. It is important that when a medical doctor prescribes antibiotics for you, you take the medicine exactly as the doctor tells you. You need to make sure the bacteria is killed. "
Diseases that can spread by airborne droplets include,(A) ringworm (B) influenza (C) tinea (D) giardiasis,B,"Respiratory diseases are diseases of the lungs, bronchial tubes, trachea, nose, and throat ( Figure 1.1). These diseases can range from a mild cold to a severe case of pneumonia. Respiratory diseases are common. Many are easily treated, while others may cause severe illness or death. Some respiratory diseases are caused by bacteria or viruses, while others are caused by environmental pollutants, such as tobacco smoke. Some diseases are genetic and, therefore, are inherited. This boy is suffering from whooping cough (also known as pertussis), which gets its name from the loud whooping sound that is made when the person inhales during a coughing fit. "
Which disease can potentially be cured with antibiotic drugs?,(A) influenza (B) athletes foot (C) chicken pox (D) tuberculosis,D,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
Which type of pathogen causes AIDS?,(A) bacterium (B) virus (C) fungus (D) protozoan,B,"AIDS is not really a single disease. It is a set of symptoms and other diseases. It results from years of damage to the immune system by HIV. AIDS occurs when helper T cells fall to a very low level, making it difficult for the affected person to fight various diseases and other infections. These people develop infections or cancers that people with a healthy immune systems can easily resist. These diseases are usually the cause of death of people with AIDS. The first known cases of AIDS occurred in 1981. Since then, AIDS has led to the deaths of more than 35 million people worldwide. Many of them were children. The greatest number of deaths occurred in Africa. It is also where medications to control HIV are least available. There are currently more people infected with HIV in Africa than any other part of the world. Well over 30 million people are living with HIV worldwide. "
The vector that spreads malaria is a,(A) tick (B) spider (C) mosquito (D) none of the above,C,"Still other pathogens are spread by vectors. A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects, such as ticks and mosquitoes. These insects tend to transfer protozoan or viral parasites. When an insect bites an infected person or animal, it picks up the pathogen. Then the pathogen travels to the next person or animal it bites. Ticks carry the bacteria that cause Lyme disease. Mosquitoes ( Figure serious symptoms may develop. Other diseases spread by mosquitoes include Dengue Fever and Yellow Fever. The first case of West Nile virus in North America occurred in 1999. Within just a few years, the virus had spread throughout most of the United States. Birds as well as humans can be infected with the virus. Birds often fly long distances. This is one reason why West Nile virus spread so quickly. "
An example of a pathogen that spreads through water is,(A) Herpes simplex (B) Giardia lamblia (C) HPV (D) two of the above,B,"Different pathogens spread in different ways. Some are easy to catch. Others are much less contagious. Some pathogens spread through food or water. When harmful bacteria contaminate food, they cause foodborne illness, commonly called food poisoning. An example of a pathogen that spreads through water is the protozoan named Giardia lamblia, described in Table 21.1. It causes a disease called giardiasis. Some pathogens spread through sexual contact. In the U.S., the pathogen most commonly spread this way is HPV, or human papillomavirus. It may cause genital warts and certain types of cancer. A vaccine can prevent the spread of this pathogen. Many pathogens spread by droplets in the air. Droplets are released when a person coughs or sneezes, as you can see in Figure 21.2. The droplets may be loaded with pathogens. Other people may get sick if they breathe in the pathogens on the droplets. Viruses that cause colds and flu can spread this way. Other pathogens spread when they are deposited on objects or surfaces. The fungus that causes athletes food spreads this way. For example, you might pick up the fungus from the floor of a public shower. You can also pick up viruses for colds and flu from doorknobs and other commonly touched surfaces. Still other pathogens are spread by vectors. A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects such as ticks or mosquitoes. They pick up pathogens when they bite an infected animal and then transmit the pathogens to the next animal they bite. Ticks spread the bacteria that cause Lyme disease. Mosquitoes spread the protozoa that cause malaria. "
All of the following diseases can be prevented with vaccines except,(A) whooping cough (B) mumps (C) chicken pox (D) the common cold,D,"Getting the recommended vaccinations can help prevent diseases, such as whooping cough and flu. In fact, a yearly flu vaccine is recommended for everyone who is at least 6 months of age. The flu vaccine is especially important for people who are at high risk of developing serious complications (like pneumonia) if they get sick with the flu. People who have certain medical conditions including asthma, diabetes, and chronic lung disease, pregnant women, and people younger than 5 years (and especially those younger than 2), and people 65 years and older should also make sure they get the yearly flu vaccine. Seeking medical help for diseases like asthma can help stop the disease from getting worse. If you are unsure if you should go to the doctor, call the doctors office and ask. "
Which human infectious disease can be prevented with a vaccine?,(A) food poisoning (B) candidiasis (C) genital warts (D) syphilis,C,"What can you do to avoid infectious diseases? Eating well and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. Vaccines are available for some infectious diseases. For example, there are vaccines to prevent measles, mumps, whooping cough, and chicken pox. These vaccines are recommended for infants and young children. You can also take the following steps to avoid picking up pathogens or spreading them to others. Watch this video for additional information on preventing the spread of infectious diseases:  MEDIA Click image to the left or use the URL below. URL:  Wash your hands often with soap and water. Spend at least 20 seconds scrubbing with soap. See Figure 21.3 for effective hand washing tips. Avoid touching your eyes, nose, or mouth with unwashed hands. Avoid close contact with people who are sick. This includes kissing, hugging, shaking hands, and sharing cups or eating utensils. Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands. Disinfect frequently touched surfaces, such as keyboards and doorknobs, especially if someone is sick. Stay home when you are sick. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. For example, you can wear long sleeves and long pants to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. "
The common cold can be spread by pathogens,(A) in airborne droplets (B) on objects or surfaces (C) in contaminated water (D) two of the above,D,"Different pathogens spread in different ways. Some pathogens spread through food. They cause food borne illnesses, which are discussed in a previous concept. Some pathogens spread through water. Giardia lamblia is one example. Water can be boiled to kill Giardia and most other pathogens. Several pathogens spread through sexual contact. HIV is one example, which is discussed in the next concept. Other pathogens that spread through sexual contact are discussed in a separate concept. Many pathogens that cause respiratory diseases spread by droplets in the air. Droplets are released when a person sneezes or coughs. Thousands of tiny droplets are released when a person sneezes ( Figure 1.5). Each droplet can contain thousands of pathogens. Viruses that cause colds and the flu can spread in this way. You may get sick if you breathe in the pathogens. As this picture shows, thousands of tiny droplets are released into the air when a person sneezes. Each droplet may carry thousands of pathogens. You cant normally see the droplets from a sneeze because they are so small. However, you can breathe them in, along with any pathogens they carry. This is how many diseases of the respiratory system are spread. "
Schistosoma is a human parasite that is spread by a vector..,(A) true (B) false,B,"Many human diseases are caused by protists. Most of them are caused by protozoa. They are parasites that invade and live in the human body. The parasites get a place to live and nutrients from the human host. In return, they make the host sick. Examples of human diseases caused by protozoa include giardiasis and malaria. Protozoa that cause giardiasis are spread by contaminated food or water. They live inside the intestine. They may cause abdominal pain, fever, and diarrhea. Protozoa that cause malaria are spread by a vector. They enter the blood through the bite of an infected mosquito. They live inside red blood cells. They cause overall body pain, fever, and fatigue. Malaria kills several million people each year. Most of the deaths occur in children. "
An example of a bacterium that may cause human disease is Escherichia coli.,(A) true (B) false,A,"You have ten times as many bacterial cells as human cells in your body. Luckily for you, most of these bacteria are harmless. However, some of them can cause disease. Any organism that causes disease is called a pathogen. Diseases caused by bacterial pathogens include food poisoning, strep throat, and Lyme disease. Bacteria that cause disease may spread directly from person to person. For example, they may spread when people shake hands with, or sneeze on, other people. Bacteria may also spread through food, water, or objects that have become contaminated with them. Some bacteria are spread by vectors. A vector is an organism that spreads bacteria or other pathogens. Most vectors are animals, commonly insects. For example, deer ticks like the one in Figure 8.13 spread Lyme disease. Ticks carry Lyme disease bacteria from deer to people when they bite them. "
Human viral infections include tetanus and measles.,(A) true (B) false,B,"Viruses cause many human diseases. In addition to the flu and the common cold, viruses cause rabies, diarrheal diseases, AIDS, cold sores, and many other diseases ( Figure 1.2). Viral diseases range from mild to fatal. Cold sores are caused by a herpes virus. "
A common human fungal infection is genital herpes.,(A) true (B) false,B,"Several common human diseases are caused by fungi. They include ringworm and athletes foot, both shown in Figure 9.15. Ringworm isnt caused by a worm. Its a skin infection by a fungus that leads to a ring-shaped rash. The rash may occur on the head, neck, trunk, arms, or legs. Athletes foot is caused by the same fungus as ringworm. But in athletes foot, the fungus infects the skin between the toes. Athletes foot is the second most common skin disease in the U.S. "
"When you cough or sneeze, you should cover your mouth and nose with your hand.",(A) true (B) false,B,"Do not go to school or to other public places when you are sick. You risk spreading your illness to other people. You may also get even sicker if you catch something else. Do not share food and other things that go in the mouth, as in guzzling milk from the carton or double dipping chips. You never know what pathogens can be lurking around. Cover your mouth with a tissue when you cough or sneeze and to dispose of the tissue yourself. No time to grab a tissue. Cough or sneeze into the inside of your elbow instead of your hands. "
The best way to prevent diseases spread by vectors to is avoid contact with the vectors.,(A) true (B) false,A,"You can also take steps to avoid pathogens in the first place. The best way to avoid pathogens is to wash your hands often. You should wash your hands after using the bathroom or handling raw meat or fish. You should also wash your hands before eating or preparing food. In addition, you should also wash the food that your eat, and the utensils and countertop where food is prepared. In addition, you should wash your hands after being around sick people. The correct way to wash your hands is demonstrated below ( Figure 1.1). If soap and water arent available, use some hand sanitizer. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. Recall that a vector is an organism that carries pathogens from one person or animal to another. For example, ticks and mosquitoes are vectors, so you should wear long sleeves and long pants when appropriate to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. Many infectious diseases can be prevented with vaccinations. Immunization can drastically reduce your chances of contracting many diseases. You will read more about vaccinations in another concept. Vaccinations can help prevent measles, mumps, chicken pox, and several other diseases. If you do develop an infectious disease, try to avoid infecting others. Stay home from school until you are well. Also, take steps to keep your germs to yourself. Cover your mouth and nose with a tissue when you sneeze or cough, Watching the news will allow you to make informed decisions. If an outbreak of bad beef due to a bacterial infection is in the news, dont buy beef for a while. If tomatoes are making people sick, dont eat tomatoes until the outbreak is over. If a place has an unhealthy water supply, boil the water or drink bottled water. Local news can tell you of restaurants to avoid due to unhealthy conditions. And so on. "
Travelers diarrhea is generally caused by protozoa.,(A) true (B) false,A,"Many human diseases are caused by protists. Most of them are caused by protozoa. They are parasites that invade and live in the human body. The parasites get a place to live and nutrients from the human host. In return, they make the host sick. Examples of human diseases caused by protozoa include giardiasis and malaria. Protozoa that cause giardiasis are spread by contaminated food or water. They live inside the intestine. They may cause abdominal pain, fever, and diarrhea. Protozoa that cause malaria are spread by a vector. They enter the blood through the bite of an infected mosquito. They live inside red blood cells. They cause overall body pain, fever, and fatigue. Malaria kills several million people each year. Most of the deaths occur in children. "
Infectious diseases are contagious because they are caused by pathogens.,(A) true (B) false,A,"Has this ever happened to you? A student sitting next to you in class has a cold. The other student is coughing and sneezing, but you feel fine. Two days later, you come down with a cold, too. Diseases like colds are contagious. Contagious diseases are also called infectious diseases. An infectious disease is a disease that spreads from person to person. Infectious diseases are caused by pathogens. A pathogen is a living thing or virus that causes disease. Pathogens are commonly called germs. They can travel from one person to another. "
You can pick up the virus that causes the common cold from an object such as a doorknob.,(A) true (B) false,A,"Do not go to school or to other public places when you are sick. You risk spreading your illness to other people. You may also get even sicker if you catch something else. Do not share food and other things that go in the mouth, as in guzzling milk from the carton or double dipping chips. You never know what pathogens can be lurking around. Cover your mouth with a tissue when you cough or sneeze and to dispose of the tissue yourself. No time to grab a tissue. Cough or sneeze into the inside of your elbow instead of your hands. "
The proper way to wash your hands is to scrub with soap for at least 20 seconds.,(A) true (B) false,A,"Washing your hands often, especially after sneezing, coughing, or blowing your nose, helps to protect you and others from diseases. Washing your hands for 20 seconds with soap and warm water can help prevent colds and flu. In one respect, you can think of hand washing as a survival skill. Some viruses and bacteria can live from 20 minutes to two hours or more on surfaces like cafeteria tables, doorknobs, and desks. Washing your hands often can remove many of these pathogens. Never touch your mouth, nose, or eyes without washing your hands. "
A disease that can potentially be cured with antibiotics is strep throat.,(A) true (B) false,A,"There are also ways that bacteria can be harmful to humans and other animals. Bacteria are responsible for many types of human illness ( Figure 1.1), including: Strep throat Tuberculosis Pneumonia Leprosy Lyme disease Luckily most of these can be treated with antibiotics, which kill the bacteria. It is important that when a medical doctor prescribes antibiotics for you, you take the medicine exactly as the doctor tells you. You need to make sure the bacteria is killed. "
Athletes foot is a common infectious disease caused by protozoa.,(A) true (B) false,B,"Other pathogens spread when they get on objects or surfaces. A fungus may spread in this way. For example, you can pick up the fungus that causes athletes foot by wearing shoes that an infected person has worn. You can also pick up this fungus from the floor of a public shower or other damp areas. After acne, athletes foot is the most common skin disease in the United States. Therefore, the chance of coming in contact with the fungus in one of these ways is fairly high. Bacteria that cause the skin disease impetigo, which causes blisters, can spread when people share towels or clothes. The bacteria can also spread through direct skin contact in sports like wrestling. "
__any organism that carries pathogens from one organism to another,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,D,"Still other pathogens are spread by vectors. A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects, such as ticks and mosquitoes. These insects tend to transfer protozoan or viral parasites. When an insect bites an infected person or animal, it picks up the pathogen. Then the pathogen travels to the next person or animal it bites. Ticks carry the bacteria that cause Lyme disease. Mosquitoes ( Figure serious symptoms may develop. Other diseases spread by mosquitoes include Dengue Fever and Yellow Fever. The first case of West Nile virus in North America occurred in 1999. Within just a few years, the virus had spread throughout most of the United States. Birds as well as humans can be infected with the virus. Birds often fly long distances. This is one reason why West Nile virus spread so quickly. "
__any disease that is caused by pathogens,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,E,"There are several types of pathogens that cause diseases in human beings. They include bacteria, viruses, fungi, and protozoa. The different types are described in Table 21.1. The table also lists several diseases caused by each type of pathogen. Many infectious diseases caused by these pathogens can be cured with medicines. For example, antibiotic drugs can cure most diseases caused by bacteria. "
__type of drug that is used to cure bacterial diseases,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,G,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
__substance that is used to prevent certain infectious diseases,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,B,"What can you do to avoid infectious diseases? Eating well and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. Vaccines are available for some infectious diseases. For example, there are vaccines to prevent measles, mumps, whooping cough, and chicken pox. These vaccines are recommended for infants and young children. You can also take the following steps to avoid picking up pathogens or spreading them to others. Watch this video for additional information on preventing the spread of infectious diseases:  MEDIA Click image to the left or use the URL below. URL:  Wash your hands often with soap and water. Spend at least 20 seconds scrubbing with soap. See Figure 21.3 for effective hand washing tips. Avoid touching your eyes, nose, or mouth with unwashed hands. Avoid close contact with people who are sick. This includes kissing, hugging, shaking hands, and sharing cups or eating utensils. Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands. Disinfect frequently touched surfaces, such as keyboards and doorknobs, especially if someone is sick. Stay home when you are sick. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. For example, you can wear long sleeves and long pants to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. "
__type of organisms that cause malaria and giardiasis,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,F,"Many human diseases are caused by protists. Most of them are caused by protozoa. They are parasites that invade and live in the human body. The parasites get a place to live and nutrients from the human host. In return, they make the host sick. Examples of human diseases caused by protozoa include giardiasis and malaria. Protozoa that cause giardiasis are spread by contaminated food or water. They live inside the intestine. They may cause abdominal pain, fever, and diarrhea. Protozoa that cause malaria are spread by a vector. They enter the blood through the bite of an infected mosquito. They live inside red blood cells. They cause overall body pain, fever, and fatigue. Malaria kills several million people each year. Most of the deaths occur in children. "
__any organism or virus that causes disease in another living thing,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,A,An infectious disease is a disease that is caused by a pathogen. A pathogen is an organism or virus that causes disease in another living thing. Pathogens are commonly called germs. Watch this dramatic video for an historic perspective on infectious diseases and their causes:  . MEDIA Click image to the left or use the URL below. URL: 
__particle that reproduces by taking over living cells,(A) apathogen (B) bvaccine (C) cvirus (D) dvector (E) einfectious disease (F) fprotozoa (G) gantibiotic,C,"Viruses infect a variety of organisms, including plants, animals, and bacteria, injecting its genetic material into a cell of the host organism. Once inside the host cell, they use the cells own ATP (energy), ribosomes, enzymes, and other cellular parts to make copies of themselves. The host cell makes a copy of the viral DNA and produces viral proteins. These are then packaged into new viruses. So viruses cannot replicate or reproduce on their own; they rely on a host cell to make additional viruses. "
Cancer in childhood is rare.,(A) true (B) false,A,"Cancer occurs most often in adults, especially adults over the age of 50. The most common types of cancer in adults differ between males and females. The most common type of cancer in adult males is cancer of the prostate gland. The prostate gland is part of the male reproductive system. About one third of all cancers in men are prostate cancers. The most common type of cancer in adult females is cancer of the breast. About one third of all cancers in women are breast cancers. In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. Childhood cancer is rare. The main type of cancer in children is leukemia. It makes up about one third of all childhood cancers. It occurs when the body makes abnormal white blood cells. "
Warning signs of cancer include difficulty swallowing.,(A) true (B) false,A,"Many cases of cancer can be cured if the cancer is diagnosed and treated early. Treatment often involves removing a tumor with surgery. This may be followed by other types of treatments. These treatments may include drugs and radiation, both of which target and kill cancer cells. Its important to know the warning signs of cancer so it can be diagnosed as early as possible. Having warning signs doesnt mean that you have cancer, but you should check with a doctor to be sure. Warning signs of cancer include: a change in bowel or bladder habits. a sore that doesnt heal. unusual bleeding or discharge. a lump in the breast or elsewhere. frequent, long-term indigestion. difficulty swallowing. obvious changes in a wart or mole. persistent cough or hoarseness. "
Surgery is the only way to treat cancer.,(A) true (B) false,B,"Many cases of cancer can be cured if the cancer is diagnosed and treated early. Treatment often involves removing a tumor with surgery. This may be followed by other types of treatments. These treatments may include drugs and radiation, both of which target and kill cancer cells. Its important to know the warning signs of cancer so it can be diagnosed as early as possible. Having warning signs doesnt mean that you have cancer, but you should check with a doctor to be sure. Warning signs of cancer include: a change in bowel or bladder habits. a sore that doesnt heal. unusual bleeding or discharge. a lump in the breast or elsewhere. frequent, long-term indigestion. difficulty swallowing. obvious changes in a wart or mole. persistent cough or hoarseness. "
Type 1 diabetes usually develops in childhood or adolescence.,(A) true (B) false,A,"Type 1 diabetes occurs when the immune system attacks normal cells of the pancreas. Since the cells in the pancreas are damaged, the pancreas cannot make insulin. Type 1 diabetes usually develops in childhood or adolescence. People with type 1 diabetes must frequently check the sugar in their blood. They use a meter to monitor their blood sugar ( Figure 1.1). Whenever their blood sugar starts to get too high, they need a shot of insulin. The insulin brings their blood sugar back to normal. There is no cure for type 1 diabetes. Therefore, insulin shots must be taken for life. Most people with this type of diabetes learn how to give themselves insulin shots. This is one type of meter used by people with diabetes to measure their blood sugar. Modern meters like this one need only a drop of blood and take less than a minute to use. "
Your risk of developing type 2 diabetes is greater if you are overweight.,(A) true (B) false,A,"Type 2 diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body cant use it. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before. You can greatly reduce your risk of developing type 2 diabetes by maintaining a healthy body weight. Some cases of type 2 diabetes can be cured with weight loss. However, most people with the disease need to take medicine to control their blood glucose. Regular exercise and balanced eating also help. Like people with type 1 diabetes, people with type 2 diabetes must frequently check their blood glucose. "
"In multiple sclerosis, the immune system attacks the joints.",(A) true (B) false,B,"An autoimmune disease is a disease in which the immune system attacks the bodys own cells. Why this happens is not known for certain, but a combination of genetic and environmental factors are likely to be responsible. Type 1 diabetes is an example of an autoimmune disease. In this case, the immune system attacks cells of the pancreas. Two other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain that gradually get worse over time. In rheumatoid arthritis, the immune system attacks joints. This causes joint damage and pain. These diseases cant be prevented and have no known cure. However, they can be treated with medicines that weaken the immune systems attack on normal cells. "
Hay fever is a noninfectious disease characterized by a high fever.,(A) true (B) false,B,"An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy. Did you ever hear of hay fever? Its not really a fever at all. Its an allergy to plant pollens. People with this type of allergy have symptoms such as watery eyes, sneezing, and a runny nose. A common cause of hay fever is the pollen of ragweed. Many people are also allergic to poison ivy ( Figure 1.2). Skin contact with poison ivy leads to an itchy rash in people who are allergic to the plant. Ragweed is a common roadside weed found throughout the United States. Many people are allergic to its pollen. Some people are allergic to certain foods. Nuts and shellfish are common causes of food allergies. Other common causes of allergies include: Drugs, such as penicillin. Mold. Dust. The dead skin cells of dogs and cats, called dander. Stings of wasps and bees. Most allergies can be treated with medicines. Medicines used to treat allergies include antihistamines and corticos- teroids. These medicines help control the immune system when it attacks an allergen. Sometimes, allergies cause severe symptoms, a condition known as anaphylaxis. For example, they may cause the throat to swell so it is hard to breathe. Severe allergies may be life threatening. They require emergency medical care. "
__mass of abnormal tissue formed by cancer cells,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,G,"Cancer is a disease in which cells divide out of control. Normally, the body has ways to prevent cells from dividing out of control. However, in the case of cancer, these ways fail. The rapidly dividing cells may form a mass of abnormal tissue called a tumor. This is illustrated in Figure 21.4. Watch this video for an animated introduction to cancer:  . MEDIA Click image to the left or use the URL below. URL:  As a tumor increases in size, it may harm normal tissues around it. Sometimes cancer cells break away from a tumor. If they enter the bloodstream, they are carried throughout the body. Then the cells may start growing in other tissues. This is usually how cancer spreads from one part of the body to another. Once this happens, cancer is very hard to stop. "
__any disease that is not contagious,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,D,"Noninfectious diseases cant be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If youre born with these conditions, you must learn how to manage the symptoms. Examples of conditions caused by environmental or lifestyle factors include heart disease and skin cancer. We cant change our genetic codes, but there are plenty of ways to prevent other noninfectious diseases. For example, cutting down on exposure to cigarette smoke and the suns rays will prevent certain types of cancer. It is a fact that most chronic noninfectious diseases can be prevented. The chronic noninfectious diseases that cause the most deaths in many developed countries are largely preventable. These diseases are heart disease, stroke, diabetes and cancer, and though they do have some genetic components, they also have many lifestyle components. For example, some cancers have genetic risks, but people at high risk for cancers can have screening examinations to catch them early or sometimes can take other steps to prevent the cancers. Heart disease, stroke and diabetes are mostly linked to lifestyle choices, even when family history puts a person at higher risk for the diseases. Most allergies can be prevented by avoiding the substances that cause them. For example, you can avoid pollens by staying indoors as much as possible. You can learn to recognize plants like poison ivy and not touch them. A good way to remember how to avoid poison ivy is ""leaves of three, let it be."" Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens, which are the substances that cause an allergic reaction. After many months or years of shots, the immune system gets used to the allergens and no longer responds to them. Type 1 diabetes and other autoimmune diseases cannot be prevented. But choosing a healthy lifestyle can help prevent type 2 diabetes. Getting plenty of exercise, avoiding high-fat foods, and staying at a healthy weight can reduce the risk of developing this type of diabetes. This is especially important for people who have family members with the disease. Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens, which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure 1.1). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesnt matter whether the radiation comes from tanning lamps or the sun. Overall, people in many developed countries are contributing to higher rates of noninfectious diseases (heart disease, stroke, diabetes and cancer) by taking advantage of technology and social environments that encourage a less active lifestyle, and also encourages faster and cheaper meals. For example, many children now spend more time on their computer or watching TV then playing outdoors. The ""faster and cheaper"" meals are usually less healthy than other meals. Even though many people are living longer, they can choose to live more healthily by adopting regular exercise routines and healthy eating habits. When you choose a sunscreen, select one with an SPF (sun protection factor) of 30 or higher. Also, choose a sunscreen that protects against both UVB and UVA radiation. "
__disease in which the level of glucose in the blood is too high,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,F,"Diabetes is another type of noninfectious disease. Diabetes occurs when the pancreas doesnt make enough insulin or else the bodys cells are resistant to the effects of insulin. Insulin is a hormone that helps cells absorb glucose from the blood. When there is too little insulin or cells do not respond to it, the blood contains too much glucose. High glucose levels in the blood can damage blood vessels and other cells in the body. The kidneys work harder to filter the extra glucose from the blood and excrete it in urine. This leads to frequent urination, which in turn causes excessive thirst. Watch this short video for an animated introduction to diabetes, its causes, and its consequences:  MEDIA Click image to the left or use the URL below. URL:  There are two main types of diabetes: type 1 diabetes and type 2 diabetes. The two types of diabetes have different causes. "
__anything in the environment that may cause cancer,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,B,"Most cancers are caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually occur in genes that control the cell cycle. Because of the mutations, abnormal cells are allowed to divide. Some mutations that lead to cancer may be inherited. However, most of the mutations are caused by environmental factors. Anything in the environment that can cause cancer is called a carcinogen. Common carcinogens include certain chemicals and some types of radiation. Many different chemicals can cause cancer. For example, tobacco contains dozens of chemicals, including nicotine, that have been shown to cause cancer. Figure 21.5 shows some of these chemicals. Smoking tobacco or using smokeless tobacco increases the risk of cancer of the lung, mouth, throat, and urinary bladder. Types of radiation that cause cancer include ultraviolet (UV) radiation and radon. UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a naturally occurring radioactive gas that escapes from underground rocks. It may seep into the basements of buildings. It can cause lung cancer. "
__any substance that may cause an allergy,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,E,"An allergy is a disorder in which the immune system responds to a harmless substance as though it was a pathogen. Any substance that causes an allergy is called an allergen. The most common allergens are pollen, dust mites, mold, animal dander, insect stings, latex, and certain foods and medications. To see in greater detail how allergies occur, watch this animated video:  . MEDIA Click image to the left or use the URL below. URL:  Did you ever hear of hay fever? Its not really a fever, and it may have nothing to do with hay. Its actually an allergy to plant pollens. People with this type of allergy generally have seasonal allergies that come back year after year. Symptoms commonly include watery eyes and nasal congestion. Ragweed, shown blooming in Figure 21.8, causes more pollen allergies than any other plant. Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune systems response. Often, allergy symptoms can be prevented. One way is to avoid exposure to the allergens that cause your symptoms. If you are allergic to pollen, for example, you can reduce your exposure by staying inside when pollen levels are highest. Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens. After many months or years of shots, the immune system gets used to the allergens and no longer reacts to them. "
__disease in which cells divide out of control,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,C,"Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen. Carcinogens may be pathogens, chemicals, or radiation. "
__any disease caused by the immune system attacking the bodys own cells,(A) aautoimmune disease (B) bcarcinogen (C) ccancer (D) dnoninfectious disease (E) eallergen (F) fdiabetes (G) gtumor,A,"Does it make sense for an immune system to attack the cells it is meant to protect? No, but an immune system that does not function properly will attack its own cells. An autoimmune disease is a disease in which the immune system attacks the bodys own cells. One example is type 1 diabetes. In this disease, the immune system attacks cells of the pancreas. Other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain. In rheumatoid arthritis, the immune system attacks the cells of joints. This causes joint damage and pain. Autoimmune diseases cannot be cured. But they can be helped with medicines that weaken the immune systems attack on normal cells. Other autoimmune diseases include celiac disease (damages to the small intestine), inflam- matory bowel disease (damage to the digestive tract), psoriasis (damage to the skin), and lupus (damage to the joints, skin, kidneys, heart, and lungs). "
Causes of noninfectious diseases include,(A) environmental toxins (B) gene mutations (C) pathogens (D) two of the above,D,"Noninfectious diseases cant be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If youre born with these conditions, you must learn how to manage the symptoms. Examples of conditions caused by environmental or lifestyle factors include heart disease and skin cancer. We cant change our genetic codes, but there are plenty of ways to prevent other noninfectious diseases. For example, cutting down on exposure to cigarette smoke and the suns rays will prevent certain types of cancer. It is a fact that most chronic noninfectious diseases can be prevented. The chronic noninfectious diseases that cause the most deaths in many developed countries are largely preventable. These diseases are heart disease, stroke, diabetes and cancer, and though they do have some genetic components, they also have many lifestyle components. For example, some cancers have genetic risks, but people at high risk for cancers can have screening examinations to catch them early or sometimes can take other steps to prevent the cancers. Heart disease, stroke and diabetes are mostly linked to lifestyle choices, even when family history puts a person at higher risk for the diseases. Most allergies can be prevented by avoiding the substances that cause them. For example, you can avoid pollens by staying indoors as much as possible. You can learn to recognize plants like poison ivy and not touch them. A good way to remember how to avoid poison ivy is ""leaves of three, let it be."" Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens, which are the substances that cause an allergic reaction. After many months or years of shots, the immune system gets used to the allergens and no longer responds to them. Type 1 diabetes and other autoimmune diseases cannot be prevented. But choosing a healthy lifestyle can help prevent type 2 diabetes. Getting plenty of exercise, avoiding high-fat foods, and staying at a healthy weight can reduce the risk of developing this type of diabetes. This is especially important for people who have family members with the disease. Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens, which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure 1.1). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesnt matter whether the radiation comes from tanning lamps or the sun. Overall, people in many developed countries are contributing to higher rates of noninfectious diseases (heart disease, stroke, diabetes and cancer) by taking advantage of technology and social environments that encourage a less active lifestyle, and also encourages faster and cheaper meals. For example, many children now spend more time on their computer or watching TV then playing outdoors. The ""faster and cheaper"" meals are usually less healthy than other meals. Even though many people are living longer, they can choose to live more healthily by adopting regular exercise routines and healthy eating habits. When you choose a sunscreen, select one with an SPF (sun protection factor) of 30 or higher. Also, choose a sunscreen that protects against both UVB and UVA radiation. "
Mutations that lead to cancer usually occur in genes that control the,(A) cell cycle (B) production of insulin (C) development of the lungs (D) maturation of the reproductive organs,A,"Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen. Carcinogens may be pathogens, chemicals, or radiation. "
Common carcinogens include,(A) nicotine (B) UV light (C) radon gas (D) all of the above,D,"Many different chemical substances cause cancer. Dozens of chemicals in tobacco smoke, including nicotine, have been shown to cause cancer ( Figure 1.2). In fact, tobacco smoke is one of the main sources of chemical carcinogens. Smoking tobacco increases the risk of cancer of the lung, mouth, throat, and bladder. Using smokeless tobacco can also cause cancer. Other chemicals that cause cancer include asbestos, formaldehyde, benzene, cadmium, and nickel. "
The most common type of cancer in adult males is cancer of the,(A) adrenal gland (B) thyroid gland (C) pituitary gland (D) prostate gland,D,"Cancer occurs most often in adults, especially adults over the age of 50. The most common types of cancer in adults differ between males and females. The most common type of cancer in adult males is cancer of the prostate gland. The prostate gland is part of the male reproductive system. About one third of all cancers in men are prostate cancers. The most common type of cancer in adult females is cancer of the breast. About one third of all cancers in women are breast cancers. In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. Childhood cancer is rare. The main type of cancer in children is leukemia. It makes up about one third of all childhood cancers. It occurs when the body makes abnormal white blood cells. "
The second-most-common type of cancer in adult males and females is cancer of the,(A) stomach (B) liver (C) lung (D) kidney,C,"Cancer occurs most often in adults, especially adults over the age of 50. The most common types of cancer in adults differ between males and females. The most common type of cancer in adult males is cancer of the prostate gland. The prostate gland is part of the male reproductive system. About one third of all cancers in men are prostate cancers. The most common type of cancer in adult females is cancer of the breast. About one third of all cancers in women are breast cancers. In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. Childhood cancer is rare. The main type of cancer in children is leukemia. It makes up about one third of all childhood cancers. It occurs when the body makes abnormal white blood cells. "
All of the following are autoimmune diseases except,(A) type 1 diabetes (B) type 2 diabetes (C) multiple sclerosis (D) rheumatoid arthritis,B,"An autoimmune disease is a disease in which the immune system attacks the bodys own cells. Why this happens is not known for certain, but a combination of genetic and environmental factors are likely to be responsible. Type 1 diabetes is an example of an autoimmune disease. In this case, the immune system attacks cells of the pancreas. Two other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain that gradually get worse over time. In rheumatoid arthritis, the immune system attacks joints. This causes joint damage and pain. These diseases cant be prevented and have no known cure. However, they can be treated with medicines that weaken the immune systems attack on normal cells. "
Allergies are,(A) never life threatening (B) autoimmune diseases (C) commonly caused by pollen (D) two of the above,C,"An allergy is a disorder in which the immune system responds to a harmless substance as though it was a pathogen. Any substance that causes an allergy is called an allergen. The most common allergens are pollen, dust mites, mold, animal dander, insect stings, latex, and certain foods and medications. To see in greater detail how allergies occur, watch this animated video:  . MEDIA Click image to the left or use the URL below. URL:  Did you ever hear of hay fever? Its not really a fever, and it may have nothing to do with hay. Its actually an allergy to plant pollens. People with this type of allergy generally have seasonal allergies that come back year after year. Symptoms commonly include watery eyes and nasal congestion. Ragweed, shown blooming in Figure 21.8, causes more pollen allergies than any other plant. Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune systems response. Often, allergy symptoms can be prevented. One way is to avoid exposure to the allergens that cause your symptoms. If you are allergic to pollen, for example, you can reduce your exposure by staying inside when pollen levels are highest. Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens. After many months or years of shots, the immune system gets used to the allergens and no longer reacts to them. "
All of the following are needed for reproduction in males except the,(A) testes (B) penis (C) epididymis (D) ureters,D,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
__tube that carries sperm from the epididymis to the urethra,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,B,"The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a ""milky"" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive. "
__major male sex hormone,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,G,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
Which of the following structures is part of two different organ systems in males?,(A) vas deferens (B) prostate gland (C) urethra (D) none of the above,C,"The male reproductive organs include the penis, testes, epididymis, vas deferens, and prostate gland. These organs are shown in Figure 22.1. The figure also shows some other parts of the male reproductive system. Find each organ in the drawing as you read about it below. For a cartoon about the male reproductive system, watch this video: http MEDIA Click image to the left or use the URL below. URL:  The penis is an external, cylinder-shaped organ that contains the urethra. The urethra is the tube that carries urine out of the body. It also carries sperm out of the body. The two testes (testis, singular) are oval organs that produce sperm and secrete testosterone. They are located inside a sac called the scrotum that hangs down outside the body. The scrotum also contains the epididymis. "
Which statement about sperm is false?,(A) Sperm are produced in the testes (B) Maturation of sperm takes place in the vas deferens (C) It takes up to 2 months for sperm to form and mature (D) Sperm are stored in the epididymis until they leave the body,B,"As you can see in Figure 22.2, a sperm has three main parts: the head, connecting piece (or midpiece), and tail. 1. The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. 2. The connecting piece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy to move. 3. The tail of the sperm moves like a propeller. It spins around and around and pushes the sperm forward. Sperm can travel about 30 inches per hour. "
__whitish fluid that contains sperm,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,F,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
__male sex cell,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,D,"Sperm ( Figure 1.1), the male reproductive cells, are tiny. In fact, they are the smallest cells in the human body. What do you think a sperm cell looks like? Some people think that it looks like a tadpole. Do you agree? "
The nucleus of a human sperm cell,(A) is located in the connecting piece (B) contains 23 chromosomes (C) is packed with mitochondria (D) lacks a nuclear membrane,B,"As you can see in Figure 22.2, a sperm has three main parts: the head, connecting piece (or midpiece), and tail. 1. The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. 2. The connecting piece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy to move. 3. The tail of the sperm moves like a propeller. It spins around and around and pushes the sperm forward. Sperm can travel about 30 inches per hour. "
__coiled tube where sperm mature,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,E,"The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a ""milky"" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive. "
A spermatid is a(n),(A) immature sperm cell (B) diploid sex cell in a male (C) cell that will divide to form a sperm (D) sperm cell after it leaves the epididymis,A,"Sperm ( Figure 1.1), the male reproductive cells, are tiny. In fact, they are the smallest cells in the human body. What do you think a sperm cell looks like? Some people think that it looks like a tadpole. Do you agree? "
__male organ that contains the urethra,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,A,"The male reproductive organs include the penis, testes, epididymis, vas deferens, and prostate gland. These organs are shown in Figure 22.1. The figure also shows some other parts of the male reproductive system. Find each organ in the drawing as you read about it below. For a cartoon about the male reproductive system, watch this video: http MEDIA Click image to the left or use the URL below. URL:  The penis is an external, cylinder-shaped organ that contains the urethra. The urethra is the tube that carries urine out of the body. It also carries sperm out of the body. The two testes (testis, singular) are oval organs that produce sperm and secrete testosterone. They are located inside a sac called the scrotum that hangs down outside the body. The scrotum also contains the epididymis. "
__structure that secretes a fluid that helps form semen,(A) apenis (B) bvas deferens (C) cprostate gland (D) dsperm (E) eepididymis (F) fsemen (G) gtestosterone,C,"The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a ""milky"" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive. "
Sperm mix with secretions as they pass through the vas deferens.,(A) true (B) false,A,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
An adult male normally produces about 100 sperm each day.,(A) true (B) false,B,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
Testosterone is needed for the production of sperm.,(A) true (B) false,A,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
Sperm are the smallest of all human cells.,(A) true (B) false,A,"Sperm are tiny cells. In fact, they are the smallest of all human cells. They have a structure that suits them well to perform their function. "
Sperm swim at a speed of about 3 inches per hour.,(A) true (B) false,B,"As you can see in Figure 22.2, a sperm has three main parts: the head, connecting piece (or midpiece), and tail. 1. The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. 2. The connecting piece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy to move. 3. The tail of the sperm moves like a propeller. It spins around and around and pushes the sperm forward. Sperm can travel about 30 inches per hour. "
What are roles of testosterone in males?,(A) causing the sex organs to mature at puberty (B) stimulating the production of sperm by the testes (C) causing facial hair to start growing in teens (D) all of the above,D,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
Which of the following statements about sperm is false?,(A) Sperm are gametes (B) Sperm are diploid cells (C) The only role of sperm is reproduction (D) Only mature sperm have a tail,B,"As you can see in Figure 22.2, a sperm has three main parts: the head, connecting piece (or midpiece), and tail. 1. The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. 2. The connecting piece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy to move. 3. The tail of the sperm moves like a propeller. It spins around and around and pushes the sperm forward. Sperm can travel about 30 inches per hour. "
How many sperm does the average adult male produce each day?,(A) about ten (B) several dozen (C) a few hundred (D) millions,D,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
Sperm cells leave the body through the,(A) ureter (B) vas deferens (C) epididymis (D) urethra,D,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
The scrotum contains the,(A) testes (B) epididymis (C) prostate gland (D) two of the above,D,"The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a ""milky"" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive. "
The acrosome of a sperm,(A) is at the end of the tail (B) contains enzymes (C) makes the tail move (D) two of the above,B,"As you can see in Figure 22.2, a sperm has three main parts: the head, connecting piece (or midpiece), and tail. 1. The head of the sperm contains the nucleus. The nucleus holds the chromosomes. In humans, the nucleus of a sperm cell contains 23 chromosomes. The acrosome on the head contains enzymes that help the sperm penetrate an egg. 2. The connecting piece of the sperm is packed with mitochondria. Mitochondria are organelles in cells that produce energy. Sperm use the energy to move. 3. The tail of the sperm moves like a propeller. It spins around and around and pushes the sperm forward. Sperm can travel about 30 inches per hour. "
"For sperm to form and mature, it takes up to two",(A) days (B) weeks (C) months (D) years,C,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
The reproductive system is the only human body system that differs significantly between males and,(A) true (B) false,A,Other reproductive system disorders include injuries and noninfectious diseases. These are different in males and females. 
Both mitosis and meiosis are involved in the production of sperm.,(A) true (B) false,A,"Mitosis, meiosis, and sexual reproduction are discussed at  . Click image to the left or use the URL below. URL:  Both mitosis and meiosis result in eukaryotic cells dividing. So what is the difference between mitosis and meiosis? The primary difference is the differing goals of each process. The goal of mitosis is to produce two daughter cells that are genetically identical to the parent cell, meaning the new cells have exactly the same DNA as the parent cell. Mitosis happens when you want to grow, for example. You want all your new cells to have the same DNA as the previous cells. The goal of meiosis, however, is to produce sperm or eggs, also known as gametes. The resulting gametes are not genetically identical to the parent cell. Gametes are haploid cells, with only half the DNA present in the diploid parent cell. This is necessary so that when a sperm and an egg combine at fertilization, the resulting zygote has the correct amount of DNAnot twice as much as the parents. The zygote then begins to divide through mitosis. Pictured below is a comparison between binary fission (Figure 1.1), which is cell division of prokaryotic organisms, mitosis, and meiosis. Mitosis and meiosis are also compared in the table that follows (Table 1.1). A comparison between binary fission, mi- tosis, and meiosis. Purpose Number of Cells Produced Rounds of Cell Division Haploid or Diploid Daughter cells identical to parent cells? Daughter cells identical to each other? Mitosis To produce new cells 2 1 Diploid Yes Meiosis To produce gametes 4 2 Haploid No Yes No "
Testosterone causes the voice to deepen when a male goes through puberty.,(A) true (B) false,A,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
The only external male reproductive organ is the penis.,(A) true (B) false,B,"The male reproductive organs include the penis, testes, epididymis, vas deferens, and prostate gland. These organs are shown in Figure 22.1. The figure also shows some other parts of the male reproductive system. Find each organ in the drawing as you read about it below. For a cartoon about the male reproductive system, watch this video: http MEDIA Click image to the left or use the URL below. URL:  The penis is an external, cylinder-shaped organ that contains the urethra. The urethra is the tube that carries urine out of the body. It also carries sperm out of the body. The two testes (testis, singular) are oval organs that produce sperm and secrete testosterone. They are located inside a sac called the scrotum that hangs down outside the body. The scrotum also contains the epididymis. "
Testosterone is a hormone secreted by the prostate gland.,(A) true (B) false,B,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
Sperm are stored in the vas deferens until they leave the body.,(A) true (B) false,B,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
A teaspoon of semen may contain as many as half a billion sperm.,(A) true (B) false,A,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
Fertilization of an egg normally takes place while the egg is in the,(A) vagina (B) uterus (C) cervix (D) fallopian tube,D,"Egg production takes place in the ovaries. It occurs in several steps: 1. Before birth, special cells in the ovaries go through mitosis to make identical daughter cells. 2. The daughter cells then start to divide by meiosis. However, they go though only the first of the two cell divisions of meiosis at this time. They remain in that stage until the girl goes through puberty. 3. After puberty, an egg develops in an ovary about once a month. As you can see in Figure 22.4, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. 4. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation. After ovulation occurs, the moving fingers of the nearby fallopian tube sweep the egg into the tube. Fertilization may occur if sperm reach the egg while it is passing through the fallopian tube. If this happens, the egg finally completes meiosis. This results in two daughter cells that differ in size. The smaller cell is called a polar body. It soon breaks down and disappears. The larger cell is the fertilized egg, which will develop into a new human being. "
__structure where fertilization of an egg normally occurs,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,F,"Egg production takes place in the ovaries. It occurs in several steps: 1. Before birth, special cells in the ovaries go through mitosis to make identical daughter cells. 2. The daughter cells then start to divide by meiosis. However, they go though only the first of the two cell divisions of meiosis at this time. They remain in that stage until the girl goes through puberty. 3. After puberty, an egg develops in an ovary about once a month. As you can see in Figure 22.4, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. 4. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation. After ovulation occurs, the moving fingers of the nearby fallopian tube sweep the egg into the tube. Fertilization may occur if sperm reach the egg while it is passing through the fallopian tube. If this happens, the egg finally completes meiosis. This results in two daughter cells that differ in size. The smaller cell is called a polar body. It soon breaks down and disappears. The larger cell is the fertilized egg, which will develop into a new human being. "
__cylinder-shaped organ through which a baby passes during birth,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,D,"During childbirth, a baby passes from the uterus, through the vagina, and out of the mothers body. Childbirth usually starts when the amniotic sac breaks. Then, the muscles of the uterus start contracting. The contractions get stronger and closer together. They may go on for hours. Eventually, the contractions squeeze the baby out of the uterus. Once the baby enters the vagina, the mother starts pushing. She soon pushes the baby through the vagina and out of her body. As soon as the baby is born, the umbilical cord is cut. After the cord is cut, the baby can no longer get rid of carbon dioxide through the cord and placenta. As a result, carbon dioxide builds up in the babys blood. This triggers the baby to start breathing. The amniotic sac and placenta pass through the vagina and out of the body shortly after the birth of the baby. "
Which statement about human eggs is false?,(A) Eggs are haploid gametes (B) Eggs are the largest human cells (C) There are billions of eggs in each ovary at birth (D) none of the above,C,"Human eggs are very large cells. In fact, they are the largest of all human cells. You can even see an egg without a microscope. Its almost as big as the period at the end of this sentence. Like a sperm cell, an egg cell is a haploid cell with half the number of chromosomes of other cells in the body. Unlike a sperm cell, the egg lacks a tail and contains a lot of cytoplasm. "
Which statement about the human uterus is false?,(A) It is a hollow organ (B) It has thick (C) muscular walls (D) c It has just one opening (E) called the cervix (F) d It can stretch to accommodate a growing baby,C,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
__one of a pair of organs that produce and release eggs,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,G,"Most of the male reproductive organs are outside of the body. But female reproductive organs are inside of the body. The male and female organs also look very different and have different jobs. Two of the functions of the female reproductive system are similar to the functions of the male reproductive system. The female system: 1. Produces gametes, the reproductive cells, which are called eggs in females. 2. Secretes a major sex hormone, estrogen. One of the main roles of the female reproductive system is to produce eggs. Eggs ( Figure 1.1) are female gametes, and they are made in the ovaries. After puberty, females release only one egg at a time. Eggs are actually made in the body before birth, but they do not fully develop until later in life. Like sperm, eggs are produced by meiosis, so they contain half the number of chromosomes as the original cell. Another role of the female system is to secrete estrogen. Estrogen is the main sex hormone in females. Estrogen has two major roles: 1. During the teen years, estrogen causes the reproductive organs to develop. It also causes other female traits to develop. For example, it causes the breasts to grow. 2. During adulthood, estrogen is needed for a woman to release eggs. On average, a woman releases one egg each month from her ovaries. The female reproductive system has another important function. After puberty, the female reproductive system must prepare itself to accept a fertilized egg each cycle (about every month). This cycle is controlled by a well-planned and very complex interplay of hormones. If an egg is not fertilized, the system must prepare itself again the next cycle. The female reproductive system also supports a baby as it develops before birth, and it facilitates the babys birth at the end of pregnancy. "
__organ where a fetus develops and grows until birth,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,B,"From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure 22.7. By the 38th week, the fetus is fully developed and ready to be born. A 38-week fetus normally ranges from about 36 to 51 centimeters (1420 inches) in length and weighs between 2.7 and 4.6 kilograms (about 610 pounds). "
Which of the following organs opens directly to the surface of the body?,(A) ovary (B) fallopian tube (C) vagina (D) uterus,C,"Did you know that you see the largest organ in your body every day? You wash it, dry it, cover it up to stay warm, and uncover it to cool off. Yes, your skin is your bodys largest organ. Your skin is part of your integumentary system ( Figure 1.1), which is the outer covering of your body. The integumentary system is made up of your skin, hair, and nails. Skin acts as a barrier that stops water and other things, like soap and dirt, from getting into your body. "
__female gamete,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,E,Sexual reproduction is more complicated. It involves two parents. Special cells called gametes are produced by the parents. A gamete produced by a female parent is generally called an egg. A gamete produced by a male parent is usually called a sperm. An offspring forms when two gametes unite. The union of the two gametes is called fertilization. You can see a human sperm and egg uniting in Figure 5.12. The initial cell that forms when two gametes unite is called a zygote. 
The structure in which an egg develops inside an ovary is called a,(A) fimbria (B) follicle (C) fallopian tube (D) none of the above,B,"Egg production takes place in the ovaries. It takes several steps to make an egg: 1. Before birth, special cells in the ovaries go through mitosis (cell division), producing identical cells. 2. The daughter cells then start to divide by meiosis. But they only go through the first of the two cell divisions of meiosis at that time. They go through the second stage of cell division after the female goes through puberty. 3. In a mature female, an egg develops in an ovary about once a month. The drawing below shows how this happens ( Figure 1.1). As you can see from the figure, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. The follicle protects the egg as it matures in the ovary. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation, which usually occurs at the midpoint of a monthly cycle. In a 28 day cycle, ovulation would occur around day 14. The moving fingers of the nearby fallopian tube then sweep the egg into the tube. At this time, if sperm are present the egg can be fertilized. Fertilization occurs if a sperm enters the egg while it is passing through the fallopian tube. When this happens, the egg finally completes meiosis. This results in two daughter cells that are different in size. The smaller cell is called a polar body. It contains very little cytoplasm. It soon breaks down and disappears. The larger cell is the egg. It contains most of the cytoplasm. This will develop into a child. "
__small opening that connects the uterus to the vagina,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,C,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
__main female sex hormone,(A) aestrogen (B) buterus (C) ccervix (D) dvagina (E) eegg (F) ffallopian tube (G) govary,A,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
Estrogen causes the changes of puberty in females.,(A) true (B) false,A,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
"Following puberty, an egg is released by each ovary about once a week.",(A) true (B) false,B,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after she starts having menstrual periods at about age 12 or 13. Just one egg develops each month. A woman will release an egg once each month until she is in her 40s. A girl is born with over a million eggs. They die off and by puberty about 40,000 remain. "
Estrogen is secreted by female gonads.,(A) true (B) false,A,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
"To fertilize an egg, sperm must swim from the vagina to an ovary.",(A) true (B) false,B,"Egg production takes place in the ovaries. It occurs in several steps: 1. Before birth, special cells in the ovaries go through mitosis to make identical daughter cells. 2. The daughter cells then start to divide by meiosis. However, they go though only the first of the two cell divisions of meiosis at this time. They remain in that stage until the girl goes through puberty. 3. After puberty, an egg develops in an ovary about once a month. As you can see in Figure 22.4, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. 4. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation. After ovulation occurs, the moving fingers of the nearby fallopian tube sweep the egg into the tube. Fertilization may occur if sperm reach the egg while it is passing through the fallopian tube. If this happens, the egg finally completes meiosis. This results in two daughter cells that differ in size. The smaller cell is called a polar body. It soon breaks down and disappears. The larger cell is the fertilized egg, which will develop into a new human being. "
The menstrual cycle is also called a menstrual period.,(A) true (B) false,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
The main female reproductive organs are inside the body.,(A) true (B) false,A,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
The male and female reproductive systems have identical functions.,(A) true (B) false,B,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
Estrogen is needed for an adult woman to release eggs from the ovaries.,(A) true (B) false,A,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after the female reaches puberty at about age 12 or 13. Then, just one egg develops each month until she reaches her 40s or early 50s. "
The ovaries make eggs only after a female has gone through puberty.,(A) true (B) false,B,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after the female reaches puberty at about age 12 or 13. Then, just one egg develops each month until she reaches her 40s or early 50s. "
The upper end of each fallopian tube is attached to an ovary.,(A) true (B) false,B,"The female reproductive organs include the ovaries, fallopian tubes, uterus, and vagina. These organs are shown in Figure 22.3, along with some other structures of the female reproductive system. Find each organ in the drawing as you read about it below. For a cartoon about the female reproductive system, watch this video: http://education-por The two ovaries are small, oval organs on either side of the abdomen. Each ovary contains thousands of eggs. However, the eggs do not develop fully until a female has gone through puberty. Then, about once a month, an egg is released by one of the ovaries. The ovaries also secrete estrogen. The two fallopian tubes are thin tubes that are connected to the uterus and extend almost to the ovaries. The upper end of each fallopian tube has fingers (called fimbriae) that sweep an egg into the fallopian tube when it is released by the ovary. The egg then passes through the fallopian tube to the uterus. If an egg is fertilized, this occurs in the fallopian tube. The uterus is a hollow organ with muscular walls. The uterus is where a baby develops until birth. The walls of the uterus stretch to accommodate the growing fetus. The muscles in the walls contract to push the baby out during birth. The uterus is connected to the vagina by a small opening called the cervix. The vagina is a cylinder-shaped organ that opens to the outside of the body. The other end joins with the uterus. Sperm deposited in the vagina swim up through the cervix, into the uterus, and from there into a "
An egg completes meiosis just before it leaves the ovary.,(A) true (B) false,B,"Egg production takes place in the ovaries. It takes several steps to make an egg: 1. Before birth, special cells in the ovaries go through mitosis (cell division), producing identical cells. 2. The daughter cells then start to divide by meiosis. But they only go through the first of the two cell divisions of meiosis at that time. They go through the second stage of cell division after the female goes through puberty. 3. In a mature female, an egg develops in an ovary about once a month. The drawing below shows how this happens ( Figure 1.1). As you can see from the figure, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. The follicle protects the egg as it matures in the ovary. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation, which usually occurs at the midpoint of a monthly cycle. In a 28 day cycle, ovulation would occur around day 14. The moving fingers of the nearby fallopian tube then sweep the egg into the tube. At this time, if sperm are present the egg can be fertilized. Fertilization occurs if a sperm enters the egg while it is passing through the fallopian tube. When this happens, the egg finally completes meiosis. This results in two daughter cells that are different in size. The smaller cell is called a polar body. It contains very little cytoplasm. It soon breaks down and disappears. The larger cell is the egg. It contains most of the cytoplasm. This will develop into a child. "
"While an egg is developing in a follicle, the lining of the uterus breaks down and passes out of the",(A) true (B) false,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
"When a girl is born, how many eggs does each of her ovaries normally contain?",(A) none (B) a few (C) about a hundred (D) thousands,D,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after she starts having menstrual periods at about age 12 or 13. Just one egg develops each month. A woman will release an egg once each month until she is in her 40s. A girl is born with over a million eggs. They die off and by puberty about 40,000 remain. "
Which female reproductive structure secretes estrogen?,(A) uterus (B) vagina (C) ovary (D) cervix,C,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
An egg reaches the uterus through,(A) a fallopian tube (B) the vagina (C) the cervix (D) none of the above,A,"Egg production takes place in the ovaries. It occurs in several steps: 1. Before birth, special cells in the ovaries go through mitosis to make identical daughter cells. 2. The daughter cells then start to divide by meiosis. However, they go though only the first of the two cell divisions of meiosis at this time. They remain in that stage until the girl goes through puberty. 3. After puberty, an egg develops in an ovary about once a month. As you can see in Figure 22.4, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. 4. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation. After ovulation occurs, the moving fingers of the nearby fallopian tube sweep the egg into the tube. Fertilization may occur if sperm reach the egg while it is passing through the fallopian tube. If this happens, the egg finally completes meiosis. This results in two daughter cells that differ in size. The smaller cell is called a polar body. It soon breaks down and disappears. The larger cell is the fertilized egg, which will develop into a new human being. "
The walls of the uterus,(A) can stretch (B) are muscular (C) push out a baby during birth (D) all of the above,D,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
"For fertilization to take place, sperm generally must be deposited in the",(A) ovary (B) fimbria (C) uterus (D) vagina,D,"Fish reproduce sexually. They lay eggs that can be fertilized either inside or outside of the body. In most fish, the eggs develop outside of the mothers body. In the majority of these species, fertilization also takes place outside the mothers body. The male and female fish release their gametes into the surrounding water, where fertilization occurs. Female fish release very high numbers of eggs to increase the chances of fertilization. "
A human egg cell,(A) contains very little cytoplasm (B) is a diploid cell (C) lacks a tail (D) two of the above,C,"Human eggs are very large cells. In fact, they are the largest of all human cells. You can even see an egg without a microscope. Its almost as big as the period at the end of this sentence. Like a sperm cell, an egg cell is a haploid cell with half the number of chromosomes of other cells in the body. Unlike a sperm cell, the egg lacks a tail and contains a lot of cytoplasm. "
The changes of the menstrual cycle take place in the,(A) ovaries (B) uterus (C) labium (D) two of the above,D,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
The layer of a blastocyst that develops into the placenta is the,(A) embryoblast (B) blastoblast (C) trophoblast (D) photoblast,C,"The zygote spends the next few days traveling down the fallopian tube toward the uterus, where it will take up residence. As it travels, it divides many times by mitosis. It soon forms a tiny, fluid-filled ball of cells called a blastocyst. The blastocyst has an inner and outer layer of cells, as you can see in Figure 22.5. The inner layer, called the embryoblast, will develop into the new human being. The outer layer, called the trophoblast, will develop into other structures needed to support the new organism. "
What happens when a sperm penetrates the cell membrane of an egg?,(A) The egg completes meiosis (B) The sperms tail falls off (C) The nuclei of sperm and egg fuse (D) all of the above,D,"When a sperm penetrates the cell membrane of an egg, it triggers the egg to complete meiosis. The sperm also undergoes changes. Its tail falls off, and its nucleus fuses with the nucleus of the egg. The resulting cell, called a zygote, contains the diploid number of chromosomes. Half of the chromosomes come from the egg, and half come from the sperm. You can watch the process of fertilization and the development of a baby until birth in this amazing video:  MEDIA Click image to the left or use the URL below. URL: "
"After fertilization occurs, how long does it normally take for the blastocyst to reach the uterus and implant in the uterine lining?",(A) about an hour (B) about a day (C) about a week (D) about a month,C,"The blastocyst continues down the fallopian tube until it reaches the uterus, about 4 or 5 days after fertilization. When the outer cells of the blastocyst contact cells lining the uterus (the endometrium in Figure 22.5), the blastocyst embeds itself in the uterine lining. This process is called implantation. It generally occurs about a week after fertilization. "
"By the end of the embryonic stage, the embryo is about",(A) 1 inch long (B) 6 inches long (C) 1 foot long (D) 15 feet long,A,"After implantation occurs, the blastocyst is called an embryo. The embryonic stage lasts from the end of the first week following fertilization through the end of the eighth week. During this time, the embryo grows in size and becomes more complex. It develops specialized cells and tissues. Most organs also start to form. You can see some of the specific changes that take place during weeks four to eight of the embryonic period in Figure 22.6. By the end of week eight, the embryo is about 30 millimeters (just over 1 inch) in length. It may also have begun to move. "
During which stage of development do most organs start to form?,(A) blastocyst (B) embryo (C) fetus (D) infancy,B,"During the embryo stage, the baby grows in size. 3rd week after fertilization: Cells of different types start to develop. Cells that will form muscles and skin, for example, start to develop at this time. 4th week after fertilization: Body organs begin to form. 8th week after fertilization: All the major organs have started to develop. Pictured below are some of the changes that take place during the 4th and 8th weeks ( Figure 1.1). Look closely at the two embryos in the figure. Do you think that the older embryo looks more human? Notice that it has arms and legs and lacks a tail. The face has also started to form, and it is much bigger. Embryonic Development (Weeks 48). Most organs develop in the embryo during weeks four through eight. (Note: the drawings of the embryos are not to scale.) "
Which of these events occurs during the embryonic stage?,(A) The eyelids form (B) The heart begins to beat (C) Tooth buds appear (D) all of the above,B,"After implantation occurs, the blastocyst is called an embryo. The embryonic stage lasts from the end of the first week following fertilization through the end of the eighth week. During this time, the embryo grows in size and becomes more complex. It develops specialized cells and tissues. Most organs also start to form. You can see some of the specific changes that take place during weeks four to eight of the embryonic period in Figure 22.6. By the end of week eight, the embryo is about 30 millimeters (just over 1 inch) in length. It may also have begun to move. "
Which of the following changes does not occur during the fetal stage?,(A) The blood starts to circulate (B) The brain becomes active (C) Alveoli form in the lungs (D) Muscles develop,A,"There are also many changes that take place after the embryo becomes a fetus. Some of the differences between them are obvious. For example, the fetus has ears and eyelids. Its fingers and toes are also fully formed. The fetus even has fingernails and toenails. In addition, the reproductive organs have developed to make the baby a male or female. The brain and lungs are also developing quickly. The fetus has started to move around inside the uterus. This is usually when the mother first feels the fetus moving. By the 28th week, the fetus is starting to look much more like a baby. Eyelashes and eyebrows are present. Hair has started to grow on the head. The body of the fetus is also starting to fill out as muscles and bones develop. Babies born after the 28th week are usually able to survive. However, they need help breathing because their lungs are not yet fully mature. A baby should not be delivered prior to this time, unless absolutely necessary. A baby born prior to week 28 will need considerable medical intervention to survive. During the last several weeks of the fetal period, all of the organs become mature. The most obvious change, however, is an increase in body size. The fetus rapidly puts on body fat and gains weight during the last couple of months. By the end of the 38th week, all of the organs are working, and the fetus is ready to be born. This is when birth normally occurs. A baby born before this time is considered premature. "
About how much does a 38-week fetus weigh?,(A) 12 pounds (B) 35 pounds (C) 610 pounds (D) 1116 pounds,C,"From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure 22.7. By the 38th week, the fetus is fully developed and ready to be born. A 38-week fetus normally ranges from about 36 to 51 centimeters (1420 inches) in length and weighs between 2.7 and 4.6 kilograms (about 610 pounds). "
At about how many weeks after fertilization does birth typically occur?,(A) 16 (B) 24 (C) 32 (D) 38,D,"From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure 22.7. By the 38th week, the fetus is fully developed and ready to be born. A 38-week fetus normally ranges from about 36 to 51 centimeters (1420 inches) in length and weighs between 2.7 and 4.6 kilograms (about 610 pounds). "
The placenta allows the maternal and fetal blood to,(A) mix together (B) come close together (C) exchange substances (D) two of the above,D,"The fetus could not grow and develop without oxygen and nutrients from the mother. Wastes from the fetus also must be removed in order for it to survive. The exchange of these substances between the mother and fetus occurs through the placenta. The placenta is a temporary organ that starts to form shortly after implantation. It forms from the trophoblast layer of cells in the blastocyst and from maternal cells in the uterus. The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure 22.8, is made up of a large mass of blood vessels from both mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mothers and fetuss blood to exchange substances across their capillary walls without the blood actually mixing. The fetus is connected to the placenta through the umbilical cord. This is a long tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries. It exchanges gases and other substances with the mothers blood. Then it travels back to the fetus through the umbilical vein. Another structure that supports the fetus is the amniotic sac. This is a membrane that surrounds and protects the fetus. It contains amniotic fluid, which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. "
"During infancy, which of these developments generally occurs first ?",(A) sitting (B) babbling (C) crawling (D) smiling,D,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
During which of the following life stages is growth in height and weight usually most rapid?,(A) infancy (B) early childhood (C) middle childhood (D) late childhood,A,"Early adulthood refers to the 20s and early 30s. During early adulthood, most people are at their physical peak, and they are usually in good health. Often, they are completing their education and getting established in the workforce. Many people become engaged or marry during this time. "
A babys first teeth start coming in at about 12 months of age.,(A) true (B) false,B,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
Toddlers grow more rapidly than infants.,(A) true (B) false,B,"The first year after birth is called infancy. Infancy is a period when the baby grows very fast. During infancy, the baby doubles in length and triples in weight. Other important changes also happen during infancy: The babys teeth start to come in, usually at about six months of age ( Figure 1.1). The baby starts smiling, paying attention to other people, and grabbing toys. The baby begins making babbling sounds. By the end of the first year, the baby is starting to say a few words, such as mama and dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. Childhood begins after the babys first birthday and continues until the teen years. Between one and three years of age, a child is called a toddler. During the toddler stage, growth is still fast, but not as fast as it was during infancy. A toddler learns many new words. The child even starts putting together words in simple sentences. Motor skills also develop quickly during this stage. By age three, most children can run and climb steps. They can hold crayons and scribble with them. They can also feed themselves and use the toilet. From age three until the teens, growth is slower. The body also changes shape. The arms and legs get longer compared to the trunk. Children continue to develop new motor skills. For example, many young children learn how to ride a tricycle and then a bicycle. Most also learn how to play games and sports ( Figure 1.2). By age six, children start losing their baby teeth. Their permanent teeth begin coming in to replace them. They also start school and learn how to read and write. They develop friendships and become less dependent on their parents. "
Puberty occurs at the same age in all children.,(A) true (B) false,B,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
A boys voice deepens at puberty as his larynx grows bigger.,(A) true (B) false,A,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
People generally start showing signs of aging in middle adulthood.,(A) true (B) false,A,"Middle adulthood begins in the mid-30s. It continues until the mid-60s. During middle adulthood, people start to show signs of aging. Their hair slowly turns gray. Their skin develops wrinkles. The risk of health problems also increases during middle adulthood. For example, heart disease, cancer, and diabetes become more common during this time. This is the stage of life when people are most likely to achieve career goals. Their children also grow up and may leave home during this stage. "
A zygote has the haploid number of chromosomes.,(A) true (B) false,B,"A cell with two sets of chromosomes is diploid, referred to as 2n, where n is the number of sets of chromosomes. Most of the cells in a human body are diploid. A cell with one set of chromosomes, such as a gamete, is haploid, referred to as n. Sex cells are haploid. When a haploid sperm (n) and a haploid egg (n) combine, a diploid zygote will be formed (2n). In short, when a diploid zygote is formed, half of the DNA comes from each parent. "
"As soon as a zygote starts to divide, it is called an embryo.",(A) true (B) false,B,"The zygote spends the next few days traveling down the fallopian tube toward the uterus, where it will take up residence. As it travels, it divides many times by mitosis. It soon forms a tiny, fluid-filled ball of cells called a blastocyst. The blastocyst has an inner and outer layer of cells, as you can see in Figure 22.5. The inner layer, called the embryoblast, will develop into the new human being. The outer layer, called the trophoblast, will develop into other structures needed to support the new organism. "
Most organs start to form during the embryonic stage.,(A) true (B) false,A,"During the embryo stage, the baby grows in size. 3rd week after fertilization: Cells of different types start to develop. Cells that will form muscles and skin, for example, start to develop at this time. 4th week after fertilization: Body organs begin to form. 8th week after fertilization: All the major organs have started to develop. Pictured below are some of the changes that take place during the 4th and 8th weeks ( Figure 1.1). Look closely at the two embryos in the figure. Do you think that the older embryo looks more human? Notice that it has arms and legs and lacks a tail. The face has also started to form, and it is much bigger. Embryonic Development (Weeks 48). Most organs develop in the embryo during weeks four through eight. (Note: the drawings of the embryos are not to scale.) "
The fetal period typically lasts about 30 weeks.,(A) true (B) false,A,"From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure 22.7. By the 38th week, the fetus is fully developed and ready to be born. A 38-week fetus normally ranges from about 36 to 51 centimeters (1420 inches) in length and weighs between 2.7 and 4.6 kilograms (about 610 pounds). "
The purpose of the placenta is to cushion the fetus and protect it from injury.,(A) true (B) false,B,"During pregnancy, other structures also develop inside the mothers uterus. They are the amniotic sac, placenta, and umbilical cord ( Figure 1.2). Surrounding the fetus is the fluid-filled amniotic sac. The placenta and umbilical cord are also shown here. They provide a connection between the mothers and fetuss blood for the transfer of nutrients and gases. The amniotic sac is a membrane that surrounds the fetus. It is filled with water and dissolved substances, known as amniotic fluid. Imagine placing a small plastic toy inside a balloon and then filling the balloon with water. The toy would be cushioned and protected by the water. It would also be able to move freely inside the balloon. The amniotic sac and its fluid are like a water-filled balloon. They cushion and protect the fetus. They also let the fetus move freely inside the uterus. The placenta is a spongy mass of blood vessels. Some of the vessels come from the mother. Some come from the fetus. The placenta is attached to the inside of the mothers uterus. The fetus is connected to the placenta by a tube called the umbilical cord. The cord contains two arteries and a vein. Substances pass back and forth between the mothers and fetuss blood through the placenta and cord. Oxygen and nutrients pass from the mother to the fetus. Carbon dioxide passes from the fetus to the mother. It is important for the mother to eat plenty of nutritious foods during pregnancy. She must take in enough nutrients for the fetus as well as for herself. She needs extra calories, proteins, and lipids. She also needs more vitamins and minerals. In addition to eating well, the mother must avoid substances that could harm the embryo or fetus. These include alcohol, illegal drugs, and some medicines. It is especially important for her to avoid these substances during the first eight weeks after fertilization. This is when all the major organs are forming. Exposure to harmful substances during this time could damage the developing body systems. "
The umbilical cord is cut only after the baby starts to breathe on its own.,(A) true (B) false,B,"Near the time of birth, the amniotic sac breaks in a gush of liquid. Labor usually begins within a day of this event. Labor involves contractions of the muscular walls of the uterus. With the mothers help, the contractions eventually push the fetus out of the uterus and through the vagina. Within seconds of birth, the umbilical cord is cut. Without this connection to the placenta, the baby cant exchange gases, so carbon dioxide quickly builds up in the babys blood. This stimulates the babys brain to trigger breathing, and the newborn takes her first breath. "
Puberty generally occurs at an earlier age in girls than in boys.,(A) true (B) false,A,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
__process in which a blastocyst embeds in the uterine lining,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,F,"The blastocyst continues down the fallopian tube until it reaches the uterus, about 4 or 5 days after fertilization. When the outer cells of the blastocyst contact cells lining the uterus (the endometrium in Figure 22.5), the blastocyst embeds itself in the uterine lining. This process is called implantation. It generally occurs about a week after fertilization. "
__fluid-filled membrane that surrounds and protects a fetus,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,C,"During pregnancy, other structures also develop inside the mothers uterus. They are the amniotic sac, placenta, and umbilical cord ( Figure 1.2). Surrounding the fetus is the fluid-filled amniotic sac. The placenta and umbilical cord are also shown here. They provide a connection between the mothers and fetuss blood for the transfer of nutrients and gases. The amniotic sac is a membrane that surrounds the fetus. It is filled with water and dissolved substances, known as amniotic fluid. Imagine placing a small plastic toy inside a balloon and then filling the balloon with water. The toy would be cushioned and protected by the water. It would also be able to move freely inside the balloon. The amniotic sac and its fluid are like a water-filled balloon. They cushion and protect the fetus. They also let the fetus move freely inside the uterus. The placenta is a spongy mass of blood vessels. Some of the vessels come from the mother. Some come from the fetus. The placenta is attached to the inside of the mothers uterus. The fetus is connected to the placenta by a tube called the umbilical cord. The cord contains two arteries and a vein. Substances pass back and forth between the mothers and fetuss blood through the placenta and cord. Oxygen and nutrients pass from the mother to the fetus. Carbon dioxide passes from the fetus to the mother. It is important for the mother to eat plenty of nutritious foods during pregnancy. She must take in enough nutrients for the fetus as well as for herself. She needs extra calories, proteins, and lipids. She also needs more vitamins and minerals. In addition to eating well, the mother must avoid substances that could harm the embryo or fetus. These include alcohol, illegal drugs, and some medicines. It is especially important for her to avoid these substances during the first eight weeks after fertilization. This is when all the major organs are forming. Exposure to harmful substances during this time could damage the developing body systems. "
__fluid-filled ball of cells that forms soon after fertilization occurs,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,B,"The zygote spends the next few days traveling down the fallopian tube toward the uterus, where it will take up residence. As it travels, it divides many times by mitosis. It soon forms a tiny, fluid-filled ball of cells called a blastocyst. The blastocyst has an inner and outer layer of cells, as you can see in Figure 22.5. The inner layer, called the embryoblast, will develop into the new human being. The outer layer, called the trophoblast, will develop into other structures needed to support the new organism. "
__cell layer in the blastocyst that will develop into the placenta,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,E,"The zygote spends the next few days traveling down the fallopian tube toward the uterus, where it will take up residence. As it travels, it divides many times by mitosis. It soon forms a tiny, fluid-filled ball of cells called a blastocyst. The blastocyst has an inner and outer layer of cells, as you can see in Figure 22.5. The inner layer, called the embryoblast, will develop into the new human being. The outer layer, called the trophoblast, will develop into other structures needed to support the new organism. "
__tube containing blood vessels that connects a fetus to the placenta,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,G,"The fetus could not grow and develop without oxygen and nutrients from the mother. Wastes from the fetus also must be removed in order for it to survive. The exchange of these substances between the mother and fetus occurs through the placenta. The placenta is a temporary organ that starts to form shortly after implantation. It forms from the trophoblast layer of cells in the blastocyst and from maternal cells in the uterus. The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure 22.8, is made up of a large mass of blood vessels from both mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mothers and fetuss blood to exchange substances across their capillary walls without the blood actually mixing. The fetus is connected to the placenta through the umbilical cord. This is a long tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries. It exchanges gases and other substances with the mothers blood. Then it travels back to the fetus through the umbilical vein. Another structure that supports the fetus is the amniotic sac. This is a membrane that surrounds and protects the fetus. It contains amniotic fluid, which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. "
__cell that results when a sperm fertilizes an egg,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,D,"The sperm and egg dont look anything like a human baby ( Figure 1.1). After they come together, they will develop into a human being. How does a single cell become a complex organism made up of billions of cells? Keep reading to find out. Sexual reproduction happens when a sperm and an egg cell combine together. This is called fertilization. Sperm are released into the vagina during sexual intercourse. They swim through the uterus and enter a fallopian tube. This is where fertilization normally takes place. A sperm that is about to enter an egg is pictured below ( Figure 1.1). If the sperm breaks through the eggs membrane, it will immediately cause changes in the egg that keep other sperm out. This ensures that only a single sperm can penetrate an egg. It will also cause the egg to go through meiosis. Recall that meiosis, cell division that creates the egg, begins long before an egg is released from an ovary. In fact, it begins prior to birth. The sperm and egg each have only half the number of chromosomes as other cells in the body. These cells are haploid, with a single set of chromosomes. This is because when they combine together, they form a cell with the full number of chromosomes. The cell they form is called a zygote. The zygote is diploid, with two sets of chromosomes, one from each parent. A human zygote has two sets of 23 chromosomes, for a total of 46 chromosomes (23 pairs). The zygote slowly travels down the fallopian tube to the uterus. As it travels, it divides by mitosis many times. It forms a hollow ball of cells. After the ball of cells reaches the uterus, it fixes itself to the side of the uterus. This is called implantation. It usually happens about a week after fertilization. Now the implanted ball of cells is ready to continue its development into a baby boy or girl. "
__temporary organ consisting of blood vessels from both the mother and fetus,(A) aplacenta (B) bblastocyst (C) camniotic sac (D) dzygote (E) etrophoblast (F) fimplantation (G) gumbilical cord,A,"The fetus could not grow and develop without oxygen and nutrients from the mother. Wastes from the fetus also must be removed in order for it to survive. The exchange of these substances between the mother and fetus occurs through the placenta. The placenta is a temporary organ that starts to form shortly after implantation. It forms from the trophoblast layer of cells in the blastocyst and from maternal cells in the uterus. The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure 22.8, is made up of a large mass of blood vessels from both mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mothers and fetuss blood to exchange substances across their capillary walls without the blood actually mixing. The fetus is connected to the placenta through the umbilical cord. This is a long tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries. It exchanges gases and other substances with the mothers blood. Then it travels back to the fetus through the umbilical vein. Another structure that supports the fetus is the amniotic sac. This is a membrane that surrounds and protects the fetus. It contains amniotic fluid, which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. "
Which STI cannot be cured with antibiotics?,(A) gonorrhea (B) genital herpes (C) syphilis (D) chlamydia,B,"Several STIs are caused by viruses. Viral STIs cant be cured with antibiotics. Other drugs may help control the symptoms of viral STIs, but the infections usually last for life. Three viral STIs are genital warts, genital herpes, and AIDS. Genital herpes is a common STI caused by a herpes virus. The virus causes painful blisters on the penis or near the vaginal opening. The blisters generally go away on their own, but they may return repeatedly throughout life. There is no cure for genital herpes, but medicines can help prevent or shorten outbreaks. Acquired Immunodeficiency Syndrome (AIDS) is caused by human immunodeficiency virus (HIV). HIV destroys lymphocytes that normally fight infections. AIDS develops if the number of lymphocytes drops to a very low level. People with AIDS come down with diseasessuch as certain rare cancersthat almost never occur in people with a healthy immune system. Medicines can delay the progression of an HIV infection and may prevent AIDS from developing. Genital warts is an STI caused by human papilloma virus (HPV), which is pictured in Figure 22.15. This is one of the most common STIs in U.S. teens. Genital warts cant be cured, but a vaccine can prevent most HPV infections. The vaccine is recommended for boys and girls starting at 11 or 12 years of age. Its important to prevent HPV infections because they may lead to cancer later in life. "
__serious condition that may occur if tampons are not changed often,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,F,"As was discussed in previous concepts, both infectious and noninfectious diseases of the reproductive system can be very serious. But there are ways to keep your reproductive system healthy. What can you do to keep your reproductive system healthy? You can start by making the right choices for overall good health. To be as healthy as you can be, you should: Eat a balanced diet that is high in fiber and low in fat. Drink plenty of water. Get regular exercise. Maintain a healthy weight. Get enough sleep. Avoid using tobacco, alcohol, or other drugs. Manage stress in healthy ways. Keeping your genitals clean is also very important. A daily shower or bath is all that it takes. Females do not need to use special feminine hygiene products. In fact, using them may do more harm than good because they can irritate the vagina or other reproductive structures. You should also avoid other behaviors that can put you at risk. Do not get into contact with another persons blood or other body fluids. For example, never get a tattoo or piercing unless you are sure that the needles have not been used before. This is one of the most important ways to prevent an STI. Of course, the only way to be fully protected against STIs is to refrain from sexual activity. If you are a boy, you should always wear a protective cup when you play contact sports. Contact sports include football, boxing, and hockey. Wearing a cup will help protect the testes from injury. You should also do a monthly self-exam to check for cancer of the testes. If you are a girl and use tampons, be sure to change them every four to six hours. Leaving tampons in for too long can put you at risk of toxic shock syndrome. This is a serious condition. Signs and symptoms of toxic shock syndrome develop suddenly, and the disease can be fatal. The disease involves fever, shock, and problems with the function of several body organs. Girls should also get in the habit of doing a monthly self-exam to check for breast cancer. Although breast cancer is rare in teens, its a good idea to start doing the exam when you are young. It will help you get to know what is normal for you. "
__any sexually transmitted infection,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,B,"A sexually transmitted infection (STI) is a disease that spreads mainly through sexual contact. STIs are caused by pathogens that enter the body through the reproductive organs. Many STIs also spread through body fluids such as blood. For example, a shared tattoo needle is one way that some STIs can spread. Some STIs can also spread from a mother to her infant during birth. "
Most females should start regular breast cancer screening at about age,(A) 10 years (B) 20 years (C) 30 years (D) 40 years,D,"Cancer occurs most often in adults, especially adults over the age of 50. The most common types of cancer in adults differ between males and females. The most common type of cancer in adult males is cancer of the prostate gland. The prostate gland is part of the male reproductive system. About one third of all cancers in men are prostate cancers. The most common type of cancer in adult females is cancer of the breast. About one third of all cancers in women are breast cancers. In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. Childhood cancer is rare. The main type of cancer in children is leukemia. It makes up about one third of all childhood cancers. It occurs when the body makes abnormal white blood cells. "
Which age group has the greatest risk of cancer of the testes?,(A) below age 15 years (B) between ages 15 and 35 years (C) between ages 35 and 50 years (D) older than age 50 years,B,"Most common disorders of the male reproductive system involve the testes. They include injuries and cancer. Injuries to the testes are very common. In teens, such injuries occur most often while playing sports. Injuries to the testes are likely to be very painful and cause bruising and swelling. However, they generally subside fairly quickly. Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control and form a tumor. If found early, cancer of the testes usually can be cured with surgery. "
__virus that causes genital warts,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,D,"Genital warts are an STI caused by human papilloma virus, or HPV. They are one of the most common STIs in teenagers. HPV infections cannot be cured. But a new vaccine called Gardasil can prevent most HPV infections in females. Many doctors recommend that females between the ages of 9 and 26 years receive the vaccine. Preventing HPV infections in females is important because HPV can also cause cancer of the cervix. A related herpes virus causes cold sores on the lips ( Figure 1.2). Both viruses cause painful blisters. In the case of genital herpes, the blisters are on the penis or around the vaginal opening. The blisters go away on their own, but the virus remains in the body. The blisters may come back repeatedly, especially when a person is under stress. There is no cure for genital herpes. But drugs can help prevent or shorten outbreaks. Researchers are trying to find a vaccine to prevent genital herpes. Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. HIV stands for ""human immunodeficiency virus."" It is the virus that causes AIDS. HIV and AIDS are described in a previous concept. HIV can spread through sexual contact. It can also spread through body fluids such as blood. There is no cure for HIV infection, and AIDS can cause death, although AIDS can be delayed for several years with medication. Researchers are trying to find a vaccine to prevent HIV infection. "
__virus that may cause AIDS,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,G,"AIDS is not really a single disease. It is a set of symptoms and other diseases. It results from years of damage to the immune system by HIV. AIDS occurs when helper T cells fall to a very low level, making it difficult for the affected person to fight various diseases and other infections. These people develop infections or cancers that people with a healthy immune systems can easily resist. These diseases are usually the cause of death of people with AIDS. The first known cases of AIDS occurred in 1981. Since then, AIDS has led to the deaths of more than 35 million people worldwide. Many of them were children. The greatest number of deaths occurred in Africa. It is also where medications to control HIV are least available. There are currently more people infected with HIV in Africa than any other part of the world. Well over 30 million people are living with HIV worldwide. "
Ways STIs may spread include,(A) exposure to contaminated blood (B) childbirth (C) sexual contact (D) all of the above,D,"A sexually transmitted infection (STI) is a disease that spreads mainly through sexual contact. STIs are caused by pathogens that enter the body through the reproductive organs. Many STIs also spread through body fluids such as blood. For example, a shared tattoo needle is one way that some STIs can spread. Some STIs can also spread from a mother to her infant during birth. "
__viral STI that can be prevented with a vaccine,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,C,"Genital warts are an STI caused by human papilloma virus, or HPV. They are one of the most common STIs in teenagers. HPV infections cannot be cured. But a new vaccine called Gardasil can prevent most HPV infections in females. Many doctors recommend that females between the ages of 9 and 26 years receive the vaccine. Preventing HPV infections in females is important because HPV can also cause cancer of the cervix. A related herpes virus causes cold sores on the lips ( Figure 1.2). Both viruses cause painful blisters. In the case of genital herpes, the blisters are on the penis or around the vaginal opening. The blisters go away on their own, but the virus remains in the body. The blisters may come back repeatedly, especially when a person is under stress. There is no cure for genital herpes. But drugs can help prevent or shorten outbreaks. Researchers are trying to find a vaccine to prevent genital herpes. Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. HIV stands for ""human immunodeficiency virus."" It is the virus that causes AIDS. HIV and AIDS are described in a previous concept. HIV can spread through sexual contact. It can also spread through body fluids such as blood. There is no cure for HIV infection, and AIDS can cause death, although AIDS can be delayed for several years with medication. Researchers are trying to find a vaccine to prevent HIV infection. "
Which STI can be prevented with a vaccine?,(A) genital herpes (B) AIDS (C) syphilis (D) genital warts,D,"Genital warts are an STI caused by human papilloma virus, or HPV. They are one of the most common STIs in teenagers. HPV infections cannot be cured. But a new vaccine called Gardasil can prevent most HPV infections in females. Many doctors recommend that females between the ages of 9 and 26 years receive the vaccine. Preventing HPV infections in females is important because HPV can also cause cancer of the cervix. A related herpes virus causes cold sores on the lips ( Figure 1.2). Both viruses cause painful blisters. In the case of genital herpes, the blisters are on the penis or around the vaginal opening. The blisters go away on their own, but the virus remains in the body. The blisters may come back repeatedly, especially when a person is under stress. There is no cure for genital herpes. But drugs can help prevent or shorten outbreaks. Researchers are trying to find a vaccine to prevent genital herpes. Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. HIV stands for ""human immunodeficiency virus."" It is the virus that causes AIDS. HIV and AIDS are described in a previous concept. HIV can spread through sexual contact. It can also spread through body fluids such as blood. There is no cure for HIV infection, and AIDS can cause death, although AIDS can be delayed for several years with medication. Researchers are trying to find a vaccine to prevent HIV infection. "
__disease that may develop in someone infected with HIV,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,E,"AIDS is not really a single disease. It is a set of symptoms and other diseases. It results from years of damage to the immune system by HIV. AIDS occurs when helper T cells fall to a very low level, making it difficult for the affected person to fight various diseases and other infections. These people develop infections or cancers that people with a healthy immune systems can easily resist. These diseases are usually the cause of death of people with AIDS. The first known cases of AIDS occurred in 1981. Since then, AIDS has led to the deaths of more than 35 million people worldwide. Many of them were children. The greatest number of deaths occurred in Africa. It is also where medications to control HIV are least available. There are currently more people infected with HIV in Africa than any other part of the world. Well over 30 million people are living with HIV worldwide. "
__most common bacterial STI in the U.S.,(A) achlamydia (B) bSTI (C) cgenital warts (D) dHPV (E) eAIDS (F) ftoxic shock syndrome (G) gHIV,A,"A number of STIs are caused by bacteria. Bacterial STIs can usually be cured with antibiotics. However, some people with bacterial STIs may not have symptoms so they fail to get treatment. Left untreated, these infections may damage reproductive organs and lead to an inability to have children. Three bacterial STIs are chlamydia, gonorrhea, and syphilis. Chlamydia is the most common bacterial STI in the U.S. Females are more likely to develop it than males. Symptoms may include burning during urination and a discharge from the vagina or penis. Gonorrhea is another common bacterial STI. Symptoms may include painful urination and a discharge from the vagina or penis. Syphilis is a very serious STI but somewhat less common than chlamydia or gonorrhea. It usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis isnt treated, it can eventually damage the heart, brain, and other organs and even cause death. "
An STI is any medical problem that affects the reproductive organs.,(A) true (B) false,B,"A sexually transmitted infection (STI) is a disease that spreads mainly through sexual contact. STIs are caused by pathogens that enter the body through the reproductive organs. Many STIs also spread through body fluids such as blood. For example, a shared tattoo needle is one way that some STIs can spread. Some STIs can also spread from a mother to her infant during birth. "
STIs always cause symptoms.,(A) true (B) false,B,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
STIs are most common in teens and young adults.,(A) true (B) false,A,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
HIV destroys lymphocytes that normally fight infections.,(A) true (B) false,A,"How does an HIV infection develop into AIDS? HIV destroys white blood cells called helper T cells. The cells are produced by the immune system. This is the body system that fights infections and other diseases. HIV invades helper T cells and uses them to produce more virus particles ( Figure 1.1). Then, the virus kills the helper T cells. As the number of viruses in the blood rises, the number of helper T cells falls. Without helper T cells, the immune system is unable to protect the body. The infected person cannot fight infections and other diseases because they do not have T cells. This is why people do not die from HIV. Instead, they die from another illness, like the common cold, that they cannot fight because they do not have helper T cells. Medications can slow down the increase of viruses in the blood. But the medications cannot remove the viruses from the body. At present, there is no cure for HIV infection. A vaccine against HIV could stop this disease, and such a vaccine is in development, though it could take many years before it can be given to prevent this virus. "
It is normal to have abdominal cramps during menstruation.,(A) true (B) false,A,"Disorders of the female reproductive system may involve the vagina, uterus, or ovaries. They may also affect the breasts. Vaginitis is a very common disorder. Symptoms include redness and itching of the vagina. It may be caused by soap or bubble bath. Another possible cause is a yeast infection. Yeast normally grow in the vagina. If they multiple too quickly, they may cause irritation. A yeast infection can be treated with medication. Cysts may develop in the ovaries. A cyst is a sac filled with fluid or other material. Ovarian cysts are usually harmless and often disappear on their own. However, some cysts may be painful and require surgery. Many females experience abdominal cramps during menstruation. This is usually normal and not a cause for concern. Exercise, heat, or medication may help relieve the pain. In severe cases, prescription medicine may be needed. Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery. "
Many STIs can spread through body fluids such as blood.,(A) true (B) false,A,"A sexually transmitted infection (STI) is a disease that spreads mainly through sexual contact. STIs are caused by pathogens that enter the body through the reproductive organs. Many STIs also spread through body fluids such as blood. For example, a shared tattoo needle is one way that some STIs can spread. Some STIs can also spread from a mother to her infant during birth. "
A person with just one sexual partner cannot get STIs by sexual contact.,(A) true (B) false,B,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
Untreated STIs may lead to the inability to have children.,(A) true (B) false,A,"A number of STIs are caused by bacteria. Bacterial STIs can usually be cured with antibiotics. However, some people with bacterial STIs may not have symptoms so they fail to get treatment. Left untreated, these infections may damage reproductive organs and lead to an inability to have children. Three bacterial STIs are chlamydia, gonorrhea, and syphilis. Chlamydia is the most common bacterial STI in the U.S. Females are more likely to develop it than males. Symptoms may include burning during urination and a discharge from the vagina or penis. Gonorrhea is another common bacterial STI. Symptoms may include painful urination and a discharge from the vagina or penis. Syphilis is a very serious STI but somewhat less common than chlamydia or gonorrhea. It usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis isnt treated, it can eventually damage the heart, brain, and other organs and even cause death. "
Viral STIs usually last for life.,(A) true (B) false,A,"Several STIs are caused by viruses. Viral STIs cant be cured with antibiotics. Other drugs may help control the symptoms of viral STIs, but the infections usually last for life. Three viral STIs are genital warts, genital herpes, and AIDS. Genital herpes is a common STI caused by a herpes virus. The virus causes painful blisters on the penis or near the vaginal opening. The blisters generally go away on their own, but they may return repeatedly throughout life. There is no cure for genital herpes, but medicines can help prevent or shorten outbreaks. Acquired Immunodeficiency Syndrome (AIDS) is caused by human immunodeficiency virus (HIV). HIV destroys lymphocytes that normally fight infections. AIDS develops if the number of lymphocytes drops to a very low level. People with AIDS come down with diseasessuch as certain rare cancersthat almost never occur in people with a healthy immune system. Medicines can delay the progression of an HIV infection and may prevent AIDS from developing. Genital warts is an STI caused by human papilloma virus (HPV), which is pictured in Figure 22.15. This is one of the most common STIs in U.S. teens. Genital warts cant be cured, but a vaccine can prevent most HPV infections. The vaccine is recommended for boys and girls starting at 11 or 12 years of age. Its important to prevent HPV infections because they may lead to cancer later in life. "
AIDS is diagnosed in anyone who has an HIV infection.,(A) true (B) false,B,"HIV, or human immunodeficiency virus, causes AIDS. AIDS stands for ""acquired immune deficiency syndrome."" It is a condition that causes death and does not have a known cure. AIDS usually develops 10 to 15 years after a person is first infected with HIV. The development of AIDS can be delayed with proper medicines. The delay can be well over 20 years with the right medicines. Today, individuals who acquire HIV after 50 years of age can expect to reach an average human life span. "
Injuries to the testes are very rare.,(A) true (B) false,B,"Most common disorders of the male reproductive system involve the testes. For example, injuries to the testes are very common. In teenagers, injuries to the testes most often occur while playing sports. An injury such as a strike or kick to the testes can be very painful. It may also cause bruising and swelling. Such injuries do not usually last very long. Another disorder of the testes is cancer. Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control. The cells form a lump called a tumor. If found early, cancer of the testes usually can be easily cured with surgery. "
Ovarian cysts are usually harmless.,(A) true (B) false,A,"Disorders of the female reproductive system may involve the vagina, uterus, or ovaries. They may also affect the breasts. Vaginitis is a very common disorder. Symptoms include redness and itching of the vagina. It may be caused by soap or bubble bath. Another possible cause is a yeast infection. Yeast normally grow in the vagina. If they multiple too quickly, they may cause irritation. A yeast infection can be treated with medication. Cysts may develop in the ovaries. A cyst is a sac filled with fluid or other material. Ovarian cysts are usually harmless and often disappear on their own. However, some cysts may be painful and require surgery. Many females experience abdominal cramps during menstruation. This is usually normal and not a cause for concern. Exercise, heat, or medication may help relieve the pain. In severe cases, prescription medicine may be needed. Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery. "
In which of the following age groups are STIs most common?,(A) preteens (B) teens and young adults (C) middle-aged adults (D) elderly adults,B,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
What causes STIs?,(A) pathogens (B) injuries (C) environmental toxins (D) two of the above,A,"A sexually transmitted infection (STI) is an infection that spreads through sexual contact. STIs are caused by pathogens, a living thing or virus that causes infection. The pathogens enter the body through the reproductive organs. Many STIs also spread through body fluids, such as blood. For example, a shared tattoo needle is one way an STI could spread. Some STIs can also spread from a mother to her baby during childbirth. STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to take risks. They also may not know how STIs spread. They are likely to believe myths about STIs ( Table Myth If you are sexually active with just one person, you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because STIs can be cured with medicine. Fact The only way to avoid the risk of STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicine; other STIs cannot be cured. Most STIs are caused by bacteria or viruses. STIs caused by bacteria usually can be cured with drugs called antibiotics. But antibiotics are not effective against viruses. Therefore, STIs caused by viruses are not treated with antibiotics. Other drugs may be used to help control the symptoms of viral STIs, but they cannot be cured. Once you have a viral STI, you are usually infected for life. "
Which STI can be treated with antibiotics?,(A) genital herpes (B) genital warts (C) syphilis (D) AIDS,C,"A number of STIs are caused by bacteria. Bacterial STIs can usually be cured with antibiotics. However, some people with bacterial STIs may not have symptoms so they fail to get treatment. Left untreated, these infections may damage reproductive organs and lead to an inability to have children. Three bacterial STIs are chlamydia, gonorrhea, and syphilis. Chlamydia is the most common bacterial STI in the U.S. Females are more likely to develop it than males. Symptoms may include burning during urination and a discharge from the vagina or penis. Gonorrhea is another common bacterial STI. Symptoms may include painful urination and a discharge from the vagina or penis. Syphilis is a very serious STI but somewhat less common than chlamydia or gonorrhea. It usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis isnt treated, it can eventually damage the heart, brain, and other organs and even cause death. "
The most common reproductive system cancer in young males is cancer of the,(A) penis (B) testes (C) prostate gland (D) vas deferens,B,"Most common disorders of the male reproductive system involve the testes. They include injuries and cancer. Injuries to the testes are very common. In teens, such injuries occur most often while playing sports. Injuries to the testes are likely to be very painful and cause bruising and swelling. However, they generally subside fairly quickly. Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control and form a tumor. If found early, cancer of the testes usually can be cured with surgery. "
Infection with HPV may eventually lead to,(A) AIDS (B) herpes (C) cancer (D) gonorrhea,C,Pathogens that cause cancer include the human papilloma virus (HPV) ( Figure 1.1) and the hepatitis B virus. HPV is spread through sexual contact. It can cause cancer of the reproductive system in females. The hepatitis B virus is spread through sexual contact or contact with blood containing the virus. It can cause cancer of the liver. 
Which statement about STIs is false?,(A) All STIs can be cured with antibiotics (B) Many STIs do not cause symptoms (C) Some STIs can be fatal if left untreated (D) STIs may be caused by viruses or bacteria,A,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
Which STI below is linked with the wrong initial symptom?,(A) chlamydia: discharge from the genitals (B) gonorrhea: small sore on the genitals (C) syphilis: painful urination (D) two of the above,D,"A number of STIs are caused by bacteria. Bacterial STIs can usually be cured with antibiotics. However, some people with bacterial STIs may not have symptoms so they fail to get treatment. Left untreated, these infections may damage reproductive organs and lead to an inability to have children. Three bacterial STIs are chlamydia, gonorrhea, and syphilis. Chlamydia is the most common bacterial STI in the U.S. Females are more likely to develop it than males. Symptoms may include burning during urination and a discharge from the vagina or penis. Gonorrhea is another common bacterial STI. Symptoms may include painful urination and a discharge from the vagina or penis. Syphilis is a very serious STI but somewhat less common than chlamydia or gonorrhea. It usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis isnt treated, it can eventually damage the heart, brain, and other organs and even cause death. "
All organisms have the same basic needs.,(A) true (B) false,A,All ecosystems have living things that play the same basic roles. Some organisms must be producers. Others must be consumers. Decomposers are also important. 
Environmental factors can be classified as either biotic or abiotic.,(A) true (B) false,A,"All organisms have the ability to grow and reproduce. To grow and reproduce, organisms must get materials and energy from the environment. Plants obtain their energy from the sun through photosynthesis, whereas animals obtain their energy from other organisms. Either way, these plants and animals, as well as the bacteria and fungi, are constantly interacting with other species as well as the non-living parts of their ecosystem. An organisms environment includes two types of factors: 1. Abiotic factors are the parts of the environment that are not living, such as sunlight, climate, soil, water, and air. 2. Biotic factors are the parts of the environment that are alive, or were alive and then died, such as plants, animals, and their remains. Biotic factors also include bacteria, fungi and protists. Ecology studies the interactions between biotic factors, such as organisms like plants and animals, and abiotic factors. For example, all animals (biotic factors) breathe in oxygen (abiotic factor). All plants (biotic factor) absorb carbon dioxide (abiotic factor) and need water (abiotic factor) to survive. Can you think of another way that abiotic and biotic factors interact with each other? "
An individual is a single living thing.,(A) true (B) false,A,"Every organism is different from every other organism. Every organisms genes are different, too. "
Members of the same population rarely interact with each other.,(A) true (B) false,B,A population consists of all individuals of a single species that exist together at a given place and time. A species is a single type of organism that can interbreed and produce fertile offspring. All of the populations living together in the same area make up a community. 
The biotic component of a biome is a community.,(A) true (B) false,B,Biotic factors are the living parts of ecosystems. They are the species of living things that reside together. 
An ecosystem includes only biotic factors.,(A) true (B) false,B,Biotic factors are the living parts of ecosystems. They are the species of living things that reside together. 
The biosphere includes all the other levels of organization in ecology.,(A) true (B) false,A,"The highest level of ecological organization is the biosphere. It is the part of Earth, including the air, land, surface rocks, and water, where life is found. Parts of the lithosphere, hydrosphere, and atmosphere make up the biosphere. The lithosphere is the outermost layer of the Earths crust; essentially land is part of the lithosphere. The hydrosphere is composed of all the areas that contain water, which can be found on, under, and over the surface of Earth. The atmosphere is the layer of gas that surrounds the planet. The biosphere includes the area from about 11,000 meters below sea level to 15,000 meters above sea level. It overlaps with the lithosphere, hydrosphere, and atmosphere. Land plants and animals are found on the lithosphere, freshwater and marine plants and animals are found in the hydrosphere, and birds and other flying animals are found in the atmosphere. Of course, there are countless bacteria, protists, and fungi that are also found in the biosphere. "
__individual living thing,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,B,"How do you define a living thing? What do mushrooms, daisies, cats, and bacteria have in common? All of these are living things, or organisms. It might seem hard to think of similarities among such different organisms, but they actually have many properties in common. Living organisms are similar to each other because all organisms evolved from the same common ancestor that lived billions of years ago. All living organisms: 1. Need energy to carry out life processes. 2. Are composed of one or more cells. 3. Respond to their environment. 4. Grow and reproduce. 5. Maintain a stable internal environment. "
__any living or once-living aspect of the environment,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,D,"Organisms are individual living things. They range from microscopic bacteria to gigantic blue whales (see Figure must be obtained from the environment. Biotic factors are all of the living or once-living aspects of the environment. They include all the organisms that live there as well as the remains of dead organisms. Abiotic factors are all of the aspects of the environment that have never been alive. They include factors such as sunlight, minerals in soil, temperature, and moisture. "
__group of similar ecosystems,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,F,"An ecosystem is a group of living things and their environment. The word ecosystem is short for ecological system. Like any system, an ecosystem is a group of parts that work together. You can see examples of ecosystems in Figure 18.1. The forest pictured is a big ecosystem. Besides trees, what living things do you think are part of the forest ecosystem? The dead tree stump in the same forest is a small ecosystem. It includes plants, mosses, and fungi. It also includes insects and worms. "
__group of individuals of the same species that live in the same area,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,G,A population consists of all individuals of a single species that exist together at a given place and time. A species is a single type of organism that can interbreed and produce fertile offspring. All of the populations living together in the same area make up a community. 
__any aspect of the environment that has never been alive,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,A,"Organisms are individual living things. They range from microscopic bacteria to gigantic blue whales (see Figure must be obtained from the environment. Biotic factors are all of the living or once-living aspects of the environment. They include all the organisms that live there as well as the remains of dead organisms. Abiotic factors are all of the aspects of the environment that have never been alive. They include factors such as sunlight, minerals in soil, temperature, and moisture. "
__all the biotic and abiotic factors in an area and their interactions,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,E,Biotic factors are the living parts of ecosystems. They are the species of living things that reside together. 
__all the populations of all the species that live in the same area,(A) aabiotic factor (B) borganism (C) ccommunity (D) dbiotic factor (E) eecosystem (F) fbiome (G) gpopulation,C,All the members of a species that live in the same area form a population. Many different species live together in an ecosystem. All their populations make up a community. What populations live together in the grassland in Figure 
Ecology shares data and theories with the science(s) of,(A) geography (B) biology (C) climatology (D) all of the above,D,"Ecology involves many different fields, including geology, soil science, geography, meteorology, genetics, chemistry, and physics. You can also divide ecology into the study of different organisms, such as animal ecology, plant ecology, insect ecology, and so on. Ecologists also study biomes. A biome is a large community of plants and animals that live in the same place. For example, ecologists can study the biomes as diverse as the Arctic, the tropics, or the desert ( Figure 1.1). They may want to know why different species live in different biomes. They may want to know what would make a particular biome or ecosystem stable. Can you think of other aspects of a biome or ecosystem that ecologists could study? Ecologists do two types of research: An example of a biome, the Atacama Desert, in Chile. 1. Field studies. 2. Laboratory studies. Field studies involve collecting data outside in the natural world. An ecologist who completes a field study may travel to a tropical rainforest to study, count, and classify all of the insects that live in a certain area. Laboratory studies involve working inside, usually in a controlled environment. Sometimes, ecologists collect data from the field, and then they analyze that data in the lab. Also, they use computer programs to predict what will happen to organisms that live in a specific area. For example, they may make predictions about what happens to insects in the rainforest after a fire. "
What do all living things need from their environment?,(A) sunlight (B) energy (C) matter (D) two of the above,D,"All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ecosystems. "
Biotic factors in the environment include,(A) remains of dead organisms (B) minerals in the soil (C) temperature (D) two of the above,A,Biotic factors are the living parts of ecosystems. They are the species of living things that reside together. 
An ecosystem consists of,(A) biotic factors (B) abiotic factors (C) a community (D) all of the above,D,"An ecosystem is a group of living things and their environment. The word ecosystem is short for ecological system. Like any system, an ecosystem is a group of parts that work together. You can see examples of ecosystems in Figure 18.1. The forest pictured is a big ecosystem. Besides trees, what living things do you think are part of the forest ecosystem? The dead tree stump in the same forest is a small ecosystem. It includes plants, mosses, and fungi. It also includes insects and worms. "
Ecosystems in a biome have the same general,(A) consumers (B) abiotic factors (C) populations (D) all of the above,B,"A climate type and its plants and animals make up a biome. The organisms of a biome share certain characteristics around the world, because their environment has similar advantages and challenges. The organisms have adapted to that environment in similar ways over time. For example, different species of cactus live on different continents, but they have adapted to the harsh desert in similar ways. Click image to the left or use the URL below. URL: "
Which choice shows levels of organization in ecology from smaller to larger?,(A) individual ! community ! population (B) ecosystem ! biome ! biosphere (C) community ! biome ! ecosystem (D) population ! ecosystem ! community,B,"Ecosystems can be studied at small levels or at large levels. The levels of organization are described below from the smallest to the largest: A species is a group of individuals that are genetically related and can breed to produce fertile young. Individuals are not members of the same species if their members cannot produce offspring that can also have children. The second word in the two word name given to every organism is the species name. For example, in Homo sapiens, sapiens is the species name. A population is a group of organisms belonging to the same species that live in the same area and interact with one another. A community is all of the populations of different species that live in the same area and interact with one another. A community is composed of all of the biotic factors of an area. An ecosystem includes the living organisms (all the populations) in an area and the non-living aspects of the environment ( Figure 1.1). An ecosystem is made of the biotic and abiotic factors in an area. Satellite image of Australias Great Barrier Reef, an example of a marine ecosys- tem. The biosphere is the part of the planet with living organisms ( Figure 1.2). The biosphere includes most of Earth, including part of the oceans and the atmosphere. Ecologists study ecosystems at every level, from the individual organism to the whole ecosystem and biosphere. They can ask different types of questions at each level. Examples of these questions are given in Table 1.1, using the zebra (Equus zebra) as an example. Ecosystem Level Individual Population Community Ecosystem Question How do zebras keep water in their bodies? What causes the growth of a zebra populations? How does a disturbance, like a fire or predator, affect the number of mammal species in African grasslands? How does fire affect the amount of food available in grassland ecosystems? "
Abiotic factors in the environment include all of the following except,(A) organic wastes (B) moisture (C) temperature (D) minerals,A,"Abiotic factors are the nonliving parts of ecosystems. They include air, sunlight, soil, water, and minerals. These are all things that are needed for life. They determine which living things  and how many of them  an ecosystem can support. Figure 18.2 shows an ecosystem and its abiotic factors. "
The total human population reached 7 billion people by the year,(A) 1000 (B) 1700 (C) 1914 (D) 2014,D,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
The demographic transition is a model based on what actually occurred in,(A) the poorest nations of the world (B) Western Europe and North America (C) all human populations worldwide (D) none of the above,B,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
The human species evolved in Africa. Human beings first left Africa about,(A) 200 (B) 000 years ago (C) b 100 (D) 000 years ago (E) c 40 (F) 000 years ago (G) d 10 (H) 000 years ago,C,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
"At its current rate of growth, the human population will surpass 9 billion by the year",(A) 2020 (B) 2030 (C) 2040 (D) 2050,D,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
Factors that influence the rate of growth of a population include,(A) births (B) deaths (C) migration (D) all of the above,D,"For a population to be healthy, factors such as food, nutrients, water and space, must be available. What happens when there are not resources to support the population? Limiting factors are resources or other factors in the environment that can lower the population growth rate. Limiting factors include a low food supply and lack of space. Limiting factors can lower birth rates, increase death rates, or lead to emigration. When organisms face limiting factors, they show logistic growth (S-shaped curve, curve B: Figure 1.1). Compe- tition for resources like food and space cause the growth rate to stop increasing, so the population levels off. This flat upper line on a growth curve is the carrying capacity. The carrying capacity (K) is the maximum population size that can be supported in a particular area without destroying the habitat. Limiting factors determine the carrying capacity of a population. Recall that when there are no limiting factors, the population grows exponentially. In exponential growth (J-shaped curve, curve A: Figure 1.1), as the population size increases, the growth rate also increases. Exponential and Logistic Growth. Curve A shows exponential growth. shows logistic growth. Curve B Notice that the carrying capacity (K) is also shown. "
The most common pattern of population distribution is a random pattern.,(A) true (B) false,B,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
Only births and deaths change the size of a population.,(A) true (B) false,B,Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. 
A pattern of exponential population growth generally cannot continue for very long.,(A) true (B) false,A,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
The age-sex structure of a population may influence the populations growth rate.,(A) true (B) false,A,"Another way of describing a population is its age-sex structure. This refers to the numbers of individuals of each sex and age in the population. The age-sex structure of a population may influence the population growth rate. This is because only individuals of certain ages are able to reproduce, and because individuals of certain ages may be more likely to die. For example, if there are many individuals of reproductive age, there are likely to be many births, causing the population to grow rapidly. The age-sex structure of a population is often represented with a special bar graph called a population pyramid. You can see an example of a population pyramid in Figure 23.5. The graph in the figure actually has a pyramid shape because the bars become narrower from younger to older ages. However, this is not always the case. In some populations, for example, there may be more people at older than younger ages, resulting in a top-heavy population pyramid. Learn more about population pyramids and what you can learn from them, watch this TED video: http://w MEDIA Click image to the left or use the URL below. URL: "
The size and growth rate of its populations influences the chances of a species surviving.,(A) true (B) false,A,"Population size is the number of individuals in a population. Population size influences the chances of a species surviving or going extinct. If a species populations become very small, the species may be at risk of going extinct. "
A random pattern of population distribution is typical of species in which individuals compete for,(A) true (B) false,B,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
"The human population started growing very rapidly about 10,000 years ago.",(A) true (B) false,B,"Figure 18.17 shows how the human population has grown. It grew very slowly for tens of thousands of years. Then, in the 1800s, something happened to change all that. The human population started to grow much faster. "
A population pyramid is a graphic representation of the age-sex structure of a population.,(A) true (B) false,A,"Another way of describing a population is its age-sex structure. This refers to the numbers of individuals of each sex and age in the population. The age-sex structure of a population may influence the population growth rate. This is because only individuals of certain ages are able to reproduce, and because individuals of certain ages may be more likely to die. For example, if there are many individuals of reproductive age, there are likely to be many births, causing the population to grow rapidly. The age-sex structure of a population is often represented with a special bar graph called a population pyramid. You can see an example of a population pyramid in Figure 23.5. The graph in the figure actually has a pyramid shape because the bars become narrower from younger to older ages. However, this is not always the case. In some populations, for example, there may be more people at older than younger ages, resulting in a top-heavy population pyramid. Learn more about population pyramids and what you can learn from them, watch this TED video: http://w MEDIA Click image to the left or use the URL below. URL: "
Many countries today remain in stage 1 of the demographic transition.,(A) true (B) false,B,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
The human population is predicted to exceed 9 billion by the year 2050.,(A) true (B) false,A,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
"Overall, the human population has had a pattern of exponential growth.",(A) true (B) false,A,"How quickly is the human population growing? If we look at worldwide human population growth from 10,000 BCE through today, our growth looks like exponential growth. It increased very slowly at first, but later grew faster and faster as the population increased in size ( Figure 1.1). And recently, the human population has increased at a faster pace than ever before. It has taken only 12 years for the worlds population to increase from six billion to seven billion. Considering that in the year 1804, there were just one billion people, and in 1927, there were just two billion people (thats 123 years to increase from 1 to 2 billion), the recent increase in the human population growth rate is characteristic of exponential growth. Does this mean there are unlimited resources? Worldwide human population growth from 10,000 BCE through today. "
Major changes in human population growth rates first began in the 1700s.,(A) true (B) false,A,"Figure 18.17 shows how the human population has grown. It grew very slowly for tens of thousands of years. Then, in the 1800s, something happened to change all that. The human population started to grow much faster. "
__way in which individuals in a population are spread over their area,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,F,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
__pattern of population growth in which the rate of growth keeps increasing as the population gets,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,D,"Whether its populations are growing or shrinking in size may be another indicator of a species health. Individuals may be added to a population through births and the migration of individuals into the population. Individuals may be lost from a population through deaths and the migration of individuals out of the population. The population growth rate is how quickly a population changes in size over time. The rate of growth of a population may be positive or negative. A positive growth rate means that the population is increasing in size because more people are being added than lost. A negative growth rate means that the population is decreasing in size because more people are being lost than added. Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure 23.4. With exponential growth, the population starts out growing slowly. As population size increases, the growth rate also increases. The larger the population becomes, the more quickly it grows. This type of growth generally occurs only when a population is living under ideal conditions. However, it cant continue for very long. With logistic growth, the population starts out growing slowly, and then the rate of growth increasesbut only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations. "
__how quickly population size changes over time,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,E,"Whether its populations are growing or shrinking in size may be another indicator of a species health. Individuals may be added to a population through births and the migration of individuals into the population. Individuals may be lost from a population through deaths and the migration of individuals out of the population. The population growth rate is how quickly a population changes in size over time. The rate of growth of a population may be positive or negative. A positive growth rate means that the population is increasing in size because more people are being added than lost. A negative growth rate means that the population is decreasing in size because more people are being lost than added. Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure 23.4. With exponential growth, the population starts out growing slowly. As population size increases, the growth rate also increases. The larger the population becomes, the more quickly it grows. This type of growth generally occurs only when a population is living under ideal conditions. However, it cant continue for very long. With logistic growth, the population starts out growing slowly, and then the rate of growth increasesbut only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations. "
__largest population size that can be supported in an area without harming the environment,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,A,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
__average number of individuals in a population for a given area,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,C,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
__numbers of individuals of each age and sex in a population,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,B,"Another way of describing a population is its age-sex structure. This refers to the numbers of individuals of each sex and age in the population. The age-sex structure of a population may influence the population growth rate. This is because only individuals of certain ages are able to reproduce, and because individuals of certain ages may be more likely to die. For example, if there are many individuals of reproductive age, there are likely to be many births, causing the population to grow rapidly. The age-sex structure of a population is often represented with a special bar graph called a population pyramid. You can see an example of a population pyramid in Figure 23.5. The graph in the figure actually has a pyramid shape because the bars become narrower from younger to older ages. However, this is not always the case. In some populations, for example, there may be more people at older than younger ages, resulting in a top-heavy population pyramid. Learn more about population pyramids and what you can learn from them, watch this TED video: http://w MEDIA Click image to the left or use the URL below. URL: "
__pattern of population growth in which the rate of growth slows as the population nears the carrying,(A) acarrying capacity (B) bage-sex structure (C) cpopulation density (D) dexponential growth (E) epopulation growth rate (F) fpopulation distribution (G) glogistic growth,G,"Whether its populations are growing or shrinking in size may be another indicator of a species health. Individuals may be added to a population through births and the migration of individuals into the population. Individuals may be lost from a population through deaths and the migration of individuals out of the population. The population growth rate is how quickly a population changes in size over time. The rate of growth of a population may be positive or negative. A positive growth rate means that the population is increasing in size because more people are being added than lost. A negative growth rate means that the population is decreasing in size because more people are being lost than added. Populations may show different patterns of growth. The growth pattern depends partly on the conditions under which a population lives. Two common growth patterns are exponential growth and logistic growth. Both are represented in Figure 23.4. With exponential growth, the population starts out growing slowly. As population size increases, the growth rate also increases. The larger the population becomes, the more quickly it grows. This type of growth generally occurs only when a population is living under ideal conditions. However, it cant continue for very long. With logistic growth, the population starts out growing slowly, and then the rate of growth increasesbut only to a point. The rate of growth tapers off as the population size approaches its carrying capacity. Carrying capacity is the largest population size that can be supported in an area without harming the environment. This type of growth characterizes many populations. "
The population is the unit of,(A) natural selection (B) adaptation (C) microevolution (D) all of the above,D,A population consists of all individuals of a single species that exist together at a given place and time. A species is a single type of organism that can interbreed and produce fertile offspring. All of the populations living together in the same area make up a community. 
"If a population of 80 foxes lives in an area of 8 square kilometers, what is the fox population density?",(A) 80 foxes per square kilometer (B) 64 foxes per square kilometer (C) 10 foxes per square kilometer (D) 8 foxes per square kilometer,C,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
In which pattern of population distribution are organisms evenly spaced over the area they occupy?,(A) random (B) clumped (C) uniform (D) none of the above,C,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
What does a positive population growth rate mean?,(A) Fewer people are being added than lost (B) The population is increasing in size (C) The population has reached its carrying capacity (D) two of the above,B,What does population growth mean? You can probably guess that it means the number of individuals in a population is increasing. The population growth rate tells you how quickly a population is increasing or decreasing. What determines the population growth rate for a particular population? 
The human species first evolved about,(A) 10 (B) 000 years ago (C) b 40 (D) 000 years ago (E) c 100 (F) 000 years ago (G) d 200 (H) 000 years ago,D,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
The demographic transition,(A) began in the 1700s (B) occurred first in Africa (C) happened in two stages (D) included an increase in the birth rate,A,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
About how many human beings presently live on Earth?,(A) 7 million (B) 1 billion (C) 5 billion (D) 7 billion,D,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
Which statement is always true of ecosystems in the same biome?,(A) They have the same type of primary producers (B) They are located on the same continent (C) They have similar abiotic factors (D) two of the above,D,"There are many different types of ecosystems. Climate conditions determine which ecosystems are found in a particular location. A biome encompasses all of the ecosystems that have similar climate and organisms. Different organisms live in different types of ecosystems because they are adapted to different conditions. Lizards thrive in deserts, but no reptiles are found in any polar ecosystems. Amphibians cant live too far from the water. Large animals generally do better in cold climates than in hot climates. Despite this, every ecosystem has the same general roles that living creatures fill. Its just the organisms that fill those niches that are different. For example, every ecosystem must have some organisms that produce food in the form of chemical energy. These organisms are primarily algae in the oceans, plants on land, and bacteria at hydrothermal vents. "
All ecosystems at the same latitude are placed in the same biome.,(A) true (B) false,B,"There are many different types of ecosystems. Climate conditions determine which ecosystems are found in a particular location. A biome encompasses all of the ecosystems that have similar climate and organisms. Different organisms live in different types of ecosystems because they are adapted to different conditions. Lizards thrive in deserts, but no reptiles are found in any polar ecosystems. Amphibians cant live too far from the water. Large animals generally do better in cold climates than in hot climates. Despite this, every ecosystem has the same general roles that living creatures fill. Its just the organisms that fill those niches that are different. For example, every ecosystem must have some organisms that produce food in the form of chemical energy. These organisms are primarily algae in the oceans, plants on land, and bacteria at hydrothermal vents. "
Ecosystems in the same biome have the same type of primary producers.,(A) true (B) false,A,"Plants are the primary producers in terrestrial biomes. They make food for themselves and other organisms by photosynthesis. The major plants in a given biome, in turn, help determine the types of animals and other organisms that can live there. Which plants grow in a given biome depends mainly on climate. Climate is the average weather in a place over a long period of time. The major climatic factors affecting plant growth are temperature and moisture. "
Which of the following is not a type of tropical biome?,(A) tundra (B) rainforest (C) dry forest (D) desert,A,"A terrestrial biome is an area of land with a similar climate that includes similar communities of plants and animals. Different terrestrial biomes are usually defined in terms of their plants, such as trees, shrubs, and grasses. Factors such as latitude, humidity, and elevation affect biome type: Latitude means how far a biome is from the equator. Moving from the poles to the equator, you will find (in order) Arctic, boreal, temperate, subtropical, and tropical biomes. Humidity is the amount of water in the air. Air with a high concentration of water will be called humid. Moving away from the most humid climate, biomes will be called semi-humid, semi-arid, or arid (the driest). Elevation measures how high land is above sea level. It gets colder as you go higher above sea level, which is why you see snow-capped mountains. Terrestrial biomes include grasslands, forests, deserts, and tundra. Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees and include the savanna and temperate grasslands. Forests are dominated by trees and other woody vegetation and are classified based on their latitude. Forests include tropical, temperate, and boreal forests (taiga). Deserts cover about one fifth of the Earths surface and occur where rainfall is less than 50 cm (about 20 inches) each year. Tundra is the coldest of all the biomes. The tundra is characterized for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. There are two main types of tundra, Arctic and Alpine tundras. Terrestrial biomes ( Figure 1.1) lying within the Arctic and Antarctic Circles do not have very much plant or animal life. Biomes with the highest amount of biodiversity, that is the most variation in plant and animal life, are near the equator ( Figure 1.2). One of the terrestrial biomes, taiga, is an evergreen forest of the subarctic, covering extensive areas of northern North Amer- ica and Eurasia. This taiga is along the Denali Highway in Alaska. "
A temperate grassland has,(A) a wet climate (B) many deciduous trees (C) excellent soil quality (D) two of the above,C,"Pedocal soil forms where grasses and brush are common (Figure 9.11). The climate is drier, with less than 65 cm of rain per year. With less rain, there is less chemical weathering. There is less organic material and the soils are slightly less fertile. "
Plants are the primary producers in all of Earths biomes.,(A) true (B) false,B,"Plants are the primary producers in terrestrial biomes. They make food for themselves and other organisms by photosynthesis. The major plants in a given biome, in turn, help determine the types of animals and other organisms that can live there. Which plants grow in a given biome depends mainly on climate. Climate is the average weather in a place over a long period of time. The major climatic factors affecting plant growth are temperature and moisture. "
Which plants grow in a particular biome depends mainly on climate.,(A) true (B) false,A,"Plants are the primary producers in terrestrial biomes. They make food for themselves and other organisms by photosynthesis. The major plants in a given biome, in turn, help determine the types of animals and other organisms that can live there. Which plants grow in a given biome depends mainly on climate. Climate is the average weather in a place over a long period of time. The major climatic factors affecting plant growth are temperature and moisture. "
The primary producers in most aquatic biomes are,(A) plants (B) zooplankton (C) phytoplankton (D) none of the above,C,"Aquatic biomes are water-based biomes. They include both freshwater biomes, such as rivers and lakes, and marine biomes, which are salt-water biomes in the ocean. The primary producers in most aquatic biomes are phytoplankton. Phytoplankton consist of microscopic bacteria and tiny algae that make food by photosynthesis. Unlike terrestrial biomes, which are determined mainly by temperature and moisture, aquatic biomes are determined mainly by sunlight and dissolved substances in the water. These factors, in turn, depend mainly on depth of water and distance from shore. "
Arctic tundra is found only at low latitudes.,(A) true (B) false,B,"Polar climates are found near the North and South Poles. They also occur on high mountains at lower latitudes. The summers are very cool, and the winters are frigid. Precipitation is very low because its so cold. You can see examples of polar climates in Figure 17.14. Polar tundra climates occur near the poles. Tundra climates have permafrost. Permafrost is layer of ground below the surface that is always frozen, even in the summer. Only small plants, such as mosses, can grow in this climate. Alpine tundra climates occur at high altitudes at any latitude. They are also called highland climates. These regions are very cold because they are so far above sea level. The alpine tundra climate is very similar to the polar tundra climate. Ice caps are areas covered with thick ice year round. Ice caps are found only in Greenland and Antarctica. Temperatures and precipitation are both very low. What little snow falls usually stays on the ground. It doesnt melt because its too cold. "
The most important factors that determine the nature of aquatic biomes include,(A) sunlight (B) latitude (C) temperature (D) precipitation,A,"Aquatic biomes are water-based biomes. They include both freshwater biomes, such as rivers and lakes, and marine biomes, which are salt-water biomes in the ocean. The primary producers in most aquatic biomes are phytoplankton. Phytoplankton consist of microscopic bacteria and tiny algae that make food by photosynthesis. Unlike terrestrial biomes, which are determined mainly by temperature and moisture, aquatic biomes are determined mainly by sunlight and dissolved substances in the water. These factors, in turn, depend mainly on depth of water and distance from shore. "
Rivers and lakes are examples of marine biomes.,(A) true (B) false,B,"Aquatic biomes in the ocean are called marine biomes. Organisms that live in marine biomes must be adapted to the salt in the water. For example, many have organs for excreting excess salt. Marine biomes include the oceans, coral reefs, and estuaries ( Figure 1.1). The oceans are the largest of all the ecosystems. They can be divided into four separate zones based on the amount of sunlight. Ocean zones are also divided based on their depth and their distance from land. Each zone has a great diversity of species. Within a coral reef, the dominant organisms are corals. Corals consist partially of algae, which provide nutrients via photosynthesis. Corals also extend tentacles to obtain plankton from the water. Coral reefs include several species of microorganisms, invertebrates, fishes, sea urchins, octopuses, and sea stars. Estuaries are areas where freshwater streams or rivers merge with the ocean. An example of a marine biome, a kelp for- est, from Anacapa Island in the Channel Islands National Marine Sanctuary. "
Deep water generally contains more dissolved oxygen than water near the surface.,(A) true (B) false,B,"Water in lakes and the ocean also varies in the amount of dissolved oxygen and nutrients it contains: 1. Water near the surface of lakes and the ocean usually has more dissolved oxygen than does deeper water. This is because surface water absorbs oxygen from the air above it. 2. Water near shore generally has more dissolved nutrients than water farther from shore. This is because most nutrients enter the water from land. They are carried by runoff, streams, and rivers that empty into a body of water. 3. Water near the bottom of lakes and the ocean may contain more nutrients than water closer to the surface. When aquatic organisms die, they sink to the bottom. Decomposers near the bottom of the water break down the dead organisms and release their nutrients back into the water. "
__primary producers in most aquatic biomes,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,E,"Aquatic biomes are water-based biomes. They include both freshwater biomes, such as rivers and lakes, and marine biomes, which are salt-water biomes in the ocean. The primary producers in most aquatic biomes are phytoplankton. Phytoplankton consist of microscopic bacteria and tiny algae that make food by photosynthesis. Unlike terrestrial biomes, which are determined mainly by temperature and moisture, aquatic biomes are determined mainly by sunlight and dissolved substances in the water. These factors, in turn, depend mainly on depth of water and distance from shore. "
__shallow water near the shore of a lake,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,D,"A lake is an example of a freshwater biome. Water in a lake generally forms three different zones based on water depth and distance from shore. The shallow water near the shore is called the littoral zone. It has diverse community of organisms. There is adequate light for photosynthesis and plenty of dissolved oxygen and nutrients. Producers include algae and aquatic plants (see Figure 23.20). Animals in this zone may include insects, crustaceans, fish, and turtles. The top layer of water farther from shore is called the limnetic zone. There is enough light for photosynthesis and plenty of dissolved oxygen. However, dissolved nutrients tend not to be as plentiful as they are in the littoral zone. Producers here are mainly phytoplankton. A variety of zooplankton and fish also occupy this zone. The deeper water of a lake makes up the profundal zone. There isnt enough light for photosynthesis in this zone, so most organisms here eat dead organisms that drift down from the water above. Organisms in the profundal zone may include clams, snails, and some species of fish. "
__part of a body of water that is too deep for sunlight to reach,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,G,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
__general term for a group of similar ecosystems,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,B,"An ecosystem is a group of living things and their environment. The word ecosystem is short for ecological system. Like any system, an ecosystem is a group of parts that work together. You can see examples of ecosystems in Figure 18.1. The forest pictured is a big ecosystem. Besides trees, what living things do you think are part of the forest ecosystem? The dead tree stump in the same forest is a small ecosystem. It includes plants, mosses, and fungi. It also includes insects and worms. "
The littoral zone of a lake is the deep water near the bottom.,(A) true (B) false,B,"Limnology is the study of bodies of fresh water and the organisms that live there. A lake has zones just like the ocean. The ecosystem of a lake is divided into three distinct zones (Figure 1.1): 1. The surface (littoral) zone is the sloped area closest to the edge of the water. 2. The open-water zone (also called the photic or limnetic zone) has abundant sunlight. 3. The deep-water zone (also called the aphotic or profundal zone) has little or no sunlight. There are several life zones found within a lake: In the littoral zone, sunlight promotes plant growth, which provides food and shelter to animals such as snails, insects, and fish. In the open-water zone, other plants and fish, such as bass and trout, live. The deep-water zone does not have photosynthesis since there is no sunlight. Most deep-water organisms are scavengers, such as crabs and catfish that feed on dead organisms that fall to the bottom of the lake. Fungi and bacteria aid in the decomposition in the deep zone. Though different creatures live in the oceans, ocean waters also have these same divisions based on sunlight with similar types of creatures that live in each of the zones. The three primary zones of a lake are the littoral, open-water, and deep-water zones. "
"In aquatic biomes, water closer to shore usually contains more dissolved nutrients than water farther",(A) true (B) false,A,"In addition to sunlight, aquatic producers also need dissolved oxygen and nutrients. Water near the surface generally contains more dissolved oxygen than deeper water. Many nutrients enter the water from the land. Therefore, water nearer shore usually contains more dissolved nutrients than water farther from shore. "
__top 200 meters of a body of water,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,A,"In large bodies of water, such as the ocean and lakes, the water can be divided into zones based on the amount of sunlight it receives: 1. The photic zone extends to a maximum depth of 200 meters (656 feet) below the surface of the water. This is where enough sunlight penetrates for photosynthesis to occur. Algae and other photosynthetic organisms can make food and support food webs. 2. The aphotic zone is water deeper than 200 meters. This is where too little sunlight penetrates for photosyn- thesis to occur. As a result, producers must make ""food"" by chemosynthesis, or the food must drift down from the water above. "
All the water in the open ocean far from shore is called the pelagic zone.,(A) true (B) false,A,"Zones in the oceans include the intertidal, pelagic, and benthic zones. The types of organisms found in these ocean zones are also determined by such factors as depth of water and distance from shore, among other factors. One of the most familiar ocean zones is the intertidal zone. This is the narrow strip along a coastline that is covered by water at high tide and exposed to air at low tide. You can see an example of an intertidal zone in Figure 23.21. There are plenty of nutrients and sunlight in the intertidal zone. Producers here include phytoplankton and algae. Other organisms include barnacles, snails, crabs, and mussels. They must have adaptations for the constantly changing conditions in this zone. Other ocean zones are farther from shore in the open ocean. All the water in the open ocean is called the pelagic zone. It is further divided by depth: The top 200 meters of water is the photic zone. Producers here include seaweeds and phytoplankton. Other organisms are plentiful. They include zooplankton and animals such as fish, whales, and dolphins. "
__average weather in a place over a long period of time,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,C,Climate is the average weather of a place over many years. It includes average temperatures. It also includes average precipitation. The timing of precipitation is part of climate as well. What determines the climate of a place? Latitude is the main factor. A nearby ocean or mountain range can also play a role. 
__of or relating to the ocean,(A) aphotic zone (B) bbiome (C) cclimate (D) dlittoral zone (E) ephytoplankton (F) fmarine (G) gaphotic zone,F,"Oceanography is the study of everything in the ocean environment, which covers about 70% of the Earths surface. Recent technology has allowed people and probes to venture to the deepest parts of the ocean, but much of the ocean remains unexplored. Marine geologists learn about the rocks and geologic processes of the ocean basins. "
There is not enough sunlight for photosynthesis in the aphotic zone of a body of water.,(A) true (B) false,A,"Only the top 200 meters or so of water receive enough sunlight for photosynthesis. This part of the water is called the photic zone. Below 200 meters, there is too little sunlight for photosynthesis to take place. This part of the water is called the aphotic zone. In this zone, food must come from other sources. It may be made by chemosynthesis, in which microorganisms use energy in chemicals instead of sunlight to make food. Or, food may drift down from the water above. "
The benthic zone of the ocean includes the sediments at the bottom of the water.,(A) true (B) false,A,"The seabed is divided into the zones described above, but ocean itself is also divided horizontally by distance from the shore. Nearest to the shore lies the intertidal zone (also called the littoral zone), the region between the high and low tidal marks. The hallmark of the intertidal is change: water is in constant motion in the form of waves, tides, and currents. The land is sometimes under water and sometimes exposed. The neritic zone is from low tide mark and slopes gradually downward to the edge of the seaward side of the continental shelf. Some sunlight penetrates to the seabed here. The oceanic zone is the entire rest of the ocean from the bottom edge of the neritic zone, where sunlight does not reach the bottom. The sea bed and water column are subdivided further, as seen in the Figure 1.1. Click image to the left or use the URL below. URL: "
Terrestrial biomes include all of the following except,(A) tropical dry forests (B) alpine tundra (C) polar forests (D) boreal rainforests,C,Terrestrial biomes are land-based biomes. They range from arctic tundra to tropical rainforests. Figure 23.18 shows the locations of the worlds major terrestrial biomes. 
Which of the following is not a type of temperate biome?,(A) deciduous forest (B) desert (C) rainforest (D) savanna,D,"A terrestrial biome is an area of land with a similar climate that includes similar communities of plants and animals. Different terrestrial biomes are usually defined in terms of their plants, such as trees, shrubs, and grasses. Factors such as latitude, humidity, and elevation affect biome type: Latitude means how far a biome is from the equator. Moving from the poles to the equator, you will find (in order) Arctic, boreal, temperate, subtropical, and tropical biomes. Humidity is the amount of water in the air. Air with a high concentration of water will be called humid. Moving away from the most humid climate, biomes will be called semi-humid, semi-arid, or arid (the driest). Elevation measures how high land is above sea level. It gets colder as you go higher above sea level, which is why you see snow-capped mountains. Terrestrial biomes include grasslands, forests, deserts, and tundra. Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees and include the savanna and temperate grasslands. Forests are dominated by trees and other woody vegetation and are classified based on their latitude. Forests include tropical, temperate, and boreal forests (taiga). Deserts cover about one fifth of the Earths surface and occur where rainfall is less than 50 cm (about 20 inches) each year. Tundra is the coldest of all the biomes. The tundra is characterized for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. There are two main types of tundra, Arctic and Alpine tundras. Terrestrial biomes ( Figure 1.1) lying within the Arctic and Antarctic Circles do not have very much plant or animal life. Biomes with the highest amount of biodiversity, that is the most variation in plant and animal life, are near the equator ( Figure 1.2). One of the terrestrial biomes, taiga, is an evergreen forest of the subarctic, covering extensive areas of northern North Amer- ica and Eurasia. This taiga is along the Denali Highway in Alaska. "
A tropical rainforest has,(A) very high biodiversity (B) a humid climate (C) a year-round growing season (D) all of the above,D,"Tropical moist climates are found in a band about 15o to 25o N and S of the Equator (Figure 1.1). Temperature: Intense sunshine. Each month has an average temperature of at least 18o C (64o F). Rainfall: Abundant, at least 150 cm (59 inches) per year. The main vegetation for this climate is the tropical rainforest. "
The main factors that determine aquatic biomes include,(A) temperature (B) types of plants (C) dissolved substances (D) two of the above,C,"Aquatic biomes are water-based biomes. They include both freshwater biomes, such as rivers and lakes, and marine biomes, which are salt-water biomes in the ocean. The primary producers in most aquatic biomes are phytoplankton. Phytoplankton consist of microscopic bacteria and tiny algae that make food by photosynthesis. Unlike terrestrial biomes, which are determined mainly by temperature and moisture, aquatic biomes are determined mainly by sunlight and dissolved substances in the water. These factors, in turn, depend mainly on depth of water and distance from shore. "
The limnetic zone of a lake has,(A) enough light for photosynthesis (B) more dissolved nutrients than any other lake zone (C) less dissolved oxygen than any other lake zone (D) none of the above,A,"Limnology is the study of bodies of fresh water and the organisms that live there. A lake has zones just like the ocean. The ecosystem of a lake is divided into three distinct zones (Figure 1.1): 1. The surface (littoral) zone is the sloped area closest to the edge of the water. 2. The open-water zone (also called the photic or limnetic zone) has abundant sunlight. 3. The deep-water zone (also called the aphotic or profundal zone) has little or no sunlight. There are several life zones found within a lake: In the littoral zone, sunlight promotes plant growth, which provides food and shelter to animals such as snails, insects, and fish. In the open-water zone, other plants and fish, such as bass and trout, live. The deep-water zone does not have photosynthesis since there is no sunlight. Most deep-water organisms are scavengers, such as crabs and catfish that feed on dead organisms that fall to the bottom of the lake. Fungi and bacteria aid in the decomposition in the deep zone. Though different creatures live in the oceans, ocean waters also have these same divisions based on sunlight with similar types of creatures that live in each of the zones. The three primary zones of a lake are the littoral, open-water, and deep-water zones. "
The types of plants found in tundra biomes include,(A) mosses (B) grasses (C) trees (D) two of the above,D,"A terrestrial biome is an area of land with a similar climate that includes similar communities of plants and animals. Different terrestrial biomes are usually defined in terms of their plants, such as trees, shrubs, and grasses. Factors such as latitude, humidity, and elevation affect biome type: Latitude means how far a biome is from the equator. Moving from the poles to the equator, you will find (in order) Arctic, boreal, temperate, subtropical, and tropical biomes. Humidity is the amount of water in the air. Air with a high concentration of water will be called humid. Moving away from the most humid climate, biomes will be called semi-humid, semi-arid, or arid (the driest). Elevation measures how high land is above sea level. It gets colder as you go higher above sea level, which is why you see snow-capped mountains. Terrestrial biomes include grasslands, forests, deserts, and tundra. Grasslands are characterized as lands dominated by grasses rather than large shrubs or trees and include the savanna and temperate grasslands. Forests are dominated by trees and other woody vegetation and are classified based on their latitude. Forests include tropical, temperate, and boreal forests (taiga). Deserts cover about one fifth of the Earths surface and occur where rainfall is less than 50 cm (about 20 inches) each year. Tundra is the coldest of all the biomes. The tundra is characterized for its frost-molded landscapes, extremely low temperatures, little precipitation, poor nutrients, and short growing seasons. There are two main types of tundra, Arctic and Alpine tundras. Terrestrial biomes ( Figure 1.1) lying within the Arctic and Antarctic Circles do not have very much plant or animal life. Biomes with the highest amount of biodiversity, that is the most variation in plant and animal life, are near the equator ( Figure 1.2). One of the terrestrial biomes, taiga, is an evergreen forest of the subarctic, covering extensive areas of northern North Amer- ica and Eurasia. This taiga is along the Denali Highway in Alaska. "
Reptiles live in all of the following biomes except,(A) tundra (B) tropical rainforest (C) tropical dry forest (D) temperate grassland,A,Modern reptiles live in many different habitats. They can be found on every continent except Antarctica. 
Reservoirs for water in the water cycle include,(A) glaciers (B) the ocean (C) organisms (D) two of the above,D,"The movement of water around Earths surface is the hydrological (water) cycle (Figure 1.1). Water inhabits reservoirs within the cycle, such as ponds, oceans, or the atmosphere. The molecules move between these reservoirs by certain processes, including condensation and precipitation. There are only so many water molecules and these molecules cycle around. If climate cools and glaciers and ice caps grow, there is less water for the oceans and sea level will fall. The reverse can also happen. The following section looks at the reservoirs and the processes that move water between them. "
The ocean is a reservoir in the carbon cycle.,(A) true (B) false,A,"Carbon from decaying organisms enters the ground. Some carbon is stored in the soil. Some carbon may be stored underground for millions of years. This will form fossil fuels. When volcanoes erupt, carbon from the mantle is released as carbon dioxide into the air. Producers take in the carbon dioxide to make food. Then the cycle repeats. The oceans also play an important role in the carbon cycle. Ocean water absorbs carbon dioxide from the air. In fact, the oceans contain 50 times more carbon than the atmosphere. Much of the carbon sinks to the bottom of the oceans, where it may stay for hundreds of years. "
Life on Earth could not exist without water.,(A) true (B) false,A,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
Precipitation may include,(A) fog (B) dew (C) sleet (D) all of the above,C,"Clouds are needed for precipitation. This may fall as liquid water, or it may fall as frozen water, such as snow. "
How can groundwater continue through the water cycle?,(A) It may seep out of the ground at a spring (B) It may seep into a body of water such as the ocean (C) It may be pumped out of the ground through a well (D) all of the above,D,"Water may seep through dirt and rock below the soil and then through pores infiltrating the ground to go into Earths groundwater system. Groundwater enters aquifers that may store fresh water for centuries. Alternatively, the water may come to the surface through springs or find its way back to the oceans. "
Individual water molecules may be billions of years old.,(A) true (B) false,A,"Did you ever wonder where the water in your glass came from or where its been? The next time you take a drink of water, think about this. Each water molecule has probably been around for billions of years. Thats because Earths water is constantly recycled. "
Water changes to a gas by the process of condensation.,(A) true (B) false,B,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
Exchange pools for carbon include,(A) living things (B) sedimentary rocks (C) the ocean (D) two of the above,A,"Major exchange pools of carbon include organisms and the atmosphere. Carbon cycles more quickly between these components of the carbon cycle. Photosynthesis by plants and other producers removes carbon dioxide from the atmosphere to make organic compounds for living things. Cellular respiration by living things releases carbon into the atmosphere or ocean as carbon dioxide. Decomposition of dead organisms and organic wastes releases carbon back to the atmosphere, soil, or ocean. "
Water in clouds is in the gaseous state.,(A) true (B) false,B,"Water vapor is not visible unless it condenses to become a cloud. Water vapor condenses around a nucleus, such as dust, smoke, or a salt crystal. This forms a tiny liquid droplet. Billions of these water droplets together make a cloud. "
What percent of Earths atmosphere is nitrogen?,(A) 22 percent (B) 28 percent (C) 52 percent (D) 78 percent,D,"Nitrogen and oxygen together make up 99% of the planets atmosphere. Nitrogen makes up the bulk of the atmosphere, but is not involved in geological or biological processes in its gaseous form. Nitrogen fixing is described in the chapter Life on Earth. Oxygen is extremely important because it is needed by animals for respiration. The rest of the gases are minor components but sometimes are very important (Figure 1.1). Nitrogen and oxygen make up 99% of the atmosphere; carbon dioxide is a very important minor component. "
Most precipitation falls on land.,(A) true (B) false,B,"Most precipitation that occurs over land, however, is not absorbed by the soil and is called runoff. This runoff collects in streams and rivers and eventually flows back into the ocean. "
Volcanic eruptions can release underground carbon from rocks into the atmosphere.,(A) true (B) false,A,"Carbon from decaying organisms enters the ground. Some carbon is stored in the soil. Some carbon may be stored underground for millions of years. This will form fossil fuels. When volcanoes erupt, carbon from the mantle is released as carbon dioxide into the air. Producers take in the carbon dioxide to make food. Then the cycle repeats. The oceans also play an important role in the carbon cycle. Ocean water absorbs carbon dioxide from the air. In fact, the oceans contain 50 times more carbon than the atmosphere. Much of the carbon sinks to the bottom of the oceans, where it may stay for hundreds of years. "
Exchange pools for water include,(A) the atmosphere (B) polar ice caps (C) aquifers (D) all of the above,A,"People love water for swimming, fishing, boating, river rafting, and other activates. Even activities such as golf, where there may not be any standing water, require plenty of water to make the grass on the course green. Despite its value, the amount of water that most recreational activities use is low: less than 1% of all the water we use. Many recreational water uses are non-consumptive including swimming, fishing, and boating. Golf courses are the biggest recreational water consumer since they require large amounts for irrigation, especially because many courses are located in warm, sunny, desert regions where water is scarce and evaporation is high. "
Which statement about the water cycle is false?,(A) The water cycle is a global cycle (B) The water cycle takes place only on and above Earths surface (C) In the water cycle (D) water exists in three different states (E) d Water cycle processes include condensation,B,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
How do solid carbon compounds change to carbon dioxide in the atmosphere during the carbon cycle?,(A) cellular respiration by living things (B) photosynthesis by photoautotrophs (C) decomposition of dead organisms (D) two of the above,D,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
What role do plants called legumes play in the nitrogen cycle?,(A) Their roots change nitrogen gas in the air into nitrates (B) Their roots provide a home for nitrogen-fixing bacteria (C) Their leaves transpire nitrogen gas into the atmosphere (D) Their leaves change ammonium ions into nitrogen gas,B,"Nitrogen is another common element found in living things. It is needed to form both proteins and nucleic acids such as DNA. Nitrogen gas makes up 78 percent of Earths atmosphere. In the nitrogen cycle, nitrogen flows back and forth between the atmosphere and living things. You can see how it happens in Figure 24.10. Several different types of bacteria play major roles in the cycle. Animals get nitrogen by eating plants or other organisms that eat plants. Where do plants get nitrogen? They cant use nitrogen gas in the air. The only form of nitrogen that plants can use is in chemical compounds called nitrates. Plants absorb nitrates through their roots. This is called assimilation. Most of the nitrates are produced by bacteria that live in soil or in the roots of plants called legumes. Nitrogen-fixing bacteria change nitrogen gas from the atmosphere to nitrates in soil. When organisms die and decompose, their nitrogen is returned to the soil as ammonium ions. Nitrifying bacteria change some of the ammonium ions into nitrates. The other ammonium ions are changed into nitrogen gas by denitrifying bacteria. "
The only form of nitrogen that plants can use is nitrogen gas.,(A) true (B) false,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
Nitrogen-fixing bacteria change ammonium ions into nitrogen gas.,(A) true (B) false,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
All of the following processes are part of the water cycle except,(A) transpiration (B) sublimation (C) evaporation (D) decomposition,D,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
The atmosphere is an exchange pool for water.,(A) true (B) false,A,"We are lucky to have an atmosphere on Earth. The atmosphere supports life, and is also needed for the water cycle and weather. The gases of the atmosphere even allow us to hear. "
Nitrogen gas is released into the soil by,(A) nitrogen-fixing bacteria (B) denitrifying bacteria (C) decomposers (D) two of the above,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
The process in which plants absorb nitrates through their roots is called,(A) nitrification (B) denitrification (C) assimilation (D) ammonification,C,"Animals eat plant tissue and create animal tissue. After a plant or animal dies or an animal excretes waste, bacteria and some fungi in the soil fix the organic nitrogen and return it to the soil as ammonia. Nitrifying bacteria oxidize the ammonia to nitrites, while other bacteria oxidize the nitrites to nitrates, which can be used by the next generation of plants. In this way, nitrogen does not need to return to a gas. Under conditions when there is no oxygen, some bacteria can reduce nitrates to molecular nitrogen. Click image to the left or use the URL below. URL: "
Water keeps changing state as it moves through the water cycle.,(A) true (B) false,A,"Water keeps changing state as it goes through the water cycle. This means that it can be a solid, liquid, or gas. How does water change state? How does it keep moving through the cycle? As Figure 13.3 shows, several processes are involved. Evaporation changes liquid water to water vapor. Energy from the Sun causes water to evaporate. Most evaporation is from the oceans because they cover so much area. The water vapor rises into the atmosphere. Transpiration is like evaporation because it changes liquid water to water vapor. In transpiration, plants release water vapor through their leaves. This water vapor rises into the atmosphere. Condensation changes water vapor to liquid water. As air rises higher into the atmosphere, it cools. Cool air can hold less water vapor than warm air. So some of the water vapor condenses into water droplets. Water droplets may form clouds. Precipitation is water that falls from clouds to Earths surface. Water droplets in clouds fall to Earth when they become too large to stay aloft. The water falls as rain if the air is warm. If the air is cold, the water may freeze and fall as snow, sleet, or hail. Most precipitation falls into the oceans. Some falls on land. Runoff is precipitation that flows over the surface of the land. This water may travel to a river, lake, or ocean. Runoff may pick up fertilizer and other pollutants and deliver them to the water body where it ends up. In this way, runoff may pollute bodies of water. Infiltration is the process by which water soaks into the ground. Some of the water may seep deep under- ground. Some may stay in the soil, where plants can absorb it with their roots. In all these ways, water keeps cycling. The water cycle repeats over and over again. Who knows? Maybe a water molecule that you drink today once quenched the thirst of a dinosaur. "
Plants release water vapor to the atmosphere through their leaves.,(A) true (B) false,A,"Plants and animals depend on water to live. They also play a role in the water cycle. Plants take up water from the soil and release large amounts of water vapor into the air through their leaves (Figure 1.3), a process known as transpiration. "
__process in which water vapor changes to liquid water,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,F,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
__part of a biogeochemical cycle that holds a substance for a long period of time,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,A,"The chemical elements and water that are needed by living things keep recycling on Earth. They pass back and forth through biotic and abiotic components of ecosystems. Thats why their cycles are called biogeochemical cycles. For example, a chemical element or water might move from organisms (bio) to the atmosphere or ocean (geo) and back to organisms again. Elements or water may be held for various periods of time in different parts of a biogeochemical cycle. An exchange pool is part of a cycle that holds a substance for a short period of time. For example, the atmosphere is an exchange pool for water. It usually holds water (as water vapor) for just a few days. A reservoir is part of a cycle that holds a substance for a long period of time. For example, the ocean is a reservoir for water. It may hold water for thousands of years. The rest of this lesson describes three biogeochemical cycles: water cycle, carbon cycle, and nitrogen cycle. "
__water that falls as precipitation and then flows over the surface of the land,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,D,Precipitation that falls on land may flow over the surface of the ground. This water is called runoff. It may eventually flow into a body of water. Some precipitation that falls on land soaks into the ground. This water becomes groundwater. Groundwater may seep out of the ground at a spring or into a body of water such as the ocean. Some groundwater is taken up by plant roots. Some may flow deeper underground to an aquifer. An aquifer is an underground layer of rock that stores water. Water may be stored in an aquifer for thousands of years. 
__biogeochemical cycle that includes sedimentary rocks and fossil fuels,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,C,"Can you name some fossils? How about dinosaur bones or dinosaur footprints? Animal skeletons, teeth, shells, coprolites (otherwise known as feces), or any other remains or traces from a living creature that becomes rock is a fossil. The same processes that formed these fossils also created some of our most important energy resources, fossil fuels. Coal, oil, and natural gas are fossil fuels. Fossil fuels come from living matter starting about 500 million years ago. Millions of years ago, plants used energy from the Sun to form sugars, carbohydrates, and other energy-rich carbon compounds. As plants and animals died, their remains settled on the ground on land and in swamps, lakes, and seas (Figure 1.1). Over time, layer upon layer of these remains accumulated. Eventually, the layers were buried so deeply that they were crushed by an enormous mass of earth. The weight of this earth pressing down on these plant and animal remains created intense heat and pressure. After millions of years of heat and pressure, the material in these layers turned into chemicals called hydrocarbons (Figure 1.2). Hydrocarbons are made of carbon and hydrogen atoms. This molecule with one carbon and four hydrogen atoms is methane. Hydrocarbons can be solid, liquid, or gaseous. The solid form is what we know as coal. The liquid form is petroleum, or crude oil. Natural gas is the gaseous form. The solar energy stored in fossil fuels is a rich source of energy. Although fossil fuels provide very high quality energy, they are non-renewable. Click image to the left or use the URL below. URL: "
__part of a biogeochemical cycle that holds a substance for a short period of time,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,E,"The chemical elements and water that are needed by living things keep recycling on Earth. They pass back and forth through biotic and abiotic components of ecosystems. Thats why their cycles are called biogeochemical cycles. For example, a chemical element or water might move from organisms (bio) to the atmosphere or ocean (geo) and back to organisms again. Elements or water may be held for various periods of time in different parts of a biogeochemical cycle. An exchange pool is part of a cycle that holds a substance for a short period of time. For example, the atmosphere is an exchange pool for water. It usually holds water (as water vapor) for just a few days. A reservoir is part of a cycle that holds a substance for a long period of time. For example, the ocean is a reservoir for water. It may hold water for thousands of years. The rest of this lesson describes three biogeochemical cycles: water cycle, carbon cycle, and nitrogen cycle. "
__biogeochemical cycle that includes the atmosphere and several types of bacteria,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,G,"The chemical elements and water that are needed by living things keep recycling on Earth. They pass back and forth through biotic and abiotic components of ecosystems. Thats why their cycles are called biogeochemical cycles. For example, a chemical element or water might move from organisms (bio) to the atmosphere or ocean (geo) and back to organisms again. Elements or water may be held for various periods of time in different parts of a biogeochemical cycle. An exchange pool is part of a cycle that holds a substance for a short period of time. For example, the atmosphere is an exchange pool for water. It usually holds water (as water vapor) for just a few days. A reservoir is part of a cycle that holds a substance for a long period of time. For example, the ocean is a reservoir for water. It may hold water for thousands of years. The rest of this lesson describes three biogeochemical cycles: water cycle, carbon cycle, and nitrogen cycle. "
__process in which snow and ice change directly to water vapor,(A) areservoir (B) bsublimation (C) ccarbon cycle (D) drunoff (E) eexchange pool (F) fcondensation (G) gnitrogen cycle,B,"When water falls from the sky as rain it may enter streams and rivers that flow downward to oceans and lakes. Water that falls as snow may sit on a mountain for several months. Snow may become part of the ice in a glacier, where it may remain for hundreds or thousands of years. Snow and ice may go directly back into the air by sublimation, the process in which a solid changes directly into a gas without first becoming a liquid. Although you probably have not seen water vapor undergoing sublimation from a glacier, you may have seen dry ice sublimate in air. Snow and ice slowly melt over time to become liquid water, which provides a steady flow of fresh water to streams, rivers, and lakes below. A water droplet falling as rain could also become part of a stream or a lake. At the surface, the water may eventually evaporate and reenter the atmosphere. "
Air pollution is due mainly to,(A) natural processes (B) human actions (C) climatic changes (D) weather patterns,B,"Most air pollutants come from burning fossil fuels or plant material. Some are the result of evaporation from human- made materials. Nearly half (49%) of air pollution comes from transportation, 28% from factories and power plants, and the remaining pollution from a variety of other sources. "
__main gas that is causing global climate change,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,G,Natural processes caused earlier climate changes. Human beings are the main cause of recent global warming. 
__naturally occurring radioactive gas that may pollute indoor air,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,F,"One source of indoor air pollution is radon gas. Radon is a radioactive gas that may seep into buildings from rocks underground. Exposure to radon gas may cause lung cancer. Another potential poison in indoor air is carbon monoxide. It may be released by faulty or poorly vented furnaces or other fuel-burning appliances. Indoor furniture, carpets, and paints may release toxic compounds into the air as well. Other possible sources of indoor air pollution include dust, mold, and pet dander. "
Which of the following is both an indoor and an outdoor air pollutant?,(A) mold (B) VOCs (C) carbon monoxide (D) all of the above,C,"You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. "
Consequences of global climate change include,(A) more extreme weather (B) species extinctions (C) rising sea levels (D) all of the above,D,"The following images show changes in the Earth and organisms as a result of global warming: Figure 1.2, Figure (a) Breakup of the Larsen Ice Shelf in Antarctica in 2002 was related to climate warming in the region. (b) The Boulder Glacier has melted back tremendously since 1985. Other mountain glaciers around the world are also melting. The timing of events for species is changing. Mating and migrations take place earlier in the spring months. Species that can are moving their ranges uphill. Some regions that were already marginal for agriculture are no longer arable because they have become too warm or dry. What are the two major effects being seen in this animation? Glaciers are melting and vegetation zones are moving uphill. If fossil fuel use exploded in the 1950s, why do these changes begin early in the animation? Does this mean that the climate change we are seeing is caused by natural processes and not by fossil fuel use? Permafrost is melting and its extent de- creasing. There are now fewer summer lakes in Siberia. (a) Melting ice caps add water to the oceans, so sea level is rising. Remember that water slightly expands as it warms this expansion is also causing sea level to rise. (b) Weather is becoming more variable with more severe storms and droughts. Snow blanketed the west- ern United States in December 2009. (c) As surface seas warm, phytoplankton productivity has decreased. (d) Coral reefs are dying worldwide; corals that are stressed by high temperatures turn white. (e) Pine beetle infestations have killed trees in western North America The insects have expanded their ranges into areas that were once too cold. Warming temperatures are bringing changes to much of the planet, including California. Sea level is rising, snow pack is changing, and the ecology of the state is responding to these changes. Click image to the left or use the URL below. URL: "
__air pollutant produced by burning coal that causes acid rain,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,D,"Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. If acid rain falls into lakes, it lowers the pH of the water and may kill aquatic organisms. If it falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may make them sick or even kill them. Acid rain also damages stone buildings, bridges, and statues, like the one in Figure 25.1. "
__air pollutant caused by motor vehicle exhaust that worsens respiratory problems,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,B,"Outdoor air pollution causes serious human health problems. For example, pollutants in the air are major contributors to respiratory and cardiovascular diseases. Air pollution may trigger asthma attacks and heart attacks in people with underlying health problems. In fact, more people die each year from air pollution than automobile accidents. "
Exposure to radon gas may cause cancer of the,(A) skin (B) lung (C) kidney (D) colon,B,Forms of radiation that cause cancer include ultraviolet (UV) radiation and radon ( Figure 1.3). UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a natural radioactive gas that seeps into buildings from the ground. It can cause lung cancer. 
__toxic gas that may be released by faulty fuel-burning appliances,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,C,"One source of indoor air pollution is radon gas. Radon is a radioactive gas that may seep into buildings from rocks underground. Exposure to radon gas may cause lung cancer. Another potential poison in indoor air is carbon monoxide. It may be released by faulty or poorly vented furnaces or other fuel-burning appliances. Indoor furniture, carpets, and paints may release toxic compounds into the air as well. Other possible sources of indoor air pollution include dust, mold, and pet dander. "
Volatile organic compounds are found in some,(A) furniture (B) flooring (C) paints (D) all of the above,D,"Volatile organic compounds (VOCs) enter the atmosphere by evaporation. VOCs evaporate from human-made substances, such as paint thinners, dry cleaning solvents, petroleum, wood preservatives, and other liquids. Naturally occurring VOCs evaporate off of pine and citrus trees. The atmosphere contains tens of thousands of different VOCs, A forest that has been slash-and-burned to make new farmland. nearly 100 of which are monitored. The most common is methane, a greenhouse gas (Figure 1.3). Methane occurs naturally, but human agriculture is increasing the amount of methane in the atmosphere. Methane forms when organic material decomposes in an oxygen-poor environment. In the top image, surface methane production is shown. Stratospheric methane concentrations in the bottom image show that methane is carried up into the stratosphere by the upward flow of air in the tropics. "
__any harmful substance released into the atmosphere,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,A,"Mercury is released into the atmosphere when coal is burned (Figure 1.1). But breathing the mercury is not harmful. In the atmosphere, the mercury forms small droplets that are deposited in water or sediments. "
__natural feature of Earths atmosphere that warms Earths surface,(A) aair pollution (B) bground-level ozone (C) ccarbon monoxide (D) dsulfur oxide (E) egreenhouse effect (F) fradon (G) gcarbon dioxide,E,"The exception to Earths temperature being in balance is caused by greenhouse gases. But first the role of greenhouse gases in the atmosphere must be explained. Greenhouse gases warm the atmosphere by trapping heat. Some of the heat that radiates out from the ground is trapped by greenhouse gases in the troposphere. Like a blanket on a sleeping person, greenhouse gases act as insulation for the planet. The warming of the atmosphere because of insulation by greenhouse gases is called the greenhouse effect (Figure 1.1). Greenhouse gases are the component of the atmosphere that moderate Earths temperatures. "
Earths atmosphere is too vast to become seriously polluted.,(A) true (B) false,B,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
Cardiovascular diseases may be worsened by air pollution.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
Erosion of soil adds dust particles to the atmosphere.,(A) true (B) false,A,"Bad farming practices and a return to normal rainfall levels after an unusually wet period led to the Dust Bowl. In some regions more than 75% of the topsoil blew away. This is the most extreme example of soil erosion the United States has ever seen. Still, in many areas of the world, the rate of soil erosion is many times greater than the rate at which it is forming. Drought, insect plagues, or outbreaks of disease are natural cycles of events that can negatively impact ecosystems and the soil, but there are also many ways in which humans neglect or abuse this important resource. Soils can also be contaminated if too much salt accumulates in the soil or where pollutants sink into the ground. One harmful practice is removing the vegetation that helps to hold soil in place. Sometimes just walking or riding your bike over the same place will kill the grass that normally grows there. Land is also deliberately cleared or deforested for wood. The loose soils then may be carried away by wind or running water. A farmer and his sons walk through a dust storm in Cimarron County, Oklahoma in 1936. Click image to the left or use the URL below. URL: "
Fewer people die each year from air pollution than automobile accidents.,(A) true (B) false,B,Human health suffers in locations with high levels of air pollution. 
Earth had no greenhouse gases until about 200 years ago.,(A) true (B) false,B,An atmosphere is the gases that surround a planet. The early Earth had no atmosphere. Conditions were so hot that gases were not stable. 
Air pollution is no longer a major problem in the U.S.,(A) true (B) false,B,"By 1970, it was clear that something needed to be done to protect air quality. In the U.S., the Clean Air Act was passed. It limits what can be released into the air. As a result, the air in the U.S. is much cleaner now than it was 50 years ago. But air pollution has not gone away. Vehicles, factories, and power plants still release more than 150 million tons of pollutants into the air each year. "
Heart attacks may be triggered by pollutants in the air.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
Acid rain may kill animals but does not affect plants.,(A) true (B) false,B,"Acid rain takes a toll on ecosystems (Figure 1.4). Plants that are exposed to acids become weak and are more likely to be damaged by bad weather, insect pests, or disease. Snails die in acid soils, so songbirds do not have as much food to eat. Young birds and mammals do not build bones as well and may not be as strong. Eggshells may also be weak and break more easily. As lakes become acidic, organisms die off. No fish can live if the pH drops below 4.5. Organic material cannot decay, and mosses take over the lake. Wildlife that depend on the lake for drinking water suffer population declines. Crops are damaged by acid rain. This is most noticeable in poor nations where people cant afford to fix the problems with fertilizers or other technology. Acid rain has killed trees in this forest in the Czech Republic. Acid rain damages cultural monuments like buildings and statues. These include the U.S. Capitol and many buildings in Europe, such as Westminster Abbey. Carbonate rocks neutralize acids and so some regions do not suffer the effects of acid rain nearly as much. Limestone in the midwestern United States protects the area. One reason that the northeastern United States is so vulnerable to acid rain damage is that the rocks are not carbonates. Because pollutants can travel so far, much of the acid rain that falls hurts states or nations other than ones where the pollutants were released. All the rain that falls in Sweden is acidic and fish in lakes all over the country are dying. The pollutants come from the United Kingdom and Western Europe, which are now working to decrease their emissions. Canada also suffers from acid rain that originates in the United States, a problem that is also improving. Southeast Asia is experiencing more acid rain between nations as the region industrializes. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Earth had no greenhouse effect until human beings started burning fossil fuels.,(A) true (B) false,B,Natural processes caused earlier climate changes. Human beings are the main cause of recent global warming. 
Outdoor air is always more polluted than indoor air.,(A) true (B) false,B,"You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. "
Air pollution is a major contributor to respiratory diseases.,(A) true (B) false,A,"Outdoor air pollution causes serious human health problems. For example, pollutants in the air are major contributors to respiratory and cardiovascular diseases. Air pollution may trigger asthma attacks and heart attacks in people with underlying health problems. In fact, more people die each year from air pollution than automobile accidents. "
It is easier to control the quality of indoor air than outdoor air.,(A) true (B) false,A,"Its easier to control the quality of indoor air than outdoor air. Steps home owners can take to improve indoor air quality include: keeping the home clean so it is as free as possible from dust, mold, and pet dander. choosing indoor furniture, flooring, and paints that are low in toxic compounds such as VOCs (volatile organic compounds). making sure that fuel-burning appliances are working correctly and venting properly. installing carbon monoxide alarms like the one in Figure 25.4 at every level of the home. "
The major cause of outdoor air pollution is,(A) use of chemicals such as fertilizers (B) erosion of disturbed soil (C) burning of fossil fuels (D) ranching activities,C,"The major cause of outdoor air pollution is the burning of fossil fuels. Fossil fuels are burned in power plants, factories, motor vehicles, and home heating systems. Ranching and using chemicals such as fertilizers also cause outdoor air pollution. Erosion of soil in farm fields, mining activities, and construction sites adds dust particles to the air as well. Some specific outdoor air pollutants are described in Table 25.1. Air Pollutant Sulfur oxides Nitrogen oxides Carbon monoxide Carbon dioxide Particles (dust, smoke) Mercury Smog Ground-level ozone Source coal burning motor vehicle exhaust motor vehicle exhaust all fossil fuel burning wood and coal burning coal burning coal burning motor vehicle exhaust Problem acid rain acid rain poisoning global climate change respiratory problems nerve poisoning respiratory problems respiratory problems "
Carbon monoxide is,(A) a major cause of global climate change (B) a toxic gas that may pollute indoor air (C) one of the chief causes of acid rain (D) two of the above,B,"Carbon monoxide (CO) is toxic to both plants and animals. CO is deadly to people in a confined space, such as a closed home. Carbon monoxide is odorless and colorless, so people cant tell when they are breathing it. Thats why homes should have carbon monoxide detectors. You can see one in Figure 22.7. "
The main sources of pollutants that form acid rain include,(A) mining activities (B) coal burning (C) motor vehicle exhaust (D) two of the above,D,"Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. If acid rain falls into lakes, it lowers the pH of the water and may kill aquatic organisms. If it falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may make them sick or even kill them. Acid rain also damages stone buildings, bridges, and statues, like the one in Figure 25.1. "
Consequences of acid rain may include,(A) destruction of stone buildings (B) deaths of aquatic organisms (C) damage to soil (D) all of the above,D,"Figure 22.11 shows some of the damage done by acid rain. Acid rain ends up in soil and bodies of water. This can make them very acidic. The acid strips soil of its nutrients. These changes can kill trees, fish, and other living things. Acid rain also dissolves limestone and marble. This can damage buildings, monuments, and statues. "
What are VOCs?,(A) toxic compounds released by some furniture and paints (B) nerve poisons produced by the burning of fossil fuels (C) deadly gases released by poorly vented furnaces (D) none of the above,A,"VOCs are toxic to humans and other living things. In people, they can cause a wide range of problems, from eye and nose irritation to brain damage and cancer. Levels of VOCs are often higher indoors than out. Thats because they are released by products such as paints, cleaning solutions, and building materials. How might you reduce your exposure to VOCs? "
Fossils fuels are burned in,(A) power plants (B) motor vehicles (C) factories (D) all of the above,D,"Fossil fuels are mixtures of hydrocarbons that formed over millions of years from the remains of dead organisms. They include petroleum (commonly called oil), natural gas, and coal. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes. You can see examples of their use in Figure 17.19. Fossil fuels contain stored chemical energy that came originally from the sun. Ancient plants changed energy in "
Which of the following is a common indoor and outdoor air pollutant?,(A) dust (B) radon (C) pet dander (D) ground-level ozone,A,"Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesnt get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk. Indoor air pollutants include both chemical and biological pollutants. Chemical pollutants include the following: Radon, a radioactive gas released from the Earth in certain locations. It can become trapped inside buildings and increase your risk of cancer. Formaldehyde, a toxic gas emitted from building materials, such as carpeting and plywood. Volatile organic compounds (VOCs), which are given off by paint and solvents as they dry. They can cause cause long-term health effects. Secondhand smoke, which comes from breathing the smoke release from tobacco products. Secondhand smoke is also the smoke exhaled by a cigarette smoker. This smoke is extremely dangerous to human health. Carbon monoxide (CO), a toxic gas released by burning fossil fuels. It is often released indoors by faulty chimneys, gas-powered generators, or burning charcoal; it can be extremely dangerous. Dry cleaning fluids, such as tetrachloroethylene, which can be released from clothing days after dry cleaning. The past use of asbestos in factories and in homes. Asbestos is a very dangerous material, and it was used in many buildings ( Figure 1.1). Asbestos can cause cancer and other lung diseases. The use of asbestos is not allowed today. The use of asbestos in industry and do- mestic environments in the past, as in the asbestos-covered pipes in the oil-refining plant pictured here, has left a potentially very dangerous material in many busi- nesses. Biological sources of air pollution are also found indoors. These are produced from: Pet dander. Dust from tiny skin flakes and decomposed hair. Dust mites. Mold from walls, ceilings, and other structures. Air conditioning systems that can incubate certain bacteria and mold. Pollen, dust, and mold from houseplants, soil, and surrounding gardens. "
Most of Earths liquid water is in,(A) lakes (B) rivers (C) wetlands (D) the ocean,D,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
__problem resulting from too much dissolved carbon dioxide in ocean water,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,E,"Ocean water normally dissolves some of the carbon dioxide in the atmosphere. The burning of fossil fuels has increased the amount of carbon dioxide in the atmosphere. As a result, ocean water is also dissolving more carbon dioxide. When carbon dioxide dissolves in water, it forms a weak acid. With higher levels of dissolved carbon dioxide in ocean water, the water becomes more acidic. This process is called ocean acidification. Ocean acidification can kill some aquatic organisms, including corals and shellfish. It may make it more difficult for other aquatic organisms to reproduce. Both effects of acidification interfere with marine food webs, threatening the survival of many aquatic organisms. "
__main way that nonpoint-source pollution enters bodies of water,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,D,"Unlike runoff, which enters bodies of water everywhere, some sources of pollution enter the water at a single point. This type of water pollution is called point-source pollution. "
Runoff dissolves fertilizer when it flows over,(A) farm fields (B) golf courses (C) lawns and gardens (D) all of the above,D,"Runoff from crops, livestock, and poultry farming carries contaminants such as fertilizers, pesticides, and animal waste into nearby waterways (Figure 1.3). Soil and silt also run off farms. Animal wastes may carry harmful diseases, particularly in the developing world. The high density of animals in a factory farm means that runoff from the area is full of pollutants. Fertilizers that run off of lawns and farm fields are extremely harmful to the environment. Nutrients, such as nitrates, in the fertilizer promote algae growth in the water they flow into. With the excess nutrients, lakes, rivers, and bays become clogged with algae and aquatic plants. Eventually these organisms die and decompose. Decomposition uses up all the dissolved oxygen in the water. Without oxygen, large numbers of plants, fish, and bottom-dwelling animals die. "
The most effective way to prevent dead zones in bodies of water is to,(A) add nutrients to the water (B) reduce the use of fertilizers (C) promote the growth of algae (D) allow algal blooms to decompose,B,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
__main source of chemicals that cause algal blooms,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,C,"When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. You can see one in Figure 25.5. The algae out-compete other water organisms. They may make the water unfit for human consumption or recreation. "
__area where water cannot support aquatic life because it is hypoxic,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,F,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
Thermal pollution of water is generally caused by,(A) nonpoint-source pollution (B) home heating systems (C) power plants and factories (D) global warming,C,"If heated water is released into a body of water, it may cause thermal pollution. Thermal pollution is a reduction in the quality of water because of an increase in water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and factories. This water is heated and then returned to the natural environment at a higher temperature. Warm water cant hold as much dissolved oxygen as cool water, so an increase in the temperature of water decreases the amount of oxygen it contains. Fish and other organisms adapted to a particular temperature range and oxygen concentration may be killed by the change in water temperature. "
__reduction in water quality due to an increase in water temperature,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,G,"If heated water is released into a body of water, it may cause thermal pollution. Thermal pollution is a reduction in the quality of water because of an increase in water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and factories. This water is heated and then returned to the natural environment at a higher temperature. Warm water cant hold as much dissolved oxygen as cool water, so an increase in the temperature of water decreases the amount of oxygen it contains. Fish and other organisms adapted to a particular temperature range and oxygen concentration may be killed by the change in water temperature. "
The dissolved oxygen content of water may be reduced by,(A) thermal pollution (B) decomposition of algae (C) unusually cold weather (D) two of the above,D,"Water in lakes and the ocean also varies in the amount of dissolved oxygen and nutrients it contains: 1. Water near the surface of lakes and the ocean usually has more dissolved oxygen than does deeper water. This is because surface water absorbs oxygen from the air above it. 2. Water near shore generally has more dissolved nutrients than water farther from shore. This is because most nutrients enter the water from land. They are carried by runoff, streams, and rivers that empty into a body of water. 3. Water near the bottom of lakes and the ocean may contain more nutrients than water closer to the surface. When aquatic organisms die, they sink to the bottom. Decomposers near the bottom of the water break down the dead organisms and release their nutrients back into the water. "
__excessive growth of aquatic producers,(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,A,"In a marine ecosystem, algae are the producers. Through photosynthesis, they provide glucose for the ecosystem. So, can too much algae be a bad thing? Eutrophication is an over-enrichment of chemical nutrients in a body of water. Usually these nutrients are the nitrogen and phosphorous found in fertilizers. Run-off from lawns or farms can wash fertilizers into rivers or coastal waters. Plants are not the only things that grow more quickly with added fertilizers. Algae like the excess nutrients in fertilizers too. When there are high levels of nutrients in the water, algae populations will grow large very quickly. This leads to overgrowths of algae called algal blooms. However, these algae do not live very long. They die and begin to decompose. This process uses oxygen, removing the oxygen from the water. Without oxygen, fish and shellfish cannot live, and this results in the death of these organisms ( Figure 1.1). Certain types of algal blooms can also create toxins. These toxins can enter shellfish. If humans eat these shellfish, then they can get very sick. These toxins cause neurological problems in humans. "
"__habitat with moist soil, such as a swamp",(A) aalgal bloom (B) bwetland (C) cfertilizer (D) drunoff (E) eacidification (F) fdead zone (G) gthermal pollution,B,"A swamp is a wetland with lush trees and vines found in low-lying areas beside slow-moving rivers (Figure 1.3). Like marshes, they are frequently or always inundated with water. Since the water in a swamp moves slowly, oxygen in the water is often scarce. Swamp plants and animals must be adapted for these low-oxygen conditions. Like marshes, swamps can be fresh water, salt water, or a mixture of both. "
Trash that pollutes the ocean is made mainly of plastic.,(A) true (B) false,A,"One way that the ocean is becoming polluted is with trash, mainly plastics. The waste comes from shipping accidents, landfill erosion, and the dumping of trash. Plastics may take hundreds or even thousands of years to break down. In the meantime, the waste can be very dangerous to aquatic organisms. Some organisms may swallow plastic bags, for example, and others may be strangled by plastic six-pack rings. You can see some of the trash that routinely washes up on coastlines in Figure 25.7. There are five massive garbage patches floating on the Pacific Ocean. Watch this video to learn more about them:  . MEDIA Click image to the left or use the URL below. URL: "
Ocean acidification can kill corals and some shellfish.,(A) true (B) false,A,"Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic. Burning fossil fuels has led to an increase in carbon dioxide in the atmosphere. This carbon dioxide is then absorbed by the oceans, which lowers the pH of the water. Ocean acidification can kill corals and shellfish. It may also cause marine organisms to reproduce less, which could harm other organisms in the food chain. As a result, there also may be fewer marine organisms for humans to consume. "
An example of nonpoint-source pollution is the release of pollution into water through a pipe from a,(A) true (B) false,B,"Pollution that enters water at just one point is called point source pollution. For example, chemicals from a factory might empty into a stream through a pipe or set of pipes (see Figure 21.9). Pollution that enters in many places is called non-point source pollution. This means that the pollution is from multiple sources. With non-point source pollution, runoff may carry the pollution into a body of water. Which type of pollution do you think is harder to control? "
Symptoms of waterborne diseases usually include diarrhea.,(A) true (B) false,A,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
"The total number of people on Earth who lack adequate clean, fresh water is about a million.",(A) true (B) false,B,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
"What percent of Earths water is fresh, liquid water?",(A) 1 percent (B) 10 percent (C) 50 percent (D) 90 percent,A,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
Pollutants in Earths waters include,(A) chemicals (B) sewage (C) heat (D) all of the above,D,"Most ocean pollution comes as runoff from land and originates as agricultural, industrial, and municipal wastes (Figure 1.1). The remaining 20% of water pollution enters the ocean directly from oil spills and people dumping wastes directly into the water. Ships at sea empty their wastes directly into the ocean, for example. Coastal pollution can make coastal water unsafe for humans and wildlife. After rainfall, there can be enough runoff pollution that beaches must be closed to prevent the spread of disease from pollutants. A surprising number of beaches are closed because of possible health hazards each year. A large proportion of the fish we rely on for food live in the coastal wetlands or lay their eggs there. Coastal runoff from farm waste often carries water-borne organisms that cause lesions that kill fish. Humans who come in In some areas of the world, ocean pollution is all too obvious. contact with polluted waters and affected fish can also experience harmful symptoms. More than one-third of the shellfish-growing waters of the United States are adversely affected by coastal pollution. "
"How many people worldwide do not have enough clean, fresh water?",(A) fewer than a hundred (B) about a thousand (C) about a million (D) more than a billion,D,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
The main pollutant added to water by nonpoint-source pollution is,(A) plastic trash (B) pathogens (C) fertilizer (D) none of the above,C,"Water pollution has many causes. One of the biggest causes is fertilizer in runoff. Runoff dissolves fertilizer as it flows over farm fields, lawns, and golf courses. It carries the dissolved fertilizer into bodies of water. More dissolved fertilizer may enter a body of water at the mouth of a river, but there is generally no single point where this type of pollution enters the water. Thats why this type of water pollution is called nonpoint-source pollution. "
Water becomes hypoxic when algae in an algal bloom,(A) undergo cellular respiration (B) carry out photosynthesis (C) grow and reproduce (D) die and decompose,D,"Eventually, the algae in an algal bloom die and decompose. Their decomposition uses up oxygen in the water so that the water becomes hypoxic (without oxygen). This has occurred in many bodies of fresh water and large areas of the ocean, creating dead zones. Dead zones are areas where the hypoxic water cant support life. A very large dead zone exists in the Gulf of Mexico (see Figure 25.6). Nutrients carried into the Gulf by the Mississippi River caused this dead zone. Cutting down on the use of chemical fertilizers is one way to prevent dead zones in bodies of water. Preserving wetlands is also important. Wetlands are habitats such as swamps, marshes, and bogs where the ground is soggy or covered with water much of the year. Wetlands slow down and filter runoff before it reaches bodies of water. Wetlands also provide breeding grounds for many different species of organisms. "
Why are wetlands important for the environment?,(A) They filter runoff before it reaches bodies of water (B) They provide breeding grounds for many different species (C) They can be filled in with soil so more native plants will grow (D) two of the above,D,"People used to think that wetlands were useless. Many wetlands were filled in with rocks and soil to create lands that were then developed with roads, golf courses, and buildings. Now we know that wetlands are very important. Laws have been passed to help protect them. Why are wetlands so important? Wetlands have great biodiversity. They provide homes or breeding sites to a huge variety of species. Because so much wetland area has been lost, many of these species are endangered. Wetlands purify water. They filter sediments and toxins from runoff before it enters rivers, lakes, and oceans. Wetlands slow rushing water. During hurricanes and other extreme weather, wetlands reduce the risk of floods. Although the rate has slowed, wetlands are still being destroyed today. "
Which statement about point-source pollution is false?,(A) It may enter the water from a factory (B) It may include thermal pollution (C) It may come from a sewage treatment plant (D) It enters a body of water in runoff,D,"Unlike runoff, which enters bodies of water everywhere, some sources of pollution enter the water at a single point. This type of water pollution is called point-source pollution. "
"Less than half of Earths water is in the ocean, glaciers, and ice caps.",(A) true (B) false,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
Algal blooms are due to excess nutrients polluting bodies of water.,(A) true (B) false,A,"When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. You can see one in Figure 25.5. The algae out-compete other water organisms. They may make the water unfit for human consumption or recreation. "
There is a very large dead zone in the Gulf of Mexico.,(A) true (B) false,A,"The economic and environmental impact of this spill will be felt for many years. Many people rely on the Gulf for their livelihoods or for recreation. Commercial fishing, tourism, and oil-related jobs are the economic engines of the region. Fearing contamination, NOAA imposed a fishing ban on approximately one-third of the Gulf (Figure 1.5). Tourism is down in the region as beach goers find other ways to spend their time. Real estate prices along the Gulf have declined precipitously. This was the extent of the banned area on June 21, 2010. The Gulf of Mexico is one of only two places in the world where bluefin tuna spawn and they are also already endangered. Marine mammals in the Gulf may come up into the slick as they come to the surface to breathe. Eight national parks and seashores are found along the Gulf shores. Other locations may be ecologically sensitive habitats such as mangroves or marshlands. "
Examples of wetlands include marshes and bogs.,(A) true (B) false,A,"Not all wetlands are alike, as you can see from Figure 13.9. Wetlands vary in how wet they are and how much of the year they are soaked. Wetlands also vary in the kinds of plants that live in them. This depends mostly on the climate where the wetland is found. Types of wetlands include marshes, swamps, and bogs. A marsh is a wetland that is usually under water. It has grassy plants, such as cattails. A swamp is a wetland that may or may not be covered with water but is always soggy. It has shrubs or trees. A bog is a wetland that has soggy soil. It is generally covered with mosses. "
Waterborne diseases are caused by pathogens in drinking water.,(A) true (B) false,A,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
Virtually all thermal pollution of Earths water is caused by global warming.,(A) true (B) false,B,"If heated water is released into a body of water, it may cause thermal pollution. Thermal pollution is a reduction in the quality of water because of an increase in water temperature. A common cause of thermal pollution is the use of water as a coolant by power plants and factories. This water is heated and then returned to the natural environment at a higher temperature. Warm water cant hold as much dissolved oxygen as cool water, so an increase in the temperature of water decreases the amount of oxygen it contains. Fish and other organisms adapted to a particular temperature range and oxygen concentration may be killed by the change in water temperature. "
The ocean is so huge that it can never become seriously polluted.,(A) true (B) false,B,The oceans are vast. You might think they are too big to be harmed by pollution. But thats not the case. Ocean water is becoming seriously polluted. 
All of the following are considered to be renewable resources except,(A) sunlight (B) plants (C) iron (D) soil,D,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
All natural resources are used for energy.,(A) true (B) false,B,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
Some minerals are renewable resources.,(A) true (B) false,A,"Renewable resources are natural resources that are remade by natural processes as quickly as people use them. Examples of renewable resources include sunlight and wind. They are in no danger of being used up. Metals and some other minerals are considered renewable as well because they are not destroyed when they are used. Instead, they can be recycled and used over and over again. Living things are also renewable resources. They can reproduce to replace themselves. However, living things can be over-used or misused to the point of extinction. For example, over-fishing has caused some of the best fishing spots in the ocean to be nearly depleted, threatening entire fish species with extinction. To be truly renewable, living things must be used wisely. They must be used in a way that meets the needs of the present generation but also preserves them for future generations. Using resources in this way is called sustainable use. "
Nonrenewable resources include,(A) uranium (B) aluminum (C) organisms (D) two of the above,A,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
"If natural gas continues to be used at current rates, it will be used up in a few",(A) months (B) years (C) decades (D) centuries,C,"Natural gas, often known simply as gas, is composed mostly of the hydrocarbon methane. The amount of natural gas being extracted and used in the Untied States is increasing rapidly. "
It takes millions of years for fossil fuels to form.,(A) true (B) false,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
"At current rates of use, oil will be used up in just a few decades.",(A) true (B) false,A,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
How long does it usually take soil to form?,(A) about a year (B) a few hundred years (C) a couple of thousand years (D) millions of years,D,"Soil formation requires weathering. Where there is less weathering, soils are thinner. However, soluble minerals may be present. Where there is intense weathering, soils may be thick. Minerals and nutrients would have been washed out. Soil development takes a very long time. It may take hundreds or even thousands of years to form the fertile upper layer of soil. Soil scientists estimate that in the very best soil forming conditions, soil forms at a rate of about 1mm/year. In poor conditions, it may take thousands of years! How well soil forms and what type of soil forms depends on many factors. These include climate, the original rock type, the slope, the amount of time, and biological activity. "
The use of nuclear power adds greenhouse gases to the atmosphere.,(A) true (B) false,B,"Nuclear power is clean. It does not pollute the air. However, the use of nuclear energy does create other environ- mental problems. Uranium must be mined (Figure 1.3). The process of splitting atoms creates radioactive waste, which remains dangerous for thousands or hundreds of thousands of years. As yet, there is no long-term solution for storing this waste. The development of nuclear power plants has been on hold for three decades. Accidents at Three Mile Island and Chernobyl, Ukraine verified peoples worst fears about the dangers of harnessing nuclear power (Figure 1.4). Recently, nuclear power appeared to be making a comeback as society looked for alternatives to fossil fuels. After all, nuclear power emits no pollutants, including no greenhouse gases. But the 2011 disaster at the Fukushima Daiichi Nuclear Power Plant in Japan may have resulted in a new fear of nuclear power. The cause of the disaster was a 9.0 magnitude earthquake and subsequent tsunami, which compromised the plant. Although a total meltdown was averted, the plant experienced multiple partial meltdowns, core breaches, radiation releases, and cooling failures. The plant is scheduled for a complete cold shutdown before the end of 2011. Damaged building near the site of the Chernobyl disaster. Nuclear power is a controversial subject in California and most other places. Nuclear power has no pollutants including carbon emissions, but power plants are not always safe and the long-term disposal of wastes is a problem that has not yet been solved. The future of nuclear power is murky. "
About what percent of energy used worldwide comes from nonrenewable resources?,(A) 2025 percent (B) 4045 percent (C) 6065 percent (D) 8085 percent,D,"Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the uranium needed for nuclear power will soon be used up if we continue to consume them at these rates. Using fossil fuels and nuclear energy creates other problems as well. The burning of fossil fuels releases carbon dioxide into the atmosphere. This is one of the major greenhouse gases causing global climate change. Nuclear power creates another set of problems, including the disposal of radioactive waste. "
Decomposition of garbage releases methane gas that can be used for fuel.,(A) true (B) false,A,"Bacteria known as decomposers break down wastes and dead organisms into smaller molecules. These bacteria use the organic substrates they break down to get their energy, carbon, and nutrients they need for survival. "
LED light bulbs use less energy than incandescent light bulbs.,(A) true (B) false,A,"LED stands for light-emitting diode. An LED light contains a material called a semi-conductor, which gives off visible light when an electric current flows through it. LED lights are used for traffic lights (see Figure 1.5) and also indicator lights on computers, cars, and many other devices. This type of light is very reliable and durable. Q: Some light bulbs produce a lot of heat in addition to visible light, so they waste energy. Other bulbs produce much less heat, so they use energy more efficiently. Which light bulbs described above would you place in each category? A: Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. The other light bulbs produce light by some type of luminescence, in which light is produced without heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use? "
__energy provided by burning or decomposing organic matter,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,C,"Bacteria known as decomposers break down wastes and dead organisms into smaller molecules. These bacteria use the organic substrates they break down to get their energy, carbon, and nutrients they need for survival. "
__resource that cannot be remade at all or as quickly as people use it,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,G,"From the table in the concept ""Materials Humans Use,"" you can see that many of the resources we depend on are non-renewable. Non-renewable resources vary in their availability; some are very abundant and others are rare. Materials, such as gravel or sand, are technically non-renewable, but they are so abundant that running out is no issue. Some resources are truly limited in quantity: when they are gone, they are gone, and something must be found that will replace them. There are even resources, such as diamonds and rubies, that are valuable in part because they are so rare. "
__use of resources in a way that meets current needs and also the needs of future generations,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,E,"Is it possible for all the worlds people to live well and still protect the planet? Thats the aim of sustainable development. Its goals are to: 1. Distribute resources fairly. 2. Conserve resources so they wont run out. 3. Use resources in ways that wont harm ecosystems. A smaller human population may be part of the solution. Better use of resources is another part. For example, when forests are logged, new trees should be planted. Everyone can help in the effort. What will you do? "
"__coal, oil, or natural gas",(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,F,Natural gas is often found along with coal or oil in underground deposits. This is because natural gas forms with these other fossil fuels. One difference between natural gas and oil is that natural gas forms at higher temperatures. 
The use of biomass energy does not contribute to air pollution.,(A) true (B) false,B,"Fossil fuels are ancient plants and animals that have been converted into usable hydrocarbons. Burning plant and animal material directly also produces pollutants. Biomass is the total amount of living material found in an environment. The biomass of a rainforest is the amount of living material found in that rainforest. The primary way biomass is burned is for slash-and-burn agriculture (Figure 1.2). The rainforest is slashed down and then the waste is burned to clear the land for farming. Biomass from other biomes, such as the savannah, is also burned to clear farmland. The pollutants are much the same as from burning fossil fuels: CO2 , carbon monoxide, methane, particulates, nitrous oxide, hydrocarbons, and organic and elemental carbon. Burning forests increases greenhouse gases in the atmosphere by releasing the CO2 stored in the biomass and also by removing the forest so that it cannot store CO2 in the future. As with all forms of air pollution, the smoke from biomass burning often spreads far and pollutants can plague neighboring states or countries. Particulates result when anything is burned. About 40% of the particulates that enter the atmosphere above the United States are from industry and about 17% are from vehicles. Particulates also occur naturally from volcanic eruptions or windblown dust. Like other pollutants, they travel all around the world on atmospheric currents. "
Fossil fuels form from organic remains that become buried under the ground.,(A) true (B) false,A,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
__anything supplied by nature that helps support life,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,B,"Abiotic factors are the nonliving parts of ecosystems. They include air, sunlight, soil, water, and minerals. These are all things that are needed for life. They determine which living things  and how many of them  an ecosystem can support. Figure 18.2 shows an ecosystem and its abiotic factors. "
Recycling is the best way to conserve natural resources.,(A) true (B) false,B,"Especially when it comes to nonrenewable resources, conserving natural resources is important. Using less of them means that they will last longer. It also means they will impact the environment less. Everyone can help make a difference. There are three basic ways that all of us can conserve natural resources. They are referred to as the three Rs: reduce, reuse, and recycle. "
__nonrenewable resource that plants need to grow,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,A,"Nonrenewable resources are natural resources that cant be remade or else take too long to remake to keep up with human use. Examples of nonrenewable resources are coal, oil, and natural gas, all of which are fossil fuels. Fossil fuels form from the remains of plants and animals over hundreds of millions of years. We are using them up far faster than they can be replaced. At current rates of use, oil and natural gas will be used up in just a few decades, and coal will be used up in a couple of centuries. Uranium is another nonrenewable resource. It is used to produce nuclear power. Uranium is a naturally occurring chemical element that cant be remade. It will run out sooner or later if nuclear energy continues to be used. Soil is a very important natural resource. Plants need soil to grow, and plants are the basis of terrestrial ecosystems. Theoretically, soil can be remade. However, it takes millions of years for soil to form, so from a human point of view, it is a nonrenewable resource. Soil can be misused and eroded (see Figure 25.9). It must be used wisely to preserve it for the future. This means taking steps to avoid soil erosion and contamination of soil by toxins such as oil spills. "
__resource that is remade by natural processes as quickly as people use it,(A) asoil (B) bnatural resource (C) cbiomass energy (D) drenewable resource (E) esustainable use (F) ffossil fuel (G) gnonrenewable resource,D,"A resource is renewable if it is remade by natural processes at the same rate that humans use it up. Sunlight and wind are renewable resources because they will not be used up ( Figure 1.1). The rising and falling of ocean tides is another example of a resource in unlimited supply. A sustainable resource is a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs. People can sustainably harvest wood, cork, and bamboo. Farmers can also grow crops sustainably by not planting the same crop in their soil year after year. Planting the same crop each year can remove nutrients from the soil. This means that wood, cork, bamboo, and crops can be sustainable resources. "
Kitchen and garden wastes can be recycled by composting them.,(A) true (B) false,A,"If an item can no longer be used or reused, try to recycle it. Recycling means taking a used item, breaking it down, and reusing the components. It generally takes less energy to recycle materials than obtain new ones. Recycling also keeps waste out of landfills. Some of the items that can be recycled include: glass, paper, cardboard, plastic, aluminum, iron, steel, batteries, electronics, tires, and concrete. You can learn how some of these materials are recycled by watching this video:  . MEDIA Click image to the left or use the URL below. URL:  Even kitchen scraps and garden wastes can be recycled. They can be tossed into a compost bin, like the one in Figure 25.13. The recycled compost gradually breaks down to form rich humus that can be added to lawns and gardens to improve the soil. Encourage your family to recycle if they dont already. Even if you dont have curbside recycling where you live, there are likely to be recycling drop boxes or centers available for recycling many items. If you have recycling bins at school, be sure to use them. If not, raise the issue with your teacher or principal. You can also write a letter to the editor of your local newspaper encouraging everyone in your community to recycle. "
Methane gas produced by decomposing garbage is a fossil fuel.,(A) true (B) false,B,Natural gas is mostly methane. 
Which energy resource is used more than any other in the world?,(A) wood (B) wind (C) sun (D) oil,D,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
Renewable resources include,(A) living things (B) uranium (C) coal (D) two of the above,D,"Renewable energy resources include solar, water, wind, biomass, and geothermal power. These resources are usually replaced at the same rate that we use them. Scientists know that the Sun will continue to shine for billions of years. So we can use the solar energy without it ever running out. Water flows from high places to lower ones. Wind blows from areas of high pressure to areas of low pressure. We can use the flow of wind and water to generate power. We can count on wind and water to continue to flow! Burning wood is an example of biomass energy. Changing grains into biofuels is biomass energy. Biomass is renewable because we can plant new trees or crops to replace the ones we use. Geothermal energy uses water that was heated by hot rocks. There are always more hot rocks available to heat more water. Even renewable resources can be used unsustainably. We can cut down too many trees without replanting. We might need grains for food rather than biofuels. Some renewable resources are too expensive to be widely used. As the technology improves and more people use renewable energy, the prices will come down. The cost of renewable resources will go down relative to fossil fuels as we use fossil fuels up. In the long run renewable resources will need to make up a large amount of what we use. "
Nonrenewable energy resources include,(A) natural gas (B) nuclear energy (C) biomass energy (D) two of the above,D,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
Renewable energy resources include,(A) sunlight (B) wind (C) living things (D) all of the above,D,"Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table 17.1. Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. here? Renewable Energy Resource Sunlight The energy in sunlight, or solar energy, can be used to heat homes. It can also be used to produce electricity in solar cells. However, solar energy may not be practical in areas that are often cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water When water falls downhill, its potential energy is con- verted to kinetic energy that can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream and reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air, so it has kinetic energy that can do work. Remember the wind turbines that opened this chapter? Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy and unattractive in the landscape. Water flowing through Hoover dam between Arizona and Nevada generates electricity for both of these states and also by southern California. The dam spans the Colorado River. This old-fashioned windmill captures wind energy that is used for pumping water out of a well. Windmills like this one have been used for centuries. Renewable Energy Resource Biomass The stored chemical energy of trees and other plants is called biomass energy. When plant materials are burned, they produce thermal energy that can be used for heating, cooking, or generating electricity. Biomassespecially woodis an important energy source in countries where most people cant afford fossil fuels. Some plants can also be used to make ethanol, a fuel that is added to gasoline. Ethanol produces less pollution than gasoline, but large areas of land are needed to grow the plants needed to make it. Geothermal Heat below Earths surfacecalled geothermal en- ergycan be used to produce electricity. A power plant pumps water underground where it is heated. Then it pumps the water back to the plant and uses its thermal energy to generate electricity. On a small scale, geothermal energy can be used to heat homes. Installing a geothermal system can be very costly, how- ever, because of the need to drill through underground rocks. Example This large machine is harvesting and grinding plants to be used for biomass energy. This geothermal power plant is located in Italy where hot magma is close to the surface. "
The method of conserving resources that uses the least energy is,(A) reducing resource use (B) reusing resources (C) recycling resources (D) refining resources,A,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
Soil is a nonrenewable natural resource because it,(A) can never be renewed (B) takes so long to form (C) is not needed in nature (D) does not produce energy,B,"Nonrenewable resources are natural resources that cant be remade or else take too long to remake to keep up with human use. Examples of nonrenewable resources are coal, oil, and natural gas, all of which are fossil fuels. Fossil fuels form from the remains of plants and animals over hundreds of millions of years. We are using them up far faster than they can be replaced. At current rates of use, oil and natural gas will be used up in just a few decades, and coal will be used up in a couple of centuries. Uranium is another nonrenewable resource. It is used to produce nuclear power. Uranium is a naturally occurring chemical element that cant be remade. It will run out sooner or later if nuclear energy continues to be used. Soil is a very important natural resource. Plants need soil to grow, and plants are the basis of terrestrial ecosystems. Theoretically, soil can be remade. However, it takes millions of years for soil to form, so from a human point of view, it is a nonrenewable resource. Soil can be misused and eroded (see Figure 25.9). It must be used wisely to preserve it for the future. This means taking steps to avoid soil erosion and contamination of soil by toxins such as oil spills. "
Energy resources that do not create air pollution when they are used include,(A) solar energy (B) biomass energy (C) natural gas (D) two of the above,A,"How can air pollution be reduced? Using less fossil fuel is one way to lessen pollution. Some examples of ways to conserve fossil fuels are: Riding a bike or walking instead of driving. Taking a bus or carpooling. Buying a car that has greater fuel efficiency. Turning off lights and appliances when they are not in use. Using energy efficient light bulbs and appliances. Buying fewer things that are manufactured using fossil fuels. All these actions reduce the amount of energy that power plants need to produce. Click image to the left or use the URL below. URL:  Developing alternative energy sources is important. What are some of the problems facing wider adoption of alternative energy sources? The technologies for several sources of alternative energy, including solar and wind, are still being developed. Solar and wind are still expensive relative to using fossil fuels. The technology needs to advance so that the price falls. Some areas get low amounts of sunlight and are not suited for solar. Others do not have much wind. It is important that regions develop what best suits them. While the desert Southwest will need to develop solar, the Great Plains can use wind energy as its energy source. Perhaps some locations will rely on nuclear power plants, although current nuclear power plants have major problems with safety and waste disposal. Sometimes technological approaches are what is needed. Click image to the left or use the URL below. URL: "
Raw materials needed for photosynthesis include,(A) water (B) sugar (C) carbon dioxide (D) two of the above,D,"In plants, most chloroplasts are found in the leaves. Therefore, all the raw materials needed for photosynthesis must be present in the leaves. These materials include light, water, and carbon dioxide. The shape of the leaves gives them a lot of surface area to absorb light for photosynthesis. Roots take up water from the soil. Stems carry the water from the roots to the leaves. Carbon dioxide enters the leaves through tiny openings called stomata. (The oxygen released during photosynthesis also exits the leaves through the stomata.) "
"In plants, most chloroplasts are found in the",(A) fruits (B) stems (C) roots (D) leaves,D,"In plants and algae, photosynthesis takes place in chloroplasts. (Photosynthetic bacteria have other structures for this purpose.) A chloroplast is a type of plastid, or plant organelle. It contains the green pigment known as chlorophyll. The presence of chloroplasts in plant cells is one of the major ways they differ from animal cells. You can see chloroplasts in plant cells Figure 4.8. "
The first stage of photosynthesis takes place inside structures called,(A) stroma (B) stomata (C) thylakoids (D) none of the above,C,"Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced. Chloroplasts contain stacks of thylakoids, which are flattened sacs of membrane. Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids ( Figure 1.1). The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. The chloroplast is the photosynthesis fac- tory of the plant. "
During the Calvin cycle,(A) chlorophyll absorbs light (B) energy is stored in NADPH (C) ATP forms from ADP (D) none of the above,D,"The Calvin cycle occurs in the second stage of photosynthesis. This stage takes place in the stroma of the chloroplast. In the Calvin cycle, carbon dioxide is used to produce glucose (sugar) using the energy stored in ATP and NADPH. The energy is released from these molecules when ATP loses phosphate (Pi ) to become ADP and NADPH loses hydrogen (H) to become NADP+ . "
The light reactions of photosynthesis produce,(A) glucose (B) oxygen (C) water (D) NADP+,B,"The light reactions occur in the first stage of photosynthesis. This stage takes place in the thylakoid membranes of the chloroplast. In the light reactions, energy from sunlight is absorbed by chlorophyll. This energy is temporarily transferred to two molecules: ATP and NADPH. These molecules are used to store the energy for the second stage of photosynthesis. The light reactions use water and produce oxygen. "
_______Only heterotrophs need food for energy.,(A) true (B) false,B,"Consumers are organisms that depend on other living things for food. They take in organic compounds by eating or absorbing other living things. Consumers include all animals and fungi. They also include some bacteria and protists. Consumers are also called heterotrophs. There are several different types of heterotrophs depending on exactly what they consume. They may be herbivores, carnivores, or omnivores. Herbivores are heterotrophs that consume producers such as plants or algae. Examples include rabbits and snails. Carnivores are heterotrophs that consume animals. Examples include lions and frogs. Omnivores are heterotrophs that consume both plants and animals. They include crows and human beings. The grizzly bears pictured in Figure 24.2 are also omnivores. "
_______ATP is the concentrated form of energy that is carried by the blood and taken up by cells.,(A) true (B) false,B,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
_______Producing one molecule of glucose requires six molecules of water.,(A) true (B) false,A,"What is the source of glucose for living things? It is made by plants and certain other organisms. The process in which glucose is made using energy in light is photosynthesis. This process requires carbon dioxide and water. It produces oxygen in addition to glucose. Photosynthesis consists of many chemical reactions. Overall, the reactions of photosynthesis can be summed up by this chemical equation: 6CO2 + 6H2 O + light energy ! C6 H12 O6 + 6O2 In words, this means that six molecules of carbon dioxide (CO2 ) combine with six molecules of water (H2 O) in the presence of light energy. This produces one molecule of glucose (C6 H12 O6 ) and six molecules of oxygen (O2 ). Use this interactive animation to learn more about photosynthesis: Click on this link for a song about photosynthesis to reinforce the basic ideas:  MEDIA Click image to the left or use the URL below. URL: "
_______Some protists can carry out photosynthesis.,(A) true (B) false,A,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
All living things need chemical energy for life processes.,(A) true (B) false,A,"All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ecosystems. "
The chemical formula for glucose is C6H12O6.,(A) true (B) false,A,"Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. "
_______Thylakoids are stacks of flattened sacs in a chloroplast.,(A) true (B) false,A,"The structure of a chloroplast is shown in Figure 4.9. The chloroplast is surrounded by two membranes. Inside the chloroplast are stacks of flattened sacs of membrane, called thylakoids. The thylakoids contain chlorophyll. Surrounding the thylakoids is a space called the stroma. The stroma is filled with watery (""aqueous"") fluid. "
Organisms that make food for themselves and other living things are called heterotrophs.,(A) true (B) false,B,"The organisms that produce food are extremely important in every ecosystem. Organisms that produce their own food are called producers. There are two ways of producing food energy: Photosynthesis: plants on land, phytoplankton in the surface ocean, and some other organisms. Chemosynthesis: bacteria at hydrothermal vents. Organisms that use the food energy that was created by producers are named consumers. There are many types of consumers: Herbivores eat producers directly. These animals break down the plant structures to get the materials and energy they need. Carnivores eat animals; they can eat herbivores or other carnivores. Omnivores eat plants and animals as well as fungi, bacteria, and organisms from the other kingdoms. "
_______All photosynthesis takes place in chloroplasts.,(A) true (B) false,B,"In plants and algae, photosynthesis takes place in chloroplasts. (Photosynthetic bacteria have other structures for this purpose.) A chloroplast is a type of plastid, or plant organelle. It contains the green pigment known as chlorophyll. The presence of chloroplasts in plant cells is one of the major ways they differ from animal cells. You can see chloroplasts in plant cells Figure 4.8. "
_______Each chloroplast is surrounded by two membranes.,(A) true (B) false,A,"The structure of a chloroplast is shown in Figure 4.9. The chloroplast is surrounded by two membranes. Inside the chloroplast are stacks of flattened sacs of membrane, called thylakoids. The thylakoids contain chlorophyll. Surrounding the thylakoids is a space called the stroma. The stroma is filled with watery (""aqueous"") fluid. "
The role of chlorophyll in photosynthesis is providing carbon for glucose.,(A) true (B) false,B,"In plants, most chloroplasts are found in the leaves. Therefore, all the raw materials needed for photosynthesis must be present in the leaves. These materials include light, water, and carbon dioxide. The shape of the leaves gives them a lot of surface area to absorb light for photosynthesis. Roots take up water from the soil. Stems carry the water from the roots to the leaves. Carbon dioxide enters the leaves through tiny openings called stomata. (The oxygen released during photosynthesis also exits the leaves through the stomata.) "
The second stage of photosynthesis takes place in the cytoplasm.,(A) true (B) false,B,"The Calvin cycle occurs in the second stage of photosynthesis. This stage takes place in the stroma of the chloroplast. In the Calvin cycle, carbon dioxide is used to produce glucose (sugar) using the energy stored in ATP and NADPH. The energy is released from these molecules when ATP loses phosphate (Pi ) to become ADP and NADPH loses hydrogen (H) to become NADP+ . "
_______any organism that uses energy to make glucose,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,F,"Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs (""self feeders""). All other living things obtain glucose by eating autotrophs (or organisms that eat autotrophs). These living things are called heterotrophs (""other feeders""). "
_______second stage of photosynthesis,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,C,"The second stage of photosynthesis is the production of glucose from carbon dioxide. This process occurs in a continuous cycle, named after its discover, Melvin Calvin. The Calvin cycle uses CO2 and the energy temporarily stored in ATP and NADPH to make the sugar glucose. "
_______form of energy needed to fuel life processes in all living things,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,G,"All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ecosystems. "
_______plant organelle where photosynthesis takes place,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,E,"Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced. Chloroplasts contain stacks of thylakoids, which are flattened sacs of membrane. Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids ( Figure 1.1). The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. The chloroplast is the photosynthesis fac- tory of the plant. "
_______form of energy needed for photosynthesis,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,D,Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy ! C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose is used for energy by the cells of almost all living things. Plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). How do living things get energy from glucose? The answer is cellular respiration. 
_______any organism that obtains energy from other living things,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,B,"Living things can be classified based on how they obtain energy. Some use the energy in sunlight or chemical compounds directly to make food. Some get energy indirectly by consuming other organisms, either living or dead. "
_______first stage of photosynthesis,(A) alight reactions (B) bheterotroph (C) cCalvin cycle (D) dlight (E) echloroplast (F) fautotroph (G) gchemical,A,"The second stage of photosynthesis is the production of glucose from carbon dioxide. This process occurs in a continuous cycle, named after its discover, Melvin Calvin. The Calvin cycle uses CO2 and the energy temporarily stored in ATP and NADPH to make the sugar glucose. "
The chemical formula for glucose is,(A) C6 H12 O6  (B) C12 H6 O12  (C) C6 H6 O12  (D) none of the above,A,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
"In the reactions of photosynthesis, how many molecules of carbon dioxide are needed to produce one molecule of glucose?",(A) one (B) six (C) nine (D) twelve,B,"The overall chemical reaction for photosynthesis is 6 molecules of carbon dioxide (CO2 ) and 6 molecules of water (H2 O), with the addition of solar energy. This produces 1 molecule of glucose (C6 H12 O6 ) and 6 molecules of oxygen Stomata are special pores that allow gasses to enter and exit the leaf. (O2 ). Using chemical symbols, the equation is represented as follows: 6CO2 + 6H2 O  C6 H12 O6 + 6O2 . Though this equation may not seem that complicated, photosynthesis is a series of chemical reactions divided into two stages, the light reactions and the Calvin cycle ( Figure 1.3). "
Types of organisms that carry out photosynthesis include,(A) bacteria (B) algae (C) plants (D) all of the above,D,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
The function of thylakoids is to,(A) capture light energy (B) produce glucose molecules (C) release energy from ATP and NADPH (D) all of the above,A,"Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced. Chloroplasts contain stacks of thylakoids, which are flattened sacs of membrane. Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids ( Figure 1.1). The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. The chloroplast is the photosynthesis fac- tory of the plant. "
The first stage of photosynthesis requires,(A) carbon dioxide (B) water (C) oxygen (D) none of the above,B,"Photosynthesis begins with the light reactions. It is during these reactions that the energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membranes of the chloroplast. The energy is then temporarily transferred to two molecules, ATP and NADPH, which are used in the second stage of photosynthesis. ATP and NADPH are generated by two electron transport chains. During the light reactions, water is used and oxygen is produced. These reactions can only occur during daylight as the process needs sunlight to begin. "
The second stage of photosynthesis requires,(A) light (B) oxygen (C) water (D) carbon dioxide,D,"The second stage of photosynthesis is the production of glucose from carbon dioxide. This process occurs in a continuous cycle, named after its discover, Melvin Calvin. The Calvin cycle uses CO2 and the energy temporarily stored in ATP and NADPH to make the sugar glucose. "
What is the function of stomata in plant leaves?,(A) They let leaves exchange gases with the air (B) They absorb light from the sun (C) They allow water to enter the leaves (D) none of the above,A,"Leaves are the keys not only to plant life but to virtually all life on land. The primary role of leaves is to collect sunlight and make food by photosynthesis. Leaves vary in size, shape, and how they are arranged on stems. You can see examples of different types of leaves in Figure 10.6. Each type of leaf is well suited for the plants environment. It maximizes light exposure while conserving water, reducing wind resistance, or benefiting the plant in some other way in its particular habitat. For example, some leaves are divided into many smaller leaflets. This reduces wind resistance and water loss. Leaves are basically factories for photosynthesis. A factory has specialized machines to produce a product. In a leaf, the ""machines"" are the chloroplasts. A factory is connected to a transportation system that supplies it with raw materials and carries away the finished product. In a leaf, transport is carried out by veins containing vascular tissue. Veins carry water and minerals to the cells of leaves. They carry away dissolved sugar. A factory has bricks, siding, or other external protection. A leaf is covered with dermal cells. They secrete waxy cuticle to prevent evaporation of water from the leaf. A factory has doors and windows to let some materials enter and leave. The surface of the leaf has tiny pores called stomata (stoma, singular). They can open and close to control the movement of gases between the leaves and the air. You can see a close-up of a stoma in Figure 10.7. "
Products of cellular respiration include,(A) oxygen (B) water (C) ADP (D) two of the above,B,"What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be converted to a net total of 36 or 38 molecules of ATP. This only occurs in the presence of oxygen. "
"For each glucose molecule that undergoes cellular respiration, what is the maximum number of ATP molecules that are produced?",(A) 2 (B) 4 (C) 34 (D) 38,D,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
"During cellular respiration, each ATP molecule forms when a phosphate is added to",(A) alcohol (B) glucose (C) pyruvate (D) ADP,D,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
"In the first stage of cellular respiration, enzymes split a glucose molecule into two smaller molecules of",(A) ADP (B) oxygen (C) pyruvate (D) carbon dioxide,C,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
Cellular respiration occurs in,(A) plants (B) protists (C) animals (D) all of the above,D,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
Which stage of cellular respiration is anaerobic?,(A) glycolysis (B) electron transport (C) Krebs cycle (D) none of the above,A,"The pyruvate molecules from glycolysis next enter the matrix of a mitochondrion. Thats where the second stage of cellular respiration takes place. This stage is called the Krebs cycle. During this stage, two more molecules of ATP are produced. Other energy-storing molecules are also produced (to be used to make more ATP in stage 3). The Krebs cycle requires oxygen. Anything that needs oxygen is described as aerobic. The oxygen combines with the carbon from the pyruvate molecules. This forms carbon dioxide, a waste product. "
The stage of cellular respiration that also occurs in fermentation is,(A) glycolysis (B) electron transport (C) Krebs cycle (D) none of the above,A,"Some organisms can produce ATP from glucose anaerobically. One way this happens is called fermentation. Fermentation includes the glycolysis step of cellular respiration. However, it doesnt include the other, aerobic steps. There are two types of fermentation: lactic acid fermentation and alcoholic fermentation. "
How many molecules of ATP are produced during the Krebs cycle?,(A) one (B) two (C) three (D) four,B,"The pyruvate molecules from glycolysis next enter the matrix of a mitochondrion. Thats where the second stage of cellular respiration takes place. This stage is called the Krebs cycle. During this stage, two more molecules of ATP are produced. Other energy-storing molecules are also produced (to be used to make more ATP in stage 3). The Krebs cycle requires oxygen. Anything that needs oxygen is described as aerobic. The oxygen combines with the carbon from the pyruvate molecules. This forms carbon dioxide, a waste product. "
"When your muscle cells are working too hard for cellular respiration to keep them supplied with energy, they start producing ATP by",(A) lactic acid fermentation (B) alcoholic fermentation (C) aerobic respiration (D) aerobic fermentation,A,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
The matrix of a mitochondrion is the site of,(A) glycolysis (B) the Krebs cycle (C) alcoholic fermentation (D) lactic acid fermentation,B,"The mitochondrion (mitochondria, plural) is an organelle that makes energy available to the cell. Its like the power plant of a cell. It uses energy in glucose to make smaller molecules called ATP (adenosine triphosphate). ATP packages energy in smaller amounts that cells can use. Think about buying a bottle of water from a vending machine. The machine takes only quarters, and you have only dollar bills. The dollar bills wont work in the vending machine. Glucose is like a dollar bill. It contains too much energy for cells to use. ATP is like a quarter. It contains just the right amount of energy for use by cells. "
Molecules that form during glycolysis include,(A) pyruvate (B) carbon dioxide (C) ATP (D) two of the above,D,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
Which waste product is produced during the Krebs cycle?,(A) water (B) alcohol (C) carbon dioxide (D) lactic acid,C,"The pyruvate molecules from glycolysis next enter the matrix of a mitochondrion. Thats where the second stage of cellular respiration takes place. This stage is called the Krebs cycle. During this stage, two more molecules of ATP are produced. Other energy-storing molecules are also produced (to be used to make more ATP in stage 3). The Krebs cycle requires oxygen. Anything that needs oxygen is described as aerobic. The oxygen combines with the carbon from the pyruvate molecules. This forms carbon dioxide, a waste product. "
_______Cellular respiration uses oxygen in addition to glucose.,(A) true (B) false,A,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
_______Cellular respiration takes place in the cells of all aerobic organisms.,(A) true (B) false,A,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
_______Glycolysis takes place in the matrix of a mitochondrion.,(A) true (B) false,B,"Glycolysis is the first stage of cellular respiration. It takes place in the cytoplasm of the cell. The world glycolysis means ""glucose splitting"". Thats exactly what happens in this stage. Enzymes split a molecule of glucose into two smaller molecules called pyruvate. This results in a net gain of two molecules of ATP. Other energy-storing molecules are also produced. (Their energy will be used in stage 3 to make more ATP.) Glycolysis does not require oxygen. Anything that doesnt need oxygen is described as anaerobic. "
_______The second stage of cellular respiration produces four molecules of ATP.,(A) true (B) false,B,"The third and final stage of cellular respiration is called electron transport. Remember the other energy-storing molecules from glycolysis and the Krebs cycle? Their energy is used in this stage to make many more molecules of ATP. In fact, during this stage, as many as 34 molecules of ATP are produced. Electron transport requires oxygen, so this stage is also aerobic. The oxygen combines with hydrogen from the energy-storing molecules. This forms water, another waste product. "
An ATP molecule forms when a phosphate is added to ADP.,(A) true (B) false,A,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
Cells without mitochondria cannot break down glucose for energy.,(A) true (B) false,B,"The mitochondrion (mitochondria, plural) is an organelle that makes energy available to the cell. Its like the power plant of a cell. It uses energy in glucose to make smaller molecules called ATP (adenosine triphosphate). ATP packages energy in smaller amounts that cells can use. Think about buying a bottle of water from a vending machine. The machine takes only quarters, and you have only dollar bills. The dollar bills wont work in the vending machine. Glucose is like a dollar bill. It contains too much energy for cells to use. ATP is like a quarter. It contains just the right amount of energy for use by cells. "
_______A waste product of electron transport is water.,(A) true (B) false,A,"The third and final stage of cellular respiration is called electron transport. Remember the other energy-storing molecules from glycolysis and the Krebs cycle? Their energy is used in this stage to make many more molecules of ATP. In fact, during this stage, as many as 34 molecules of ATP are produced. Electron transport requires oxygen, so this stage is also aerobic. The oxygen combines with hydrogen from the energy-storing molecules. This forms water, another waste product. "
All three stages of cellular respiration are aerobic.,(A) true (B) false,B,"Cellular respiration occurs in three stages. The flow chart in Figure dont purge me shows the order in which the stages occur and how much ATP forms in each stage. The names of the stages are glycolysis, the Krebs cycle, and electron transport. Each stage is described below. "
_______The products of photosynthesis are the reactants of cellular respiration.,(A) true (B) false,A,"Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Together, these two processes provide energy to almost all of Earths organisms. The two processes are closely related, as you can see in the Figure 1.1. In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use. A: In photosynthesis, carbon dioxide (CO2 ) and water (H2 O) are the reactants. They combine using energy from light to produce oxygen (O2 ) and glucose (C6 H12 O6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy. "
_______Fermentation produces ATP from lactic acid or alcohol.,(A) true (B) false,B,"Sometimes cells need to obtain energy from sugar, but there is no oxygen present to complete cellular respiration. In this situation, cellular respiration can be anaerobic, occurring in the absence of oxygen. In this process, called fermentation, only the first step of respiration, glycolysis, occurs, producing two ATP; no additional ATP is produced. Therefore, the organism only obtains the two ATP molecules per glucose molecule from glycolysis. Compared to the 36-38 ATP produced under aerobic conditions, anaerobic respiration is not a very efficient process. Fermentation allows the first step of cellular respiration to continue and produce some ATP, even without oxygen. Yeast (single-celled eukaryotic organisms) perform alcoholic fermentation in the absence of oxygen. The products of alcoholic fermentation are ethyl alcohol (drinking alcohol) and carbon dioxide gas. This process is used to make common food and drinks. For example, alcoholic fermentation is used to bake bread. The carbon dioxide bubbles allow the bread to rise and become fluffy. Meanwhile, the alcohol evaporates. In wine making, the sugars of grapes are fermented to produce wine. The sugars are the starting materials for glycolysis. Animals and some bacteria and fungi carry out lactic acid fermentation. Lactic acid is a waste product of this process. Our muscles perform lactic acid fermentation during strenuous exercise, since oxygen cannot be delivered to the muscles quickly enough. The buildup of lactic acid is believed to make your muscles sore after exercise. Bacteria that produce lactic acid are used to make cheese and yogurt. The lactic acid causes the proteins in milk to thicken. Lactic acid also causes tooth decay, because bacteria use the sugars in your mouth for energy. Pictured below are some products of fermentation ( Figure 1.1). Products of fermentation include cheese (lactic acid fermentation) and wine (alco- holic fermentation). "
Water forms as a waste product during the second stage of cellular respiration.,(A) true (B) false,B,"The third and final stage of cellular respiration is called electron transport. Remember the other energy-storing molecules from glycolysis and the Krebs cycle? Their energy is used in this stage to make many more molecules of ATP. In fact, during this stage, as many as 34 molecules of ATP are produced. Electron transport requires oxygen, so this stage is also aerobic. The oxygen combines with hydrogen from the energy-storing molecules. This forms water, another waste product. "
The final stage of cellular respiration is called electron transport.,(A) true (B) false,A,"The third and final stage of cellular respiration is called electron transport. Remember the other energy-storing molecules from glycolysis and the Krebs cycle? Their energy is used in this stage to make many more molecules of ATP. In fact, during this stage, as many as 34 molecules of ATP are produced. Electron transport requires oxygen, so this stage is also aerobic. The oxygen combines with hydrogen from the energy-storing molecules. This forms water, another waste product. "
_______second stage of cellular respiration,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,E,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
_______organelle that is called the powerhouse of the cell,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,G,"The mitochondrion (mitochondria, plural) is an organelle that makes energy available to the cell. Its like the power plant of a cell. It uses energy in glucose to make smaller molecules called ATP (adenosine triphosphate). ATP packages energy in smaller amounts that cells can use. Think about buying a bottle of water from a vending machine. The machine takes only quarters, and you have only dollar bills. The dollar bills wont work in the vending machine. Glucose is like a dollar bill. It contains too much energy for cells to use. ATP is like a quarter. It contains just the right amount of energy for use by cells. "
_______process in which cells burn glucose for energy,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,C,"Your own body cells burn fuel in combustion reactions. The fuel is glucose (C6 H12 O6 ), a simple sugar. The process in which combustion of glucose occurs in body cells is called cellular respiration. This combustion reaction provides energy for life processes. Cellular respiration can be summed up by the equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O Where does glucose come from? It is produced by plants during photosynthesis. In this process, carbon dioxide and water combine to form glucose. Which type of chemical reaction is photosynthesis? "
_______process in which yeasts in bread produce ATP from glucose,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,F,"In alcoholic fermentation, glycolysis is followed by a step that produces alcohol and carbon dioxide. This step also forms additional molecules of ATP. It occurs in yeast, such as the yeast in bread. Carbon dioxide from alcoholic fermentation creates gas bubbles in bread dough. The bubbles leave little holes in the bread after it bakes. You can see them in the bread in Figure 4.16. The holes make the bread light and fluffy. "
_______process in which bacteria in yogurt produce ATP from glucose,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,D,"In lactic acid fermentation, glycolysis is followed by a step that produces lactic acid. This step forms additional molecules of ATP. Lactic acid fermentation occurs in some bacteria, including the bacteria in yogurt. The lactic acid gives unsweetened yogurt its sour taste. Your own muscle cells can also undertake lactic acid fermentation. This occurs when the cells are working very hard. They use fermentation because they cant get oxygen fast enough for aerobic respiration to supply them with all the energy they need. The muscle cells of the hurdlers in Figure 4.15 are using lactic acid fermentation by the time the athletes reach finish line. "
_______first stage of cellular respiration,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,A,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
_______final stage of cellular respiration,(A) aglycolysis (B) belectron transport (C) ccellular respiration (D) dlactic acid fermentation (E) eKrebs cycle (F) falcoholic fermentation (G) gmitochondrion,B,"The third and final stage of cellular respiration is called electron transport. Remember the other energy-storing molecules from glycolysis and the Krebs cycle? Their energy is used in this stage to make many more molecules of ATP. In fact, during this stage, as many as 34 molecules of ATP are produced. Electron transport requires oxygen, so this stage is also aerobic. The oxygen combines with hydrogen from the energy-storing molecules. This forms water, another waste product. "
Types of mutagens include,(A) radiation (B) viruses (C) bacteria (D) all of the above,D,"Mutations have many possible causes. Some mutations occur when a mistake is made during DNA replication or transcription. Other mutations occur because of environmental factors. Anything in the environment that causes a mutation is known as a mutagen. Examples of mutagens are shown in Figure 5.21. They include ultraviolet rays in sunlight, chemicals in cigarette smoke, and certain viruses and bacteria. "
"When a mutated codon codes for a different amino acid, the mutation is called a",(A) silent mutation (B) nonsense mutation (C) missense mutation (D) chromosomal mutation,C,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
Each gene codes for one,(A) codon (B) nucleotide (C) amino acid (D) protein,D,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
Which type of RNA carries genetic information from the nucleus to a ribosome?,(A) rRNA (B) tRNA (C) mRNA (D) none of the above,C,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
The backbone of the DNA molecule consists of,(A) sugars (B) phosphates (C) nitrogen bases (D) two of the above,D,"Nucleic acids consist of chains of small molecules called nucleotides. The structure of a nucleotide is shown in Figure 9.23. Each nucleotide contains a phosphate group (PO4 ), a sugar (C5 H8 O4 ) in DNA, and a nitrogen- containing base. (A base is a compound that is not neither acidic nor neutral.) There are four different nitrogenous bases in DNA. They are adenine, thymine, guanine, and cytosine. In RNA, the only difference is that thymine is replaced with a different base, uracil. DNA consists of two long chains of nucleotides. Nitrogen bases on the two chains form hydrogen bonds with each other. Adenine always bonds with thymine, and guanine always bonds with cytosine. These bonds hold the two chains together and give DNA is characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in Figure 9.24. Sugars and phosphate groups form the ""backbone"" of each chain of DNA. The bonded bases are called base pairs. RNA, in contrast to DNA, consists of just one chain of nucleotides. Determining the structure of DNA was a big scientific breakthrough. You can read the interesting story of its discovery at the URL below. "
A section of DNA that codes for a protein is called a,(A) base (B) codon (C) gene (D) chromosome,C,"A monomer is a molecule that can bind to other monomers to form a polymer. Amino acids are the monomers of a protein. The DNA sequence contains the instructions to place amino acids into a specific order. When the amino acid monomers are assembled in that specific order, proteins are made, a process called protein synthesis. In short, DNA contains the instructions to create proteins. But DNA does not directly make the proteins. Proteins are made on the ribosomes in the cytoplasm, and DNA (in an eukaryotic cell) is in the nucleus. So the cell uses an RNA intermediate to produce proteins. Each strand of DNA has many separate sequences that code for a specific protein. Insulin is an example of a protein made by your cells ( Figure 1.1). Units of DNA that contain code for the creation of a protein are called genes. "
Which statement about RNA is false?,(A) RNA stands for ribonucleic acid (B) RNA is smaller than DNA (C) RNA can cross the nuclear membrane (D) none of the above,D,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
Each codon in the genetic code,(A) consists of three nitrogen bases (B) codes for three amino acids (C) represents start and stop (D) none of the above,A,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
During the transcription step of protein synthesis,(A) DNA unwinds (B) DNA is copied to form rRNA (C) tRNA leaves the nucleus (D) amino acids are assembled at a ribosome,A,"Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as a template, nucleotides are joined together to make a complementary strand of mRNA. The mRNA contains bases that are complementary to the bases in the DNA strand. Translation is the second step in protein synthesis. It is shown in Figure 5.20. Translation takes place at a ribosome in the cytoplasm. During translation, the genetic code in mRNA is read to make a protein. Heres how it works: 1. 2. 3. 4. 5. The molecule of mRNA leaves the nucleus and moves to a ribosome. The ribosome consists of rRNA and proteins. It reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence. At the ribosome, the amino acids are joined together to form a chain of amino acids. The chain of amino acids keeps growing until a stop codon is reached. Then the chain is released from the ribosome. "
Some mutations occur when errors are made in copying DNA.,(A) true (B) false,A,"The process of DNA replication is not always 100% accurate. Sometimes the wrong base is inserted in the new strand of DNA. This wrong base could become permanent. A permanent change in the sequence of DNA is known as a mutation. Small changes in the DNA sequence are usually point mutations, which is a change in a single nucleotide. Once DNA has a mutation, that mutation will be copied each time the DNA replicates. After cell division, each resulting cell will carry the mutation. A mutation may have no effect. However, sometimes a mutation can cause a protein to be made incorrectly. A defect in the protein can affect how well the protein works, or whether it works at all. Usually the loss of a protein function is detrimental to the organism. In rare circumstances, though, the mutation can be beneficial. Mutations are a mechanism for how species evolve. For example, suppose a mutation in an animals DNA causes the loss of an enzyme that makes a dark pigment in the animals skin. If the population of animals has moved to a light colored environment, the animals with the mutant gene would have a lighter skin color and be better camouflaged. So in this case, the mutation is beneficial. "
The genetic code is the same in all living things.,(A) true (B) false,A,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
Mutations may be,(A) beneficial (B) neutral (C) harmful (D) any of the above,D,"Many mutations have no effect on the proteins they encode. These mutations are considered neutral. Occasionally, a mutation may make a protein even better than it was before. Or the protein might help the organism adapt to a new environment. These mutations are considered beneficial. An example is a mutation that helps bacteria resist antibiotics. Bacteria with the mutation increase in numbers, so the mutation becomes more common. Other mutations are harmful. They may even be deadly. Harmful mutations often result in a protein that no longer can do its job. Some harmful mutations cause cancer or other genetic disorders. Mutations also vary in their effects depending on whether they occur in gametes or in other cells of the body. Mutations that occur in gametes can be passed on to offspring. An offspring that inherits a mutation in a gamete will have the mutation in all of its cells. Mutations that occur in body cells cannot be passed on to offspring. They are confined to just one cell and its daughter cells. These mutations may have little effect on an organism. "
The translation step of protein synthesis takes place in the nucleus.,(A) true (B) false,B,"Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as a template, nucleotides are joined together to make a complementary strand of mRNA. The mRNA contains bases that are complementary to the bases in the DNA strand. Translation is the second step in protein synthesis. It is shown in Figure 5.20. Translation takes place at a ribosome in the cytoplasm. During translation, the genetic code in mRNA is read to make a protein. Heres how it works: 1. 2. 3. 4. 5. The molecule of mRNA leaves the nucleus and moves to a ribosome. The ribosome consists of rRNA and proteins. It reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence. At the ribosome, the amino acids are joined together to form a chain of amino acids. The chain of amino acids keeps growing until a stop codon is reached. Then the chain is released from the ribosome. "
Which type of mutation has no effect on the organism?,(A) silent (B) missense (C) nonsense (D) frameshift,A,"Many mutations have no effect on the proteins they encode. These mutations are considered neutral. Occasionally, a mutation may make a protein even better than it was before. Or the protein might help the organism adapt to a new environment. These mutations are considered beneficial. An example is a mutation that helps bacteria resist antibiotics. Bacteria with the mutation increase in numbers, so the mutation becomes more common. Other mutations are harmful. They may even be deadly. Harmful mutations often result in a protein that no longer can do its job. Some harmful mutations cause cancer or other genetic disorders. Mutations also vary in their effects depending on whether they occur in gametes or in other cells of the body. Mutations that occur in gametes can be passed on to offspring. An offspring that inherits a mutation in a gamete will have the mutation in all of its cells. Mutations that occur in body cells cannot be passed on to offspring. They are confined to just one cell and its daughter cells. These mutations may have little effect on an organism. "
What happens during the translation step of protein synthesis?,(A) Amino acids are joined together (B) The genetic code is carried to the nucleus (C) A molecule of mRNA forms (D) DNA moves to a ribosome,A,"Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as a template, nucleotides are joined together to make a complementary strand of mRNA. The mRNA contains bases that are complementary to the bases in the DNA strand. Translation is the second step in protein synthesis. It is shown in Figure 5.20. Translation takes place at a ribosome in the cytoplasm. During translation, the genetic code in mRNA is read to make a protein. Heres how it works: 1. 2. 3. 4. 5. The molecule of mRNA leaves the nucleus and moves to a ribosome. The ribosome consists of rRNA and proteins. It reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence. At the ribosome, the amino acids are joined together to form a chain of amino acids. The chain of amino acids keeps growing until a stop codon is reached. Then the chain is released from the ribosome. "
RNA is a double-stranded nucleic acid.,(A) true (B) false,B,"Nucleic acids are long chains of nucleotides. Nucleotides are made of a sugar, a nitrogen-containing base, and a phosphate group. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main nucleic acids. DNA is a double-stranded nucleic acid. DNA is the molecule that stores our genetic information ( Figure 1.6). The single- stranded RNA is involved in making proteins. ATP (adenosine triphosphate), known as the ""energy currency"" of the cell, is also a nucleic acid. "
Uracil is a nitrogen base found only in RNA.,(A) true (B) false,A,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
___A nonsense mutation is caused by a premature stop codon.,(A) true (B) false,A,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
___The function of RNA is to help build proteins.,(A) true (B) false,A,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
___The genetic code is the sequence of nitrogen bases in DNA.,(A) true (B) false,A,"How is the information for making proteins encoded in DNA? The answer is the genetic code. The genetic code is based on the sequence of nitrogen bases in DNA. The four bases make up the letters of the code. Groups of three bases each make up code words. These three-letter code words are called codons. Each codon stands for one amino acid or else for a start or stop signal. There are 20 amino acids that make up proteins. With three bases per codon, there are 64 possible codons. This is more than enough to code for the 20 amino acids plus start and stop signals. You can see how to translate the genetic code in Figure 5.17. Start at the center of the chart for the first base of each three-base codon. Then work your way out from the center for the second and third bases. Find the codon AUG in Figure 5.17. It codes for the amino acid methionine. It also codes for the start signal. After an AUG start codon, the next three letters are read as the second codon. The next three letters after that are read as the third codon, and so on. You can see how this works in Figure 5.18. The figure shows the bases in a molecule "
___Down syndrome is caused by a point mutation.,(A) true (B) false,B,"One common example of an extra-chromosome disorder is Down syndrome ( Figure 1.1). Children with Down syndrome are mentally disabled and also have physical deformities. Down syndrome occurs when a baby receives an extra chromosome 21 from one of his or her parents. Usually, a child will receive one chromosome 21 from the mother and one chromosome 21 from the father. In an individual with Down syndrome, however, there are three Chromosomes of a person with Down Syndrome. Notice the extra chromosome 21. copies of chromosome 21 ( Figure 1.2). Therefore, Down syndrome is also known as Trisomy 21. These people have 47 total chromosomes. Another example of a chromosomal disorder is Klinefelter syndrome, in which a male inherits an extra X chromosome. These individuals have an XXY genotype. They have underdeveloped sex organs and elongated limbs. They also have difficulty learning new things. "
___The codon AUG is the start codon.,(A) true (B) false,A,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
___A mutated codon always codes for a different amino acid.,(A) true (B) false,B,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
___RNA contains the sugar deoxyribose.,(A) true (B) false,B,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
_____nitrogen base found only in DNA,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,E,"As you can see in Figure 5.1, each nucleotide includes a sugar, a phosphate, and a nitrogen base. The sugar in DNA is called deoxyribose. There are four different nitrogen bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). Chemical bonds between the bases hold the two strands of DNA together. Adenine always bonds with thymine, and cytosine always bonds with guanine. These pairs of bases are called complementary base pairs. "
_____type of RNA that copies DNA in the nucleus,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,D,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
_____double-stranded nucleic acid,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,F,"Nucleic acids are long chains of nucleotides. Nucleotides are made of a sugar, a nitrogen-containing base, and a phosphate group. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main nucleic acids. DNA is a double-stranded nucleic acid. DNA is the molecule that stores our genetic information ( Figure 1.6). The single- stranded RNA is involved in making proteins. ATP (adenosine triphosphate), known as the ""energy currency"" of the cell, is also a nucleic acid. "
_____nitrogen base found only in RNA,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,A,"Nucleic acids consist of chains of small molecules called nucleotides. The structure of a nucleotide is shown in Figure 9.23. Each nucleotide contains a phosphate group (PO4 ), a sugar (C5 H8 O4 ) in DNA, and a nitrogen- containing base. (A base is a compound that is not neither acidic nor neutral.) There are four different nitrogenous bases in DNA. They are adenine, thymine, guanine, and cytosine. In RNA, the only difference is that thymine is replaced with a different base, uracil. DNA consists of two long chains of nucleotides. Nitrogen bases on the two chains form hydrogen bonds with each other. Adenine always bonds with thymine, and guanine always bonds with cytosine. These bonds hold the two chains together and give DNA is characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in Figure 9.24. Sugars and phosphate groups form the ""backbone"" of each chain of DNA. The bonded bases are called base pairs. RNA, in contrast to DNA, consists of just one chain of nucleotides. Determining the structure of DNA was a big scientific breakthrough. You can read the interesting story of its discovery at the URL below. "
_____type of RNA that helps form a ribosome,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,B,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
_____any single-stranded nucleic acid,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,C,"Nucleic acids are long chains of nucleotides. Nucleotides are made of a sugar, a nitrogen-containing base, and a phosphate group. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main nucleic acids. DNA is a double-stranded nucleic acid. DNA is the molecule that stores our genetic information ( Figure 1.6). The single- stranded RNA is involved in making proteins. ATP (adenosine triphosphate), known as the ""energy currency"" of the cell, is also a nucleic acid. "
_____type of RNA that brings amino acids to a ribosome,(A) auracil (B) brRNA (C) cRNA (D) dmRNA (E) ethymine (F) fDNA (G) gtRNA,G,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
Darwins theory of evolution includes the idea(s) that,(A) inherited traits of living things change over time (B) acquired characteristics can be passed on to offspring (C) artificial selection explains how evolution occurs (D) two of the above,A,"Darwins theory of evolution by natural selection contains two major ideas: One idea is that evolution happens. Evolution is a change in the inherited traits of organisms over time. Living things have changed as descendants diverged from common ancestors in the past. The other idea is that evolution occurs by natural selection. Natural selection is the process in which living things with beneficial traits produce more offspring. As a result, their traits increase in the population over time. "
Darwins famous book on evolution is called,(A) Adventures on the Beagle (B) On the Origin of Species (C) Evolution by Natural Selection (D) The Theory of Evolution,B,Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species. The book is very detailed and includes a lot of evidence for the theory. Darwins book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. 
The book described in question 1 was first published in,(A) 1801 (B) 1830 (C) 1859 (D) 1901,C,Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species. The book is very detailed and includes a lot of evidence for the theory. Darwins book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. 
The development of Darwins theory was influenced by his,(A) observations on the voyage of the Beagle (B) understanding of plant and animal breeding (C) knowledge of the writings of other scientists (D) all of the above,D,"Besides his observations on the Beagle, other influences helped Darwin develop his theory of evolution by natural selection. These included his knowledge of plant and animal breeding and the ideas of other scientists. "
Darwins book On the Origin of Species was first published,(A) more than 20 years after Darwin returned from his 5-year voyage (B) as soon as Darwin returned from his voyage on the Beagle (C) when Darwin was only 30 years of age (D) after Darwin died,A,Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species. The book is very detailed and includes a lot of evidence for the theory. Darwins book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. 
"Onboard the Beagle, Darwin served as the ships",(A) doctor (B) captain (C) naturalist (D) navigator,C,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
Darwin observed that the environment on different Galpagos Islands was correlated with the shell shape of,(A) snails (B) fossils (C) tortoises (D) none of the above,C,"The Galpagos Islands are still famous for their giant tortoises. These gentle giants are found almost nowhere else in the world. Darwin was amazed by their huge size. He was also struck by the variety of shapes of their shells. You can see two examples in Figure 7.3. Each island had tortoises with a different shell shape. The local people even could tell which island a tortoise came from based on the shape of its shell. Darwin wondered how each island came to have its own type of tortoise. He found out that tortoises with dome- shaped shells lived on islands where the plants they ate were abundant and easy to reach. Tortoises with saddle- shaped shells, in contrast, lived on islands that were drier. On those islands, food was often scarce. The saddle shape of their shells allowed tortoises on those islands to reach up and graze on vegetation high above them. This made sense, but how had it happened? "
Which statement about the Galpagos Islands is true?,(A) There are a total of sixteen Galpagos Islands (B) The Galpagos Islands are located in the Atlantic Ocean (C) The Galpagos Islands were the last stop on Darwins voyage (D) The Galpagos Islands are inhabited only by giant tortoises,A,"The Galpagos Islands are still famous for their giant tortoises. These gentle giants are found almost nowhere else in the world. Darwin was amazed by their huge size. He was also struck by the variety of shapes of their shells. You can see two examples in Figure 7.3. Each island had tortoises with a different shell shape. The local people even could tell which island a tortoise came from based on the shape of its shell. Darwin wondered how each island came to have its own type of tortoise. He found out that tortoises with dome- shaped shells lived on islands where the plants they ate were abundant and easy to reach. Tortoises with saddle- shaped shells, in contrast, lived on islands that were drier. On those islands, food was often scarce. The saddle shape of their shells allowed tortoises on those islands to reach up and graze on vegetation high above them. This made sense, but how had it happened? "
What types of specimens did Darwin collect on his voyage?,(A) plants (B) animals (C) rocks (D) all of the above,D,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
Galpagos Islanders could tell which island a giant tortoise came from based on the,(A) size of its feet (B) color of its skin (C) shape of its shell (D) number of its toes,C,"The Galpagos Islands are still famous for their giant tortoises. These gentle giants are found almost nowhere else in the world. Darwin was amazed by their huge size. He was also struck by the variety of shapes of their shells. You can see two examples in Figure 7.3. Each island had tortoises with a different shell shape. The local people even could tell which island a tortoise came from based on the shape of its shell. Darwin wondered how each island came to have its own type of tortoise. He found out that tortoises with dome- shaped shells lived on islands where the plants they ate were abundant and easy to reach. Tortoises with saddle- shaped shells, in contrast, lived on islands that were drier. On those islands, food was often scarce. The saddle shape of their shells allowed tortoises on those islands to reach up and graze on vegetation high above them. This made sense, but how had it happened? "
The Galpagos Islands are located off the west coast of,(A) North America (B) Africa (C) Australia (D) South America,D,"The Galpagos Islands are still famous for their giant tortoises. These gentle giants are found almost nowhere else in the world. Darwin was amazed by their huge size. He was also struck by the variety of shapes of their shells. You can see two examples in Figure 7.3. Each island had tortoises with a different shell shape. The local people even could tell which island a tortoise came from based on the shape of its shell. Darwin wondered how each island came to have its own type of tortoise. He found out that tortoises with dome- shaped shells lived on islands where the plants they ate were abundant and easy to reach. Tortoises with saddle- shaped shells, in contrast, lived on islands that were drier. On those islands, food was often scarce. The saddle shape of their shells allowed tortoises on those islands to reach up and graze on vegetation high above them. This made sense, but how had it happened? "
"In Galpagos finches, Darwin noted that beak size and shape seemed to reflect",(A) types of available food (B) species of dominant predators (C) kinds of nesting materials (D) sources of fresh water,A,"Darwin also observed that each of the Galpagos Islands had its own species of finches. The finches on different islands had beaks that differed in size and shape. You can see four examples in Figure 7.4. Darwin investigated further. He found that the different beaks seemed to suit the birds for the food available on their island. For example, finch number 1 in Figure 7.4 used its large, strong beak to crack open and eat big, tough seeds. Finch number 4 had a long, pointed beak that was ideal for eating insects. This seemed reasonable, but how had it come about? "
Darwins job on the Beagle was to observe and collect specimens wherever the ship went ashore.,(A) true (B) false,A,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
"Darwin never observed fossils, so they had no influence on his theory of evolution.",(A) true (B) false,B,"Besides his observations on the Beagle, other influences helped Darwin develop his theory of evolution by natural selection. These included his knowledge of plant and animal breeding and the ideas of other scientists. "
Darwin found that the different beaks of Galpagos finches seemed to suit them for different types of,(A) true (B) false,A,"Darwin also observed that each of the Galpagos Islands had its own species of finches. The finches on different islands had beaks that differed in size and shape. You can see four examples in Figure 7.4. Darwin investigated further. He found that the different beaks seemed to suit the birds for the food available on their island. For example, finch number 1 in Figure 7.4 used its large, strong beak to crack open and eat big, tough seeds. Finch number 4 had a long, pointed beak that was ideal for eating insects. This seemed reasonable, but how had it come about? "
Lamarcks ideas about evolution were influenced by Darwins theory of evolution by natural selection.,(A) true (B) false,B,"Darwin spent many years thinking about his own observations and the writings of Lamarck, Lyell, and Malthus. What did it all mean? How did it all fit together? The answer, of course, is the theory of evolution by natural selection. "
Darwins ideas about natural selection were influenced directly by a book written by Charles Lyell.,(A) true (B) false,B,"There were three other scientists in particular that influenced Darwin. Their names are Lamarck, Lyell, and Malthus. All three were somewhat older than Darwin, and he was familiar with their writings. Jean Baptiste Lamarck was a French naturalist. He was one of the first scientists to propose that species change over time. In other words, he proposed that evolution occurs. Lamarck also tried to explain how it happens, but he got that part wrong. Lamarck thought that the traits an organism developed during its life time could be passed on to its offspring. He called this the inheritance of acquired characteristics. Charles Lyell was an English geologist. He wrote a famous book called Principles of Geology. Darwin took the book with him on the Beagle. Lyell argued that geological processes such as erosion change Earths surface very gradually. To account for all the changes that had occurred on the planet, Earth must be a lot older than most people believed. Thomas Malthus was an English economist. He wrote a popular essay called On Population. He argued that human populations have the potential to grow faster than the resources they need. When populations get too big, disease and famine occur. These calamities control population size by killing off the weakest people. "
_The theory of evolution by natural selection explains and unifies all of life science.,(A) true (B) false,A,"Each field of life science has its own specific body of knowledge and relevant theories. However, two theories are basic to all of the life sciences. They form the foundation of every life science field. They are the cell theory and the theory of evolution by natural selection. Both theories have been tested repeatedly. Both are supported by a great deal of evidence. "
_All of the giant Galpagos tortoises are now extinct.,(A) true (B) false,B,"The Galpagos Islands are still famous for their giant tortoises. These gentle giants are found almost nowhere else in the world. Darwin was amazed by their huge size. He was also struck by the variety of shapes of their shells. You can see two examples in Figure 7.3. Each island had tortoises with a different shell shape. The local people even could tell which island a tortoise came from based on the shape of its shell. Darwin wondered how each island came to have its own type of tortoise. He found out that tortoises with dome- shaped shells lived on islands where the plants they ate were abundant and easy to reach. Tortoises with saddle- shaped shells, in contrast, lived on islands that were drier. On those islands, food was often scarce. The saddle shape of their shells allowed tortoises on those islands to reach up and graze on vegetation high above them. This made sense, but how had it happened? "
_Animal breeders produce animals with desired traits by selecting which animals are allowed to,(A) true (B) false,A,"Artificial selection occurs when humans select which plants or animals to breed in order to pass on specific traits to the next generation. For example, a farmer may choose to breed only cows that produce the best milk. Farmers would also avoid breeding cows that produce less milk. In this way, selective breeding of the cows would increase milk quality and quantity. Humans have also artificially bred dogs to create new breeds ( Figure 1.1). Artificial Selection: Humans used artificial selection to create these different breeds. Both dog breeds are descended from the same wolves, and their genes are almost identical. "
_Lamarcks explanation for how evolution occurs was essentially the same as Darwins.,(A) true (B) false,B,"Darwin spent many years thinking about his own observations and the writings of Lamarck, Lyell, and Malthus. What did it all mean? How did it all fit together? The answer, of course, is the theory of evolution by natural selection. "
"_According to Malthus, disease and famine kill off the weakest people when human populations",(A) true (B) false,A,"There are two different beliefs about what type of growth the human population will undergo in the future: 1. Neo-Malthusians believe that human population growth cannot continue without destroying the environment, and maybe humans themselves. 2. Cornucopians believe that the Earth can give humans a limitless amount of resources. They also believe that technology can solve problems caused by limited resources, such as lack of food. The Cornucopians believe that a larger population is good for technology and innovation. The 5-stage model above predicts that when all countries are industrialized, the human population will eventually level out. But many scientists and other Neo-Malthusians believe that humans have already gone over the Earths carrying capacity. That means, we may have already reached the maximum population size that can be supported, without destroying our resources and habitat. If this is true, then human overpopulation will lead to a lack of food and other resources. Overpopulation may also lead to increased disease, and/or war. These problems may cause the population of humans to crash. If these issues are not controlled, could the human population go extinct? Which of the above theories makes sense to you? Why? "
_Darwin knew nothing about the fossil evidence for evolution.,(A) true (B) false,B,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
_Darwins book on evolution by natural selection was rejected because it contained very little,(A) true (B) false,B,Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species. The book is very detailed and includes a lot of evidence for the theory. Darwins book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. 
___islands where Darwin made many important observations,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,C,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
___scientist who provided geologic evidence that Earth is very old,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,D,"During the 18th and 19th centuries, geologists tried to estimate the age of Earth with indirect techniques. What methods can you think of for doing this? One example is that by measuring how much sediment a stream deposited in a year, a geologist might try to determine how long it took for a stream to deposit an ancient sediment layer. Not surprisingly, these methods resulted in wildly different estimates. A relatively good estimate was produced by the British geologist Charles Lyell, who thought that 240 million years had passed since the appearance of the first animals with shells. Today scientists know that this event occurred about 530 million years ago. In 1892, William Thomson (later known as Lord Kelvin) calculated that the Earth was 100 million years old, which he later lowered to 20 million years. He did this systematically assuming that the planet started off as a molten ball and calculating the time it would take for it to cool to its current temperature. This estimate was a blow to geologists and supporters of Charles Darwins theory of evolution, which required an older Earth to provide time for geological and evolutionary processes to take place. Kelvins calculations were soon shown to be flawed when radioactivity was discovered in 1896. What Kelvin didnt know is that radioactive decay of elements inside Earths interior provides a steady source of heat. He also didnt know that the mantle is able to flow and so convection moves heat from the interior to the surface of the planet. Thomson had grossly underestimated Earths age. "
___scientist who argued that populations have the potential to grow faster than the resources they need,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,F,"There are two different beliefs about what type of growth the human population will undergo in the future: 1. Neo-Malthusians believe that human population growth cannot continue without destroying the environment, and maybe humans themselves. 2. Cornucopians believe that the Earth can give humans a limitless amount of resources. They also believe that technology can solve problems caused by limited resources, such as lack of food. The Cornucopians believe that a larger population is good for technology and innovation. The 5-stage model above predicts that when all countries are industrialized, the human population will eventually level out. But many scientists and other Neo-Malthusians believe that humans have already gone over the Earths carrying capacity. That means, we may have already reached the maximum population size that can be supported, without destroying our resources and habitat. If this is true, then human overpopulation will lead to a lack of food and other resources. Overpopulation may also lead to increased disease, and/or war. These problems may cause the population of humans to crash. If these issues are not controlled, could the human population go extinct? Which of the above theories makes sense to you? Why? "
___change in the inherited traits of organisms over time,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,E,"Many changes in the genetic makeup of a species may accumulate over time, especially if the environment is changing. Eventually the descendants will be very different from their ancestors and may become a whole new species. Changes in the genetic makeup of a species over time are known as biological evolution. "
___scientist who proposed that living things change over time through the inheritance of acquired,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,B,"There were three other scientists in particular that influenced Darwin. Their names are Lamarck, Lyell, and Malthus. All three were somewhat older than Darwin, and he was familiar with their writings. Jean Baptiste Lamarck was a French naturalist. He was one of the first scientists to propose that species change over time. In other words, he proposed that evolution occurs. Lamarck also tried to explain how it happens, but he got that part wrong. Lamarck thought that the traits an organism developed during its life time could be passed on to its offspring. He called this the inheritance of acquired characteristics. Charles Lyell was an English geologist. He wrote a famous book called Principles of Geology. Darwin took the book with him on the Beagle. Lyell argued that geological processes such as erosion change Earths surface very gradually. To account for all the changes that had occurred on the planet, Earth must be a lot older than most people believed. Thomas Malthus was an English economist. He wrote a popular essay called On Population. He argued that human populations have the potential to grow faster than the resources they need. When populations get too big, disease and famine occur. These calamities control population size by killing off the weakest people. "
___process in which living things with beneficial traits produce more offspring so their traits increase,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,A,"At some point, the variation probably came from a mutation. A mutation is a random change in an organisms genes. Mutations are natural. Some are harmful, but many are neutral. If the trait from the mutation is beneficial, that organism may have a better chance to survive. An organism that survives is likely to have offspring. If it does, it may pass the mutation on to its offspring. The offspring may be more likely to survive. "
___scientist who proposed the theory of evolution by natural selection,(A) anatural selection (B) bLamarck (C) cGalpagos (D) dLyell (E) eevolution (F) fMalthus (G) gDarwin,G,Darwin finally published his theory of evolution by natural selection in 1859. He presented it in his book On the Origin of Species. The book is very detailed and includes a lot of evidence for the theory. Darwins book changed science forever. The theory of evolution by natural selection became the unifying theory of all life science. 
Remains of organisms become fossils when their organic matter is replaced by,(A) traces (B) bones (C) amber (D) minerals,D,Most fossils form when a dead organism is buried in sediment. Layers of sediment slowly build up. The sediment is buried and turns into sedimentary rock. The remains inside the rock also turn to rock. The remains are replaced by minerals. The remains literally turn to stone. Fossilization is illustrated in Figure 11.2. 
_Evidence for evolution includes millions of fossils.,(A) true (B) false,A,"Fossils are the preserved remains of animals, plants, and other organisms from the distant past. Examples of fossils include bones, teeth, and impressions. By studying fossils, evidence for evolution is revealed. Paleontologists are scientists who study fossils to learn about life in the past. Fossils allow these scientists to determine the features of extinct species. Paleontologists compare the features of species from different periods in history. With this information, they try to understand how species have evolved over millions of years ( Figure below). Until recently, fossils were the main source of evidence for evolution ( Figure below). Through studying fossils, we now know that todays organisms look much different in many cases than those that were alive in the past. Scientists have also shown that organisms were spread out differently across the planet. Earthquakes, volcanoes, shifting seas, and other movements of the continents have all affected where organisms live and how they adapted to their changing environments. "
_Fossils generally form from the hard parts of organisms.,(A) true (B) false,A,"The soft parts of organisms almost always decompose quickly after death. Thats why most fossils consist of hard parts such as bones. Its rare even for hard parts to remain intact long enough to become fossils. Fossils form when water seeps through the remains and deposits minerals in them. The remains literally turn to stone. Remains are more likely to form fossils if they are covered quickly by sediments. Once in a while, remains are preserved almost unchanged. For example, they may be frozen in glaciers. Or they may be trapped in tree resin that hardens to form amber. Thats what happened to the wasp in Figure 7.8. The wasp lived about 20 million years ago, but even its fragile wings have been preserved by the amber. "
The relative ages of fossils are based on their,(A) similarities in DNA (B) amounts of carbon-14 (C) positions in rock layers (D) approximate age in years,C,"Fossils are useful for reconstructing the past only if they can be dated. Scientists need to determine when the organisms lived who left behind the fossils. Fossils can be dated in two different ways: absolute dating and relative dating. Absolute dating determines about how long ago a fossil organism lived. This gives the fossil an approximate age in years. Absolute dating is often based on the amount of carbon-14 or other radioactive element that remains in a fossil. You can learn how carbon-14 dating works by watching this short video: Relative dating determines which of two fossils is older or younger than the other but not their age in years. Relative dating is based on the positions of fossils in rock layers. Lower rock layers were laid down earlier, so they are assumed to contain older fossils. This is illustrated in Figure 7.9. "
Which statement about the evolution of mammals is true?,(A) Mammals first evolved in the ocean (B) The earliest mammals evolved about 2 million years ago (C) All modern mammals have the same bones in their front limbs (D) all of the above,C,"Their adaptations have allowed mammals to spread to even more environments than reptiles. The success of mammals is due to several of their unique traits. Mammals are endothermic and have fur, hair, or blubber for warmth. Mammals can swim, fly, and live in nearly all terrestrial environments. Mammals initially filled the forests that covered many early Cenozoic lands. Over time, the forests gave way to grasslands, which created more niches for mammals to fill. "
_It is very common for dead organisms to become fossils.,(A) true (B) false,B,"Becoming a fossil isnt easy. Only a tiny percentage of the organisms that have ever lived become fossils. Why do you think only a tiny percentage of living organisms become fossils after death? Think about an antelope that dies on the African plain (Figure 1.2). Most of its body is eaten by hyenas and other scavengers and the remaining flesh is devoured by insects and bacteria. Only bones are left behind. As the years go by, the bones are scattered and fragmented into small pieces, eventually turning into dust. The remaining nutrients return to the soil. This antelope will not be preserved as a fossil. Is it more likely that a marine organism will become a fossil? When clams, oysters, and other shellfish die, the soft parts quickly decay, and the shells are scattered. In shallow water, wave action grinds them into sand-sized pieces. The shells are also attacked by worms, sponges, and other animals (Figure 1.3). How about a soft bodied organism? Will a creature without hard shells or bones become a fossil? There is virtually no fossil record of soft bodied organisms such as jellyfish, worms, or slugs. Insects, which are by far the most common land animals, are only rarely found as fossils (Figure 1.4). "
_Remains are less likely to become fossils if they are covered quickly by sediments.,(A) true (B) false,B,"Quick burial is essential because most decay and fragmentation occurs at the surface. Marine animals that die near a river delta may be rapidly buried by river sediments. A storm at sea may shift sediment on the ocean floor, covering a body and helping to preserve its skeletal remains (Figure 1.5). This fish was quickly buried in sediment to become a fossil. Quick burial is rare on land, so fossils of land animals and plants are less common than marine fossils. Land People buried by the extremely hot eruption of ash and gases at Mt. Vesuvius in 79 AD. "
Which organism has DNA that is least like human DNA?,(A) honeybee (B) chicken (C) grape (D) cow,C,"Scientists can compare the DNA or proteins of different species. If the molecules are similar, this shows that the species are related. The more similar the molecules are, the closer the relationship is likely to be. When molecules are used in this way, they are called molecular clocks. This method assumes that random mutations occur at a constant rate for a given protein or segment of DNA. Over time, the mutations add up. The longer the amount of time since species diverged, the more differences there will be in their DNA or proteins. Table 7.1 compares the DNA of four different organisms with modern human DNA. The DNA of chimpanzees is almost 99 percent the same as the DNA of modern humans. This shows that chimpanzees are very closely related to us. We are less closely related to the other organisms in the table. Its no surprise that grapes, which are plants, are less like us than the animals in the table. Organism Chimpanzee Cow Chicken Honeybee Grape Similarity with Human DNA (percent the same) 98.8 85 65 44 24 "
_Some fossils form when dead organisms are frozen in glaciers.,(A) true (B) false,A,Most fossils form when a dead organism is buried in sediment. Layers of sediment slowly build up. The sediment is buried and turns into sedimentary rock. The remains inside the rock also turn to rock. The remains are replaced by minerals. The remains literally turn to stone. Fossilization is illustrated in Figure 11.2. 
The best evidence for evolution is the,(A) fossil record (B) comparison of embryos (C) data from radioactive elements (D) observation of traits changing through time,D,"Arguably, some of the best evidence of evolution comes from examining the molecules and DNA found in all living things. Beginning in the 1940s, scientists studying molecules and DNA have confirmed conclusions about evolution drawn from other forms of evidence. Molecular clocks are used to determine how closely two species are related by calculating the number of differences between the species DNA sequences or amino acid sequences. These clocks are sometimes called gene clocks or evolutionary clocks. The fewer the differences, the less time since the species split from each other and began to evolve into different species ( Figure 1.1). A chicken and a gorilla will have more differences between their DNA and amino acid sequences than a gorilla and an orangutan. That means the chicken and gorilla had a common ancestor a very long time ago, while the gorilla and orangutan shared a more recent common ancestor. This provides additional evidence that the gorilla and orangutan are more closely related than the gorilla and the chicken. Which pair of organisms would have more molecular differences, a mammal and a bird, a mammal and a frog, or a mammal and a fish? On the other hand, animals may look similar but can have very different DNA sequences and evolutionary ancestry. Which would have more DNA sequences in common, a whale and a horse, or a whale and a shark? Almost all organisms are made from DNA with the same building blocks. The genomes (all of the genes in an organism) of all mammals are almost identical. The genomes, or all the DNA sequences of all the genes of an organism, have been determined for many different organisms. The comparison of genomes provides new information about the relationships among species and how evolution occurs ( Figure 1.2). Molecular evidence for evolution also includes: 1. The same biochemical building blocks, such as amino acids and nucleotides, are found in all organisms, from bacteria to plants and animals. Recall that amino acids are the building blocks of proteins, and nucleotides are the building blocks of DNA and RNA. 2. DNA and RNA determine the development of all organisms. 3. The similarities and differences between the genomes confirm patterns of evolution. "
_Relative dating can be used to determine how long ago a fossil organism lived.,(A) true (B) false,B,"Fossils are useful for reconstructing the past only if they can be dated. Scientists need to determine when the organisms lived who left behind the fossils. Fossils can be dated in two different ways: absolute dating and relative dating. Absolute dating determines about how long ago a fossil organism lived. This gives the fossil an approximate age in years. Absolute dating is often based on the amount of carbon-14 or other radioactive element that remains in a fossil. You can learn how carbon-14 dating works by watching this short video: Relative dating determines which of two fossils is older or younger than the other but not their age in years. Relative dating is based on the positions of fossils in rock layers. Lower rock layers were laid down earlier, so they are assumed to contain older fossils. This is illustrated in Figure 7.9. "
_Fossil evidence shows that whales evolved from mammals that had always lived in the ocean.,(A) true (B) false,B,"The evolution of whales is a good example of how fossils can help us understand evolution. Scientists have long known that mammals first evolved on land about 200 million years ago. Its been a mystery, however, how whales evolved. Whales are mammals that live completely in the water. Did they evolve from earlier land mammals? Or did they evolve from animals that already lived in the water? Starting in the late 1970s, a growing number of fossils have allowed scientists to piece together the story of whale evolution. The fossils represent ancient, whale-like animals. They show that an ancient land mammal made its way back to the sea more than 50 million years ago. It became the ancestor of modern whales. In doing so, it lost its legs and became adapted to life in the water. In Figure 7.10 you can see an artists rendition of such a whale ancestor. It had legs and could walk on land, but it was also a good swimmer. Watch this short video to learn more about the amazing story of whale evolution based on the fossils: "
The footprints of animals are sometimes preserved as fossils.,(A) true (B) false,A,"Fossils are preserved remains or traces of organisms that lived in the past. Most preserved remains are hard parts, such as teeth, bones, or shells. Examples of these kinds of fossils are pictured in Figure 11.1. Preserved traces can include footprints, burrows, or even wastes. Examples of trace fossils are also shown in Figure 11.1. "
Carbon-14 dating is a method of relative dating.,(A) true (B) false,B,"The best-known method of radiometric dating is carbon-14 dating. A living thing takes in carbon-14 (along with stable carbon-12). As the carbon-14 decays, it is replaced with more carbon-14. After the organism dies, it stops taking in carbon. That includes carbon-14. The carbon-14 that is in its body continues to decay. So the organism contains less and less carbon-14 as time goes on. We can estimate the amount of carbon-14 that has decayed by measuring the amount of carbon-14 to carbon-12. We know how fast carbon-14 decays. With this information, we can tell how long ago the organism died. Carbon-14 has a relatively short half-life. It decays quickly compared to some other unstable isotopes. So carbon- 14 dating is useful for specimens younger than 50,000 years old. Thats a blink of an eye in geologic time. But radiocarbon dating is very useful for more recent events. One important use of radiocarbon is early human sites. Carbon-14 dating is also limited to the remains of once-living things. To date rocks, scientists use other radioactive isotopes. "
Some fossils form when organisms are preserved in amber.,(A) true (B) false,A,"Fossils may form in other ways. With complete preservation, the organism doesnt change much. As seen below, tree sap may cover an organism and then turn into amber. The original organism is preserved so that scientists might be able to study its DNA. Organisms can also be completely preserved in tar or ice. Molds and casts are another way organisms can be fossilized. A mold is an imprint of an organism left in rock. The organisms remains break down completely. Rock that fills in the mold resembles the original remains. The fossil that forms in the mold is called a cast. Molds and casts usually form in sedimentary rock. With compression, an organisms remains are put under great pressure inside rock layers. This leaves behind a dark stain in the rock. You can read about them in Figure 11.3. "
Whales evolved from a four-legged ancestor.,(A) true (B) false,A,"The evolution of whales is a good example of how fossils can help us understand evolution. Scientists have long known that mammals first evolved on land about 200 million years ago. Its been a mystery, however, how whales evolved. Whales are mammals that live completely in the water. Did they evolve from earlier land mammals? Or did they evolve from animals that already lived in the water? Starting in the late 1970s, a growing number of fossils have allowed scientists to piece together the story of whale evolution. The fossils represent ancient, whale-like animals. They show that an ancient land mammal made its way back to the sea more than 50 million years ago. It became the ancestor of modern whales. In doing so, it lost its legs and became adapted to life in the water. In Figure 7.10 you can see an artists rendition of such a whale ancestor. It had legs and could walk on land, but it was also a good swimmer. Watch this short video to learn more about the amazing story of whale evolution based on the fossils: "
Closely related animals generally look more similar as they grow older.,(A) true (B) false,B,"Even though two different species may not look similar, they may have similar internal structures that suggest they have a common ancestor. That means both evolved from the same ancestor organism a long time ago. Common ancestry can also be determined by looking at the structure of the organism as it first develops. "
___any method of estimating the age of fossils that determines only which of two fossils is older or,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,C,"Fossils are useful for reconstructing the past only if they can be dated. Scientists need to determine when the organisms lived who left behind the fossils. Fossils can be dated in two different ways: absolute dating and relative dating. Absolute dating determines about how long ago a fossil organism lived. This gives the fossil an approximate age in years. Absolute dating is often based on the amount of carbon-14 or other radioactive element that remains in a fossil. You can learn how carbon-14 dating works by watching this short video: Relative dating determines which of two fossils is older or younger than the other but not their age in years. Relative dating is based on the positions of fossils in rock layers. Lower rock layers were laid down earlier, so they are assumed to contain older fossils. This is illustrated in Figure 7.9. "
___any evidence other than organic remains that a living organism leaves behind,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,E,"A fossil is any remains or traces of an ancient organism. Fossils include body fossils, left behind when the soft parts have decayed away, and trace fossils, such as burrows, tracks, or fossilized coprolites (feces) as seen above. Collections of fossils are known as fossil assemblages. "
___molecule that is compared among species to estimate how long it has been since they diverged from,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,B,"Scientists can compare the DNA or proteins of different species. If the molecules are similar, this shows that the species are related. The more similar the molecules are, the closer the relationship is likely to be. When molecules are used in this way, they are called molecular clocks. This method assumes that random mutations occur at a constant rate for a given protein or segment of DNA. Over time, the mutations add up. The longer the amount of time since species diverged, the more differences there will be in their DNA or proteins. Table 7.1 compares the DNA of four different organisms with modern human DNA. The DNA of chimpanzees is almost 99 percent the same as the DNA of modern humans. This shows that chimpanzees are very closely related to us. We are less closely related to the other organisms in the table. Its no surprise that grapes, which are plants, are less like us than the animals in the table. Organism Chimpanzee Cow Chicken Honeybee Grape Similarity with Human DNA (percent the same) 98.8 85 65 44 24 "
___hardened tree resin,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,A,"Conifers, members of the phylum Coniferophyta, are probably the gymnosperms that are most familiar to you. Conifers include trees such as pines, firs, spruces, cedars, and the coastal redwood trees in California, which are the tallest living vascular plants. Conifers have their reproductive structures in cones, but they are not the only plants to have that trait ( Figure 1.1). Conifer pollen cones are usually very small, while the seed cones are larger. Pollen contains gametophytes that produce the male gamete of seed plants. The pollen, which is a powder-like substance, is carried by the wind to fertilize the seed cones that contain the female gamete ( Figure 1.2). Conifers have many uses. They are important sources of lumber and are also used to make paper. Resins, the sticky substance you might see oozing out of a wound on a pine tree, are collected from conifers to make a variety of products, such as the solvent turpentine and the rosin used by musicians and baseball players. The sticky rosin improves the pitchers hold on the ball or increases the friction between the bow and the strings to help create music from a violin or other stringed instrument. "
___body part that is no longer used but is still present in modern organisms,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,G,"Some of the most interesting evidence for evolution comes from vestigial structures. These are body parts that are no longer used but are still present in modern organisms. Examples in humans include tail bones and the appendix. Human beings obviously dont have tails, but our ancestors did. We still have bones at the base of our spine that form a tail in other, related animals, such as monkeys. The appendix is a tiny remnant of a once-larger organ. In a distant ancestor, it was needed to digest food. If your appendix becomes infected, a surgeon can remove it. You wont miss it because it no longer has any purpose in the human body. "
___any method of estimating the age of fossils that provides an approximate age in years,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,F,The rate of decay of unstable isotopes can be used to estimate the absolute ages of fossils and rocks. This type of dating is called radiometric dating. 
___very early stage of development of an organism,(A) aamber (B) bmolecular clock (C) crelative dating (D) dembryo (E) etrace (F) fabsolute dating (G) gvestigial structure,D,"An embryo is an organism in the earliest stages of development. Embryos of different species may look quite similar, even when the adult forms look very different. Look at the drawings of embryos in Figure 7.12. They represent very early life stages of a chicken, turtle, pig, and human being. The embryos look so similar that its hard to tell them apart. Such similarities provide evidence that all four types of animals are related. They help document that evolution has occurred. "
Most of what we know about dinosaurs is based on,(A) molecular data (B) similarities in embryos (C) vestigial organs (D) fossils,D,"Of course the most famous Mesozoic reptiles were the dinosaurs (Figure 1.2). Dinosaurs reigned for 160 million years and had tremendous numbers and diversity. Species of dinosaurs filled all the niches that are currently filled by mammals. Dinosaurs were plant eaters, meat eaters, bipedal, quadrupedal, endothermic (warm-blooded), exothermic (cold-blooded), enormous, small, and some could swim or fly. Scientists now think that some dinosaurs were endotherms (warm-blooded) due to the evidence that has been collected over the decades. There are still some scientists who do not agree, but the amount of evidence makes it likely. Some dinosaurs lived in polar regions where animals that needed sunlight for warmth could not survive in winter. Dinosaurs bones had canals, similar to those of birds, indicating that they grew fast and were very active. Fast growth usually indicates an active metabolism typical of endotherms. Dinosaurs had erect posture and large brains, both correlated with endothermy. The earliest known fossil of a flowering plant is this 125 million year old Creta- ceous fossil. "
Which of the following parts of animals are most likely to be preserved as fossils?,(A) skin (B) feathers (C) hair (D) teeth,D,"Usually its only the hard parts that are fossilized. The fossil record consists almost entirely of the shells, bones, or other hard parts of animals. Mammal teeth are much more resistant than other bones, so a large portion of the mammal fossil record consists of teeth. The shells of marine creatures are common also. "
"The front limbs of whales, bats, and cats",(A) look very different (B) are used for different purposes (C) have the same basic bone structure (D) all of the above,D,"Comparing body parts of different species may reveal evidence for evolution. For example, all mammals have front limbs that look quite different and are used for different purposes. Bats use their front limbs to fly, whales use them to swim, and cats use them to run and climb. However, the front limbs of all three animalsas well as humanshave the same basic underlying bone structure. You can see this in Figure 7.11. The similar bones provide evidence that all four animals evolved from a common ancestor. "
The use of molecular clocks assumes that,(A) more similar molecules reflect closer relationships (B) mutations occur at an increasing rate for a given molecule (C) most molecules are identical in all living species (D) all of the above,A,"Scientists can compare the DNA or proteins of different species. If the molecules are similar, this shows that the species are related. The more similar the molecules are, the closer the relationship is likely to be. When molecules are used in this way, they are called molecular clocks. This method assumes that random mutations occur at a constant rate for a given protein or segment of DNA. Over time, the mutations add up. The longer the amount of time since species diverged, the more differences there will be in their DNA or proteins. Table 7.1 compares the DNA of four different organisms with modern human DNA. The DNA of chimpanzees is almost 99 percent the same as the DNA of modern humans. This shows that chimpanzees are very closely related to us. We are less closely related to the other organisms in the table. Its no surprise that grapes, which are plants, are less like us than the animals in the table. Organism Chimpanzee Cow Chicken Honeybee Grape Similarity with Human DNA (percent the same) 98.8 85 65 44 24 "
The Grants observed an increase in the average size of finch beaks during a,(A) drought (B) hurricane (C) cold spell (D) volcanic eruption,A,"The best evidence for evolution comes from actually observing changes in organisms through time. In the 1970s, biologists Peter and Rosemary Grant went to the Galpagos Islands to do fieldwork. They wanted to re-study Darwins finches. They spent the next 40 years on the project. Their hard work paid off. They were able to document evolution by natural selection taking place in the finches. A period of very low rainfall occurred while the Grants were on the islands. The drought resulted in fewer seeds for the finches to eat. Birds with smaller beaks could eat only the smaller seeds. Birds with bigger beaks were better off. They could eat seeds of all sizes. Therefore, there was more food available to them. Many of the small-beaked birds died in the drought. More of the big-beaked birds survived and reproduced. Within just a couple of years, the average beak size in the finches increased. This was clearly evolution by natural selection. "
Fossils most often form when minerals in water turn the remains of organisms to,(A) vestigial structures (B) sediments (C) bones (D) stones,D,Most fossils form when a dead organism is buried in sediment. Layers of sediment slowly build up. The sediment is buried and turns into sedimentary rock. The remains inside the rock also turn to rock. The remains are replaced by minerals. The remains literally turn to stone. Fossilization is illustrated in Figure 11.2. 
What percent of chimpanzee DNA is the same as human DNA?,(A) 244 (B) 444 (C) 888 (D) 988,D,"Gorillas, chimpanzees, and humans have more than 97% of their DNA sequence in common. This means that a similar percent of the amino acid sequences of the proteins will be the same, resulting in many proteins with similar or identical functions. All organisms in the Hominidae communicate with some kind of language. They can also create simple cultures beyond the family or group of animals. Having a culture means that knowledge and behaviors can be passed on from generation to generation. "
Darwin thought that evolution occurs,(A) very slowly (B) very rarely (C) at a varying rate (D) only on islands,A,"Darwin thought that evolution occurs very slowly. This is likely if conditions are stable. But what if conditions are changing rapidly? Evolution is likely to occur more rapidly as well. For example, the Grants showed that evolution occurred in just a couple of years in Darwins finches. This happened when a severe drought killed off a lot of the plants that the birds needed for food. Millions of fossils have been found since Darwins time. They show that evolution may occur in fits and starts. Long period of little or gradual change may be interrupted by bursts of rapid change. The rate of evolution is influenced by how the environment is changing. Today, Earths climate is changing rapidly. How do you think this might affect the rate of evolution? "
___all the genes in all the members of a population,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,G,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
___random change in a small populations allele frequencies,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,F,"There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in allele frequencies that occurs because some genotypes are more fit than others. Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation. This is the force of evolution that Darwin identified. Figure 23.12 shows how Darwin thought natural selection led to variation in finches on the Galpagos Islands. "
A gene pool consists of,(A) all the alleles for a given gene in an individual (B) all the alleles for all the genes in a given species (C) all the alleles for a given gene in a population (D) none of the above,D,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
All of the following are considered to be forces of evolution except,(A) mutation (B) natural selection (C) genetic flow (D) climate change,D,"There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in allele frequencies that occurs because some genotypes are more fit than others. Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation. This is the force of evolution that Darwin identified. Figure 23.12 shows how Darwin thought natural selection led to variation in finches on the Galpagos Islands. "
___process in which two species evolve the same traits because they live in similar habitats,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,D,"Sometimes two species evolve the same traits. It happens because they live in similar habitats. This is called convergent evolution. Caribbean Anoles demonstrate this as well. On each Caribbean island, anoles in similar habitats evolved the same traits. For example, anoles that lived on the forest floor evolved long legs for leaping and running on the ground. Anoles that lived on tree branches evolved short legs that helped them cling to small branches and twigs. Anoles that lived at the tops of trees evolved large toe pads that allowed them to walk on leaves without falling. On each of the islands, there were anole species that evolved in each of these same ways. "
___change in allele frequencies that occurs because some genotypes are more fit than others,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,E,"There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in allele frequencies that occurs because some genotypes are more fit than others. Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation. This is the force of evolution that Darwin identified. Figure 23.12 shows how Darwin thought natural selection led to variation in finches on the Galpagos Islands. "
"In a population of 200 people, 20 people have the genotype BB and 180 people have the genotype bb. What is the frequency of the B allele in this population?",(A) 00 (B) 01 (C) 02 (D) 05,B,"Consider a purple-flowered pea plant with the genotype Bb. Half the gametes produced by this parent will have a B allele. The other half will have a b allele. You can see this in Figure 6.7. This is similar to tossing a coin. There is a 50 percent chance of a head and a 50 percent chance of a tail. Like a head or tail, there is a 50 percent chance that any gamete from this parent will have the B allele. There is also a 50 percent chance that any gamete will have the b allele. "
___number of copies of an allele divided by the total number of alleles for the gene in a gene pool,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,B,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
The ultimate source of new genetic variation is,(A) mutation (B) artificial selection (C) evolution (D) genetic drift,A,"For natural selection to take place, organisms must vary in their traits. Asexual reproduction results in offspring that are all the same. They are also identical to the parent cell. So how can prokaryotes increase genetic variation? They can exchange plasmids. This is called genetic transfer. It may happen by direct contact between cells. Or a ""bridge"" may form between cells. Genetic transfer mixes the genes of different cells. It creates new combinations of alleles. "
___group of organisms of the same species that live in the same area,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,A,A population consists of all individuals of a single species that exist together at a given place and time. A species is a single type of organism that can interbreed and produce fertile offspring. All of the populations living together in the same area make up a community. 
___movement of genes into or out of a population,(A) apopulation (B) ballele frequency (C) cgene flow (D) dconvergent evolution (E) enatural selection (F) fgenetic drift (G) ggene pool,C,"Migration is the movement of individual organisms into, or out of, a population. Migration affects population growth rate. There are two types of migration: 1. Immigration is the movement of individuals into a population from other areas. This increases the population size and growth rate. 2. Emigration is the movement of individuals out of a population. This decreases the population size and growth rate. The earlier growth rate equation can be modified to account for migration: growth rate = (birth rate + immigration rate) (death rate + emigration rate). One type of migration that you are probably familiar with is the migration of birds. Maybe you have heard that birds fly south for the winter. In the fall, birds fly thousands of miles to the south where it is warmer. In the spring, they return to their homes. ( Figure 1.2). Monarch butterflies also migrate from Mexico to the northern U.S. in the summer and back to Mexico in the winter. These types of migrations move entire populations from one location to another. A flock of barnacle geese fly in formation during the autumn migration. "
"Darwin knew Mendels laws, so he understood how traits are inherited.",(A) true (B) false,B,"At first, Mendel studied one trait at a time. This was his first set of experiments. These experiments led to his first law, the law of segregation. Then Mendel studied two traits at a time. This was his second set of experiments. These experiments led to his second law, the law of independent assortment. "
Horses became smaller as they evolved over the past 50 million years.,(A) true (B) false,B,"Humans evolved during the later Cenozoic. New fossil discoveries alter the details of what we know about the evolution of modern humans, but the major evolutionary path is well understood. "
Microevolution can be measured by changes in allele frequencies.,(A) true (B) false,A,Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. 
A total of 300 fossils have been discovered since Darwins time.,(A) true (B) false,B,"Of all the organisms that ever lived, only a tiny number became fossils. Still, scientists learn a lot from fossils. Fossils are our best clues about the history of life on Earth. "
"Once a new species forms, it stops evolving.",(A) true (B) false,B,"Many changes in the genetic makeup of a species may accumulate over time, especially if the environment is changing. Eventually the descendants will be very different from their ancestors and may become a whole new species. Changes in the genetic makeup of a species over time are known as biological evolution. "
_It takes millions of years for microevolution to occur.,(A) true (B) false,B,Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. 
_Individuals can evolve if their allele frequencies change.,(A) true (B) false,B,Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. 
_The evolution the Grants observed in finches was macroevolution.,(A) true (B) false,B,"The best evidence for evolution comes from actually observing changes in organisms through time. In the 1970s, biologists Peter and Rosemary Grant went to the Galpagos Islands to do fieldwork. They wanted to re-study Darwins finches. They spent the next 40 years on the project. Their hard work paid off. They were able to document evolution by natural selection taking place in the finches. A period of very low rainfall occurred while the Grants were on the islands. The drought resulted in fewer seeds for the finches to eat. Birds with smaller beaks could eat only the smaller seeds. Birds with bigger beaks were better off. They could eat seeds of all sizes. Therefore, there was more food available to them. Many of the small-beaked birds died in the drought. More of the big-beaked birds survived and reproduced. Within just a couple of years, the average beak size in the finches increased. This was clearly evolution by natural selection. "
_Population size determines how quickly allele frequencies change by genetic drift.,(A) true (B) false,A,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
_A gene pool is described by its allele frequencies.,(A) true (B) false,A,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
_Darwin thought that evolution occurs very quickly.,(A) true (B) false,B,"Darwin thought that evolution occurs very slowly. This is likely if conditions are stable. But what if conditions are changing rapidly? Evolution is likely to occur more rapidly as well. For example, the Grants showed that evolution occurred in just a couple of years in Darwins finches. This happened when a severe drought killed off a lot of the plants that the birds needed for food. Millions of fossils have been found since Darwins time. They show that evolution may occur in fits and starts. Long period of little or gradual change may be interrupted by bursts of rapid change. The rate of evolution is influenced by how the environment is changing. Today, Earths climate is changing rapidly. How do you think this might affect the rate of evolution? "
_Mutation alone can cause rapid evolution.,(A) true (B) false,B,"Darwin thought that evolution occurs very slowly. This is likely if conditions are stable. But what if conditions are changing rapidly? Evolution is likely to occur more rapidly as well. For example, the Grants showed that evolution occurred in just a couple of years in Darwins finches. This happened when a severe drought killed off a lot of the plants that the birds needed for food. Millions of fossils have been found since Darwins time. They show that evolution may occur in fits and starts. Long period of little or gradual change may be interrupted by bursts of rapid change. The rate of evolution is influenced by how the environment is changing. Today, Earths climate is changing rapidly. How do you think this might affect the rate of evolution? "
Forces of evolution include,(A) gene flow (B) genetic drift (C) mutation (D) all of the above,D,"There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in allele frequencies that occurs because some genotypes are more fit than others. Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation. This is the force of evolution that Darwin identified. Figure 23.12 shows how Darwin thought natural selection led to variation in finches on the Galpagos Islands. "
How did horses change as they evolved over the past 50 million years?,(A) Their body size increased (B) Their number of toes increased (C) Their number of legs decreased (D) all of the above,A,"Adaptations in a species add up. If the environment is stable, the species wont change. But if the environment is changing, the species will need to adapt. Many adaptations may be necessary. In time, the species may change a lot. The descendants will be very different from their ancestors. They may even become a new species. This process is called evolution. Evolution happens as a species changes over time. Organisms alive today evolved from earlier life forms. We can learn about this from fossils. For example, horse fossils from 60 million years ago are very different from modern horses. Ancient horses were much smaller than they are today (Figure 12.12). The horses teeth and hooves have also changed. The horses evolved because of changes in their environment. "
"In a population of 100 individuals, there are 50 AA individuals and 50 aa individuals. What is the frequency of the A allele in this population?",(A) 00 (B) 05 (C) 07 (D) 10,B,"A population is a group of organisms of the same species that live in the same area. All the genes in all the members of a population make up the populations gene pool. For each gene, the gene pool includes all the different alleles in the population. The gene pool can be described by its allele frequencies for specific genes. The frequency of an allele is the number of copies of that allele divided by the total number of alleles for the gene in the gene pool. A simple example will help you understand these concepts. The data in Table 7.2 represent a population of 100 individuals. For each gene, the gene pool has a total of 200 alleles (2 per individual x 100 individuals). The gene in question exists as two different alleles, A and a. The number of A alleles in the gene pool is 140. Of these, 100 are in the 50 AA homozygotes. Another 40 are in the 40 Aa heterozygotes. The number of a alleles in the gene pool is 60. Of these, 40 are in the 40 Aa heterozygotes. Another 20 are in the 10 aa homozygotes. The frequency of the A allele is 140/200 = 0.7. The frequency of the a allele is 60/200 = 0.3. Genotype AA Aa aa Totals Number of Individuals 50 40 10 100 Number of A Alleles 100 (50 x 2) 40 (40 x 1) 0 (10 x 0) 140 Number of a Alleles 0 (50 x 0) 40 (40 x 1) 20 (10 x 2) 60 Evolution occurs in a population when its allele frequencies change over time. For example, the frequency of the A allele might change from 0.7 to 0.8. If that happens, evolution has occurred. What causes allele frequencies to change? The answer is forces of evolution. "
Darwin thought that evolution occurs by,(A) genetic drift (B) natural selection (C) mutation (D) gene flow,B,"Darwins theory of evolution by natural selection contains two major ideas: One idea is that evolution happens. Evolution is a change in the inherited traits of organisms over time. Living things have changed as descendants diverged from common ancestors in the past. The other idea is that evolution occurs by natural selection. Natural selection is the process in which living things with beneficial traits produce more offspring. As a result, their traits increase in the population over time. "
A group of organisms that can mate and produce fertile offspring together is called a(n),(A) gene pool (B) population (C) species (D) splinter group,C,A population consists of all individuals of a single species that exist together at a given place and time. A species is a single type of organism that can interbreed and produce fertile offspring. All of the populations living together in the same area make up a community. 
Anole lizards in similar habitats on different Caribbean Islands evolved the same traits. This is an example of,(A) coevolution (B) speciation (C) convergent evolution (D) genetic drift,C,"Sometimes two species evolve the same traits. It happens because they live in similar habitats. This is called convergent evolution. Caribbean Anoles demonstrate this as well. On each Caribbean island, anoles in similar habitats evolved the same traits. For example, anoles that lived on the forest floor evolved long legs for leaping and running on the ground. Anoles that lived on tree branches evolved short legs that helped them cling to small branches and twigs. Anoles that lived at the tops of trees evolved large toe pads that allowed them to walk on leaves without falling. On each of the islands, there were anole species that evolved in each of these same ways. "
Plants and the animals that pollinate them may evolve matching traits. This is an example of,(A) gene flow (B) coevolution (C) convergent evolution (D) none of the above,B,"Two species may often interact with each other and have a close relationship. Examples include flowers and the animals that pollinate them. When one of the two species evolves new traits, the other species may evolve matching traits. This is called coevolution. You can see an example of this in Figure 7.16. The very long beak of this hummingbird co-evolved with the tubular flowers it pollinates. Only this species of hummingbird can reach nectar deep in the flowers. "
Earths second mass extinction occurred at the end of the,(A) Cambrian Period (B) Triassic Period (C) Permian Period (D) Tertiary Period,C,"The largest mass extinction in Earths history occurred at the end of the Permian period, about 250 million years ago. In this catastrophe, it is estimated that more than 95% of marine species on Earth went extinct. Marine species with calcium carbonate shells and skeletons suffered worst. About 70% of terrestrial vertebrate species (land animals) suffered the same fate. This was the only known mass extinction of insects. This mass extinction appears to have taken place in three pulses, with three separate causes. Gradual environmental change, an asteroid impact, intense volcanism, or changes in the composition of the atmosphere may all have played a role. Click image to the left or use the URL below. URL: "
Life first appeared on Earth about,(A) 46 billion years ago (B) 40 billion years ago (C) 46 million years ago (D) 40 million years ago,B,"Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria. These first life forms were, of course, very basic, and this then allowed for the evolution of more complex life forms. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion. This sudden burst of evolution may have been caused by some environmental changes that made the Earths environment more suitable for a wider variety of life forms. Plants and fungi did not appear until roughly 500 million years ago. They were soon followed by arthropods (insects and spiders). Next came the amphibians about 300 million years ago, followed by mammals around 200 million years ago and birds around 100 million years ago. Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotessmall, relatively simple single-celled organisms. As it is difficult to identify, observe and study such small forms of life, most of these organisms remain unknown to scientists. Advancing technologies, however, do allow for the identification and study of such organisms. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist. The basic timeline of a 4.6 billion-year-old Earth includes the following: About 3.5 - 3.8 billion years of simple cells (prokaryotes). 3 billion years of photosynthesis. 2 billion years of complex cells (eukaryotes). 1 billion years of multicellular life. 600 million years of simple animals. 570 million years of arthropods (ancestors of insects, arachnids and crustaceans). 550 million years of complex animals. 500 million years of fish and proto-amphibians. 475 million years of land plants. 400 million years of insects and seeds. 360 million years of amphibians. 300 million years of reptiles. 200 million years of mammals. 150 million years of birds. 130 million years of flowers. 65 million years since the non-avian dinosaurs died out. 2.5 million years since the appearance of Homo. 200,000 years since the appearance of modern humans. 25,000 years since Neanderthals died out. "
The geologic time scale is based on major changes in,(A) geology (B) climate (C) organisms (D) all of the above,D,The geologic time scale may include illustrations of how life on Earth has changed. Major events on Earth may also be shown. These include the formation of the major mountains or the extinction of the dinosaurs. Figure 11.14 is a different kind of the geologic time scale. It shows how Earths environment and life forms have changed. 
"If Earths history is represented by a 24-hour day, then life first appears at about",(A) 3:00 am (B) 8:00 am (C) 1:00 pm (D) 3:00 pm,A,Its hard to grasp the vast amounts of time since Earth formed and life first appeared. It may help to think of Earths history as a 24-hour day. 
Which of the following divisions of the geologic time scale is longest?,(A) epoch (B) era (C) period (D) eon,D,"The largest blocks of time on the geologic time scale are called eons. Eons are split into eras. Each era is divided into periods. Periods may be further divided into epochs. Geologists may just use early or late. An example is late Jurassic, or early Cretaceous. Figure 11.13 shows you what the geologic time scale looks like. "
Which feature of modern Earth was absent when the planet first formed?,(A) solid crust (B) oceans (C) atmosphere (D) all of the above,D,"When Earth first formed, it was a fiery hot, barren ball. It had no oceans or atmosphere. Rivers of melted rock flowed over its surface. Gradually, the planet cooled and formed a solid crust. Gases from volcanoes formed an atmosphere, although it contained only a trace of oxygen. As the planet continued to cool, clouds formed and rain fell. Rainwater helped form oceans. The ancient atmosphere and oceans would be toxic to modern life, but they set the stage for life to begin. "
The earliest living things were,(A) autotrophs (B) heterotrophs (C) eukaryotes (D) two of the above,B,"The earliest cells were prokaryotes (Figure 1.1). Although prokaryotes have a cell membrane, they lack a cell nucleus and other organelles. Without a nucleus, RNA was loose within the cell. Over time the cells became more complex. LUCA was a prokaryote but differed from the first living cells because its genetic code was based on DNA. The oldest fossils are tiny microbe-like objects that are 3.5 billion years old. Evidence for bacteria, the first single-celled life forms, goes back 3.5 billion years (Figure 1.2). "
The earliest cells,(A) had a nucleus (B) made their own food (C) got energy from organic molecules (D) two of the above,C,"The earliest cells were prokaryotes (Figure 1.1). Although prokaryotes have a cell membrane, they lack a cell nucleus and other organelles. Without a nucleus, RNA was loose within the cell. Over time the cells became more complex. LUCA was a prokaryote but differed from the first living cells because its genetic code was based on DNA. The oldest fossils are tiny microbe-like objects that are 3.5 billion years old. Evidence for bacteria, the first single-celled life forms, goes back 3.5 billion years (Figure 1.2). "
The first multicellular organisms evolved about,(A) 40 billion years ago (B) 36 billion years ago (C) 30 billion years ago (D) none of the above,D,"Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria. These first life forms were, of course, very basic, and this then allowed for the evolution of more complex life forms. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion. This sudden burst of evolution may have been caused by some environmental changes that made the Earths environment more suitable for a wider variety of life forms. Plants and fungi did not appear until roughly 500 million years ago. They were soon followed by arthropods (insects and spiders). Next came the amphibians about 300 million years ago, followed by mammals around 200 million years ago and birds around 100 million years ago. Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotessmall, relatively simple single-celled organisms. As it is difficult to identify, observe and study such small forms of life, most of these organisms remain unknown to scientists. Advancing technologies, however, do allow for the identification and study of such organisms. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist. The basic timeline of a 4.6 billion-year-old Earth includes the following: About 3.5 - 3.8 billion years of simple cells (prokaryotes). 3 billion years of photosynthesis. 2 billion years of complex cells (eukaryotes). 1 billion years of multicellular life. 600 million years of simple animals. 570 million years of arthropods (ancestors of insects, arachnids and crustaceans). 550 million years of complex animals. 500 million years of fish and proto-amphibians. 475 million years of land plants. 400 million years of insects and seeds. 360 million years of amphibians. 300 million years of reptiles. 200 million years of mammals. 150 million years of birds. 130 million years of flowers. 65 million years since the non-avian dinosaurs died out. 2.5 million years since the appearance of Homo. 200,000 years since the appearance of modern humans. 25,000 years since Neanderthals died out. "
Organisms that evolved at the beginning of the Paleozoic Era included,(A) trilobites (B) sponges (C) reptiles (D) two of the above,D,The Paleozoic saw the evolution a tremendous diversity of life throughout the seas and onto land. 
The first mass extinction on Earth occurred at the end of the,(A) Precambrian Supereon (B) Permian Period (C) Mesozoic Era (D) Cretaceous Period,A,"The largest mass extinction in Earths history occurred at the end of the Permian period, about 250 million years ago. In this catastrophe, it is estimated that more than 95% of marine species on Earth went extinct. Marine species with calcium carbonate shells and skeletons suffered worst. About 70% of terrestrial vertebrate species (land animals) suffered the same fate. This was the only known mass extinction of insects. This mass extinction appears to have taken place in three pulses, with three separate causes. Gradual environmental change, an asteroid impact, intense volcanism, or changes in the composition of the atmosphere may all have played a role. Click image to the left or use the URL below. URL: "
Primates and human ancestors first appeared during the,(A) Jurassic Period (B) Tertiary Period (C) Devonian Period (D) Quaternary Period,B,"Humans evolved from primates, and apes and humans have a primate common ancestor. About 7 million years ago, chimpanzees (our closest living relatives) and humans shared their last common ancestor. "
___major division of Earths history that is known as the age of dinosaurs,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,E,The Permian mass extinction paved the way for another burst of new life at the start of the Mesozoic Era. This era is known as the age of dinosaurs. It is divided into three periods. 
___first major division of Earths history,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,B,"The Precambrian Supereon is the first major division of Earths history (see Figure 7.18). It covers the time from Earths formation 4.6 billion years ago to 544 million years ago. To see how life evolved during the Precambrian and beyond, watch this wonderful video. Its a good introduction to the rest of the lesson. MEDIA Click image to the left or use the URL below. URL: "
___major division of Earths history that is called the age of mammals,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,C,The extinction of the dinosaurs at the end of the Mesozoic Era paved the way for mammals to take over. Thats why the Cenozoic Era is called the age of mammals. They soon became the dominant land animals on Earth. The Cenozoic is divided into two periods. 
___event in which the majority of Earths species die out,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,F,"Extinction is the complete dying out of a species. Once a species goes extinct, it can never return. More than 99 percent of all the species that ever lived on Earth have gone extinct. Five mass extinctions have occurred in Earths history. They were caused by major geologic and climatic events. The fifth mass extinction wiped out the dinosaurs 65 million years ago. "
The Jurassic Period is called the golden age of dinosaurs.,(A) true (B) false,A,"The Triassic mass extinction gave dinosaurs the opportunity to really flourish during the Jurassic Period. Thats why this period is called the golden age of dinosaurs. The earliest birds also evolved during the Jurassic from dinosaur ancestors. In addition, all the major groups of mammals appeared. Flowering plants also appeared for the first time. New insects evolved to pollinate them. The continents continued to move apart. "
Mammals became the dominant land animals during the Mesozoic Era.,(A) true (B) false,B,The extinction of the dinosaurs at the end of the Mesozoic Era paved the way for mammals to take over. Thats why the Cenozoic Era is called the age of mammals. They soon became the dominant land animals on Earth. The Cenozoic is divided into two periods. 
"___division of Earths history into eons, eras, and periods",(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,G,"Another tool for understanding the history of Earth and its life is the geologic time scale. You can see this time scale in Figure 7.18. It divides Earths history into eons, eras, and periods. These divisions are based on major changes in geology, climate, and the evolution of life. The geologic time scale organizes Earths history on the basis of important events instead of time alone. It also puts more focus on recent events, about which we know the most. "
The last ice age ended about 12 million years ago.,(A) true (B) false,B,"The last major ice age took place in the Pleistocene. This epoch lasted from 2 million to 14,000 years ago. Earths temperature was only 5 C (9 F) cooler than it is today. But glaciers covered much of the Northern Hemisphere. In Figure 17.17, you can see how far south they went. Clearly, a small change in temperature can have a big impact on the planet. Humans lived during this ice age. "
___major division of Earths history that began with the Cambrian explosion,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,A,"The Cambrian began with the most rapid and far-reaching evolution of life forms ever in Earths history. Evolving to inhabit so many different habitats resulted in a tremendous diversification of life forms. Shallow seas covered the lands, so every major marine organism group, including nearly all invertebrate animal phyla, evolved during this time. With the evolution of hard body parts, fossils are much more abundant and better preserved from this period than from the Precambrian. The Burgess shale formation in the Rocky Mountains of British Columbia, Canada, contains an amazing diversity of middle Cambrian life forms, from about 505 million years ago. Paleontologists do not agree on whether the Burgess shale fossils can all be classified into modern groups of organisms or whether many represent lines that have gone completely extinct. "
___single cell believed to have given rise to all of the following life on Earth,(A) aPaleozoic Era (B) bPrecambrian Supereon (C) cCenozoic Era (D) dLUCA (E) eMesozoic Era (F) fmass extinction (G) ggeologic time scale,D,"The earliest cells were prokaryotes (Figure 1.1). Although prokaryotes have a cell membrane, they lack a cell nucleus and other organelles. Without a nucleus, RNA was loose within the cell. Over time the cells became more complex. LUCA was a prokaryote but differed from the first living cells because its genetic code was based on DNA. The oldest fossils are tiny microbe-like objects that are 3.5 billion years old. Evidence for bacteria, the first single-celled life forms, goes back 3.5 billion years (Figure 1.2). "
The current geological era is the Cenozoic Era.,(A) true (B) false,A,"The Cenozoic began around 65.5 million years ago and continues today. Although it accounts for only about 1.5% of the Earths total history, as the most recent era it is the one scientists know the most about. Much of what has been discussed elsewhere in CK-12 Earth Science Concepts For High School describes the geological situation of the Cenozoic. A few highlights are mentioned here. "
"When Earth first formed, it had oceans but no atmosphere.",(A) true (B) false,B,"When Earth first formed, it was a fiery hot, barren ball. It had no oceans or atmosphere. Rivers of melted rock flowed over its surface. Gradually, the planet cooled and formed a solid crust. Gases from volcanoes formed an atmosphere, although it contained only a trace of oxygen. As the planet continued to cool, clouds formed and rain fell. Rainwater helped form oceans. The ancient atmosphere and oceans would be toxic to modern life, but they set the stage for life to begin. "
"_During Earths history, continents drifted and collided.",(A) true (B) false,A,"Earths crust consists of many tectonic plates that move over time. Due to plate tectonics, the continents changed their shapes and positions during Earth history. As the continents changed, so did the oceans. About 250 million years ago, there was one huge land mass known as Pangaea. There was also one huge ocean called Panthalassa. You can see it in Figure 14.2. By 180 million years ago, Pangaea began to break up. The continents started to drift apart. They slowly moved to where they are today. The movement of the continents caused Panthalassa to break into smaller oceans. These oceans are now known as the Pacific, Atlantic, Indian, and Arctic Oceans. The waters of all the oceans are connected. "
"_If Earths history is represented by a 24-hour day, humans appear at about 8:00 pm.",(A) true (B) false,B,"Figure 7.17 shows the history of Earth in a day. In this model, the planet forms at midnight. The first prokaryotes evolve around 3:00 am. Eukaryotes evolve at about 1:00 pm. Animals dont evolve until almost 8:00 pm. Humans appear only in the last minute of the day. Relating these major events in Earths history to a 24-hour day helps to put them in perspective. "
_Earths earliest atmosphere contained more oxygen than the atmosphere does today.,(A) true (B) false,B,"Earths first atmosphere was different from the current one. The gases came from two sources. Volcanoes spewed gases into the air. Comets carried in ices from outer space. These ices warmed and became gases. Nitrogen, carbon dioxide, hydrogen, and water vapor, or water in gas form, were in the first atmosphere (Figure 12.5). Take a look at the list of gases. Whats missing? The early atmosphere had almost no oxygen. "
_A total of four mass extinctions have occurred on Earth since life began.,(A) true (B) false,B,"The largest mass extinction in Earths history occurred at the end of the Permian period, about 250 million years ago. In this catastrophe, it is estimated that more than 95% of marine species on Earth went extinct. Marine species with calcium carbonate shells and skeletons suffered worst. About 70% of terrestrial vertebrate species (land animals) suffered the same fate. This was the only known mass extinction of insects. This mass extinction appears to have taken place in three pulses, with three separate causes. Gradual environmental change, an asteroid impact, intense volcanism, or changes in the composition of the atmosphere may all have played a role. Click image to the left or use the URL below. URL: "
_Fish first evolved during the Paleozoic Era.,(A) true (B) false,A,"Paleozoic life was most diverse in the oceans. Paleozoic seas were full of worms, snails, clams, trilobites, sponges, and brachiopods. Organisms with shells were common. The first fish were simple, armored, jawless fish. Fish have internal skeletons. Some, like sharks, skates, and rays, have skeletons of cartilage. More advanced fish have skeletons of bones. Fish evolved jaws and many other adaptations for ocean life. Figure 12.13 shows some of the diversity of Earths oceans. "
_The Jurassic Period is known as the golden age of mammals.,(A) true (B) false,B,"The Triassic mass extinction gave dinosaurs the opportunity to really flourish during the Jurassic Period. Thats why this period is called the golden age of dinosaurs. The earliest birds also evolved during the Jurassic from dinosaur ancestors. In addition, all the major groups of mammals appeared. Flowering plants also appeared for the first time. New insects evolved to pollinate them. The continents continued to move apart. "
_The extinction of the dinosaurs paved the way for reptiles to take over.,(A) true (B) false,B,"Of course the most famous Mesozoic reptiles were the dinosaurs (Figure 1.2). Dinosaurs reigned for 160 million years and had tremendous numbers and diversity. Species of dinosaurs filled all the niches that are currently filled by mammals. Dinosaurs were plant eaters, meat eaters, bipedal, quadrupedal, endothermic (warm-blooded), exothermic (cold-blooded), enormous, small, and some could swim or fly. Scientists now think that some dinosaurs were endotherms (warm-blooded) due to the evidence that has been collected over the decades. There are still some scientists who do not agree, but the amount of evidence makes it likely. Some dinosaurs lived in polar regions where animals that needed sunlight for warmth could not survive in winter. Dinosaurs bones had canals, similar to those of birds, indicating that they grew fast and were very active. Fast growth usually indicates an active metabolism typical of endotherms. Dinosaurs had erect posture and large brains, both correlated with endothermy. The earliest known fossil of a flowering plant is this 125 million year old Creta- ceous fossil. "
Which statement about the diversity of bacteria is false?,(A) Bacteria are the most diverse organisms on Earth (B) Thousands of species of bacteria have been discovered (C) Few if any bacterial species remain to be discovered (D) Bacteria increase diversity by genetic transfer,C,"Bacteria are the most diverse organisms on Earth. Thousands of species of bacteria have been discovered. Many more are thought to exist. The known species are classified on the basis of various traits. For example, they may be classified by the shape of their cells. They may also be classified by how they react to a dye called Gram stain. "
Salmonella bacteria are,(A) prokaryotes (B) bacillus bacteria (C) a common cause of food poisoning (D) all of the above,D,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
Bacteria,(A) are the most abundant organisms on Earth (B) have fewer species than any other domain (C) can be observed only with an electron microscope (D) all of the above,A,"Bacteria are the most successful organisms on the planet. They lived on this planet for two billion years before the first eukaryotes and, during that time, evolved into millions of different species. "
Bacteria that are classified as gram-negative,(A) stain purple with gram stain (B) have an outer membrane (C) lack a cell wall (D) two of the above,B,"Different types of bacteria stain a different color when Gram stain is applied to them. This makes them easy to identify. Some stain purple and some stain red, as you can see in Figure 8.11. The two types differ in their outer layers. This explains why they stain differently. Bacteria that stain purple are called gram-positive bacteria. They have a thick cell wall without an outer membrane. Bacteria that stain red are called gram-negative bacteria. They have a thin cell wall with an outer membrane. "
Bacteria can help people by,(A) making fuels (B) cleaning up oil spills (C) making vaccines (D) all of the above,D,"Bacteria help usand all other living thingsby decomposing wastes. In this way, they recycle carbon and nitrogen in ecosystems. In addition, photosynthetic cyanobacteria are important producers. On ancient Earth, they added oxygen to the atmosphere and changed the course of evolution forever. There are billions of bacteria inside the human digestive tract. They help us digest food. They also make vitamins and play other important roles. We use bacteria in many other ways as well. For example, we use them to: create medical products such as vaccines. transfer genes in gene therapy. make fuels such as ethanol. clean up oil spills. kill plant pests. ferment foods. Do you eat any of the fermented foods pictured in Figure 8.12? If so, you are eating bacteria and their wastes. Yum! "
Gram-positive bacteria have a(n),(A) thick cell wall (B) outer membrane (C) cell nucleus (D) two of the above,A,"Different types of bacteria stain a different color when Gram stain is applied to them. This makes them easy to identify. Some stain purple and some stain red, as you can see in Figure 8.11. The two types differ in their outer layers. This explains why they stain differently. Bacteria that stain purple are called gram-positive bacteria. They have a thick cell wall without an outer membrane. Bacteria that stain red are called gram-negative bacteria. They have a thin cell wall with an outer membrane. "
Lyme disease is caused by bacteria that are spread by,(A) mosquitoes (B) black flies (C) deer ticks (D) bed bugs,C,"You have ten times as many bacterial cells as human cells in your body. Luckily for you, most of these bacteria are harmless. However, some of them can cause disease. Any organism that causes disease is called a pathogen. Diseases caused by bacterial pathogens include food poisoning, strep throat, and Lyme disease. Bacteria that cause disease may spread directly from person to person. For example, they may spread when people shake hands with, or sneeze on, other people. Bacteria may also spread through food, water, or objects that have become contaminated with them. Some bacteria are spread by vectors. A vector is an organism that spreads bacteria or other pathogens. Most vectors are animals, commonly insects. For example, deer ticks like the one in Figure 8.13 spread Lyme disease. Ticks carry Lyme disease bacteria from deer to people when they bite them. "
All bacteria,(A) die at temperatures higher than 37 C (B) can be killed with chlorine bleach (C) are resistant to antibiotics (D) are poisoned by oxygen,B,"Bacteria are the most abundant living things on Earth. They live in almost all environments. They are found in the air, ocean, soil, and intestines of animals. They are even found in rocks deep below Earths surface. Any surface that has not been sterilized is likely to be covered with bacteria. The total number of bacteria in the world is amazing. Its estimated to be about 5 million trillion trillion. If you write that number in digits, it has 30 zeroes! "
Bacteria live in Earths,(A) crust (B) ocean (C) atmosphere (D) all of the above,D,"Bacteria are the most abundant living things on Earth. They live in almost all environments. They are found in the air, ocean, soil, and intestines of animals. They are even found in rocks deep below Earths surface. Any surface that has not been sterilized is likely to be covered with bacteria. The total number of bacteria in the world is amazing. Its estimated to be about 5 million trillion trillion. If you write that number in digits, it has 30 zeroes! "
How many bacterial cells normally live in and on the human body?,(A) a few hundred (B) about a thousand (C) several million (D) trillions,D,"Your skin is covered by millions of bacteria. Millions more live inside your body, mainly in your gastrointestinal tract. Most of these bacteria are helpful. For one thing, they help defend your body from pathogens. They do it by competing with harmful bacteria for food and space. They prevent the harmful bacteria from multiplying and making you sick. "
The development of antibiotic resistance is an example of,(A) gene therapy (B) biotechnology (C) gene cloning (D) natural selection,D,"You already know that evolution is the change in species over time. Most evolutionary changes are small and do not lead to the creation of a new species. When populations change in small ways over time, the process is called microevolution. Microevolution results in changes within a species. An example of microevolution is the evolution of mosquitoes that cannot be killed by pesticides, called pesticide- resistant mosquitoes. Imagine that you have a pesticide that kills most of the mosquitoes in your state. Through a random mutation, some of the mosquitoes have resistance to the pesticide. As a result of the widespread use of this pesticide, most of the remaining mosquitoes are the pesticide-resistant mosquitoes. When these mosquitoes repro- duce the next year, they produce more mosquitoes with the pesticide-resistant trait. Soon, most of the mosquitoes in your state are resistant to the pesticide. This is an example of microevolution because the number of mosquitoes with this trait changed. However, this evolutionary change did not create a new species of mosquito because the pesticide-resistant mosquitoes can still reproduce with other non-pesticide-resistant mosquitoes. "
The best way to kill bacteria in drinking water is to,(A) raise its temperature to the boiling point (100 C) (B) add a large amount of chlorine bleach to it (C) dissolve antibiotic drugs in it (D) pass it through a sieve,A,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
A spiral-shaped bacterium is classified as a spirillus.,(A) true (B) false,A,"Bacteria come in several different shapes. The different shapes can be seen by examining bacteria under a light microscope. Therefore, its relatively easy to classify them by shape. There are three types of bacteria based on shape: bacilli (bacillus, singular), or rod shaped. cocci (coccus, singular), or sphere shaped. spirilli (spirillus, singular), or spiral shaped. You can see a common example of each type of bacteria in Figure 8.10. "
Bacteria that form biofilms are multicellular prokaryotes.,(A) true (B) false,B,"Some prokaryotes form structures consisting of many individual cells, like the cells in Figure 8.7. This is called a biofilm. A biofilm is a colony of prokaryotes that is stuck to a surface. The surface might be a rock or a hosts tissues. The sticky plaque that collects on your teeth between brushings is a biofilm. It consists of millions of prokaryotic cells. "
Bacteria cover Earths surface but are not found far below it.,(A) true (B) false,B,"Bacteria are the most abundant living things on Earth. They live in almost all environments. They are found in the air, ocean, soil, and intestines of animals. They are even found in rocks deep below Earths surface. Any surface that has not been sterilized is likely to be covered with bacteria. The total number of bacteria in the world is amazing. Its estimated to be about 5 million trillion trillion. If you write that number in digits, it has 30 zeroes! "
There are more bacteria than any other organisms on Earth.,(A) true (B) false,A,"Bacteria are the most abundant living things on Earth. They live in almost all environments. They are found in the air, ocean, soil, and intestines of animals. They are even found in rocks deep below Earths surface. Any surface that has not been sterilized is likely to be covered with bacteria. The total number of bacteria in the world is amazing. Its estimated to be about 5 million trillion trillion. If you write that number in digits, it has 30 zeroes! "
Yogurt is made with the help of bacteria.,(A) true (B) false,A,"Bacteria can be used to make cheese from milk. The bacteria turn the milk sugars into lactic acid. The acid is what causes the milk to curdle to form cheese. Bacteria are also involved in producing other foods. Yogurt is made by using bacteria to ferment milk ( Figure 1.1). Fermenting cabbage with bacteria produces sauerkraut. Yogurt is made from milk fermented with bacteria. The bacteria ingest natural milk sugars and release lactic acid as a waste product, which causes proteins in the milk to form into a solid mass, which becomes the yogurt. "
__A book lying on your desk is likely to be covered with bacteria.,(A) true (B) false,A,"You are not aware of them, but your skin is covered by millions (or more!) of bacteria. Millions more live inside your body. Most of these bacteria help defend your body from pathogens. How do they do it? They compete with harmful bacteria for food and space. This prevents the harmful bacteria from multiplying and making you sick. "
__Bacteria are the most diverse organisms on Earth.,(A) true (B) false,A,"Bacteria are the most diverse organisms on Earth. Thousands of species of bacteria have been discovered. Many more are thought to exist. The known species are classified on the basis of various traits. For example, they may be classified by the shape of their cells. They may also be classified by how they react to a dye called Gram stain. "
__Bacteria stain differently with gram stain depending on whether they have a cell nucleus.,(A) true (B) false,B,"Different types of bacteria stain a different color when Gram stain is applied to them. This makes them easy to identify. Some stain purple and some stain red, as you can see in Figure 8.11. The two types differ in their outer layers. This explains why they stain differently. Bacteria that stain purple are called gram-positive bacteria. They have a thick cell wall without an outer membrane. Bacteria that stain red are called gram-negative bacteria. They have a thin cell wall with an outer membrane. "
__All bacteria cause human illnesses.,(A) true (B) false,B,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
__Some bacteria can be used as pesticides.,(A) true (B) false,A,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
__Pickles and cheese on a cheeseburger are both made with the help of bacteria.,(A) true (B) false,A,"Bacteria can be used to make cheese from milk. The bacteria turn the milk sugars into lactic acid. The acid is what causes the milk to curdle to form cheese. Bacteria are also involved in producing other foods. Yogurt is made by using bacteria to ferment milk ( Figure 1.1). Fermenting cabbage with bacteria produces sauerkraut. Yogurt is made from milk fermented with bacteria. The bacteria ingest natural milk sugars and release lactic acid as a waste product, which causes proteins in the milk to form into a solid mass, which becomes the yogurt. "
__Strep throat is a bacterial infection.,(A) true (B) false,A,"There are also ways that bacteria can be harmful to humans and other animals. Bacteria are responsible for many types of human illness ( Figure 1.1), including: Strep throat Tuberculosis Pneumonia Leprosy Lyme disease Luckily most of these can be treated with antibiotics, which kill the bacteria. It is important that when a medical doctor prescribes antibiotics for you, you take the medicine exactly as the doctor tells you. You need to make sure the bacteria is killed. "
____sphere-shaped bacterium,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,F,"Bacteria are so small that they can only be seen with a microscope. When viewed under the microscope, they have three distinct shapes ( Figure 1.1). Bacteria can be identified and classified by their shape: 1. Bacilli are rod-shaped. 2. Cocci are sphere-shaped. 3. Spirilli are spiral-shaped. Bacteria come in many different shapes. Some of the most common shapes are bacilli (rods), cocci (spheres), and spirilli (spirals). Bacteria can be identified and classified by their shape. "
____organism that spreads pathogens from host to host,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,C,"Still other pathogens are spread by vectors. A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects, such as ticks and mosquitoes. These insects tend to transfer protozoan or viral parasites. When an insect bites an infected person or animal, it picks up the pathogen. Then the pathogen travels to the next person or animal it bites. Ticks carry the bacteria that cause Lyme disease. Mosquitoes ( Figure serious symptoms may develop. Other diseases spread by mosquitoes include Dengue Fever and Yellow Fever. The first case of West Nile virus in North America occurred in 1999. Within just a few years, the virus had spread throughout most of the United States. Birds as well as humans can be infected with the virus. Birds often fly long distances. This is one reason why West Nile virus spread so quickly. "
____name of the dye used to color bacteria,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,A,"Different types of bacteria stain a different color when Gram stain is applied to them. This makes them easy to identify. Some stain purple and some stain red, as you can see in Figure 8.11. The two types differ in their outer layers. This explains why they stain differently. Bacteria that stain purple are called gram-positive bacteria. They have a thick cell wall without an outer membrane. Bacteria that stain red are called gram-negative bacteria. They have a thin cell wall with an outer membrane. "
____rod-shaped bacterium,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,D,"Bacteria come in several different shapes. The different shapes can be seen by examining bacteria under a light microscope. Therefore, its relatively easy to classify them by shape. There are three types of bacteria based on shape: bacilli (bacillus, singular), or rod shaped. cocci (coccus, singular), or sphere shaped. spirilli (spirillus, singular), or spiral shaped. You can see a common example of each type of bacteria in Figure 8.10. "
____type of drug used to treat bacterial infections,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,G,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
____organism that causes disease,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,E,An infectious disease is a disease that is caused by a pathogen. A pathogen is an organism or virus that causes disease in another living thing. Pathogens are commonly called germs. Watch this dramatic video for an historic perspective on infectious diseases and their causes:  . MEDIA Click image to the left or use the URL below. URL: 
____spiral-shaped bacterium,(A) agram (B) bspirillus (C) cvector (D) dbacillus (E) epathogen (F) fcoccus (G) gantibiotic,B,"Bacteria come in several different shapes. The different shapes can be seen by examining bacteria under a light microscope. Therefore, its relatively easy to classify them by shape. There are three types of bacteria based on shape: bacilli (bacillus, singular), or rod shaped. cocci (coccus, singular), or sphere shaped. spirilli (spirillus, singular), or spiral shaped. You can see a common example of each type of bacteria in Figure 8.10. "
early adulthood begins at age 16.,(A) true (B) false,B,"Early adulthood starts at age 18 or 21. It continues until the mid-30s. During early adulthood, people are at their physical peak. They are also usually in good health. The ability to have children is greatest during early adulthood, as well. This is the stage of life when most people complete their education. They are likely to begin a career or take a full-time job. Many people also marry and start a family during early adulthood. "
late adulthood begins around age 65.,(A) true (B) false,A,"Late adulthood begins in the mid-60s. It continues until death. This is the stage of life when most people retire from work. They are also likely to reflect on their life. They may focus on their grandchildren. During late adulthood, people are not as physically able. For example, they usually have less muscle and slower reflexes. Their immune system also doesnt work as well as it used to. As a result, they have a harder time fighting diseases like the flu. The risk of developing diseases such as heart disease and cancer continues to rise. Arthritis is also common. In arthritis, joints wear out and become stiff and painful. As many as one in four late adults may develop Alzheimers disease. In this disease, brain changes cause mental abilities to decrease. This family picture shows females in each of the three stages of life. Which stage does each represent? Despite problems such as these, many people remain healthy and active into their 80s or even 90s. Do you want to be one of them? Then adopt a healthy lifestyle now and follow it for life. Doing so will increase your chances of staying healthy and active to an old age. Exercising the body and brain help prevent the physical and mental effects of aging. "
middle adulthood is from about age,(A) 35 to 50 (B) 35 to 65 (C) 30 to 60 (D) 40 to 70,B,"Middle adulthood is the period from the mid-30s to the mid-60s. During this stage of life, people start showing signs of aging. Their hair may thin and slowly turn gray. Their skin develops wrinkles. The risk of serious health problems increases. For example, cardiovascular diseases, cancer, and type 2 diabetes become more common in people of middle age. This is also the stage when many people raise a family and strive to attain career goals. "
"heart disease, cancer, and diabetes become more common during this time.",(A) early adulthood (B) middle adulthood (C) late adulthood (D) any of the above,B,"Middle adulthood is the period from the mid-30s to the mid-60s. During this stage of life, people start showing signs of aging. Their hair may thin and slowly turn gray. Their skin develops wrinkles. The risk of serious health problems increases. For example, cardiovascular diseases, cancer, and type 2 diabetes become more common in people of middle age. This is also the stage when many people raise a family and strive to attain career goals. "
"during this time, brain changes cause mental abilities to decrease.",(A) early adulthood (B) middle adulthood (C) late adulthood (D) any of the above,C,"Alzheimers disease is another disease that occurs mainly in older adults. In Alzheimers disease, a person gradually loses most normal mental functions. The patient typically suffers from increasing memory loss, confusion, and mood swings. The cause of Alzheimers isnt known for certain, but it appears to be associated with certain abnormal changes in the brain. There is no known cure for this devastating disease, but medicines may be able to slow its progression. "
"during this time, most people complete their education.",(A) early adulthood (B) middle adulthood (C) late adulthood (D) any of the above,A,"Early adulthood refers to the 20s and early 30s. During early adulthood, most people are at their physical peak, and they are usually in good health. Often, they are completing their education and getting established in the workforce. Many people become engaged or marry during this time. "
"during this time, people have a harder time fighting diseases like the flu.",(A) early adulthood (B) middle adulthood (C) late adulthood (D) any of the above,C,"Getting the recommended vaccinations can help prevent diseases, such as whooping cough and flu. In fact, a yearly flu vaccine is recommended for everyone who is at least 6 months of age. The flu vaccine is especially important for people who are at high risk of developing serious complications (like pneumonia) if they get sick with the flu. People who have certain medical conditions including asthma, diabetes, and chronic lung disease, pregnant women, and people younger than 5 years (and especially those younger than 2), and people 65 years and older should also make sure they get the yearly flu vaccine. Seeking medical help for diseases like asthma can help stop the disease from getting worse. If you are unsure if you should go to the doctor, call the doctors office and ask. "
aquatic biomes in the ocean are called marine biomes.,(A) true (B) false,A,"Aquatic biomes in the ocean are called marine biomes. Organisms that live in marine biomes must be adapted to the salt in the water. For example, many have organs for excreting excess salt. Marine biomes include the oceans, coral reefs, and estuaries ( Figure 1.1). The oceans are the largest of all the ecosystems. They can be divided into four separate zones based on the amount of sunlight. Ocean zones are also divided based on their depth and their distance from land. Each zone has a great diversity of species. Within a coral reef, the dominant organisms are corals. Corals consist partially of algae, which provide nutrients via photosynthesis. Corals also extend tentacles to obtain plankton from the water. Coral reefs include several species of microorganisms, invertebrates, fishes, sea urchins, octopuses, and sea stars. Estuaries are areas where freshwater streams or rivers merge with the ocean. An example of a marine biome, a kelp for- est, from Anacapa Island in the Channel Islands National Marine Sanctuary. "
wetlands may be either freshwater or salt water biomes.,(A) true (B) false,B,"Freshwater biomes are defined by their low salt concentration, usually less than 1%. Plants and animals in freshwater regions are adjusted to the low salt content and would not be able to survive in areas of high salt concentration, such as the ocean. There are different types of freshwater biomes: ponds and lakes ( Figure 1.2), streams and rivers, and wetlands. Ponds and lakes range in size from just a few square meters to thousands of square kilometers. Streams and rivers are bodies of flowing water moving in one direction. They can be found everywhere. They get their starts at headwaters, which may be springs, melting snow, or even lakes, and then travel all the way to their mouths, emptying into another water channel or the ocean. Wetlands are areas of standing water that support aquatic plants. Wetlands include marshes, swamps, and bogs. Lake Tahoe in Northern California is a freshwater biome. "
how are aquatic biomes defined?,(A) By the amount of sunlight (B) their depth and their distance from land (C) b By the aquatic organisms that inhabit the biome (D) c By the salt concentration of the water (E) d all of the above,A,"Recall that terrestrial biomes are defined by their climate. Thats because plants and animals are adapted for certain amounts of temperature and moisture. However, would aquatic biomes be classified in the same way? No, that wouldnt make much senseall parts of an aquatic environment have plenty of water. Aquatic biomes can be generally classified based on the amount of salt in the water. Freshwater biomes have less than 1% salt and are typical of ponds and lakes, streams and rivers, and wetlands. Marine biomes have more salt and are characteristic of the oceans, coral reefs, and estuaries. Most aquatic organisms do not have to deal with extremes of temperature or moisture. Instead, their main limiting factors are the availability of sunlight and the concentration of dissolved oxygen and nutrients in the water. "
what area of the ocean will have the most oxygen and nutrients?,(A) An area near the ocean floor far from the shore (B) An area near the surface and close to the shore (C) An area near the surface in the middle of the ocean (D) An area near the surface and close to the ocean floor in the middle of the ocean,B,"Water in lakes and the ocean also varies in the amount of dissolved oxygen and nutrients it contains: 1. Water near the surface of lakes and the ocean usually has more dissolved oxygen than does deeper water. This is because surface water absorbs oxygen from the air above it. 2. Water near shore generally has more dissolved nutrients than water farther from shore. This is because most nutrients enter the water from land. They are carried by runoff, streams, and rivers that empty into a body of water. 3. Water near the bottom of lakes and the ocean may contain more nutrients than water closer to the surface. When aquatic organisms die, they sink to the bottom. Decomposers near the bottom of the water break down the dead organisms and release their nutrients back into the water. "
photosynthesis occurs in the,(A) photosynthesis zone (B) aphotic zone (C) photic zone (D) sunlight zone,C,"Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced. Chloroplasts contain stacks of thylakoids, which are flattened sacs of membrane. Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids ( Figure 1.1). The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. The chloroplast is the photosynthesis fac- tory of the plant. "
why are estuaries considered marine biomes?,(A) Because sea urchins (B) octopuses (C) and sea stars live there (D) b Because there is a salt concentration greater than freshwater biomes (E) c Because these are places where freshwater streams or rivers merge with the ocean (F) d all of the above,B,"Aquatic biomes in the ocean are called marine biomes. Organisms that live in marine biomes must be adapted to the salt in the water. For example, many have organs for excreting excess salt. Marine biomes include the oceans, coral reefs, and estuaries ( Figure 1.1). The oceans are the largest of all the ecosystems. They can be divided into four separate zones based on the amount of sunlight. Ocean zones are also divided based on their depth and their distance from land. Each zone has a great diversity of species. Within a coral reef, the dominant organisms are corals. Corals consist partially of algae, which provide nutrients via photosynthesis. Corals also extend tentacles to obtain plankton from the water. Coral reefs include several species of microorganisms, invertebrates, fishes, sea urchins, octopuses, and sea stars. Estuaries are areas where freshwater streams or rivers merge with the ocean. An example of a marine biome, a kelp for- est, from Anacapa Island in the Channel Islands National Marine Sanctuary. "
which statement is characteristic of streams and rivers?,(A) They are bodies of flowing water moving in one direction (B) They start at headwaters and empty into another body of water (C) They can be found everywhere (D) all of the above,D,"All streams and rivers have several features in common. These features are shown in (Figure 13.5). The place where a stream or river starts is its source. The source might be a spring, where water flows out of the ground. Or the source might be water from melting snow on a mountain top. A single stream may have multiple sources. A stream or river probably ends when it flows into a body of water, such as a lake or an ocean. A stream ends at its mouth. As the water flows into the body of water, it slows down and drops the sediment it was carrying. The sediment may build up to form a delta. Several other features of streams and rivers are also shown in Figure 13.5. Small streams often flow into bigger streams or rivers. The small streams are called tributaries. A river and all its tributaries make up a river system. At certain times of year, a stream or river may overflow its banks. The area of land that is flooded is called the floodplain. The floodplain may be very wide where the river flows over a nearly flat surface. A river flowing over a floodplain may wear away broad curves. These curves are called meanders. "
aids is an autoimmune disease.,(A) true (B) false,B,"AIDS is not really a single disease. It is a set of symptoms and other diseases. It results from years of damage to the immune system by HIV. AIDS occurs when helper T cells fall to a very low level, making it difficult for the affected person to fight various diseases and other infections. These people develop infections or cancers that people with a healthy immune systems can easily resist. These diseases are usually the cause of death of people with AIDS. The first known cases of AIDS occurred in 1981. Since then, AIDS has led to the deaths of more than 35 million people worldwide. Many of them were children. The greatest number of deaths occurred in Africa. It is also where medications to control HIV are least available. There are currently more people infected with HIV in Africa than any other part of the world. Well over 30 million people are living with HIV worldwide. "
people can die from an allergic reaction.,(A) true (B) false,A,"An allergy occurs when the immune system attacks a harmless substance that enters the body from the outside. A substance that causes an allergy is called an allergen. It is the immune system, not the allergen, that causes the symptoms of an allergy. Did you ever hear of hay fever? Its not really a fever at all. Its an allergy to plant pollens. People with this type of allergy have symptoms such as watery eyes, sneezing, and a runny nose. A common cause of hay fever is the pollen of ragweed. Many people are also allergic to poison ivy ( Figure 1.2). Skin contact with poison ivy leads to an itchy rash in people who are allergic to the plant. Ragweed is a common roadside weed found throughout the United States. Many people are allergic to its pollen. Some people are allergic to certain foods. Nuts and shellfish are common causes of food allergies. Other common causes of allergies include: Drugs, such as penicillin. Mold. Dust. The dead skin cells of dogs and cats, called dander. Stings of wasps and bees. Most allergies can be treated with medicines. Medicines used to treat allergies include antihistamines and corticos- teroids. These medicines help control the immune system when it attacks an allergen. Sometimes, allergies cause severe symptoms, a condition known as anaphylaxis. For example, they may cause the throat to swell so it is hard to breathe. Severe allergies may be life threatening. They require emergency medical care. "
hay fever is an allergy to,(A) hay (B) plant pollens (C) dust (D) mold,B,"An allergy is a disorder in which the immune system responds to a harmless substance as though it was a pathogen. Any substance that causes an allergy is called an allergen. The most common allergens are pollen, dust mites, mold, animal dander, insect stings, latex, and certain foods and medications. To see in greater detail how allergies occur, watch this animated video:  . MEDIA Click image to the left or use the URL below. URL:  Did you ever hear of hay fever? Its not really a fever, and it may have nothing to do with hay. Its actually an allergy to plant pollens. People with this type of allergy generally have seasonal allergies that come back year after year. Symptoms commonly include watery eyes and nasal congestion. Ragweed, shown blooming in Figure 21.8, causes more pollen allergies than any other plant. Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune systems response. Often, allergy symptoms can be prevented. One way is to avoid exposure to the allergens that cause your symptoms. If you are allergic to pollen, for example, you can reduce your exposure by staying inside when pollen levels are highest. Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens. After many months or years of shots, the immune system gets used to the allergens and no longer reacts to them. "
multiple sclerosis is an autoimmune disease in which the immune system attacks,(A) nerve cells (B) muscle cells (C) the joints (D) brain cells,A,"An autoimmune disease is a disease in which the immune system attacks the bodys own cells. Why this happens is not known for certain, but a combination of genetic and environmental factors are likely to be responsible. Type 1 diabetes is an example of an autoimmune disease. In this case, the immune system attacks cells of the pancreas. Two other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain that gradually get worse over time. In rheumatoid arthritis, the immune system attacks joints. This causes joint damage and pain. These diseases cant be prevented and have no known cure. However, they can be treated with medicines that weaken the immune systems attack on normal cells. "
common allergies include allergies to,(A) certain medicines (B) nuts and shellfish (C) dander (D) all of the above,D,"An allergy is a disorder in which the immune system responds to a harmless substance as though it was a pathogen. Any substance that causes an allergy is called an allergen. The most common allergens are pollen, dust mites, mold, animal dander, insect stings, latex, and certain foods and medications. To see in greater detail how allergies occur, watch this animated video:  . MEDIA Click image to the left or use the URL below. URL:  Did you ever hear of hay fever? Its not really a fever, and it may have nothing to do with hay. Its actually an allergy to plant pollens. People with this type of allergy generally have seasonal allergies that come back year after year. Symptoms commonly include watery eyes and nasal congestion. Ragweed, shown blooming in Figure 21.8, causes more pollen allergies than any other plant. Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune systems response. Often, allergy symptoms can be prevented. One way is to avoid exposure to the allergens that cause your symptoms. If you are allergic to pollen, for example, you can reduce your exposure by staying inside when pollen levels are highest. Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens. After many months or years of shots, the immune system gets used to the allergens and no longer reacts to them. "
inflammatory bowel disease is a severe autoimmune disease in which the immune system damages,(A) the stomach (B) the bladder (C) the digestive tract (D) the kidney,C,"Does it make sense for an immune system to attack the cells it is meant to protect? No, but an immune system that does not function properly will attack its own cells. An autoimmune disease is a disease in which the immune system attacks the bodys own cells. One example is type 1 diabetes. In this disease, the immune system attacks cells of the pancreas. Other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain. In rheumatoid arthritis, the immune system attacks the cells of joints. This causes joint damage and pain. Autoimmune diseases cannot be cured. But they can be helped with medicines that weaken the immune systems attack on normal cells. Other autoimmune diseases include celiac disease (damages to the small intestine), inflam- matory bowel disease (damage to the digestive tract), psoriasis (damage to the skin), and lupus (damage to the joints, skin, kidneys, heart, and lungs). "
autoimmune diseases can be cured with,(A) diet changes (B) specific medicines (C) regular exercise (D) Autoimmune diseases cannot be cured,D,"An autoimmune disease is a disease in which the immune system attacks the bodys own cells. Why this happens is not known for certain, but a combination of genetic and environmental factors are likely to be responsible. Type 1 diabetes is an example of an autoimmune disease. In this case, the immune system attacks cells of the pancreas. Two other examples are multiple sclerosis and rheumatoid arthritis. In multiple sclerosis, the immune system attacks nerve cells. This causes weakness and pain that gradually get worse over time. In rheumatoid arthritis, the immune system attacks joints. This causes joint damage and pain. These diseases cant be prevented and have no known cure. However, they can be treated with medicines that weaken the immune systems attack on normal cells. "
there are more bacterial cells in your body than human cells.,(A) true (B) false,A,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
"there could be as many as 1,000 species of bacteria in your digestive system.",(A) true (B) false,A,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
which bacteria help us digest plant food?,(A) Lactobacillus (B) Bacteroides (C) coli (D) probiotic bacteria,B,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
bacteria live in all areas of the gastrointestinal tract except the,(A) large intestine (B) small intestine (C) stomach (D) mouth,C,"Your large intestine is not just made up of cells. It is also an ecosystem, home to trillions of bacteria known as the ""gut flora"" ( Figure 1.1). But dont worry, most of these bacteria are helpful. Friendly bacteria live mostly in the large intestine and part of the small intestine. The acidic environment of the stomach does not allow bacterial growth. Gut bacteria have several roles in the body. For example, intestinal bacteria: Produce vitamin B12 and vitamin K. Control the growth of harmful bacteria. Break down poisons in the large intestine. Break down some substances in food that cannot be digested, such as fiber and some starches and sugars. Bacteria produce enzymes that digest carbohydrates in plant cell walls. Most of the nutritional value of plant material would be wasted without these bacteria. These help us digest plant foods like spinach. Your intestines are home to trillions of bacteria. A wide range of friendly bacteria live in the gut. Bacteria begin to populate the human digestive system right after birth. Gut bacteria include Lactobacillus, the bacteria commonly used in probiotic foods such as yogurt, and E. coli bacteria. About a third of all bacteria in the gut are members of the Bacteroides species. Bacteroides are key in helping us digest plant food. It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet. The bacteria in your digestive system are from anywhere between 300 and 1000 species. As these bacteria are helpful, your body does not attack them. They actually appear to the bodys immune system as cells of the digestive system, not foreign invaders. The bacteria actually cover themselves with sugar molecules removed from the actual cells of the digestive system. This disguises the bacteria and protects them from the immune system. As the bacteria that live in the human gut are beneficial to us, and as the bacteria enjoy a safe environment to live, the relationship that we have with these tiny organisms is described as mutualism, a type of symbiotic relationship. Lastly, keep in mind the small size of bacteria. Together, all the bacteria in your gut may weight just about 2 pounds. "
why are gut bacteria not attacked by the host immune system?,(A) Because the bacteria appear as digestive system cells (B) Because the bacteria are covered sugars produced by the digestive system cells (C) Because the immune system does not see these cells as foreign (D) all of the above,D,"Your large intestine is not just made up of cells. It is also an ecosystem, home to trillions of bacteria known as the ""gut flora"" ( Figure 1.1). But dont worry, most of these bacteria are helpful. Friendly bacteria live mostly in the large intestine and part of the small intestine. The acidic environment of the stomach does not allow bacterial growth. Gut bacteria have several roles in the body. For example, intestinal bacteria: Produce vitamin B12 and vitamin K. Control the growth of harmful bacteria. Break down poisons in the large intestine. Break down some substances in food that cannot be digested, such as fiber and some starches and sugars. Bacteria produce enzymes that digest carbohydrates in plant cell walls. Most of the nutritional value of plant material would be wasted without these bacteria. These help us digest plant foods like spinach. Your intestines are home to trillions of bacteria. A wide range of friendly bacteria live in the gut. Bacteria begin to populate the human digestive system right after birth. Gut bacteria include Lactobacillus, the bacteria commonly used in probiotic foods such as yogurt, and E. coli bacteria. About a third of all bacteria in the gut are members of the Bacteroides species. Bacteroides are key in helping us digest plant food. It is estimated that 100 trillion bacteria live in the gut. This is more than the human cells that make up you. It has also been estimated that there are more bacteria in your mouth than people on the planet. There are over 7 billion people on the planet. The bacteria in your digestive system are from anywhere between 300 and 1000 species. As these bacteria are helpful, your body does not attack them. They actually appear to the bodys immune system as cells of the digestive system, not foreign invaders. The bacteria actually cover themselves with sugar molecules removed from the actual cells of the digestive system. This disguises the bacteria and protects them from the immune system. As the bacteria that live in the human gut are beneficial to us, and as the bacteria enjoy a safe environment to live, the relationship that we have with these tiny organisms is described as mutualism, a type of symbiotic relationship. Lastly, keep in mind the small size of bacteria. Together, all the bacteria in your gut may weight just about 2 pounds. "
what is a role of digestive system bacteria?,(A) Break down fibers and some starches (B) Break down poisons in the stomach (C) Control the growth of helpful bacteria (D) All of the above are roles of digestive system bacteria,A,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
there are some plant foods that we cannot digest on our own. how do bacteria help us digest these foods?,(A) Bacteria produce enzymes that digest proteins in plant cells (B) Bacteria produce enzymes that digest lipids in plant cell walls (C) Bacteria produce enzymes that digest carbohydrates in plant cell walls (D) Bacteria produce enzymes that digest carbohydrates in plant cell membranes,C,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
photosynthetic bacteria evolved before photosynthetic plants.,(A) true (B) false,A,"The earliest life forms did not have the ability to photosynthesize. Without photosynthesis what did the earliest cells eat? Most likely they absorbed the nutrients that floated around in the organic soup that surrounded them. After hundreds of millions of years, these nutrients would have become less abundant. Sometime around 3 billion years ago (about 1.5 billion years after Earth formed!), photosynthesis began. Photo- synthesis allowed organisms to use sunlight and inorganic molecules, such as carbon dioxide and water, to create chemical energy that they could use for food. To photosynthesize, a cell needs chloroplasts (Figure 1.3). A diagram of a bacterium. Chloroplasts are visible in these cells found within a moss. "
mutualistic bacteria kill their prey.,(A) true (B) false,B,"Some bacteria depend on other organisms for survival. For example, some bacteria live in the roots of legumes, such as pea plants ( Figure 1.1). The bacteria turn nitrogen-containing molecules into nitrogen that the plant can use. Meanwhile, the root provides nutrients to the bacteria. In this relationship, both the bacteria and the plant benefit, so it is known as a mutualism. Other mutualistic bacteria include gut microbes. These are bacteria that live in the intestines of animals. They are usually beneficial bacteria, needed by the host organism. These microbes obviously dont kill their host, as that would kill the bacteria as well. "
nitrogen gas in the atmosphere has a strong bond that cannot be broken by many organisms. instead bacteria break the bond so other organisms have access to the nitrogen. organisms need nitrogen to make,(A) food (B) organelles (C) DNA (D) cells,C,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
"what type of bacteria lives in the roots of legumes, such as pea plants?",(A) photosynthetic (B) mutualistic (C) decomposer (D) herbivore,B,"Some bacteria depend on other organisms for survival. For example, some bacteria live in the roots of legumes, such as pea plants ( Figure 1.1). The bacteria turn nitrogen-containing molecules into nitrogen that the plant can use. Meanwhile, the root provides nutrients to the bacteria. In this relationship, both the bacteria and the plant benefit, so it is known as a mutualism. Other mutualistic bacteria include gut microbes. These are bacteria that live in the intestines of animals. They are usually beneficial bacteria, needed by the host organism. These microbes obviously dont kill their host, as that would kill the bacteria as well. "
what do decomposers obtain from the material they break down?,(A) carbon (B) nutrients (C) energy (D) all of the above,D,"Bacteria known as decomposers break down wastes and dead organisms into smaller molecules. These bacteria use the organic substrates they break down to get their energy, carbon, and nutrients they need for survival. "
which of the following is a photosynthetic bacterium?,(A) Staphylococcus aureus (B) Escherichia coli (C) cyanobacteria (D) lactobacilli,C,"Photosynthetic bacteria use the energy of the sun to make their own food. In the presence of sunlight, carbon dioxide and water are turned into glucose and oxygen. The glucose is then turned into usable energy. Glucose is like the ""food"" for the bacteria. An example of photosynthetic bacteria is cyanobacteria, as seen in the opening image. These bacteria are sometimes called blue-green algae, although they are not algae, due to their numerous chlorophyll molecules. "
the nitrogen cycle is the biogeochemical cycle that recycles nitrogen through ecosystems. which two types of bacteria are involved in the nitrogen cycle?,(A) photosynthetic and chemotrophic (B) decomposers and photosynthetic (C) mutualistic and photosynthetic (D) mutualistic and chemotrophic,D,"Nitrogen is another common element found in living things. It is needed to form both proteins and nucleic acids such as DNA. Nitrogen gas makes up 78 percent of Earths atmosphere. In the nitrogen cycle, nitrogen flows back and forth between the atmosphere and living things. You can see how it happens in Figure 24.10. Several different types of bacteria play major roles in the cycle. Animals get nitrogen by eating plants or other organisms that eat plants. Where do plants get nitrogen? They cant use nitrogen gas in the air. The only form of nitrogen that plants can use is in chemical compounds called nitrates. Plants absorb nitrates through their roots. This is called assimilation. Most of the nitrates are produced by bacteria that live in soil or in the roots of plants called legumes. Nitrogen-fixing bacteria change nitrogen gas from the atmosphere to nitrates in soil. When organisms die and decompose, their nitrogen is returned to the soil as ammonium ions. Nitrifying bacteria change some of the ammonium ions into nitrates. The other ammonium ions are changed into nitrogen gas by denitrifying bacteria. "
the first line of defense keeps most pathogens out of the body.,(A) true (B) false,A,"Your bodys first line of defense is like a castles moat and walls. It keeps most pathogens out of your body. The first line of defense includes physical, chemical, and biological barriers. "
the skin is a mucous membrane.,(A) true (B) false,B,"The skin is a very important barrier to pathogens. The skin is the bodys largest organ. In adults, it covers an area of about 16 to 22 square feet! The skin is also the bodys most important defense against disease. It forms a physical barrier between the body and the outside world. The skin has several layers that stack on top of each other ( Figure The mouth and nose are not lined with skin. Instead, they are lined with mucous membranes. Other organs that are exposed to the outside world, including the lungs and stomach, are also lined with mucous membranes. Mucous membranes are not tough like skin, but they have other defenses. One defense of mucous membranes is the mucus they release. Mucus is a sticky, moist substance that covers mucous membranes. Most pathogens get stuck in the mucus before they can do harm to the body. Many mucous membranes also have cilia. Cilia in the lungs are pictured below ( Figure 1.2). Cilia are tiny finger-like projections. They move in waves and sweep mucus and trapped pathogens toward body openings. When you clear your throat or blow your nose, you remove mucus and pathogens from your body. "
which of the following are covered with mucous membranes?,(A) the lining of the mouth (B) the lining of the throat (C) the inside of the lungs (D) all of the above,D,"The skin is a very important barrier to pathogens. The skin is the bodys largest organ. In adults, it covers an area of about 16 to 22 square feet! The skin is also the bodys most important defense against disease. It forms a physical barrier between the body and the outside world. The skin has several layers that stack on top of each other ( Figure The mouth and nose are not lined with skin. Instead, they are lined with mucous membranes. Other organs that are exposed to the outside world, including the lungs and stomach, are also lined with mucous membranes. Mucous membranes are not tough like skin, but they have other defenses. One defense of mucous membranes is the mucus they release. Mucus is a sticky, moist substance that covers mucous membranes. Most pathogens get stuck in the mucus before they can do harm to the body. Many mucous membranes also have cilia. Cilia in the lungs are pictured below ( Figure 1.2). Cilia are tiny finger-like projections. They move in waves and sweep mucus and trapped pathogens toward body openings. When you clear your throat or blow your nose, you remove mucus and pathogens from your body. "
what is a characteristic of the stomach?,(A) The stomach is lined with cilia (B) which help remove pathogens (C) b The stomach releases acid (D) which kills pathogens (E) c The stomach is full of enzymes that kill bacteria (F) d all of the above,B,"The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls that contract and relax to squeeze and mix food. This helps break the food into smaller pieces. It also helps mix the food with enzymes and other secretions in the stomach. For example, the stomach secretes the enzyme pepsin, which helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the lining of the stomach. However, most substances must undergo further digestion in the small intestine before they can be absorbed. The stomach stores the partly digested food until the small intestine is empty. Then a sphincter between the stomach and small intestine relaxes, allowing food to enter the small intestine. "
how do you think the flow of urine is involved in protection?,(A) Your urine flow flushes out pathogens from the bladder area (B) Mucous in your urine removes pathogens (C) Cilia in urine help remove pathogens (D) all of the above,A,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
what is a chemical defense associated with the first line?,(A) the enzyme lysozyme (B) bacteria on the skin (C) the skin itself (D) all of the above,A,"Your bodys first line of defense is like a castles moat and walls. It keeps most pathogens out of your body. The first line of defense includes physical, chemical, and biological barriers. "
what is a physical barrier associated with the first line?,(A) tenzymes in sweat (B) tears (C) and saliva (D) b hydrochloric acid (E) c the skin itself (F) d all of the above,C,"Your bodys first line of defense is like a castles moat and walls. It keeps most pathogens out of your body. The first line of defense includes physical, chemical, and biological barriers. "
blood type is based on what is on the surface of a red blood cell.,(A) true (B) false,A,"The second most important blood group system in human blood is the Rhesus (Rh) factor. A person either has, or does not have, the Rh antigen on the surface of their RBCs. If they do have it, then the person is positive. If the person does not have the antigen, they are considered negative. "
markers inside a red blood cell can trigger an immune response.,(A) true (B) false,B,"Red blood cells carry proteins called antigens on their surface. People may vary in the exact antigens their red blood cells carry. The specific proteins are controlled by the genes they inherit from their parents. The particular antigens you inherit determine your blood type. Why does your blood type matter? Blood type is important for medical reasons. A patient cant safely receive a transfusion of blood containing antigens not found in the patients own blood. With foreign antigens, the transfused blood will be rejected by the persons immune system. This causes a reaction in the patients bloodstream, called agglutination. The transfused red blood cells clump together, as shown in Figure 18.9. The clumped cells block blood vessels and cause other life-threatening problems. There are many sets of antigens that determine different blood types. Two of the best known are the ABO and Rhesus antigens. Both are described below. You can also learn more about them by watching this video: "
what antibody do people with type ab blood produce?,(A) anti-A antibodies (B) anti-B antibodies (C) They do not produce either anti-A or anti-B antibodies (D) anti-O antibodies,C,"Do you know what your blood type is? Maybe you have heard people say that they have type A or type O blood. Blood type is a way to describe the type of antigens, or proteins, on the surface of red blood cells (RBCs). There are four blood types; A, B, AB, and O. 1. Type A blood has type A antigens on the RBCs in the blood. 2. Type AB blood has A and B antigens on the RBCs. 3. Type B has B antigens on the RBCs. 4. Type O does not have either A or B antigens. The ABO blood group system is important if a person needs a blood transfusion. A blood transfusion is the process of putting blood or blood products from one person into the circulatory system of another person. The blood type of the recipient needs to be carefully matched to the blood type of the donor. Thats because different blood types have different types of antibodies, or proteins, released by the blood cells. Antibodies attack strange substances in the body. This is a normal part of your immune response, which is your defense against disease. For example, imagine a person with type O blood was given type A blood. First, what type of antibodies do people with type O blood produce? They produce anti-A and anti-B antibodies. This means, if a person with type O blood received type A blood, the anti-A antibodies in the persons blood would attack the A antigens on the RBCs in the donor blood ( Figure 1.1). The antibodies would cause the RBCs to clump together, and the clumps could block a blood vessel. This clumping of blood cells could cause death. A person with type O blood has A and B antibodies in his/her plasma; if the person was to get type A blood instead of type O, his/her A antibodies would attach to the antigens on the RBCs and cause them to clump together. People with type A blood produce anti-B antibodies, and people with type B blood produce anti-A antibodies. People with type AB blood do not produce either antibody. "
a person with blood type a can receive blood from,(A) A only (B) A and O (C) A and B (D) O only,B,"Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O "
a person with blood type ab can receive blood from,(A) AB only (B) A and B (C) AB and O (D) A (E) B (F) AB and O,C,"Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O "
a person with blood type b can donate blood to types,(A) B only (B) B and AB (C) O only (D) B and O,B,"Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O "
a person with blood type o can donate blood to types,(A) O only (B) A and B (C) AB only (D) A (E) B (F) AB and O,D,"Recall that people with type O blood do not have any antigens on their RBCs. As a result, type O blood can be given to people with blood types A, B, or AB. If there are no antigens on the RBCs, there cannot be an antibody reaction in the blood. People with type O blood are often called universal donors. The blood plasma of AB blood does not contain any anti-A or anti-B antibodies. People with type AB blood can receive any ABO blood type. People with type AB blood are called universal recipients because they can receive any blood type. The antigens and antibodies that define blood type are listed as follows ( Table 1.1). Blood Type Antigen Type Plasma Antibodies A B AB O A B A and B none anti-B anti-A none anti-A, anti-B Can Receive Blood from Types A,O B,O AB, A, B, O O Can Donate Blood to Types A, AB B, AB AB AB, A, B, O "
arteries return blood-rich oxygen to the heart.,(A) true (B) false,B,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
all arteries carry oxygen-rich blood.,(A) true (B) false,B,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
what is the name of the largest artery?,(A) the pulmonary artery (B) the aorta (C) the superior artery (D) the big artery,B,"There are three major types of blood vessels: arteries, veins, and capillaries. You can see each type in Figure 18.5. You can watch a good video introduction to the three types at this link:  MEDIA Click image to the left or use the URL below. URL:  Arteries are muscular blood vessels that carry blood away from the heart. They have thick walls that can withstand the pressure of blood pumped by the heart. Arteries generally carry oxygen-rich blood. The largest artery is the aorta, which receives blood directly from the heart. It branches to form smaller and smaller arteries throughout the body. The smallest arteries are called arterioles. Veins are blood vessels that carry blood toward the heart. This blood is no longer under pressure, so veins have thinner walls. To keep the blood moving, many veins have valves that prevent the backflow of blood. Veins generally carry oxygen-poor blood. The smallest veins are called venules. They merge to form larger and larger veins. The largest vein is the inferior vena cava, which carries blood from the lower body directly to the heart. Capillaries are the smallest type of blood vessels. They connect the smallest arteries (arterioles) and veins (venules). Exchange of substances between cells and the blood takes place across the walls of capillaries, which may be only one cell thick. "
what is the name of the valve between the right ventricle and the pulmonary artery?,(A) tricuspid valve (B) aortic valve (C) pulmonary valve (D) mitral valve,C,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
which occurs during the pulmonary cycle?,(A) Red blood cells release carbon dioxide and pick up oxygen (B) Oxygen-poor leaves the right ventricle through the pulmonary arteries (C) Oxygen-rich blood returns to the heart through the pulmonary veins (D) All of the above are part of the pulmonary cycle,D,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
where does gas exchange occur?,(A) Gas exchange occurs between cells and the blood across the thin walls of (B) Gas exchange occurs between cells and the blood across veins and arteries (C) Gas exchange occurs between cells and the blood across the pulmonary artery (D) all of the above,A,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
which blood vessel returns oxygen from the body to the heart?,(A) the superior vena cava (B) the inferior vena cava (C) the aorta (D) the inferior artery,B,"There are specific veins and arteries that are more significant than others. The pulmonary arteries carry oxygen- poor blood away from the heart to the lungs. These are the only arteries that carry oxygen-poor blood. The aorta is the largest artery in the body. It carries oxygen-rich blood away from the heart. Further away from the heart, the aorta branches into smaller arteries, which eventually branch into capillaries. Capillaries are the smallest type of blood vessel; they connect very small arteries and veins. Gases and other substances are exchanged between cells and the blood across the very thin walls of capillaries. The veins that return oxygen-poor blood to the heart are the superior vena cava and the inferior vena cava. The pulmonary veins return oxygen-rich blood from the lungs to the heart. The pulmonary veins are the only veins that carry oxygen-rich blood. "
most vertebrates are bony fish.,(A) true (B) false,A,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
the lobe-finned fish have fins that seem like appendages.,(A) true (B) false,A,"The lobe-finned fish are characterized by fleshy lobed fins, as opposed to the bony fins of the ray-finned fish. There are two types of living lobe-finned fish: the coelacanths and the lungfish. The pectoral and pelvic fins have joints resembling those of tetrapod (four-limbed land vertebrates) limbs. These fins evolved into legs of amphibians, the first tetrapod land vertebrates. They also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of ray-finned fish. All lobe-finned fishes possess teeth covered with true enamel. The lungfish also possess both gills and lungs, solidifying this class as the ancestors of amphibians. "
amphibians evolved from fish. what type of fish was the ancestor of amphibians?,(A) ray-finned fish (B) lobe-finned fish (C) cartilaginous fish (D) hagfish,B,"The earliest amphibians evolved from a lobe-finned fish ancestor. This occurred about 365 million years ago. Amphibians were the first terrestrial vertebrates. They lived on land as adults, but they had to return to the water to reproduce. The earliest reptiles evolved from an amphibian ancestor. This occurred at least 300 million years ago. Reptiles were the first vertebrates that did not need water to reproduce. Thats because they laid waterproof amniotic eggs. These eggs allowed the embryo inside to breathe without drying out. Mammals and birds both evolved from reptile-like ancestors. The first mammals appeared about 200 million years ago. The earliest birds evolved about 150 million years ago. "
what is the role of the swim bladder?,(A) Allows the fish to breathe without having to swim (B) Stores oxygen that supports the fins (C) Helps the fish create a balance between sinking and floating (D) Stores urine prior to release by the fish,C,"You can see some of the aquatic adaptations of fish in Figure 13.7. For a video introduction to aquatic adaptations of fish, go to this link:  . MEDIA Click image to the left or use the URL below. URL:  Fish are covered with scales. Scales are overlapping tissues, like shingles on a roof. They reduce friction with the water. They also provide a flexible covering that lets fish move their body to swim. Fish have gills. Gills are organs behind the head that absorb oxygen from water. Water enters through the mouth, passes over the gills, and then exits the body. Fish typically have a stream-lined body. This reduces water resistance. Most fish have fins. Fins function like paddles or rudders. They help fish swim and navigate in the water. Most fish have a swim bladder. This is a balloon-like organ containing gas. By inflating or deflating their swim bladder, fish can rise or sink in the water. "
what are the types of living lobe-finned fish?,(A) the long-bodied oarfish and the lungfish (B) the coelacanths and the ocean sunfish (C) the coelacanths and the lungfish (D) the Atlantic blue marlin (E) the black marlin (F) and the sturgeon,C,"The lobe-finned fish are characterized by fleshy lobed fins, as opposed to the bony fins of the ray-finned fish. There are two types of living lobe-finned fish: the coelacanths and the lungfish. The pectoral and pelvic fins have joints resembling those of tetrapod (four-limbed land vertebrates) limbs. These fins evolved into legs of amphibians, the first tetrapod land vertebrates. They also possess two dorsal fins with separate bases, as opposed to the single dorsal fin of ray-finned fish. All lobe-finned fishes possess teeth covered with true enamel. The lungfish also possess both gills and lungs, solidifying this class as the ancestors of amphibians. "
roles of bones in bony fish include which of the following?,(A) for general protection and support (B) as places of attachment for muscles (C) to protect the fish’s brain (D) all of the above,D,"Most fish are bony fish, making them the largest group of vertebrates in existence today. They are characterized by: 1. A head and pectoral girdles (arches supporting the forelimbs) that are covered with bones derived from the skin. 2. A lung or swim bladder, which helps the body create a balance between sinking and floating by either filling up with or emitting gases such as oxygen. Controlling the volume of this organ helps fish control their depth. 3. Jointed, segmented rods supporting the fins. 4. A cover over the gill called the operculum, which helps them breathe without having to swim. 5. The ability to see in color, unlike most other fish. "
most fish are what type?,(A) jawless fish (B) cartilaginous fish (C) ray-finned fish (D) lobe-finned fish,C,"Most vertebrates are ray-finned fish, with close to 27,000 known species. By comparison, there are ""only"" about 10,000 species of birds. The ray-finned fish have fin rays, with fins supported by bony spines known as rays. The ray-finned fish are the dominant class of vertebrates, with nearly 99% of fish falling into this category. They live in all aquatic environments, from freshwater and marine environments from the deep sea to the highest mountain streams. "
cancer is a disease of uncontrolled cell division.,(A) true (B) false,A,"Cancer is a disease that causes cells to divide out of control. Normally, the body has systems that prevent cells from dividing out of control. But in the case of cancer, these systems fail. Cancer is usually caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually happen to genes that control the cell cycle. Because of the mutations, abnormal cells divide uncontrollably. This often leads to the development of a tumor. A tumor is a mass of abnormal tissue. As a tumor grows, it may harm normal tissues around it. Anything that can cause cancer is called a carcinogen. Carcinogens may be pathogens, chemicals, or radiation. "
any mutation can lead to cancer.,(A) true (B) false,B,"Most cancers are caused by mutations. Mutations are random errors in genes. Mutations that lead to cancer usually occur in genes that control the cell cycle. Because of the mutations, abnormal cells are allowed to divide. Some mutations that lead to cancer may be inherited. However, most of the mutations are caused by environmental factors. Anything in the environment that can cause cancer is called a carcinogen. Common carcinogens include certain chemicals and some types of radiation. Many different chemicals can cause cancer. For example, tobacco contains dozens of chemicals, including nicotine, that have been shown to cause cancer. Figure 21.5 shows some of these chemicals. Smoking tobacco or using smokeless tobacco increases the risk of cancer of the lung, mouth, throat, and urinary bladder. Types of radiation that cause cancer include ultraviolet (UV) radiation and radon. UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a naturally occurring radioactive gas that escapes from underground rocks. It may seep into the basements of buildings. It can cause lung cancer. "
warning signs of cancer include,(A) a lump in the breast or elsewhere (B) a persistent cough (C) changes in the color or size of a wart or mole (D) all of the above,D,"Many cases of cancer can be cured if the cancer is diagnosed and treated early. Treatment often involves removing a tumor with surgery. This may be followed by other types of treatments. These treatments may include drugs and radiation, both of which target and kill cancer cells. Its important to know the warning signs of cancer so it can be diagnosed as early as possible. Having warning signs doesnt mean that you have cancer, but you should check with a doctor to be sure. Warning signs of cancer include: a change in bowel or bladder habits. a sore that doesnt heal. unusual bleeding or discharge. a lump in the breast or elsewhere. frequent, long-term indigestion. difficulty swallowing. obvious changes in a wart or mole. persistent cough or hoarseness. "
what is the leading cause of skin caner?,(A) radon (B) UV radiation (C) the human papilloma virus (D) smoking,B,Forms of radiation that cause cancer include ultraviolet (UV) radiation and radon ( Figure 1.3). UV radiation is part of sunlight. It is the leading cause of skin cancer. Radon is a natural radioactive gas that seeps into buildings from the ground. It can cause lung cancer. 
what is the main source of chemical carcinogens?,(A) asbestos (B) nicotine (C) tobacco smoke (D) sunlight,C,"Many different chemical substances cause cancer. Dozens of chemicals in tobacco smoke, including nicotine, have been shown to cause cancer ( Figure 1.2). In fact, tobacco smoke is one of the main sources of chemical carcinogens. Smoking tobacco increases the risk of cancer of the lung, mouth, throat, and bladder. Using smokeless tobacco can also cause cancer. Other chemicals that cause cancer include asbestos, formaldehyde, benzene, cadmium, and nickel. "
smoking tobacco increases the risk of,(A) lung (B) mouth (C) throat (D) and bladder cancer (E) b lung (F) mouth (G) tongue (H) and liver cancer (I) c lung (J) mouth (K) stomach (L) and bone cancer (M) d lung (N) mouth (O) throat (P) and neck cancer,A,"Many different chemical substances cause cancer. Dozens of chemicals in tobacco smoke, including nicotine, have been shown to cause cancer ( Figure 1.2). In fact, tobacco smoke is one of the main sources of chemical carcinogens. Smoking tobacco increases the risk of cancer of the lung, mouth, throat, and bladder. Using smokeless tobacco can also cause cancer. Other chemicals that cause cancer include asbestos, formaldehyde, benzene, cadmium, and nickel. "
what is the most common cancer in children?,(A) blood cancer (B) leukemia (C) skin cancer (D) brain cancer,B,"Cancer occurs most often in adults, especially adults over the age of 50. The most common types of cancer in adults differ between males and females. The most common type of cancer in adult males is cancer of the prostate gland. The prostate gland is part of the male reproductive system. About one third of all cancers in men are prostate cancers. The most common type of cancer in adult females is cancer of the breast. About one third of all cancers in women are breast cancers. In both men and women, the second most common type of cancer is lung cancer. Most cases of lung cancer develop in people who smoke. Childhood cancer is rare. The main type of cancer in children is leukemia. It makes up about one third of all childhood cancers. It occurs when the body makes abnormal white blood cells. "
the heart has coronary arteries that supply it with oxygen.,(A) true (B) false,A,"Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They are known as coronary arteries. Coronary heart disease is the end result of the buildup of plaque within the walls of the coronary arteries. Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain. Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no symptoms for many years until they have a heart attack. A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States. The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the heart muscle to die ( Figure 1.2). Maybe one day stem cells will be used to replace dead cardiac muscle cells. "
currently dead cardiac muscle cannot be replaced.,(A) true (B) false,A,"Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They are known as coronary arteries. Coronary heart disease is the end result of the buildup of plaque within the walls of the coronary arteries. Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain. Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no symptoms for many years until they have a heart attack. A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States. The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the heart muscle to die ( Figure 1.2). Maybe one day stem cells will be used to replace dead cardiac muscle cells. "
risk factors for a stroke include,(A) low blood pressure (B) high cholesterol and smoking (C) b high blood pressure (D) low cholesterol and smoking (E) c high blood pressure (F) high cholesterol and smoking (G) d old age (H) diabetes and cancer,C,"Atherosclerosis in the arteries of the brain can also lead to a stroke. A stroke is a loss of brain function due to a blockage of the blood supply to the brain. Risk factors for stroke include old age, high blood pressure, having a previous stroke, diabetes, high cholesterol, and smoking. The best way to reduce the risk of stroke is to have low blood pressure. "
what are three foods you should eat in small amounts to lower your risk of heart disease?,(A) fresh or frozen fruits and vegetables and lean meats (B) frozen dinners (C) hot dogs and butter (D) c meat (E) eggs and vegetables (F) d vegetable oils (G) dark chocolate and butter,B,"Make at least half your daily grain choices whole grains. Examples of whole grains are whole wheat bread, whole wheat pasta, and brown rice. Choose a variety of different vegetables each day. Be sure to include both dark green vegetables, such as spinach and broccoli, and orange vegetables, such as carrots and sweet potatoes. Choose a variety of different fruits each day. Select mainly fresh fruits rather than canned fruits, and whole fruits instead of fruit juices. When choosing oils, choose unsaturated oils, such as olive oil, canola oil, or vegetable oil. Choose low-fat or fat-free milk and other dairy products. For example, select fat-free yogurt and low-fat cheese. For meats, choose fish, chicken, and lean cuts of beef. Also, be sure to include beans, nuts, and seeds. "
what is atherosclerosis?,(A) inflammation of the walls of arteries that causes swelling and a buildup of (B) inflammation of the walls of veins that causes swelling and a buildup plaque (C) a buildup of plaque (D) inflammation of the walls of arteries,A,"A cardiovascular disease (CVD) is any disease that affects the cardiovascular system. But the term is usually used to describe diseases that are linked to atherosclerosis. Atherosclerosis ( Figure 1.1) is an inflammation of the walls of arteries that causes swelling and a buildup of material called plaque. Plaque is made of cell pieces, fatty substances, calcium, and connective tissue that builds up around the area of inflammation. As a plaque grows, it stiffens and narrows the artery, which decreases the flow of blood through the artery. Atherosclerosis normally begins in late childhood and is typically found in most major arteries. It does not usually have any early symptoms. Causes of atherosclerosis include a high-fat diet, high cholesterol, smoking, obesity, and diabetes. Atherosclerosis becomes a threat to health when the plaque buildup prevents blood circulation in the heart or the brain. A blocked blood vessel in the heart can cause a heart attack. Blockage of the circulation in the brain can cause a stroke. Ways to prevent atherosclerosis include eating healthy foods, getting plenty of exercise and not smoking. These three factors are not as hard to control as you may think. If you smoke, STOP. Start a regular exercise program and watch what you eat. A diet high in saturated fat and cholesterol can raise your cholesterol levels, which makes more plaque available to line artery walls and narrow your arteries. Cholesterol and saturated fats are found mostly in animal products such Atherosclerosis is sometimes referred to as hardening of the arteries; plaque build- up decreases the blood flow through the artery. as meat, eggs, milk, and other dairy products. Check food labels to find the amount of saturated fat in a product. Also, avoid large amounts of salt and sugar. Be careful with processed foods, such as frozen dinners, as they can be high in fat, sugar, salt and cholesterol. Eat lots of fresh or frozen fruits and vegetables, smaller portions of lean meats and fish, and whole grains such as oats and whole wheat. Limit saturated fats like butter, instead choose unsaturated vegetable oils such as canola oil. "
"if cardiac muscle is starved of oxygen for more than _________, it will die.",(A) 1 minute (B) 5 seconds (C) 5 minutes (D) 10 minutes,C,"Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They are known as coronary arteries. Coronary heart disease is the end result of the buildup of plaque within the walls of the coronary arteries. Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain. Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no symptoms for many years until they have a heart attack. A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States. The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the heart muscle to die ( Figure 1.2). Maybe one day stem cells will be used to replace dead cardiac muscle cells. "
plaque is made of,(A) platelets (B) cholesterol (C) calcium and connective tissue (D) b cell pieces and cholesterol (E) c cell pieces (F) fatty substances (G) calcium (H) and connective tissue (I) d sodium (J) calcium (K) fat (L) and tobacco,C,"A lava plateau is made of a large amount of fluid lava. The lava flows over a large area and cools. This creates a large, flat surface of igneous rock. Lava plateaus may be huge. The Columbia Plateau covers over 161,000 square kilometers (63,000 square miles). It makes up parts of the states of Washington, Oregon, and Idaho. Thin, fluid lava created the rock that makes up the entire ocean floor. This is from multiple eruptions from vents at the mid-ocean ridge. While not exactly a lava plateau, its interesting to think about so much lava! "
hormones travel around your body in your blood.,(A) true (B) false,A,"Endocrine hormones travel throughout the body in the blood. However, each endocrine hormone affects only certain cells, called target cells. "
the cardiovascular system removes oxygen from your cells.,(A) true (B) false,B,"Your cardiovascular system has many jobs. At times the cardiovascular system can work like a pump, a heating system, or even a postal carrier. To do these tasks, your cardiovascular system works with other organ systems, such as the respiratory, endocrine, and nervous systems. The cardiovascular system (Figure 1.1) is made up of the heart, the blood vessels, and the blood. It moves nutrients, gases (like oxygen), and wastes to and from your cells. Every cell in your body depends on your cardiovascular system. If your cells dont receive nutrients, they cannot survive. The main function of the cardiovascular system is to deliver oxygen to each of your cells. Blood receives oxygen in your lungs (the main organs of the respiratory system) and then is pumped, by your heart, throughout your body. The oxygen then diffuses into your cells, and carbon dioxide, a waste product of cellular respiration, moves from your cells into your blood to be delivered back to your lungs and exhaled. Each cell in your body needs oxygen, as oxygen is used in cellular respiration to produce energy in the form of ATP. Without oxygen, lactic acid fermentation would occur in your cells, which can only be maintained for a brief period of time. Arteries carry blood full of oxygen (""oxygen-rich"") away from the heart and veins return oxygen-poor blood back to the heart. The cardiovascular system also plays a role in maintaining body temperature. It helps to keep you warm by moving warm blood around your body. Your blood vessels also control your body temperature to keep you from getting too hot or too cold. When your brain senses that your body temperature is increasing, it sends messages to the blood vessels in the skin to increase in diameter. Increasing the diameter of the blood vessels increases the amount of blood and heat that moves near the skins surface. The heat is then released from the skin. This helps you cool down. What do you think your blood vessels do when your body temperature is decreasing? The blood also carries hormones, which are chemical messenger molecules produced by organs of the endocrine system, through your body. Hormones are produced in one area of your body and have an effect on another area. To get to that other area, they must travel through your blood. An example is the hormone adrenaline, produced by the adrenal glands on top of the kidneys. Adrenaline has multiple effects on the heart (it quickens the heart rate), on muscles and on the airway. "
oxygen diffusing into the blood involves which two organ systems?,(A) the cardiovascular and the endocrine systems (B) the cardiovascular and the respiratory systems (C) the cardiovascular and the nervous systems (D) the endocrine and the respiratory systems,B,"Systemic circulation is the longer loop of the cardiovascular system. It carries blood between the heart and the rest of the body. Oxygen-rich blood flows from the heart to cells throughout the body. As it passes cells, the blood releases oxygen and absorbs carbon dioxide. Then the oxygen-poor blood returns to the heart. "
what is the effect of adrenaline on the heart?,(A) Adrenaline increases the heart rate (B) Adrenaline decreases the heart rate (C) Adrenaline has no effect on the heart rate (D) Adrenaline maintains the heart’s temperature,A,"The heart is a muscular organ in the chest. It consists mainly of cardiac muscle tissue. It pumps blood by repeated, rhythmic contractions. This produces the familiar lub-dub sound of each heartbeat. For a good video introduction to the heart and how it works, watch this entertaining Bill Nye video:  MEDIA Click image to the left or use the URL below. URL: "
which statement describes the movement of oxygen-rich blood?,(A) Veins carry oxygen-rich blood away from the heart (B) Arteries carry oxygen-rich blood away from the heart (C) Arteries carry oxygen-rich blood back to the heart (D) none of the above,B,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
what are examples of cardio activities?,(A) rowing and running (B) biking (C) swimming and skiing (cross-country) (D) All of the above are cardio activities,D,"Aerobic exercises are exercises in which a low to moderate level of exertion can be sustained over long periods. These are exercises that cause your heart to beat faster and allow your muscles to use oxygen to contract. If you exercise aerobically, overtime, your muscles will not get easily tired, and you will use oxygen more efficiently. Aerobic exercise (Figure 1.2) also helps improve cardiac muscle. "
what is the main function of the cardiovascular system?,(A) The main function of the cardiovascular system is to deliver carbon dioxide to each of your cells (B) The main function of the cardiovascular system is to remove oxygen from each of your cells (C) The main function of the cardiovascular system is to deliver oxygen to each (D) The main function of the cardiovascular system is to remove carbon dioxide from each of your cells,C,"The main function of the cardiovascular system is transporting substances around the body. Figure 18.1 shows some of the substances that are transported in the blood. They include hormones, oxygen, nutrients from digested food, and cellular wastes. Transport of all these materials is necessary to maintain homeostasis of the body and life itself. The cardiovascular system also helps regulate body temperature by controlling where blood moves around the body. Blood is warm, so when more blood flows to the surface of the body, it warms the surface. This allows the body to lose excess heat from the surface. When less blood flows to the surface, it cools the surface. This allows the body to conserve heat and stay warm. You can see the role of blood vessels in the regulation of body temperature in this video:  . MEDIA Click image to the left or use the URL below. URL: "
smoking is one of the biggest risk factors for cardiovascular disease.,(A) true (B) false,A,"Cigarette smoking can cause serious diseases, so not smoking or quitting now are the most effective ways to reduce your risk of developing chronic respiratory diseases, such as lung cancer. Avoiding (or stopping) smoking is the single best way to prevent many respiratory and cardiovascular diseases. Also, do your best to avoid secondhand smoke. "
"the older a person is, the greater their chance of developing a cardiovascular disease.",(A) true (B) false,A,"Many factors influence your risk of developing cardiovascular diseases. Some of these factors you cant control. Older age, male gender, and a family history of cardiovascular disease all increase the risk and cant be controlled. However, you can control many other factors. To reduce the risk of cardiovascular disease, you can: avoid smoking. get regular physical activity. maintain a healthy percent of body fat. eat a healthy, low-fat diet. get regular checkups to detect and manage problems such as high blood pressure and high blood cholesterol. "
what is the best way to reduce the risk of heart disease?,(A) having low cholesterol levels (B) getting plenty of exercise (C) not smoking (D) eating properly,C,Diseases of the cardiovascular system are common and may be life threatening. A healthy lifestyle can reduce the risk of such diseases developing. 
poor eating habits can result in,(A) high cholesterol levels (B) cardiovascular disease (C) obesity (D) all of the above,D,"What happens if you dont get enough exercise to balance the food you eat? Any unused energy in the food is stored as fat. If you take in more energy than you use day after day, you will store more and more fat and become overweight. Eventually, you may become obese. Obesity is diagnosed in people who have a high percentage of body fat. A measure called Body Mass Index, or BMI, is often used to diagnose obesity. You can learn more about BMI by watching this video:  MEDIA Click image to the left or use the URL below. URL:  Obesity is associated with many health problems, including high blood pressure and diabetes. People that remain obese during their entire adulthood usually do not live as long as people that stay within a healthy weight range. The current generation of young people in the U.S. is the first generation in our history that may have a shorter life span than their parents because of obesity and the health problems associated with it. "
too much ldl cholesterol can lead to,(A) atherosclerosis (B) a heart attack (C) a stroke (D) all of the above,D,"Cholesterol cant dissolve in the blood. It has to be transported to and from the cells by carriers called lipoproteins. Low-density lipoprotein, or LDL, is known as ""bad"" cholesterol. High-density lipoprotein (HDL) is known as good cholesterol. When too much LDL cholesterol circulates in the blood, it can slowly build up in the inner walls of the The USDAs MyPyramid recommends that you limit the amount of such foods in your diet to occasional treats. arteries that feed the heart and brain. Together with other substances, it can form plaque, and lead to atherosclerosis. If a clot forms and blocks a narrowed artery, a heart attack or stroke can result. Cholesterol comes from the food you eat as well as being made by the body. To lower bad cholesterol, a diet low in saturated fat and dietary cholesterol should be followed. Regular aerobic exercise also lowers LDL cholesterol and increases HDL cholesterol. "
which risk factor strains the cardiovascular system?,(A) high cholesterol levels (B) high blood pressure (C) high tobacco use (D) high age,B,"There are many risk factors that can cause a person to develop cardiovascular disease. A risk factor is anything that is linked to an increased chance of developing a disease. Some of the risk factors for cardiovascular disease you cannot control, but there are many risk factors you can control. Risk factors you cannot control include: Age: The older a person is, the greater their chance of developing a cardiovascular disease. Gender: Men under age 64 are much more likely to die of coronary heart disease than women, although the gender difference decreases with age. Genetics: Family history of cardiovascular disease increases a persons chance of developing heart disease. Risk factors you can control include many lifestyle factors: Tobacco smoking: Giving up smoking or never starting to smoke is the best way to reduce the risk of heart disease. Diabetes: Diabetes can cause bodily changes, such as high cholesterol levels, which are are risk factors for cardiovascular disease. High cholesterol levels: High amounts of ""bad cholesterol,"" increase the risk of cardiovascular disease. Obesity: Having a very high percentage of body fat, especially if the fat is mostly found in the upper body, rather than the hips and thighs, increases risk significantly. High blood pressure: If the heart and blood vessels have to work harder than normal, this puts the cardiovas- cular system under a strain. Lack of physical activity: Aerobic activities, such as the one pictured below ( Figure 1.1), help keep your heart healthy. To reduce the risk of disease, you should be active for at least 60 minutes a day, five days a week. Poor eating habits: Eating mostly foods that do not have many nutrients other than fat or carbohydrate leads to high cholesterol levels, obesity, and cardiovascular disease ( Figure 1.2). 60 minutes a day of vigorous aerobic activity, such as basketball, is enough to help keep your cardiovascular system healthy. "
"to reduce the risk of disease, you should be active for at least",(A) 30 minutes a day (B) three days a week (C) b 30 minutes a day (D) five days a week (E) c 60 minutes a day (F) five days a week (G) d 60 minutes a day (H) three days a week,C,"Physical activity is an important part of balanced eating. It helps you use up any extra Calories in the foods you eat. You should try to get at least an hour of exercise just about every day (see Figure 17.9). Exercise has many health benefits in addition to balancing the energy in food. For example, it strengthens the bones and muscles and may improve your mood. "
the cartilaginous are the first fish with a bony skeleton.,(A) true (B) false,B,"The earliest fish had an endoskeleton made of cartilage rather than bone. They also lacked a complete vertebral column. The first fish with a complete vertebral column evolved about 450 million years ago. These fish had jaws. They may have been similar to living sharks. About 400 million years ago, the first fish with a bony endoskeleton evolved. A bony skeleton could support a bigger body. Early bony fish evolved into modern ray-finned fish and lobe-finned fish. "
the cartilaginous fish are the first fish with jaws.,(A) true (B) false,A,"The 1,000 or so species of cartilaginous fish are subdivided into two subclasses: the first includes sharks, rays, and skates; the second includes chimaera, sometimes called ghost sharks. Fish from this group range in size from the dwarf lanternshark, at 6.3 inches, to the over 50-foot whale shark. Sharks obviously have jaws, as do the other cartilaginous fish. These fish evolved from the jawless fish. So why did fish eventually evolve to have jaws? Such an adaptation would allow fish to eat a much wider variety of food, including plants and other organisms. Other characteristics of cartilaginous fish include: Paired fins. Paired nostrils. Scales. Two-chambered hearts. Skeletons made of cartilage rather than bone. Cartilage is supportive tissue that does not have as much calcium as bones, which makes bones rigid. Cartilage is softer and more flexible than bone. "
which of the following are characteristics of cartilaginous fish?,(A) a two-chamber heart (B) paired fins (C) paired nostrils (D) all of the above,D,"The 1,000 or so species of cartilaginous fish are subdivided into two subclasses: the first includes sharks, rays, and skates; the second includes chimaera, sometimes called ghost sharks. Fish from this group range in size from the dwarf lanternshark, at 6.3 inches, to the over 50-foot whale shark. Sharks obviously have jaws, as do the other cartilaginous fish. These fish evolved from the jawless fish. So why did fish eventually evolve to have jaws? Such an adaptation would allow fish to eat a much wider variety of food, including plants and other organisms. Other characteristics of cartilaginous fish include: Paired fins. Paired nostrils. Scales. Two-chambered hearts. Skeletons made of cartilage rather than bone. Cartilage is supportive tissue that does not have as much calcium as bones, which makes bones rigid. Cartilage is softer and more flexible than bone. "
some sharks have ovoviviparous reproduction. what is ovoviviparous reproduction?,(A) When the egg is laid after fertilization (B) When the egg is laid and fertilized externally (C) When the baby is born alive (D) none of the above,C,"Vertebrates reproduce sexually. Most have separate male and female sexes. Vertebrates have one of three reproduc- tive strategies: ovipary, ovovivipary, or vivipary. Ovipary refers to the development of an embryo within an egg outside the mothers body. This occurs in most fish, amphibians, and reptiles. It also occurs in all birds. Ovovivipary refers to the development of an embryo inside an egg within the mothers body. The egg remains inside the mothers body until it hatches, but the mother provides no nourishment to the developing embryo inside the egg. This occurs in some species of fish and reptiles. Vivipary refers to the development and nourishment of an embryo within the mothers body but not inside an egg. Birth may be followed by a period of parental care of the offspring. This reproductive strategy occurs in almost all mammals including humans. "
what are two ways sharks can be distinguished?,(A) the number of gill slits and the type of teeth (B) the number of fins and their body shape (C) the type of fins and their activity at night (D) All of the above are ways to distinguish sharks,D,"The sharks, rays, and skates (which are similar to stingrays) are further broken into two superorders: 1. Rays and skates. 2. Sharks. Sharks are some of the most frequently studied cartilaginous fish. Sharks are distinguished by such features as: The number of gill slits. The number and type of fins. The type of teeth. The size of their jaws. Body shape. Their activity at night. An elongated, toothed snout used for slashing the fish that they eat, as seen in sawsharks. Teeth used for grasping and crushing shellfish, a characteristic of bullhead sharks. A whisker-like organ named barbels that help sharks find food, a characteristic of carpet sharks. A long snout (or nose-like area), characteristic of groundsharks. Ovoviviparous reproduction, where the eggs develop inside the mothers body after internal fertilization, and the young are born alive. This trait is characteristic of mackerel sharks. All sharks mate by internal fertilization. Some sharks then lay their eggs, others allow internal development. "
what are barbells in sharks?,(A) Muscles around the jaws that allow for rapid contraction (B) Whisker-like organs that help sharks sense predators (C) Whisker-like organs that sense the environment to help the sharks find food (D) Organ that produces red blood cells,C,"The sharks, rays, and skates (which are similar to stingrays) are further broken into two superorders: 1. Rays and skates. 2. Sharks. Sharks are some of the most frequently studied cartilaginous fish. Sharks are distinguished by such features as: The number of gill slits. The number and type of fins. The type of teeth. The size of their jaws. Body shape. Their activity at night. An elongated, toothed snout used for slashing the fish that they eat, as seen in sawsharks. Teeth used for grasping and crushing shellfish, a characteristic of bullhead sharks. A whisker-like organ named barbels that help sharks find food, a characteristic of carpet sharks. A long snout (or nose-like area), characteristic of groundsharks. Ovoviviparous reproduction, where the eggs develop inside the mothers body after internal fertilization, and the young are born alive. This trait is characteristic of mackerel sharks. All sharks mate by internal fertilization. Some sharks then lay their eggs, others allow internal development. "
what is leydigs organ?,(A) The organ that helps sharks and rays sense predators (B) The organ that produces red blood cells (C) The organ that helps sharks and rays find food (D)  (E) d The organ that replaces lost teeth,B,"Since they do not have bone marrow (as they have no bones), red blood cells are produced in the spleen, in special tissue around the reproductive organs, and in an organ called Leydigs organ, only found in cartilaginous fishes. The tough skin of this group of fish is covered with placoid scales, which are hard scales formed from modified teeth. The scales are covered with a hard enamel. The hard covering and the way the scales are arranged, gives the fish skin rough, sandpaper-like feel. The function of these scales is for protection against predators. The shape of sharks teeth differ according to their diet. Species that feed on mollusks and crustaceans have dense flattened teeth for crushing, those that feed on fish have needle-like teeth for gripping, and those that feed on larger prey, such as mammals, have pointed lower teeth for gripping and triangular upper teeth with serrated edges for cutting. Sharks continually shed and replace their teeth, with some shedding as much as 35,000 teeth in a lifetime. "
the main reason you need to eat is to get energy.,(A) true (B) false,A,Your body needs food for three purposes: 1. Food gives the body energy. You need energy for everything you do. The energy in food is measured in a unit called the Calorie. 2. Food provides building materials for the body. The body needs building materials for growth and repair. 3. Food contains substances that help control body processes. Body processes must be kept in balance for good health. 
cellular respiration can be described as the reverse or opposite of photosynthesis.,(A) true (B) false,A,"Cellular respiration and photosynthesis are like two sides of the same coin. This is clear from the diagram in Figure needed for photosynthesis. Together, the two processes store and release energy in virtually all living things. "
which of the following supplies your body with energy?,(A) sunlight (B) food (C) carbon dioxide (D) all of the above,B,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
the process of obtaining energy from food is,(A) photosynthesis (B) cellular respiration (C) glucose (D) ATP,B,"Everything you do takes energy. Energy is the ability to change or move matter. Whether its reading these words or running a sprint, it requires energy. In fact, it takes energy just to stay alive. Where do you get energy? You probably know the answer. You get energy from food. Figure {{ref|MS-LS-SE-02-03-Food|below}] shows some healthy foods that can provide you with energy. Just like you, other living things need a source of energy. But they may use a different source. Organisms may be grouped on the basis of the source of energy they use. In which group do you belong? Producers such as the tree in Figure 2.1 use sunlight for energy to produce their own food. The process is called photosynthesis, and the food is sugar. Plants and other organisms use this food for energy. Consumers such as the raccoon in Figure 2.1 eat plantsor other consumers that eat plantsas a source of energy. Some consumers such as the mushroom in Figure 2.1 get their energy from dead organic matter. For example, they might consume dead leaves on a forest floor. "
which best summarizes cellular respiration?,(A) carbon dioxide + water → glucose + oxygen (B) carbon dioxide + oxygen → glucose + water (C) glucose + water → carbon dioxide + oxygen (D) glucose + oxygen → carbon dioxide + water,D,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
"essentially, what occurs during cellular respiration?",(A) Energy is released from glucose (B) ATP is formed from glucose and oxygen (C) The energy stored in carbon dioxide is converted into glucose (D) The energy stored in glucose is converted into ATP,D,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
which of the following is a polysaccharide?,(A) ATP (B) glucose (C) starch (D) carbon dioxide,C,"Cellulose is another complex carbohydrate that is a polymer of glucose. However, glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers, as you can see in the Figure 1.3. Have you ever eaten raw celery? If you have, then you probably noticed that Foods that are good sources of starches. the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to stems and tree trunks. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. "
"the brain, spinal cord and adjoining nerves make up the central nervous system.",(A) true (B) false,B,"The central nervous system (CNS) ( Figure 1.1) is the largest part of the nervous system. It includes the brain and the spinal cord. The bony skull protects the brain. The spinal cord is protected within the bones of the spine, which are called vertebrae. "
"the brain contains up to 100,000,000,000 neurons.",(A) true (B) false,A,"The human brain is an amazing organ. It is the most complex organ in the human body. By adulthood, the brain weighs about 3 pounds and consists of billions of neurons. All those cells need a lot of energy. In fact, the adult brain uses almost a quarter of the total energy used by the body! The brain serves as the control center of the nervous system and the body as a whole. It lets us understand what we see, hear, or sense in other ways. It allows us to learn, think, remember, and use language. It controls all the organs and muscles in our body. "
"what part of the brain controls breathing, heartbeat, and digestion?",(A) the cerebrum (B) the cerebellum (C) the brain stem (D) the corpus callosum,C,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
what part of the brain controls voluntary movements?,(A) the cerebrum (B) the cerebellum (C) the brain stem (D) the corpus callosum,A,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
which part of the brain controls thinking?,(A) the frontal lobe (B) the parietal lobe (C) the temporal lobe (D) the occipital lobe,A,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
which part of the brain controls the sense of smell?,(A) the frontal lobe (B) the parietal lobe (C) the temporal lobe (D) the occipital lobe,C,"The sense of taste is controlled by sensory neurons on the tongue. They are grouped in bundles called taste buds. You can see taste buds on the tongue in Figure 20.16. Taste neurons sense chemicals in food. They can detect five different tastes: sweet, salty, sour, bitter, and umami, which is a meaty taste. When taste neurons sense chemicals, they send messages to the brain about them. The brain then decides what you are tasting. The sense of smell also involves sensory neurons that sense chemicals. These neurons are found in the nose, and they sense chemicals in the air. Unlike taste neurons, smell neurons can detect thousands of different odors. Your sense of smell plays a big role in your sense of taste. You can use your sense of taste alone to learn that a food is sweet. However, you have to use your sense of smell as well to learn that the food tastes like apple pie. "
what connects the right side of the brain to the left side?,(A) nerves (B) the frontal lobe (C) the brain stem (D) the corpus callosum,D,"The cerebrum is divided down the middle from the front to the back of the head. The two halves of the cerebrum are called the right and left hemispheres. The two hemispheres are very similar but not identical. They are connected to each other by a thick bundle of axons deep within the brain. These axons allow the two hemispheres to communicate with each other. Did you know that the right hemisphere of the cerebrum controls the left side of the body, and vice versa? This can happen because of the connections between the two hemispheres. Each hemisphere is further divided into four parts, called lobes, as you can see in Figure 20.6. Each lobe has different functions. One function of each lobe is listed in the figure. "
the difference between a hydrogen atom and a helium atom is one proton.,(A) true (B) false,A,"All protons are identical. For example, hydrogen protons are exactly the same as protons of helium and all other elements, or pure substances. However, atoms of different elements have different numbers of protons. In fact, atoms of any given element have a unique number of protons that is different from the numbers of protons of all other elements. For example, a hydrogen atom has just one proton, whereas a helium atom has two protons. The number of protons in an atom determines the electrical charge of the nucleus. The nucleus also contains neutrons, but they are neutral in charge. The one proton in a hydrogen nucleus, for example, gives it a charge of +1, and the two protons in a helium nucleus give it a charge of +2. "
matter is anything that takes up space and has mass.,(A) true (B) false,A,"Matter is all the stuff that exists in the universe. Everything you can see and touch is made of matter, including you! The only things that arent matter are forms of energy, such as light and sound. In science, matter is defined as anything that has mass and volume. Mass and volume measure different aspects of matter. "
which of the following is a molecule and a compound?,(A) O2 (B) H2O (C) H2 (D) N2,C,A molecule is the smallest unit of a chemical compound. A compound is a substance made of two or more elements. The elements in a chemical compound are always present in a certain ratio. Water is probably one of the simplest compounds that you know. A water molecule is made of two hydrogen atoms and one oxygen atom (Figure 3.2). All water molecules have the same ratio: two hydrogen atoms to one oxygen atom. 
who developed the periodic table?,(A) Gregor Mendel (B) Dmitri Mendel (C) Charles Darwin (D) Dmitri Mendeleev,B,"In 1869, a Russian scientist named Dmitri Mendeleev created the periodic table, which is a way of organizing elements according to their unique characteristics, like atomic number, density, boiling point, and other values ( Figure 1.2). Each element is represented by a one or two letter symbol. For example, H stands for hydrogen, and Au stands for gold. The vertical columns in the periodic table are known as groups, and elements in groups tend to have very similar properties. The table is also divided into rows, known as periods. "
"the helium atom has 2 protons, 2 electrons and 2 neutrons. what is its atomic number?",(A) 2 (B) 4 (C) 6 (D) 8,A,"There is another number in the box above for helium. That number is the mass number, which is the mass of the atom in a unit called the atomic mass unit (amu). One atomic mass unit is the mass of a proton, or about 1.67 1027 kilograms, which is an extremely small mass. A neutron has just a tiny bit more mass than a proton, so its mass is often assumed to be one atomic mass unit as well. Because electrons have virtually no mass, just about all the mass of an atom is in its protons and neutrons. Therefore, the total number of protons and neutrons in an atom determines its mass in atomic mass units. Consider helium again. Most helium atoms have two neutrons in addition to two protons. Therefore the mass of most helium atoms is 4 atomic mass units (2 amu for the protons + 2 amu for the neutrons). However, some helium atoms have more or less than two neutrons. Atoms with the same number of protons but different numbers of neutrons are called isotopes. Because the number of neutrons can vary for a given element, the mass numbers of different atoms of an element may also vary. For example, some helium atoms have three neutrons instead of two. Therefore, they have a different mass number than the one given in the box above. Q: What is the mass number of a helium atom that has three neutrons? A: The mass number is the number of protons plus the number of neutrons. For helium atoms with three neutrons, the mass number is 2 (protons) + 3 (neutrons) = 5. Q: How would you represent this isotope of helium to show its atomic number and mass number? A: You would represent it by the elements symbol and both numbers, with the mass number on top and the atomic number on the bottom: 5 2 He "
lithium (li) has similar properties to what other element?,(A) He (B) Na (C) C (D) O,B,"Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very eager to gain an electron. Click image to the left or use the URL below. URL: "
which of the following is an element?,(A) O (B) O2 (C) H2O (D) CO2,A,An element is a pure substance. It cannot be separated into any other substances. There are more than 90 different elements that occur in nature. Some are much more common than others. Hydrogen is the most common element in the universe. Oxygen is the most common element in Earths crust. Figure 3.7 shows other examples of elements. Still others are described in the video below. MEDIA Click image to the left or use the URL below. URL: 
chromosomal mutations usually happen when the organism is forming.,(A) true (B) false,B,"Mutations may also occur in chromosomes ( Figure 1.1). These mutations are going to be fairly large mutations, possible affecting many genes. Possible types of mutations in chromosomes include: 1. Deletion: When a segment of DNA is lost, so there is a missing segment in the chromosome. These usually result in many genes missing from the chromosome. 2. Duplication: When a segment of DNA is repeated, creating a longer chromosome. These usually result in multiple copies of genes in the chromosome. 3. Inversion: When a segment of DNA is flipped and then reattached to the same chromosome. 4. Insertion: When a segment of DNA from one chromosome is added to another, unrelated chromosome. 5. Translocation: When two segments from different chromosomes change positions. "
down syndrome people have 47 chromosomes.,(A) true (B) false,A,"One common example of an extra-chromosome disorder is Down syndrome ( Figure 1.1). Children with Down syndrome are mentally disabled and also have physical deformities. Down syndrome occurs when a baby receives an extra chromosome 21 from one of his or her parents. Usually, a child will receive one chromosome 21 from the mother and one chromosome 21 from the father. In an individual with Down syndrome, however, there are three Chromosomes of a person with Down Syndrome. Notice the extra chromosome 21. copies of chromosome 21 ( Figure 1.2). Therefore, Down syndrome is also known as Trisomy 21. These people have 47 total chromosomes. Another example of a chromosomal disorder is Klinefelter syndrome, in which a male inherits an extra X chromosome. These individuals have an XXY genotype. They have underdeveloped sex organs and elongated limbs. They also have difficulty learning new things. "
down syndromw is also known as,(A) Trisomy 2 (B) Trisomy 20 (C) Trisomy 21 (D) Trisomy 22,A,"One common example of an extra-chromosome disorder is Down syndrome ( Figure 1.1). Children with Down syndrome are mentally disabled and also have physical deformities. Down syndrome occurs when a baby receives an extra chromosome 21 from one of his or her parents. Usually, a child will receive one chromosome 21 from the mother and one chromosome 21 from the father. In an individual with Down syndrome, however, there are three Chromosomes of a person with Down Syndrome. Notice the extra chromosome 21. copies of chromosome 21 ( Figure 1.2). Therefore, Down syndrome is also known as Trisomy 21. These people have 47 total chromosomes. Another example of a chromosomal disorder is Klinefelter syndrome, in which a male inherits an extra X chromosome. These individuals have an XXY genotype. They have underdeveloped sex organs and elongated limbs. They also have difficulty learning new things. "
what is the genotype of males with klinefelter syndrome?,(A) YYY (B) XYY (C) XXY (D) XXX,C,"In people, the sex chromosomes are called X and Y chromosomes. Individuals with two X chromosomes are normally females. Individuals with one X and one Y chromosome are normally males. As you can see in Figure sons. "
cri du chat individuals have an extra part of chromosome,(A) 1 (B) 5 (C) 15 (D) 25,B,"Chromosomal disorders also occur when part of a chromosome becomes damaged. For example, if a tiny portion of chromosome 5 is missing, the individual will have cri du chat (cats cry) syndrome. These individuals have misshapen facial features, and the infants cry resembles a cats cry. "
"a normal genotype can be described as 46, xx (or 46, xy). turner syndrome can be described as 45, x. what would this refer to?",(A) one less autosome (B) one less sex chromsome (C) one more sex chromosome (D) only 1 chromosome,B,"In people, the sex chromosomes are called X and Y chromosomes. Individuals with two X chromosomes are normally females. Individuals with one X and one Y chromosome are normally males. As you can see in Figure sons. "
what are the sex chromosomes in a female with klinefelter syndrome?,(A) XXX (B) XXY (C) XYY (D) Females do not get Klinefelter syndrome (E) so the sex chromosomes are XX,D,"In people, the sex chromosomes are called X and Y chromosomes. Individuals with two X chromosomes are normally females. Individuals with one X and one Y chromosome are normally males. As you can see in Figure sons. "
the lymphatic system is a closed circulatory system.,(A) true (B) false,B,"You may think that your blood vessels have thick walls without any leaks, but thats not true. Blood vessels can leak just like any other pipe. The lymphatic system makes sure leaked blood returns back to the bloodstream. When a small amount of fluid leaks out from the blood vessels, it collects in the spaces between cells and tissues. Some of the fluid returns to the cardiovascular system, and the rest is collected by the lymph vessels of the lymphatic system ( Figure 1.2). The fluid that collects in the lymph vessels is called lymph. The lymphatic system then returns the lymph to the cardiovascular system. Unlike the cardiovascular system, the lymphatic system is not closed (meaning it is an open circulatory system that releases and collects fluid) and has no central pump (or heart). Lymph moves slowly in lymph vessels. It is moved along in the lymph vessels by the squeezing action of smooth muscles and skeletal muscles. Lymph capillaries collect fluid that leaks out from blood capillaries. The lymphatic vessels return the fluid to the cardiovas- cular system. "
the heart pumps lymph throughout the lymphatic system.,(A) true (B) false,B,"Lymph vessels make up a circulatory system that is similar to the blood vessels of the cardiovascular system. However, lymph vessels circulate lymph instead of blood, and the heart does not pump lymph through the vessels. Lymph that collects in tissues slowly passes into tiny lymph vessels. Lymph then travels from smaller to larger lymph vessels. Muscles around the lymph vessels contract and squeeze the lymph through the vessels. The lymph vessels also contract to help move the lymph along. Eventually, lymph reaches the main lymph vessels, which are located in the chest. From these vessels, lymph drains into two large veins of the cardiovascular system. This is how lymph returns to the blood. Before lymph reaches the bloodstream, it passes through small oval structures called lymph nodes, which are located along the lymph vessels. Figure 21.14 shows where some of the bodys many lymph nodes are concentrated. Lymph nodes act like filters and remove pathogens from lymph. "
the lymphatic system works with the __________ system to protect your body.,(A) cardiovascular (B) endocrine (C) immune (D) all of the above,C,"The lymphatic system is a network of vessels and tissues that carry a clear fluid called lymph. The lymphatic system ( Figure 1.1) spreads all around the body and filters and cleans the lymph of any debris, abnormal cells, or pathogens. Lymph vessels are tube-shaped, just like blood vessels, with about 500-600 lymph nodes (in an adult) attached. The lymphatic system works with the cardiovascular system to return body fluids to the blood. The lymphatic system and the cardiovascular system are often called the bodys two ""circulatory systems."" Organs of the lymphatic system include the tonsils, thymus gland and spleen. The thymus gland produces T cells or T-lymphocytes (see below) and the spleen and tonsils help in fighting infections. The spleens main function is to filter the blood, removing unwanted red blood cells. The spleen also detects viruses and bacteria and triggers the release of pathogen fighting cells. The lymphatic system helps return fluid that leaks from the blood vessels back to the cardiovascular system. "
what part of the lymphatic system acts as a trap for foreign particles?,(A) the lymph (B) the lymph nodes (C) the thymus gland (D) the blood,A,"The lymphatic system also plays an important role in the immune system. For example, the lymphatic system makes white blood cells that protect the body from diseases. Cells of the lymphatic system produce two types of white blood cells, T cells and B cells, that are involved in fighting specific pathogens. Lymph nodes, which are scattered throughout the lymphatic system, act as filters or traps for foreign particles and are important in the proper functioning of the immune system. The role of the lymphatic system in the immune response is discussed in additional concepts. "
the lymphatic system helps return fluid to the,(A) immune system (B) endocrine system (C) circulatory system (D) respiratory system,C,"The lymphatic system is a network of vessels and tissues that carry a clear fluid called lymph. The lymphatic system ( Figure 1.1) spreads all around the body and filters and cleans the lymph of any debris, abnormal cells, or pathogens. Lymph vessels are tube-shaped, just like blood vessels, with about 500-600 lymph nodes (in an adult) attached. The lymphatic system works with the cardiovascular system to return body fluids to the blood. The lymphatic system and the cardiovascular system are often called the bodys two ""circulatory systems."" Organs of the lymphatic system include the tonsils, thymus gland and spleen. The thymus gland produces T cells or T-lymphocytes (see below) and the spleen and tonsils help in fighting infections. The spleens main function is to filter the blood, removing unwanted red blood cells. The spleen also detects viruses and bacteria and triggers the release of pathogen fighting cells. The lymphatic system helps return fluid that leaks from the blood vessels back to the cardiovascular system. "
about how many lymph nodes are in a typical adult?,(A) 50 (B) 100 (C) 500 (D) 1000,A,"The lymphatic system is a network of vessels and tissues that carry a clear fluid called lymph. The lymphatic system ( Figure 1.1) spreads all around the body and filters and cleans the lymph of any debris, abnormal cells, or pathogens. Lymph vessels are tube-shaped, just like blood vessels, with about 500-600 lymph nodes (in an adult) attached. The lymphatic system works with the cardiovascular system to return body fluids to the blood. The lymphatic system and the cardiovascular system are often called the bodys two ""circulatory systems."" Organs of the lymphatic system include the tonsils, thymus gland and spleen. The thymus gland produces T cells or T-lymphocytes (see below) and the spleen and tonsils help in fighting infections. The spleens main function is to filter the blood, removing unwanted red blood cells. The spleen also detects viruses and bacteria and triggers the release of pathogen fighting cells. The lymphatic system helps return fluid that leaks from the blood vessels back to the cardiovascular system. "
what is the role of the spleen?,(A) to make T cells (B) to filter the blood (C) to return blood to the circulatory system (D) to fight pathogens,B,"Immune system organs include bone marrow, the thymus gland, the spleen, and the tonsils. Each organ has a different job in the immune system. Bone marrow is found inside many bones. Its role in the immune system is to produce white blood cells called lymphocytes. The thymus gland is in the chest behind the breast bone. It stores some types of lymphocytes while they mature. The spleen is in the abdomen below the lungs. Its job is to filter pathogens out of the blood. The two tonsils are located on either side of the throat. They trap pathogens that enter the body through the mouth or nose. "
the products of cellular respiration are the reactants of photosynthesis.,(A) true (B) false,A,"Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Together, these two processes provide energy to almost all of Earths organisms. The two processes are closely related, as you can see in the Figure 1.1. In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use. A: In photosynthesis, carbon dioxide (CO2 ) and water (H2 O) are the reactants. They combine using energy from light to produce oxygen (O2 ) and glucose (C6 H12 O6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy. "
cellular respiration and photosynthesis are important processes in the recycling of carbon.,(A) true (B) false,A,"Cellular respiration and photosynthesis are like two sides of the same coin. This is clear from the diagram in Figure needed for photosynthesis. Together, the two processes store and release energy in virtually all living things. "
what is needed by our cells to allow aerobic cellular respiration to proceed?,(A) oxygen (B) water (C) ATP (D) carbon dioxide,A,"The pyruvate molecules from glycolysis next enter the matrix of a mitochondrion. Thats where the second stage of cellular respiration takes place. This stage is called the Krebs cycle. During this stage, two more molecules of ATP are produced. Other energy-storing molecules are also produced (to be used to make more ATP in stage 3). The Krebs cycle requires oxygen. Anything that needs oxygen is described as aerobic. The oxygen combines with the carbon from the pyruvate molecules. This forms carbon dioxide, a waste product. "
which statement is not true concerning photosynthesis?,(A) Photosynthesis occurs in the chloroplast (B) Light energy from the sun changes to chemical energy in glucose (C) Chemical energy in glucose is converted to chemical energy in ATP (D) Light energy is used to make glucose and oxygen,C,"The second stage of photosynthesis is the production of glucose from carbon dioxide. This process occurs in a continuous cycle, named after its discover, Melvin Calvin. The Calvin cycle uses CO2 and the energy temporarily stored in ATP and NADPH to make the sugar glucose. "
which statement is not true concerning cellular respiration?,(A) Cellular respiration occurs in the mitochondria (B) Carbon dioxide is formed (C) and the it can be used in photosynthesis (D) c Chemical energy in glucose is converted to chemical energy in ATP (E) d Light energy is used to make ATP,D,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
what is an outcome from a lack of oxygen?,(A) Much less ATP is produced (B) Much less glucose is produced (C) Much less water is used (D) all of the above,A,"Like any other muscle, your heart needs oxygen. Hearts have arteries that provide oxygen through the blood. They are known as coronary arteries. Coronary heart disease is the end result of the buildup of plaque within the walls of the coronary arteries. Coronary heart disease often does not have any symptoms. A symptom of coronary heart disease is chest pain. Occasional chest pain can happen during times of stress or physical activity. The pain of angina means the heart muscle fibers need more oxygen than they are getting. Most people with coronary heart disease often have no symptoms for many years until they have a heart attack. A heart attack happens when the blood cannot reach the heart because a blood vessel is blocked. If cardiac muscle is starved of oxygen for more than roughly five minutes, it will die. Cardiac muscle cells cannot be replaced, so once they die, they are dead forever. Coronary heart disease is the leading cause of death of adults in the United States. The image below shows the way in which a blocked coronary artery can cause a heart attack and cause part of the heart muscle to die ( Figure 1.2). Maybe one day stem cells will be used to replace dead cardiac muscle cells. "
"in type 1 diabetes, the pancreas produces defective insulin.",(A) true (B) false,B,"Type 1 diabetes is caused by the immune system attacking and destroying normal cells of the pancreas. As a result, the cells can no longer produce insulin. Why the immune system acts this way is not known for certain. Its possible that a virus may trigger the attack. This type of diabetes usually develops in childhood or adolescence. At present, there is no known way to prevent the development of type 1 diabetes. However, it is a treatable disease. Treatment of type 1 diabetes includes: taking several insulin injections every day or using an insulin pump (see Figure 21.7). monitoring blood glucose levels several times a day. eating a healthy diet that spreads out carbohydrate intake throughout the day. regular physical activity, which helps the body use insulin more efficiently. regular medical checkups. "
"in type 2 diabetes, the pancreas produces insulin, but the insulin is not used correctly.",(A) true (B) false,A,"Type 2 diabetes occurs when body cells are no longer sensitive to insulin. The pancreas may still make insulin, but the cells of the body cannot use it efficiently. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. Type 2 diabetes usually develops in adulthood, but it is becoming more common in teens and children. This is because more young people are overweight, due to a high sugar and fat diet, now than ever before. Some cases of type 2 diabetes can be cured with weight loss. However, most people with the disease need to take medicine to control their blood sugar. Regular exercise and balanced eating also help, and should be a regular part of the treatment for these people. Like people with type 1 diabetes, people with type 2 diabetes must frequently check their blood sugar. "
what causes type 1 diabetes?,(A) damage to the cells of the pancreas (B) damage to the cells of the liver (C) the production of defective insulin (D) too much sugar in the diet,A,"Type 1 diabetes is caused by the immune system attacking and destroying normal cells of the pancreas. As a result, the cells can no longer produce insulin. Why the immune system acts this way is not known for certain. Its possible that a virus may trigger the attack. This type of diabetes usually develops in childhood or adolescence. At present, there is no known way to prevent the development of type 1 diabetes. However, it is a treatable disease. Treatment of type 1 diabetes includes: taking several insulin injections every day or using an insulin pump (see Figure 21.7). monitoring blood glucose levels several times a day. eating a healthy diet that spreads out carbohydrate intake throughout the day. regular physical activity, which helps the body use insulin more efficiently. regular medical checkups. "
what causes type 2 diabetes?,(A) damage to the cells of the kidney (B) damage to the cells of the pancreas (C) cells that cannot use insulin (D) the production of defective insulin,C,"Type 2 diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body cant use it. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before. You can greatly reduce your risk of developing type 2 diabetes by maintaining a healthy body weight. Some cases of type 2 diabetes can be cured with weight loss. However, most people with the disease need to take medicine to control their blood glucose. Regular exercise and balanced eating also help. Like people with type 1 diabetes, people with type 2 diabetes must frequently check their blood glucose. "
which of the following is a symptom of diabetes?,(A) loss of appetite (B) feeling very thirsty (C) hearing loss (D) all of the above,B,"Common symptoms of diabetes include the following: frequent urination feeling very thirsty feeling very hungry, even though you are eating extreme fatigue blurry vision cuts or bruises that are slow to heal weight loss, even though you are eating more (type 1) tingling, pain, or numbness in the hands or feet (type 2) "
which of the following is a complication of diabetes?,(A) kidney disease (B) vision complications (C) high blood pressure (D) all of the above,D,Complications of diabetes can include the following: eye complications foot complications skin complications high blood pressure hearing issues nerve damage kidney disease artery disease stroke stress 
why is type 2 diabetes becoming more common in children?,(A) Because the gene for type 2 diabetes is more common in the population (B) Because of a high sugar and fat diet (C) Because it is inherited from their parents (D) Because it is easy to get the disease now,B,"Type 2 diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body cant use it. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before. You can greatly reduce your risk of developing type 2 diabetes by maintaining a healthy body weight. Some cases of type 2 diabetes can be cured with weight loss. However, most people with the disease need to take medicine to control their blood glucose. Regular exercise and balanced eating also help. Like people with type 1 diabetes, people with type 2 diabetes must frequently check their blood glucose. "
the mouth is considered an organ of the digestive system.,(A) true (B) false,A,"The mouth is the first digestive organ that food enters. The sight, smell, or taste of food stimulates the release of saliva and digestive enzymes by salivary glands inside the mouth. Saliva wets the food, which makes it easier to break up and swallow. The enzyme amylase in saliva begins the chemical digestion of starches to sugars. Your teeth help to mechanically digest food. Look at the different types of human teeth in Figure 17.13. Sharp teeth in the front of the mouth cut or tear food when you bite into it. Broad teeth in the back of the mouth grind food when you chew. Your tongue helps mix the food with saliva and enzymes and also helps you swallow. When you swallow, a lump of chewed food passes from the mouth into a tube in your throat called the pharynx. From the pharynx, the food passes into the esophagus. "
the movement of food through your digestive system is an involuntary process.,(A) true (B) false,A,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
which protein is found in the stomach?,(A) saliva (B) pepsin (C) amylase (D) cecum,B,"The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls that contract and relax to squeeze and mix food. This helps break the food into smaller pieces. It also helps mix the food with enzymes and other secretions in the stomach. For example, the stomach secretes the enzyme pepsin, which helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the lining of the stomach. However, most substances must undergo further digestion in the small intestine before they can be absorbed. The stomach stores the partly digested food until the small intestine is empty. Then a sphincter between the stomach and small intestine relaxes, allowing food to enter the small intestine. "
what is peristalsis?,(A) The absorption of nutrients in the small intestine (B) The release of waste at the end of the digestive process (C) Muscle contractions that help food move through the digestive system (D) The release of digestive enzymes from the digestive organs,C,"The esophagus is a long, narrow tube that carries food from the pharynx to the stomach. It has no other purpose. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle, called a sphincter, controls the opening to the stomach. The sphincter relaxes to let food pass into the stomach. Then the sphincter contracts to prevent food from passing back into the esophagus. "
what is the first step in the digestive process?,(A) the mechanical breakdown of food (B) the release of saliva and digestive enzymes in your mouth (C) the chemical digestion of food (D) the swallowing of food down the esophagus,B,"As food is pushed through the GI tract by peristalsis, it undergoes digestion. Digestion is the process of breaking down food into nutrients. There are two types of digestion: mechanical digestion and chemical digestion. Mechanical digestion occurs when large chunks of food are broken down into smaller pieces. This is a physical process that happens mainly in the mouth and stomach. Chemical digestion occurs when large food molecules are broken down into smaller nutrient molecules. This is a chemical process that begins in the mouth and stomach but occurs mainly in the small intestine. "
which statement is associated with the small intestine of an adult?,(A) organ where most absorption occurs (B) covered with millions of villi (C) over 20 feet long (D) all of the above,D,"The large intestine is a wide tube that connects the small intestine with the anus. In adults, the large intestine is about 1.5 meters (5 feet) long. It is larger in width but shorter in length than the small intestine. "
which depicts the correct order of food traveling through the digestive system?,(A) mouth- esophagus – stomach – large intestine – small intestine - anus (B) mouth- esophagus – stomach – pancreas – intestine - anus (C) mouth – esophagus – stomach - small intestine - large intestine - anus (D) mouth- esophagus – liver – stomach – intestine - anus,C,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
headaches are an illness of the nervous system.,(A) true (B) false,A,"Like other parts of the body, the nervous system may develop tumors. A tumor is a mass of cells that grows out of control. A tumor in the brain may press on normal brain tissues. This can cause headaches, difficulty speaking, or other problems, depending on where the tumor is located. Pressure from a tumor can even cause permanent brain damage. In many cases, brain tumors can be removed with surgery. In other cases, tumors cant be removed without damaging the brain even more. In those cases, other types of treatments may be needed. Cerebral palsy is a disease caused by injury to the developing brain. The injury occurs before, during, or shortly after birth. Cerebral palsy is more common in babies that have a low weight at birth. But the cause of the brain injury is not often known. The disease usually affects the parts of the brain that control body movements. Symptoms range from weak muscles in mild cases to trouble walking and talking in more severe cases. There is no known cure for cerebral palsy. Epilepsy is a disease that causes seizures. A seizure is a period of lost consciousness that may include violent muscle contractions. It is caused by abnormal electrical activity in the brain. The cause of epilepsy may be an infection, a brain injury, or a tumor. The seizures of epilepsy can often be controlled with medicine. There is no known cure for the disease, but children with epilepsy may outgrow it by adulthood. A headache is a very common nervous system problem. Headaches may be a symptom of serious diseases, but they are more commonly due to muscle tension. A tension headache occurs when muscles in the shoulders, neck, and head become too tense. This often happens when people are stressed out. Just trying to relax may help relieve this type of headache. Mild pain relievers such as ibuprofen may also help. Sometimes relaxation is the best medicine for a tension headache and to help muscles get rid of pain. A migraine is a more severe type of headache. It occurs when blood vessels in the head dilate, or expand. This may be triggered by certain foods, bright lights, weather changes, or other factors. People with migraines may also have nausea or other symptoms. Fortunately, migraines can often be relieved with prescription drugs. There are many other nervous system diseases. They include multiple sclerosis, Huntingtons disease, Parkinsons disease, and Alzheimers disease. However, these diseases rarely, if ever, occur in young people. Their causes and symptoms are listed below ( Table 1.1). The diseases have no known cure, but medicines may help control their symptoms. Disease Multiple sclerosis Cause The immune system attacks and damages the central nervous sys- tem so neurons cannot function nor- mally. Symptoms Muscle weakness, difficulty mov- ing, problems with coordination, difficulty keeping the body bal- anced Parkinsons disease Alzheimers disease "
cns diseases can be caused by bacteria and viruses getting into the brain or spinal cord.,(A) true (B) false,A,"Bacteria and viruses can infect the brain or spinal cord. An infection of the brain is called encephalitis. An infection of the membranes that cover the brain and spinal cord is called meningitis. A vaccine is available to prevent meningitis caused by viruses (see Figure 20.8). Encephalitis and meningitis arent very common, but they can be extremely serious. They may cause swelling of the brain, which can be fatal. Thats why its important to know the symptoms of these diseases. Both encephalitis and meningitis typically cause a severe headache and a fever. Meningitis also causes a stiff neck. Both require emergency medical treatment. "
"which nervous system disease is characterized by memory loss, confusion, and the gradual loss of control over mental and physical abilities?",(A) Multiple Sclerosis (B) Huntington’s Disease (C) Parkinson’s Disease (D) Alzheimer’s Disease,D,"Alzheimers disease is another disease that occurs mainly in older adults. In Alzheimers disease, a person gradually loses most normal mental functions. The patient typically suffers from increasing memory loss, confusion, and mood swings. The cause of Alzheimers isnt known for certain, but it appears to be associated with certain abnormal changes in the brain. There is no known cure for this devastating disease, but medicines may be able to slow its progression. "
which nervous system disease results from the immune system attacking and damaging the central nervous system?,(A) Multiple Sclerosis (B) Huntington’s Disease (C) Parkinson’s Disease (D) Alzheimer’s Disease,A,Nervous system problems include diseases and injuries. Most nervous system diseases cant be prevented. But you can take steps to decrease your risk of nervous system injuries. 
"which nervous system disease is associated with uncontrolled shaking, slowed movements, and problems with speaking?",(A) Multiple Sclerosis (B) Huntington’s Disease (C) Parkinson’s Disease (D) Alzheimer’s Disease,C,"The nervous system controls sensing, feeling, and thinking. It also controls movement and just about every other body function. Thats why problems with the nervous system can affect the entire body. Diseases of the nervous system include brain and spinal cord infections. Other problems of the nervous system range from very serious diseases, such as tumors, to less serious problems, such as tension headaches. Some of these diseases are present at birth. Others begin during childhood or adulthood. "
which nervous system disease is caused by an abnormal protein that causes the death of neurons?,(A) Multiple Sclerosis (B) Huntington’s Disease (C) Parkinson’s Disease (D) Alzheimer’s Disease,B,"Like other parts of the body, the nervous system may develop tumors. A tumor is a mass of cells that grows out of control. A tumor in the brain may press on normal brain tissues. This can cause headaches, difficulty speaking, or other problems, depending on where the tumor is located. Pressure from a tumor can even cause permanent brain damage. In many cases, brain tumors can be removed with surgery. In other cases, tumors cant be removed without damaging the brain even more. In those cases, other types of treatments may be needed. Cerebral palsy is a disease caused by injury to the developing brain. The injury occurs before, during, or shortly after birth. Cerebral palsy is more common in babies that have a low weight at birth. But the cause of the brain injury is not often known. The disease usually affects the parts of the brain that control body movements. Symptoms range from weak muscles in mild cases to trouble walking and talking in more severe cases. There is no known cure for cerebral palsy. Epilepsy is a disease that causes seizures. A seizure is a period of lost consciousness that may include violent muscle contractions. It is caused by abnormal electrical activity in the brain. The cause of epilepsy may be an infection, a brain injury, or a tumor. The seizures of epilepsy can often be controlled with medicine. There is no known cure for the disease, but children with epilepsy may outgrow it by adulthood. A headache is a very common nervous system problem. Headaches may be a symptom of serious diseases, but they are more commonly due to muscle tension. A tension headache occurs when muscles in the shoulders, neck, and head become too tense. This often happens when people are stressed out. Just trying to relax may help relieve this type of headache. Mild pain relievers such as ibuprofen may also help. Sometimes relaxation is the best medicine for a tension headache and to help muscles get rid of pain. A migraine is a more severe type of headache. It occurs when blood vessels in the head dilate, or expand. This may be triggered by certain foods, bright lights, weather changes, or other factors. People with migraines may also have nausea or other symptoms. Fortunately, migraines can often be relieved with prescription drugs. There are many other nervous system diseases. They include multiple sclerosis, Huntingtons disease, Parkinsons disease, and Alzheimers disease. However, these diseases rarely, if ever, occur in young people. Their causes and symptoms are listed below ( Table 1.1). The diseases have no known cure, but medicines may help control their symptoms. Disease Multiple sclerosis Cause The immune system attacks and damages the central nervous sys- tem so neurons cannot function nor- mally. Symptoms Muscle weakness, difficulty mov- ing, problems with coordination, difficulty keeping the body bal- anced Parkinsons disease Alzheimers disease "
which nervous system disease causes seizures?,(A) cerebral palsy (B) epilepsy (C) migraine (D) meningitis,B,"Like other parts of the body, the nervous system may develop tumors. A tumor is a mass of cells that grows out of control. A tumor in the brain may press on normal brain tissues. This can cause headaches, difficulty speaking, or other problems, depending on where the tumor is located. Pressure from a tumor can even cause permanent brain damage. In many cases, brain tumors can be removed with surgery. In other cases, tumors cant be removed without damaging the brain even more. In those cases, other types of treatments may be needed. Cerebral palsy is a disease caused by injury to the developing brain. The injury occurs before, during, or shortly after birth. Cerebral palsy is more common in babies that have a low weight at birth. But the cause of the brain injury is not often known. The disease usually affects the parts of the brain that control body movements. Symptoms range from weak muscles in mild cases to trouble walking and talking in more severe cases. There is no known cure for cerebral palsy. Epilepsy is a disease that causes seizures. A seizure is a period of lost consciousness that may include violent muscle contractions. It is caused by abnormal electrical activity in the brain. The cause of epilepsy may be an infection, a brain injury, or a tumor. The seizures of epilepsy can often be controlled with medicine. There is no known cure for the disease, but children with epilepsy may outgrow it by adulthood. A headache is a very common nervous system problem. Headaches may be a symptom of serious diseases, but they are more commonly due to muscle tension. A tension headache occurs when muscles in the shoulders, neck, and head become too tense. This often happens when people are stressed out. Just trying to relax may help relieve this type of headache. Mild pain relievers such as ibuprofen may also help. Sometimes relaxation is the best medicine for a tension headache and to help muscles get rid of pain. A migraine is a more severe type of headache. It occurs when blood vessels in the head dilate, or expand. This may be triggered by certain foods, bright lights, weather changes, or other factors. People with migraines may also have nausea or other symptoms. Fortunately, migraines can often be relieved with prescription drugs. There are many other nervous system diseases. They include multiple sclerosis, Huntingtons disease, Parkinsons disease, and Alzheimers disease. However, these diseases rarely, if ever, occur in young people. Their causes and symptoms are listed below ( Table 1.1). The diseases have no known cure, but medicines may help control their symptoms. Disease Multiple sclerosis Cause The immune system attacks and damages the central nervous sys- tem so neurons cannot function nor- mally. Symptoms Muscle weakness, difficulty mov- ing, problems with coordination, difficulty keeping the body bal- anced Parkinsons disease Alzheimers disease "
dna is made of long chains of nucleic acids.,(A) true (B) false,B,"Nucleic acids are long chains of nucleotides. Nucleotides are made of a sugar, a nitrogen-containing base, and a phosphate group. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main nucleic acids. DNA is a double-stranded nucleic acid. DNA is the molecule that stores our genetic information ( Figure 1.6). The single- stranded RNA is involved in making proteins. ATP (adenosine triphosphate), known as the ""energy currency"" of the cell, is also a nucleic acid. "
deoxyribose is the base in dna.,(A) true (B) false,B,"As you can see in Figure 5.1, each nucleotide includes a sugar, a phosphate, and a nitrogen base. The sugar in DNA is called deoxyribose. There are four different nitrogen bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). Chemical bonds between the bases hold the two strands of DNA together. Adenine always bonds with thymine, and cytosine always bonds with guanine. These pairs of bases are called complementary base pairs. "
which of the following lists the components of a nucleotide?,(A) a phosphate group (B) a deoxyribose (C) a nitrogen-containing base (D) b a phosphate group (E) a ribose (F) a nitrogen-containing base (G) c a nitrogen group (H) a deoxyribose (I) a phosphate-containing base (J) d a nitrogen group (K) a ribose (L) a phosphate-containing base,A,"Nucleotides are composed of three main parts: 1. a phosphate group. 2. a 5-carbon sugar (deoxyribose in DNA). 3. a nitrogen-containing base. The only difference between each nucleotide is the identity of the base. There are only four possible bases that make up each DNA nucleotide: adenine (A), guanine (G), thymine (T), and cytosine (C). "
"complete the following sentence. the dna double helix has the __________ and __________ groups on the outside, and the __________ connecting the two strands on the inside of the helix.",(A) bases (B) sugar (C) phosphate (D) b phosphate (E) base (F) sugar (G) c sugar (H) phosphate (I) bases (J) d none of the above,C,"RNA consists of just one chain of nucleotides. DNA consists of two chains. Nitrogen bases on the two chains of DNA form hydrogen bonds with each other. Hydrogen bonds are relatively weak bonds that form between a positively charged hydrogen atom in one molecule and a negatively charged atom in another molecule. Hydrogen bonds form only between adenine and thymine, and between guanine and cytosine. These bonds hold the two chains together and give DNA is characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in the Figure 1.2. Sugars and phosphate groups form the backbone of each chain of DNA. The bonded bases are called base pairs. Determining the structure of DNA was a huge scientific breakthrough. Q: Compare the structure of DNA to a spiral staircase. What part of the molecule do the stair steps represent? A: The steps represent the base pairs. "
"if one dna strand reads atcccgag, the other strand will be made up of the complementary bases __________.",(A) TAGGGCTG (B) TACCCGTC (C) TAGGGCTC (D) ATGGGCTC,C,"The bases in DNA do not pair randomly. When Erwin Chargaff looked closely at the bases in DNA, he noticed that the percentage of adenine (A) in the DNA always equaled the percentage of thymine (T), and the percentage of guanine (G) always equaled the percentage of cytosine (C). Watson and Cricks model explained this result by suggesting that A always pairs with T, and G always pairs with C in the DNA helix. Therefore A and T, and G and C, are ""complementary bases,"" or bases that always pair together, known as a base-pair. The base-pairing rules state that A will always bind to T, and G will always bind to C (Figure 1.2). For example, if one DNA strand reads ATGCCAGT, the other strand will be made up of the complementary bases: TACGGTCA. Hydrogen bonds hold the complementary bases together, with two bonds forming between an A and a T, and three bonds between a G and a C. The chemical structure of DNA includes a chain of nucleotides consisting of a 5- carbon sugar, a phosphate group, and a nitrogen base. Notice how the sugar and phosphate group form the backbone of DNA (strands highlighted in pink), with the hydrogen bonds between the bases joining the two strands. "
complementary bases are connected by hydrogen bonds. how many hydrogen bonds connect a cytosine to a guanine?,(A) 1 (B) 2 (C) 3 (D) 4,C,"The bases in DNA do not pair randomly. When Erwin Chargaff looked closely at the bases in DNA, he noticed that the percentage of adenine (A) in the DNA always equaled the percentage of thymine (T), and the percentage of guanine (G) always equaled the percentage of cytosine (C). Watson and Cricks model explained this result by suggesting that A always pairs with T, and G always pairs with C in the DNA helix. Therefore A and T, and G and C, are ""complementary bases,"" or bases that always pair together, known as a base-pair. The base-pairing rules state that A will always bind to T, and G will always bind to C (Figure 1.2). For example, if one DNA strand reads ATGCCAGT, the other strand will be made up of the complementary bases: TACGGTCA. Hydrogen bonds hold the complementary bases together, with two bonds forming between an A and a T, and three bonds between a G and a C. The chemical structure of DNA includes a chain of nucleotides consisting of a 5- carbon sugar, a phosphate group, and a nitrogen base. Notice how the sugar and phosphate group form the backbone of DNA (strands highlighted in pink), with the hydrogen bonds between the bases joining the two strands. "
"who determined the percentage of adenine (a) in the dna always equaled the percentage of thymine (t), and the percentage of guanine (g) always equaled the percentage of cytosine (c).",(A) James Watson (B) Rosalind Franklin and Maurice Wilkins (C) Erwin Chargaff (D) Gregor Mendel,C,"The bases in DNA do not pair randomly. When Erwin Chargaff looked closely at the bases in DNA, he noticed that the percentage of adenine (A) in the DNA always equaled the percentage of thymine (T), and the percentage of guanine (G) always equaled the percentage of cytosine (C). Watson and Cricks model explained this result by suggesting that A always pairs with T, and G always pairs with C in the DNA helix. Therefore A and T, and G and C, are ""complementary bases,"" or bases that always pair together, known as a base-pair. The base-pairing rules state that A will always bind to T, and G will always bind to C (Figure 1.2). For example, if one DNA strand reads ATGCCAGT, the other strand will be made up of the complementary bases: TACGGTCA. Hydrogen bonds hold the complementary bases together, with two bonds forming between an A and a T, and three bonds between a G and a C. The chemical structure of DNA includes a chain of nucleotides consisting of a 5- carbon sugar, a phosphate group, and a nitrogen base. Notice how the sugar and phosphate group form the backbone of DNA (strands highlighted in pink), with the hydrogen bonds between the bases joining the two strands. "
echinoderms have an amazing power of regeneration.,(A) true (B) false,A,Echinoderms are important for the ecosystem. They are also a source of food and medicine for humans. 
"echinoderms, such as starfish, have a hard external skeleton.",(A) true (B) false,B,"As mentioned earlier, echinoderms show radial symmetry. Other key echinoderm features include an internal skeleton and spines, as well as a few organs and organ systems. Although echinoderms look like they have a hard exterior, they do not have an external skeleton. Instead, a thin outer skin covers an internal skeleton made of tiny plates and spines. This provides rigid support. Some groups of echinoderms, such as sea urchins ( Figure 1.2), have spines that protect the organism. Sea cucumbers use these spines to help them move. A starfish (left) and a keyhole sand dollar (right), showing the radial symmetry char- acteristic of the echinoderms. Starfish are also known as sea stars. Another echinoderm, a sea urchin (Echi- nus esculentus), showing its spines. Echinoderms have a unique water vascular system. This network of fluid-filled tubes helps them to breathe, eat, and move. Therefore, they can function without gill slits. Echinoderms also have a very simple digestive system, circulatory system, and nervous system. The digestive system often leads directly from the mouth to the anus. The echinoderms have an open circulatory system, meaning that fluid moves freely in the body cavity. But echinoderms have no heart. This may be due to their simple radial symmetry - a heart is not needed to pump the freely moving fluid. The echinoderm nervous system is a nerve net, or interconnected neurons with no central brain. Many echinoderms have amazing powers of regeneration. For example, some sea stars (starfish) are capable of regenerating lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star! Sea cucumbers often release parts of their internal organs if they perceive danger. The released organs and tissues are then quickly regenerated. "
the water vascular system helps echinoderms,(A) breathe (B) eat and sleep (C) b breathe (D) eat and move (E) c breathe (F) eat and digest food (G) d regenerate and reproduce,B,"While almost all echinoderms live on the sea floor, some sea-lilies can swim at great speeds for brief periods of time, and a few sea cucumbers are fully floating. Some echinoderms find other ways of moving. For example, crinoids attach themselves to floating logs, and some sea cucumbers move by attaching to the sides of fish. On the underside side of a sea star, there are hundreds of tiny feet usually arranged into several rows on each ray of the star. These are called tube feet, or podia, and are filled with seawater in most echinoderms. The water vascular system within the body of the animal is also filled with seawater. By expanding and contracting chambers within the water vascular system, the echinoderm can force water into certain tube feet to extend them. The animal has muscles in the tube feet, which are used to retract them. By expanding and retracting the right tube feet in the proper order, the animal can walk. "
what type of feeder is a sea urchin?,(A) filter-feeder (B) grazer (C) deposit feeder (D) active hunter,B,"Feeding strategies vary greatly among the different groups of echinoderms. Theres no one food or technique thats shared by all echinoderms. Different eating-methods include: 1. Passive filter-feeders, which are organisms that absorb suspended nutrients from passing water. Some echino- derms use their long arms to capture food particles floating past in the currents. 2. Grazers, such as sea urchins, are organisms that feed on available plants. Sea urchins are omnivorous, eating both plant and animals. The sea urchin mainly feeds on algae on the coral and rocks, along with decomposing matter such as dead fish, mussels, sponges, and barnacles. 3. Deposit feeders, which are organisms that feed on small pieces of organic matter, usually in the top layer of soil. Sea cucumbers are deposit feeders, living on the ocean floor. They eat the tiny scrap particles that are usually abundant in the environments that they inhabit. 4. Active hunters, which are organisms that actively hunt their prey. Many sea stars are predators, feeding on mollusks like clams by prying apart their shells and actually placing their stomach inside the mollusk shell to digest the meat. "
which phase describes the echinoderm circulatory system?,(A) open circulatory system without a heart (B) open circulatory system with an echinoderm heart (C) closed circulatory system with a two-chamber primitive heart (D) closed circulatory system without a heart,A,"As mentioned earlier, echinoderms show radial symmetry. Other key echinoderm features include an internal skeleton and spines, as well as a few organs and organ systems. Although echinoderms look like they have a hard exterior, they do not have an external skeleton. Instead, a thin outer skin covers an internal skeleton made of tiny plates and spines. This provides rigid support. Some groups of echinoderms, such as sea urchins ( Figure 1.2), have spines that protect the organism. Sea cucumbers use these spines to help them move. A starfish (left) and a keyhole sand dollar (right), showing the radial symmetry char- acteristic of the echinoderms. Starfish are also known as sea stars. Another echinoderm, a sea urchin (Echi- nus esculentus), showing its spines. Echinoderms have a unique water vascular system. This network of fluid-filled tubes helps them to breathe, eat, and move. Therefore, they can function without gill slits. Echinoderms also have a very simple digestive system, circulatory system, and nervous system. The digestive system often leads directly from the mouth to the anus. The echinoderms have an open circulatory system, meaning that fluid moves freely in the body cavity. But echinoderms have no heart. This may be due to their simple radial symmetry - a heart is not needed to pump the freely moving fluid. The echinoderm nervous system is a nerve net, or interconnected neurons with no central brain. Many echinoderms have amazing powers of regeneration. For example, some sea stars (starfish) are capable of regenerating lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star! Sea cucumbers often release parts of their internal organs if they perceive danger. The released organs and tissues are then quickly regenerated. "
what best describes reproduction of most echinoderms?,(A) sexual reproduction with internal fertilization (B) sexual reproduction with external fertilization (C) asexual reproduction with external fertilization (D) asexual reproduction,B,"Some echinoderms can reproduce asexually by fission. However, most echinoderms reproduce sexually. They generally have separate sexes that produce sperm and eggs. Fertilization typically occurs outside the body in the water. Eggs hatch into larvae that have bilateral symmetry and can swim. The larvae undergo metamorphosis to change into the adult form. During metamorphosis, their bilateral symmetry changes to radial symmetry. "
unsafe water supplies can be deadly to humans.,(A) true (B) false,A,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
many parts of the world do not have water treatment plants.,(A) true (B) false,A,"Many people in the world have no choice but to drink from the same polluted river where sewage is dumped. One- fifth of all people in the world, more than 1.1 billion people, do not have access to safe water for drinking, personal cleanliness, and domestic use. Unsafe drinking water carries many pathogens, or disease-causing biological agents such as infectious bacteria and parasites. Toxic chemicals and radiological hazards in water can also cause diseases. "
which of the following is an over-enrichment of chemical nutrients in a body of water?,(A) acidification (B) toxicification (C) nitrification (D) eutrophication,D,"In a marine ecosystem, algae are the producers. Through photosynthesis, they provide glucose for the ecosystem. So, can too much algae be a bad thing? Eutrophication is an over-enrichment of chemical nutrients in a body of water. Usually these nutrients are the nitrogen and phosphorous found in fertilizers. Run-off from lawns or farms can wash fertilizers into rivers or coastal waters. Plants are not the only things that grow more quickly with added fertilizers. Algae like the excess nutrients in fertilizers too. When there are high levels of nutrients in the water, algae populations will grow large very quickly. This leads to overgrowths of algae called algal blooms. However, these algae do not live very long. They die and begin to decompose. This process uses oxygen, removing the oxygen from the water. Without oxygen, fish and shellfish cannot live, and this results in the death of these organisms ( Figure 1.1). Certain types of algal blooms can also create toxins. These toxins can enter shellfish. If humans eat these shellfish, then they can get very sick. These toxins cause neurological problems in humans. "
what diseases are primarily caused by unsafe water supplies?,(A) cancer (B) heart disease (C) digestive system diseases (D) all of the above,C,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
effects of an algal bloom include,(A) removing oxygen from the water (B) toxins entering shellfish (C) the death of fish (D) all of the above,D,"When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. You can see one in Figure 25.5. The algae out-compete other water organisms. They may make the water unfit for human consumption or recreation. "
waterborne diseases are caused,(A) by pathogens in acid rain (B) by eutrophication (C) by pathogens in sewage or animal manure (D) by algal blooms,C,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
about how many deaths each year from extreme diarrhea is due to unsafe water supplies?,(A) under 500 (B) 000 (C) b about 1 million (D) c about 15 million (E) d over 10 million,C,"Unsafe water supplies have drastic effects on human health. Waterborne diseases are diseases due to microscopic pathogens in fresh water. These diseases can be caused by protozoa, viruses, bacteria, and intestinal parasites. In many parts of the world there are no water treatment plants. If sewage or animal manure gets into a river, then people downstream will get sick when they drink the water. According to the World Health Organization (WHO), diarrheal disease is responsible for the deaths of 1.8 million people every year. It was estimated that 88% of the cases of diarrheal disease are caused by unsafe water supplies. "
plants convert glucose into atp through photosynthesis.,(A) true (B) false,B,Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy ! C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose is used for energy by the cells of almost all living things. Plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). How do living things get energy from glucose? The answer is cellular respiration. 
"because of the constant loss of energy, there can be a maximum of 7 trophic levels in a food chain.",(A) true (B) false,B,"Energy is passed up a food chain or web from lower to higher trophic levels. However, only about 10 percent of the energy at one level is passed up the next level. This is represented by the ecological pyramid in Figure 24.6. The other 90 percent of energy at each trophic level is used for metabolic processes or given off to the environment as heat. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. There isnt enough energy left to support additional levels. It also explains why ecosystems need a constant input of energy. You can learn more about ecological pyramids in this video:  . MEDIA Click image to the left or use the URL below. URL: "
how much of the original energy of the producers is available to an organism in the third trophic level?,(A) 10% (B) 1% (C) 01% (D) 10 grams,B,"Energy is passed up a food chain or web from lower to higher trophic levels. However, only about 10 percent of the energy at one level is passed up the next level. This is represented by the ecological pyramid in Figure 24.6. The other 90 percent of energy at each trophic level is used for metabolic processes or given off to the environment as heat. This loss of energy explains why there are rarely more than four trophic levels in a food chain or web. There isnt enough energy left to support additional levels. It also explains why ecosystems need a constant input of energy. You can learn more about ecological pyramids in this video:  . MEDIA Click image to the left or use the URL below. URL: "
which of the following organism would be in the first trophic level?,(A) mouse (B) caterpillar (C) maple tree (D) bee,C,"Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure 24.5. All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are: 1. 2. 3. 4. Trophic level 1 = producers that make their own food Trophic level 2 = primary consumers that eat producers Trophic level 3 = secondary consumers that eat primary consumers Trophic level 4 = tertiary consumers that eat secondary consumers Many consumers feed at more than one trophic level. For example, the bivalves in Figure 24.5 eat both producers and primary consumers. Therefore, they feed at trophic levels 2 and 3. "
what trophic level has autotrophs?,(A) only the first level (B) the first and second levels (C) all levels except the first (D) only the last level,A,"Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure 24.5. All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are: 1. 2. 3. 4. Trophic level 1 = producers that make their own food Trophic level 2 = primary consumers that eat producers Trophic level 3 = secondary consumers that eat primary consumers Trophic level 4 = tertiary consumers that eat secondary consumers Many consumers feed at more than one trophic level. For example, the bivalves in Figure 24.5 eat both producers and primary consumers. Therefore, they feed at trophic levels 2 and 3. "
what trophic level has heterotrophs?,(A) only the first level (B) only the second level (C) all levels except the first (D) only the last level,C,"Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure 24.5. All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are: 1. 2. 3. 4. Trophic level 1 = producers that make their own food Trophic level 2 = primary consumers that eat producers Trophic level 3 = secondary consumers that eat primary consumers Trophic level 4 = tertiary consumers that eat secondary consumers Many consumers feed at more than one trophic level. For example, the bivalves in Figure 24.5 eat both producers and primary consumers. Therefore, they feed at trophic levels 2 and 3. "
in what trophic level would you find a shark?,(A) the first level (B) the second level (C) all levels except the first (D) the last level,D,"Each food chain or food web has organisms at different trophic levels. A trophic level is a feeding position in a food chain or web. The trophic levels are identified in the food web in Figure 24.5. All food chains and webs have at least two or three trophic levels, but they rarely have more than four trophic levels. The trophic levels are: 1. 2. 3. 4. Trophic level 1 = producers that make their own food Trophic level 2 = primary consumers that eat producers Trophic level 3 = secondary consumers that eat primary consumers Trophic level 4 = tertiary consumers that eat secondary consumers Many consumers feed at more than one trophic level. For example, the bivalves in Figure 24.5 eat both producers and primary consumers. Therefore, they feed at trophic levels 2 and 3. "
an enzyme is a protein that speeds up chemical reactions in the body.,(A) true (B) false,A,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
enzymes in saliva break down complex carbohydrates into simple sugars.,(A) true (B) false,A,"The mouth is the first digestive organ that food enters. The sight, smell, or taste of food stimulates the release of saliva and digestive enzymes by salivary glands inside the mouth. Saliva wets the food, which makes it easier to break up and swallow. The enzyme amylase in saliva begins the chemical digestion of starches to sugars. Your teeth help to mechanically digest food. Look at the different types of human teeth in Figure 17.13. Sharp teeth in the front of the mouth cut or tear food when you bite into it. Broad teeth in the back of the mouth grind food when you chew. Your tongue helps mix the food with saliva and enzymes and also helps you swallow. When you swallow, a lump of chewed food passes from the mouth into a tube in your throat called the pharynx. From the pharynx, the food passes into the esophagus. "
what enzyme is produced in the stomach and digests proteins?,(A) amylase (B) pepsin (C) trypsin (D) lipase,B,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
what enzymes are made in the pancreas?,(A) amylase and trypsin (B) pepsin and trypsin (C) trypsin and ribonuclease (D) amylase and lipase,C,"Chemical digestion could not take place without the help of digestive enzymes and other substances secreted into the GI tract. An enzyme is a protein that speeds up a biochemical reaction. Digestive enzymes speed up the reactions of chemical digestion. Table 17.3 lists a few digestive enzymes, the organs that produce them, and their functions in digestion. Enzyme Amylase Pepsin Organ that Produces It mouth stomach Substance It Helps Digest starch protein Enzyme Lipase Ribonuclease Organ that Produces It pancreas pancreas Substance It Helps Digest fat RNA Most digestive enzymes are secreted into the GI tract by organs of the GI tract or from a nearby gland named the pancreas. Figure 17.12 shows where the pancreas is located. The figure also shows the locations of the liver and gall bladder. These organs produce or store other digestive secretions. The liver secretes bile acids. Bile acids help digest fat. Some liver bile is secreted directly into the small intestine. Some liver bile goes to the gall bladder. This sac-like organ stores and concentrates the liver bile before releasing it into the small intestine. "
what hormone signals when you are hungry?,(A) ghrelin (B) gastrin (C) secretin (D) cholecystokinin,A,"If you are a typical teenager, you like to eat. For your body to break down, absorb and spread the nutrients from your food throughout your body, your digestive system and endocrine system need to work together. The endocrine system sends hormones around your body to communicate between cells. Essentially, hormones are chemical messenger molecules. Digestive hormones are made by cells lining the stomach and small intestine. These hormones cross into the blood where they can affect other parts of the digestive system. Some of these hormones are listed below. Gastrin, which signals the secretion of gastric acid. Cholecystokinin, which signals the secretion of pancreatic enzymes. Secretin, which signals secretion of water and bicarbonate from the pancreas. Ghrelin, which signals when you are hungry. Gastric inhibitory polypeptide, which stops or decreases gastric secretion. It also causes the release of insulin in response to high blood glucose levels. "
what enzyme digests lipids?,(A) trypsin (B) pancreatic lipase (C) pepsin (D) gastrin,B,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
what happens to the digestive enzymes after they are used?,(A) they are broken down by proteases (B) they are reabsorbed by the small intestine (C) they return to the bloodstream (D) they are reused,D,"Chemical digestion could not take place without the help of digestive enzymes. An enzyme is a protein that speeds up chemical reactions in the body. Digestive enzymes speed up chemical reactions that break down large food molecules into small molecules. Did you ever use a wrench to tighten a bolt? You could tighten a bolt with your fingers, but it would be difficult and slow. If you use a wrench, you can tighten a bolt much more easily and quickly. Enzymes are like wrenches. They make it much easier and quicker for chemical reactions to take place. Like a wrench, enzymes can also be used over and over again. But you need the appropriate size and shape of the wrench to efficiently tighten the bolt, just like each enzyme is specific for the reaction it helps. Digestive enzymes are released, or secreted, by the organs of the digestive system. These enzymes include proteases that digest proteins, and nucleases that digest nucleic acids. Examples of digestive enzymes are: Amylase, produced in the mouth. It helps break down large starch molecules into smaller sugar molecules. Pepsin, produced in the stomach. Pepsin helps break down proteins into amino acids. Trypsin, produced in the pancreas. Trypsin also breaks down proteins. Pancreatic lipase, produced in the pancreas. It is used to break apart fats. Deoxyribonuclease and ribonuclease, produced in the pancreas. They are enzymes that break bonds in nucleic acids like DNA and RNA. Bile salts are bile acids that help to break down fat. Bile acids are made in the liver. When you eat a meal, bile is secreted into the intestine, where it breaks down the fats ( Figure 1.1). "
you can tell the phenotype of a dog by looking at it.,(A) true (B) false,A,"The expression of an organisms genotype is called its phenotype. The phenotype refers to the organisms traits, such as purple or white flowers. Different genotypes may produce the same phenotype. This will be the case if one allele is dominant to the other. Both BB and Bb genotypes in Table 6.1 have purple flowers. Thats because the B allele is dominant to the b allele, which is recessive. The terms dominant and recessive are the terms Mendel used to describe his ""factors."" Today we use them to describe alleles. In a Bb heterozygote, only the dominant B allele is expressed. The recessive b allele is expressed only in the bb genotype. "
natural selection cannot distinguish between dominant and recessive phenotypes.,(A) true (B) false,B,"Natural selection acts on the phenotype (the traits or characteristics) of an individual. On the other hand, natural selection does not act on the underlying genotype (the genetic makeup) of an individual. For many traits, the homozygous genotype, AA, for example, has the same phenotype as the heterozygous Aa genotype. If both an AA and Aa individual have the same phenotype, the environment cannot distinguish between them. So natural selection cannot select for a homozygous individual over a heterozygous individual. Even if the ""aa"" phenotype is lethal, the recessive a allele, will be maintained in the population through heterozygous Aa individuals. Furthermore, the mating of two heterozygous individuals can produce homozygous recessive (aa) individuals. However, natural selection can and does differentiate between dominant and recessive phenotypes. "
"if the recessive allele r is lethal, what genotypes will natural selection benefit?",(A) R only (B) RR only (C) RR and Rr (D) Rr and rr,C,"Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa, for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the populations gene pool. The gene pool is the complete set of genes and alleles within a population. For example, Tay-Sachs disease is a recessive human genetic disorder. That means only individuals with the homozygous recessive genotype, rr will be affected. Affected individuals usually die from complications of the disease in early childhood, at an age too young to reproduce. The two parents are each heterozygous (Rr) for the Tay-Sachs gene; they will not die in childhood and will be carriers of the disease gene. This deadly allele is kept in the gene pool even though it does not help humans adapt to their environment. This happens because evolution acts on the phenotype, not the genotype ( Figure 1.1). Tay-Sachs disease is inherited in the au- tosomal recessive pattern. Each parent is an unaffected carrier of the lethal allele. "
natural selection acts on _________________________.,(A) heterozygous individuals (B) homozygous individuals (C) the phenotype (D) the genotype,C,"Natural selection acts on the phenotype (the traits or characteristics) of an individual. On the other hand, natural selection does not act on the underlying genotype (the genetic makeup) of an individual. For many traits, the homozygous genotype, AA, for example, has the same phenotype as the heterozygous Aa genotype. If both an AA and Aa individual have the same phenotype, the environment cannot distinguish between them. So natural selection cannot select for a homozygous individual over a heterozygous individual. Even if the ""aa"" phenotype is lethal, the recessive a allele, will be maintained in the population through heterozygous Aa individuals. Furthermore, the mating of two heterozygous individuals can produce homozygous recessive (aa) individuals. However, natural selection can and does differentiate between dominant and recessive phenotypes. "
why dont individuals with tay-sachs pass on the tay-sachs allele?,(A) Because Tay-Sachs disease is a recessive human genetic disorder (B) Because carriers are not affected (C) Because affected individuals do not have children (D) all of the above For	questions	9	and	10 (E) use	the	following	information	 In	the	fictional	hobbit (F) there	exist	5	alleles	of	the	foot	size	gene:	F1	-	F5	Each	 allele	is	dominant	over	an	allele	with	a	higher	number	For	example	F3	is	 dominant	over	F4 (G) and	F4	is	dominant	over	F5	F5	is	recessive	to	all	other	F	 alleles (H) and	results	in	a	hobbled	hobbit	This	is	usually	a	lethal	phenotype,C,"Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa, for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the populations gene pool. The gene pool is the complete set of genes and alleles within a population. For example, Tay-Sachs disease is a recessive human genetic disorder. That means only individuals with the homozygous recessive genotype, rr will be affected. Affected individuals usually die from complications of the disease in early childhood, at an age too young to reproduce. The two parents are each heterozygous (Rr) for the Tay-Sachs gene; they will not die in childhood and will be carriers of the disease gene. This deadly allele is kept in the gene pool even though it does not help humans adapt to their environment. This happens because evolution acts on the phenotype, not the genotype ( Figure 1.1). Tay-Sachs disease is inherited in the au- tosomal recessive pattern. Each parent is an unaffected carrier of the lethal allele. "
how does the f5 allele stay in the gene pool?,(A) All heterozygous genotypes with an F5 allele are carriers (B) All F5 homozygous individuals are selected for by natural selection (C) The F5F5 hobbit is selected for by natural selection (D) all of the above,A,"Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa, for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the populations gene pool. The gene pool is the complete set of genes and alleles within a population. For example, Tay-Sachs disease is a recessive human genetic disorder. That means only individuals with the homozygous recessive genotype, rr will be affected. Affected individuals usually die from complications of the disease in early childhood, at an age too young to reproduce. The two parents are each heterozygous (Rr) for the Tay-Sachs gene; they will not die in childhood and will be carriers of the disease gene. This deadly allele is kept in the gene pool even though it does not help humans adapt to their environment. This happens because evolution acts on the phenotype, not the genotype ( Figure 1.1). Tay-Sachs disease is inherited in the au- tosomal recessive pattern. Each parent is an unaffected carrier of the lethal allele. "
what alleles of the foot size gene are part of the gene pool?,(A) only the dominant alleles (B) F1 and F2 only (C) F1 (D) F2 (E) F3 and F4 (F) d all 5 F alleles,D,"Recall that our DNA is wound into chromosomes. Each of our chromosomes contains a long chain of DNA that encodes hundreds, if not thousands, of genes. Each of these genes can have slightly different versions from individual to individual. These variants of genes are called alleles. Each parent only donates one allele for each gene to an offspring. For example, remember that for the height gene in pea plants there are two possible factors. These factors are alleles. There is a dominant allele for tallness (T) and a recessive allele for shortness (t). "
the excretory system includes organs that are also components of other organ systems.,(A) true (B) false,A,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
urine is a waste formed by the kidneys.,(A) true (B) false,A,"Urine is a liquid that is formed by the kidneys when they filter wastes from the blood. Urine contains mostly water, but it also contains salts and nitrogen-containing molecules. The amount of urine released from the body depends on many things. Some of these include the amount of fluid and food a person consumes and how much fluid they have lost from sweating and breathing. Urine ranges from colorless to dark yellow but is usually a pale yellow color. Light yellow urine contains mostly water. The darker the urine, the less water it contains. The urinary system also removes a type of waste called urea from your blood. Urea is a nitrogen-containing molecule that is made when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea and other wastes are carried in the bloodstream to the kidneys, where they are removed and form urine. "
what part of the excretory system is also part of the urinary system?,(A) the lungs (B) the skin (C) the large intestine (D) the kidneys,D,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
what part of the excretory system is also part of the integumentary system?,(A) the lungs (B) the skin (C) the large intestine (D) the kidneys,B,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
what organ of the excretory system removes solid waste?,(A) the lungs (B) the skin (C) the large intestine (D) the kidneys,C,"So what happens to your bodys wastes? Obviously, you must get rid of them. This is the job of the excretory system. You remove waste as a gas (carbon dioxide), as a liquid (urine and sweat), and as a solid. Excretion is the process of removing wastes and excess water from the body. Recall that carbon dioxide travels through the blood and is transferred to the lungs where it is exhaled. In the large intestine, the remains of food are turned into solid waste for excretion. How is waste other than carbon dioxide removed from the blood? That is the role of the kidneys. Urine is a liquid waste formed by the kidneys as they filter the blood. If you are getting plenty of fluids, your urine should be almost clear. But you might have noticed that sometimes your urine is darker than usual. Do you know why this happens? Sometimes your body is low on water and trying to reduce the amount of water lost in urine. Therefore, your urine gets darker than usual. Your body is striving to maintain homeostasis through the process of excretion. Urine helps remove excess water, salts, and nitrogen from your body. Your body also needs to remove the wastes that build up from cell activity and from digestion. If these wastes are not removed, your cells can stop working, and you can get very sick. The organs of your excretory system help to release wastes from the body. The organs of the excretory system are also parts of other organ systems. For example, your lungs are part of the respiratory system. Your lungs remove carbon dioxide from your body, so they are also part of the excretory system. More organs of the excretory system are listed below ( Table 1.1). Organ(s) Function Lungs Skin Remove carbon dioxide. Sweat glands remove water, salts, and other wastes. Removes solid waste and some wa- ter in the form of feces. Remove urea, salts, and excess wa- ter from the blood. Large intestine Kidneys Component of Other Organ Sys- tem Respiratory system Integumentary system Digestive system Urinary system "
what is the function of the lungs in excretion?,(A) to remove oxygen (B) to remove carbon dioxide (C) to exchange gases (D) all of the above,B,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
what is the function of the skin in excretion?,(A) to remove water (B) salts (C) and other wastes (D) b to remove urea (E) salts (F) and excess water (G) c to remove nitrogen and excess water (H) d to remove excess nutrients and other wastes,A,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
men get more uti than women.,(A) true (B) false,B,"Urinary tract infections (UTIs) are bacterial infections of any part of the urinary tract. When bacteria get into the bladder or kidney and produce more bacteria in the urine, they cause a UTI. The most common type of UTI is a bladder infection. Women get UTIs more often than men. UTIs are often treated with antibiotics. Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the bloodstream, a condition called septicemia. What are the signs and symptoms of a UTI? a burning feeling when you urinate, frequent or intense urges to urinate, even when you have little urine to pass, pain in your back or side below the ribs, cloudy, dark, bloody, or foul-smelling urine, fever or chills. You should see your doctor if you have signs of a UTI. Your doctor will diagnose a UTIs by asking about your symptoms and then testing a sample of your urine. "
most utis are not serious.,(A) true (B) false,A,"Urinary tract infections (UTIs) are bacterial infections of any part of the urinary tract. When bacteria get into the bladder or kidney and produce more bacteria in the urine, they cause a UTI. The most common type of UTI is a bladder infection. Women get UTIs more often than men. UTIs are often treated with antibiotics. Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the bloodstream, a condition called septicemia. What are the signs and symptoms of a UTI? a burning feeling when you urinate, frequent or intense urges to urinate, even when you have little urine to pass, pain in your back or side below the ribs, cloudy, dark, bloody, or foul-smelling urine, fever or chills. You should see your doctor if you have signs of a UTI. Your doctor will diagnose a UTIs by asking about your symptoms and then testing a sample of your urine. "
what is the goal of dialysis?,(A) to filter the blood when the kidneys cannot (B) to remove the pathogens causing a UTI (C) to replace the kidneys (D) to remove kidney stones,A,"Kidney failure happens when the kidneys cannot remove wastes from the blood. If the kidneys are unable to filter wastes from the blood, the wastes build up in the body. Kidney failure can be caused by an accident that injures the kidneys, the loss of a lot of blood, or by some drugs and poisons. Kidney failure may lead to permanent loss of kidney function. But if the kidneys are not seriously damaged, they may recover. Chronic kidney disease is the slow decrease in kidney function that may lead to permanent kidney failure. A person who has lost kidney function may need to get kidney dialysis. Kidney dialysis is the process of filtering the blood of wastes using a machine. A dialysis machine ( Figure 1.2) filters waste from the blood by pumping the blood through a fake kidney. The filtered blood is then returned to the patients body. "
what causes utis?,(A) UTIs are caused by viruses (B) UTIs are caused by bacteria (C) UTIs occur when minerals in the urine crystallize and stick together (D) UTIs can occur by the loss of blood,B,"Urinary tract infections (UTIs) are bacterial infections of any part of the urinary tract. When bacteria get into the bladder or kidney and produce more bacteria in the urine, they cause a UTI. The most common type of UTI is a bladder infection. Women get UTIs more often than men. UTIs are often treated with antibiotics. Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the bloodstream, a condition called septicemia. What are the signs and symptoms of a UTI? a burning feeling when you urinate, frequent or intense urges to urinate, even when you have little urine to pass, pain in your back or side below the ribs, cloudy, dark, bloody, or foul-smelling urine, fever or chills. You should see your doctor if you have signs of a UTI. Your doctor will diagnose a UTIs by asking about your symptoms and then testing a sample of your urine. "
the most common type of uti is,(A) kidney stone infection (B) a kidney infection (C) a bladder infection (D) an urethra infection,C,"Urinary tract infections (UTIs) are bacterial infections of any part of the urinary tract. When bacteria get into the bladder or kidney and produce more bacteria in the urine, they cause a UTI. The most common type of UTI is a bladder infection. Women get UTIs more often than men. UTIs are often treated with antibiotics. Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the bloodstream, a condition called septicemia. What are the signs and symptoms of a UTI? a burning feeling when you urinate, frequent or intense urges to urinate, even when you have little urine to pass, pain in your back or side below the ribs, cloudy, dark, bloody, or foul-smelling urine, fever or chills. You should see your doctor if you have signs of a UTI. Your doctor will diagnose a UTIs by asking about your symptoms and then testing a sample of your urine. "
causes of kidney failure include,(A) accidents that injure the kidneys (B) some drugs and poisons (C) the loss of a lot of blood (D) all of the above,D,"Kidney failure happens when the kidneys cannot remove wastes from the blood. If the kidneys are unable to filter wastes from the blood, the wastes build up in the body. Kidney failure can be caused by an accident that injures the kidneys, the loss of a lot of blood, or by some drugs and poisons. Kidney failure may lead to permanent loss of kidney function. But if the kidneys are not seriously damaged, they may recover. Chronic kidney disease is the slow decrease in kidney function that may lead to permanent kidney failure. A person who has lost kidney function may need to get kidney dialysis. Kidney dialysis is the process of filtering the blood of wastes using a machine. A dialysis machine ( Figure 1.2) filters waste from the blood by pumping the blood through a fake kidney. The filtered blood is then returned to the patients body. "
which of the following are symptoms of a uti?,(A) a burning feeling when you urinate (B) intense urges to urinate (C) foul-smelling urine (D) all of the above,D,"Urinary tract infections (UTIs) are bacterial infections of any part of the urinary tract. When bacteria get into the bladder or kidney and produce more bacteria in the urine, they cause a UTI. The most common type of UTI is a bladder infection. Women get UTIs more often than men. UTIs are often treated with antibiotics. Most UTIs are not serious, but some infections can lead to serious problems. Long lasting kidney infections can cause permanent damage, including kidney scars, poor kidney function, high blood pressure, and other problems. Some sudden kidney infections can be life threatening, especially if the bacteria enter the bloodstream, a condition called septicemia. What are the signs and symptoms of a UTI? a burning feeling when you urinate, frequent or intense urges to urinate, even when you have little urine to pass, pain in your back or side below the ribs, cloudy, dark, bloody, or foul-smelling urine, fever or chills. You should see your doctor if you have signs of a UTI. Your doctor will diagnose a UTIs by asking about your symptoms and then testing a sample of your urine. "
members of a species that are clumped together may have a better chance of reproducing.,(A) true (B) false,A,Both types of reproduction have certain advantages. 
birth rate + death rate = growth rate,(A) true (B) false,B,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
10 spiders/square meter is an example of,(A) population size (B) population dispersion (C) population density (D) all of the above,C,"Another sign of a species state of health is the density of its populations. Population density is the average number of individuals in a population for a given area. Density is a measure of how crowded or spread out the individuals in a population are on average. For example, a population of 100 deer that live in an area of 10 square kilometers has a population density of 10 deer per square kilometer. Population density is an average measure. Often, individuals in a population are not spread out evenly. Instead, they may live in clumps or some other pattern. How individuals in a population are distributed, or spread throughout their area, is called population distribution. You can see different patterns of population distribution in Figure 23.3. Different patterns characterize different species and types of environments, as you can read in the figure. "
a population with equal birth and death rates,(A) will grow in size (B) will remain the same size (C) will decrease in size (D) will fluctuate in size,B,"Just as they did in Europe and North America, death rates have fallen throughout the world. No country today remains in Stage 1 of the demographic transition. However, birth rates are still high in many of the poorest countries of the world. These populations seem to be stuck in Stage 2 or 3 of the demographic transition. They have high population growth rates because low death rates are not matched by equally low birth rates. Whether these populations will ever enter Stage 4 and attain very low rates of population growth is uncertain. "
a population of mostly young organisms and a high birth rate will,(A) grow in size (B) decrease in size (C) will stay the same size (D) will grow than drop in size,A,"Population growth rate depends on birth rates and death rates, as well as migration. First, we will consider the effects of birth and death rates. You can predict the growth rate by using this simple equation: growth rate = birth rate death rate. If the birth rate is larger than the death rate, then the population grows. If the death rate is larger than the birth rate, what will happen to the population? The population size will decrease. If the birth and death rates are equal, then the population size will not change. Factors that affect population growth are: 1. 2. 3. 4. 5. 6. Age of organisms at first reproduction. How often an organism reproduces. The number of offspring of an organism. The presence or absence of parental care. How long an organism is able to reproduce. The death rate of offspring. For an ecosystem to be stable, populations in that system must be healthy, and that usually means reproducing as much as their environment allows. Do organisms reproduce yearly or every few years? Do organisms reproduce for much of their life, or just part of their life? Do organisms produce many offspring at once, or just a few, or even just one? Do many newborn organisms die, or do the majority survive? All these factors play a role in the growth of a population. Organisms can use different strategies to increase their reproduction rate. Altricial organisms are helpless at birth, and their parents give them a lot of care. This care is often seen in bird species. ( Figure 1.1). Altricial birds are usually born blind and without feathers. Compared to precocial organisms, altricial organisms have a longer period of development before they reach maturity. Precocial organisms, such as the geese shown below, can take care of themselves at birth and do not require help from their parents ( Figure 1.1). In order to reproduce as much as possible, altricial and precocial organisms must use very different strategies. (left) A hummingbird nest with young il- lustrates an altricial reproductive strategy, with a few small eggs, helpless young, and intensive parental care. (right) The Canada goose shows a precocial repro- ductive strategy. It lays a large number of large eggs, producing well-developed young. "
individuals of zebra may showed clustered dispersion because,(A) this makes hunting easier (B) this offers protection from predators (C) this allows them to save water (D) all of the above,B,"Organisms must be able to get food and avoid being food. Hummingbirds have long, thin beaks that help them drink nectar from flowers. Some flowers are tubular to fit hummingbird beaks. The battle between needing food and being food plays out in the drama between lions and zebras. When a herd of zebras senses a lion, the animals run away. The zebras dark stripes confuse the lions. It becomes hard for them to focus on just one zebra. The zebras may get away. But lions are swift and agile. A lion may be able to get a zebra, maybe one thats old or sick. "
which of the following statements is correct?,(A) Members of the same species that live in the same area can form two different populations (B) Members of two species that live in the same area can form one population (C) Members of two species that live in the same area form two different (D) Individuals of the same species that live in the same area but cannot reproduce form two different populations,C,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
breasts are considered extremely important reproductive organs.,(A) true (B) false,B,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
"a girl is born with over 1,000,000 immature eggs.",(A) true (B) false,A,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after she starts having menstrual periods at about age 12 or 13. Just one egg develops each month. A woman will release an egg once each month until she is in her 40s. A girl is born with over a million eggs. They die off and by puberty about 40,000 remain. "
the vagina is a passageway that connects the uterus to the,(A) ovaries (B) fallopian tubes (C) urethra (D) outside,D,"The female reproductive organs include the vagina, uterus, fallopian tubes, and ovaries ( Figure 1.1). The breasts are not shown in this figure. They are not considered reproductive organs, even though they are involved in reproduction. They contain mammary glands that give milk to feed a baby. The milk leaves the breast through the nipple when the baby sucks on it. The vagina is a cylinder-shaped organ found inside of the female body. One end of the vagina opens at the outside of the body. The other end joins with the uterus. During sexual intercourse, sperm may be released into the vagina. If this occurs, the sperm will move through the vagina and into the uterus. During birth, a baby passes from the uterus to the vagina to leave the body. The uterus is a hollow organ with muscular walls. The part that connects the vagina with the uterus is called the cervix. The uterus is where a baby develops until birth. The walls of the uterus grow bigger as the baby grows. The muscular walls of the uterus push the baby out during birth. This drawing shows the organs of the female reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two ovaries are small, oval organs on either side of the uterus. Each ovary contains thousands of eggs, with about 1-2 million immature eggs present at birth and 40,000 immature eggs present at puberty, as most of the eggs die off. The eggs do not fully develop until a female has gone through puberty. About once a month, on average one egg completes development and is released by the ovary. The ovaries also secrete estrogen, the main female sex hormone. The two fallopian tubes are narrow tubes that open off from the uterus. Each tube reaches for one of the ovaries, but the tubes are not attached to the ovaries. The end of each fallopian tube by the ovary has fingers ( Figure 1.1). They sweep an egg into the fallopian tube. Then the egg passes through the fallopian tube to the uterus. If an egg is to be fertilized, this will occur in the fallopian tube. A fertilized egg then implants into the wall of the uterus, where it begins to develop. An unfertilized egg will flow through the uterus and be excreted from the body. "
what organ secretes estrogen?,(A) the vagina (B) the uterus (C) the ovary (D) the fallopian tube,C,"There are several other endocrine glands. Find them in Figure 20.17 as you read about them below. The thyroid gland is a relatively large gland in the neck. Hormones secreted by the thyroid gland include thyroxin. Thyroxin increases the rate of metabolism in cells throughout the body. The pancreas is a large gland located near the stomach. Hormones secreted by the pancreas include insulin. Insulin helps cells absorb glucose from the blood. It also stimulates the liver to take up and store excess glucose. The two adrenal glands are glands located just above the kidneys. Each adrenal gland has an outer layer (cortex) and inner layer (medulla) that secrete different hormones. The hormone adrenaline is secreted by the inner layer. It prepares the body to respond to emergencies. For example, it increases the amount of oxygen and glucose going to the muscles. The gonads are glands that secrete sex hormones. Male gonads are called testes. They secrete the male sex hormone testosterone. The female gonads are called ovaries. They secrete the female sex hormone estrogen. Sex hormones stimulate the changes of puberty. They also control the production of sperm or eggs by the gonads. "
where does fertilization occur?,(A) the vagina (B) the uterus (C) the ovary (D) the fallopian tube,D,"The blastocyst continues down the fallopian tube until it reaches the uterus, about 4 or 5 days after fertilization. When the outer cells of the blastocyst contact cells lining the uterus (the endometrium in Figure 22.5), the blastocyst embeds itself in the uterine lining. This process is called implantation. It generally occurs about a week after fertilization. "
about how many eggs does a girl have when she begins puberty?,(A) about 50 (B) about 100 (C) about 1 (D) 000 (E) d over 25 (F) 000,D,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after the female reaches puberty at about age 12 or 13. Then, just one egg develops each month until she reaches her 40s or early 50s. "
where does a baby develop until birth?,(A) the vagina (B) the uterus (C) the fornix (D) the cervix,B,"There are also many changes that take place after the embryo becomes a fetus. Some of the differences between them are obvious. For example, the fetus has ears and eyelids. Its fingers and toes are also fully formed. The fetus even has fingernails and toenails. In addition, the reproductive organs have developed to make the baby a male or female. The brain and lungs are also developing quickly. The fetus has started to move around inside the uterus. This is usually when the mother first feels the fetus moving. By the 28th week, the fetus is starting to look much more like a baby. Eyelashes and eyebrows are present. Hair has started to grow on the head. The body of the fetus is also starting to fill out as muscles and bones develop. Babies born after the 28th week are usually able to survive. However, they need help breathing because their lungs are not yet fully mature. A baby should not be delivered prior to this time, unless absolutely necessary. A baby born prior to week 28 will need considerable medical intervention to survive. During the last several weeks of the fetal period, all of the organs become mature. The most obvious change, however, is an increase in body size. The fetus rapidly puts on body fat and gains weight during the last couple of months. By the end of the 38th week, all of the organs are working, and the fetus is ready to be born. This is when birth normally occurs. A baby born before this time is considered premature. "
all of the eggs a woman will ever have are produced before birth.,(A) true (B) false,A,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after the female reaches puberty at about age 12 or 13. Then, just one egg develops each month until she reaches her 40s or early 50s. "
the female reproductive system prepares itself every week to accept a fertilized egg.,(A) true (B) false,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
a human cell has 46 chromosomes. how many chromosomes are in a human egg?,(A) 92 (B) 46 (C) 23 (D) 2,C,"In species with sexual reproduction, each cell of the body has two copies of each chromosome. For example, human beings have 23 different chromosomes. Each body cell contains two of each chromosome, for a total of 46 chromosomes. You can see the 23 pairs of human chromosomes in Figure 5.13. The number of different types of chromosomes is called the haploid number. In humans, the haploid number is 23. The number of chromosomes in normal body cells is called the diploid number. The diploid number is twice the haploid number. In humans, the diploid number is two times 23, or 46. "
what is the role of estrogen in the adult female?,(A) to release eggs (B) to maintain her reproductive structures (C) to develop female traits (D) all of the above,A,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
"an average, how many eggs does a female release each cycle?",(A) 1 (B) 2 (C) 10 (D) 100,A,"When a baby girl is born, her ovaries contain all of the eggs they will ever produce. But these eggs are not fully developed. They develop only after she starts having menstrual periods at about age 12 or 13. Just one egg develops each month. A woman will release an egg once each month until she is in her 40s. A girl is born with over a million eggs. They die off and by puberty about 40,000 remain. "
what happens to the female reproductive system if an egg is not fertilized?,(A) The system prepares itself to allow the baby to develop (B) The system must prepare itself again in case an egg is fertilized the next (C) The baby begins to grow in the uterus (D) nothing happens,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
which best describes an egg cell?,(A) round with a diploid nucleus (B) round with a haploid nucleus (C) round with lots of cytoplasm (D) round with a flagella tail,B,"Human eggs are very large cells. In fact, they are the largest of all human cells. You can even see an egg without a microscope. Its almost as big as the period at the end of this sentence. Like a sperm cell, an egg cell is a haploid cell with half the number of chromosomes of other cells in the body. Unlike a sperm cell, the egg lacks a tail and contains a lot of cytoplasm. "
anaerobic respiration is less effective than aerobic respiration.,(A) true (B) false,A,"Both aerobic and anaerobic respiration have certain advantages. Aerobic respiration releases far more energy than anaerobic respiration does. It results in the formation of many more molecules of ATP. Anaerobic respiration is much quicker than aerobic respiration. It also allows organisms to live in places where there is little or no oxygen, such as deep under water or soil. For an entertaining review of aerobic and anaerobic respiration, watch this creative music video:  MEDIA Click image to the left or use the URL below. URL: "
"in the absence of oxygen, yeast make alcohol.",(A) true (B) false,A,"In alcoholic fermentation, glycolysis is followed by a step that produces alcohol and carbon dioxide. This step also forms additional molecules of ATP. It occurs in yeast, such as the yeast in bread. Carbon dioxide from alcoholic fermentation creates gas bubbles in bread dough. The bubbles leave little holes in the bread after it bakes. You can see them in the bread in Figure 4.16. The holes make the bread light and fluffy. "
how many times more effective is aerobic respiration compared to anaerobic respiration?,(A) 2x (B) 9x (C) 18x (D) 36x,C,"Both aerobic and anaerobic respiration have certain advantages. Aerobic respiration releases far more energy than anaerobic respiration does. It results in the formation of many more molecules of ATP. Anaerobic respiration is much quicker than aerobic respiration. It also allows organisms to live in places where there is little or no oxygen, such as deep under water or soil. For an entertaining review of aerobic and anaerobic respiration, watch this creative music video:  MEDIA Click image to the left or use the URL below. URL: "
what is the main goal of fermentation?,(A) to produce two ATP (B) to allow glycolysis to occur (C) to make alcohol (D) to produce lactic acid,B,"Sometimes cells need to obtain energy from sugar, but there is no oxygen present to complete cellular respiration. In this situation, cellular respiration can be anaerobic, occurring in the absence of oxygen. In this process, called fermentation, only the first step of respiration, glycolysis, occurs, producing two ATP; no additional ATP is produced. Therefore, the organism only obtains the two ATP molecules per glucose molecule from glycolysis. Compared to the 36-38 ATP produced under aerobic conditions, anaerobic respiration is not a very efficient process. Fermentation allows the first step of cellular respiration to continue and produce some ATP, even without oxygen. Yeast (single-celled eukaryotic organisms) perform alcoholic fermentation in the absence of oxygen. The products of alcoholic fermentation are ethyl alcohol (drinking alcohol) and carbon dioxide gas. This process is used to make common food and drinks. For example, alcoholic fermentation is used to bake bread. The carbon dioxide bubbles allow the bread to rise and become fluffy. Meanwhile, the alcohol evaporates. In wine making, the sugars of grapes are fermented to produce wine. The sugars are the starting materials for glycolysis. Animals and some bacteria and fungi carry out lactic acid fermentation. Lactic acid is a waste product of this process. Our muscles perform lactic acid fermentation during strenuous exercise, since oxygen cannot be delivered to the muscles quickly enough. The buildup of lactic acid is believed to make your muscles sore after exercise. Bacteria that produce lactic acid are used to make cheese and yogurt. The lactic acid causes the proteins in milk to thicken. Lactic acid also causes tooth decay, because bacteria use the sugars in your mouth for energy. Pictured below are some products of fermentation ( Figure 1.1). Products of fermentation include cheese (lactic acid fermentation) and wine (alco- holic fermentation). "
what organisms perform lactic acid fermentation under anaerobic conditions?,(A) plants (B) animals (C) fungi (D) both (b,D,"In lactic acid fermentation, glycolysis is followed by a step that produces lactic acid. This step forms additional molecules of ATP. Lactic acid fermentation occurs in some bacteria, including the bacteria in yogurt. The lactic acid gives unsweetened yogurt its sour taste. Your own muscle cells can also undertake lactic acid fermentation. This occurs when the cells are working very hard. They use fermentation because they cant get oxygen fast enough for aerobic respiration to supply them with all the energy they need. The muscle cells of the hurdlers in Figure 4.15 are using lactic acid fermentation by the time the athletes reach finish line. "
lactic acid fermentation is used to make which of the following products?,(A) drinking alcohol (B) bread (C) yogurt (D) all of the above,C,"In lactic acid fermentation, glycolysis is followed by a step that produces lactic acid. This step forms additional molecules of ATP. Lactic acid fermentation occurs in some bacteria, including the bacteria in yogurt. The lactic acid gives unsweetened yogurt its sour taste. Your own muscle cells can also undertake lactic acid fermentation. This occurs when the cells are working very hard. They use fermentation because they cant get oxygen fast enough for aerobic respiration to supply them with all the energy they need. The muscle cells of the hurdlers in Figure 4.15 are using lactic acid fermentation by the time the athletes reach finish line. "
what process allows bread to rise?,(A) aerobic respiration (B) lactic acid fermentation (C) alcoholic fermentation (D) photosynthesis,C,"In alcoholic fermentation, glycolysis is followed by a step that produces alcohol and carbon dioxide. This step also forms additional molecules of ATP. It occurs in yeast, such as the yeast in bread. Carbon dioxide from alcoholic fermentation creates gas bubbles in bread dough. The bubbles leave little holes in the bread after it bakes. You can see them in the bread in Figure 4.16. The holes make the bread light and fluffy. "
whales are the biggest fish.,(A) true (B) false,B,"Fish range in size from the 65-foot, 75,000 pound whale shark ( Figure 1.3) to the stout infantfish, which is about 0.33 inches (8.4 mm), and the Paedocypris progenetica carp species of the Indonesian island of Sumatra, which is about 0.31 inches (7.9 mm) long, making it also the smallest known vertebrate animal. The second-largest fish is the basking shark, which grows to about 40 feet and 8,000 pounds. Both of the large sharks may look ferocious, and would probably scare anyone who comes across one in the water, but both species are filter-feeders, and feed on tiny fish and plankton. The tiny carp species is unique in that it has the appearance of larvae, with a reduced skeleton lacking a cranium, which leaves the brain unprotected by bone. The fish lives in dark acidic waters, having a pH of 3. Keep in mind that whales are not fish, they are mammals. "
some fish can live on land for short periods.,(A) true (B) false,A,"An organism that lives in water is supported by the water. It does not need strong support structures. It also does not need to be protected against drying out. This is not true of land. Moving from the seas to land required many adaptations. Algae had covered moist land areas for millions of years. By about 450 million years ago, plants began to appear on land. Once there were land plants, animals had a source of food and shelter. To move to land, animals needed strong skeletons. They needed protection from drying out. They needed to be able to breathe air. Eventually they had skeletons, lungs and the other the adaptations they needed moved onto the land. One group of fish evolved into amphibians. Insects and spiders were already land dwellers by the time amphibians appeared. "
ectothermy is a characteristic of fish? what is ectothermy?,(A) Being cold-blooded (B) Not being able to raise body temperature without help (C) Being dependent on the environment to maintain body temperature (D) all of the above,D,Fish are aquatic vertebrates. They make up more than half of all living vertebrate species. Most fish are ectothermic. They share several adaptations that suit them for life in the water. 
what is a unique characteristic of some cartilaginous fish?,(A) They are not endothermic (B) They have very flexible pectoral fins (C) They reproduce asexually (D) all of the above,B,"The 1,000 or so species of cartilaginous fish are subdivided into two subclasses: the first includes sharks, rays, and skates; the second includes chimaera, sometimes called ghost sharks. Fish from this group range in size from the dwarf lanternshark, at 6.3 inches, to the over 50-foot whale shark. Sharks obviously have jaws, as do the other cartilaginous fish. These fish evolved from the jawless fish. So why did fish eventually evolve to have jaws? Such an adaptation would allow fish to eat a much wider variety of food, including plants and other organisms. Other characteristics of cartilaginous fish include: Paired fins. Paired nostrils. Scales. Two-chambered hearts. Skeletons made of cartilage rather than bone. Cartilage is supportive tissue that does not have as much calcium as bones, which makes bones rigid. Cartilage is softer and more flexible than bone. "
what is a unique characteristic of tuna and swordfish?,(A) They are not covered with scales (B) They are able to raise their body temperature above that of the surrounding (C) They breathe using either gills or lungs (D) all of the above,B,"There are exceptions to many of these fish traits. For example, tuna, swordfish, and some species of shark show some warm-blooded adaptations and are able to raise their body temperature significantly above that of the water around them. Some species of fish have a slower, more maneuverable swimming style, like eels and rays ( Figure 1.4). Body shape and the arrangement of fins are highly variable, and the surface of the skin may be naked, as in moray eels, or covered with scales. Scales can be of a variety of different types. "
what do the two biggest fish have in common?,(A) Both are fierce rulers of their habitat (B) Both are filter feeders (C) Both are ferocious carnivores (D) all of the above,B,"Fish range in size from the 65-foot, 75,000 pound whale shark ( Figure 1.3) to the stout infantfish, which is about 0.33 inches (8.4 mm), and the Paedocypris progenetica carp species of the Indonesian island of Sumatra, which is about 0.31 inches (7.9 mm) long, making it also the smallest known vertebrate animal. The second-largest fish is the basking shark, which grows to about 40 feet and 8,000 pounds. Both of the large sharks may look ferocious, and would probably scare anyone who comes across one in the water, but both species are filter-feeders, and feed on tiny fish and plankton. The tiny carp species is unique in that it has the appearance of larvae, with a reduced skeleton lacking a cranium, which leaves the brain unprotected by bone. The fish lives in dark acidic waters, having a pH of 3. Keep in mind that whales are not fish, they are mammals. "
what is significant about the smallest vertebrate?,(A) It does not have a cranium (B) It is not a true fish (C) It does not use gills to breathe (D) It does not have fins,A,"The primary feature shared by all vertebrates is the vertebral column, or backbone. The vertebral column protects the spinal cord. Other typical vertebrate traits include: The cranium (skull) to protect the brain. The brain is attached to the spinal cord. An internal skeleton. The internal skeleton supports the animal, protects internal organs, and allows for movement. A defined head region with a brain. The head region has an accumulation of sense organs. Living vertebrates range in size from a carp species, as little as 0.3 inches, to the blue whale, which can be as large as 110 feet ( Figure 1.1). A species of carp and an image of the blue whale (a mammal), the largest liv- ing vertebrate, reaching up to 110 feet long. Shown below it is the smallest whale species, Hectors dolphin (about 5 feet in length), and beside it is a human. These images are not to scale. The carp is greatly exaggerated in size and is even smaller than depicted when compared to the blue whale. "
the flatworms are the first significant phylum with bilateral symmetry.,(A) true (B) false,A,"The word ""worm"" is not very scientific. But it is a word that informally describes animals (usually invertebrates) that have long bodies with no arms or legs. (Snakes are vertebrates, so they are not usually described as worms.) Worms are the first significant group of animals with bilateral symmetry, meaning that the right side of their bodies is a mirror of the left. One type of worm is the flatworm. Worms in the phylum Platyhelminthes are called flatworms because they have flattened bodies. There are more than 18,500 known species of flatworms. "
most flatworms are parasites.,(A) true (B) false,A,"Some flatworms live in water or moist soil. They eat invertebrates and decaying animals. Other flatworms, such as tapeworms, are parasites that live inside vertebrate hosts. Usually, more than one type of host is needed to complete the parasites life cycle, as shown in Figure 12.12. "
how does respiration occur in flatworms?,(A) Respiration occurs by the movement of oxygen over the gills (B) Respiration occurs by the diffusion of oxygen into the lungs (C) Respiration occurs by the diffusion of oxygen into the worm body (D) All of the above methods are used by worms to respire,C,"The main characteristics of flatworms ( Figure 1.1) include: 1. Flatworms have no true body cavity, but they do have bilateral symmetry. Due to the lack of a body cav- ity,flatworms are known as acoelomates. 2. Flatworms have an incomplete digestive system. This means that the digestive tract has only one opening. Digestion takes place in the gastrovascular cavity. 3. Flatworms do not have a respiratory system. Instead, they have pores that allow oxygen to enter through their body. Oxygen enters the pores by diffusion. 4. There are no blood vessels in the flatworms. Their gastrovascular cavity helps distribute nutrients throughout the body. 5. Flatworms have a ladder-like nervous system; two interconnected parallel nerve cords run the length of the body. 6. Most flatworms have a distinct head region that includes nerve cells and sensory organs, such as eyespots. The development of a head region, called cephalization, evolved at the same time as bilateral symmetry in animals. This process does not occur in cnidarians, which evolved prior to flatworms and have radial symmetry. Marine flatworms can be brightly colored, such as this one from the class Turbel- laria. These worms are mostly carnivores or scavengers. "
what is cephalization?,(A) Cephalization is the development of a head region (B) Cephalization refers to the flatworms head region (C) Cephalization includes the two eye spots (D) Cephalization is the development of the nerve net running the length of the flatworm body,A,"Cephalopods include the octopus and squid. They have a prominent head and a well-developed brain. Typically the foot has been modified into a set of arms or tentacles. Members of this class can change color. They can also change texture and body shape, and, and if those camouflage techniques dont work, they can still ""disappear"" in a cloud of ink. Cephalopods have three hearts that pump blue blood, theyre jet powered by their muscular foot, and theyre found in all oceans of the world. Cephalopods are thought to be the most intelligent of invertebrates. They have eyes and other senses that rival those of humans. Many cephalopods are active and efficient predators. What features do you think allows for this? (left) An example of a gastropod species, the ostrich foot. (right) A Caribbean reef squid, an example of a cephalopod. "
how are nutrients distributed throughout the flatworm?,(A) Nutrients are carried by the blood through the flatworm (B) Nutrients are distributed by diffusion (C) Nutrients are distributed by the digestive tract (D) Nutrients are distributed by the gastrovascular cavity,D,"1. Unlike the flatworms, the roundworms have a body cavity with internal organs. 2. A roundworm has a complete digestive system, which includes both a mouth and an anus. This is a significant difference from the incomplete digestive system of flatworms. The roundworm digestive system also include a large digestive organ known as the gut. Digestive enzymes that start to break down food are produced here. There is no stomach, but there is an intestine which produces enzymes that help absorb nutrients. The last portion of the intestine forms a rectum, which expels waste through the anus. 3. Roundworms also have a simple nervous system with a primitive brain. There are four nerves that run the length of the body and are connected from the top to the bottom of the body. At the anterior end of the animal (the head region), the nerves branch from a circular ring which serves as the brain. The head of a nematode has a few tiny sense organs, including chemoreceptors, which sense chemicals. Though still a relatively simple structure, the nervous system of roundworms is very different from that of the cnidarian nerve net. "
which best describes the flatworm digestive system?,(A) Flatworms have a complete digestive system (B) with two openings (C) a mouth and an anus (D) b Flatworms have an incomplete digestive system (E) with two openings (F) a mouth and an anus (G) c Flatworms have an incomplete digestive system (H) with just one opening (I) d Flatworms do not have a digestive system,C,"The main characteristics of flatworms ( Figure 1.1) include: 1. Flatworms have no true body cavity, but they do have bilateral symmetry. Due to the lack of a body cav- ity,flatworms are known as acoelomates. 2. Flatworms have an incomplete digestive system. This means that the digestive tract has only one opening. Digestion takes place in the gastrovascular cavity. 3. Flatworms do not have a respiratory system. Instead, they have pores that allow oxygen to enter through their body. Oxygen enters the pores by diffusion. 4. There are no blood vessels in the flatworms. Their gastrovascular cavity helps distribute nutrients throughout the body. 5. Flatworms have a ladder-like nervous system; two interconnected parallel nerve cords run the length of the body. 6. Most flatworms have a distinct head region that includes nerve cells and sensory organs, such as eyespots. The development of a head region, called cephalization, evolved at the same time as bilateral symmetry in animals. This process does not occur in cnidarians, which evolved prior to flatworms and have radial symmetry. Marine flatworms can be brightly colored, such as this one from the class Turbel- laria. These worms are mostly carnivores or scavengers. "
a body cavity usually refers to the space located between an animals outer covering and the outer lining of the gut cavity. coelomates have a complete body cavity where organs attach and develop. pseudocoelomates have a body cavity that loosely holds organs in place. acoelomates do not have a body cavity. what type of animals are flatworms?,(A) coelomates (B) pseudocoelomates (C) acoelomates (D) none of the above,A,"The next major animal trait to evolve was a body cavity filled with fluid. At first, this was just a partial body cavity, called a pseudocoelom. A pseudocoelom isnt completely enclosed by mesoderm. However, it still allows room for internal organs to develop. The fluid in the cavity also cushions the internal organs. The pressure of the fluid provides stiffness as well. It gives the body internal support. Modern invertebrates with a pseudocoelom include roundworms. Flatworms lack this trait. This difference explains why roundworms are round whereas flatworms are flat. Later, a true coelom evolved. This is a fluid-filled body cavity that is completely enclosed by mesoderm. The coelom lies between the digestive cavity and body wall. You can see it in the invertebrate in Figure 11.9. Modern invertebrates with a coelom include mollusks (Phylum Mollusca) and annelids (Phylum Annelida). "
there are more carbohydrates in a salad than in a steak.,(A) true (B) false,A,"Starch is a large, complex carbohydrate made of thousands of glucose units (monomers) joined together. Starches are found in foods such as vegetables and grains. Starches are broken down by the body into sugars that provide energy. Breads and pasta are good sources of complex carbohydrates. Fiber is another type of large, complex carbohydrate that is partly indigestible. Unlike sugars and starches, fiber does not provide energy. However, it has other important roles in the body. For example, fiber is important for maintaining the health of your gastrointestinal tract. Eating foods high in fiber also helps fill you up without providing too many calories. Most fruits and vegetables are high in fiber. Some examples are pictured below ( Figure 1.2). "
"the four types of nutrients are carbohydrates, lipids, proteins and nucleic acids.",(A) true (B) false,B,"There are a variety of substances in foods that the body needs. Any substance in food that the body needs is called a nutrient. There are six major types of nutrients: carbohydrates, proteins, lipids, water, minerals, and vitamins. Carbohydrates, proteins, and lipids can be used for energy. Proteins also provide building materials. Proteins, minerals, and vitamins help control body processes. Water is needed by all cells just to stay alive. The six types of nutrients can be divided into two major categories based on how much of them the body needs. The categories are macronutrients and micronutrients. "
what is the main source of energy for your body?,(A) lipids (B) proteins (C) carbohydrates (D) nucleic acids,C,"Carbohydrates, proteins, and lipids contain energy. When your body digests food, it breaks down the molecules of these nutrients. This releases the energy so your body can use it. "
which of the following are proteins built from amino acids?,(A) enzymes (B) antibodies (C) and muscle fibers (D) b DNA and RNA (E) c glucose and starch (F) d olive oil,A,"Proteins are molecules that have many different functions in living things. All proteins are made of monomers called amino acids ( Figure 1.2) that connect together like beads on a necklace ( Figure 1.3). There are only 20 common amino acids needed to build proteins. These amino acids form in thousands of different combinations, making about 100,000 or more unique proteins in humans. Proteins can differ in both the number and order of amino acids. It is the number and order of amino acids that determines the shape of the protein, and it is the shape (structure) of the protein that determines the unique function of the protein. Small proteins have just a few hundred amino acids. The largest proteins have more than 25,000 amino acids. This model shows the general structure of all amino acids. Only the side chain, R, varies from one amino acid to another. KEY: H = hydrogen, N = nitrogen, C = carbon, O = oxygen, R = variable side chain. Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as ""biological catalysts."" For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure 1.4). Muscle fibers are made mostly of protein. Its important for you and other animals to eat food with protein, because we cannot make certain amino acids on our own. You can get proteins from plant sources, such as beans, and from animal sources, like milk or meat. When you eat food with protein, your body breaks the proteins down into individual amino acids and uses them to build new proteins. You really are what you eat! "
what type of food provides lipids?,(A) pizza (B) broccoli (C) peanut oil (D) hot dog,C,"Lipids are nutrients such as fats. They are used for energy and other important purposes. One gram of lipids provides the body with 9 Calories of energy, more than twice as much as carbohydrates or proteins. Lipids also make up cell membranes, protect nerves, control blood pressure, and help blood clot. You must consume some lipids for these purposes. Good food sources of lipids are shown in Figure 17.4. Any extra lipids you consume are stored as fat. A certain amount of stored fat is needed to cushion and protect internal organs and insulate the body. However, too much stored fat can lead to obesity and cause significant health problems. A type of lipid called trans fat is found in many processed foods. Trans fat is rare in nature but is manufactured and added to foods to preserve freshness. Eating foods that contain trans fat increases the risk of heart disease. Trans fat may be found in such foods as cookies, doughnuts, crackers, fried foods, ground beef, and margarine. "
what process turns glucose into usable energy?,(A) cellular respiration (B) photosynthesis (C) digestion (D) metabolism,A,"Cellular respiration is the process of extracting energy in the form of ATP from the glucose in the food you eat. How does cellular respiration happen inside of the cell? Cellular respiration is a three step process. Briefly: 1. In stage one, glucose is broken down in the cytoplasm of the cell in a process called glycolysis. 2. In stage two, the pyruvate molecules are transported into the mitochondria. The mitochondria are the organelles known as the energy ""powerhouses"" of the cells (Figure 1.1). In the mitochondria, the pyruvate, which have been converted into a 2-carbon molecule, enter the Krebs cycle. Notice that mitochondria have an inner membrane with many folds, called cristae. These cristae greatly increase the membrane surface area where many of the cellular respiration reactions take place. 3. In stage three, the energy in the energy carriers enters an electron transport chain. During this step, this energy is used to produce ATP. Oxygen is needed to help the process of turning glucose into ATP. The initial step releases just two molecules of ATP for each glucose. The later steps release much more ATP. Most of the reactions of cellular respira- tion are carried out in the mitochondria. "
why does your body need food?,(A) Food provides building materials for your body (B) Food contains substances that help control body processes (C) Food gives your body energy (D) all of the above,D,Your body needs food for three purposes: 1. Food gives the body energy. You need energy for everything you do. The energy in food is measured in a unit called the Calorie. 2. Food provides building materials for the body. The body needs building materials for growth and repair. 3. Food contains substances that help control body processes. Body processes must be kept in balance for good health. 
"fossils are the preserved remains of animals, plants, and other organisms from the distant past.",(A) true (B) false,A,"Fossils are the preserved remains or traces of organisms that lived during earlier ages. Remains that become fossils are generally the hard parts of organismsmainly bones, teeth, or shells. Traces include any evidence of life, such as footprints like the dinosaur footprint in Figure 7.7. Fossils are like a window into the past. They provide direct evidence of what life was like long ago. A scientist who studies fossils to learn about the evolution of living things is called a paleontologist. "
fossiltologists are scientists who study fossils to learn about life in the past.,(A) true (B) false,B,"Fossils are the preserved remains of animals, plants, and other organisms from the distant past. Examples of fossils include bones, teeth, and impressions. By studying fossils, evidence for evolution is revealed. Paleontologists are scientists who study fossils to learn about life in the past. Fossils allow these scientists to determine the features of extinct species. Paleontologists compare the features of species from different periods in history. With this information, they try to understand how species have evolved over millions of years ( Figure below). Until recently, fossils were the main source of evidence for evolution ( Figure below). Through studying fossils, we now know that todays organisms look much different in many cases than those that were alive in the past. Scientists have also shown that organisms were spread out differently across the planet. Earthquakes, volcanoes, shifting seas, and other movements of the continents have all affected where organisms live and how they adapted to their changing environments. "
which best describes radiometric dating?,(A) Measures the accumulation of radiometric materials in a sample (B) Measures the breakdown of radioactive materials in a sample (C) Dates material by measuring radiometric samples (D) Dates material by measuring the breakdown of radioactive samples,B,Radiometric dating is the process of using the concentrations of radioactive substances and daughter products to estimate the age of a material. Different isotopes are used to date materials of different ages. Using more than one isotope helps scientists to check the accuracy of the ages that they calculate. 
which statement describes the order of materials in the fossil record?,(A) Newer layers form on top of the older layers (B) Newer fossils form on top of the older fossils (C) Older fossils form on top of the newer fossils (D) Older layers form on top of the newer layers,B,"Other scientists observed rock layers and formulated other principles. Geologist William Smith (1769-1839) identified the principle of faunal succession, which recognizes that: Some fossil types are never found with certain other fossil types (e.g. human ancestors are never found with dinosaurs) meaning that fossils in a rock layer represent what lived during the period the rock was deposited. Older features are replaced by more modern features in fossil organisms as species change through time; e.g. feathered dinosaurs precede birds in the fossil record. Fossil species with features that change distinctly and quickly can be used to determine the age of rock layers quite precisely. Scottish geologist, James Hutton (1726-1797) recognized the principle of cross-cutting relationships. This helps geologists to determine the older and younger of two rock units (Figure 1.2). If an igneous dike (B) cuts a series of metamorphic rocks (A), which is older and which is younger? In this image, A must have existed first for B to cut across it. "
the oldest rocks on earth are,(A) 1 billion years old (B) 5 billion years old (C) between 3 and 4 billion years old (D) between 4 and 5 billion years old,B,"How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists, and naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: Fossils of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans. The many layers of rock. When people realized that rock layers represent the order in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth. Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earths surface. This supported the idea of an older Earth. The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years. "
the fossil record provides evidence for,(A) when organisms lived on Earth (B) how some species have gone extinct (C) how species evolved (D) all of the above,D,"Fossils are our best form of evidence about Earth history, including the history of life. Along with other geological evidence from rocks and structures, fossils even give us clues about past climates, the motions of plates, and other major geological events. Since the present is the key to the past, what we know about a type of organism that lives today can be applied to past environments. "
the oldest fossils on earth are,(A) 1 million years old (B) 1 billion years old (C) between 3 and 4 billion years old (D) between 4 and 5 billion years old,C,There is good evidence that life has probably existed on Earth for most of Earths history. Fossils of blue-green algae found in Australia are the oldest fossils of life forms on Earth. They are at least 3.5 billion years old ( Figure 1.1). 
a genetic disorder is due to a mutation in your dna.,(A) true (B) false,A,Sequencing the human genome has increased our knowledge of genetic disorders. Genetic disorders are diseases caused by mutations. Many genetic disorders are caused by mutations in a single gene. Others are caused by abnormal numbers of chromosomes. 
genetic disorders are contagious.,(A) true (B) false,B,"Many genetic disorders are caused by mutations in one or a few genes. Others are caused by chromosomal mutations. Some human genetic disorders are X-linked or Y-linked, which means the faulty gene is carried on these sex chromosomes. Other genetic disorders are carried on one of the other 22 pairs of chromosomes; these chromosomes are known as autosomes or autosomal (non-sex) chromosomes. Some genetic disorders are due to new mutations, others can be inherited from your parents. "
"for a child to have cystic fibrosis, the child had to",(A) inherit two dominant alleles (B) inherit two recessive alleles (C) inherit one dominant and one recessive allele (D) none of the above,B,"Some genetic disorders are caused by recessive alleles of a single gene on an autosome. An example of autosomal recessive genetic disorders are Tay-Sachs disease and cystic fibrosis. Children with cystic fibrosis have excessively thick mucus in their lungs, which makes it difficult for them to breathe. The inheritance of this recessive allele is the same as any other recessive allele, so a Punnett square can be used to predict the probability that two carriers of the disease will have a child with cystic fibrosis. Recall that carriers have the recessive allele for a trait but do not express the trait. What are the possible genotypes of the offspring in the following table ( Table 1.1)? What are the possible phenotypes? F FF (normal) Ff (carrier) F f f Ff (carrier) ff (affected) According to this Punnett square, two parents that are carriers (Ff ) of the cystic fibrosis gene have a 25% chance of having a child with cystic fibrosis (ff ). The affected child must inherit two recessive alleles. The carrier parents are not affected. Tay-Sachs disease is a severe genetic disorder in which affected children do not live to adulthood, so the gene is not passed from an affected individual. Carriers of the Tay-Sachs gene are not affected. How does a child become affected with Tay-Sachs? "
"for a child to have huntingtons disease, the child had to",(A) inherit two dominant alleles (B) inherit two recessive alleles (C) inherit one dominant and one recessive allele (D) none of the above,C,"Huntingtons disease is an example of an autosomal dominant disorder. This means that if the dominant allele is present, then the person will express the disease. A child only has to inherit one dominant allele to have the disease. The disease causes the brains cells to break down, leading to muscle spasms and personality changes. Unlike most other genetic disorders, the symptoms usually do not become apparent until middle age. You can use a simple Punnett square to predict the inheritance of a dominant autosomal disorder, like Huntingtons disease. If one parent has Huntingtons disease, what is the chance of passing it on to the children? If you draw the Punnett square, you will find that there is a 50 percent chance of the disorder being passed on to the children. "
"tay sachs is an autosomal recessive disorder in which affected individuals die in their childhood. for a child to have tay sachs,",(A) both parents must be carriers (B) both parents must have the disease (C) only one parent must have the disease (D) the child must inherit at least one disease allele,A,"Some genetic disorders are caused by recessive alleles of a single gene on an autosome. An example of autosomal recessive genetic disorders are Tay-Sachs disease and cystic fibrosis. Children with cystic fibrosis have excessively thick mucus in their lungs, which makes it difficult for them to breathe. The inheritance of this recessive allele is the same as any other recessive allele, so a Punnett square can be used to predict the probability that two carriers of the disease will have a child with cystic fibrosis. Recall that carriers have the recessive allele for a trait but do not express the trait. What are the possible genotypes of the offspring in the following table ( Table 1.1)? What are the possible phenotypes? F FF (normal) Ff (carrier) F f f Ff (carrier) ff (affected) According to this Punnett square, two parents that are carriers (Ff ) of the cystic fibrosis gene have a 25% chance of having a child with cystic fibrosis (ff ). The affected child must inherit two recessive alleles. The carrier parents are not affected. Tay-Sachs disease is a severe genetic disorder in which affected children do not live to adulthood, so the gene is not passed from an affected individual. Carriers of the Tay-Sachs gene are not affected. How does a child become affected with Tay-Sachs? "
a man with cystic fibrosis marries a normal woman. what is the chance that they will have an affected child?,(A) 0 (B) 25% (C) 50% (D) 100%,A,"Some genetic disorders are caused by recessive alleles of a single gene on an autosome. An example of autosomal recessive genetic disorders are Tay-Sachs disease and cystic fibrosis. Children with cystic fibrosis have excessively thick mucus in their lungs, which makes it difficult for them to breathe. The inheritance of this recessive allele is the same as any other recessive allele, so a Punnett square can be used to predict the probability that two carriers of the disease will have a child with cystic fibrosis. Recall that carriers have the recessive allele for a trait but do not express the trait. What are the possible genotypes of the offspring in the following table ( Table 1.1)? What are the possible phenotypes? F FF (normal) Ff (carrier) F f f Ff (carrier) ff (affected) According to this Punnett square, two parents that are carriers (Ff ) of the cystic fibrosis gene have a 25% chance of having a child with cystic fibrosis (ff ). The affected child must inherit two recessive alleles. The carrier parents are not affected. Tay-Sachs disease is a severe genetic disorder in which affected children do not live to adulthood, so the gene is not passed from an affected individual. Carriers of the Tay-Sachs gene are not affected. How does a child become affected with Tay-Sachs? "
what is the chance that two carriers of the cystic fibrosis allele will have a carrier child?,(A) 0 (B) 25% (C) 50% (D) 100%,A,"Some genetic disorders are caused by recessive alleles of a single gene on an autosome. An example of autosomal recessive genetic disorders are Tay-Sachs disease and cystic fibrosis. Children with cystic fibrosis have excessively thick mucus in their lungs, which makes it difficult for them to breathe. The inheritance of this recessive allele is the same as any other recessive allele, so a Punnett square can be used to predict the probability that two carriers of the disease will have a child with cystic fibrosis. Recall that carriers have the recessive allele for a trait but do not express the trait. What are the possible genotypes of the offspring in the following table ( Table 1.1)? What are the possible phenotypes? F FF (normal) Ff (carrier) F f f Ff (carrier) ff (affected) According to this Punnett square, two parents that are carriers (Ff ) of the cystic fibrosis gene have a 25% chance of having a child with cystic fibrosis (ff ). The affected child must inherit two recessive alleles. The carrier parents are not affected. Tay-Sachs disease is a severe genetic disorder in which affected children do not live to adulthood, so the gene is not passed from an affected individual. Carriers of the Tay-Sachs gene are not affected. How does a child become affected with Tay-Sachs? "
"at genetic equilibrium, there is no evolution.",(A) true (B) false,A,Individuals dont evolve. Their alleles dont change over time. The unit of microevolution is the population. 
genetic equilibrium rarely occurs in nature.,(A) true (B) false,A,"Sometimes understanding how common a gene is within a population is necessary. Or, more specifically, you may want to know how common a certain form of that gene is within the population, such as a recessive form. This can be done using the Hardy-Weinberg model, but it can only be done if the frequencies of the genes are not changing. The Hardy-Weinberg model describes how a population can remain at genetic equilibrium, referred to as the Hardy-Weinberg equilibrium. Genetic equilibrium occurs when there is no evolution within the population. In other words, the frequency of alleles (variants of a gene) will be the same from one generation to another. At genetic equilibrium, the gene or allele frequencies are stablethey do not change. For example, lets assume that red hair is determined by the inheritance of a gene with two allelesR and r. The dominant allele, R, encodes for non-red hair, while the recessive allele, r, encodes for red hair. If a populations gene pool contains 90% R and 10% r alleles, then the next generation would also have 90% R and 10% r alleles. However, this only works under a strict set of conditions. The five conditions that must be met for genetic equilibrium to occur include: 1. 2. 3. 4. 5. No mutation (change) in the DNA sequence. No migration (moving into or out of a population). A very large population size. Random mating. No natural selection. These five conditions rarely occur in nature. When one or more of the conditions does not exist, then evolution can occur. As a result, allele frequencies are constantly changing, and populations are constantly evolving. As mutations and natural selection occur frequently in nature, it is difficult for a population to be at genetic equilibrium. The Hardy-Weinberg model also serves a mathematical formula used to predict allele frequencies in a population at genetic equilibrium. If you know the allele frequencies of one generation, you can use this formula to predict the next generation. Again, this only works if all five conditions are being met in a population. "
which of the following are conditions for hardy-weinberg equilibrium?,(A) no mutations (B) no natural selection (C) random mating (D) all of the above,D,"Sometimes understanding how common a gene is within a population is necessary. Or, more specifically, you may want to know how common a certain form of that gene is within the population, such as a recessive form. This can be done using the Hardy-Weinberg model, but it can only be done if the frequencies of the genes are not changing. The Hardy-Weinberg model describes how a population can remain at genetic equilibrium, referred to as the Hardy-Weinberg equilibrium. Genetic equilibrium occurs when there is no evolution within the population. In other words, the frequency of alleles (variants of a gene) will be the same from one generation to another. At genetic equilibrium, the gene or allele frequencies are stablethey do not change. For example, lets assume that red hair is determined by the inheritance of a gene with two allelesR and r. The dominant allele, R, encodes for non-red hair, while the recessive allele, r, encodes for red hair. If a populations gene pool contains 90% R and 10% r alleles, then the next generation would also have 90% R and 10% r alleles. However, this only works under a strict set of conditions. The five conditions that must be met for genetic equilibrium to occur include: 1. 2. 3. 4. 5. No mutation (change) in the DNA sequence. No migration (moving into or out of a population). A very large population size. Random mating. No natural selection. These five conditions rarely occur in nature. When one or more of the conditions does not exist, then evolution can occur. As a result, allele frequencies are constantly changing, and populations are constantly evolving. As mutations and natural selection occur frequently in nature, it is difficult for a population to be at genetic equilibrium. The Hardy-Weinberg model also serves a mathematical formula used to predict allele frequencies in a population at genetic equilibrium. If you know the allele frequencies of one generation, you can use this formula to predict the next generation. Again, this only works if all five conditions are being met in a population. "
which of the following processes selects for specific alleles?,(A) natural selection (B) random mating (C) large population (D) migration,A,"There are four major forces of evolution that cause allele frequencies to change. They are mutation, gene flow, genetic drift, and natural selection. Mutation creates new genetic variation in a gene pool This is how all new alleles first arise. Its the ultimate source of new genetic variation, so it is essential for evolution. However, for any given gene, the chance of a mutation occurring is very small. Therefore, mutation alone does not have much effect on allele frequencies. Gene flow is the movement of genes into or out of a gene pool It occurs when individuals migrate into or out of the population. How much gene flow changes allele frequencies depends on how many migrants there are and their genotypes. Genetic drift is a random change in allele frequencies. It occurs in small populations. Allele frequencies in the offspring may differ by chance from those in the parents. This is like tossing a coin just a few times. You may, by chance, get more or less than the expected 50 percent heads or tails. In the same way, you may get more or less than the expected allele frequencies in the small number of individuals in the next generation. The smaller the population is, the more allele frequencies may drift. Natural selection is a change in allele frequencies that occurs because some genotypes are more fit than others. Genotypes with greater fitness produce more offspring and pass more copies of their alleles to the next generation. This is the force of evolution that Darwin identified. Figure 23.12 shows how Darwin thought natural selection led to variation in finches on the Galpagos Islands. "
"the movement of 100 individuals into an area each winter, and the movement of 50 out of the area each spring is an example of",(A) natural selection (B) random mating (C) migration (D) mutation,C,"Migration is the movement of individual organisms into, or out of, a population. Migration affects population growth rate. There are two types of migration: 1. Immigration is the movement of individuals into a population from other areas. This increases the population size and growth rate. 2. Emigration is the movement of individuals out of a population. This decreases the population size and growth rate. The earlier growth rate equation can be modified to account for migration: growth rate = (birth rate + immigration rate) (death rate + emigration rate). One type of migration that you are probably familiar with is the migration of birds. Maybe you have heard that birds fly south for the winter. In the fall, birds fly thousands of miles to the south where it is warmer. In the spring, they return to their homes. ( Figure 1.2). Monarch butterflies also migrate from Mexico to the northern U.S. in the summer and back to Mexico in the winter. These types of migrations move entire populations from one location to another. A flock of barnacle geese fly in formation during the autumn migration. "
"if a population at genetic equilibrium consists of 75% a alleles one generation, how many a alleles will be in the population the next generation.",(A) 75% (B) 50% (C) 25% (D) 0%,C,"Sometimes understanding how common a gene is within a population is necessary. Or, more specifically, you may want to know how common a certain form of that gene is within the population, such as a recessive form. This can be done using the Hardy-Weinberg model, but it can only be done if the frequencies of the genes are not changing. The Hardy-Weinberg model describes how a population can remain at genetic equilibrium, referred to as the Hardy-Weinberg equilibrium. Genetic equilibrium occurs when there is no evolution within the population. In other words, the frequency of alleles (variants of a gene) will be the same from one generation to another. At genetic equilibrium, the gene or allele frequencies are stablethey do not change. For example, lets assume that red hair is determined by the inheritance of a gene with two allelesR and r. The dominant allele, R, encodes for non-red hair, while the recessive allele, r, encodes for red hair. If a populations gene pool contains 90% R and 10% r alleles, then the next generation would also have 90% R and 10% r alleles. However, this only works under a strict set of conditions. The five conditions that must be met for genetic equilibrium to occur include: 1. 2. 3. 4. 5. No mutation (change) in the DNA sequence. No migration (moving into or out of a population). A very large population size. Random mating. No natural selection. These five conditions rarely occur in nature. When one or more of the conditions does not exist, then evolution can occur. As a result, allele frequencies are constantly changing, and populations are constantly evolving. As mutations and natural selection occur frequently in nature, it is difficult for a population to be at genetic equilibrium. The Hardy-Weinberg model also serves a mathematical formula used to predict allele frequencies in a population at genetic equilibrium. If you know the allele frequencies of one generation, you can use this formula to predict the next generation. Again, this only works if all five conditions are being met in a population. "
"if a population consists of 10% recessive aa phenotype, what amount of the population has the dominant phenotype?",(A) 10% AA (B) 80% Aa (C) 90% (D) all of the above,C,"Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa, for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the populations gene pool. The gene pool is the complete set of genes and alleles within a population. For example, Tay-Sachs disease is a recessive human genetic disorder. That means only individuals with the homozygous recessive genotype, rr will be affected. Affected individuals usually die from complications of the disease in early childhood, at an age too young to reproduce. The two parents are each heterozygous (Rr) for the Tay-Sachs gene; they will not die in childhood and will be carriers of the disease gene. This deadly allele is kept in the gene pool even though it does not help humans adapt to their environment. This happens because evolution acts on the phenotype, not the genotype ( Figure 1.1). Tay-Sachs disease is inherited in the au- tosomal recessive pattern. Each parent is an unaffected carrier of the lethal allele. "
bacteria can be used as a weapon.,(A) true (B) false,A,"Some bacteria also have the potential to be used as biological weapons by terrorists. An example is anthrax, a disease caused by the bacterium Bacillus anthracis. Inhaling the spores of this bacterium can lead to a deadly infection, and, therefore, it is a dangerous weapon. In 2001, an act of terrorism in the United States involved B. anthracis spores sent in letters through the mail. "
"bacteria are so small, and there are so many, that they cannot be killed.",(A) true (B) false,B,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
which diseases are caused by bacteria?,(A) strep throat (B) pneumonia (C) leprosy (D) all of the above,D,"You have ten times as many bacterial cells as human cells in your body. Luckily for you, most of these bacteria are harmless. However, some of them can cause disease. Any organism that causes disease is called a pathogen. Diseases caused by bacterial pathogens include food poisoning, strep throat, and Lyme disease. Bacteria that cause disease may spread directly from person to person. For example, they may spread when people shake hands with, or sneeze on, other people. Bacteria may also spread through food, water, or objects that have become contaminated with them. Some bacteria are spread by vectors. A vector is an organism that spreads bacteria or other pathogens. Most vectors are animals, commonly insects. For example, deer ticks like the one in Figure 8.13 spread Lyme disease. Ticks carry Lyme disease bacteria from deer to people when they bite them. "
lyme disease can be treated with,(A) antibiotics (B) aspirin (C) advil (D) anti-lyme,A,"There are also ways that bacteria can be harmful to humans and other animals. Bacteria are responsible for many types of human illness ( Figure 1.1), including: Strep throat Tuberculosis Pneumonia Leprosy Lyme disease Luckily most of these can be treated with antibiotics, which kill the bacteria. It is important that when a medical doctor prescribes antibiotics for you, you take the medicine exactly as the doctor tells you. You need to make sure the bacteria is killed. "
what foods may cause food poisoning?,(A) scrambled eggs and raw meat (B) raw eggs and undercooked meat (C) raw meat and spoiled eggs (D) steak and eggs,B,"Food poisoning is the common term for foodborne illness. This type of illness occurs when harmful bacteria enter your digestive system in food and make you sick. The bacteriaor toxins they producemay cause cramping, vomiting, or other GI tract symptoms. Following these healthy practices may decrease your risk of foodborne illness: Wash your hands after handling raw foods such as meats, poultry, fish, or eggs. These foods often contain bacteria that your hands could transfer to your mouth. Cook meats, poultry, fish, or eggs thoroughly before eating them. The heat of cooking kills any bacteria the foods may contain so they cant make you sick. Keep hot foods hot and cold foods cold. This is especially important when food is packed for lunch or a picnic (see Figure 17.15). Maintaining the proper temperature slows the growth of bacteria in the food. "
which of the following is an example of a biological weapon?,(A) anthrax (B) anathrax (C) antibiothrax (D) anaphase,A,"Some bacteria also have the potential to be used as biological weapons by terrorists. An example is anthrax, a disease caused by the bacterium Bacillus anthracis. Inhaling the spores of this bacterium can lead to a deadly infection, and, therefore, it is a dangerous weapon. In 2001, an act of terrorism in the United States involved B. anthracis spores sent in letters through the mail. "
what part of a bacterium can be deadly?,(A) the cell wall (B) the cytoplasm (C) the spores (D) the nucleus,C,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
over two million people die each year from issues related to air pollution.,(A) true (B) false,A,Human health suffers in locations with high levels of air pollution. 
"by using some precautions, indoor air pollution can usually be controlled.",(A) true (B) false,A,"You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. "
air pollution related respiratory disorders include,(A) asthma (B) bronchitis (C) and emphysema (D) b asthma (E) bronchitis (F) and lung cancer (G) c heart disease and lung cancer (H) d all of the above,A,"The World Health Organization (WHO) reports that 2.4 million people die each year from causes directly related to air pollution. This includes both outdoor and indoor air pollution. Worldwide, there are more deaths linked to air pollution each year than to car accidents. Research by the WHO also shows that the worst air quality is in countries with high poverty and population rates, such as Egypt, Sudan, Mongolia, and Indonesia. Respiratory system disorders are directly related to air pollution. These disorders have severe effects on human health, some leading to death directly related to air pollution. Air pollution related respiratory disorders include asthma, bronchitis, and emphysema. Asthma is a respiratory disorder characterized by wheezing, coughing, and a feeling of constriction in the chest. Bronchitis is inflammation of the membrane lining of the bronchial tubes of the lungs. Emphysema is a deadly lung disease characterized by abnormal enlargement of air spaces in the lungs and destruction of the lung tissue. Additional lung and heart diseases are also related to air pollution, as are respiratory allergies. Air pollution can also indirectly cause other health issues and even deaths. Air pollutants can cause an increase in cancer including lung cancer, eye problems, and other conditions. For example, using certain chemicals on farms, such as the insecticide DDT (dichlorodiphenyltrichloroethane) and toxic PCBs (polychlorinated biphenyl), can cause cancer. Indoors, pollutants such as radon or asbestos can also increase your cancer risk. Lastly, air pollution can lead to heart disease, including heart attack and stroke. "
which of the following is a method to protect yourself from indoor air pollution?,(A) Keep your home clean from mold (B) Never burn charcoal indoors (C) Place carbon monoxide detectors in the home (D) all of the above,D,"After reading about the effects of air pollution, both indoors and outdoors, you may wonder how you can avoid it. As for outdoor air pollution, if you hear in the news that the outdoor air quality is particularly bad, then it might make sense to wear a mask outdoors or to stay indoors. Because you have more control over your indoor air quality than the outdoor air quality, there are some simple steps you can take indoors to make sure the air quality is less polluted. These include: 1. 2. 3. 4. Make sure that vents and chimneys are working properly, and never burn charcoal indoors. Place carbon monoxide detectors in the home. Keep your home as clean as possible from pet dander, dust, dust mites, and mold. Make sure air conditioning systems are working properly. Are there any other ways you can think of to protect yourself from air pollution? "
which of the following is a method to protect yourself from outdoor air pollution?,(A) wear a mask indoors (B) don’t go outside (C) don’t use charcoal for cooking outdoors (D) all of the above,B,"After reading about the effects of air pollution, both indoors and outdoors, you may wonder how you can avoid it. As for outdoor air pollution, if you hear in the news that the outdoor air quality is particularly bad, then it might make sense to wear a mask outdoors or to stay indoors. Because you have more control over your indoor air quality than the outdoor air quality, there are some simple steps you can take indoors to make sure the air quality is less polluted. These include: 1. 2. 3. 4. Make sure that vents and chimneys are working properly, and never burn charcoal indoors. Place carbon monoxide detectors in the home. Keep your home as clean as possible from pet dander, dust, dust mites, and mold. Make sure air conditioning systems are working properly. Are there any other ways you can think of to protect yourself from air pollution? "
"which of the following is characterized by wheezing, coughing, and a feeling of constriction in the chest?",(A) lung cancer (B) asthma (C) emphysema (D) the flu,B,"Asthma is a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become inflamed and narrow ( Figure 1.2). The muscles around the bronchioles contract, which narrows the airways. Large amounts of mucus are also made by the cells in the lungs. People with asthma have difficulty breathing. Their chests feel tight, and they wheeze. Asthma can be caused by different things, such as allergies. Asthma can also be caused by cold air, warm air, moist air, exercise, or stress. The most common asthma triggers are illnesses, like the common cold. Asthma is not contagious and cannot be passed on to other people. Children and adolescents who have asthma can still lead active lives if they control their asthma. Asthma can be controlled by taking medication and by avoiding contact with environmental triggers for asthma, like smoking. "
"worldwide, there are more deaths linked to air pollution each year than to __________.",(A) heart disease (B) cancer (C) car accidents (D) all of the above,C,"The World Health Organization (WHO) reports that 2.4 million people die each year from causes directly related to air pollution. This includes both outdoor and indoor air pollution. Worldwide, there are more deaths linked to air pollution each year than to car accidents. Research by the WHO also shows that the worst air quality is in countries with high poverty and population rates, such as Egypt, Sudan, Mongolia, and Indonesia. Respiratory system disorders are directly related to air pollution. These disorders have severe effects on human health, some leading to death directly related to air pollution. Air pollution related respiratory disorders include asthma, bronchitis, and emphysema. Asthma is a respiratory disorder characterized by wheezing, coughing, and a feeling of constriction in the chest. Bronchitis is inflammation of the membrane lining of the bronchial tubes of the lungs. Emphysema is a deadly lung disease characterized by abnormal enlargement of air spaces in the lungs and destruction of the lung tissue. Additional lung and heart diseases are also related to air pollution, as are respiratory allergies. Air pollution can also indirectly cause other health issues and even deaths. Air pollutants can cause an increase in cancer including lung cancer, eye problems, and other conditions. For example, using certain chemicals on farms, such as the insecticide DDT (dichlorodiphenyltrichloroethane) and toxic PCBs (polychlorinated biphenyl), can cause cancer. Indoors, pollutants such as radon or asbestos can also increase your cancer risk. Lastly, air pollution can lead to heart disease, including heart attack and stroke. "
lots of people are allergic to shellfish.,(A) true (B) false,A,"Food allergies occur when the immune system reacts to harmless substances in food as though they were harmful germs. Food allergies are relatively common. Almost 10 percent of children have them. Some of the foods most likely to cause allergies include milk, shellfish, nuts, grains, and eggs. If you eat foods to which you are allergic, you may experience vomiting, diarrhea, or a rash. In some people, eating even tiny amounts of certain foods causes them to have serious symptoms, such as difficulty breathing. They need immediate medical attention. The best way to prevent food allergy symptoms is to avoid eating the offending food. This may require careful reading of food labels. "
well over 10% of the worlds population has problems digesting milk.,(A) true (B) false,A,"A food intolerance, or food sensitivity, is different from a food allergy. A food intolerance happens when the digestive system is unable to break down a certain type of food. This can result in stomach cramping, diarrhea, tiredness, and weight loss. Food intolerances are often mistakenly called allergies. Lactose intolerance is a food intolerance. A person who is lactose intolerant does not make enough lactase, the enzyme that breaks down the milk sugar, lactose. Lactose intolerance may be as high as 75% in some populations, but overall the percentage of affected individuals is much less. Still, well over 10% of the worlds population is lactose intolerant. "
which are common foods that cause food allergies?,(A) milk (B) nuts and apples (C) b nuts (D) steak and eggs (E) c milk (F) shellfish and bananas (G) d grains (H) eggs and nuts,D,"Food allergies occur when the immune system reacts to harmless substances in food as though they were harmful germs. Food allergies are relatively common. Almost 10 percent of children have them. Some of the foods most likely to cause allergies include milk, shellfish, nuts, grains, and eggs. If you eat foods to which you are allergic, you may experience vomiting, diarrhea, or a rash. In some people, eating even tiny amounts of certain foods causes them to have serious symptoms, such as difficulty breathing. They need immediate medical attention. The best way to prevent food allergy symptoms is to avoid eating the offending food. This may require careful reading of food labels. "
methods to prevent foodborne illnesses include,(A) cooking meats (B) poultry (C) fish (D) and eggs thoroughly (E) b keeping cold foods hot and hot foods cold (F) c the refrigeration of uncooked foods soon after a meal (G) d all of the above,A,"Bacterial contamination of foods can lead to digestive problems, an illness known as food poisoning. Raw eggs and undercooked meats commonly carry the bacteria that can cause food poisoning. Food poisoning can be prevented by cooking meat thoroughly, which kills most microbes, and washing surfaces that have been in contact with raw meat. Washing your hands before and after handling food also helps prevent contamination. "
which virus has caused foodborne illnesses on cruise ships?,(A) hepatitis A virus (B) norovirus (C) Listeria (D) Salmonella,B,"Harmful bacteria can enter your digestive system in food and make you sick. This is called foodborne illness or food poisoning. The bacteria, or the toxins they produce, may cause vomiting or cramping, in addition to the symptoms mentioned above. Foodborne illnesses can also be caused by viruses and parasites. The most common foodborne illnesses happen within a few minutes to a few hours, and make you feel really sick, but last for only about a day or so. Others can take longer for the illness to appear. Some people believe that the taste of food will tell you if it is bad. As a rule, you probably should not eat bad tasting food, but many contaminated foods can still taste good. You can help prevent foodborne illness by following a few simple rules. Keep hot foods hot and cold foods cold. This helps prevent any bacteria in the foods from multiplying. Wash your hands before you prepare or eat food. This helps prevent bacteria on your hands from getting on the food. This is the easiest way to prevent foodborne illnesses. Wash your hands after you touch raw foods, such as meats, poultry, fish, or eggs. These foods often contain bacteria that your hands could transfer to your mouth. Cook meats, poultry, fish, and eggs thoroughly before eating them. The heat of cooking kills any bacteria the foods may contain, so they cannot make you sick. Refrigerate cooked food soon after a meal. Cooked food can be left out for up to two hours before they need to be placed in the cold. This will prevent the spread of bacteria. Cooked foods should not be left out all day. Bacteria that cause foodborne illnesses include Salmonella, a bacterium found in many foods, including raw and undercooked meat, poultry, dairy products, and seafood. Campylobacter jejuni is found in raw or undercooked chicken and unpasteurized milk. Several strains of E. coli can cause illnesses, and are found in raw or undercooked hamburger, unpasteurized fruit juices and milk, and even fresh produce. Vibrio is a bacterium that may contaminate fish or shellfish. Listeria has been found in raw and undercooked meats, unpasteurized milk, soft cheeses, and ready- to-eat deli meats and hot dogs. Most of these bacterial illnesses can be prevented with proper cooking of food and washing of hands. Common foodborne viruses include norovirus and hepatitis A virus. Norovirus, which causes inflammation of the stomach and intestines, has been a recent issue on cruise ships, infecting hundreds of passengers and crew on certain voyages. Hepatitis A causes inflammation of the liver, which is treated with rest and diet changes. Parasites are tiny organisms that live inside another organism. Giardia is a parasite spread through water contaminated with the stools of people or animals who are infected. Food preparers who are infected with parasites can also contaminate food if they do not thoroughly wash their hands after using the bathroom and before handling food. Trichinella is a type of roundworm parasite. People may be infected with this parasite by consuming raw or undercooked pork or wild game. "
symptoms of anaphylaxis include,(A) a swollen throat (B) a rapid pulse (C) loss of consciousness (D) all of the above,D,"Food allergies are like other allergies. They occur when the immune system reacts to harmless substances as though they were harmful. Almost ten percent of children have food allergies. Some of the foods most likely to cause allergies are shown below ( Figure 1.1). Eating foods you are allergic to may cause vomiting, diarrhea, or skin rashes. Some people are very allergic to certain foods. Eating even tiny amounts of the foods causes them to have serious symptoms, such as difficulty breathing. If they eat the foods by accident, they may need emergency medical treatment. Some of the foods that commonly cause allergies are shown here. They include nuts, eggs, grains, milk, and shellfish. Are you allergic to any of these foods? The most common food allergy symptoms include: tingling or itching in the mouth hives, itching or eczema, swelling of the lips, face, tongue and throat, or other parts of the body, wheezing, nasal congestion or trouble breathing, abdominal pain, diarrhea, nausea or vomiting, dizziness, lightheadedness or fainting. In some people, a food allergy can trigger a severe allergic reaction called anaphylaxis. Emergency treatment is critical for anaphylaxis. Untreated, anaphylaxis can cause a coma or death. Anaphylaxis is vary rare. The vast majority of people will never have an anaphylactic reaction. The life-threatening symptoms of anaphylaxis include: constriction and tightening of the airway, a swollen throat or the sensation of a lump in your throat that makes it difficult to breathe, shock, with a severe drop in blood pressure, a rapid pulse, dizziness, lightheadedness or loss of consciousness. "
common food allergies include,(A) tingling or itching of the stomach (B) swelling of the lips (C) face (D) tongue and throat (E) c a severe drop in blood pressure (F) d all of the above,B,"Food allergies occur when the immune system reacts to harmless substances in food as though they were harmful germs. Food allergies are relatively common. Almost 10 percent of children have them. Some of the foods most likely to cause allergies include milk, shellfish, nuts, grains, and eggs. If you eat foods to which you are allergic, you may experience vomiting, diarrhea, or a rash. In some people, eating even tiny amounts of certain foods causes them to have serious symptoms, such as difficulty breathing. They need immediate medical attention. The best way to prevent food allergy symptoms is to avoid eating the offending food. This may require careful reading of food labels. "
hearing is the ability to sense sound.,(A) true (B) false,A,"The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. "
our ears interpret the sounds that we hear.,(A) true (B) false,B,"The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. "
what part of the ear is involved in maintaining balance?,(A) the tympanic cavity (B) the cochlear nerve (C) the semicircular canals (D) all of the above,C,"Did you ever try to stand on one foot with your eyes closed? Try it and see what happens, but be careful! Its harder to keep your balance when you cant see. Your eyes obviously play a role in balance. But your ears play an even bigger role. The gymnast pictured below ( Figure 1.3) may not realize it, but her earsalong with her cerebellumare mostly responsible for her ability to perform on the balance beam. The parts of the ears involved in balance are the semicircular canals. Above, the semicircular canals are colored purple ( Figure 1.2). The canals contain liquid and are like the bottle of water pictured below ( Figure 1.4). When the bottle tips, the water surface moves up and down the sides of the bottle. When the body tips, the liquid in the semicircular canals moves up and down the sides of the canals. Tiny hair cells line the semicircular canals. Movement of the liquid inside the canals causes the hair cells to send nerve impulses. The nerve impulses travel to the cerebellum in the brain along the vestibular nerve. In response, the cerebellum sends commands to muscles to contract or relax so that the body stays balanced. "
"once sound waves enter the ear, vibrations pass from the eardrum to the",(A) hammer (B) anvil (C) stirrup (D) oval window,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
what part of the ear is lined with tiny hairs and filled with fluid?,(A) the auditory canal (B) the Eustachian tube (C) the cochlea (D) the tympanic cavity,C,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
what part of the ear passes vibrations to the cochlea of the inner ear?,(A) the oval window (B) the round window (C) the cochlear canal (D) the stapes,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
how is the signal relayed to the brain to tell the body to maintain balance?,(A) The signal is sent through the cochlear nerve (B) The signal is sent through the vestibular nerve (C) The signal is sent through the Eustachian tube (D) The signal is sent through the semicircular canals,B,"Michelle was riding her scooter when she hit a hole in the street and started to lose control. She thought she would fall, but, in the blink of an eye, she shifted her weight and kept her balance. Her heart was pounding, but at least she didnt get hurt. How was she able to react so quickly? Michelle can thank her nervous system for that ( Figure 1.1). The nervous system, together with the endocrine system, controls all the other organ systems. The nervous system sends one type of signal around the body, and the endocrine system sends another type of signal around the body. The endocrine system makes and releases chemical messenger molecules, or hormones, which tell other body parts that a change or a reaction is necessary. So what type of signal does the nervous system send? Controlling muscles and maintaining balance are just two of the roles of the nervous system. The nervous system also lets you: Sense your surroundings with your eyes and other sense organs. Sense the environment inside of your body, including temperature. Control your internal body systems and keep them in balance. Staying balanced when riding a scooter requires control over the bodys muscles. The nervous system controls the muscles and maintains balance. Prepare your body to fight or flee in an emergency. Use language, think, learn, and remember. The nervous system works by sending and receiving electrical signals. The main organs of the nervous system are the brain and the spinal cord. The signals are carried by nerves in the body, similar to the wires that carry electricity all over a house. The signals travel from all over the body to the spinal cord and up to the brain, as well as moving in the other direction. For example, when Michelle started to fall off her scooter, her nervous system sensed that she was losing her balance. It responded by sending messages from her brain to muscles in her body. Some muscles tightened while others relaxed. Maybe these actions moved her hips or her arms. The nervous system, working together with the muscular and skeletal systems, allowed Michelle to react to the situation. As a result, Michelles body became balanced again. The messages released by the nervous system traveled through nerves. Just like the electricity that travels through wires, nerve quickly carry the electrical messages around the body. Think about how quickly all this happens. It has to be really fast, otherwise Michelle would not have been able to react. What would happen if a car pulled out unexpectedly in front of Michelle? A signal would have to go from her eyes to her brain and then to her muscles. What allows the nervous system to react so fast. It starts with the special cell of the nervous system, the neuron. "
the ventricles are more muscular than the atria.,(A) true (B) false,A,"What does the heart look like? How does it pump blood? The heart is divided into four chambers ( Figure 1.1), or spaces: the left and right atria, and the left and right ventricles. An atrium (singular for atria) is one of the two small, thin-walled chambers on the top of the heart where the blood first enters. A ventricle is one of the two muscular V-shaped chambers that pump blood out of the heart. You can remember they are called ventricles because they are shaped like a ""V."" The atria receive the blood, and the ventricles pump the blood out of the heart. Each of the four chambers of the heart has a specific job. The right atrium receives oxygen-poor blood from the body. The right ventricle pumps oxygen-poor blood toward the lungs, where it receives oxygen. The left atrium receives oxygen-rich blood from the lungs. The left ventricle pumps oxygen-rich blood out of the heart to the rest of the body. "
valves in the heart keep the blood flowing in one direction.,(A) true (B) false,A,"Blood flows through the heart in two separate loops. You can think of them as a left side loop and a right side loop. The right side of the heart collects oxygen-poor blood from the body and pumps it into the lungs, where it releases carbon dioxide and picks up oxygen. (Recall that carbon dioxide is a waste product that must be removed. It is removed when we exhale.) The left side carries the oxygen-rich blood back from the lungs into the left side of the heart, which then pumps the oxygen-rich blood to the rest of the body. The blood delivers oxygen to the cells of the body, where it is needed for cellular respiration, and returns to the heart oxygen-poor. To move blood through the heart, the cardiac muscle needs to contract in an organized way. Blood first enters the atria ( Figure 1.2). When the atria contract, blood is pushed into the ventricles. After the ventricles fill with blood, they contract, and blood is pushed out of the heart. The heart is mainly composed of cardiac muscle. These muscle cells contract in unison, causing the heart itself to contract and generating enough force to push the blood out. So how is the blood kept from flowing back on itself? Valves ( Figure 1.2) in the heart keep the blood flowing in one direction. The valves do this by opening and closing in one direction only. Blood only moves forward through the heart. The valves stop the blood from flowing backward. There are four valves of the heart. The two atrioventricular (AV) valves stop blood from moving from the ventricles to the atria. The two semilunar (SL) valves are found in the arteries leaving the heart, and they prevent blood from flowing back from the arteries into the ventricles. Why does a heart beat? The lub-dub sound of the heartbeat is caused by the closing of the AV valves (""lub"") and SL valves (""dub"") after blood has passed through them. "
what is the role of the semilunar valves?,(A) To stop blood from moving from the arteries into the ventricles (B) To stop blood from moving from the ventricles to the atria (C) To stop blood from moving from the atria to the ventricles (D) To stop blood from moving from the artria to the veins,A,"Blood flows through the heart in two separate loops. You can think of them as a left side loop and a right side loop. The right side of the heart collects oxygen-poor blood from the body and pumps it into the lungs, where it releases carbon dioxide and picks up oxygen. (Recall that carbon dioxide is a waste product that must be removed. It is removed when we exhale.) The left side carries the oxygen-rich blood back from the lungs into the left side of the heart, which then pumps the oxygen-rich blood to the rest of the body. The blood delivers oxygen to the cells of the body, where it is needed for cellular respiration, and returns to the heart oxygen-poor. To move blood through the heart, the cardiac muscle needs to contract in an organized way. Blood first enters the atria ( Figure 1.2). When the atria contract, blood is pushed into the ventricles. After the ventricles fill with blood, they contract, and blood is pushed out of the heart. The heart is mainly composed of cardiac muscle. These muscle cells contract in unison, causing the heart itself to contract and generating enough force to push the blood out. So how is the blood kept from flowing back on itself? Valves ( Figure 1.2) in the heart keep the blood flowing in one direction. The valves do this by opening and closing in one direction only. Blood only moves forward through the heart. The valves stop the blood from flowing backward. There are four valves of the heart. The two atrioventricular (AV) valves stop blood from moving from the ventricles to the atria. The two semilunar (SL) valves are found in the arteries leaving the heart, and they prevent blood from flowing back from the arteries into the ventricles. Why does a heart beat? The lub-dub sound of the heartbeat is caused by the closing of the AV valves (""lub"") and SL valves (""dub"") after blood has passed through them. "
what happens to the blood in the lungs?,(A) Oxygen-poor blood releases oxygen and picks up carbon dioxide (B) Oxygen-poor blood releases carbon dioxide and picks up oxygen (C) Oxygen-rich blood releases oxygen and picks up carbon dioxide (D) Oxygen-rich blood releases carbon dioxide and picks up oxygen,B,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
what part of the heart receives oxygen-poor blood from the body?,(A) The left ventricle receives oxygen-poor blood from the body (B) The left atrium receives oxygen-poor blood from the body (C) The right atrium receives oxygen-poor blood from the body (D) The right ventricle receives oxygen-poor blood from the body,C,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
what do you think would happen if a heart had a leaky av valve?,(A) Blood would flow back from the ventricles to the atria (B) Blood would flow back from the atria to the ventricles (C) Blood would flow back from the veins to the atria (D) Blood would flow back from the arteries to the ventricles,A,"Blood flows through the heart in two separate loops. You can think of them as a left side loop and a right side loop. The right side of the heart collects oxygen-poor blood from the body and pumps it into the lungs, where it releases carbon dioxide and picks up oxygen. (Recall that carbon dioxide is a waste product that must be removed. It is removed when we exhale.) The left side carries the oxygen-rich blood back from the lungs into the left side of the heart, which then pumps the oxygen-rich blood to the rest of the body. The blood delivers oxygen to the cells of the body, where it is needed for cellular respiration, and returns to the heart oxygen-poor. To move blood through the heart, the cardiac muscle needs to contract in an organized way. Blood first enters the atria ( Figure 1.2). When the atria contract, blood is pushed into the ventricles. After the ventricles fill with blood, they contract, and blood is pushed out of the heart. The heart is mainly composed of cardiac muscle. These muscle cells contract in unison, causing the heart itself to contract and generating enough force to push the blood out. So how is the blood kept from flowing back on itself? Valves ( Figure 1.2) in the heart keep the blood flowing in one direction. The valves do this by opening and closing in one direction only. Blood only moves forward through the heart. The valves stop the blood from flowing backward. There are four valves of the heart. The two atrioventricular (AV) valves stop blood from moving from the ventricles to the atria. The two semilunar (SL) valves are found in the arteries leaving the heart, and they prevent blood from flowing back from the arteries into the ventricles. Why does a heart beat? The lub-dub sound of the heartbeat is caused by the closing of the AV valves (""lub"") and SL valves (""dub"") after blood has passed through them. "
what do you think would happen if muscle cells contracted independently?,(A) Only some of the blood would be pushed out (B) Blood would flow backwards into the heart (C) There would not be enough force to push the blood out (D) All of the above would be consequences,C,"The muscular system consists of all the muscles in the body. This is the body system that allows us to move. You also depend on many muscles to keep you alive. Your heart, which is mostly muscle, pumps blood around your body. Each muscle in the body is made up of cells called muscle fibers. Muscle fibers are long, thin cells that can do something that other cells cannot dothey are able to get shorter. Shortening of muscle fibers is called contraction. Muscle fibers can contract because they are made of proteins, called actin and myosin, that form long filaments (or fibers). When muscles contract, these protein filaments slide or glide past one another, shortening the length of the cell. When your muscles relax, the length extends back to the previous position. Nearly all movement in the body is the result of muscle contraction. You can control some muscle movements. However, certain muscle movements happen without you thinking about them. Muscles that are under your conscious control are called voluntary muscles. Muscles that are not under your conscious control are called involuntary muscles. Muscle tissue is one of the four types of tissue found in animals. There are three different types of muscle in the body ( Figure 1.1): 1. Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. 2. Smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. These muscles push materials like food or blood through organs. Unlike skeletal muscle, smooth muscle can never be under your control. 3. Cardiac muscle is also an involuntary muscle, found only in the heart. The cardiac muscle fibers all contract together, generating enough force to push blood throughout the body. What would happen if this muscle was under conscious or voluntary control? There are three types of muscles in the body: cardiac, skeletal, and smooth. "
we need bacteria to survive.,(A) true (B) false,A,"Can we survive without bacteria? Could bacteria survive without us? No and yes. No, we could not survive without bacteria. And yes, bacteria could survive without us. "
"in your gut, bacteria cells outnumber your own cells.",(A) true (B) false,A,"Bacteria also help you digest your food. Several species of bacteria, such as E. coli, are found in your digestive tract. In fact, in your gut, bacteria cells greatly outnumber your own cells! "
"during fermentation, bacteria turn milk sugars into",(A) carbon dioxide (B) oxygen (C) lactic acid (D) glucose,C,"Bacteria can be used to make cheese from milk. The bacteria turn the milk sugars into lactic acid. The acid is what causes the milk to curdle to form cheese. Bacteria are also involved in producing other foods. Yogurt is made by using bacteria to ferment milk ( Figure 1.1). Fermenting cabbage with bacteria produces sauerkraut. Yogurt is made from milk fermented with bacteria. The bacteria ingest natural milk sugars and release lactic acid as a waste product, which causes proteins in the milk to form into a solid mass, which becomes the yogurt. "
bacteria have been used to produce human versions of,(A) lactic acid (B) insulin (C) nitrogen (D) yogurt,B,"In the laboratory, bacteria can be changed to provide us with a variety of useful materials. Bacteria can be used as tiny factories to produce desired chemicals and medicines. For example, insulin, which is necessary to treat people with diabetes, can be produced using bacteria. Through the process of transformation, the human gene for insulin is placed into bacteria. The bacteria then use that gene to make a protein. The protein can be separated from the bacteria and then used to treat patients. The mass production of insulin by bacteria made this medicine much more affordable. During transformation, bacteria can take up any DNA from the environment. Therefore, transformation allows scientists to insert any DNA into a bacteria, potentially producing many different proteins. This makes the bacteria greatly useful to people. "
"fermentation occurs in the absence of oxygen. fermentation allows glycolysis, the first step of cellular respiration, to continue, producing 2 atp in the process. lactic acid is produced in certain types of fermentation. what is the waste product in this process?",(A) glucose (B) lactic acid (C) oxygen (D) ATP,B,"Sometimes cells need to obtain energy from sugar, but there is no oxygen present to complete cellular respiration. In this situation, cellular respiration can be anaerobic, occurring in the absence of oxygen. In this process, called fermentation, only the first step of respiration, glycolysis, occurs, producing two ATP; no additional ATP is produced. Therefore, the organism only obtains the two ATP molecules per glucose molecule from glycolysis. Compared to the 36-38 ATP produced under aerobic conditions, anaerobic respiration is not a very efficient process. Fermentation allows the first step of cellular respiration to continue and produce some ATP, even without oxygen. Yeast (single-celled eukaryotic organisms) perform alcoholic fermentation in the absence of oxygen. The products of alcoholic fermentation are ethyl alcohol (drinking alcohol) and carbon dioxide gas. This process is used to make common food and drinks. For example, alcoholic fermentation is used to bake bread. The carbon dioxide bubbles allow the bread to rise and become fluffy. Meanwhile, the alcohol evaporates. In wine making, the sugars of grapes are fermented to produce wine. The sugars are the starting materials for glycolysis. Animals and some bacteria and fungi carry out lactic acid fermentation. Lactic acid is a waste product of this process. Our muscles perform lactic acid fermentation during strenuous exercise, since oxygen cannot be delivered to the muscles quickly enough. The buildup of lactic acid is believed to make your muscles sore after exercise. Bacteria that produce lactic acid are used to make cheese and yogurt. The lactic acid causes the proteins in milk to thicken. Lactic acid also causes tooth decay, because bacteria use the sugars in your mouth for energy. Pictured below are some products of fermentation ( Figure 1.1). Products of fermentation include cheese (lactic acid fermentation) and wine (alco- holic fermentation). "
what process is used when placing a foreign gene into bacteria?,(A) transformation (B) transduction (C) transcription (D) translation,A,"Bacteria have small rings of DNA in the cytoplasm, called plasmids ( Figure 1.1). A plasmid is not part of the bacterial chromosome, but an additional pieced of DNA. When putting foreign DNA into a bacterium, the plasmids are often used as a vector. Viruses can also be used as vectors. The manipulation of the plasmid DNA, and then the insertion of the recombinant plasmid into a bacterium, is an invaluable tool in scientific research. This image shows a drawing of a plasmid. The plasmid has two large segments and one small segment depicted. The two large segments (green and blue) indicate antibiotic resistances usually used in a screening procedure. The antibiotic resis- tance segments ensure only bacteria with the plasmid will grow. The small segment (red) indicates an origin of replication. The origin of replication is where DNA replication starts, copying the plasmid. "
"decomposers help recycle nutrients so organisms can use them. decomposers include scavengers like vultures, as well as many types of worms, fungi and bacteria. what nutrient does bacteria recycle?",(A) vitamin C (B) vitamin D (C) magnesium (D) nitrogen,D,"Bacteria known as decomposers break down wastes and dead organisms into smaller molecules. These bacteria use the organic substrates they break down to get their energy, carbon, and nutrients they need for survival. "
the development of aids can be delayed by well over 20 years with proper medicines.,(A) true (B) false,A,"HIV, or human immunodeficiency virus, causes AIDS. AIDS stands for ""acquired immune deficiency syndrome."" It is a condition that causes death and does not have a known cure. AIDS usually develops 10 to 15 years after a person is first infected with HIV. The development of AIDS can be delayed with proper medicines. The delay can be well over 20 years with the right medicines. Today, individuals who acquire HIV after 50 years of age can expect to reach an average human life span. "
hiv spreads through kissing.,(A) true (B) false,B,"HIV spreads through contact between an infected persons body fluids and another persons bloodstream or mucus membranes, which are found in the mouth, nose, and genital areas. Body fluids that may contain HIV are blood, semen, vaginal fluid, and breast milk. The virus can spread through sexual contact or shared drug needles. It can also spread from an infected mother to her baby during childbirth or breastfeeding. Saliva can carry the HIV virus, but it wont spread it, unless the saliva gets into the bloodstream. Other body fluids such as urine and sweat do not contain the virus. HIV does not spread in any fluid in which the host cells cannot survive. Some people think they can become infected with HIV by donating blood or receiving donated blood. This is not true. The needles used to draw blood for donations are always new. Therefore, they cannot spread the virus. Donated blood is also tested to make sure it is does not contain HIV. HIV is not transmitted by day-to-day contact in the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging, or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a door knob, dishes, drinking glasses, food, or pets. "
why is donated blood safe from hiv?,(A) People with HIV are prevented from donating blood (B) Donated blood is also tested to make sure it is does not contain HIV (C) HIV is removed from all donated blood (D) all of the above,B,"HIV spreads through contact between an infected persons body fluids and another persons bloodstream or mucus membranes, which are found in the mouth, nose, and genital areas. Body fluids that may contain HIV are blood, semen, vaginal fluid, and breast milk. The virus can spread through sexual contact or shared drug needles. It can also spread from an infected mother to her baby during childbirth or breastfeeding. Saliva can carry the HIV virus, but it wont spread it, unless the saliva gets into the bloodstream. Other body fluids such as urine and sweat do not contain the virus. HIV does not spread in any fluid in which the host cells cannot survive. Some people think they can become infected with HIV by donating blood or receiving donated blood. This is not true. The needles used to draw blood for donations are always new. Therefore, they cannot spread the virus. Donated blood is also tested to make sure it is does not contain HIV. HIV is not transmitted by day-to-day contact in the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging, or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a door knob, dishes, drinking glasses, food, or pets. "
"without proper medicines, aids usually develops __________ years after a person is first infected with hiv.",(A) 1 to 5 (B) 5 to 10 (C) 10 to 15 (D) more than 20,C,"HIV, or human immunodeficiency virus, causes AIDS. AIDS stands for ""acquired immune deficiency syndrome."" It is a condition that causes death and does not have a known cure. AIDS usually develops 10 to 15 years after a person is first infected with HIV. The development of AIDS can be delayed with proper medicines. The delay can be well over 20 years with the right medicines. Today, individuals who acquire HIV after 50 years of age can expect to reach an average human life span. "
what continent is the hardest hit by hiv?,(A) North America (B) Asia (C) Africa (D) Australia,C,"AIDS is not really a single disease. It is a set of symptoms and other diseases. It results from years of damage to the immune system by HIV. AIDS occurs when helper T cells fall to a very low level, making it difficult for the affected person to fight various diseases and other infections. These people develop infections or cancers that people with a healthy immune systems can easily resist. These diseases are usually the cause of death of people with AIDS. The first known cases of AIDS occurred in 1981. Since then, AIDS has led to the deaths of more than 35 million people worldwide. Many of them were children. The greatest number of deaths occurred in Africa. It is also where medications to control HIV are least available. There are currently more people infected with HIV in Africa than any other part of the world. Well over 30 million people are living with HIV worldwide. "
what body fluid can spread hiv?,(A) breast milk (B) sweat (C) saliva (D) All body fluids can spread HIV,A,"HIV spreads through contact between an infected persons body fluids and another persons bloodstream or mucus membranes, which are found in the mouth, nose, and genital areas. Body fluids that may contain HIV are blood, semen, vaginal fluid, and breast milk. The virus can spread through sexual contact or shared drug needles. It can also spread from an infected mother to her baby during childbirth or breastfeeding. Saliva can carry the HIV virus, but it wont spread it, unless the saliva gets into the bloodstream. Other body fluids such as urine and sweat do not contain the virus. HIV does not spread in any fluid in which the host cells cannot survive. Some people think they can become infected with HIV by donating blood or receiving donated blood. This is not true. The needles used to draw blood for donations are always new. Therefore, they cannot spread the virus. Donated blood is also tested to make sure it is does not contain HIV. HIV is not transmitted by day-to-day contact in the workplace, schools, or social settings. HIV is not transmitted through shaking hands, hugging, or a casual kiss. You cannot become infected from a toilet seat, a drinking fountain, a door knob, dishes, drinking glasses, food, or pets. "
when does aids develop?,(A) AIDS develops when a person with HIV catches a cold (B) AIDS develops when helper T cells fall to a very low level (C) AIDS develops when a person with HIV produces more virus (D) AIDS develops when the vaccine no longer works in that person,B,"HIV, or human immunodeficiency virus, causes AIDS. AIDS stands for ""acquired immune deficiency syndrome."" It is a condition that causes death and does not have a known cure. AIDS usually develops 10 to 15 years after a person is first infected with HIV. The development of AIDS can be delayed with proper medicines. The delay can be well over 20 years with the right medicines. Today, individuals who acquire HIV after 50 years of age can expect to reach an average human life span. "
your body temperature drops on a cold day.,(A) true (B) false,B,"When you walk outside on a cool day, does your body temperature drop? No, your body temperature stays stable at around 98.6 degrees Fahrenheit. Even when the temperature around you changes, your internal temperature stays the same. This ability of the body to maintain a stable internal environment despite a changing environment is called home- ostasis. Homeostasis doesnt just protect against temperature changes. Other aspects of your internal environment also stay stable. For example, your body closely regulates your fluid balance. You may have noticed that if you are slightly dehydrated, your urine is darker. Thats because the urine is more concentrated and less water is mixed in with it. "
"your body temperature always tries to be around 98.6 degrees fahrenheit, even if it is very hot outside.",(A) true (B) false,A,"When you walk outside on a cool day, does your body temperature drop? No, your body temperature stays stable at around 98.6 degrees Fahrenheit. Even when the temperature around you changes, your internal temperature stays the same. This ability of the body to maintain a stable internal environment despite a changing environment is called home- ostasis. Homeostasis doesnt just protect against temperature changes. Other aspects of your internal environment also stay stable. For example, your body closely regulates your fluid balance. You may have noticed that if you are slightly dehydrated, your urine is darker. Thats because the urine is more concentrated and less water is mixed in with it. "
your bodys internal thermostat is regulated by,(A) negative feedback (B) positive feedback (C) homeostasis (D) receptors in the skin and the brain,A,"So how does your body maintain homeostasis? The regulation of your internal environment is done primarily through negative feedback. Negative feedback is a response to a stimulus that keeps a variable close to a set value ( Figure For example, your body has an internal thermostat. During a winter day, in your house a thermostat senses the temperature in a room and responds by turning on or off the heater. Your body acts in much the same way. When body temperature rises, receptors in the skin and the brain sense the temperature change. The temperature change triggers a command from the brain. This command can cause several responses. If you are too hot, the skin makes sweat and blood vessels near the skin surface dilate. This response helps decrease body temperature. Another example of negative feedback has to do with blood glucose levels. When glucose (sugar) levels in the blood are too high, the pancreas secretes insulin to stimulate the absorption of glucose and the conversion of glucose into glycogen, which is stored in the liver. As blood glucose levels decrease, less insulin is produced. When glucose levels are too low, another hormone called glucagon is produced, which causes the liver to convert glycogen back to glucose. For additional information, see Homeostasis at  . Feedback Regulation. If a raise in body temperature (stimulus) is detected (recep- tor), a signal will cause the brain to main- tain homeostasis (response). Once the body temperature returns to normal, neg- ative feedback will cause the response to end. This sequence of stimulus-receptor- signal-response is used throughout the body to maintain homeostasis. "
which is an example of positive feedback?,(A) maintaining stable blood glucose levels (B) the production of milk in a nursing mother (C) maintaining a stable body temperature (D) all of the above,B,"Some processes in the body are regulated by positive feedback. Positive feedback is when a response to an event increases the likelihood of the event to continue. An example of positive feedback is milk production in nursing mothers. As the baby drinks her mothers milk, the hormone prolactin, a chemical signal, is released. The more the baby suckles, the more prolactin is released, which causes more milk to be produced. Other examples of positive feedback include contractions during childbirth. When constrictions in the uterus push a baby into the birth canal, additional contractions occur. "
which hormone stimulates the removal of sugar from the blood?,(A) glucose (B) glucagon (C) insulin (D) glycogen,C,"The organ systems of the body work together to carry out life processes and maintain homeostasis. The body is in homeostasis when its internal environment is kept more-or-less constant. For example, levels of sugar, carbon dioxide, and water in the blood must be kept within narrow ranges. This requires continuous adjustments. For example: After you eat and digest a sugary snack, the level of sugar in your blood quickly rises. In response, the endocrine system secretes the hormone insulin. Insulin helps cells absorb sugar from the blood. This causes the level of sugar in the blood to fall back to its normal level. When you work out on a hot day, you lose a lot of water through your skin in sweat. The level of water in the blood may fall too low. In response, the excretory system excretes less water in urine. Instead, the water is returned to the blood to keep water levels from falling lower. What happens if homeostasis is not maintained? Cells may not get everything they need, or toxic wastes may build up in the body. If homeostasis is not restored, it may cause illness or even death. "
which is the proper sequence of events in maintaining homeostasis?,(A) signal (B) 2 (C) b stimulus (D) 2 (E) c receptor (F) 2 (G) d stimulus (H) 2,D,"The organ systems of the body work together to carry out life processes and maintain homeostasis. The body is in homeostasis when its internal environment is kept more-or-less constant. For example, levels of sugar, carbon dioxide, and water in the blood must be kept within narrow ranges. This requires continuous adjustments. For example: After you eat and digest a sugary snack, the level of sugar in your blood quickly rises. In response, the endocrine system secretes the hormone insulin. Insulin helps cells absorb sugar from the blood. This causes the level of sugar in the blood to fall back to its normal level. When you work out on a hot day, you lose a lot of water through your skin in sweat. The level of water in the blood may fall too low. In response, the excretory system excretes less water in urine. Instead, the water is returned to the blood to keep water levels from falling lower. What happens if homeostasis is not maintained? Cells may not get everything they need, or toxic wastes may build up in the body. If homeostasis is not restored, it may cause illness or even death. "
which is an example of negative feedback?,(A) maintaining stable blood glucose levels (B) the production of milk in a nursing mother (C) contractions of the uterus during childbirth (D) all of the above,A,"So how does your body maintain homeostasis? The regulation of your internal environment is done primarily through negative feedback. Negative feedback is a response to a stimulus that keeps a variable close to a set value ( Figure For example, your body has an internal thermostat. During a winter day, in your house a thermostat senses the temperature in a room and responds by turning on or off the heater. Your body acts in much the same way. When body temperature rises, receptors in the skin and the brain sense the temperature change. The temperature change triggers a command from the brain. This command can cause several responses. If you are too hot, the skin makes sweat and blood vessels near the skin surface dilate. This response helps decrease body temperature. Another example of negative feedback has to do with blood glucose levels. When glucose (sugar) levels in the blood are too high, the pancreas secretes insulin to stimulate the absorption of glucose and the conversion of glucose into glycogen, which is stored in the liver. As blood glucose levels decrease, less insulin is produced. When glucose levels are too low, another hormone called glucagon is produced, which causes the liver to convert glycogen back to glucose. For additional information, see Homeostasis at  . Feedback Regulation. If a raise in body temperature (stimulus) is detected (recep- tor), a signal will cause the brain to main- tain homeostasis (response). Once the body temperature returns to normal, neg- ative feedback will cause the response to end. This sequence of stimulus-receptor- signal-response is used throughout the body to maintain homeostasis. "
the job of the eye is to focus light.,(A) true (B) false,A,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
light is focused on the lens of the eye.,(A) true (B) false,B,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
what covers the back inside part of the eye?,(A) the cornea (B) the pupil (C) the retina (D) the lens,C,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
what parts focus light on the back of the eye?,(A) the cornea and lens (B) the pupil and lens (C) the cornea and pupil (D) the lens and retina,A,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
what allows us to detect light of different colors?,(A) rod cells (B) cone cells (C) the retina (D) the pupil,B,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
light enters the eye through the __________.,(A) cornea (B) retina (C) pupil (D) lens,C,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
what serves to protect the eye?,(A) the lens (B) the cornea (C) the pupil (D) the retina,B,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
most current species extinction is because of humans.,(A) true (B) false,A,"Evidence shows that a sixth mass extinction is happening right now. Species are currently going extinct at the fastest rate since the dinosaurs died out. Dozens of species are going extinct every day. If this rate continues, as many as half of all remaining species could go extinct by 2050. Why are so many species going extinct today? Unlike previous mass extinctions, the sixth mass extinction is due mainly to human actions. "
the size of the human population creates many issues relating to the survival of other species.,(A) true (B) false,A,"Human populations are on the rise. The human population passed the 7 billion mark in October of 2011, and will pass 8 and 9 billion probably before the middle of the century. All these people will need resources such as places to live, food to eat, and water to drink, and they will use energy and create waste. Essentially, human population growth can effect all other causes of extinction. For example, more people on the Earth means more people contributing to global warming and pollution. More people also means more clearing of land for agriculture and development. Recall that development by humans often causes habitats to be destroyed. This destruction can force species to go extinct, or move somewhere else. "
the burning of fossil fuels,(A) changes the habitats of many species (B) warms the planet (C) can lead to species extinction (D) all of the above,D,"Burning fossil fuels releases many pollutants into the air. These pollutants include carbon monoxide, carbon dioxide, nitrogen dioxide, and sulfur dioxide. Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum. Power plants and factories account for more than a quarter of fossil fuel use. Power plants burn fossil fuels to generate electricity. Factories burn fossil fuels to power machines. Homes and other buildings also burn fossil fuels. The energy they release is used for heating, cooking, and other purposes. "
pollution,(A) changes the habitats of many species (B) comes from greenhouse gases (C) leads to species population increases (D) all of the above,A,"Modern agricultural practices produce a lot of pollution (Figure 1.1). Some pesticides are toxic. Dead zones grow as fertilizers drain off farmland and introduce nutrients into lakes and coastal areas. Farm machines and vehicles used to transport crops produce air pollutants. Pollutants enter the air, water, or are spilled onto the land. Moreover, many types of pollution easily move between air, water, and land. As a result, no location or organism  not even polar bears in the remote Arctic  is free from pollution. "
"if nothing changes from today, human population increases will result",(A) more greenhouse gases emitted (B) additional species extinction (C) more habit destruction (D) all of the above,D,"Every 20 minutes, the human population adds 3,500 more people. More people need more resources. For example, we now use five times more fossil fuels than we did in 1970. The human population is expected to increase for at least 40 years. What will happen to resource use? "
threats to soil include,(A) damage from greenhouse gases (B) damage from agricultural pesticides (C) damage from acid rain (D) all of the above,B,"Other human actions that put soil at risk include logging, mining, and construction. You can see examples of each in Figure 19.4. When forests are cut down, the soil is suddenly exposed to wind and rain. Without trees, there is no leaf litter to cover the ground and protect the soil. When leaf litter decays, it adds humus and nutrients to the soil. Mining and construction strip soil off the ground and leave the land bare. Paved roads and parking lots prevent rainwater from soaking into the ground. This increases runoff and the potential for soil erosion. "
threats to water include,(A) damage from greenhouse gases (B) damage from agricultural pesticides (C) damage from acid rain (D) all of the above,C,"Water scarcity can have dire consequences for the people, the economy, and the environment. Without adequate water, crops and livestock dwindle and people go hungry. Industry, construction, and economic development is halted, causing a nation to sink further into poverty. The risk of regional conflicts over scarce water resources rises. People die from diseases, thirst, or even in war over scarce resources. Californias population is growing by hundreds of thousands of people a year, but much of the state receives as much annual rainfall as Morocco. With fish populations crashing, global warming, and the demands of the countrys largest agricultural industry, the pressures on our water supply are increasing. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
chewing your food is the start of digestion.,(A) true (B) false,A,"Does the sight or smell of your favorite food make your mouth water? When this happens, you are getting ready for digestion. "
absorption of nutrients from food occurs in the stomach.,(A) true (B) false,B,"The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls that contract and relax to squeeze and mix food. This helps break the food into smaller pieces. It also helps mix the food with enzymes and other secretions in the stomach. For example, the stomach secretes the enzyme pepsin, which helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the lining of the stomach. However, most substances must undergo further digestion in the small intestine before they can be absorbed. The stomach stores the partly digested food until the small intestine is empty. Then a sphincter between the stomach and small intestine relaxes, allowing food to enter the small intestine. "
which of the following are organs of the digestive system?,(A) the liver (B) pancreas and gallbladder (C) b the stomach and intestine (D) c the mouth and esophagus (E) d All of the above are organs of the digestive system,D,"The mouth and stomach are just two of the organs of the digestive system. Other digestive system organs are the esophagus, small intestine, and large intestine. Below, you can see that the digestive organs form a long tube ( Figure 1.1). In adults, this tube is about 30 feet long! At one end of the tube is the mouth. At the other end is the anus. Food enters the mouth and then passes through the rest of the digestive system. Food waste leaves the body through the anus. The organs of the digestive system are lined with muscles. The muscles contract, or tighten, to push food through the system ( Figure 1.2). The muscles contract in waves. The waves pass through the digestive system like waves through a slinky. This movement of muscle contractions is called peristalsis. Without peristalsis, food would not be able to move through the digestive system. Peristalsis is an involuntary process, which means that it occurs without your conscious control. The liver, gallbladder, and pancreas are also organs of the digestive system ( Figure 1.1). Food does not pass through these three organs. However, these organs are important for digestion. They secrete or store enzymes or other chemicals that are needed to help digest food chemically. "
the mixing of food with stomach juices is an example of,(A) mechanical digestion (B) chemical digestion (C) absorption (D) elimination,B,"The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls that contract and relax to squeeze and mix food. This helps break the food into smaller pieces. It also helps mix the food with enzymes and other secretions in the stomach. For example, the stomach secretes the enzyme pepsin, which helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the lining of the stomach. However, most substances must undergo further digestion in the small intestine before they can be absorbed. The stomach stores the partly digested food until the small intestine is empty. Then a sphincter between the stomach and small intestine relaxes, allowing food to enter the small intestine. "
the mixing of food with saliva is the beginning of what process?,(A) mechanical digestion (B) chemical digestion (C) absorption (D) eating,B,"The mouth is the first digestive organ that food enters. The sight, smell, or taste of food stimulates the release of saliva and digestive enzymes by salivary glands inside the mouth. Saliva wets the food, which makes it easier to break up and swallow. The enzyme amylase in saliva begins the chemical digestion of starches to sugars. Your teeth help to mechanically digest food. Look at the different types of human teeth in Figure 17.13. Sharp teeth in the front of the mouth cut or tear food when you bite into it. Broad teeth in the back of the mouth grind food when you chew. Your tongue helps mix the food with saliva and enzymes and also helps you swallow. When you swallow, a lump of chewed food passes from the mouth into a tube in your throat called the pharynx. From the pharynx, the food passes into the esophagus. "
the majority of absorption occurs in the,(A) stomach (B) small intestine (C) large intestine (D) mouth,B,"The small intestine a is narrow tube that starts at the stomach and ends at the large intestine ( Figure 1.1). In adults, the small intestine is about 23 feet long. Chemical digestion takes place in the first part of the small intestine. Many enzymes and other chemicals are secreted here. The small intestine is also where most nutrients are absorbed into the blood. The later sections of the small intestines are covered with tiny projections called villi ( Figure 1.3). Villi contain very tiny blood vessels. Nutrients are absorbed into the blood through these tiny vessels. There are millions of villi, so, altogether, there is a very large area for absorption to take place. In fact, villi make the inner surface area of the small intestine 1,000 times larger than it would be without them. The entire inner surface area of the small intestine is about as big as a basketball court! The small intestine is much longer than the large intestine. So why is it called small? If you compare small and large intestines ( Figure 1.1), you will see the small intestine is smaller in width than the large intestine. "
another name for the digestive tube is the,(A) gut (B) digestive tract (C) gastrointestinal tract (D) mouth to the anus,C,"The organs in Figure 17.10 make up the gastrointestinal (GI) tract. This is essentially a long tube that connects the mouth to the anus. Food enters the mouth and then passes through the rest of the GI tract. Food waste leaves the body through the anus. In adults, the GI tract is more than 9 meters (30 feet) long! Organs of the GI tract are covered by muscles that contract to keep food moving along. A series of involuntary muscle contractions moves rapidly along the tract, like a wave travelling through a spring toy. The muscle contractions are called peristalsis. The diagram in Figure 17.11 shows how peristalsis works. "
your genome is all of your genetic information.,(A) true (B) false,A,A species genome consists of all of its genetic information. The human genome consists of the complete set of genes in the human organism. Its all the DNA of a human being. 
all the bases that make up the human genome have been sequenced.,(A) true (B) false,A,"The Human Genome Project was launched in 1990. It was an international effort to sequence all 3 billion bases in human DNA. Another aim of the project was to identify the more than 20,000 human genes and map their locations on chromosomes. The logo of the Human Genome Project in Figure 6.13 shows that the project brought together experts in many fields. The Human Genome Project was completed in 2003. It was one of the greatest feats of modern science. It provides a complete blueprint for a human being. Its like having a very detailed manual for making a human organism. "
how many bases make up the human genome?,(A) 4 (B) about 300 (C) 000 (D) c about 3 (E) 000 (F) 000 (G) d about 3 (H) 000 (I) 000 (J) 000,C,"The Human Genome Project was launched in 1990. It was an international effort to sequence all 3 billion bases in human DNA. Another aim of the project was to identify the more than 20,000 human genes and map their locations on chromosomes. The logo of the Human Genome Project in Figure 6.13 shows that the project brought together experts in many fields. The Human Genome Project was completed in 2003. It was one of the greatest feats of modern science. It provides a complete blueprint for a human being. Its like having a very detailed manual for making a human organism. "
how many genes does it take to make a human?,(A) about 2 (B) 000 (C) b about 20 (D) 000 (E) c about 20 (F) 000 (G) 000 (H) d about 20 (I) 000 (J) 000 (K) 000,B,"The Human Genome Project was launched in 1990. It was an international effort to sequence all 3 billion bases in human DNA. Another aim of the project was to identify the more than 20,000 human genes and map their locations on chromosomes. The logo of the Human Genome Project in Figure 6.13 shows that the project brought together experts in many fields. The Human Genome Project was completed in 2003. It was one of the greatest feats of modern science. It provides a complete blueprint for a human being. Its like having a very detailed manual for making a human organism. "
which of the following is not an outcome of the human genome project?,(A) Technologies developed will reduce the cost of sequencing a person's genome (B) It will allow you to analyze your own genome (C) It will be easier to identify genetic disease genes (D) It will allow professionals to determine if you are at risk for specific diseases,B,"The Human Genome Project was launched in 1990. It was an international effort to sequence all 3 billion bases in human DNA. Another aim of the project was to identify the more than 20,000 human genes and map their locations on chromosomes. The logo of the Human Genome Project in Figure 6.13 shows that the project brought together experts in many fields. The Human Genome Project was completed in 2003. It was one of the greatest feats of modern science. It provides a complete blueprint for a human being. Its like having a very detailed manual for making a human organism. "
knowing a person is at risk for developing a genetic disease,(A) would allow that person to make lifestyle changes (B) would allow that person to seek preventative medical care (C) would allow that person to have their genome studied (D) both (a,D,Sequencing the human genome has increased our knowledge of genetic disorders. Genetic disorders are diseases caused by mutations. Many genetic disorders are caused by mutations in a single gene. Others are caused by abnormal numbers of chromosomes. 
analysis of your own genome,(A) could give you a genetic disorder (B) could make you very sick (C) could determine if you are at risk for specific diseases (D) all of the above,C,"A persons genome is all of his or her genetic information. In other words, the human genome is all the information that makes us human. And unless you have an identical twin, your genome is unique. No one else has a genome just like yours, though all our genomes are similar. The Human Genome Project ( Figure 1.1) was an international effort to sequence all 3 billion bases that make up our DNA and to identify within this code more than 20,000 human genes. Scientists also completed a chromosome map, identifying where the genes are located on each of the chromosomes. The Human Genome Project was completed in 2003. Though the Human Genome Project is finished, analysis of the data will continue for many years. To say the Human Genome Project has been beneficial to mankind would be an understatement. Exciting applications of the Human Genome Project include the following: The genetic basis for many diseases can be more easily determined. Now there are tests for over 1,000 genetic disorders. The technologies developed during this effort, and since the completion of this project, will reduce the cost of sequencing a persons genome. This may eventually allow many people to sequence their individual genome. Analysis of your own genome could determine if you are at risk for specific diseases. Knowing you might be genetically prone to a certain disease would allow you to make preventive lifestyle changes or have medical screenings. To complete the Human Genome Project, all 23 pairs of chromosomes in the human body were sequenced. Each chromo- some contains thousands of genes. This is a karyotype, a visual representation of an individuals chromosomes lined up by size. The video Our Molecular Selves discusses the human genome, and is available at  or  . Genome, Unlocking Lifes Code is the Smithsonian National Museum of Natural Historys exhibit on the human genome. See http://unlockinglifescode.org to visit the exhibit. Click image to the left or use the URL below. URL: "
planet earth has unlimited resources.,(A) true (B) false,B,The ocean floor is rich in resources. The resources include both living and nonliving things. 
"the human population is running out of resources, so it shows logistic growth.",(A) true (B) false,B,"Population growth can be described with two models, based on the size of the population and necessary resources. These two types of growth are known as exponential growth and logistic growth. If a population is given unlimited amounts of resources, such as food and water, land if needed, moisture, oxygen, and other environmental factors, it will grow exponentially. Exponential growth occurs as a population grows larger, dramatically increasing the growth rate. This is shown as a ""J-shaped"" curve below ( Figure 1.3). You can see that the population grows slowly at first, but as time passes, growth occurs more and more rapidly. Growth of populations according to ex- ponential (or J-curve) growth model (left) and logistic (or S-curve) growth model (right). Time is plotted on the x-axis, and population size is plotted on the y-axis. In nature, organisms do not usually have ideal environments with unlimited food. In nature, there are limits. Sometimes, there will be plenty of food. Sometimes, a fire will wipe out all of the available nutrients. Sometimes a predator will kill many individuals in a population. How do you think these limits affect the way organisms grow? "
how long did it take for the human population to increase from 6 billion to 7 billion people?,(A) 1 year (B) 12 years (C) 25 years (D) 50 years,B,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
how long did it take for the human population to increase from 1 billion to 2 billion people?,(A) about 25 years (B) about 50 years (C) about 100 years (D) over 120 years,D,"Not only has the population increased, but the rate of population growth has increased (Figure 1.2). The population was estimated to reach 7 billion in 2012, but it did so in 2011, just 12 years after reaching 6 billion. Human population from 10,000 BC through 2000 AD, showing the exponential increase in human population that has occurred in the last few centuries. The amount of time between the addition of each one billion people to the planets population, including speculation about the future. Although population continues to grow rapidly, the rate that the growth rate is increasing has declined. Still, a recent estimate by the United Nations estimates that 10.1 billion people will be sharing this planet by the end of the century. The total added will be about 3 billion people, which is more than were even in existence as recently as 1960. "
which is the first stage of human population growth?,(A) Population size continues to grow (B) Birth rates equal death rates and populations become stable (C) Birth and death rates are high and population growth is stable (D) Total population size may level off,C,"On the other hand, if you look at human population growth in specific countries, you may see a different pattern. On the level of a country, the history of human population growth can be divided into five stages, as described in Table 1.1. Some countries have very high birth rates, in some countries the growth rate has stabilized, and in some countries the growth rate is in decline. Stage 1 2 3 4 5 Description Birth and death rates are high and population growth is stable. This occurred in early human history. Significant drop in death rate, resulting in exponential growth. This occurred in 18th- and 19th-century Eu- rope. Population size continues to grow. Birth rates equal death rates and populations become stable. Total population size may level off. The United Nations and the U.S. Census Bureau predict that by 2050, the Earth will be populated by 9.4 billion people. Other estimates predict 10 to 11 billion. "
which is the last stage of human population growth?,(A) Population size continues to grow (B) Birth rates equal death rates and populations become stable (C) Birth and death rates are high and population growth is stable (D) Total population size may level off,D,The growth of the human population has started to slow down. You can see this in Figure 18.21. It may stop growing by the mid 2000s. Scientists think that the human population will peak at about 9 billion people. What will need to change for the population to stop growing then? 
"by the year 2050, how many people will inhabit the planet?",(A) about 7 billion (B) about 8 to 9 billion (C) about 9 to 11 billion (D) over 15 billion,C,"As of 2014, there were more than 7 billion human beings on planet Earth. That number is increasing rapidly. More than 200,000 people are added to the human population each day! At this rate, the human population will pass 9 billion by 2050. Many experts think that the human population has reached its carrying capacity. It has already harmed the environ- ment. An even larger human population may cause severe environmental problems. It could also lead to devastating outbreaks of disease, starvation, and war. To solve these problems, two approaches may be needed: Slow down human population growth so there are fewer people. Distribute Earths resources more fairly so that everyone has enough. Hopefully, we will act before its too late. Otherwise, the planet may be ruined for future generations of human beings and other species. "
bones are made of cartilage and ligaments.,(A) true (B) false,B,"How important is your skeleton? Can you imagine your body without it? You would be a wobbly pile of muscle and internal organs, and you would not be able to move. The adult human skeleton has 206 bones, some of which are named below ( Figure 1.1). Bones are made up of living tissue. They contain many different types of tissues. Cartilage, a dense connective tissue, is found at the end of bones and is made of tough protein fibers. Cartilage creates smooth surfaces for the movement of bones that are next to each other, like the bones of the knee. Ligaments are made of tough protein fibers and connect bones to each other. Your bones, cartilage, and ligaments make up your skeletal system. "
ligaments create smooth surfaces for the movement of bones.,(A) true (B) false,B,"A joint is a place where two or more bones of the skeleton meet. There are three different types of joints based on the degree to which they allow movement of the bones: immovable, partly movable, and movable joints. Immovable joints do not allow the bones to move at all. In these joints, the bones are fused together by very tough collagen. Examples of immovable joints include the joints between bones of the skull. You can see them in Figure 16.12. Partly movable joints allow very limited movement. In these joints, the bones are held together by cartilage, which is more flexible than collagen. Examples of partly moveable joints include the bones of the rib cage. Movable joints allow the greatest movement and are the most common. In these joints, the bones are connected by ligaments. The surfaces of the bones at the joints are covered with a smooth layer of cartilage. It reduces friction between the bones when they move. The space between the bones is also filled with a liquid called synovial fluid. It helps to cushion the bones. There are several different types of movable joints. You can see three of them in Figure 16.13. Move these three joints in your own skeleton to experience the range of motion each allows. "
which best describes the skeleton of a baby?,(A) A skeleton of only cartilage and other connective tissues (B) A skeleton of bones with areas of cartilage for growth (C) A skeleton that is just beginning to harden (D) A skeleton just like that of an adult (E) only smaller,B,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
what is cartilage?,(A) A Soft connective tissue in spongy bone (B) A band of fibrous connective tissue that holds bones together (C) A dense connective tissue that provides a smooth surface for the movement (D) A tough (E) fibrous membrane that covers the outer surface of bone,C,"The vertebrate endoskeleton is made of bone and cartilage. Cartilage is a tough, flexible tissue that contains a protein called collagen. Bone is a hard tissue consisting of a collagen framework that is filled in with minerals such as calcium. Bone is less flexible than cartilage but stronger. A bony endoskeleton allows an animal to grow larger and heavier than a cartilage endoskeleton would. Bone also provides more protection for soft tissues and internal organs. "
what is the light and porous material at eh center of bone?,(A) spongy bone (B) compact bone (C) bone marrow (D) the periosteum,A,"Bones come in many different shapes and sizes, but they are all made of the same materials. Bones are organs, and recall that organs are made up of two or more types of tissues. The two main types of bone tissue are compact bone and spongy bone ( Figure 1.2). Compact bone makes up the dense outer layer of bones. Spongy bone is found at the center of the bone and is lighter and more porous than compact bone. Bones look tough, shiny, and white because they are covered by a layer called the periosteum. Many bones also contain a soft connective tissue called bone marrow in the pores of the spongy bone. Bone marrow is where blood cells are made. Bones are made up of different types of tissues. "
which of the following are functions of the skeleton?,(A) to store calcium (B) to support the body against the pull of gravity (C) to protect the soft organs of the body (D) All of the above are functions of the skeleton,D,"Your skeletal system gives shape and form to your body, but it also plays other important roles. The main functions of the skeletal system include: The skeletal system is made up of bones, cartilage, and ligaments. The skeletal system has many important functions in your body. What bones protect the heart and lungs? What protects the brain? Support. The skeleton supports the body against the pull of gravity, meaning you dont fall over when you stand up. The large bones of the lower limbs support the rest of the body when standing. Protection. The skeleton supports and protects the soft organs of the body. For example, the skull surrounds the brain to protect it from injury. The bones of the rib cage help protect the heart and lungs. Movement. Bones work together with muscles to move the body. Making blood cells. Blood cells are mostly made inside certain types of bones. "
why does the skeleton stop growing in length?,(A) Because the growth plates stop working (B) Because there is not enough calcium and other nutrients in the body (C) Because the cartilage in the growth plate has been replaced by bone (D) Because the bones reach their maximum length,C,"Early in the development of a human fetus, the skeleton is made entirely of cartilage. The relatively soft cartilage gradually changes to hard bone through ossification. This is a process in which mineral deposits replace cartilage in bone. At birth, several areas of cartilage remain, including the ends of the long bones in the arms and legs. This allows these bones to keep growing in length during childhood. By the late teens or early twenties, all of the cartilage has been replaced by bone. Bones cannot grow in length after this point has been reached. However, bones can continue to grow in width. They are stimulated to grow thicker when they are put under stress by muscles. Weight-bearing activities such as weight lifting can increase growth in bone width. "
sealing up your home keeps air pollution out.,(A) true (B) false,B,"Its easier to control the quality of indoor air than outdoor air. Steps home owners can take to improve indoor air quality include: keeping the home clean so it is as free as possible from dust, mold, and pet dander. choosing indoor furniture, flooring, and paints that are low in toxic compounds such as VOCs (volatile organic compounds). making sure that fuel-burning appliances are working correctly and venting properly. installing carbon monoxide alarms like the one in Figure 25.4 at every level of the home. "
secondhand smoke can cause severe health issues.,(A) true (B) false,A,"Cigarette smoking can cause serious diseases, so not smoking or quitting now are the most effective ways to reduce your risk of developing chronic respiratory diseases, such as lung cancer. Avoiding (or stopping) smoking is the single best way to prevent many respiratory and cardiovascular diseases. Also, do your best to avoid secondhand smoke. "
which of the following is a biological source of indoor air pollution?,(A) decomposed hair (B) pollen (C) mold (D) all of the above,D,"Recall that air pollution is due to chemical substances and particles released into the air mainly by human actions. When most people think of air pollution, they think of the pollution outdoors. But it is just as easy to have indoor air pollution. Your home or school classroom probably doesnt get much fresh air. Sealing up your home reduces heating and cooling costs. But this also causes air pollution to stay trapped indoors. And people today usually spend a majority of their time indoors. So exposure to indoor air pollution can become a significant health risk. Indoor air pollutants include both chemical and biological pollutants. Chemical pollutants include the following: Radon, a radioactive gas released from the Earth in certain locations. It can become trapped inside buildings and increase your risk of cancer. Formaldehyde, a toxic gas emitted from building materials, such as carpeting and plywood. Volatile organic compounds (VOCs), which are given off by paint and solvents as they dry. They can cause cause long-term health effects. Secondhand smoke, which comes from breathing the smoke release from tobacco products. Secondhand smoke is also the smoke exhaled by a cigarette smoker. This smoke is extremely dangerous to human health. Carbon monoxide (CO), a toxic gas released by burning fossil fuels. It is often released indoors by faulty chimneys, gas-powered generators, or burning charcoal; it can be extremely dangerous. Dry cleaning fluids, such as tetrachloroethylene, which can be released from clothing days after dry cleaning. The past use of asbestos in factories and in homes. Asbestos is a very dangerous material, and it was used in many buildings ( Figure 1.1). Asbestos can cause cancer and other lung diseases. The use of asbestos is not allowed today. The use of asbestos in industry and do- mestic environments in the past, as in the asbestos-covered pipes in the oil-refining plant pictured here, has left a potentially very dangerous material in many busi- nesses. Biological sources of air pollution are also found indoors. These are produced from: Pet dander. Dust from tiny skin flakes and decomposed hair. Dust mites. Mold from walls, ceilings, and other structures. Air conditioning systems that can incubate certain bacteria and mold. Pollen, dust, and mold from houseplants, soil, and surrounding gardens. "
which of the following is a radioactive gas released from the earth?,(A) carbon monoxide (B) VOCs (C) radon (D) formaldehyde,C,"A low level of radiation occurs naturally in the environment. This is called background radiation. It comes from various sources. One source is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. A source of radiation that may be more dangerous is radon. Radon is a radioactive gas that forms in rocks underground. It can seep into basements and get trapped inside buildings. Then it may build up and become harmful to people who breathe it. Other sources of radiation are described in the interactive animation at this URL: http://w "
which of the following is extremely dangerous to your health?,(A) asbestos (B) carbon monoxide (C) secondhand smoke (D) all of the above,D,"Different pollutants have different health effects: Lead is the most common toxic material and is responsible for lead poisoning. Carbon monoxide can kill people in poorly ventilated spaces, such as tunnels. Nitrogen and sulfur-oxides cause lung disease and increased rates of asthma, emphysema, and viral infections such as the flu. Ozone damages the human respiratory system, causing lung disease. High ozone levels are also associated with increased heart disease and cancer. Particulates enter the lungs and cause heart or lung disease. When particulate levels are high, asthma attacks are more common. By some estimates, 30,000 deaths a year in the United States are caused by fine particle pollution. "
which of the following is a toxic gas released by burning fossil fuels?,(A) radon (B) volatile organic compounds (C) carbon monoxide (D) asbestos,C,"Burning fossil fuels releases many pollutants into the air. These pollutants include carbon monoxide, carbon dioxide, nitrogen dioxide, and sulfur dioxide. Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum. Power plants and factories account for more than a quarter of fossil fuel use. Power plants burn fossil fuels to generate electricity. Factories burn fossil fuels to power machines. Homes and other buildings also burn fossil fuels. The energy they release is used for heating, cooking, and other purposes. "
"to limit your exposure to indoor air pollution, you should",(A) have secondhand smoke detectors in your home (B) limit your exposure to pesticides and cleaning fluids (C) only use toxic substances outside (D) all of the above,B,"You may be able to avoid some of the health effects of outdoor air pollution by staying indoors on high-pollution days. However, some indoor air is just as polluted as outdoor air. "
babies grow fastest during the first year of life.,(A) true (B) false,A,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
a baby must be able to walk to be a toddler.,(A) true (B) false,B,"There are numerous milestones that occur during the first few years of childhood. These include the use of language, walking and running, understanding simple concepts, pretend play, the development of fine motor skills, the development of independence, Children develop better motor skills as they get older. having temper tantrums, demonstrating separation anxiety, becoming fully potty-trained, showing natural curiosity. "
"during infancy, a baby",(A) doubles in weight and triples in length (B) doubles in height and triples in length (C) doubles in length and triples in weight (D) gains 10 pounds and 10 inches,C,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
many baby teeth start to come in at about,(A) 4 months (B) 6 months (C) 8 months (D) 10 months,B,"The first year after birth is called infancy. Infancy is a period when the baby grows very fast. During infancy, the baby doubles in length and triples in weight. Other important changes also happen during infancy: The babys teeth start to come in, usually at about six months of age ( Figure 1.1). The baby starts smiling, paying attention to other people, and grabbing toys. The baby begins making babbling sounds. By the end of the first year, the baby is starting to say a few words, such as mama and dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. Childhood begins after the babys first birthday and continues until the teen years. Between one and three years of age, a child is called a toddler. During the toddler stage, growth is still fast, but not as fast as it was during infancy. A toddler learns many new words. The child even starts putting together words in simple sentences. Motor skills also develop quickly during this stage. By age three, most children can run and climb steps. They can hold crayons and scribble with them. They can also feed themselves and use the toilet. From age three until the teens, growth is slower. The body also changes shape. The arms and legs get longer compared to the trunk. Children continue to develop new motor skills. For example, many young children learn how to ride a tricycle and then a bicycle. Most also learn how to play games and sports ( Figure 1.2). By age six, children start losing their baby teeth. Their permanent teeth begin coming in to replace them. They also start school and learn how to read and write. They develop friendships and become less dependent on their parents. "
the best toy for an infant is one that the baby,(A) can play with like a doll (B) can catch like a ball (C) can put in its mouth (D) all of the above,C,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
when do many babies begin to walk?,(A) by 6 months of age (B) by 9 months of age (C) by 12 months of age (D) by 18 months of age,C,"The first year of life after birth is called infancy. During infancy, a baby grows very quickly. The babys length typically doubles and her weight triples by her first birthday. Many other important changes also occur during infancy: The baby starts smiling, usually by about 6 weeks of age (see Figure 22.10). The baby starts noticing people and grabbing toys and other objects The baby teeth start to come in, usually by 6 months of age. The baby begins making babbling sounds. By the end of the first year, the baby may be saying a few words, such as Mama and Dada. The baby learns to sit, crawl, and stand. By the end of the first year, the baby may be starting to walk. "
many young children repeatedly ask why? this is an example of,(A) understanding simple concepts (B) their natural curiosity (C) a fine motor skill (D) pretend play,B,"Are you like the teen in Figure 1.1? Do you ever wonder why things happen? Do you like to find out how things work? If so, then you are already thinking like a scientist. Scientists also wonder how and why things happen. They are curious about the world. To answer their questions, they make many observations. Then they use logic to draw general conclusions. "
"prior to darwin, many people believed earth was only about 6,000 years old.",(A) true (B) false,A,"During the 18th and 19th centuries, geologists tried to estimate the age of Earth with indirect techniques. What methods can you think of for doing this? One example is that by measuring how much sediment a stream deposited in a year, a geologist might try to determine how long it took for a stream to deposit an ancient sediment layer. Not surprisingly, these methods resulted in wildly different estimates. A relatively good estimate was produced by the British geologist Charles Lyell, who thought that 240 million years had passed since the appearance of the first animals with shells. Today scientists know that this event occurred about 530 million years ago. In 1892, William Thomson (later known as Lord Kelvin) calculated that the Earth was 100 million years old, which he later lowered to 20 million years. He did this systematically assuming that the planet started off as a molten ball and calculating the time it would take for it to cool to its current temperature. This estimate was a blow to geologists and supporters of Charles Darwins theory of evolution, which required an older Earth to provide time for geological and evolutionary processes to take place. Kelvins calculations were soon shown to be flawed when radioactivity was discovered in 1896. What Kelvin didnt know is that radioactive decay of elements inside Earths interior provides a steady source of heat. He also didnt know that the mantle is able to flow and so convection moves heat from the interior to the surface of the planet. Thomson had grossly underestimated Earths age. "
many people believed that organisms never change and never go extinct.,(A) true (B) false,A,"Most of the organisms that once lived on Earth are now extinct. Earths environment has changed many times. Many organisms could not adapt to the changes. They died out. The organisms that did survive passed traits on to their offspring. The changes added up, eventually producing the species we see today. We study fossils to see the organisms that lived at certain times. We can see how those organisms changed with time. We can see how they evolved. "
"who suggested the earth must be over 6,000 years old, because of all the geological changes.",(A) Lyell (B) Lamarck (C) Wallace (D) Darwin,A,"During the 18th and 19th centuries, geologists tried to estimate the age of Earth with indirect techniques. What methods can you think of for doing this? One example is that by measuring how much sediment a stream deposited in a year, a geologist might try to determine how long it took for a stream to deposit an ancient sediment layer. Not surprisingly, these methods resulted in wildly different estimates. A relatively good estimate was produced by the British geologist Charles Lyell, who thought that 240 million years had passed since the appearance of the first animals with shells. Today scientists know that this event occurred about 530 million years ago. In 1892, William Thomson (later known as Lord Kelvin) calculated that the Earth was 100 million years old, which he later lowered to 20 million years. He did this systematically assuming that the planet started off as a molten ball and calculating the time it would take for it to cool to its current temperature. This estimate was a blow to geologists and supporters of Charles Darwins theory of evolution, which required an older Earth to provide time for geological and evolutionary processes to take place. Kelvins calculations were soon shown to be flawed when radioactivity was discovered in 1896. What Kelvin didnt know is that radioactive decay of elements inside Earths interior provides a steady source of heat. He also didnt know that the mantle is able to flow and so convection moves heat from the interior to the surface of the planet. Thomson had grossly underestimated Earths age. "
who proposed that traits acquired during ones lifetime could be passed to the next generation?,(A) Lyell (B) Lamarck (C) Wallace (D) Darwin,B,"What does the word ""inherit"" mean? You may have inherited something of value from a grandparent or another family member. To inherit is to receive something from someone who came before you. You can inherit objects, but you can also inherit traits. For example, you can inherit a parents eye color, hair color, or even the shape of your nose and ears! Genetics is the study of inheritance. The field of genetics seeks to explain how traits are passed on from one generation to the next. In the late 1850s, an Austrian monk named Gregor Mendel ( Figure 1.1) performed the first genetics experiments. To study genetics, Mendel chose to work with pea plants because they have easily identifiable traits ( Figure 1.2). For example, pea plants are either tall or short, which is an easy trait to observe. Furthermore, pea plants grow quickly, so he could complete many experiments in a short period of time. Mendel also used pea plants because they can either self-pollinate or be cross-pollinated. Self-pollination means that only one flower is involved; the flowers own pollen lands on the female sex organs. Cross pollination is done by hand by moving pollen from one flower to the stigma of another (just like bees do naturally). As a result, one plants sex cells combine with another plants sex cells. This is called a ""cross."" These crosses produce offspring Gregor Mendel, the ""father"" of genetics. Characteristics of pea plants. (or ""children""), just like when male and female animals mate. Since Mendel could move pollen between plants, he could carefully control and then observe the results of crosses between two different types of plants. He studied the inheritance patterns for many different traits in peas, including round seeds versus wrinkled seeds, white flowers versus purple flowers, and tall plants versus short plants. Because of his work, Mendel is considered the ""Father of Genetics."" "
who developed a theory of evolution similar to darwins?,(A) Lamarck (B) Lyell (C) Wallace (D) no one,C,"Besides his observations on the Beagle, other influences helped Darwin develop his theory of evolution by natural selection. These included his knowledge of plant and animal breeding and the ideas of other scientists. "
"during darwins voyage, he observed fossils of sea life in the mountains? this is evidence of",(A) fish living in the mountains (B) dramatic geological changes during Earth’s history (C) the evolution of sea life into animals that live in the mountains (D) all of the above,B,"How did Darwin come up with the theory of evolution by natural selection? A major influence was an amazing scientific expedition he took on a ship called the Beagle. Darwin was only 22 years old when the ship set sail. The trip lasted for almost five years and circled the globe. Figure 7.2 shows the route the ship took. It set off from Plymouth, England in 1831. It wouldnt return to Plymouth until 1836. Imagine setting out for such an incredible adventure at age 22, and youll understand why the trip had such a big influence on Darwin. Darwins job on the voyage was to observe and collect specimens whenever the ship went ashore. This included plants, animals, rocks, and fossils. Darwin loved nature, so the job was ideal for him. During the long voyage, he made many observations that helped him form his theory of evolution. Some of his most important observations were made on the Galpagos Islands. The 16 Galpagos Islands lie 966 kilometers (about 600 miles) off the west coast of South America. (You can see their location on the map in Figure 7.2.) Some of the animals Darwin observed on the islands were giant tortoises and birds called finches. Watch this video for an excellent introduction to Darwin, his voyage, and the Galpagos: "
"darwin is buried in westminster abbey in london, the final resting place of many of englands kings and queens. this honor suggests",(A) the influence Darwin had on everyone else (B) the acceptance of Darwin’s work (C) the important place in history of Darwin (D) all of the above,D,"When Darwin returned to England five years later, in 1836, at the end of his voyage, he did not rush to announce his discoveries. Unlike other naturalists before him, Darwin did not want to present any ideas unless he had strong evidence supporting them. Instead, once Darwin returned to England, he spent over twenty years examining specimens, talking with other scientists and collecting more information before he presented his theories. Some of Darwins ideas conflicted with widely held beliefs, including those from religious leaders. At that time, many people believed that organisms never change and never go extinct, and that the world was only about 6,000 years old, always existing in the same way, never changing. These beliefs delayed Darwin in presenting his findings. How did Darwin come up with his theories? Charles Darwin was influenced by the ideas of several people. 1. Before the voyage of the Beagle, Jean-Baptiste Lamarck proposed the idea that species change over time. However, Darwin differed with Lamarck on several key points. Lamarck proposed that traits acquired during ones lifetime could be passed to the next generation. Darwin did not agree with this. 2. The findings of Charles Lyell, a well-known geologist, also influenced Darwin. Lyells writings taught Darwin about geology, paleontology, and the changing Earth. Lyells findings suggested the Earth must be much older than 6,000 years. And the evolution of life, as Darwin was developing his ideas, would definitely take much longer than just 6,000 years. During the Voyage of the Beagle, Darwin observed fossils of sea life high up in the mountains. What must happen to the Earth for this to occur? Darwin, using the readings of Lyell, took this as evidence of a constantly changing Earth. 3. After the Voyage of the Beagle, another naturalist, Alfred Russel Wallace ( Figure 1.1), developed a similar theory of evolution by natural selection. Wallace toured South America and made similar observations to Darwins. Darwin and Wallace presented their theories and evidence in public together. Due to the large number of observations and conclusions he made, Darwin is mostly credited and associated with this theory. Alfred Wallace developed a similar theory of evolution by natural selection. Imagine developing a theory that conflicted with widely held beliefs of the time, as Darwin did. Imagine pulling together material from all these different people, adding his own findings, and turning it all into his theory. Imag- ine the torment Darwin must have endured during this time, knowing the skepticism that would follow the release of his findings. But, upon his death, Darwin was given one of the highest honors in England. Darwin is buried in Westminster Abbey, the final resting place of many of Englands kings and queens. Why was he buried in such an important spot? "
"if you think someone has a spinal cord injury, take him or her to the hospital as fast as possible.",(A) true (B) false,B,"A spinal cord injury is damage to any part of the spinal cord or nerves at the end of the spinal canal. This injury often causes permanent changes in strength, sensation and other body functions below the site of the injury. Spinal cord injuries make it difficult for messages to travel between the brain and body. They may cause a person to lose the ability to feel or move parts of the body. This is called paralysis. Whether paralysis occursand what parts of the body are affected if it doesdepends on the location and seriousness of the injury. In addition to car crashes and sports injuries, diving accidents are a common cause of spinal cord injuries. Quadriplegia means your arms, hands, trunk, legs and pelvic organs are all affected by your spinal cord injury. Paraplegia means the paralysis affects all or part of the trunk, legs and pelvic organs. These people can still use their arms and hands. Some people recover from spinal cord injuries. But many people are paralyzed for life. Thanks to the work of Christopher Reeve ( Figure 1.1), more research is being done on spinal cord injuries now than ever before. For example, scientists are trying to discover ways to regrow damaged spinal cord neurons. If you suspect that someone has a back or neck injury: dont move the injured person as permanent paralysis and other serious complications may result, call 911 or your local emergency medical assistance number, keep the person very still, place heavy towels on both sides of the neck or hold the head and neck to prevent them from moving, until emergency care arrives, provide basic first aid, such as stopping any bleeding and making the person comfortable, without moving the head or neck. Former ""man of steel"" Superman star Christopher Reeve (September 25, 1952 October 10, 2004) was paralyzed from the neck down in a fall from a horse. The injury crushed his spinal cord so his brain could no longer communicate with his body. "
"if someone loses consciousness, chances are they have a brain injury.",(A) true (B) false,A,"Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children. The mildest and most common type of brain injury is a concussion. This is a bruise on the surface of the brain. It may cause temporary problems such as headache, drowsiness, and confusion. Most concussions in young people occur when they are playing sports, especially contact sports like football. Other sports, like soccer, boxing, baseball, lacrosse, skateboarding, and hockey can also result in concussions. A concussion normally heals on its own in a few days. A single concussion is unlikely to cause permanent damage. But repeated concussions may lead to lasting problems. People who have had two or more concussions may have life-long difficulties with memory, learning, speech, or balance. For this reason, concussions are treated very seriously among athletes and in professional sports. You can see an animation of how a concussion occurs by visiting  A person with a serious brain injury usually suffers permanent brain damage. These brain injuries usually occur when an external mechanical force, such as a violent blow or jolt to the head or body, causes brain dysfunction. An object penetrating the skull, such as a bullet or a shattered piece of the skull, also can cause traumatic brain injury. As a result, the person may have trouble talking or controlling body movements. Symptoms depend on what part of the brain was injured. Serious brain injuries can also cause personality changes and problems with mental abilities such as memory. Medicines, counseling, and other treatments may help people with serious brain injuries recover from, or at least learn to cope with, their disabilities. Symptoms of severe brain injuries include the loss of consciousness from several minutes to hours, profound confusion, slurred speech, the inability to awaken from sleep, seizures, loss of coordination, persistent headache or headache that worsens. "
which of the following is a symptom of a severe brain injury?,(A) profound confusion (B) seizures (C) slurred speech (D) all of the above,D,"Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children. The mildest and most common type of brain injury is a concussion. This is a bruise on the surface of the brain. It may cause temporary problems such as headache, drowsiness, and confusion. Most concussions in young people occur when they are playing sports, especially contact sports like football. Other sports, like soccer, boxing, baseball, lacrosse, skateboarding, and hockey can also result in concussions. A concussion normally heals on its own in a few days. A single concussion is unlikely to cause permanent damage. But repeated concussions may lead to lasting problems. People who have had two or more concussions may have life-long difficulties with memory, learning, speech, or balance. For this reason, concussions are treated very seriously among athletes and in professional sports. You can see an animation of how a concussion occurs by visiting  A person with a serious brain injury usually suffers permanent brain damage. These brain injuries usually occur when an external mechanical force, such as a violent blow or jolt to the head or body, causes brain dysfunction. An object penetrating the skull, such as a bullet or a shattered piece of the skull, also can cause traumatic brain injury. As a result, the person may have trouble talking or controlling body movements. Symptoms depend on what part of the brain was injured. Serious brain injuries can also cause personality changes and problems with mental abilities such as memory. Medicines, counseling, and other treatments may help people with serious brain injuries recover from, or at least learn to cope with, their disabilities. Symptoms of severe brain injuries include the loss of consciousness from several minutes to hours, profound confusion, slurred speech, the inability to awaken from sleep, seizures, loss of coordination, persistent headache or headache that worsens. "
people who have had two or more concussions may have life-long difficulties with,(A) memory (B) learning (C) and speech (D) b eating and sleeping (E) c walking (F) d all of the above,A,"Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children. The mildest and most common type of brain injury is a concussion. This is a bruise on the surface of the brain. It may cause temporary problems such as headache, drowsiness, and confusion. Most concussions in young people occur when they are playing sports, especially contact sports like football. Other sports, like soccer, boxing, baseball, lacrosse, skateboarding, and hockey can also result in concussions. A concussion normally heals on its own in a few days. A single concussion is unlikely to cause permanent damage. But repeated concussions may lead to lasting problems. People who have had two or more concussions may have life-long difficulties with memory, learning, speech, or balance. For this reason, concussions are treated very seriously among athletes and in professional sports. You can see an animation of how a concussion occurs by visiting  A person with a serious brain injury usually suffers permanent brain damage. These brain injuries usually occur when an external mechanical force, such as a violent blow or jolt to the head or body, causes brain dysfunction. An object penetrating the skull, such as a bullet or a shattered piece of the skull, also can cause traumatic brain injury. As a result, the person may have trouble talking or controlling body movements. Symptoms depend on what part of the brain was injured. Serious brain injuries can also cause personality changes and problems with mental abilities such as memory. Medicines, counseling, and other treatments may help people with serious brain injuries recover from, or at least learn to cope with, their disabilities. Symptoms of severe brain injuries include the loss of consciousness from several minutes to hours, profound confusion, slurred speech, the inability to awaken from sleep, seizures, loss of coordination, persistent headache or headache that worsens. "
what is the most common cause of brain injuries?,(A) a violent blow to the head (B) falls (C) car accidents (D) sports injuries,B,"Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children. The mildest and most common type of brain injury is a concussion. This is a bruise on the surface of the brain. It may cause temporary problems such as headache, drowsiness, and confusion. Most concussions in young people occur when they are playing sports, especially contact sports like football. Other sports, like soccer, boxing, baseball, lacrosse, skateboarding, and hockey can also result in concussions. A concussion normally heals on its own in a few days. A single concussion is unlikely to cause permanent damage. But repeated concussions may lead to lasting problems. People who have had two or more concussions may have life-long difficulties with memory, learning, speech, or balance. For this reason, concussions are treated very seriously among athletes and in professional sports. You can see an animation of how a concussion occurs by visiting  A person with a serious brain injury usually suffers permanent brain damage. These brain injuries usually occur when an external mechanical force, such as a violent blow or jolt to the head or body, causes brain dysfunction. An object penetrating the skull, such as a bullet or a shattered piece of the skull, also can cause traumatic brain injury. As a result, the person may have trouble talking or controlling body movements. Symptoms depend on what part of the brain was injured. Serious brain injuries can also cause personality changes and problems with mental abilities such as memory. Medicines, counseling, and other treatments may help people with serious brain injuries recover from, or at least learn to cope with, their disabilities. Symptoms of severe brain injuries include the loss of consciousness from several minutes to hours, profound confusion, slurred speech, the inability to awaken from sleep, seizures, loss of coordination, persistent headache or headache that worsens. "
"if you think a person has a spinal cord injury, the one thing you should not do is",(A) keep the person very still (B) call for emergency medical assistance (C) rush them to a hospital (D) provide basic first aid,C,"A spinal cord injury is damage to any part of the spinal cord or nerves at the end of the spinal canal. This injury often causes permanent changes in strength, sensation and other body functions below the site of the injury. Spinal cord injuries make it difficult for messages to travel between the brain and body. They may cause a person to lose the ability to feel or move parts of the body. This is called paralysis. Whether paralysis occursand what parts of the body are affected if it doesdepends on the location and seriousness of the injury. In addition to car crashes and sports injuries, diving accidents are a common cause of spinal cord injuries. Quadriplegia means your arms, hands, trunk, legs and pelvic organs are all affected by your spinal cord injury. Paraplegia means the paralysis affects all or part of the trunk, legs and pelvic organs. These people can still use their arms and hands. Some people recover from spinal cord injuries. But many people are paralyzed for life. Thanks to the work of Christopher Reeve ( Figure 1.1), more research is being done on spinal cord injuries now than ever before. For example, scientists are trying to discover ways to regrow damaged spinal cord neurons. If you suspect that someone has a back or neck injury: dont move the injured person as permanent paralysis and other serious complications may result, call 911 or your local emergency medical assistance number, keep the person very still, place heavy towels on both sides of the neck or hold the head and neck to prevent them from moving, until emergency care arrives, provide basic first aid, such as stopping any bleeding and making the person comfortable, without moving the head or neck. Former ""man of steel"" Superman star Christopher Reeve (September 25, 1952 October 10, 2004) was paralyzed from the neck down in a fall from a horse. The injury crushed his spinal cord so his brain could no longer communicate with his body. "
sports in which a helmet should be required to prevent brain injuries include,(A) football (B) skateboarding (C) hockey (D) all of the above,D,"Brain injuries can range from mild to extremely severe, but even mild injuries need medical attention. Brain injuries can result from falls, car accidents, violence, sports injuries, and war and combat. Falls are the most common cause of brain injuries, particularly in older adults and young children. The mildest and most common type of brain injury is a concussion. This is a bruise on the surface of the brain. It may cause temporary problems such as headache, drowsiness, and confusion. Most concussions in young people occur when they are playing sports, especially contact sports like football. Other sports, like soccer, boxing, baseball, lacrosse, skateboarding, and hockey can also result in concussions. A concussion normally heals on its own in a few days. A single concussion is unlikely to cause permanent damage. But repeated concussions may lead to lasting problems. People who have had two or more concussions may have life-long difficulties with memory, learning, speech, or balance. For this reason, concussions are treated very seriously among athletes and in professional sports. You can see an animation of how a concussion occurs by visiting  A person with a serious brain injury usually suffers permanent brain damage. These brain injuries usually occur when an external mechanical force, such as a violent blow or jolt to the head or body, causes brain dysfunction. An object penetrating the skull, such as a bullet or a shattered piece of the skull, also can cause traumatic brain injury. As a result, the person may have trouble talking or controlling body movements. Symptoms depend on what part of the brain was injured. Serious brain injuries can also cause personality changes and problems with mental abilities such as memory. Medicines, counseling, and other treatments may help people with serious brain injuries recover from, or at least learn to cope with, their disabilities. Symptoms of severe brain injuries include the loss of consciousness from several minutes to hours, profound confusion, slurred speech, the inability to awaken from sleep, seizures, loss of coordination, persistent headache or headache that worsens. "
jawless fish were the first fish to evolve.,(A) true (B) false,A,"What defines a jawless fish? You can probably guess. A jawless fish is a fish without a jaw. But there are other features that are shared by this class of organisms. Why would such an organism evolve? These fish were the first vertebrates to evolve. Logically, this makes sense, in that the vertebral column would evolve first, with the more complex jaw bones evolving later. The early jawless fish are thought to have relied on filter feeding to capture their food, and most likely would have sucked water and debris from the seafloor into their mouth, releasing water and waste out of their gills. As other sea life evolved, these jawless fish began to feed on other fish species, and are now considered a pest in their habitat. Lampreys have no natural predators. "
both groups of jawless fish have a notochord.,(A) true (B) false,A,"Jawless fish are missing the following parts: 1. Jaws. 2. Paired fins. 3. A stomach. Characteristics they do have include: 1. A notochord, both in larvae and adults. Recall a notochord is a support rod that runs along the back of the fish. 2. Seven or more paired gill pouches. These organs take dissolved oxygen from water. 3. The branchial arches, a series of arches that support the gills of aquatic amphibians and fishes. They lie close to the bodys surface. 4. A light sensitive pineal eye, an eye-like structure that can detect light. 5. A cartilaginous skeleton, a skeleton made of a flexible rubber-like supportive material called cartilage. This is similar to the skeleton of cartilaginous fish, which includes sharks and rays. 6. A heart with two chambers. 7. Reproduction using external fertilization. 8. They are ectothermic. This means that their internal temperature depends on the temperature of their envi- ronment. "
jawless fish are missing,(A) jaws (B) paired fins (C) a stomach (D) all of the above,D,"What defines a jawless fish? You can probably guess. A jawless fish is a fish without a jaw. But there are other features that are shared by this class of organisms. Why would such an organism evolve? These fish were the first vertebrates to evolve. Logically, this makes sense, in that the vertebral column would evolve first, with the more complex jaw bones evolving later. The early jawless fish are thought to have relied on filter feeding to capture their food, and most likely would have sucked water and debris from the seafloor into their mouth, releasing water and waste out of their gills. As other sea life evolved, these jawless fish began to feed on other fish species, and are now considered a pest in their habitat. Lampreys have no natural predators. "
the skeleton of the jawless fish is made of,(A) bone (B) cartilage (C) rubber (D) bone and cartilage,B,"The earliest fish had an endoskeleton made of cartilage rather than bone. They also lacked a complete vertebral column. The first fish with a complete vertebral column evolved about 450 million years ago. These fish had jaws. They may have been similar to living sharks. About 400 million years ago, the first fish with a bony endoskeleton evolved. A bony skeleton could support a bigger body. Early bony fish evolved into modern ray-finned fish and lobe-finned fish. "
characteristics of lampreys include,(A) a huge sucker lined with teeth (B) a skull but no vertebrae (C) internal fertilization (D) all of the above,A,"There are about 28,000 living species of fish. They are placed in five different classes. The classes are commonly called hagfish, lampreys, cartilaginous fish, ray-finned fish, and lobe-finned fish. Table 13.2 shows pictures of fish in each class. It also provides additional information about the classes. Class Hagfish Lampreys Cartilaginous Fish Distinguishing Traits Hagfish are very primitive fish. They lack scales and fins. They even lack a backbone, but they do have a cranium. They secrete large amounts of thick, slimy mucus. This makes them slippery, so they can slip out of the jaws of predators. Lampreys lack scales but have fins and a partial backbone. Their mouth is surrounded by a large round sucker with teeth. They use the sucker to suck the blood of other fish. Example hagfish Cartilaginous fish include sharks, rays, and ratfish. Their endoskele- ton is made of cartilage instead of bone. They also lack a swim blad- der. However, they have a complete vertebral column and jaws. They also have a relatively big brain. shark lampreys Class Ray-Finned Fish Lobe-Finned Fish Distinguishing Traits Ray-finned fish make up the ma- jority of living fish species. They are a type of bony fish, with an en- doskeleton made of bone instead of cartilage. Their fins consist of webs of skin over flexible bony spines, called rays. They have a swim blad- der. Lobe-finned fish include only coelacanths and lungfish. They are bony fish with an endoskeleton made of bone. Their fleshy fins contain bone and muscle. Lungfish are named for a lung-like organ that they can use for breathing air. It evolved from the swim bladder. It allows them to survive for long periods of time out of water. Example puffer lungfish "
characteristics of hagfish include,(A) a huge sucker lined with teeth (B) a internal fertilization (C) a skull but no vertebrae (D) all of the above,C,"There are about 28,000 living species of fish. They are placed in five different classes. The classes are commonly called hagfish, lampreys, cartilaginous fish, ray-finned fish, and lobe-finned fish. Table 13.2 shows pictures of fish in each class. It also provides additional information about the classes. Class Hagfish Lampreys Cartilaginous Fish Distinguishing Traits Hagfish are very primitive fish. They lack scales and fins. They even lack a backbone, but they do have a cranium. They secrete large amounts of thick, slimy mucus. This makes them slippery, so they can slip out of the jaws of predators. Lampreys lack scales but have fins and a partial backbone. Their mouth is surrounded by a large round sucker with teeth. They use the sucker to suck the blood of other fish. Example hagfish Cartilaginous fish include sharks, rays, and ratfish. Their endoskele- ton is made of cartilage instead of bone. They also lack a swim blad- der. However, they have a complete vertebral column and jaws. They also have a relatively big brain. shark lampreys Class Ray-Finned Fish Lobe-Finned Fish Distinguishing Traits Ray-finned fish make up the ma- jority of living fish species. They are a type of bony fish, with an en- doskeleton made of bone instead of cartilage. Their fins consist of webs of skin over flexible bony spines, called rays. They have a swim blad- der. Lobe-finned fish include only coelacanths and lungfish. They are bony fish with an endoskeleton made of bone. Their fleshy fins contain bone and muscle. Lungfish are named for a lung-like organ that they can use for breathing air. It evolved from the swim bladder. It allows them to survive for long periods of time out of water. Example puffer lungfish "
which statement is associated with jawless fish?,(A) They have a series of branchial arches that support the gills (B) They have an eye-like structure that can detect light (C) They have at least seven pairs of gill pouches that take dissolved oxygen from water (D) All of the above are associated with jawless fish,D,"What defines a jawless fish? You can probably guess. A jawless fish is a fish without a jaw. But there are other features that are shared by this class of organisms. Why would such an organism evolve? These fish were the first vertebrates to evolve. Logically, this makes sense, in that the vertebral column would evolve first, with the more complex jaw bones evolving later. The early jawless fish are thought to have relied on filter feeding to capture their food, and most likely would have sucked water and debris from the seafloor into their mouth, releasing water and waste out of their gills. As other sea life evolved, these jawless fish began to feed on other fish species, and are now considered a pest in their habitat. Lampreys have no natural predators. "
"when the body is exercised regularly by performing weight-bearing activity, bones add bone cells to increase their bone density.",(A) true (B) false,A,"You can help keep your bones and skeletal system healthy by eating well and getting enough exercise. Weight- bearing exercises help keep bones strong. Weight-bearing exercises and activities work against gravity. Such activities include basketball, tennis, gymnastics, karate, running, and walking. When the body is exercised regularly by performing weight-bearing activity, bones respond by adding more bone cells to increase their bone density. "
bones can break in the same way a pencil breaks when bent.,(A) true (B) false,A,"Even though they are very strong, bones can fracture, or break. Fractures can happen at different places on a bone. They are usually caused by excess bending stress on the bone. Bending stress is what causes a pencil to break if you bend it too far. Soon after a fracture, the body begins to repair the break. The area becomes swollen and sore. Within a few days, bone cells travel to the break site and begin to rebuild the bone. It takes about two to three months before compact and spongy bone form at the break site. Sometimes the body needs extra help in repairing a broken bone. In such a case, a surgeon will piece a broken bone together with metal pins. Moving the broken pieces together will help keep the bone from moving and give the body a chance to repair the break. Below, a broken ulna has been repaired with pins ( Figure 1.2). The upper part of the ulna, just above the elbow joint, is broken, as you can see in the X-ray to the left. The x-ray to the right was taken after a surgeon inserted a system of pins and wires across the fracture to bring the two pieces of the ulna into close proximity. "
what are two of the most important nutrients for a healthy skeletal system?,(A) calcium and vitamin C (B) calcium and vitamin D (C) calcium and potassium (D) vitamin C and vitamin D,B,"Did you know that what you eat as a teenager can affect how healthy your skeletal system will be in 30, 40, and even 50 years? Calcium and vitamin D are two of the most important nutrients for a healthy skeletal system. Your bones need calcium to grow properly. If you do not get enough calcium in your diet as a teenager, your bones may become weak and break easily later in life. Osteoporosis is a disease in which bones lose mass and become more fragile than they should be. Osteoporosis also makes bones more likely to break. Two of the easiest ways to prevent osteoporosis are eating a healthy diet that has the right amount of calcium and vitamin D and to do some sort of weight-bearing exercise every day. Foods that are a good source of calcium include milk, yogurt, and cheese. Non-dairy sources of calcium include Chinese cabbage, kale, and broccoli. Many fruit juices, fruit drinks, tofu, and cereals have calcium added to them. It is recommended that teenagers get 1300 mg of calcium every day. For example, one cup (8 fl. oz.) of milk provides about 300 mg of calcium, or about 30% of the daily requirement. Other sources of calcium are pictured in the Figure 1.1. There are many different sources of cal- cium. Getting enough calcium in your daily diet is important for good bone health. Vitamin D is unusual since you dont have to rely on your diet alone to get enough of this vitamin. Your skin makes vitamin D when exposed to sunlight. Pigments in the skin act like a filter that can prevent the skin from making vitamin D. As a result, people with darker skin need more time in the sun than people with lighter skin to make the same amount of vitamin D. You can also get vitamin D from foods. Fish is naturally rich in vitamin D. In the United States, vitamin D is added to other foods, including milk, soy milk, and breakfast cereals. Teenagers are recommended to get 5 micrograms (200 IU) of vitamin D every day. A 3 12 -ounce portion of cooked salmon provides 360 IU of vitamin D. A 8-ounce glass of milk is fortified with about 100 IU of vitamin D. "
what is the first step in the repair of a bone fracture?,(A) blood cells begin to rebuild the cartilage (B) so bone can form (C) b bone cells travel to the break site and begin to rebuild the bone (D) c compact and spongy bone form at the break site (E) d spongy bone forms around compact bone at the break site,B,"Even though they are very strong, bones can fracture, or break. Fractures can happen at different places on a bone. They are usually caused by excess bending stress on the bone. Bending stress is what causes a pencil to break if you bend it too far. Soon after a fracture, the body begins to repair the break. The area becomes swollen and sore. Within a few days, bone cells travel to the break site and begin to rebuild the bone. It takes about two to three months before compact and spongy bone form at the break site. Sometimes the body needs extra help in repairing a broken bone. In such a case, a surgeon will piece a broken bone together with metal pins. Moving the broken pieces together will help keep the bone from moving and give the body a chance to repair the break. Below, a broken ulna has been repaired with pins ( Figure 1.2). The upper part of the ulna, just above the elbow joint, is broken, as you can see in the X-ray to the left. The x-ray to the right was taken after a surgeon inserted a system of pins and wires across the fracture to bring the two pieces of the ulna into close proximity. "
osteoporosis causes,(A) ligaments to tear (B) cartilage to break down (C) bones to lose mass and become fragile (D) bones to stop growing and break,C,"Osteoporosis is a disease in which the bones become porous and weak because they do not contain enough calcium. The graph in Figure 16.14 shows how the mass of calcium in bone peaks around age 30 and declines after that, especially in women. Maximizing the calcium in your bones while youre young will reduce your risk of developing osteoporosis later in of life. "
teenagers need about _________ of calcium daily.,(A) 1300 grams (B) 1300 mg (C) 130 mg (D) 1300 kg,B,"Did you know that what you eat as a teenager can affect how healthy your skeletal system will be in 30, 40, and even 50 years? Calcium and vitamin D are two of the most important nutrients for a healthy skeletal system. Your bones need calcium to grow properly. If you do not get enough calcium in your diet as a teenager, your bones may become weak and break easily later in life. Osteoporosis is a disease in which bones lose mass and become more fragile than they should be. Osteoporosis also makes bones more likely to break. Two of the easiest ways to prevent osteoporosis are eating a healthy diet that has the right amount of calcium and vitamin D and to do some sort of weight-bearing exercise every day. Foods that are a good source of calcium include milk, yogurt, and cheese. Non-dairy sources of calcium include Chinese cabbage, kale, and broccoli. Many fruit juices, fruit drinks, tofu, and cereals have calcium added to them. It is recommended that teenagers get 1300 mg of calcium every day. For example, one cup (8 fl. oz.) of milk provides about 300 mg of calcium, or about 30% of the daily requirement. Other sources of calcium are pictured in the Figure 1.1. There are many different sources of cal- cium. Getting enough calcium in your daily diet is important for good bone health. Vitamin D is unusual since you dont have to rely on your diet alone to get enough of this vitamin. Your skin makes vitamin D when exposed to sunlight. Pigments in the skin act like a filter that can prevent the skin from making vitamin D. As a result, people with darker skin need more time in the sun than people with lighter skin to make the same amount of vitamin D. You can also get vitamin D from foods. Fish is naturally rich in vitamin D. In the United States, vitamin D is added to other foods, including milk, soy milk, and breakfast cereals. Teenagers are recommended to get 5 micrograms (200 IU) of vitamin D every day. A 3 12 -ounce portion of cooked salmon provides 360 IU of vitamin D. A 8-ounce glass of milk is fortified with about 100 IU of vitamin D. "
activities that increase bone strength include,(A) weight lifting (B) walking (C) karate (D) all of the above,D,"You can help keep your bones and skeletal system healthy by eating well and getting enough exercise. Weight- bearing exercises help keep bones strong. Weight-bearing exercises and activities work against gravity. Such activities include basketball, tennis, gymnastics, karate, running, and walking. When the body is exercised regularly by performing weight-bearing activity, bones respond by adding more bone cells to increase their bone density. "
your skin constantly protects you from infections.,(A) true (B) false,A,"Your skin is your largest organ and constantly protects you from infections, so keeping your skin healthy is a good idea. "
"your skin makes vitamins, like vitamins a, b, c and d.",(A) true (B) false,B,"Your skin is your largest organ and constantly protects you from infections, so keeping your skin healthy is a good idea. "
about what percent of skin cancers are linked to sun exposure?,(A) 50% (B) 75% (C) 90% (D) 100%,C,"Some sunlight is good for your health. Vitamin D is made in the skin when it is exposed to sunlight. But getting too much sun can be unhealthy. A sunburn is a burn to the skin that is caused by overexposure to UV radiation from the suns rays or tanning beds. Light-skinned people, like the man pictured below ( Figure 1.1), get sunburned more quickly than people with darker skin. This is because pigments (melanin) in the skin act as a natural sunblock that help to protect the body from UV radiation. With over one million new cases each year, skin cancer, which is cancer that forms in the tissues of the skin, is the most common form of human cancer. Children and teens who have been sunburned are at a greater risk of developing skin cancer later in life. Long-term exposure to UV radiation is the leading cause of skin cancer. About 90 percent of skin cancers are linked to sun exposure. UV radiation damages the genetic material (DNA) of skin cells. This damage can cause the skin cells to grow out of control and form a tumor. Some of these tumors are very difficult to cure. For this reason you should always wear sunscreen with a high sun protection factor (SPF), a hat, and clothing when out in the sun. Sunburn is caused by overexposure to UV rays. Getting sunburned as a child or a teen, especially sunburn that causes blistering, increases the risk of developing skin cancer later in life. "
herpes simplex virus type 1 causes,(A) acne (B) cold sores (C) canker sores (D) all of the above,B,"Genital warts are an STI caused by human papilloma virus, or HPV. They are one of the most common STIs in teenagers. HPV infections cannot be cured. But a new vaccine called Gardasil can prevent most HPV infections in females. Many doctors recommend that females between the ages of 9 and 26 years receive the vaccine. Preventing HPV infections in females is important because HPV can also cause cancer of the cervix. A related herpes virus causes cold sores on the lips ( Figure 1.2). Both viruses cause painful blisters. In the case of genital herpes, the blisters are on the penis or around the vaginal opening. The blisters go away on their own, but the virus remains in the body. The blisters may come back repeatedly, especially when a person is under stress. There is no cure for genital herpes. But drugs can help prevent or shorten outbreaks. Researchers are trying to find a vaccine to prevent genital herpes. Hepatitis B is a disease of the liver. It is caused by a virus called hepatitis B, which can be passed through sexual activity. Hepatitis B causes vomiting. It also causes yellowing of the skin and eyes. The disease goes away on its own in some people. Other people are sick for the rest of their lives. In these people, the virus usually damages the liver. It may also lead to liver cancer. Medicines can help prevent liver damage in these people. There is also a vaccine to protect against hepatitis B. HIV stands for ""human immunodeficiency virus."" It is the virus that causes AIDS. HIV and AIDS are described in a previous concept. HIV can spread through sexual contact. It can also spread through body fluids such as blood. There is no cure for HIV infection, and AIDS can cause death, although AIDS can be delayed for several years with medication. Researchers are trying to find a vaccine to prevent HIV infection. "
causes of canker sores include,(A) stress (B) food allergies (C) mouth injury (D) All of the above are causes of canker sores,D,"Conditions that irritate, clog or inflame your skin can cause symptoms such as redness, swelling, burning and itching. Allergies, irritants, your genetic background and certain diseases and immune system problems can cause numerous skin conditions. Many skin problems, such as acne, also affect your appearance. Acne Your skin has tiny holes called pores that that can become blocked by oil, bacteria, dead skin and dirt. When this occurs, you may develop a pimple. Acne is a skin condition that causes pimples, and is one of the more common skin problem among teenagers. A diet high in refined sugars or carbohydrates such as bread and chips can also lead to acne. Each pore on your skin is the opening to a follicle, which is made of a hair and sebaceous gland that releases sebum. Acne may result from too much sebum produced by the follicle, dead skin cells accumulating in the pore, or bacteria built up in the pore. Cleaning your skin daily with a mild soap to remove excess oil and dirt can help prevent acne. Cold Sores Cold sores are red, fluid-filled blisters that appear near the mouth or on other areas of the face, usually caused by herpes simplex virus type 1. Visible sores are contagious, but herpes may be spread even when sores cant be seen. You can catch the herpes simplex virus through kissing, sharing cosmetics, or sharing food with infected individuals. Once you catch herpes simplex virus, it cant be cured. Even after sores have healed, the virus remains in your body, and new cold sores can appear at any time. This is not to be confused with genital herpes, which is caused by herpes simplex virus type 2. Canker Sore A canker sore is a mouth ulcer or sore that is open and painful. They may be on the lips or inside of the lip or cheek. Canker sores are usually white or yellowish, surrounded by red, inflamed soft tissue. A canker sore can be either a simple canker or a complex canker. A simple canker sore reemerges about three to four times every year, and is the common type in people between the ages of 10 and 20. Canker sores are not contagious and usually heal on their own within a week or two. Causes of canker sores include a viral infection, stress, hormonal fluctuations, food allergies, immune system problems, or mouth injuries. "
which of the following is the best description of the cause of body odor?,(A) an excessive growth of bacteria on the skin (B) excessive sweating (C) not bathing every day (D) dirty clothes,A,"Keeping your skin clean is important because dirty skin is more prone to infection. Bathing every day helps to keep your skin clean and healthy. Also, you know that taking a bath or shower helps prevent body odor. But where does body odor come from? During the day, sweat, oil, dirt, dust, and dead skin cells can build up on the skin surface. If not washed away, the mix of these materials can encourage the excess growth of bacteria. These bacteria feed on these substances and cause a smell that is commonly called body odor. "
which of the following can lead to acne?,(A) too much sebum (B) dead skin cells in your skin pores (C) the build up of bacteria in your skin pores (D) All of the above can lead to acne,D,"What can you do to keep your skin healthy? The most important step you can take is to protect your skin from sun exposure. On sunny days, wear long sleeves and pants and a hat with a brim. Also apply sunscreen to exposed areas of skin. Protecting your skin in these ways will reduce damage to your skin by ultraviolet light. This is important because skin that has been damaged by ultraviolet light is at greater risk of developing skin cancer. This is true whether the damage is due to sunlight or the light in tanning beds. About 85 percent of teens develop acne, like the boy in Figure 16.9. Acne is a condition in which pimples form on the skin. It is caused by a bacterial infection. It happens when the sebaceous glands secrete too much sebum. The excess oil provides a good place for bacteria to grow. Keeping the skin clean helps prevent acne. Over-the-counter products or prescription drugs may be needed if the problem is serious or doesnt clear up on its own. "
your brain needs to be exercised to stay healthy.,(A) true (B) false,A,"The nervous system is such an important part of your body. You want it to work at its best so that you can be at your best. Your nervous system contains what is probably the most important part of your body, which, of course, is your brain. Your brain allows you to learn. It allows you to feel emotions like love, anger, and sadness. Your brain gives you the ability to see, hear, taste, touch, and smell. It works together with the nerves and spinal cord to send the signals that make your body move. Your nervous system lets you do things like run, jump, play sports, and do your homework. There are many choices you can make to keep your nervous system healthy. One obvious choice is to avoid using alcohol or other drugs. Not only will you avoid the injury that drugs themselves can cause, but you will also be less likely to get involved in other risky behaviors that could harm your nervous system. Another way to keep the nervous system healthy is to eat a variety of healthy foods. The minerals sodium, calcium, and potassium, and vitamins B1 and B12 are important for a healthy nervous system. Some foods that are good sources for these minerals and vitamins include milk, whole grains, beef steak, and kidney beans (shown in Figure 1.1). Your brain also needs healthy fats like those in nuts and fish. Recall that fats insulate the axons of neurons. These fats help build new connections between nerves and brain cells. These fats may improve memory and increase learning and intelligence. Water is also important for the nervous system, so drink plenty of water and other fluids. This helps prevent dehydration, which can cause confusion and memory problems. And get plenty of rest. Your brain requires plenty of rest so it can strengthen circuits that help with memory. A good nights sleep will help keep your brain functioning at its best. These foods are sources of nutrients needed for a healthy nervous system. Daily physical activity is also important for nervous system health. Regular exercise makes your heart more efficient at pumping blood to your brain. As a result, your brain gets more oxygen, which it needs to function normally. The saying use it or lose it applies to your brain as well as your body. This means that mental activity, not just physical activity, is important for nervous system health. Doing crossword puzzles, reading, and playing a musical instrument are just a few ways you can keep your brain active. You can also choose to practice safe behaviors to protect your nervous system from injury. To keep your nervous system safe, choose to: Bicycle helmets help protect from head injuries. Making healthy choices like this can help prevent nervous system injuries that could cause lifelong disability. Furthermore, make sure to exercise your nervous system on a daily basis. The simple act of writing requires that you use all the major components of your motor and sensory pathways. These include a number of different sensory receptors, peripheral nerves, synaptic connections within your spinal cord, major tracts within your spinal cord, and nerve tissue throughout your brain. All these components need to be utilized with great precision and coordination to produce neatly written words. What should you do? Spend a few minutes each day writing on paper as neatly as you can. This takes a lot more effort on the part of the nervous system than typing on a keyboard, as typing on a keyboard doesnt require as much fine motor control as writing on paper. If you dont want to write, then draw. Drawing with precision also requires use of all the major components of the sensory and motor divisions of the nervous system. "
there are fats that are good for your brain.,(A) true (B) false,A,"Lipids are nutrients, such as fats that store energy. Lipids also have several other roles in the body. For example, lipids protect nerves and make up the membranes that surround cells. Fats are one type of lipid. Stored fat gives your body energy to use for later. Its like having money in a savings account: its there in case you need it. Stored fat also cushions and protects internal organs. In addition, it insulates the body. It helps keep you warm in cold weather. Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. Seafood and eggs are other good sources of protein. There are two main types of fats, saturated and unsaturated. 1. Saturated fats can be unhealthy, even in very small amounts. They are found mainly in animal foods, such as meats, whole milk, and eggs. So even though these foods are good sources of proteins, they should be eaten in limited amounts. Saturated lipids increase cholesterol levels in the blood. Too much cholesterol in the blood Another type of lipid is called trans fat. Trans fats are manufactured and added to certain foods to keep them fresher for longer. Foods that contain trans fats include cakes, cookies, fried foods, and margarine. Eating foods that contain trans fats increases the risk of heart disease. Beginning with Denmark in 2003, many nations now limit the amount of trans fat that can be in food products or ban these products all together. On January 1, 2008, Calgary became the first city in Canada to ban trans fats from restaurants and fast food chains. Beginning in 2010, California banned trans fats from restaurant products, and in 2011, from all retail baked goods. "
what is the role of fats in the nervous system?,(A) Some fats improve memory and increase learning and intelligence (B) Fats help build new connections between nerves and brain cells (C) Fats cover the axons of neurons (D) all of the above,D,"Lipids are nutrients, such as fats that store energy. Lipids also have several other roles in the body. For example, lipids protect nerves and make up the membranes that surround cells. Fats are one type of lipid. Stored fat gives your body energy to use for later. Its like having money in a savings account: its there in case you need it. Stored fat also cushions and protects internal organs. In addition, it insulates the body. It helps keep you warm in cold weather. Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. Seafood and eggs are other good sources of protein. There are two main types of fats, saturated and unsaturated. 1. Saturated fats can be unhealthy, even in very small amounts. They are found mainly in animal foods, such as meats, whole milk, and eggs. So even though these foods are good sources of proteins, they should be eaten in limited amounts. Saturated lipids increase cholesterol levels in the blood. Too much cholesterol in the blood Another type of lipid is called trans fat. Trans fats are manufactured and added to certain foods to keep them fresher for longer. Foods that contain trans fats include cakes, cookies, fried foods, and margarine. Eating foods that contain trans fats increases the risk of heart disease. Beginning with Denmark in 2003, many nations now limit the amount of trans fat that can be in food products or ban these products all together. On January 1, 2008, Calgary became the first city in Canada to ban trans fats from restaurants and fast food chains. Beginning in 2010, California banned trans fats from restaurant products, and in 2011, from all retail baked goods. "
ways to keep your nervous system safe include,(A) wearing safety goggles or sunglasses to protect your eyes from injury (B) wearing ear plugs to protect your ears from soft sounds (C) wearing a safety helmet for activities like running and biking (D) all of the above,A,"The nervous system is such an important part of your body. You want it to work at its best so that you can be at your best. Your nervous system contains what is probably the most important part of your body, which, of course, is your brain. Your brain allows you to learn. It allows you to feel emotions like love, anger, and sadness. Your brain gives you the ability to see, hear, taste, touch, and smell. It works together with the nerves and spinal cord to send the signals that make your body move. Your nervous system lets you do things like run, jump, play sports, and do your homework. There are many choices you can make to keep your nervous system healthy. One obvious choice is to avoid using alcohol or other drugs. Not only will you avoid the injury that drugs themselves can cause, but you will also be less likely to get involved in other risky behaviors that could harm your nervous system. Another way to keep the nervous system healthy is to eat a variety of healthy foods. The minerals sodium, calcium, and potassium, and vitamins B1 and B12 are important for a healthy nervous system. Some foods that are good sources for these minerals and vitamins include milk, whole grains, beef steak, and kidney beans (shown in Figure 1.1). Your brain also needs healthy fats like those in nuts and fish. Recall that fats insulate the axons of neurons. These fats help build new connections between nerves and brain cells. These fats may improve memory and increase learning and intelligence. Water is also important for the nervous system, so drink plenty of water and other fluids. This helps prevent dehydration, which can cause confusion and memory problems. And get plenty of rest. Your brain requires plenty of rest so it can strengthen circuits that help with memory. A good nights sleep will help keep your brain functioning at its best. These foods are sources of nutrients needed for a healthy nervous system. Daily physical activity is also important for nervous system health. Regular exercise makes your heart more efficient at pumping blood to your brain. As a result, your brain gets more oxygen, which it needs to function normally. The saying use it or lose it applies to your brain as well as your body. This means that mental activity, not just physical activity, is important for nervous system health. Doing crossword puzzles, reading, and playing a musical instrument are just a few ways you can keep your brain active. You can also choose to practice safe behaviors to protect your nervous system from injury. To keep your nervous system safe, choose to: Bicycle helmets help protect from head injuries. Making healthy choices like this can help prevent nervous system injuries that could cause lifelong disability. Furthermore, make sure to exercise your nervous system on a daily basis. The simple act of writing requires that you use all the major components of your motor and sensory pathways. These include a number of different sensory receptors, peripheral nerves, synaptic connections within your spinal cord, major tracts within your spinal cord, and nerve tissue throughout your brain. All these components need to be utilized with great precision and coordination to produce neatly written words. What should you do? Spend a few minutes each day writing on paper as neatly as you can. This takes a lot more effort on the part of the nervous system than typing on a keyboard, as typing on a keyboard doesnt require as much fine motor control as writing on paper. If you dont want to write, then draw. Drawing with precision also requires use of all the major components of the sensory and motor divisions of the nervous system. "
your brain needs water to,(A) to fix broken connections (B) to allow nerves to travel (C) to prevent dehydration (D) all of the above,C,"Water is essential to life because chemical reactions within cells take place in water. Most people can survive only a few days without consuming water to replace their water losses. How do you lose water? You lose water in your breath each time you exhale. You lose water in urine. You lose water in sweat, especially if you are active in warm weather. The boy in Figure 17.5 is taking a water break while playing outside on a hot day. If he doesnt take in enough water to replace the water lost in sweat, he may become dehydrated. Symptoms of dehydration include dry mouth, headache, and dizziness. Dehydration can be very serious. It can even cause death. "
your brain needs to rest,(A) to regenerate nerves (B) to strengthen circuits that help with memory (C) to stop use for a period of time (D) all of the above,B,"The nervous system is such an important part of your body. You want it to work at its best so that you can be at your best. Your nervous system contains what is probably the most important part of your body, which, of course, is your brain. Your brain allows you to learn. It allows you to feel emotions like love, anger, and sadness. Your brain gives you the ability to see, hear, taste, touch, and smell. It works together with the nerves and spinal cord to send the signals that make your body move. Your nervous system lets you do things like run, jump, play sports, and do your homework. There are many choices you can make to keep your nervous system healthy. One obvious choice is to avoid using alcohol or other drugs. Not only will you avoid the injury that drugs themselves can cause, but you will also be less likely to get involved in other risky behaviors that could harm your nervous system. Another way to keep the nervous system healthy is to eat a variety of healthy foods. The minerals sodium, calcium, and potassium, and vitamins B1 and B12 are important for a healthy nervous system. Some foods that are good sources for these minerals and vitamins include milk, whole grains, beef steak, and kidney beans (shown in Figure 1.1). Your brain also needs healthy fats like those in nuts and fish. Recall that fats insulate the axons of neurons. These fats help build new connections between nerves and brain cells. These fats may improve memory and increase learning and intelligence. Water is also important for the nervous system, so drink plenty of water and other fluids. This helps prevent dehydration, which can cause confusion and memory problems. And get plenty of rest. Your brain requires plenty of rest so it can strengthen circuits that help with memory. A good nights sleep will help keep your brain functioning at its best. These foods are sources of nutrients needed for a healthy nervous system. Daily physical activity is also important for nervous system health. Regular exercise makes your heart more efficient at pumping blood to your brain. As a result, your brain gets more oxygen, which it needs to function normally. The saying use it or lose it applies to your brain as well as your body. This means that mental activity, not just physical activity, is important for nervous system health. Doing crossword puzzles, reading, and playing a musical instrument are just a few ways you can keep your brain active. You can also choose to practice safe behaviors to protect your nervous system from injury. To keep your nervous system safe, choose to: Bicycle helmets help protect from head injuries. Making healthy choices like this can help prevent nervous system injuries that could cause lifelong disability. Furthermore, make sure to exercise your nervous system on a daily basis. The simple act of writing requires that you use all the major components of your motor and sensory pathways. These include a number of different sensory receptors, peripheral nerves, synaptic connections within your spinal cord, major tracts within your spinal cord, and nerve tissue throughout your brain. All these components need to be utilized with great precision and coordination to produce neatly written words. What should you do? Spend a few minutes each day writing on paper as neatly as you can. This takes a lot more effort on the part of the nervous system than typing on a keyboard, as typing on a keyboard doesnt require as much fine motor control as writing on paper. If you dont want to write, then draw. Drawing with precision also requires use of all the major components of the sensory and motor divisions of the nervous system. "
foods that are good for the brain include,(A) milk and whole grains (B) nuts and fish (C) steak and beans (D) all of the above,D,"Make at least half your daily grain choices whole grains. Examples of whole grains are whole wheat bread, whole wheat pasta, and brown rice. Choose a variety of different vegetables each day. Be sure to include both dark green vegetables, such as spinach and broccoli, and orange vegetables, such as carrots and sweet potatoes. Choose a variety of different fruits each day. Select mainly fresh fruits rather than canned fruits, and whole fruits instead of fruit juices. When choosing oils, choose unsaturated oils, such as olive oil, canola oil, or vegetable oil. Choose low-fat or fat-free milk and other dairy products. For example, select fat-free yogurt and low-fat cheese. For meats, choose fish, chicken, and lean cuts of beef. Also, be sure to include beans, nuts, and seeds. "
"each kidney has up to 1,000 individual filtering units.",(A) true (B) false,B,"The kidneys are a pair of bean-shaped organs at each side of the body just above the waist. You can see a diagram of a kidney in Figure 19.7. The function of the kidneys is to filter blood and form urine. Tiny structures in the kidneys, called nephrons, perform this function. Each kidney contains more than a million nephrons. "
the kidneys only work when you are awake.,(A) true (B) false,B,"You need only one kidney to live a normal, healthy life. A single kidney can do all the work of filtering the blood and maintaining homeostasis. However, at least one kidney must function properly to maintain life. Diseases that threaten the health and functioning of the kidneys include kidney stones, infections, and diabetes. You can learn more about kidney diseases in this video:  . MEDIA Click image to the left or use the URL below. URL:  Kidney stones are mineral crystals that form in urine inside a kidney, as shown in Figure 19.8. The stones may be extremely painful. If a kidney stone blocks a ureter, it must be removed so urine can leave the kidney and be excreted. Bacterial infections of urinary organs, especially the urinary bladder, are common. They are called urinary tract infections. Generally, they can be cured with antibiotic drugs. However, if they arent treated, they can lead to more serious infections and damage to the kidneys. Untreated diabetes may damage capillaries in the kidneys so the nephrons can no longer filter blood. This is called kidney failure. The only cure for kidney failure is to receive a healthy transplanted kidney from a donor. Until that happens, a patient with kidney failure can be kept alive by artificially filtering the blood through a machine. This is called hemodialysis. You can see how it works in Figure 19.9. "
what is the first step in urine formation?,(A) Blood flows into the kidney through the urethra (B) Blood flows into the kidney through the renal vein (C) Blood flows into the kidney through the renal artery (D) Blood flows into the kidney through the nephron,C,"The process of urine formation is as follows: 1. Blood flows into the kidney through the renal artery. The renal artery connects to capillaries inside the kidney. Capillaries and nephrons lie very close to each other in the kidney. 2. The blood pressure within the capillaries causes water, salts, sugars, and urea to leave the capillaries and move into the nephron. 3. The water and salts move along through the tube-shaped nephron to a lower part of the nephron. 4. The fluid that remains in the nephron at this point is called urine. 5. The blood that leaves the kidney in the renal vein has much less waste than the blood that entered the kidney. 6. The urine is collected in the ureters and is moved to the urinary bladder, where it is stored. Nephrons filter about 14 cup of body fluid per minute. In a 24-hour period, nephrons filter 180 liters of fluid, and 1.5 liters of the fluid is released as urine. Urine enters the bladder through the ureters. Similar to a balloon, the walls of the bladder are stretchy. The stretchy walls allow the bladder to hold a large amount of urine. The bladder can hold about 1 12 to 2 21 cups of urine but may also hold more if the urine cannot be released immediately. How do you know when you have to urinate? Urination is the process of releasing urine from the body. Urine leaves the body through the urethra. Nerves in the bladder tell you when it is time to urinate. As the bladder first fills with urine, you may notice a feeling that you need to urinate. The urge to urinate becomes stronger as the bladder continues to fill up. The location of nephrons in the kidney. The fluid collects in the nephron tubules and moves to the bladder through the ureter. "
what is the functional unit of the kidney?,(A) the urethra (B) the nephron (C) the renal gland (D) the kidney gland,B,"The kidneys are a pair of bean-shaped organs at each side of the body just above the waist. You can see a diagram of a kidney in Figure 19.7. The function of the kidneys is to filter blood and form urine. Tiny structures in the kidneys, called nephrons, perform this function. Each kidney contains more than a million nephrons. "
which best describes the blood that leaves the kidney?,(A) The blood that leaves the kidney has much less waste than the blood that (B) The blood that leaves the kidney has much less oxygen than the blood that entered the kidney (C) The blood that leaves the kidney has much less carbon dioxide than the blood that entered the kidney (D) all of the above,A,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
what leaves the capillaries during the filtration process?,(A) blood (B) oxygen (C) water (D) salts (E) sugars (F) and urea (G) d all of the above,C,"Blood with wastes enters each kidney through an artery, which branches into many capillaries. After passing through capillaries and being filtered, the clean blood leaves the kidney through a vein. The part of each nephron called the glomerulus is where blood in the capillaries is filtered. Excess water and wastes are filtered out of the blood. The tubule of the nephron collects these substances. Some of the water is reabsorbed. The remaining fluid is urine. "
"each day, how much fluid is filtered by the kidneys?",(A) 18 liters (B) 180 liters (C) 1 (D) 800 liters (E) d 180 (F) 000 liters,C,"The process of urine formation is as follows: 1. Blood flows into the kidney through the renal artery. The renal artery connects to capillaries inside the kidney. Capillaries and nephrons lie very close to each other in the kidney. 2. The blood pressure within the capillaries causes water, salts, sugars, and urea to leave the capillaries and move into the nephron. 3. The water and salts move along through the tube-shaped nephron to a lower part of the nephron. 4. The fluid that remains in the nephron at this point is called urine. 5. The blood that leaves the kidney in the renal vein has much less waste than the blood that entered the kidney. 6. The urine is collected in the ureters and is moved to the urinary bladder, where it is stored. Nephrons filter about 14 cup of body fluid per minute. In a 24-hour period, nephrons filter 180 liters of fluid, and 1.5 liters of the fluid is released as urine. Urine enters the bladder through the ureters. Similar to a balloon, the walls of the bladder are stretchy. The stretchy walls allow the bladder to hold a large amount of urine. The bladder can hold about 1 12 to 2 21 cups of urine but may also hold more if the urine cannot be released immediately. How do you know when you have to urinate? Urination is the process of releasing urine from the body. Urine leaves the body through the urethra. Nerves in the bladder tell you when it is time to urinate. As the bladder first fills with urine, you may notice a feeling that you need to urinate. The urge to urinate becomes stronger as the bladder continues to fill up. The location of nephrons in the kidney. The fluid collects in the nephron tubules and moves to the bladder through the ureter. "
chloroplasts are one of the main differences between plant and animal cells.,(A) true (B) false,A,"A third difference between plant and animal cells is that plants have several kinds of organelles called plastids. And there are several different kinds of plastids in plant cells. For example, Chloroplasts are needed for photosynthesis, leucoplasts can store starch or oil, and brightly colored chromoplasts give some flowers and fruits their yellow, orange, or red color. It is the presence of chloroplasts and the ability to photosynthesize, that is one of the defining features of a plant. No animal or fungi can photosynthesize, and only some protists are able to. The photosynthetic protists are the plant-like protists, represented mainly by the unicellular algae. "
photosynthesis can only occur during daylight hours.,(A) true (B) false,A,"Photosynthesis begins with the light reactions. It is during these reactions that the energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membranes of the chloroplast. The energy is then temporarily transferred to two molecules, ATP and NADPH, which are used in the second stage of photosynthesis. ATP and NADPH are generated by two electron transport chains. During the light reactions, water is used and oxygen is produced. These reactions can only occur during daylight as the process needs sunlight to begin. "
what molecules are necessary to begin photosynthesis?,(A) carbon dioxide and oxygen (B) carbon dioxide and water (C) glucose and oxygen (D) glucose and water,B,"What goes into the plant cell to start photosynthesis? The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the suns energy are necessary for photosynthesis to occur. These three components must meet in the chloroplast of the leaf cell for photosynthesis to occur. How do these three components get to the cells in the leaf? Chlorophyll is the green pigment in leaves that captures energy from the sun. Chlorophyll molecules are located in the thylakoid membranes inside chloroplasts. The veins in a plant carry water from the roots to the leaves. Carbon dioxide enters the leaf from the air through special openings called stomata ( Figure 1.2). "
which best describes chlorophyll?,(A) Chlorophyll carries water from the roots to the leaves (B) Carbon dioxide enters the leaf through chlorophyll (C) Chlorophyll is the green pigment in leaves that captures energy from the sun (D) Chlorophyll is the site of photosynthesis in the leaf cell,C,"As part of the hydrologic cycle, water spends a lot of time in the atmosphere, mostly as water vapor. The atmosphere is an important reservoir for water. Chlorophyll indicates the presence of photosynthesizing plants as does the veg- etation index. "
which of the following does not occur during the light reactions?,(A) Energy is transferred to ATP and NADPH (B) Energy from sunlight is absorbed (C) Glucose is produced from carbon dioxide (D) Water is used and oxygen is produced,C,"The light reactions occur in the first stage of photosynthesis. This stage takes place in the thylakoid membranes of the chloroplast. In the light reactions, energy from sunlight is absorbed by chlorophyll. This energy is temporarily transferred to two molecules: ATP and NADPH. These molecules are used to store the energy for the second stage of photosynthesis. The light reactions use water and produce oxygen. "
what is the waste product of the photosynthesis process?,(A) glucose (B) carbon dioxide (C) water (D) oxygen,D,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
which of the following is true concerning glucose?,(A) Glucose can be considered the “food” of plants (B) Glucose is a simple sugar molecule (C) Glucose can be used to store energy in large molecules (D) such as starch (E) d All of the above are true concerning glucose,D,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
limiting factors to population growth raise death rates.,(A) true (B) false,A,"For a population to be healthy, factors such as food, nutrients, water and space, must be available. What happens when there are not resources to support the population? Limiting factors are resources or other factors in the environment that can lower the population growth rate. Limiting factors include a low food supply and lack of space. Limiting factors can lower birth rates, increase death rates, or lead to emigration. When organisms face limiting factors, they show logistic growth (S-shaped curve, curve B: Figure 1.1). Compe- tition for resources like food and space cause the growth rate to stop increasing, so the population levels off. This flat upper line on a growth curve is the carrying capacity. The carrying capacity (K) is the maximum population size that can be supported in a particular area without destroying the habitat. Limiting factors determine the carrying capacity of a population. Recall that when there are no limiting factors, the population grows exponentially. In exponential growth (J-shaped curve, curve A: Figure 1.1), as the population size increases, the growth rate also increases. Exponential and Logistic Growth. Curve A shows exponential growth. shows logistic growth. Curve B Notice that the carrying capacity (K) is also shown. "
"as the population increases, resource availability decreases.",(A) true (B) false,A,"Every 20 minutes, the human population adds 3,500 more people. More people need more resources. For example, we now use five times more fossil fuels than we did in 1970. The human population is expected to increase for at least 40 years. What will happen to resource use? "
"when graphed, exponential growth looks like a",(A) I-shaped curve (B) S-shaped curve (C) J-shaped curve (D) X-shaped curve,C,"Population growth can be described with two models, based on the size of the population and necessary resources. These two types of growth are known as exponential growth and logistic growth. If a population is given unlimited amounts of resources, such as food and water, land if needed, moisture, oxygen, and other environmental factors, it will grow exponentially. Exponential growth occurs as a population grows larger, dramatically increasing the growth rate. This is shown as a ""J-shaped"" curve below ( Figure 1.3). You can see that the population grows slowly at first, but as time passes, growth occurs more and more rapidly. Growth of populations according to ex- ponential (or J-curve) growth model (left) and logistic (or S-curve) growth model (right). Time is plotted on the x-axis, and population size is plotted on the y-axis. In nature, organisms do not usually have ideal environments with unlimited food. In nature, there are limits. Sometimes, there will be plenty of food. Sometimes, a fire will wipe out all of the available nutrients. Sometimes a predator will kill many individuals in a population. How do you think these limits affect the way organisms grow? "
"when organisms face limiting factors,",(A) they have exponential growth (B) they have logistic growth (C) they have carrying capacity growth (D) they have stable growth,B,"Every stable population has one or more factors that limit its growth. A limiting factor determines the carrying capacity for a species. A limiting factor can be any biotic or abiotic factor: nutrient, space, and water availability are examples (Figure 1.1). The size of a population is tied to its limiting factor. What happens if a limiting factor increases a lot? Is it still a limiting factor? If a limiting factor increases a lot, another factor will most likely become the new limiting factor. This may be a bit confusing, so lets look at an example of limiting factors. Say you want to make as many chocolate chip cookies as you can with the ingredients you have on hand. It turns out that you have plenty of flour and other ingredients, but only two eggs. You can make only one batch of cookies, because eggs are the limiting factor. But then your neighbor comes over with a dozen eggs. Now you have enough eggs for seven batches of cookies, but only two pounds of butter. You can make four batches of cookies, with butter as the limiting factor. If you get more butter, some other ingredient will be limiting. Species ordinarily produce more offspring than their habitat can support (Figure 1.2). If conditions improve, more young survive and the population grows. If conditions worsen, or if too many young are born, there is competition between individuals. As in any competition, there are some winners and some losers. Those individuals that survive to fill the available spots in the niche are those that are the most fit for their habitat. Click image to the left or use the URL below. URL:  A frog in frog spawn. An animal produces many more offspring than will survive. "
"when organisms face limiting factors,",(A) the death rate increases (B) the birth rate decreases (C) they have increased migration (D) all of the above,D,"Every stable population has one or more factors that limit its growth. A limiting factor determines the carrying capacity for a species. A limiting factor can be any biotic or abiotic factor: nutrient, space, and water availability are examples (Figure 1.1). The size of a population is tied to its limiting factor. What happens if a limiting factor increases a lot? Is it still a limiting factor? If a limiting factor increases a lot, another factor will most likely become the new limiting factor. This may be a bit confusing, so lets look at an example of limiting factors. Say you want to make as many chocolate chip cookies as you can with the ingredients you have on hand. It turns out that you have plenty of flour and other ingredients, but only two eggs. You can make only one batch of cookies, because eggs are the limiting factor. But then your neighbor comes over with a dozen eggs. Now you have enough eggs for seven batches of cookies, but only two pounds of butter. You can make four batches of cookies, with butter as the limiting factor. If you get more butter, some other ingredient will be limiting. Species ordinarily produce more offspring than their habitat can support (Figure 1.2). If conditions improve, more young survive and the population grows. If conditions worsen, or if too many young are born, there is competition between individuals. As in any competition, there are some winners and some losers. Those individuals that survive to fill the available spots in the niche are those that are the most fit for their habitat. Click image to the left or use the URL below. URL:  A frog in frog spawn. An animal produces many more offspring than will survive. "
a small population will most likely,(A) have exponential growth (B) have plenty of food to eat (C) have plenty of space to live (D) all of the above,D,"Population size is the number of individuals in a population. Population size influences the chances of a species surviving or going extinct. If a species populations become very small, the species may be at risk of going extinct. "
carrying capacity is reached,(A) when birth rates and death rates become stable (B) when there is not enough food (C) as the population grows (D) all of the above,A,"A population cant keep growing bigger and bigger forever. Sooner or later, it will run out of things it needs. For a given species, there is a maximum population that can be supported by the environment. This maximum is called the carrying capacity. When a population gets close to the carrying capacity, it usually grows more slowly. You can see this in Figure 18.16. When the population reaches the carrying capacity, it stops growing. "
the epididymis is over 20 feet long in adult males.,(A) true (B) false,A,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
the testes store sperm until they leave the body.,(A) true (B) false,B,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
what is the organ where sperm cells mature?,(A) testes (B) epididymis (C) vas deferens (D) penis,B,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
what organ allows sperm cells to travel to the urethra?,(A) testes (B) epididymis (C) vas deferens (D) penis,C,"The male reproductive organs include the penis, testes, and epididymis ( Figure 1.1). The figure also shows other parts of the male reproductive system. The penis is a cylinder-shaped organ. It contains the urethra. The urethra is a tube that carries urine out of the body. The urethra also carries sperm out of the body. This drawing shows the organs of the male reproductive system. It shows the organs from the side. Find each organ in the drawing as you read about it in the text. The two testes (singular, testis) are egg-shaped organs. They produce sperm and secrete testosterone. The testes are found inside of the scrotum. The scrotum is a sac that hangs down outside the body. The scrotum also contains the epididymis. The testes, being in the scrotum outside the body, allow the temperature of the sperm to be maintained at a few degrees lower than body temperature. This is necessary for the stability of these reproductive cells. The epididymis is a tube that is about six meters (20 feet) long in adults. It is tightly coiled, so it fits inside the scrotum. It rests on top of the testes. The epididymis is where sperm grow larger and mature. The epididymis also stores sperm until they leave the body. Other parts of the male reproductive system include the vas deferens and the prostate gland. Both of these structures are pictured below ( Figure 1.1). The vas deferens is a tube that carries sperm from the epididymis to the urethra. The prostate gland secretes a fluid that mixes with sperm to help form semen. The prostate gland is located beneath the bladder. Semen is a ""milky"" liquid that carries sperm through the urethra and out of the body. In addition to sperm cells, semen contains sugars (fructose) which provide energy to the sperm cells, and enzymes and other substances which help the sperm survive. "
semen is formed with a fluid secreted by the,(A) testes (B) epididymis (C) vas deferens (D) prostate gland,D,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
what organ or gland surrounds the urethra just below the bladder?,(A) the testes (B) the vas deferens (C) the Cowper’s gland (D) the prostate gland,D,"1. As you can see above ( Figure 1.1), the kidneys are two bean-shaped organs. Kidneys filter and clean the blood and form urine. They are about the size of your fists and are found near the middle of the back, just below your ribcage. 2. Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder. 3. The urinary bladder is a hollow and muscular organ. It is shaped a little like a balloon. It is the organ that collects urine. 4. Urine leaves the body through the urethra. The kidneys filter the blood that passes through them, and the urinary bladder stores the urine until it is released from the body. "
what organ or gland sits on top of the testes?,(A) the prostate gland (B) the vas deferens (C) the epididymis (D) the scrotum,C,"The male reproductive organs include the penis, testes, epididymis, vas deferens, and prostate gland. These organs are shown in Figure 22.1. The figure also shows some other parts of the male reproductive system. Find each organ in the drawing as you read about it below. For a cartoon about the male reproductive system, watch this video: http MEDIA Click image to the left or use the URL below. URL:  The penis is an external, cylinder-shaped organ that contains the urethra. The urethra is the tube that carries urine out of the body. It also carries sperm out of the body. The two testes (testis, singular) are oval organs that produce sperm and secrete testosterone. They are located inside a sac called the scrotum that hangs down outside the body. The scrotum also contains the epididymis. "
"of all the organ systems, the reproductive system is the only one with significant differences between males and females.",(A) true (B) false,A,Other reproductive system disorders include injuries and noninfectious diseases. These are different in males and females. 
males make some of the female sex hormone estrogen.,(A) true (B) false,A,"Two functions of the female reproductive system are similar to the functions of the male reproductive system: producing gametes and secreting a major sex hormone. In the case of females, however, the gametes are eggs, and they are produced by the ovaries. The hormone is estrogen, which is the main sex hormone in females. Estrogen has two major roles: During adolescence, estrogen causes the changes of puberty. It causes the reproductive organs to mature. It also causes other female traits to develop. For example, it causes the breasts to grow and the hips to widen. During adulthood, estrogen is needed for a woman to release eggs from the ovaries. The female reproductive system has another important function, which is not found in males. It supports a baby as it develops before birth. It also gives birth to the baby at the end of pregnancy. "
what is the role of testosterone during the teen years?,(A) causes male traits to develop (B) causes the reproductive organs to mature (C) allows for muscle growth (D) all of the above,D,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
what is the role of testosterone during adulthood?,(A) helps in sperm production (B) causes male traits to develop (C) causes the reproductive organs to mature (D) all of the above,A,"The male reproductive system has two main functions: producing sperm and releasing testosterone. Sperm are male gametes, or reproductive cells. Sperm form when certain cells in the male reproductive system divide by meiosis to form haploid cells. Being haploid means they have half the number of chromosomes of other cells in the body. An adult male may produce millions of sperm each day! Testosterone is the major sex hormone in males. Testosterone has two primary roles: 1. During adolescence, testosterone causes most of the changes associated with puberty. It causes the reproduc- tive organs to mature. It also causes other adult male traits to develop. For example, it causes the voice to deepen and facial hair to start growing. 2. During adulthood, testosterone is needed for the production of sperm. "
what process forms sperm cells?,(A) mitosis (B) meiosis (C) the cell cycle (D) fertilization,B,"It takes up to two months for mature sperm to form. The process occurs in several steps: 1. Special cells in the testes go through mitosis to make identical copies of themselves. 2. The copies of the original cells divide by meiosis. This results in haploid cells called spermatids. These cells lack tails and cannot yet swim. 3. Spermatids move from the testes to the epididymis, where they slowly mature. For example, they grow a tail and lose some of the cytoplasm from the head. 4. Once sperm are mature, they can swim. The mature sperm remain in the epididymis until it is time for them to leave the body. Sperm leave the epididymis through the vas deferens. As they travel through the vas deferens, they pass by the prostate and other glands. The sperm mix with secretions from these glands, forming semen. Semen travels through the urethra and leaves the body through the penis. A teaspoon of semen may contain as many as half a billion sperm! "
how many chromosomes are in a human sperm cell?,(A) 1 (B) 2 (C) 23 (D) 46,C,"In species with sexual reproduction, each cell of the body has two copies of each chromosome. For example, human beings have 23 different chromosomes. Each body cell contains two of each chromosome, for a total of 46 chromosomes. You can see the 23 pairs of human chromosomes in Figure 5.13. The number of different types of chromosomes is called the haploid number. In humans, the haploid number is 23. The number of chromosomes in normal body cells is called the diploid number. The diploid number is twice the haploid number. In humans, the diploid number is two times 23, or 46. "
what is a gamete?,(A) a haploid sex cell (B) a reproductive cell (C) a sperm or egg cell (D) all of the above,D,Sexual reproduction is more complicated. It involves two parents. Special cells called gametes are produced by the parents. A gamete produced by a female parent is generally called an egg. A gamete produced by a male parent is usually called a sperm. An offspring forms when two gametes unite. The union of the two gametes is called fertilization. You can see a human sperm and egg uniting in Figure 5.12. The initial cell that forms when two gametes unite is called a zygote. 
an egg can be fertilized any day of the monthly cycle.,(A) true (B) false,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
"during menstruation, bleeding occurs as tissue breaks away from the uterus.",(A) true (B) false,A,"The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. While the egg and follicle are developing in the ovary, tissues are building up inside the uterus, the reproductive organ where the baby would develop. The uterus develops a thick lining covered in tiny blood vessels. This prepares the uterus to receive an egg that could develop into a child (a fertilized egg). The occurs during the first part of the cycle. Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation. If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. If a sperm does not enter an egg, the lining of the uterus breaks down. Blood and other tissues from the lining break off from the uterus. They pass through the vagina and out of the body. This is called menstruation. Menstruation is also called a menstrual period. It lasts about 4 days, on average. When the menstrual period ends, the cycle repeats. Some women feel discomfort during this process. Some people think that the average length of a menstrual period is the same as the normal length. They assume that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in length. This is usually normal. The average length of the cycle (time between menstrual periods) is about 28 days, but there is no normal cycle length. Some women experience cramping and pain before and during menstruation. "
the uterus thickens each month,(A) to allow the unfertilized egg to easily flow through (B) so it can accept a fertilized egg (C) to lessen menstruation (D) to allow ovulation to occur,B,"Egg production in the ovary is part of the menstrual cycle. The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month on average. These changes include the development of an egg and follicle in the ovary. While the egg is developing, other changes are taking place in the uterus. It develops a thick lining that is full of tiny blood vessels. The lining prepares the uterus to receive a fertilized egg if fertilization actually takes place. If fertilization doesnt occur, the egg passes through the uterus and vagina and out of the body. The lining of the uterus also breaks down. Blood and other tissues from the lining pass through the vagina and leave the body. This is called menstruation. Menstruation is also called a menstrual period. It typically lasts about 4 days. When the menstrual period ends, the cycle begins repeats. "
"if an egg is not fertilized,",(A) the uterus lining breaks down (B) the uterus lining thickens (C) ovulation occurs (D) menstruation stops,A,"Egg production takes place in the ovaries. It occurs in several steps: 1. Before birth, special cells in the ovaries go through mitosis to make identical daughter cells. 2. The daughter cells then start to divide by meiosis. However, they go though only the first of the two cell divisions of meiosis at this time. They remain in that stage until the girl goes through puberty. 3. After puberty, an egg develops in an ovary about once a month. As you can see in Figure 22.4, the egg rests in a nest of cells called a follicle. The follicle and egg grow larger and go through other changes. 4. After a couple of weeks, the egg bursts out of the follicle and through the wall of the ovary. This is called ovulation. After ovulation occurs, the moving fingers of the nearby fallopian tube sweep the egg into the tube. Fertilization may occur if sperm reach the egg while it is passing through the fallopian tube. If this happens, the egg finally completes meiosis. This results in two daughter cells that differ in size. The smaller cell is called a polar body. It soon breaks down and disappears. The larger cell is the fertilized egg, which will develop into a new human being. "
the monthly cycle stops,(A) never (B) while the egg is flowing through the uterus (C) during ovulation (D) during pregnancy,D,"The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. While the egg and follicle are developing in the ovary, tissues are building up inside the uterus, the reproductive organ where the baby would develop. The uterus develops a thick lining covered in tiny blood vessels. This prepares the uterus to receive an egg that could develop into a child (a fertilized egg). The occurs during the first part of the cycle. Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation. If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. If a sperm does not enter an egg, the lining of the uterus breaks down. Blood and other tissues from the lining break off from the uterus. They pass through the vagina and out of the body. This is called menstruation. Menstruation is also called a menstrual period. It lasts about 4 days, on average. When the menstrual period ends, the cycle repeats. Some women feel discomfort during this process. Some people think that the average length of a menstrual period is the same as the normal length. They assume that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in length. This is usually normal. The average length of the cycle (time between menstrual periods) is about 28 days, but there is no normal cycle length. Some women experience cramping and pain before and during menstruation. "
menstruation usually lasts about,(A) 1 day (B) 4 days (C) 14 days (D) 28 days,B,"The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. While the egg and follicle are developing in the ovary, tissues are building up inside the uterus, the reproductive organ where the baby would develop. The uterus develops a thick lining covered in tiny blood vessels. This prepares the uterus to receive an egg that could develop into a child (a fertilized egg). The occurs during the first part of the cycle. Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation. If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. If a sperm does not enter an egg, the lining of the uterus breaks down. Blood and other tissues from the lining break off from the uterus. They pass through the vagina and out of the body. This is called menstruation. Menstruation is also called a menstrual period. It lasts about 4 days, on average. When the menstrual period ends, the cycle repeats. Some women feel discomfort during this process. Some people think that the average length of a menstrual period is the same as the normal length. They assume that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in length. This is usually normal. The average length of the cycle (time between menstrual periods) is about 28 days, but there is no normal cycle length. Some women experience cramping and pain before and during menstruation. "
how long is the normal monthly cycle?,(A) 14 days (B) 28 days (C) 30 days (D) There is no normal cycle length,D,"The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. While the egg and follicle are developing in the ovary, tissues are building up inside the uterus, the reproductive organ where the baby would develop. The uterus develops a thick lining covered in tiny blood vessels. This prepares the uterus to receive an egg that could develop into a child (a fertilized egg). The occurs during the first part of the cycle. Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation. If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. If a sperm does not enter an egg, the lining of the uterus breaks down. Blood and other tissues from the lining break off from the uterus. They pass through the vagina and out of the body. This is called menstruation. Menstruation is also called a menstrual period. It lasts about 4 days, on average. When the menstrual period ends, the cycle repeats. Some women feel discomfort during this process. Some people think that the average length of a menstrual period is the same as the normal length. They assume that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in length. This is usually normal. The average length of the cycle (time between menstrual periods) is about 28 days, but there is no normal cycle length. Some women experience cramping and pain before and during menstruation. "
microscopes have been around for over 400 years.,(A) true (B) false,A,"The microscope was invented more than four centuries ago. In the late 1500s, two Dutch eyeglass makers, Zacharias Jansen and his father Hans, built the first microscope. They put several magnifying lenses in a tube. They discovered that using more than one lens magnified objects more than a single lens. Their simple microscope could make small objects appear nine times bigger than they really were. "
antoine van leeuwenhoek discovered the cell by looking at cork through a microscope.,(A) true (B) false,B,"British scientist Robert Hooke first discovered cells in 1665. He was one of the earliest scientists to study living things under a microscope. He saw that cork was divided into many tiny compartments, like little rooms. (Do the cells in Figure 3.1 look like little rooms to you too?) Hooke called these little rooms cells. Cork comes from trees, so what Hooke observed was dead plant cells. In the late 1600s, Dutch scientist Anton van Leeuwenhoek made more powerful microscopes. He used them to observe cells of other organisms. For example, he saw human blood cells and bacterial cells. Over the next century, microscopes were improved and more cells were observed. "
who is known as the father of microscopy?,(A) Zaccharias Janssen (B) Robert Hooke (C) Antoine van Leeuwenhoek (D) Antoine Hooke,C,"Over four hundred years ago, two Dutch spectacle makers, Zaccharias Janssen and his son Hans, were experimenting with several lenses in a tube. They discovered that nearby objects appeared greatly enlarged, or magnified. This was the forerunner of the compound microscope and of the telescope. In 1665, Robert Hooke, an English natural scientist, used a microscope to zoom in on a piece of cork - the stuff that makes up the stoppers in wine bottles, which is made from tree bark. Inside of cork, he discovered tiny structures, which he called cells. It turns out that cells are the smallest structural unit of living organisms. This finding eventually led to the development of the theory that all living things are made of cells. Without microscopes, this discovery would not have been possible, and the cell theory would not have been developed. Hookes discovery of the cell set the stage for other scientists to discover other types of organisms. After Hooke, the ""father of microscopy,"" Dutch scientist Antoine van Leeuwenhoek ( Figure 1.2) taught himself to make one of the first microscopes. In one of his early experiments, van Leeuwenhoek took a sample of scum from his own teeth and used his microscope to discover bacteria, the smallest living organism on the planet. Using microscopes, van Leeuwenhoek also discovered one-celled protists and sperm cells. Today, microscopes are used by all types of scientists, including cell biologists, microbiologists, virologists, forensic scientists, entomologists, taxonomists, and many other types. Antoine van Leeuwenhoek, a Dutch cloth merchant with a passion for microscopy. "
who discovered single-celled protists?,(A) Zaccharias Janssen (B) Robert Hooke (C) Antoine van Leeuwenhoek (D) Antoine Hooke,C,"Most protists are so small that they can be seen only with a microscope. Protists are mostly unicellular (one-celled) eukaryotes. A few protists are multicellular (many-celled) and surprisingly large. For example, kelp is a multicellular protist that can grow to be over 100-meters long ( Figure 1.1). Multicellular protists, however, do not show cellular specialization or differentiation into tissues. That means their cells all look the same and, for the most part, function the same. On the other hand, your cells often are much different from each other and have special jobs. Kelp is an example of a muticellular pro- tist. "
what type of microscope would allow scientists to find the shape and surface texture of small objects?,(A) light microscope (B) transmission electron microscope (C) scanning electron microscope (D) scanning acoustic microscope,C,"Some modern microscopes use light, as Hookes and van Leeuwenhoeks did. Others may use electron beams or sound waves. Researchers now use these four types of microscopes: 1. Light microscopes allow biologists to see small details of a specimen. Most of the microscopes used in schools and laboratories are light microscopes. Light microscopes use lenses, typically made of glass or plastic, to focus light either into the eye, a camera, or some other light detector. The most powerful light microscopes can make images up to 2,000 times larger. 2. Transmission electron microscopes (TEM) focus a beam of electrons through an object and can make an image up to two million times bigger, with a very clear image. 3. Scanning electron microscopes (SEM) allow scientists to find the shape and surface texture of extremely small objects, including a paperclip, a bedbug, or even an atom. These microscopes slide a beam of electrons across the surface of a specimen, producing detailed maps of the surface of objects. Magnification in a SEM can be controlled over a range from about 10 to 500,000 times. 4. Scanning acoustic microscopes use sound waves to scan a specimen. These microscopes are useful in biology and medical research. "
which of the following is a protist?,(A) a palm tree (B) a ladybug (C) a mushroom (D) None of the above are protists,D,"Animal-like protists are called protozoa. Protozoa are single-celled eukaryotes that share some traits with animals. Like animals, they can move, and they are heterotrophs. That means they eat things outside of themselves instead of producing their own food. Animal-like protists are very small, measuring only about 0.010.5mm. Animal-like protists include the flagellates, ciliates, and the sporozoans. "
the most powerful light microscopes can make images up to __________ times larger.,(A) 20 (B) 200 (C) 2 (D) 000 (E) d 20 (F) 000,C,"These early microscopes used lenses to refract light and create magnified images. This type of microscope is called a light microscope. Light microscopes continued to improve and are still used today. The microscope you might use in science class is a light microscope. The most powerful light microscopes now available can make objects look up to 2000 times their actual size. You can learn how to use a light microscope by watching this short video: http MEDIA Click image to the left or use the URL below. URL:  To see what you might observe with a light microscope, watch the following video. It shows some amazing creatures in a drop of stagnant water from an old boat. What do you think the creatures might be? Do they look like any of van Leeuwenhoeks animalcules in Figure 1.12? MEDIA Click image to the left or use the URL below. URL:  For an object to be visible with a light microscope, it cant be smaller than the wavelength of visible light (about 550 nanometers). To view smaller objects, a different type of microscope, such as an electron microscope, must be used. Electron microscopes pass beams of electrons through or across an object. They can make a very clear image that is up to 2 million times bigger than the actual object. An electron microscope was used to make the image of the ant head in Figure 1.10. "
pearls are produced by mollusks.,(A) true (B) false,A,"Two natural products of mollusks used for decorations and jewelry are pearls and nacre. A pearl is the hard, round object produced within the mantle of a living shelled mollusk. Pearls are produced by many bivalves when a tiny particle of sand or grit is trapped between the mantle and the shell. Its as if the mollusk has a splinter. The mollusk forms a protective covering around the irritant. Most pearls used as jewelry are made by pearl oysters and freshwater mussels; most of the ones sold are cultured and not wild. Natural pearls have been highly valued as gemstones and objects of beauty for many centuries. The most desirable pearls are produced by oysters and river mussels. The substance used to form the pearl covering is made from the mother of pearl material that lines the interior of the shell. Mother of pearl is also known as nacre. Nacre is the iridescent inner shell layer. It can be found in buttons, watch faces, knives, guns, and jewelry. It is also used to decorate various musical instruments. "
mollusks are the only organisms to have a radula.,(A) true (B) false,A,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
the mollusk shell is formed by the,(A) radula (B) mantle (C) chitin (D) gills,B,"The Mollusks body is often divided into different parts ( Figure 1.2): On the beach, you can find a wide variety of mollusk shells. 1. A head with eyes or tentacles. 2. In most species, a muscular foot, which helps the mollusk move. Some mollusks use the foot for burrowing into the sand, and others use it for jet-propulsion. 3. A mantle, or fold of the outer skin lining the shell. The mantle often releases calcium carbonate, which creates an external shell, just like the ones you find on the beach. The shell is made of chitin, a tough, semitransparent substance. 4. A mass housing the organs. 5. A complete digestive tract that begins at the mouth and runs to the anus. 6. Most ocean mollusks have a gill or gills to absorb oxygen from the water. 7. Many species have a feeding structure, the radula, found only in mollusks. The radula can be thought of as a ""tongue-like"" structure. The radula is made mostly of chitin. Types of radulae range from structures used to scrape algae off of rocks to the beaks of squid and octopuses. This is the basic body plan of a mollusk. Note the mantle, gills, and radula. Keep in mind the basic body plan can differ slightly among the mollusks. "
the foot of a squid is probably used for,(A) movement along a surface (B) burrowing into the sand (C) jet-propulsion (D) all of the above,C,"Cephalopods include the octopus and squid. They have a prominent head and a well-developed brain. Typically the foot has been modified into a set of arms or tentacles. Members of this class can change color. They can also change texture and body shape, and, and if those camouflage techniques dont work, they can still ""disappear"" in a cloud of ink. Cephalopods have three hearts that pump blue blood, theyre jet powered by their muscular foot, and theyre found in all oceans of the world. Cephalopods are thought to be the most intelligent of invertebrates. They have eyes and other senses that rival those of humans. Many cephalopods are active and efficient predators. What features do you think allows for this? (left) An example of a gastropod species, the ostrich foot. (right) A Caribbean reef squid, an example of a cephalopod. "
what parts of the mollusk contain chitin?,(A) the shell and mantle (B) the shell and the radula (C) the radula and the mantle (D) the gills and the mantle cavity,B,"The Mollusks body is often divided into different parts ( Figure 1.2): On the beach, you can find a wide variety of mollusk shells. 1. A head with eyes or tentacles. 2. In most species, a muscular foot, which helps the mollusk move. Some mollusks use the foot for burrowing into the sand, and others use it for jet-propulsion. 3. A mantle, or fold of the outer skin lining the shell. The mantle often releases calcium carbonate, which creates an external shell, just like the ones you find on the beach. The shell is made of chitin, a tough, semitransparent substance. 4. A mass housing the organs. 5. A complete digestive tract that begins at the mouth and runs to the anus. 6. Most ocean mollusks have a gill or gills to absorb oxygen from the water. 7. Many species have a feeding structure, the radula, found only in mollusks. The radula can be thought of as a ""tongue-like"" structure. The radula is made mostly of chitin. Types of radulae range from structures used to scrape algae off of rocks to the beaks of squid and octopuses. This is the basic body plan of a mollusk. Note the mantle, gills, and radula. Keep in mind the basic body plan can differ slightly among the mollusks. "
the head region of a mollusk contains the,(A) gills and mantle cavity (B) the foot and tentacles (C) the tentacles and radula (D) the stomach and the radula,C,"Mollusks have a true coelom and complete digestive system. They also have circulatory and excretory systems. They have a heart that pumps blood, and organs that filter out wastes from the blood. You can see some other traits of mollusks in the garden snail in Figure 12.16. Like the snail, many other mollusks have a hard outer shell. It is secreted by special tissue called mantle on the outer surface of the body. The shell covers the top of the body and encloses the internal organs. Most mollusks have a distinct head region. The head may have tentacles for sensing the environment and grasping food. Mollusks generally have a muscular foot, which may be used for walking or other purposes. A unique feature of mollusks is the radula. This is a feeding organ with teeth made of chitin. It is located in front of the mouth in the head region. It can be used to scrape algae off rocks or drill holes in the shells of prey. You can see the radula of the sea slug in Figure 12.17. "
what type of worms are most closely related to mollusks?,(A) flatworms (B) roundworms (C) segmented worms (D) shelled worms,C,"Mollusks are probably most closely related to organisms in the phylum Annelida, also known as segmented worms. This phylum includes the earthworm and leech. Scientists believe these two groups are related because, when they are in the early stage of development, they look very similar. Mollusks also share features of their organ systems with segmented worms. Unlike segmented worms, however, mollusks do not have body segmentation. The basic mollusk body shape is usually quite different as well. "
"anaerobic exercises such as running, increase muscle strength.",(A) true (B) false,B,"Anaerobic exercises comprise brief periods of physical exertion and high-intensity, strength-training activities. Anaerobic exercises cause muscles to get bigger and stronger. Anaerobic exercises use a resistance against which the muscle has to work to lift or push away. The resistance can be a weight or a persons own body weight (Figure "
regular physical exercise can prevent lifestyle diseases.,(A) true (B) false,A,"Regular physical exercise is important in preventing lifestyle diseases such as cardiovascular disease, some types of cancer, type 2 diabetes, and obesity. Regular exercise also improves the health of the muscular system. Muscles that are exercised are bigger and stronger than muscles that are not exercised. Exercise improves both muscular strength and muscular endurance. Muscular strength is the ability of a muscle to use force during a contraction. Muscular endurance is the ability of a muscle to continue to contract over a long time without getting tired. Exercises are grouped into three types depending on the effect they have on the body: Aerobic exercises, such as cycling, walking, and running, increase muscular endurance and cardiovascular health. Anaerobic exercises, such as weight training or sprinting, increase muscle strength. Flexibility exercises, such as stretching, improve the range of motion of muscles and joints. Regular stretching helps people avoid activity-related injuries. "
what is the goal of flexibility exercises?,(A) to increase cardiovascular health (B) to increase muscle strength (C) to improve the range of motion of muscles and joints (D) to increase the efficient use of oxygen,C,You are less likely to have a muscle injury if you exercise regularly and have strong muscles. Stretching also helps prevent muscle injuries. Stretching improves the range of motion of muscles and tendons at joints. You should always warm up before stretching or doing any type of exercise. Warmed-up muscles and tendons are less likely to be injured. One way to warm up is to jog slowly for a few minutes. 
how to anaerobic exercises work on muscles?,(A) Anaerobic exercises allow the muscle to use oxygen more efficiently (B) Anaerobic exercises use a resistance against which the muscle has to work (C) Anaerobic exercises train the heart to pump blood more efficiently (D) all of the above,B,"Anaerobic exercises comprise brief periods of physical exertion and high-intensity, strength-training activities. Anaerobic exercises cause muscles to get bigger and stronger. Anaerobic exercises use a resistance against which the muscle has to work to lift or push away. The resistance can be a weight or a persons own body weight (Figure "
which of the following are aerobic activities?,(A) basketball and tennis (B) weight training and sprinting (C) downhill skiing (D) mowing lawn and shoveling snow,D,"Aerobic exercises are exercises in which a low to moderate level of exertion can be sustained over long periods. These are exercises that cause your heart to beat faster and allow your muscles to use oxygen to contract. If you exercise aerobically, overtime, your muscles will not get easily tired, and you will use oxygen more efficiently. Aerobic exercise (Figure 1.2) also helps improve cardiac muscle. "
what diseases can be reduced or prevented with regular exercise?,(A) heart disease (B) type II diabetes (C) some types of cancer (D) all of the above,D,"Regular physical exercise is important in preventing lifestyle diseases such as cardiovascular disease, some types of cancer, type 2 diabetes, and obesity. Regular exercise also improves the health of the muscular system. Muscles that are exercised are bigger and stronger than muscles that are not exercised. Exercise improves both muscular strength and muscular endurance. Muscular strength is the ability of a muscle to use force during a contraction. Muscular endurance is the ability of a muscle to continue to contract over a long time without getting tired. Exercises are grouped into three types depending on the effect they have on the body: Aerobic exercises, such as cycling, walking, and running, increase muscular endurance and cardiovascular health. Anaerobic exercises, such as weight training or sprinting, increase muscle strength. Flexibility exercises, such as stretching, improve the range of motion of muscles and joints. Regular stretching helps people avoid activity-related injuries. "
why is it important to warm-up before any intense physical activity?,(A) to prevent muscle strains and tendinitis (B) to increase the heart rate (C) to increase blood flow to the muscles (D) all of the above,D,You are less likely to have a muscle injury if you exercise regularly and have strong muscles. Stretching also helps prevent muscle injuries. Stretching improves the range of motion of muscles and tendons at joints. You should always warm up before stretching or doing any type of exercise. Warmed-up muscles and tendons are less likely to be injured. One way to warm up is to jog slowly for a few minutes. 
"when smooth muscles contract, bones move.",(A) true (B) false,B,"When skeletal muscles contract, bones move. But how do muscles make your bones move? A voluntary muscles usually works across a joint. It is attached to both the bones on either side of the joint by strong cords called tendons. A tendon is a tough band of connective tissue that connects a muscle to a bone. Tendons are similar to ligaments, except that ligaments join bones to each other. Muscles move the body by contracting against the skeleton. When muscles contract, they get shorter. By contracting, muscles pull on bones and allow the body to move. Muscles can only contract. They cannot actively extend, though they can move or relax back into the non-contracted neutral position. Therefore, to move bones in opposite directions, pairs of muscles must work in opposition. Each muscle in the pair works against the other to move bones at the joints of the body. The muscle that contracts to cause a joint to bend is called the flexor. The muscle that contracts to cause the joint to straighten is called the extensor. When one muscle is contracted, the other muscle from the pair is always elongated. For example, the biceps and triceps muscles work together to allow you to bend and straighten your elbow. When you want to bend your elbow, your biceps muscle contracts (Figure 1.1), and, at the same time, the triceps muscle relaxes. The biceps is the flexor, and the triceps is the extensor of your elbow joint. Other muscles that work together are the quadriceps and hamstrings used to bend and straighten the knee, and the pectorals and trapezius used to move the arms and shoulders forward and backward. During daily routines we do not use muscles equally. For example, we use our biceps more than our triceps due to lifting against gravity. "
tendons join two bones to each other.,(A) true (B) false,B,"You can see the bundles of muscle fibers that make up a skeletal muscle in Figure 16.19. You can also see in the figure how the muscle is attached to a bone by a tendon. Tendons are tough connective tissues that anchor skeletal muscles to bones throughout the body. Many skeletal muscles are attached to the ends of bones where they meet at a joint. The muscles span the joint and connect the bones. When the muscles contract, they pull on the bones, causing them to move. "
the biceps work together with the,(A) pectorals (B) triceps (C) quadriceps (D) muscles,B,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
which muscles are used to move the arms forward and backward?,(A) quadriceps and pectorals (B) biceps and triceps (C) pectorals and trapezius (D) biceps and pectorals,C,"Muscles can only contract. They cant actively lengthen. Therefore, to move bones back and forth at a joint, skeletal muscles must work in pairs. For example, the bicep and triceps muscles of the upper arm work as a pair. You can see how this pair of muscles works in Figure 16.20. When the bicep muscle contracts, it bends the arm at the elbow. When the triceps muscle contracts, it straightens the arm. "
which muscles are used to bend the knee?,(A) quadriceps and hamstrings (B) pectorals and trapezius (C) hamstrings and trapezius (D) quadriceps and pectorals,A,"When skeletal muscles contract, bones move. But how do muscles make your bones move? A voluntary muscles usually works across a joint. It is attached to both the bones on either side of the joint by strong cords called tendons. A tendon is a tough band of connective tissue that connects a muscle to a bone. Tendons are similar to ligaments, except that ligaments join bones to each other. Muscles move the body by contracting against the skeleton. When muscles contract, they get shorter. By contracting, muscles pull on bones and allow the body to move. Muscles can only contract. They cannot actively extend, though they can move or relax back into the non-contracted neutral position. Therefore, to move bones in opposite directions, pairs of muscles must work in opposition. Each muscle in the pair works against the other to move bones at the joints of the body. The muscle that contracts to cause a joint to bend is called the flexor. The muscle that contracts to cause the joint to straighten is called the extensor. When one muscle is contracted, the other muscle from the pair is always elongated. For example, the biceps and triceps muscles work together to allow you to bend and straighten your elbow. When you want to bend your elbow, your biceps muscle contracts (Figure 1.1), and, at the same time, the triceps muscle relaxes. The biceps is the flexor, and the triceps is the extensor of your elbow joint. Other muscles that work together are the quadriceps and hamstrings used to bend and straighten the knee, and the pectorals and trapezius used to move the arms and shoulders forward and backward. During daily routines we do not use muscles equally. For example, we use our biceps more than our triceps due to lifting against gravity. "
"if your heart contracts 75 times a minute, how many times does it contract each day?",(A) about 2 (B) 000 (C) b about 10 (D) 000 (E) c slightly over 100 (F) 000 (G) d about 1 (H) 000 (I) 000,C,"To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract, followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through the heart. Contractions of cardiac muscles arent under voluntary control. They are controlled by a cluster of special cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they contract in the correct sequence and with just the right timing. "
which of the following are functions of smooth muscle?,(A) helps a woman to push out her baby (B) regulates air flow in lungs (C) move food through the digestive tract (D) all of the above,D,"Smooth muscles and cardiac muscles are not attached to bone. Recall that these types of muscles are under involuntary control. Smooth muscle is responsible for the contractility of hollow organs, such as blood vessels, the gastrointestinal tract, the bladder, or the uterus. Like skeletal muscles, smooth muscle fibers do contract together, causing the muscle to shorten. Smooth muscles have numerous functions, including the following. The smooth muscle in the uterus helps a woman to push out her baby. In the bladder, smooth muscle helps to push out urine. Smooth muscles move food through the digestive tract. In arteries, smooth muscle movements maintain the arteries diameter. Smooth muscle regulates air flow in lungs. Smooth muscle in the lungs helps the airways to expand and contract as necessary. Smooth muscles in arteries and veins are largely responsible for regulation of blood pressure. Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. If your heart beats 75 times a minute, how many times does it beat in an hour? A day? A year? 85 years? "
a mutation is a change in the dna sequence. the change is always harmful.,(A) true (B) false,B,"The process of DNA replication is not always 100% accurate. Sometimes the wrong base is inserted in the new strand of DNA. This wrong base could become permanent. A permanent change in the sequence of DNA is known as a mutation. Small changes in the DNA sequence are usually point mutations, which is a change in a single nucleotide. Once DNA has a mutation, that mutation will be copied each time the DNA replicates. After cell division, each resulting cell will carry the mutation. A mutation may have no effect. However, sometimes a mutation can cause a protein to be made incorrectly. A defect in the protein can affect how well the protein works, or whether it works at all. Usually the loss of a protein function is detrimental to the organism. In rare circumstances, though, the mutation can be beneficial. Mutations are a mechanism for how species evolve. For example, suppose a mutation in an animals DNA causes the loss of an enzyme that makes a dark pigment in the animals skin. If the population of animals has moved to a light colored environment, the animals with the mutant gene would have a lighter skin color and be better camouflaged. So in this case, the mutation is beneficial. "
deletions occur when a segment of dna is repeated.,(A) true (B) false,B,"Mutations may also occur in chromosomes ( Figure 1.1). These mutations are going to be fairly large mutations, possible affecting many genes. Possible types of mutations in chromosomes include: 1. Deletion: When a segment of DNA is lost, so there is a missing segment in the chromosome. These usually result in many genes missing from the chromosome. 2. Duplication: When a segment of DNA is repeated, creating a longer chromosome. These usually result in multiple copies of genes in the chromosome. 3. Inversion: When a segment of DNA is flipped and then reattached to the same chromosome. 4. Insertion: When a segment of DNA from one chromosome is added to another, unrelated chromosome. 5. Translocation: When two segments from different chromosomes change positions. "
what type of mutation occurs when a segment of dna is flipped and then reattached to the same chromosome?,(A) deletion (B) inversion (C) insertion (D) translocation,B,"Mutations may also occur in chromosomes ( Figure 1.1). These mutations are going to be fairly large mutations, possible affecting many genes. Possible types of mutations in chromosomes include: 1. Deletion: When a segment of DNA is lost, so there is a missing segment in the chromosome. These usually result in many genes missing from the chromosome. 2. Duplication: When a segment of DNA is repeated, creating a longer chromosome. These usually result in multiple copies of genes in the chromosome. 3. Inversion: When a segment of DNA is flipped and then reattached to the same chromosome. 4. Insertion: When a segment of DNA from one chromosome is added to another, unrelated chromosome. 5. Translocation: When two segments from different chromosomes change positions. "
what type of mutation is the following: caggttgcaag to cagttgcaag,(A) deletion (B) frameshift mutation (C) point mutation (D) all of the above,D,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
which best describes a translocation?,(A) A segment of DNA moves from chromosome 8 to chromosome 2 (B) A segment of DNA from chromosome 8 is lost (C) A segment of DNA from chromosome 2 is repeated (D) A segment of DNA from chromosome 8 is swapped with a segment from,D,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
what type of mutation is the following: agttaccaggc to agtttaccaggc,(A) deletion (B) inversion (C) insertion (D) translocation,C,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
why are chromosomal mutations dangerous?,(A) Chromosomal mutations are going to be fairly large (B) possible affecting many (C) b Chromosomal mutations always result in deletions (D) c Chromosomal mutations are always frameshift mutations (E) d all of the above,A,"The effect of a mutation is likely to depend as well on the type of mutation that occurs. A mutation that changes all or a large part of a chromosome is called a chromosomal mutation. This type of mutation tends to be very serious. Sometimes chromosomes are missing or extra copies are present. An example is the mutation that causes Down syndrome. In this case, there is an extra copy of one of the chromosomes. Deleting or inserting a nitrogen base causes a frameshift mutation. All of the codons following the mutation are misread. This may be disastrous. To see why, consider this English-language analogy. Take the sentence The big dog ate the red cat. If the second letter of big is deleted, then the sentence becomes: The bgd oga tet her edc at. Deleting a single letter makes the rest of the sentence impossible to read. Some mutations change just one or a few bases in DNA. A change in just one base is called a point mutation. Table 5.1 compares different types of point mutations and their effects. Type Silent Missense Nonsense Description mutated codon codes for the same amino acid mutated codon codes for a different amino acid mutated codon is a prema- ture stop codon Example CAA (glutamine) ! CAG (glutamine) CAA (glutamine) ! CCA (proline) CAA (glutamine) ! UAA (stop) Effect none variable serious "
hair and nails are the two main components of the integumentary system.,(A) true (B) false,B,"Along with the skin, the integumentary system includes the nails and hair. Both the nails and hair contain the tough protein, keratin. The keratin forms fibers, which makes your nails and hair tough and strong. Keratin is similar in toughness to chitin, the carbohydrate found in the exoskeleton of arthropods. "
nails are like the claws of animals.,(A) true (B) false,A,"Nails are similar to claws in other animals. They cover the tips of fingers and toes. Fingernails and toenails both grow from nail beds. As the nail grows, more cells are added at the nail bed. Older cells get pushed away from the nail bed and the nail grows longer. There are no nerve endings in the nail. Otherwise cutting your nails would hurt a lot! Nails act as protective plates over the fingertips and toes. Fingernails also help in sensing the environment. The area under your nail has many nerve endings. These nerve endings allow you to receive more information about objects you touch. The Guinness Book of World Records began tracking record fingernail lengths in 1955. At that time the record was 1 foot 10.75 inches long. The current record-holder for men is from India, with a record of 20 feet 2.25 inches for all nails on his left hand, the longest being his thumbnail at 4 feet 9.6 inches. The record for women is held by an American woman. The record is 28 feet (850 cm) for all nails of both hands, with the longest nail on her right thumb at 2 feet 11 inches. Since adult nails grow at about 3 mm a month (1/10 of an inch), how long would it take to grow such long nails? "
"what animals, other than mammals, have hair?",(A) amphibians (B) reptiles (C) birds (D) None (E) mammals are the only animals to have hair,D,"Only mammals have hair. Hair is a fiber made mainly of the tough protein keratin. The cells of each hair are filled with keratin and no longer alive. The dead cells overlap each other, almost like shingles on a roof. They work like shingles as well, by helping shed water from hair. Head hair helps protect the scalp from sun exposure. It also helps insulate the body. It traps air so heat cant escape from the head. Hair in eyelashes and eyebrows helps keep water and dust out of the eyes. Hairs inside the nostrils of the nose trap dust and germs in the air so they cant reach the lungs. "
about how fast does hair grow?,(A) 6 feet a year (B) 1 inch a week (C) 6 inches a month (D) 6 inches a year,D,"Hair is one of the defining characteristics of mammals. In fact, mammals are the only animals to have hair. Hair sticks out from the epidermis, but it grows from the dermis ( Figure 1.1). Hair grows from inside the hair follicle. New cells grow in the bottom part of the hair, called the bulb. Older cells get pushed up, and the hair grows longer. The cells that make up the hair strand are dead and filled with the rope-like protein keratin. Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water loss from the skin. The sebaceous gland secretes sebum, which waterproofs the skin and hair. In humans, hair grows everywhere on the body except the soles of the feet and the palms of the hands, the lips, and the eyelids (except for eyelashes). Hair grows at a rate of about half an inch (1.25 cm) each month, or about 6 inches (15 cm) a year. Hair, especially on the head, helps to keep the body warm. The air traps a layer of warm air near the skin and acts like a warm blanket. Hair can also act as a filter. Nose hair helps to trap particles in the air that may otherwise travel to the lungs. Eyelashes shield eyes from dust and sunlight. Eyebrows stop salty sweat and rain from flowing into the eye. The worlds longest documented hair, according to Guinness World Records, belongs to Xie Qiuping of China at just under 18 feet 6 inches (5.627 m) when measured on May 8, 2004. She had been growing her hair since 1973 when she was 13 years old. "
what keeps hair and nails strong?,(A) the protein chitin (B) the protein keratin (C) the carbohydrate chitin (D) washing your hair daily and your hands often,B,"Along with the skin, the integumentary system includes the nails and hair. Both the nails and hair contain the tough protein, keratin. The keratin forms fibers, which makes your nails and hair tough and strong. Keratin is similar in toughness to chitin, the carbohydrate found in the exoskeleton of arthropods. "
"in humans, hair grows everywhere except",(A) the soles of the feet (B) the lips (C) the palms of the hands (D) All of the above are areas without hair,D,"Hair is one of the defining characteristics of mammals. In fact, mammals are the only animals to have hair. Hair sticks out from the epidermis, but it grows from the dermis ( Figure 1.1). Hair grows from inside the hair follicle. New cells grow in the bottom part of the hair, called the bulb. Older cells get pushed up, and the hair grows longer. The cells that make up the hair strand are dead and filled with the rope-like protein keratin. Hair, hair follicle, and oil glands. The oil, called sebum, helps to prevent water loss from the skin. The sebaceous gland secretes sebum, which waterproofs the skin and hair. In humans, hair grows everywhere on the body except the soles of the feet and the palms of the hands, the lips, and the eyelids (except for eyelashes). Hair grows at a rate of about half an inch (1.25 cm) each month, or about 6 inches (15 cm) a year. Hair, especially on the head, helps to keep the body warm. The air traps a layer of warm air near the skin and acts like a warm blanket. Hair can also act as a filter. Nose hair helps to trap particles in the air that may otherwise travel to the lungs. Eyelashes shield eyes from dust and sunlight. Eyebrows stop salty sweat and rain from flowing into the eye. The worlds longest documented hair, according to Guinness World Records, belongs to Xie Qiuping of China at just under 18 feet 6 inches (5.627 m) when measured on May 8, 2004. She had been growing her hair since 1973 when she was 13 years old. "
roles of nails include all of the following except,(A) the protection of the fingers and toes (B) maintaining warmth (C) sensing the environment (D) All of the above are roles of nails,B,"You may spend a lot of time and money on your hair and nails. You may think of them as accessories, like clothes or jewelry. However, like the skin, the hair and nails also play important roles in helping the body maintain homeostasis. "
the brain is part of the nervous system.,(A) true (B) false,A,"The central nervous system (CNS) ( Figure 1.1) is the largest part of the nervous system. It includes the brain and the spinal cord. The bony skull protects the brain. The spinal cord is protected within the bones of the spine, which are called vertebrae. "
hormones are made by the nervous system.,(A) true (B) false,B,"The endocrine system is a system of glands that release chemical messenger molecules into the blood stream. The messenger molecules are called hormones. Hormones act slowly compared with the rapid transmission of electrical impulses of the nervous system. Endocrine hormones must travel through the bloodstream to the cells they control, and this takes time. On the other hand, because endocrine hormones are released into the bloodstream, they travel to cells everywhere in the body. For a good visual introduction to the endocrine system, watch this short video: http MEDIA Click image to the left or use the URL below. URL: "
what two organ systems control all the other systems?,(A) the nervous and skeletal systems (B) the nervous and muscular systems (C) the nervous and endocrine systems (D) the muscular and endocrine systems,C,"Michelle was riding her scooter when she hit a hole in the street and started to lose control. She thought she would fall, but, in the blink of an eye, she shifted her weight and kept her balance. Her heart was pounding, but at least she didnt get hurt. How was she able to react so quickly? Michelle can thank her nervous system for that ( Figure 1.1). The nervous system, together with the endocrine system, controls all the other organ systems. The nervous system sends one type of signal around the body, and the endocrine system sends another type of signal around the body. The endocrine system makes and releases chemical messenger molecules, or hormones, which tell other body parts that a change or a reaction is necessary. So what type of signal does the nervous system send? Controlling muscles and maintaining balance are just two of the roles of the nervous system. The nervous system also lets you: Sense your surroundings with your eyes and other sense organs. Sense the environment inside of your body, including temperature. Control your internal body systems and keep them in balance. Staying balanced when riding a scooter requires control over the bodys muscles. The nervous system controls the muscles and maintains balance. Prepare your body to fight or flee in an emergency. Use language, think, learn, and remember. The nervous system works by sending and receiving electrical signals. The main organs of the nervous system are the brain and the spinal cord. The signals are carried by nerves in the body, similar to the wires that carry electricity all over a house. The signals travel from all over the body to the spinal cord and up to the brain, as well as moving in the other direction. For example, when Michelle started to fall off her scooter, her nervous system sensed that she was losing her balance. It responded by sending messages from her brain to muscles in her body. Some muscles tightened while others relaxed. Maybe these actions moved her hips or her arms. The nervous system, working together with the muscular and skeletal systems, allowed Michelle to react to the situation. As a result, Michelles body became balanced again. The messages released by the nervous system traveled through nerves. Just like the electricity that travels through wires, nerve quickly carry the electrical messages around the body. Think about how quickly all this happens. It has to be really fast, otherwise Michelle would not have been able to react. What would happen if a car pulled out unexpectedly in front of Michelle? A signal would have to go from her eyes to her brain and then to her muscles. What allows the nervous system to react so fast. It starts with the special cell of the nervous system, the neuron. "
which of the following is a role of the nervous system?,(A) To sense your surroundings with your eyes and other sense organs (B) To control your internal body systems and keep them in balance (C) To use language (D) think (E) learn (F) and remember (G) d all of the above,D,"Controlling muscles and maintaining balance are just two of the functions of the human nervous system. What else does the nervous system do? It senses the surrounding environment with sense organs that include the eyes and ears. It senses the bodys own internal environment, including its temperature. It controls internal body systems to make sure the body maintains homeostasis. It prepares the body to fight or flee in the case of an emergency. It allows thinking, learning, memory, and language. Remember Hakeem the skater from the first page of the chapter? When Hakeem started to fall off the railing, his nervous system sensed that he was losing his balance. It responded by sending messages to his muscles. Some muscles contracted while other relaxed. As a result, Hakeem gained his balance again. How did his nervous system accomplish all of this in just a split second? You need to know how the nervous system transmits messages to answer that question. "
what are the two main organs of the nervous system?,(A) the heart and brain (B) the brain and spinal cord (C) the spinal cord and the nerves (D) the brain and nerves,B,"The nervous system has two main parts, called the central nervous system and the peripheral nervous system. The peripheral nervous system is described later in this lesson. The central nervous system is shown in Figure 20.4. It includes the brain and spinal cord. "
which of the following are parts of the nervous system?,(A) your eyes and other sense organs (B) your heart (C) which beats faster in an emergency (D) c your skin (E) which senses the environment (F) d all of the above,A,"The nervous system has two main parts, called the central nervous system and the peripheral nervous system. The peripheral nervous system is described later in this lesson. The central nervous system is shown in Figure 20.4. It includes the brain and spinal cord. "
how does the nervous system help maintain homeostasis?,(A) The nervous system prepares your body to fight or flee (B) The nervous system senses the environment inside of your body (C) including (D) c The nervous system senses your surroundings (E) d all of the above,B,"Controlling muscles and maintaining balance are just two of the functions of the human nervous system. What else does the nervous system do? It senses the surrounding environment with sense organs that include the eyes and ears. It senses the bodys own internal environment, including its temperature. It controls internal body systems to make sure the body maintains homeostasis. It prepares the body to fight or flee in the case of an emergency. It allows thinking, learning, memory, and language. Remember Hakeem the skater from the first page of the chapter? When Hakeem started to fall off the railing, his nervous system sensed that he was losing his balance. It responded by sending messages to his muscles. Some muscles contracted while other relaxed. As a result, Hakeem gained his balance again. How did his nervous system accomplish all of this in just a split second? You need to know how the nervous system transmits messages to answer that question. "
all reproductive system disorders are caused by pathogens.,(A) true (B) false,B,"Many disorders of the reproductive system are not sexually transmitted infections. They are not caused by pathogens, so they dont spread from person to person. They develop for other reasons. The disorders are different between males and females. In both genders, the disorders could cause a little discomfort, or they could cause death. "
injuries to the testes most often occur while playing sports.,(A) true (B) false,A,"Most common disorders of the male reproductive system involve the testes. For example, injuries to the testes are very common. In teenagers, injuries to the testes most often occur while playing sports. An injury such as a strike or kick to the testes can be very painful. It may also cause bruising and swelling. Such injuries do not usually last very long. Another disorder of the testes is cancer. Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control. The cells form a lump called a tumor. If found early, cancer of the testes usually can be easily cured with surgery. "
this is one of the most common disorders in females.,(A) vaginitis (B) yeast infection (C) ovarian cyst (D) breast cancer,A,"Disorders of the female reproductive system may involve the vagina, uterus, or ovaries. They may also affect the breasts. Vaginitis is a very common disorder. Symptoms include redness and itching of the vagina. It may be caused by soap or bubble bath. Another possible cause is a yeast infection. Yeast normally grow in the vagina. If they multiple too quickly, they may cause irritation. A yeast infection can be treated with medication. Cysts may develop in the ovaries. A cyst is a sac filled with fluid or other material. Ovarian cysts are usually harmless and often disappear on their own. However, some cysts may be painful and require surgery. Many females experience abdominal cramps during menstruation. This is usually normal and not a cause for concern. Exercise, heat, or medication may help relieve the pain. In severe cases, prescription medicine may be needed. Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery. "
cancer of the testes is most common in males aged,(A) 20 to 35 (B) 15 to 30 (C) 15 to 35 (D) 25 to 50,C,"Most common disorders of the male reproductive system involve the testes. They include injuries and cancer. Injuries to the testes are very common. In teens, such injuries occur most often while playing sports. Injuries to the testes are likely to be very painful and cause bruising and swelling. However, they generally subside fairly quickly. Cancer of the testes is most common in males aged 15 to 35. It occurs when cells in the testes grow out of control and form a tumor. If found early, cancer of the testes usually can be cured with surgery. "
painful menstrual periods can be eased with,(A) a warm bath or heating pad (B) exercise (C) pain relievers (D) all of the above,D,"Disorders of the female reproductive system may affect the vagina, uterus, or ovaries. They may also affect the breasts. One of the most common disorders is vaginitis. This is redness and itching of the vagina. It may be due to irritation by soap or bubble bath. Another possible cause of vaginitis is a yeast infection. Yeast normally grow in the vagina. A yeast infection happens when the yeast multiply too fast and cause symptoms. A yeast infection can be treated with medication. Bubble baths may be fun, but for women and girls they can cause irritation to the vagina. A common disorder of the ovaries is an ovarian cyst. A cyst is a sac filled with fluid or other material. An ovarian cyst is usually harmless, but it may cause pain. Most cysts slowly disappear and do not need treatment. Very large or painful cysts can be removed with surgery. Many teen girls have painful menstrual periods. They typically have cramping in the lower abdomen. Generally, this is nothing to worry about. Taking a warm bath or using a heating pad often helps. Exercise can help as well. A pain reliever like ibuprofen may also work. If the pain is severe, a doctor can prescribe stronger medicine to relieve the pain. The most common type of cancer in females is breast cancer. The cancer causes the cells of the breast to grow out of control and form a tumor. Breast cancer is rare in teens. It becomes more common as women get older. If breast cancer is found early, it usually can be cured with surgery. "
these disorders are serious and usually require surgery.,(A) large ovarian cysts (B) breast cancer (C) severe yeast infections (D) both (a,D,"Many disorders of the reproductive system are not sexually transmitted infections. They are not caused by pathogens, so they dont spread from person to person. They develop for other reasons. The disorders are different between males and females. In both genders, the disorders could cause a little discomfort, or they could cause death. "
disorders like vaginitis and ovarian cysts are passed from person to person through,(A) the blood (B) sexual contact (C) both of the above (D) They cannot be passed from person to person,D,"Disorders of the female reproductive system may involve the vagina, uterus, or ovaries. They may also affect the breasts. Vaginitis is a very common disorder. Symptoms include redness and itching of the vagina. It may be caused by soap or bubble bath. Another possible cause is a yeast infection. Yeast normally grow in the vagina. If they multiple too quickly, they may cause irritation. A yeast infection can be treated with medication. Cysts may develop in the ovaries. A cyst is a sac filled with fluid or other material. Ovarian cysts are usually harmless and often disappear on their own. However, some cysts may be painful and require surgery. Many females experience abdominal cramps during menstruation. This is usually normal and not a cause for concern. Exercise, heat, or medication may help relieve the pain. In severe cases, prescription medicine may be needed. Breast cancer is the most common type of cancer in females. It occurs when cells in the breast grow out of control and form a tumor. Breast cancer is rare in teens but becomes more common as females get older. Regular screening is recommended for most women starting around age 40. If found early, breast cancer usually can be cured with surgery. "
two main types of nonrenewable resources are fossil fuels and nuclear power.,(A) true (B) false,A,"Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the uranium needed for nuclear power will soon be used up if we continue to consume them at these rates. Using fossil fuels and nuclear energy creates other problems as well. The burning of fossil fuels releases carbon dioxide into the atmosphere. This is one of the major greenhouse gases causing global climate change. Nuclear power creates another set of problems, including the disposal of radioactive waste. "
"it is possible that by the year 2055, the worlds oil reserves will be gone.",(A) true (B) false,A,"Every 20 minutes, the human population adds 3,500 more people. More people need more resources. For example, we now use five times more fossil fuels than we did in 1970. The human population is expected to increase for at least 40 years. What will happen to resource use? "
nuclear energy is derived from,(A) uranium (B) helium (C) hydrogen (D) all of the above,A,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
what will help decrease the demand on natural resources?,(A) improvements in technology (B) controls in population growth (C) conservation of resources (D) all of the above,D,"Reducing the amount of natural resources you use is the best way to conserve resources. It takes energy to make new items, and even reusing or recycling items takes energy. You can reduce the amount of natural resources you use by not using the resources in the first place. Often, this involves just being less wasteful. Follow these tips to reduce your use of natural resources: Walk, bike, or use public transit instead of driving. If you must drive, a fuel-efficient vehicle will reduce energy use. Plan ahead to avoid making extra trips. Dont buy more than you need. For example, dont buy more fresh food than you can use without it going to waste. You will not only reduce your use of food. You will also reduce your use of energy resources. It takes a lot of energy to grow, process, and ship many of the foods we buy. When you shop, keep packaging in mind. ""Precycle"" by buying items with the least amount of wasted packaging. Use energy-efficient appliances and LED light bulbs. Also, turn off appliances and lights when you arent using them. Both steps will reduce the amount of energy resources you use. Keep the thermostat set low in the winter and high in the summer (see Figure 25.12). Instead of turning up the heat in cold weather, put on an extra layer of clothes to save energy resources. Open windows and use fans in hot weather rather than turning on the air conditioning. "
what countries have the highest energy consumption per person?,(A) China and India (B) the United States and England (C) the United States and Australia (D) the United States and Canada,C,"People in the richer nations of the world use far more energy, especially energy from fossil fuels, than people in the poorer nations do. Figure 17.23 compares the amounts of oil used by the top ten oil-consuming nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels a year. Because richer nations use more fossil fuels, they also cause more air pollution and global warming than poorer nations do. "
current fuel supplies for nuclear power will last only to about the year,(A) 2050 (B) 2100 (C) 2200 (D) 2250,B,"Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the uranium needed for nuclear power will soon be used up if we continue to consume them at these rates. Using fossil fuels and nuclear energy creates other problems as well. The burning of fossil fuels releases carbon dioxide into the atmosphere. This is one of the major greenhouse gases causing global climate change. Nuclear power creates another set of problems, including the disposal of radioactive waste. "
"oil took millions of years to form, but __________ years to completely use.",(A) less than 200 (B) 250 to 300 (C) about 500 (D) around 1 (E) 000,B,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
organic compounds are built around the element oxygen.,(A) true (B) false,B,"The main chemical components of living organisms are known as organic compounds. Organic compounds are molecules built around the element carbon (C). Living things are made up of very large molecules. These large molecules are called macromolecules because macro means large; they are made by smaller molecules bonding together. Our body gets these smaller molecules, the ""building blocks"" or monomers, of organic molecules from the food we eat. Which organic molecules do you recognize from the list below? The four main types of macromolecules found in living organisms, shown in Table 1.1, are: 1. 2. 3. 4. Proteins. Carbohydrates. Lipids. Nucleic Acids. Proteins C, H, O, N, S Enzymes, muscle fibers, antibodies Elements Examples Monomer building molecule) (small block Amino acids Carbohydrates C, H, O Sugar, glucose, starch, glycogen, cellulose Monosaccharides (simple sugars) Lipids C, H, O, P Fats, oils, waxes, steroids, phospho- lipids in membranes Often include fatty acids Nucleic Acids C, H, O, P, N DNA, RNA, ATP Nucleotides "
"fats and oils are lipids. at room temperature, oils are solid and fats are liquid.",(A) true (B) false,B,"Have you ever tried to put oil in water? They dont mix. Oil is a type of lipid. Lipids are molecules such as fats, oils, and waxes. The most common lipids in your diet are probably fats and oils. Fats are solid at room temperature, whereas oils are fluid. Animals use fats for long-term energy storage and to keep warm. Plants use oils for long- term energy storage. When preparing food, we often use animal fats, such as butter, or plant oils, such as olive oil or canola oil. There are many more type of lipids that are important to life. One of the most important are the phospholipids that make up the protective outer membrane of all cells ( Figure 1.5). These lipid membranes are impermeable to most water soluble compounds. "
proteins are organic compounds made of,(A) nucleotides (B) amino acids (C) polysaccharides (D) lipids,B,"Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. "
what organic compound makes up the cell membrane?,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids,B,"Molecules in the cell membrane allow it to be semipermeable. The membrane is made of a double layer of phospholipids (a ""bilayer"") and proteins ( Figure below). Recall that phospholipids, being lipids, do not mix with water. It is this quality that allows them to form the outside barrier of the cell. A single phospholipid molecule has two parts: 1. A polar head that is hydrophilic, or water-loving. 2. A fatty acid tail that is hydrophobic, or water-fearing. The cell membrane is made up of a phos- pholipid bilayer, two layers of phospho- lipid molecules. Notice the polar head group of the phospholipid is attached to the phosphate, and the tails are two fatty acid chains. The head group and tails are attached by a glycerol backbone. There is water found on both the inside and the outside of cells. Since hydrophilic means water-loving, and they want to be near water, the heads face the inside and outside of the cell where water is found. The water-fearing, hydrophobic tails face each other in the middle of the cell membrane, because water is not found in this space. The phospholipid bilayer allows the cell to stay intact in a water-based environment. An interesting quality of the plasma membrane is that it is very ""fluid"" and constantly moving, like a soap bubble. This fluid nature of the membrane is important in maintaining homeostasis. It allows the proteins in the membrane to float to areas where they are needed. Due to the composition of the cell membrane, small molecules such as oxygen and carbon dioxide can pass freely through the membrane, but other molecules, especially large molecules, cannot easily pass through the plasma membrane. These molecules need assistance to get across the membrane. That assistance will come in the form of transport proteins. "
which of the following are carbohydrates?,(A) sugar (B) glucose (C) steroids (D) b glycogen (E) cellulose (F) ATP (G) c glucose (H) glycogen (I) waxes (J) d sugar (K) glucose (L) starch,D,"Carbohydrates are nutrients that include sugars, starches, and fiber. There are two types of carbohydrates: simple and complex. Pictured below are some foods that are good sources of carbohydrates ( Figure 1.1). "
about how many unique proteins are in humans?,(A) 1 (B) 000 (C) b 10 (D) 000 (E) c 100 (F) 000 (G) d 1 (H) 000 (I) 000,C,"There are about 22,000 genes in every human cell. Does every human cell have the same genes? Yes. Does every human cell make the same proteins? No. In a multicellular organism, such as us, cells have specific functions because they have different proteins. They have different proteins because different genes are expressed in different cell types (which is known as gene expression). Imagine that all of your genes are ""turned off."" Each cell type only ""turns on"" (or expresses) the genes that have the code for the proteins it needs to use. So different cell types ""turn on"" different genes, allowing different proteins to be made. This gives different cell types different functions. Once a gene is expressed, the protein product of that gene is usually made. For this reason, gene expression and protein synthesis are often considered the same process. "
which of the following is a biological catalyst?,(A) enzyme (B) antibody (C) steroid (D) RNA,A,"Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions. Catalysts are not reactants, but they help reactants come together so they can react. You can see one way this happens in the animation at the URL below. By helping reactants come together, a catalyst decreases the activation energy needed to start a chemical reaction. This speeds up the reaction. Living things depend on catalysts to speed up many chemical reactions inside their cells. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take billions of years without it! "
there are only four types of tissue in the human body.,(A) true (B) false,A,"The four types of tissues make up all the organs of the human body. An organ is a structure composed of two or more types of tissues that work together to perform the same function. Examples of human organs include the skin, brain, lungs, kidneys, and heart. Consider the heart as an example. Figure 16.3 shows how all four tissue types work together to make the heart pump blood. "
a group of similar cells that work together is known as a organ.,(A) true (B) false,B,"While cells are the basic units of an organism, groups of cells can perform a job together. These cells are called specialized because they have a special job. Specialized cells can be organized into tissues. For example, your liver cells are organized into liver tissue. Your liver tissue is further organized into an organ, your liver. Organs are formed from two or more specialized tissues working together to perform a job. All organs, from your heart to your liver, are made up of an organized group of tissues. These organs are part of a larger system, the organ systems. For example, your brain works together with your spinal cord and other nerves to form the nervous system. This organ system must be organized with other organ systems, such as the circulatory system and the digestive system, for your body to work. Organ systems work together to form the entire organism. There are many levels of organization in living things ( Figure 1.4). Levels of organization, from the atom (smallest) to the organism (largest). Notice that organelles are inside a cell, and organs are inside an organ- ism. "
"which organ system provides protection from injury and water loss, and physical defense against infection by microorganisms?",(A) the lymphatic system (B) the immune system (C) the integumentary system (D) the urinary system,C,"The immune system is the body system that fights to protect the body from specific pathogens. It has a special response for each type of pathogen. The immune systems specific reaction to a pathogen is called an immune response. The immune system is shown in Figure 21.13. It includes several organs and a network of vessels that carry lymph. Lymph is a yellowish liquid that normally leaks out of tiny blood vessels into spaces between cells in tissues. When inflammation occurs, more lymph leaks into tissues, and the lymph is likely to contain pathogens. "
"which organ system collects, transfers, and processes information?",(A) the nervous system (B) the endocrine system (C) the reproductive system (D) the lymphatic system,A,"The sensory division of the peripheral nervous system carries messages from sense organs and internal organs to the central nervous system. For example, it carries messages about images from the eyes to the brain. Once the messages reach the brain, the brain interprets the information. "
"which organ system is composed of the trachea, larynx, pharynx, and lungs?",(A) the digestive system (B) the urinary system (C) the endocrine system (D) the respiratory system,D,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
which is associated with the reproductive system?,(A) the seminal vesicles (B) the fallopian tubes and ovaries (C) the production of gametes and sex hormones (D) All of the above are associated with the reproductive system,D,Other reproductive system disorders include injuries and noninfectious diseases. These are different in males and females. 
which is associated with the endocrine system?,(A) bone marrow (B) blood vessels (C) hormones that communicate between cells (D) All of the above are associated with the endocrine system,C,"The endocrine system is a system of glands that release chemical messenger molecules into the blood stream. The messenger molecules are called hormones. Hormones act slowly compared with the rapid transmission of electrical impulses of the nervous system. Endocrine hormones must travel through the bloodstream to the cells they control, and this takes time. On the other hand, because endocrine hormones are released into the bloodstream, they travel to cells everywhere in the body. For a good visual introduction to the endocrine system, watch this short video: http MEDIA Click image to the left or use the URL below. URL: "
early earth was full of gas like oxygen and carbon dioxide.,(A) true (B) false,B,"Earths first atmosphere was made of hydrogen and helium, the gases that were common in this region of the solar system as it was forming. Most of these gases were drawn into the center of the solar nebula to form the Sun. When Earth was new and very small, the solar wind blew off atmospheric gases that collected. If gases did collect, they were vaporized by impacts, especially from the impact that brought about the formation of the Moon. Eventually things started to settle down and gases began to collect. High heat in Earths early days meant that there were constant volcanic eruptions, which released gases from the mantle into the atmosphere (see opening image). Just as today, volcanic outgassing was a source of water vapor, carbon dioxide, small amounts of nitrogen, and other gases. Scientists have calculated that the amount of gas that collected to form the early atmosphere could not have come entirely from volcanic eruptions. Frequent impacts by asteroids and comets brought in gases and ices, including water, carbon dioxide, methane, ammonia, nitrogen, and other volatiles from elsewhere in the solar system (Figure Calculations also show that asteroids and comets cannot be responsible for all of the gases of the early atmosphere, so both impacts and outgassing were needed. "
organic compounds are needed to build cells.,(A) true (B) false,A,"The main chemical components of living organisms are known as organic compounds. Organic compounds are molecules built around the element carbon (C). Living things are made up of very large molecules. These large molecules are called macromolecules because macro means large; they are made by smaller molecules bonding together. Our body gets these smaller molecules, the ""building blocks"" or monomers, of organic molecules from the food we eat. Which organic molecules do you recognize from the list below? The four main types of macromolecules found in living organisms, shown in Table 1.1, are: 1. 2. 3. 4. Proteins. Carbohydrates. Lipids. Nucleic Acids. Proteins C, H, O, N, S Enzymes, muscle fibers, antibodies Elements Examples Monomer building molecule) (small block Amino acids Carbohydrates C, H, O Sugar, glucose, starch, glycogen, cellulose Monosaccharides (simple sugars) Lipids C, H, O, P Fats, oils, waxes, steroids, phospho- lipids in membranes Often include fatty acids Nucleic Acids C, H, O, P, N DNA, RNA, ATP Nucleotides "
which of the following was not present in early earth?,(A) nitrogen gas (B) carbon dioxide (C) water vapor (D) hydrogen sulfoxide,D,"When Earth formed 4.6 billion years ago, it would not have been called the water planet. There were no oceans then. In fact, there was no liquid water at all. Early Earth was too hot for liquid water to exist. Earths early years were spent as molten rock and metal. "
chemical reactions need energy. where did this energy come from?,(A) volcanic eruptions and lightning (B) volcanic eruptions and nuclear fusion (C) lightening and thunder (D) thunder and volcanic eruptions,A,"Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas wont occur without the spark of energy to begin the reaction. Q: Why is activation energy needed? Why wont a reaction occur without it? A: A reaction wont occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. "
what is needed to build proteins?,(A) amino acids (B) nucleotides (C) organic compounds (D) all of the above,A,"Proteins are molecules that have many different functions in living things. All proteins are made of monomers called amino acids ( Figure 1.2) that connect together like beads on a necklace ( Figure 1.3). There are only 20 common amino acids needed to build proteins. These amino acids form in thousands of different combinations, making about 100,000 or more unique proteins in humans. Proteins can differ in both the number and order of amino acids. It is the number and order of amino acids that determines the shape of the protein, and it is the shape (structure) of the protein that determines the unique function of the protein. Small proteins have just a few hundred amino acids. The largest proteins have more than 25,000 amino acids. This model shows the general structure of all amino acids. Only the side chain, R, varies from one amino acid to another. KEY: H = hydrogen, N = nitrogen, C = carbon, O = oxygen, R = variable side chain. Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as ""biological catalysts."" For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure 1.4). Muscle fibers are made mostly of protein. Its important for you and other animals to eat food with protein, because we cannot make certain amino acids on our own. You can get proteins from plant sources, such as beans, and from animal sources, like milk or meat. When you eat food with protein, your body breaks the proteins down into individual amino acids and uses them to build new proteins. You really are what you eat! "
how old is the earliest forms of life?,(A) at least 350 (B) 000 years old (C) b at least 35 million years old (D) c at least 35 billion years old (E) d over 5 billion years,C,There is good evidence that life has probably existed on Earth for most of Earths history. Fossils of blue-green algae found in Australia are the oldest fossils of life forms on Earth. They are at least 3.5 billion years old ( Figure 1.1). 
where did these ingredients for early molecules come from?,(A) water vapor (B) meteorites (C) volcanic gases (D) all of the above,D,"How did life begin? In order to answer this question, scientists need to know what kinds of materials were available at that time. We know that the ingredients for life were present at the beginning of Earths history. Scientists believe early Earth did not contain oxygen gas (photosynthesis had yet to evolve), but did contain other gases, including: nitrogen gas, carbon dioxide, carbon monoxide, water vapor, hydrogen sulfide. Some of the oldest fossils on Earth were found along the coast of Australia, similar to the area shown here. Where did these ingredients come from? Some chemicals were in water and volcanic gases ( Figure 1.2). Other chemicals would have come from meteorites in space. Energy to drive chemical reactions was provided by volcanic eruptions and lightning. Today, we have evidence that life on Earth came from random reactions between chem- ical compounds, which formed molecules, or groups of atoms bonded together. Small molecules, such as those present in the early atmosphere, can provide the components (including the elements C, H, N, O and S) to make larger molecules. These early molecules further reacted and eventually formed even larger molecules and organic compounds, such as amino acids (which combine to form proteins), and nucleotides (which form nucleic acids - RNA or DNA). These organic molecules eventually came together in the right combinations to form basic cells. The components that were necessary for the formation of the first cells are still being studied. How long did it take to develop the first life forms? As much as 1 billion years. Many scientists still study the origin of the first life forms because there are many questions left unanswered, such as, ""Did proteins or nucleic acids develop first?"" or ""What exactly were early Earths atmospheric conditions like?"" There is a lot of work still left to answer these and similar questions. Some clues to the origins of life on Earth come from studying the early life forms that developed in hot springs, such as the Grand Prismatic Spring at Yellowstone National Park. This spring is approxi- mately 250 feet deep and 300 feet wide. "
the burning of fossil fuels causes most air pollution.,(A) true (B) false,A,"Most air pollutants can be traced to the burning of fossil fuels. Fossil fuels are burned during many processes, including in power plants to create electricity, in factories to make machinery run, in power stoves and furnaces for heating, and in waste facilities. Perhaps one of the biggest uses of fossil fuels is in transportation. Fossil fuels are used in cars, trains, and planes. Air pollution can also be caused by agriculture, such as cattle ranching and the use of fertilizers and pesticides. Other sources of air pollution include the production of plastics, refrigerants, and aerosols, in nuclear power and defense, from landfills and mining, and from biological warfare. "
outdoor air pollution changes the natural characteristics of the atmosphere.,(A) true (B) false,A,"The major cause of outdoor air pollution is the burning of fossil fuels. Fossil fuels are burned in power plants, factories, motor vehicles, and home heating systems. Ranching and using chemicals such as fertilizers also cause outdoor air pollution. Erosion of soil in farm fields, mining activities, and construction sites adds dust particles to the air as well. Some specific outdoor air pollutants are described in Table 25.1. Air Pollutant Sulfur oxides Nitrogen oxides Carbon monoxide Carbon dioxide Particles (dust, smoke) Mercury Smog Ground-level ozone Source coal burning motor vehicle exhaust motor vehicle exhaust all fossil fuel burning wood and coal burning coal burning coal burning motor vehicle exhaust Problem acid rain acid rain poisoning global climate change respiratory problems nerve poisoning respiratory problems respiratory problems "
which of the following processes burns fossil fuels?,(A) within power plants to create electricity (B) within factories to operate machinery (C) within furnaces to generate heat (D) all of the above,D,"Burning fossil fuels releases many pollutants into the air. These pollutants include carbon monoxide, carbon dioxide, nitrogen dioxide, and sulfur dioxide. Motor vehicles account for almost half of fossil fuel use. Most vehicles run on gasoline, which comes from petroleum. Power plants and factories account for more than a quarter of fossil fuel use. Power plants burn fossil fuels to generate electricity. Factories burn fossil fuels to power machines. Homes and other buildings also burn fossil fuels. The energy they release is used for heating, cooking, and other purposes. "
acid rain is formed from,(A) the production of plastics (B) nuclear power and defense (C) coal-fired power plants (D) all of the above,C,"Acid rain is caused by sulfur and nitrogen oxides emanating from power plants or metal refineries. The smokestacks have been built tall so that pollutants dont sit over cities (Figure 1.1). As they move, these pollutants combine with water vapor to form sulfuric and nitric acids. The acid droplets form acid fog, rain, snow, or they may be deposited dry. Most typical is acid rain (Figure 1.2). "
where do most greenhouse gases come from?,(A) mostly from a lack of trees (B) mostly from burning fossil fuels (C) mostly from landfills and mining (D) mostly from sulfur oxides and nitrogen oxides,B,"Greenhouse gases include CO2 , H2 O, methane, O3 , nitrous oxides (NO and NO2 ), and chlorofluorocarbons (CFCs). All are a normal part of the atmosphere except CFCs. Table 1.1 shows how each greenhouse gas naturally enters the atmosphere. Greenhouse Gas Carbon dioxide Methane Nitrous oxide Ozone Chlorofluorocarbons Where It Comes From Respiration, volcanic eruptions, decomposition of plant material; burning of fossil fuels Decomposition of plant material under some condi- tions, biochemical reactions in stomachs Produced by bacteria Atmospheric processes Not naturally occurring; made by humans Different greenhouse gases have different abilities to trap heat. For example, one methane molecule traps 23 times as much heat as one CO2 molecule. One CFC-12 molecule (a type of CFC) traps 10,600 times as much heat as one CO2 . Still, CO2 is a very important greenhouse gas because it is much more abundant in the atmosphere. "
effects of a global temperature increase include,(A) species extinction (B) a rise in sea levels (C) an increase in extreme weather events (D) all of the above,D,"As greenhouse gases increase, changes will be more extreme. Oceans will become more acidic, making it more difficult for creatures with carbonate shells to grow, and that includes coral reefs. A study monitoring ocean acidity in the Pacific Northwest found ocean acidity increasing ten times faster than expected and 10% to 20% of shellfish (mussels) being replaced by acid-tolerant algae. Plant and animal species seeking cooler temperatures will need to move poleward 100 to 150 km (60 to 90 miles) or upward 150 m (500 feet) for each 1.0o C (8o F) rise in global temperature. There will be a tremendous loss of biodiversity because forest species cant migrate that rapidly. Biologists have already documented the extinction of high-altitude species that have nowhere higher to go. Decreased snow packs, shrinking glaciers, and the earlier arrival of spring will all lessen the amount of water available in some regions of the world, including the western United States and much of Asia. Ice will continue to melt and sea level is predicted to rise 18 to 97 cm (7 to 38 inches) by 2100 (Figure 1.3). An increase this large will gradually flood coastal regions, where about one-third of the worlds population lives, forcing billions of people to move inland. Sea ice thickness around the North Pole has been decreasing in recent decades and will continue to decrease in the com- ing decades. Weather will become more extreme, with more frequent and more intense heat waves and droughts. Some modelers predict that the midwestern United States will become too dry to support agriculture and that Canada will become the new breadbasket. In all, about 10% to 50% of current cropland worldwide may become unusable if CO2 doubles. You may notice that the numerical predictions above contain wide ranges. Sea level, for example, is expected to rise somewhere between 18 and 97 cm  quite a wide range. What is the reason for this uncertainty? It is partly because scientists cannot predict exactly how the Earth will respond to increased levels of greenhouses gases. How quickly greenhouse gases continue to build up in the atmosphere depends in part on the choices we make. An important question people ask is this: Are the increases in global temperature natural? In other words, can natural variations in temperature account for the increase in temperature that we see? The answer is no. Changes in the Suns irradiance, El Nio and La Nia cycles, natural changes in greenhouse gas, and other atmospheric gases cannot account for the increase in temperature that has already happened in the past decades. Along with the rest of the worlds oceans, San Francisco Bay is rising. Changes are happening slowly in the coastal arena of the San Francisco Bay Area and even the most optimistic estimates about how high and how quickly this rise will occur indicate potentially huge problems for the region. Click image to the left or use the URL below. URL: "
which of the following is a source of air pollution?,(A) the production of aerosols (B) biological warfare (C) cattle ranching (D) all of the above,D,"Most air pollutants can be traced to the burning of fossil fuels. Fossil fuels are burned during many processes, including in power plants to create electricity, in factories to make machinery run, in power stoves and furnaces for heating, and in waste facilities. Perhaps one of the biggest uses of fossil fuels is in transportation. Fossil fuels are used in cars, trains, and planes. Air pollution can also be caused by agriculture, such as cattle ranching and the use of fertilizers and pesticides. Other sources of air pollution include the production of plastics, refrigerants, and aerosols, in nuclear power and defense, from landfills and mining, and from biological warfare. "
an infectious disease is contagious.,(A) true (B) false,A,"Has this ever happened to you? A student sitting next to you in class has a cold. The other student is coughing and sneezing, but you feel fine. Two days later, you come down with a cold, too. Diseases like colds are contagious. Contagious diseases are also called infectious diseases. An infectious disease is a disease that spreads from person to person. Infectious diseases are caused by pathogens. A pathogen is a living thing or virus that causes disease. Pathogens are commonly called germs. They can travel from one person to another. "
medicines called antibiotics can cure most diseases caused by viruses.,(A) true (B) false,B,"Living things that cause human diseases include bacteria, fungi, and protozoa. Most infectious diseases caused by these organisms can be cured with medicines. For example, medicines called antibiotics can cure most diseases caused by bacteria. Bacteria are one-celled organisms without a nucleus. Although most bacteria are harmless, some cause diseases. Worldwide, the most common disease caused by bacteria is tuberculosis (TB). TB is a serious disease of the lungs. Another common disease caused by bacteria is strep throat. You may have had strep throat yourself. Bacteria that cause strep throat are shown below ( Figure 1.1). Some types of pneumonia and many cases of illnesses from food are also caused by bacteria. The structures that look like strings of beads are bacteria. They belong to the genus Streptococcus. Bacteria of this genus cause diseases such as strep throat and pneumonia. They are shown here 900 times bigger than their actual size. Fungi are simple eukaryotic organisms that consist of one or more cells. They include mushrooms and yeasts. Human diseases caused by fungi include ringworm and athletes foot. Both are skin diseases that are not usually serious. A ringworm infection is pictured below ( Figure 1.2). A more serious fungus disease is histoplasmosis. It is a lung infection. Though fungal infections can be annoying, they are rarely as serious or deadly as bacterial or viral infections. Ringworm isnt a worm at all. Its a disease caused by a fungus. The fungus causes a ring-shaped rash on the skin, like the one shown here. Protozoa are one-celled organisms with a nucleus, making them eukaryotic organisms. They cause diseases such as malaria. Malaria is a serious disease that is common in warm climates. The protozoa infect people when they are bit by a mosquito. More than a million people die of malaria each year. Other protozoa cause diarrhea. An example is Giardia lamblia ( Figure 1.3). Viruses are nonliving collections of protein and DNA that must reproduce inside of living cells. Viruses cause many common diseases. For example, viruses cause colds and the flu. Cold sores are caused by the virus Herpes simplex This picture shows a one-celled organism called Giardia lamblia. It is a protozoan that causes diarrhea. ( Figure 1.4). Antibiotics do not affect viruses, because antibiotics only kill bacteria. But medicines called antiviral drugs can treat many diseases caused by viruses. Keep in mind that viruses are nonliving, so can they be killed? "
two diseases caused by fungi include,(A) ringworm and athlete’s foot (B) strep throat and pneumonia (C) malaria and diarrhea (D) tuberculosis and Giardia,A,"Several common human diseases are caused by fungi. They include ringworm and athletes foot, both shown in Figure 9.15. Ringworm isnt caused by a worm. Its a skin infection by a fungus that leads to a ring-shaped rash. The rash may occur on the head, neck, trunk, arms, or legs. Athletes foot is caused by the same fungus as ringworm. But in athletes foot, the fungus infects the skin between the toes. Athletes foot is the second most common skin disease in the U.S. "
what skin disease can be transferred from the floor of a public shower?,(A) impetigo (B) acne (C) athlete’s foot (D) all of the above,C,"Other pathogens spread when they get on objects or surfaces. A fungus may spread in this way. For example, you can pick up the fungus that causes athletes foot by wearing shoes that an infected person has worn. You can also pick up this fungus from the floor of a public shower or other damp areas. After acne, athletes foot is the most common skin disease in the United States. Therefore, the chance of coming in contact with the fungus in one of these ways is fairly high. Bacteria that cause the skin disease impetigo, which causes blisters, can spread when people share towels or clothes. The bacteria can also spread through direct skin contact in sports like wrestling. "
what disease can be spread by mosquitoes?,(A) malaria (B) Dengue Fever (C) West Nile virus (D) all of the above,D,"Still other pathogens are spread by vectors. A vector is an organism that carries pathogens from one person or animal to another. Most vectors are insects, such as ticks and mosquitoes. These insects tend to transfer protozoan or viral parasites. When an insect bites an infected person or animal, it picks up the pathogen. Then the pathogen travels to the next person or animal it bites. Ticks carry the bacteria that cause Lyme disease. Mosquitoes ( Figure serious symptoms may develop. Other diseases spread by mosquitoes include Dengue Fever and Yellow Fever. The first case of West Nile virus in North America occurred in 1999. Within just a few years, the virus had spread throughout most of the United States. Birds as well as humans can be infected with the virus. Birds often fly long distances. This is one reason why West Nile virus spread so quickly. "
diseases caused by a virus include,(A) the flu and common cold (B) athlete’s foot and the flu (C) malaria and ringworm (D) all of the above,A,"Viruses cause many human diseases. In addition to the flu and the common cold, viruses cause rabies, diarrheal diseases, AIDS, cold sores, and many other diseases ( Figure 1.2). Viral diseases range from mild to fatal. Cold sores are caused by a herpes virus. "
giardia lamblia is,(A) virus (B) bacterium (C) protozoa (D) fungi,C,"Roundworms can be free-living organisms, but they are probably best known for their role as significant plant and animal parasites. Most Nematodes are parasitic, with over 16,000 parasitic species described. Heartworms, which cause serious disease in dogs while living in the heart and blood vessels, are a type of roundworm. Roundworms can also cause disease in humans. Elephantiasis, a disease characterized by the extreme swelling of the limbs ( Figure Most parasitic roundworm eggs or larvae are found in the soil and enter the human body when a person picks them up on the hands and then transfers them to the mouth. The eggs or larvae also can enter the human body directly through the skin. The best solution to these diseases is to try to prevent these diseases rather than treat or cure them. Diseases caused by roundworms are more common in developing countries. Many parasitic diseases caused by roundworms result from poor personal hygiene. Contributing factors may include lack of a clean water supply, inadequate sanitation measures, crowded living conditions, combined with a lack of access to health care and low levels of education. "
a pedigree shows family relationships.,(A) true (B) false,A,"A pedigree is a chart that shows the inheritance of a trait over several generations. A pedigree is commonly created for families, and it outlines the inheritance patterns of genetic disorders and traits. A pedigree can help predict the probability that offspring will inherit a genetic disorder. Pictured below is a pedigree displaying recessive inheritance of a disorder through three generations ( Figure 1.1). From studying a pedigree, scientists can determine the following: If the trait is sex-linked (on the X or Y chromosome) or autosomal (on a chromosome that does not determine sex). If the trait is inherited in a dominant or recessive fashion. Sometimes pedigrees can also help determine whether individuals with the trait are heterozygous (two different alleles) or homozygous (two of the same allele). Some points to keep in mind when analyzing a pedigree are: 1. With autosomal recessive inheritance, all affected individuals will be homozygous recessive. 2. With dominant inheritance, all affected individuals will have at least one dominant allele. They will be either homozygous dominant or heterozygous. 3. With sex-linked inheritance, more males (XY) than females (XX) usually have the trait. Sex-linked inheritance is usually recessive. "
a pedigree can be useful in understanding inheritance.,(A) true (B) false,A,"A pedigree is a chart that shows the inheritance of a trait over several generations. A pedigree is commonly created for families, and it outlines the inheritance patterns of genetic disorders and traits. A pedigree can help predict the probability that offspring will inherit a genetic disorder. Pictured below is a pedigree displaying recessive inheritance of a disorder through three generations ( Figure 1.1). From studying a pedigree, scientists can determine the following: If the trait is sex-linked (on the X or Y chromosome) or autosomal (on a chromosome that does not determine sex). If the trait is inherited in a dominant or recessive fashion. Sometimes pedigrees can also help determine whether individuals with the trait are heterozygous (two different alleles) or homozygous (two of the same allele). Some points to keep in mind when analyzing a pedigree are: 1. With autosomal recessive inheritance, all affected individuals will be homozygous recessive. 2. With dominant inheritance, all affected individuals will have at least one dominant allele. They will be either homozygous dominant or heterozygous. 3. With sex-linked inheritance, more males (XY) than females (XX) usually have the trait. Sex-linked inheritance is usually recessive. "
"in autosomal recessive inheritance, all children of an couple with both parents having the recessive trait",(A) will not have the trait (B) will all have the trait (C) may or may not have the trait (D) Cannot be determined from the information given,B,"Some genetic disorders are caused by recessive alleles of a single gene on an autosome. An example of autosomal recessive genetic disorders are Tay-Sachs disease and cystic fibrosis. Children with cystic fibrosis have excessively thick mucus in their lungs, which makes it difficult for them to breathe. The inheritance of this recessive allele is the same as any other recessive allele, so a Punnett square can be used to predict the probability that two carriers of the disease will have a child with cystic fibrosis. Recall that carriers have the recessive allele for a trait but do not express the trait. What are the possible genotypes of the offspring in the following table ( Table 1.1)? What are the possible phenotypes? F FF (normal) Ff (carrier) F f f Ff (carrier) ff (affected) According to this Punnett square, two parents that are carriers (Ff ) of the cystic fibrosis gene have a 25% chance of having a child with cystic fibrosis (ff ). The affected child must inherit two recessive alleles. The carrier parents are not affected. Tay-Sachs disease is a severe genetic disorder in which affected children do not live to adulthood, so the gene is not passed from an affected individual. Carriers of the Tay-Sachs gene are not affected. How does a child become affected with Tay-Sachs? "
"in autosomal dominant inheritance, a homozygous dominant affected father will have children",(A) that may or may not be affected (B) that are not affected (C) that are all affected (D) Cannot tell from the information given,C,"Huntingtons disease is an example of an autosomal dominant disorder. This means that if the dominant allele is present, then the person will express the disease. A child only has to inherit one dominant allele to have the disease. The disease causes the brains cells to break down, leading to muscle spasms and personality changes. Unlike most other genetic disorders, the symptoms usually do not become apparent until middle age. You can use a simple Punnett square to predict the inheritance of a dominant autosomal disorder, like Huntingtons disease. If one parent has Huntingtons disease, what is the chance of passing it on to the children? If you draw the Punnett square, you will find that there is a 50 percent chance of the disorder being passed on to the children. "
"in sex-linked inheritance, the pedigree will most likely show",(A) more affected males (B) more affected females (C) an equal number of affected males and females (D) no affected individuals,A,"A pedigree is a chart that shows the inheritance of a trait over several generations. A pedigree is commonly created for families, and it outlines the inheritance patterns of genetic disorders and traits. A pedigree can help predict the probability that offspring will inherit a genetic disorder. Pictured below is a pedigree displaying recessive inheritance of a disorder through three generations ( Figure 1.1). From studying a pedigree, scientists can determine the following: If the trait is sex-linked (on the X or Y chromosome) or autosomal (on a chromosome that does not determine sex). If the trait is inherited in a dominant or recessive fashion. Sometimes pedigrees can also help determine whether individuals with the trait are heterozygous (two different alleles) or homozygous (two of the same allele). Some points to keep in mind when analyzing a pedigree are: 1. With autosomal recessive inheritance, all affected individuals will be homozygous recessive. 2. With dominant inheritance, all affected individuals will have at least one dominant allele. They will be either homozygous dominant or heterozygous. 3. With sex-linked inheritance, more males (XY) than females (XX) usually have the trait. Sex-linked inheritance is usually recessive. "
"in autosomal recessive inheritance, all affected individuals",(A) will be heterozygous (B) will be heterozygous recessive (C) will be homozygous dominant (D) will be homozygous recessive,D,"Since natural selection acts on the phenotype, if an allele causes death in a homozygous individual, aa, for example, it will not cause death in a heterozygous Aa individual. These heterozygous Aa individuals will then act as carriers of the a allele, meaning that the a allele could be passed down to offspring. People who are carriers do not express the recessive phenotype, as they have a dominant allele. This allele is said to be kept in the populations gene pool. The gene pool is the complete set of genes and alleles within a population. For example, Tay-Sachs disease is a recessive human genetic disorder. That means only individuals with the homozygous recessive genotype, rr will be affected. Affected individuals usually die from complications of the disease in early childhood, at an age too young to reproduce. The two parents are each heterozygous (Rr) for the Tay-Sachs gene; they will not die in childhood and will be carriers of the disease gene. This deadly allele is kept in the gene pool even though it does not help humans adapt to their environment. This happens because evolution acts on the phenotype, not the genotype ( Figure 1.1). Tay-Sachs disease is inherited in the au- tosomal recessive pattern. Each parent is an unaffected carrier of the lethal allele. "
"in autosomal dominant inheritance, all affected individuals",(A) will be homozygous dominant or heterozygous (B) will be homozygous recessive or heterozygous (C) will be heterozygous (D) Cannot be determined from the information given,A,"Huntingtons disease is an example of an autosomal dominant disorder. This means that if the dominant allele is present, then the person will express the disease. A child only has to inherit one dominant allele to have the disease. The disease causes the brains cells to break down, leading to muscle spasms and personality changes. Unlike most other genetic disorders, the symptoms usually do not become apparent until middle age. You can use a simple Punnett square to predict the inheritance of a dominant autosomal disorder, like Huntingtons disease. If one parent has Huntingtons disease, what is the chance of passing it on to the children? If you draw the Punnett square, you will find that there is a 50 percent chance of the disorder being passed on to the children. "
there are nerves that send and receive messages to the internal organs.,(A) true (B) false,A,"The motor division of the peripheral system carries messages from the central nervous system to internal organs and muscles. The motor division is also divided into two parts ( Figure 1.2), the somatic nervous system and the autonomic nervous system. The somatic nervous system carries messages that control body movements. It is responsible for activities that are under your control, such as waving your hand or kicking a ball. The girl pictured below ( Figure 1.4) is using her somatic nervous system to control the muscles needed to play the violin. Her brain sends messages to motor neurons that move her hands so she can play. Without the messages from her brain, she would not be able to move her hands and play the violin. The autonomic nervous system carries nerve impulses to internal organs. It controls activities that are not under your control, such as sweating and digesting food. The autonomic nervous system has two parts: 1. The sympathetic division controls internal organs and glands during emergencies. It prepares the body for fight or flight ( Figure 1.5). For example, it increases the heart rate and the flow of blood to the legs, so you can run away from danger. 2. The parasympathetic division controls internal organs and glands during the rest of the time. It controls processes like digestion, heartbeat, and breathing when there is not an emergency. Have you ever become frightened and felt your heart start pounding? How does this happen? The answer is your autonomic nervous system. The sympathetic division prepared you to deal with a possible emergency by increasing "
the peripheral nervous system sends messages along nerves from the brain to the spinal cord.,(A) true (B) false,B,"The spinal cord is a long, tube-shaped bundle of neurons. It runs from the brain stem to the lower back. The main job of the spinal cord is to carry nerve impulses back and forth between the body and brain. The spinal cord is like a two-way road. Messages about the body, both inside and out, pass through the spinal cord to the brain. Messages from the brain pass in the other direction through the spinal cord to tell the body what to do. "
which part of the pns carries messages from internal organs to the cns?,(A) the sensory division (B) the motor division (C) the somatic nervous system (D) the autonomic nervous system,A,"The sensory division of the peripheral nervous system carries messages from sense organs and internal organs to the central nervous system. For example, it carries messages about images from the eyes to the brain. Once the messages reach the brain, the brain interprets the information. "
which part of the pns controls involuntary activities such as activities such as digestion?,(A) the sensory division (B) the motor division (C) the somatic nervous system (D) the autonomic nervous system,D,"The motor division of the peripheral system carries messages from the central nervous system to internal organs and muscles. The motor division is also divided into two parts ( Figure 1.2), the somatic nervous system and the autonomic nervous system. The somatic nervous system carries messages that control body movements. It is responsible for activities that are under your control, such as waving your hand or kicking a ball. The girl pictured below ( Figure 1.4) is using her somatic nervous system to control the muscles needed to play the violin. Her brain sends messages to motor neurons that move her hands so she can play. Without the messages from her brain, she would not be able to move her hands and play the violin. The autonomic nervous system carries nerve impulses to internal organs. It controls activities that are not under your control, such as sweating and digesting food. The autonomic nervous system has two parts: 1. The sympathetic division controls internal organs and glands during emergencies. It prepares the body for fight or flight ( Figure 1.5). For example, it increases the heart rate and the flow of blood to the legs, so you can run away from danger. 2. The parasympathetic division controls internal organs and glands during the rest of the time. It controls processes like digestion, heartbeat, and breathing when there is not an emergency. Have you ever become frightened and felt your heart start pounding? How does this happen? The answer is your autonomic nervous system. The sympathetic division prepared you to deal with a possible emergency by increasing "
what part of the pns allows you to circle the correct answer to this question?,(A) the somatic nervous system (B) the autonomic nervous system (C) the sympathetic division (D) the parasympathetic division,A,"There are other nerves in your body that are not found in the brain or spinal cord. The peripheral nervous system (PNS) ( Figure 1.1) contains all the nerves in the body that are found outside of the central nervous system. They include nerves of the hands, arms, feet, legs, and trunk. They also include nerves of the scalp, neck, and face. Nerves that send and receive messages to the internal organs are also part of the peripheral nervous system. The peripheral nervous system is divided into two parts, the sensory division and the motor division. How these divisions of the peripheral nervous system are related to the rest of the nervous system is shown below ( Figure 1.2). Refer to the figure as you read more about the peripheral nervous system in the text that follows. "
what part of the pns increases the heart rate in an emergency situation?,(A) the sensory division (B) the motor division (C) the sympathetic division (D) the parasympathetic division,C,"There are other nerves in your body that are not found in the brain or spinal cord. The peripheral nervous system (PNS) ( Figure 1.1) contains all the nerves in the body that are found outside of the central nervous system. They include nerves of the hands, arms, feet, legs, and trunk. They also include nerves of the scalp, neck, and face. Nerves that send and receive messages to the internal organs are also part of the peripheral nervous system. The peripheral nervous system is divided into two parts, the sensory division and the motor division. How these divisions of the peripheral nervous system are related to the rest of the nervous system is shown below ( Figure 1.2). Refer to the figure as you read more about the peripheral nervous system in the text that follows. "
what part of the nervous system tells you that cookies are being baked?,(A) the central nervous system (B) the sensory division (C) the autonomic nervous system (D) the somatic nervous system,A,"Controlling muscles and maintaining balance are just two of the functions of the human nervous system. What else does the nervous system do? It senses the surrounding environment with sense organs that include the eyes and ears. It senses the bodys own internal environment, including its temperature. It controls internal body systems to make sure the body maintains homeostasis. It prepares the body to fight or flee in the case of an emergency. It allows thinking, learning, memory, and language. Remember Hakeem the skater from the first page of the chapter? When Hakeem started to fall off the railing, his nervous system sensed that he was losing his balance. It responded by sending messages to his muscles. Some muscles contracted while other relaxed. As a result, Hakeem gained his balance again. How did his nervous system accomplish all of this in just a split second? You need to know how the nervous system transmits messages to answer that question. "
glucose is the food of plants.,(A) true (B) false,A,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
glucose is the main product of photosynthesis.,(A) true (B) false,A,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
which statement best describes a producer?,(A) An organism that produces food for itself and other organisms (B) An organism that produces complex organic compounds from simple inorganic molecules (C) An organism that obtains carbon from outside sources (D) All plants are producers,A,"Producers are living things that use energy to make food. Producers make food for themselves and other living things. There are two types of producers: By far the most common producers use the energy in sunlight to make food. This is called photosynthesis. Producers that photosynthesize include plants and algae. These organisms must live where there is plenty of sunlight. Which living things are producers in Figure 18.3? Other producers use the energy in chemicals to make food. This is called chemosynthesis. Only a very few producers are of this type, and all of them are microbes. These producers live deep under the ocean where there is no sunlight. You can see an example in Figure 18.4. "
which statement best describes an autotroph?,(A) An organism that produces food for itself an other organisms (B) An organism that produces complex organic compounds from simple (C) An organism that obtains carbon from outside sources (D) All plants are autotrophs,B,"Producers are living things that produce food for themselves and other organisms. They use energy and simple inorganic molecules to make organic compounds. Producers are vital to all ecosystems because all organisms need organic compounds for energy. Producers are also called autotrophs. There are two basic types of autotrophs: photoautotrophs and chemoautotrophs. Photoautotrophs use energy in sunlight to make organic compounds by photosynthesis. They include plants, algae, and some bacteria (see Figure 24.1). Chemoautotrophs use energy in chemical compounds to make organic compounds. This process is called chemosynthesis. Chemoautotrophs include certain bacteria and archaea. "
"which best summarized photosynthesis? in the presence of sunlight,",(A) carbon dioxide + oxygen → glucose + water (B) glucose + oxygen → carbon dioxide + water (C) carbon dioxide + water → glucose + oxygen (D) carbon dioxide + glucose → oxygen + water,C,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
what is the organelle of photosynthesis?,(A) the mitochondria (B) the chloroplast (C) the nucleus (D) the endoplasmic reticulum,B,"Photosynthesis takes place in the organelle of the plant cell known as the chloroplasts. Chloroplasts are one of the main differences between plant and animal cells. Animal cells do not have chloroplasts, so they cannot photosynthesize. Photosynthesis occurs in two stages. During the first stage, the energy from sunlight is absorbed by the chloroplast. Water is used, and oxygen is produced during this part of the process. During the second stage, carbon dioxide is used, and glucose is produced. Chloroplasts contain stacks of thylakoids, which are flattened sacs of membrane. Energy from sunlight is absorbed by the pigment chlorophyll in the thylakoid membrane. There are two separate parts of a chloroplast: the space inside the chloroplast itself, and the space inside the thylakoids ( Figure 1.1). The inner compartments inside the thylakoids are called the thylakoid space (or lumen). This is the site of the first part of photosynthesis. The interior space that surrounds the thylakoids is filled with a fluid called stroma. This is where carbon dioxide is used to produce glucose, the second part of photosynthesis. The chloroplast is the photosynthesis fac- tory of the plant. "
"as almost all organisms on earth obtain their energy from photosynthetic organisms, it could be said that ultimately all energy comes from _________.",(A) plants (B) food (C) the sun (D) carbon dioxide,C,"Energy is the ability to do work. In organisms, this work can be physical work, like walking or jumping, or it can be the work used to carry out the chemical processes in their cells. Every biochemical reaction that occurs in an organisms cells needs energy. All organisms need a constant supply of energy to stay alive. Some organisms can get the energy directly from the sun. Other organisms get their energy from other organisms. Through predator-prey relationships, the energy of one organism is passed on to another. Energy is constantly flowing through a community. With just a few exceptions, all life on Earth depends on the suns energy for survival. The energy of the sun is first captured by producers ( Figure 1.1), organisms that can make their own food. Many producers make their own food through the process of photosynthesis. The ""food"" the producers make is the sugar, glucose. Producers make food for the rest of the ecosystem. As energy is not recycled, energy must consistently be captured by producers. This energy is then passed on to the organisms that eat the producers, and then to the organisms that eat those organisms, and so on. Recall that the only required ingredients needed for photosynthesis are sunlight, carbon dioxide (CO2 ), and wa- ter (H2 O). From these simple inorganic ingredients, photosynthetic organisms produce the carbohydrate glucose (C6 H12 O6 ), and other complex organic compounds. Essentially, these producers are changing the energy from the sunlight into a usable form of energy. They are also making the oxygen that we breathe. Oxygen is a waste product of photosynthesis. The survival of every ecosystem is dependent on the producers. Without producers capturing the energy from the sun and turning it into glucose, an ecosystem could not exist. On land, plants are the dominant producers. Phytoplankton, tiny photosynthetic organisms, are the most common producers in the oceans and lakes. Algae, which is the green layer you might see floating on a pond, are an example of phytoplankton. There are also bacteria that use chemical processes to produce food. They get their energy from sources other than the sun, but they are still called producers. This process is known as chemosynthesis, and is common in ecosystems without sunlight, such as certain marine ecosystems. Producers include (a) plants, (b) algae, and (c) diatoms. "
phenotypes associated with polygenic traits can be represented by a bell-shaped curve.,(A) true (B) false,A,"Another exception to Mendels rules is polygenic inheritance, which occurs when a trait is controlled by more than one gene. This means that each dominant allele ""adds"" to the expression of the next dominant allele. Usually, traits are polygenic when there is wide variation in the trait. For example, humans can be many different sizes. Height is a polygenic trait, controlled by at least three genes with six alleles. If you are dominant for all of the alleles for height, then you will be very tall. There is also a wide range of skin color across people. Skin color is also a polygenic trait, as are hair and eye color. Polygenic inheritance often results in a bell shaped curve when you analyze the population ( Figure 1.1). That means that most people fall in the middle of the phenotypic range, such as average height, while very few people are at the extremes, such as very tall or very short. At one end of the curve will be individuals who are recessive for all the alleles (for example, aabbcc); at the other end will be individuals who are dominant for all the alleles (for example, AABBCC). Through the middle of the curve will be individuals who have a combination of dominant and recessive alleles (for example, AaBbCc or AaBBcc). "
polygenic traits demonstrate a wide variation in the phenotype.,(A) true (B) false,A,Some traits are controlled by more than one gene. They are called polygenic traits. Each gene for a polygenic trait may have two or more alleles. The genes may be on the same or different chromosomes. Polygenic traits may have many possible phenotypes. Skin color and adult height are examples of polygenic traits in humans. Think about all the variation in the heights of adults you know. Normal adults may range from less than 5 feet tall to more than 7 feet tall. There are people at every gradation of height in between these extremes. 
"if a, b and c represent dominant alleles of a polygenic trait, what genotype will represent an extreme phenotype?",(A) AaBbCc (B) AABbcc (C) AABBCC (D) AabbcC,A,"You know that the B allele is dominant to the b allele. Therefore, you can also use the Punnett square in Figure 6.8 to predict the most likely offspring phonotypes. If the parents had four offspring, their most likely phenotypes would be three with purple flowers (1 BB + 2 Bb) and one with white flowers (1 bb). "
"if a, b and c represent dominant alleles of a polygenic trait, what genotype will represent the moderate (or middle) phenotype?",(A) AaBbCc (B) AAbbcc (C) AaBBCc (D) All of the above represent moderate phenotypes,A,"You know that the B allele is dominant to the b allele. Therefore, you can also use the Punnett square in Figure 6.8 to predict the most likely offspring phonotypes. If the parents had four offspring, their most likely phenotypes would be three with purple flowers (1 BB + 2 Bb) and one with white flowers (1 bb). "
which genotype will have a more extreme phenotype?,(A) AaBbCc (B) AABbcc (C) aaBbCC (D) All of the above will show very similar phenotypes,D,"The expression of an organisms genotype is called its phenotype. The phenotype refers to the organisms traits, such as purple or white flowers. Different genotypes may produce the same phenotype. This will be the case if one allele is dominant to the other. Both BB and Bb genotypes in Table 6.1 have purple flowers. Thats because the B allele is dominant to the b allele, which is recessive. The terms dominant and recessive are the terms Mendel used to describe his ""factors."" Today we use them to describe alleles. In a Bb heterozygote, only the dominant B allele is expressed. The recessive b allele is expressed only in the bb genotype. "
"human height is a polygenic trait. if individuals with more dominant alleles are tall, what will be the genotype of a professional basketball player.",(A) nnbbaa (B) NnBbAa (C) NNBBaa (D) NNBBAA,A,Some traits are controlled by more than one gene. They are called polygenic traits. Each gene for a polygenic trait may have two or more alleles. The genes may be on the same or different chromosomes. Polygenic traits may have many possible phenotypes. Skin color and adult height are examples of polygenic traits in humans. Think about all the variation in the heights of adults you know. Normal adults may range from less than 5 feet tall to more than 7 feet tall. There are people at every gradation of height in between these extremes. 
"in addition to skin color and height, which of the following is also a polygenic trait?",(A) freckles (B) hair color (C) eye size (D) both (b,B,Some traits are controlled by more than one gene. They are called polygenic traits. Each gene for a polygenic trait may have two or more alleles. The genes may be on the same or different chromosomes. Polygenic traits may have many possible phenotypes. Skin color and adult height are examples of polygenic traits in humans. Think about all the variation in the heights of adults you know. Normal adults may range from less than 5 feet tall to more than 7 feet tall. There are people at every gradation of height in between these extremes. 
"many birds are altricial organisms, needing a lot of parental care.",(A) true (B) false,A,"In birds, 90% to 95% of species are monogamous, meaning the male and female remain together for breeding for a few years or until one mate dies. Birds of all types, from parrots to eagles and falcons, are monogamous. Usually, the parents take turns incubating the eggs. Birds usually incubate their eggs after the last one has been laid. In polygamous species, where there is more than one mate, one parent does all of the incubating. The wild turkey is an example of a polygamous bird. The length and type of parental care varies widely amongst different species of birds. At one extreme, in a group of birds called the magapodes (which are chicken-like birds), parental care ends at hatching. In this case, the newly- hatched chick digs itself out of the nest mound without parental help and can take care of itself right away. These birds are called precocial. Other precocial birds include the domestic chicken and many species of ducks and geese. At the other extreme, many seabirds care for their young for extended periods of time. For example, the chicks of the Great Frigatebird receive intensive parental care for six months, or until they are ready to fly, and then take an additional 14 months of being fed by the parents ( Figure 1.2). These birds are the opposite of precocial birds and are called altricial. In most animals, male parental care is rare. But it is very common in birds. Often both parents share tasks such as defense of territory and nest site, incubation, and the feeding of chicks. Since birds often take great care of their young, some birds have evolved a behavior called brood parasitism. This happens when a bird leaves her eggs in another birds nest. The host bird often accepts and raises the parasite birds eggs. Great Frigatebird adults are known to care for their young for up to 20 months after hatching, the longest in a bird species. Here, a young bird is begging for food. "
exponential growth requires an unlimited food supply.,(A) true (B) false,A,"Population growth can be described with two models, based on the size of the population and necessary resources. These two types of growth are known as exponential growth and logistic growth. If a population is given unlimited amounts of resources, such as food and water, land if needed, moisture, oxygen, and other environmental factors, it will grow exponentially. Exponential growth occurs as a population grows larger, dramatically increasing the growth rate. This is shown as a ""J-shaped"" curve below ( Figure 1.3). You can see that the population grows slowly at first, but as time passes, growth occurs more and more rapidly. Growth of populations according to ex- ponential (or J-curve) growth model (left) and logistic (or S-curve) growth model (right). Time is plotted on the x-axis, and population size is plotted on the y-axis. In nature, organisms do not usually have ideal environments with unlimited food. In nature, there are limits. Sometimes, there will be plenty of food. Sometimes, a fire will wipe out all of the available nutrients. Sometimes a predator will kill many individuals in a population. How do you think these limits affect the way organisms grow? "
which factor affects the population growth rate?,(A) The age of organisms at first reproduction (B) The age of an organism at death (C) The age of the newborn at birth (D) all of the above,A,"Population growth rate depends on birth rates and death rates, as well as migration. First, we will consider the effects of birth and death rates. You can predict the growth rate by using this simple equation: growth rate = birth rate death rate. If the birth rate is larger than the death rate, then the population grows. If the death rate is larger than the birth rate, what will happen to the population? The population size will decrease. If the birth and death rates are equal, then the population size will not change. Factors that affect population growth are: 1. 2. 3. 4. 5. 6. Age of organisms at first reproduction. How often an organism reproduces. The number of offspring of an organism. The presence or absence of parental care. How long an organism is able to reproduce. The death rate of offspring. For an ecosystem to be stable, populations in that system must be healthy, and that usually means reproducing as much as their environment allows. Do organisms reproduce yearly or every few years? Do organisms reproduce for much of their life, or just part of their life? Do organisms produce many offspring at once, or just a few, or even just one? Do many newborn organisms die, or do the majority survive? All these factors play a role in the growth of a population. Organisms can use different strategies to increase their reproduction rate. Altricial organisms are helpless at birth, and their parents give them a lot of care. This care is often seen in bird species. ( Figure 1.1). Altricial birds are usually born blind and without feathers. Compared to precocial organisms, altricial organisms have a longer period of development before they reach maturity. Precocial organisms, such as the geese shown below, can take care of themselves at birth and do not require help from their parents ( Figure 1.1). In order to reproduce as much as possible, altricial and precocial organisms must use very different strategies. (left) A hummingbird nest with young il- lustrates an altricial reproductive strategy, with a few small eggs, helpless young, and intensive parental care. (right) The Canada goose shows a precocial repro- ductive strategy. It lays a large number of large eggs, producing well-developed young. "
"if the death rate is larger than the birth rate, what will happen to the population?",(A) The population size will stay the same (B) The population size will increase (C) The population size will decrease (D) nothing will happen,C,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
what happens to population growth as resources become less available?,(A) logistic growth becomes exponential growth (B) exponential growth becomes logistic growth (C) exponential growth continues to the carrying capacity (D) logistic growth stops,B,"If there are 12 hamburgers at a lunch table and 24 people sit down at a lunch table, will everyone be able to eat? At first, maybe you will split hamburgers in half, but if more and more people keep coming to sit at the lunch table, you will not be able to feed everyone. This is what happens in nature. But in nature, organisms that cannot get food will die or find a new place to live. It is possible for any resource to be a limiting factor, however, a resource such as food can have dramatic consequences on a population. In nature, when the population size is small, there is usually plenty of food and other resources for each individual. When there is plenty of food and other resources, organisms can easily reproduce, so the birth rate is high. As the population increases, the food supply, or the supply of another necessary resource, may decrease. When necessary resources, such as food, decrease, some individuals will die. Overall, the population cannot reproduce at the same rate, so the birth rates drop. This will cause the population growth rate to decrease. When the population decreases to a certain level where every individual can get enough food and other resources, and the birth and death rates become stable, the population has leveled off at its carrying capacity. "
which of the following is true about altricial organisms?,(A) Altricial organisms require minimal parental support (B) Altricial birds are able to fly at birth (C) Altricial birds are usually born blind and without feathers (D) Altricial organisms reach maturity relatively quickly,C,"Many adaptations protect organisms from the external environment (Figure 1.2). Other adaptations help an organism move or gather food. Reindeer have sponge-like hoofs that help them walk on snowy ground without slipping and falling. Hummingbirds have long, thin beaks that help them drink nectar from flowers. Organisms have special features that help them avoid being eaten. When a herd of zebras run away from lions, the zebras dark stripes confuse the predators so that they have difficulty focusing on just one zebra during the chase. Some plants have poisonous or foul-tasting substances in them that keep animals from eating them. Their brightly colored flowers serve as a warning. There is an amazing diversity of organisms on Earth. How do the organisms in this picture each make their living? Cacti have thick, water- retaining bodies that help them conserve water. Poison dart frogs have toxins in their skin. Their bright colors warn potential predators not to take a bite! Thousands of northern elephant seals  some weighing up to 4,500 pounds  make an annual migration to breed each winter at Ao Nuevo State Reserve in California. Marine biologists are using high-tech tools to explore the secrets of these amazing creatures. Click image to the left or use the URL below. URL: "
which factor affects the population growth rate?,(A) The presence or absence of parental care (B) The death rate of offspring (C) How often an organism reproduces (D) all of the above,D,"Population growth rate depends on birth rates and death rates, as well as migration. First, we will consider the effects of birth and death rates. You can predict the growth rate by using this simple equation: growth rate = birth rate death rate. If the birth rate is larger than the death rate, then the population grows. If the death rate is larger than the birth rate, what will happen to the population? The population size will decrease. If the birth and death rates are equal, then the population size will not change. Factors that affect population growth are: 1. 2. 3. 4. 5. 6. Age of organisms at first reproduction. How often an organism reproduces. The number of offspring of an organism. The presence or absence of parental care. How long an organism is able to reproduce. The death rate of offspring. For an ecosystem to be stable, populations in that system must be healthy, and that usually means reproducing as much as their environment allows. Do organisms reproduce yearly or every few years? Do organisms reproduce for much of their life, or just part of their life? Do organisms produce many offspring at once, or just a few, or even just one? Do many newborn organisms die, or do the majority survive? All these factors play a role in the growth of a population. Organisms can use different strategies to increase their reproduction rate. Altricial organisms are helpless at birth, and their parents give them a lot of care. This care is often seen in bird species. ( Figure 1.1). Altricial birds are usually born blind and without feathers. Compared to precocial organisms, altricial organisms have a longer period of development before they reach maturity. Precocial organisms, such as the geese shown below, can take care of themselves at birth and do not require help from their parents ( Figure 1.1). In order to reproduce as much as possible, altricial and precocial organisms must use very different strategies. (left) A hummingbird nest with young il- lustrates an altricial reproductive strategy, with a few small eggs, helpless young, and intensive parental care. (right) The Canada goose shows a precocial repro- ductive strategy. It lays a large number of large eggs, producing well-developed young. "
the placenta supplies the developing baby with oxygen.,(A) true (B) false,A,"The fetus could not grow and develop without oxygen and nutrients from the mother. Wastes from the fetus also must be removed in order for it to survive. The exchange of these substances between the mother and fetus occurs through the placenta. The placenta is a temporary organ that starts to form shortly after implantation. It forms from the trophoblast layer of cells in the blastocyst and from maternal cells in the uterus. The placenta continues to develop and grow to meet the needs of the growing fetus. A fully developed placenta, like the one in Figure 22.8, is made up of a large mass of blood vessels from both mother and fetus. The maternal and fetal vessels are close together but separated by tiny spaces. This allows the mothers and fetuss blood to exchange substances across their capillary walls without the blood actually mixing. The fetus is connected to the placenta through the umbilical cord. This is a long tube that contains two arteries and a vein. Blood from the fetus enters the placenta through the umbilical arteries. It exchanges gases and other substances with the mothers blood. Then it travels back to the fetus through the umbilical vein. Another structure that supports the fetus is the amniotic sac. This is a membrane that surrounds and protects the fetus. It contains amniotic fluid, which consists of water and dissolved substances. The fluid allows the fetus to move freely until it grows to fill most of the available space. The fluid also cushions the fetus and helps protect it from injury. "
a typical pregnancy lasts 38 weeks.,(A) true (B) false,A,"From the eighth week following fertilization until birth, the developing human being is called a fetus. Birth typically occurs at about 38 weeks after fertilization, so the fetal period generally lasts about 30 weeks. During this time, the organs complete their development. The fetus also grows rapidly in length and weight. Some of the specific changes that occur during the fetal stage are listed in Figure 22.7. By the 38th week, the fetus is fully developed and ready to be born. A 38-week fetus normally ranges from about 36 to 51 centimeters (1420 inches) in length and weighs between 2.7 and 4.6 kilograms (about 610 pounds). "
by when have all the major organs started to develop?,(A) by the 2nd week after fertilization (B) by the 4th week after fertilization (C) by the 8th week after fertilization (D) by the 12th week after fertilization,C,"During the embryo stage, the baby grows in size. 3rd week after fertilization: Cells of different types start to develop. Cells that will form muscles and skin, for example, start to develop at this time. 4th week after fertilization: Body organs begin to form. 8th week after fertilization: All the major organs have started to develop. Pictured below are some of the changes that take place during the 4th and 8th weeks ( Figure 1.1). Look closely at the two embryos in the figure. Do you think that the older embryo looks more human? Notice that it has arms and legs and lacks a tail. The face has also started to form, and it is much bigger. Embryonic Development (Weeks 48). Most organs develop in the embryo during weeks four through eight. (Note: the drawings of the embryos are not to scale.) "
the heart is one of the first organs to develop. when does the heart begin to beat?,(A) during week 1 (B) during week 2 (C) during week 4 (D) during week 6,C,"The heart is a muscular organ in the chest. It consists mainly of cardiac muscle tissue. It pumps blood by repeated, rhythmic contractions. This produces the familiar lub-dub sound of each heartbeat. For a good video introduction to the heart and how it works, watch this entertaining Bill Nye video:  MEDIA Click image to the left or use the URL below. URL: "
"to have the best chance of survival, a premature baby should be delivered no earlier than week",(A) 26 (B) 28 (C) 30 (D) 32,B,"There are also many changes that take place after the embryo becomes a fetus. Some of the differences between them are obvious. For example, the fetus has ears and eyelids. Its fingers and toes are also fully formed. The fetus even has fingernails and toenails. In addition, the reproductive organs have developed to make the baby a male or female. The brain and lungs are also developing quickly. The fetus has started to move around inside the uterus. This is usually when the mother first feels the fetus moving. By the 28th week, the fetus is starting to look much more like a baby. Eyelashes and eyebrows are present. Hair has started to grow on the head. The body of the fetus is also starting to fill out as muscles and bones develop. Babies born after the 28th week are usually able to survive. However, they need help breathing because their lungs are not yet fully mature. A baby should not be delivered prior to this time, unless absolutely necessary. A baby born prior to week 28 will need considerable medical intervention to survive. During the last several weeks of the fetal period, all of the organs become mature. The most obvious change, however, is an increase in body size. The fetus rapidly puts on body fat and gains weight during the last couple of months. By the end of the 38th week, all of the organs are working, and the fetus is ready to be born. This is when birth normally occurs. A baby born before this time is considered premature. "
"in addition to the baby, what else forms inside the mothers uterus?",(A) the amniotic sac (B) placenta (C) and umbilical cord also form inside the uterus (D) b the placenta (E) c the umbilical cord (F) d all of the above,D,"During pregnancy, other structures also develop inside the mothers uterus. They are the amniotic sac, placenta, and umbilical cord ( Figure 1.2). Surrounding the fetus is the fluid-filled amniotic sac. The placenta and umbilical cord are also shown here. They provide a connection between the mothers and fetuss blood for the transfer of nutrients and gases. The amniotic sac is a membrane that surrounds the fetus. It is filled with water and dissolved substances, known as amniotic fluid. Imagine placing a small plastic toy inside a balloon and then filling the balloon with water. The toy would be cushioned and protected by the water. It would also be able to move freely inside the balloon. The amniotic sac and its fluid are like a water-filled balloon. They cushion and protect the fetus. They also let the fetus move freely inside the uterus. The placenta is a spongy mass of blood vessels. Some of the vessels come from the mother. Some come from the fetus. The placenta is attached to the inside of the mothers uterus. The fetus is connected to the placenta by a tube called the umbilical cord. The cord contains two arteries and a vein. Substances pass back and forth between the mothers and fetuss blood through the placenta and cord. Oxygen and nutrients pass from the mother to the fetus. Carbon dioxide passes from the fetus to the mother. It is important for the mother to eat plenty of nutritious foods during pregnancy. She must take in enough nutrients for the fetus as well as for herself. She needs extra calories, proteins, and lipids. She also needs more vitamins and minerals. In addition to eating well, the mother must avoid substances that could harm the embryo or fetus. These include alcohol, illegal drugs, and some medicines. It is especially important for her to avoid these substances during the first eight weeks after fertilization. This is when all the major organs are forming. Exposure to harmful substances during this time could damage the developing body systems. "
it is important for the mother to eat plenty of nutritious foods during pregnancy. it is also important for the mother to avoid,(A) alcohol (B) illegal drugs (C) and some medicines (D) b alcohol (E) soda and candy (F) c alcohol (G) airplane rides and amusement parks (H) d alcohol (I) illegal drugs and sexual relations,A,"The pregnant mother plays a critical role in the development of the embryo and fetus. She must avoid toxic substances such as alcohol, which can damage the developing offspring. She also must provide all the nutrients and other substances needed for normal growth and development. Most nutrients are needed in greater amounts by a pregnant woman because she is literally eating for two people. Thats why its important for a woman to eat plenty of nutritious foods during pregnancy. The pregnant woman in Figure 22.9 is eating a variety of fresh fruits, which provide energy, vitamins, and other nutrients. "
theoretically the supply of fresh water could run out.,(A) true (B) false,A,"It might seem like there is plenty of water on Earth, but thats not really the case. Water is a limited resource. That means that it is used faster than it is replaced. Theoretically, at some point in time, the supply of fresh water could run out. Though this is unlikely, it is possible. But it is a significant issue in parts of the world with large populations. As these populations continue to grow, the supply of water becomes an increasingly important issue. Even though we have lots of water in our oceans, we cannot use that water whenever we want. It takes special equipment, such as a desalination plant, and a lot of energy (and money) to convert salt water into fresh water. Of all the water on Earth, only about 1% can be used for drinking water. Almost all of the rest of the water is either salt water in the ocean or ice in glaciers and ice caps. As a result, there are water shortages many places in the world. Since we have such a limited supply of water, it is important to preserve our water supplies. Therefore, steps have been taken to prevent water pollution. Technologies have also been developed to conserve water and prevent water pollution. Sub-Saharan African countries have the most vulnerable water supplies. Some scientists believe of a potential future crisis in both Asia and Africa from pollution and depletion of natural water resources. Many countries in the Middle East are at an extreme risk of water shortages. Diminished water supplies could increase the risk of both internal conflicts or wars between countries. "
there are drinkable water shortages in many places of the planet.,(A) true (B) false,A,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
recycling wastewater is tremendously helpful. which of the following produces wastewater?,(A) water that has been used in washing clothes (B) water that has been used in flushing the toilet (C) water that has been used in showering (D) all of the above,D,"Fresh water is also preserved by purifying wastewater. Wastewater is water that has been used for cleaning, washing, flushing, or manufacturing. It includes the water that goes down your shower drain and that is flushed down your toilet. Instead of dumping wastewater directly into rivers, wastewater can be purified at a water treatment plant ( Figure 1.2). When wastewater is recycled, waterborne diseases caused by pathogens in sewage can be prevented. What are some ways you can save water in your own house? "
most of earths water,(A) is not drinkable (B) is in the oceans and ice caps (C) is saltwater (D) all of the above,D,"Most of Earths water is stored in the oceans, where it can remain for hundreds or thousands of years. "
the clean water act,(A) prevents the illegal dumping of contaminants into the water supply (B) prevents the illegal use of clean water (C) sets guidelines for water recycling (D) all of the above,A,"In the U.S., concern over water pollution has resulted in many federal laws. Some of these laws go all the way back to the 1800s! The laws prohibit the disposal of any waste into the nations rivers, lakes, streams, and other bodies of water, unless a person first has a permit. Growing concern for controlling water pollutants led to the enactment of the Clean Water Act in 1972. The Clean Water Act set water quality standards. It also limits the pollution that can enter the waterways. Other countries are also actively preventing water pollution and purifying water ( Figure 1.1). A water purification station in France. Contaminants are removed to make clean water. "
what is an advantage of recycling wastewater?,(A) Recycling wastewater produces fresh water (B) Recycling wastewater can help prevent waterborne diseases (C) Recycling wastewater increases the amount of water on Earth (D) all of the above,B,"Fresh water is also preserved by purifying wastewater. Wastewater is water that has been used for cleaning, washing, flushing, or manufacturing. It includes the water that goes down your shower drain and that is flushed down your toilet. Instead of dumping wastewater directly into rivers, wastewater can be purified at a water treatment plant ( Figure 1.2). When wastewater is recycled, waterborne diseases caused by pathogens in sewage can be prevented. What are some ways you can save water in your own house? "
"of all the water on earth, only about _____ % can be used for drinking water.",(A) 01 (B) 1 (C) 2 (D) 10,B,"One problem is that only a tiny fraction of Earths water is fresh, liquid water that people can use. More than 97 percent of Earths water is salt water in the oceans. Just 3 percent is freshwater. Most of the freshwater is frozen in ice sheets, icebergs, and glaciers (see Figure 21.5). "
the best way to avoid pathogens is to wash your hands often.,(A) true (B) false,A,"You can also take steps to avoid pathogens in the first place. The best way to avoid pathogens is to wash your hands often. You should wash your hands after using the bathroom or handling raw meat or fish. You should also wash your hands before eating or preparing food. In addition, you should also wash the food that your eat, and the utensils and countertop where food is prepared. In addition, you should wash your hands after being around sick people. The correct way to wash your hands is demonstrated below ( Figure 1.1). If soap and water arent available, use some hand sanitizer. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. Recall that a vector is an organism that carries pathogens from one person or animal to another. For example, ticks and mosquitoes are vectors, so you should wear long sleeves and long pants when appropriate to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. Many infectious diseases can be prevented with vaccinations. Immunization can drastically reduce your chances of contracting many diseases. You will read more about vaccinations in another concept. Vaccinations can help prevent measles, mumps, chicken pox, and several other diseases. If you do develop an infectious disease, try to avoid infecting others. Stay home from school until you are well. Also, take steps to keep your germs to yourself. Cover your mouth and nose with a tissue when you sneeze or cough, Watching the news will allow you to make informed decisions. If an outbreak of bad beef due to a bacterial infection is in the news, dont buy beef for a while. If tomatoes are making people sick, dont eat tomatoes until the outbreak is over. If a place has an unhealthy water supply, boil the water or drink bottled water. Local news can tell you of restaurants to avoid due to unhealthy conditions. And so on. "
keeping your immune system healthy helps to fight pathogens.,(A) true (B) false,A,"Eating healthy foods, getting enough sleep, and being active every day can help keep your respiratory system, cardiovascular system and immune system strong. Getting enough exercise makes your lungs stronger and better at giving your body the oxygen it needs. It also helps to boost your body fight germs that could make you sick. These can also, of course, keep your skeletal and muscular systems strong. "
"when washing your hands, how long should you scrub with soap?",(A) at least 10 seconds (B) at least 20 seconds (C) at least 30 seconds (D) at least 1 minute,B,"Washing your hands often, especially after sneezing, coughing, or blowing your nose, helps to protect you and others from diseases. Washing your hands for 20 seconds with soap and warm water can help prevent colds and flu. In one respect, you can think of hand washing as a survival skill. Some viruses and bacteria can live from 20 minutes to two hours or more on surfaces like cafeteria tables, doorknobs, and desks. Washing your hands often can remove many of these pathogens. Never touch your mouth, nose, or eyes without washing your hands. "
name three personal items that should not be shared.,(A) hairbrush (B) comb and soap (C) b toothbrush (D) comb and razor (E) c toothbrush (F) comb and soap (G) d hairbrush (H) comb and pencil,B,"Do not go to school or to other public places when you are sick. You risk spreading your illness to other people. You may also get even sicker if you catch something else. Do not share food and other things that go in the mouth, as in guzzling milk from the carton or double dipping chips. You never know what pathogens can be lurking around. Cover your mouth with a tissue when you cough or sneeze and to dispose of the tissue yourself. No time to grab a tissue. Cough or sneeze into the inside of your elbow instead of your hands. "
what do you think it means to use safe cooking practices?,(A) wash all fruits and vegetables well prior to eating (B) use separate clean cutting boards for raw meats and vegetables (C) keep clean countertops (D) all of the above,D,"Bacterial contamination of foods can lead to digestive problems, an illness known as food poisoning. Raw eggs and undercooked meats commonly carry the bacteria that can cause food poisoning. Food poisoning can be prevented by cooking meat thoroughly, which kills most microbes, and washing surfaces that have been in contact with raw meat. Washing your hands before and after handling food also helps prevent contamination. "
why is staying informed of current events important?,(A) to know if your water needs to be boiled (B) to know what restaurants to currently avoid (C) to know what foods may be currently contaminated (D) all of the above,D,"The last step of most scientific investigations is reporting the results. When scientists communicate their findings, they add to the body of scientific knowledge, and thats how science advances. Science generally builds on previous knowledge, sometimes advancing in giant steps but more often in baby steps. The brick building analogy in the Figure 1.1 may help you better understand why communication is important in science. When scientists communicate about their research, they may also get useful feedback from other scientists. For example, comments from other scientists might help them improve their research design or interpret their findings in a different way. Other scientists can also repeat the research to see if they get the same results. Q: Why might it be important for other scientists to repeat an investigation? A: If an investigation is repeated and different results are obtained, then it throws doubt on the original research. On the other hand, if the same results are obtained, scientists can place more confidence in them. "
"if you have an infectious disease, you should",(A) get vaccinated (B) stay home from school (C) drink plenty of fluids (D) all of the above,B,"What can you do to avoid infectious diseases? Eating well and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. Vaccines are available for some infectious diseases. For example, there are vaccines to prevent measles, mumps, whooping cough, and chicken pox. These vaccines are recommended for infants and young children. You can also take the following steps to avoid picking up pathogens or spreading them to others. Watch this video for additional information on preventing the spread of infectious diseases:  MEDIA Click image to the left or use the URL below. URL:  Wash your hands often with soap and water. Spend at least 20 seconds scrubbing with soap. See Figure 21.3 for effective hand washing tips. Avoid touching your eyes, nose, or mouth with unwashed hands. Avoid close contact with people who are sick. This includes kissing, hugging, shaking hands, and sharing cups or eating utensils. Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands. Disinfect frequently touched surfaces, such as keyboards and doorknobs, especially if someone is sick. Stay home when you are sick. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. For example, you can wear long sleeves and long pants to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. "
infectious diseases can't be passed from one person to another.,(A) true (B) false,B,"Infectious diseases are diseases that spread from person to person. They are caused by pathogens such as bacteria, viruses or fungi. What can you do to avoid infectious diseases? Eating right and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. The next best way is to avoid pathogens. Though this is difficult, there are steps you can take to limit your exposure to pathogens. Here are the ten best ways to prevent the spread of infectious diseases. 1. Wash your hands frequently. 2. Dont share personal items. 3. Cover your mouth when you cough or sneeze. 4. 5. 6. 7. 8. 9. 10. Get vaccinated. Use safe cooking practices. Be a smart traveler. Practice safe sex. Dont pick your nose (or your mouth or eyes either). Exercise caution with animals. Watch the news, and be aware of disease outbreaks. "
the use of tanning beds is a safe alternative to tanning in the sun.,(A) true (B) false,B,"Some sunlight is good for your health. Vitamin D is made in the skin when it is exposed to sunlight. But getting too much sun can be unhealthy. A sunburn is a burn to the skin that is caused by overexposure to UV radiation from the suns rays or tanning beds. Light-skinned people, like the man pictured below ( Figure 1.1), get sunburned more quickly than people with darker skin. This is because pigments (melanin) in the skin act as a natural sunblock that help to protect the body from UV radiation. With over one million new cases each year, skin cancer, which is cancer that forms in the tissues of the skin, is the most common form of human cancer. Children and teens who have been sunburned are at a greater risk of developing skin cancer later in life. Long-term exposure to UV radiation is the leading cause of skin cancer. About 90 percent of skin cancers are linked to sun exposure. UV radiation damages the genetic material (DNA) of skin cells. This damage can cause the skin cells to grow out of control and form a tumor. Some of these tumors are very difficult to cure. For this reason you should always wear sunscreen with a high sun protection factor (SPF), a hat, and clothing when out in the sun. Sunburn is caused by overexposure to UV rays. Getting sunburned as a child or a teen, especially sunburn that causes blistering, increases the risk of developing skin cancer later in life. "
what noninfectious diseases cause the most deaths in many developed countries?,(A) heart disease (B) stroke (C) diabetes and AIDS (D) b AIDS (E) stroke (F) diabetes and cancer (G) c heart disease (H) stroke (I) diabetes and cancer (J) d AIDS and smoking,C,"Noninfectious diseases cant be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If youre born with these conditions, you must learn how to manage the symptoms. Examples of conditions caused by environmental or lifestyle factors include heart disease and skin cancer. We cant change our genetic codes, but there are plenty of ways to prevent other noninfectious diseases. For example, cutting down on exposure to cigarette smoke and the suns rays will prevent certain types of cancer. It is a fact that most chronic noninfectious diseases can be prevented. The chronic noninfectious diseases that cause the most deaths in many developed countries are largely preventable. These diseases are heart disease, stroke, diabetes and cancer, and though they do have some genetic components, they also have many lifestyle components. For example, some cancers have genetic risks, but people at high risk for cancers can have screening examinations to catch them early or sometimes can take other steps to prevent the cancers. Heart disease, stroke and diabetes are mostly linked to lifestyle choices, even when family history puts a person at higher risk for the diseases. Most allergies can be prevented by avoiding the substances that cause them. For example, you can avoid pollens by staying indoors as much as possible. You can learn to recognize plants like poison ivy and not touch them. A good way to remember how to avoid poison ivy is ""leaves of three, let it be."" Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens, which are the substances that cause an allergic reaction. After many months or years of shots, the immune system gets used to the allergens and no longer responds to them. Type 1 diabetes and other autoimmune diseases cannot be prevented. But choosing a healthy lifestyle can help prevent type 2 diabetes. Getting plenty of exercise, avoiding high-fat foods, and staying at a healthy weight can reduce the risk of developing this type of diabetes. This is especially important for people who have family members with the disease. Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens, which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure 1.1). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesnt matter whether the radiation comes from tanning lamps or the sun. Overall, people in many developed countries are contributing to higher rates of noninfectious diseases (heart disease, stroke, diabetes and cancer) by taking advantage of technology and social environments that encourage a less active lifestyle, and also encourages faster and cheaper meals. For example, many children now spend more time on their computer or watching TV then playing outdoors. The ""faster and cheaper"" meals are usually less healthy than other meals. Even though many people are living longer, they can choose to live more healthily by adopting regular exercise routines and healthy eating habits. When you choose a sunscreen, select one with an SPF (sun protection factor) of 30 or higher. Also, choose a sunscreen that protects against both UVB and UVA radiation. "
what steps can a person take to help prevent type 2 diabetes?,(A) avoiding high-fat foods (B) staying at a healthy weight (C) getting plenty of exercise (D) all of the above,D,"Type 2 diabetes is much more common than type 1 diabetes. Type 2 diabetes occurs when body cells no longer respond normally to insulin. The pancreas still makes insulin, but the cells of the body cant use it. Being overweight and having high blood pressure increase the chances of developing type 2 diabetes. This type of diabetes usually develops in adulthood. However, it is becoming more common in teens and children because more young people are overweight now than ever before. You can greatly reduce your risk of developing type 2 diabetes by maintaining a healthy body weight. Some cases of type 2 diabetes can be cured with weight loss. However, most people with the disease need to take medicine to control their blood glucose. Regular exercise and balanced eating also help. Like people with type 1 diabetes, people with type 2 diabetes must frequently check their blood glucose. "
allergy shots,(A) are used to treat an allergic reaction (B) can help prevent autoimmune diseases (C) contain small amounts of allergens (D) all of the above,C,"An allergy is a disorder in which the immune system responds to a harmless substance as though it was a pathogen. Any substance that causes an allergy is called an allergen. The most common allergens are pollen, dust mites, mold, animal dander, insect stings, latex, and certain foods and medications. To see in greater detail how allergies occur, watch this animated video:  . MEDIA Click image to the left or use the URL below. URL:  Did you ever hear of hay fever? Its not really a fever, and it may have nothing to do with hay. Its actually an allergy to plant pollens. People with this type of allergy generally have seasonal allergies that come back year after year. Symptoms commonly include watery eyes and nasal congestion. Ragweed, shown blooming in Figure 21.8, causes more pollen allergies than any other plant. Allergy symptoms can range from mild to severe. Mild symptoms might include itchy eyes, sneezing, and a runny nose. Severe symptoms can cause difficulty breathing, which may be life threatening. Keep in mind that it is the immune system and not the allergen that causes the allergy symptoms. Allergy symptoms can be treated with medications such as antihistamines. Severe allergic reactions may require an injection of the hormone epinephrine. These treatments lessen or counter the immune systems response. Often, allergy symptoms can be prevented. One way is to avoid exposure to the allergens that cause your symptoms. If you are allergic to pollen, for example, you can reduce your exposure by staying inside when pollen levels are highest. Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens. After many months or years of shots, the immune system gets used to the allergens and no longer reacts to them. "
"to prevent skin cancer, a sunscreen should have a spf of at least",(A) 20 (B) 30 (C) 50 (D) 100,B,"Making healthy lifestyle choices can help prevent some types of cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen (see Figure 21.6). "
what is contributing to higher rates of noninfectious diseases in developed countries?,(A) better technology (B) faster and cheaper meals (C) less exercise (D) all of the above,D,"Noninfectious diseases cant be passed from one person to another. Instead, these types of diseases are caused by factors such as the environment, genetics, and lifestyle. Examples of inherited noninfectious conditions include cystic fibrosis and Down syndrome. If youre born with these conditions, you must learn how to manage the symptoms. Examples of conditions caused by environmental or lifestyle factors include heart disease and skin cancer. We cant change our genetic codes, but there are plenty of ways to prevent other noninfectious diseases. For example, cutting down on exposure to cigarette smoke and the suns rays will prevent certain types of cancer. It is a fact that most chronic noninfectious diseases can be prevented. The chronic noninfectious diseases that cause the most deaths in many developed countries are largely preventable. These diseases are heart disease, stroke, diabetes and cancer, and though they do have some genetic components, they also have many lifestyle components. For example, some cancers have genetic risks, but people at high risk for cancers can have screening examinations to catch them early or sometimes can take other steps to prevent the cancers. Heart disease, stroke and diabetes are mostly linked to lifestyle choices, even when family history puts a person at higher risk for the diseases. Most allergies can be prevented by avoiding the substances that cause them. For example, you can avoid pollens by staying indoors as much as possible. You can learn to recognize plants like poison ivy and not touch them. A good way to remember how to avoid poison ivy is ""leaves of three, let it be."" Some people receive allergy shots to help prevent allergic reactions. The shots contain tiny amounts of allergens, which are the substances that cause an allergic reaction. After many months or years of shots, the immune system gets used to the allergens and no longer responds to them. Type 1 diabetes and other autoimmune diseases cannot be prevented. But choosing a healthy lifestyle can help prevent type 2 diabetes. Getting plenty of exercise, avoiding high-fat foods, and staying at a healthy weight can reduce the risk of developing this type of diabetes. This is especially important for people who have family members with the disease. Making these healthy lifestyle choices can also help prevent some types of cancer. In addition, you can lower the risk of cancer by avoiding carcinogens, which are substances that cause cancer. For example, you can reduce your risk of lung cancer by not smoking. You can reduce your risk of skin cancer by using sunscreen. How to choose a sunscreen that offers the most protection is explained below ( Figure 1.1). Some people think that tanning beds are a safe way to get a tan. This is a myth. Tanning beds expose the skin to UV radiation. Any exposure to UV radiation increases the risk of skin cancer. It doesnt matter whether the radiation comes from tanning lamps or the sun. Overall, people in many developed countries are contributing to higher rates of noninfectious diseases (heart disease, stroke, diabetes and cancer) by taking advantage of technology and social environments that encourage a less active lifestyle, and also encourages faster and cheaper meals. For example, many children now spend more time on their computer or watching TV then playing outdoors. The ""faster and cheaper"" meals are usually less healthy than other meals. Even though many people are living longer, they can choose to live more healthily by adopting regular exercise routines and healthy eating habits. When you choose a sunscreen, select one with an SPF (sun protection factor) of 30 or higher. Also, choose a sunscreen that protects against both UVB and UVA radiation. "
cellular respiration occurs in the chloroplast.,(A) true (B) false,B,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
cellular respiration only occurs in the absence of oxygen.,(A) true (B) false,B,"Cellular Respiration is the process in which the cells of living things break down the organic compound glucose with oxygen to produce carbon dioxide and water. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2  6CO2 + 6H2 O As the Figure 1.1 shows, cellular respiration occurs in the cells of all kinds of organisms, including those that make their own food (autotrophs) as well as those that get their food by consuming other organisms (heterotrophs). Q: How is cellular respiration related to breathing? A: Breathing consists of inhaling and exhaling, and its purpose is to move gases into and out of the body. Oxygen needed for cellular respiration is brought into the body with each inhalation. Carbon dioxide and water vapor produced by cellular respiration are released from the body with each exhalation. "
when is most of the atp generated?,(A) during glycolysis (B) during the Krebs cycle (C) during the electron transport chain (D) during photosynthesis,C,"Stage three of cellular respiration is the use of NADH and FADH2 to generate ATP. This occurs in two parts. First, the NADH and FADH2 enter an electron transport chain, where their energy is used to pump, by active transport, protons (H+ ) into the intermembrane space of mitochondria. This establishes a proton gradient across the inner membrane. These protons then flow down their concentration gradient, moving back into the matrix by facilitated diffusion. During this process, ATP is made by adding inorganic phosphate to ADP. Most of the ATP produced during cellular respiration is made during this stage. For each glucose that starts cellular respiration, in the presence of oxygen (aerobic conditions), 36-38 ATP are generated. Without oxygen, under anaerobic conditions, much less (only two!) ATP are produced. "
how many atp are generated during glycolysis?,(A) 0 (B) 1 (C) 2 (D) 4,C,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
when are most of the nadh and fadh2 generated?,(A) during glycolysis (B) during the Krebs cycle (C) during the electron transport chain (D) during cellular respiration,B,"Stage three of cellular respiration is the use of NADH and FADH2 to generate ATP. This occurs in two parts. First, the NADH and FADH2 enter an electron transport chain, where their energy is used to pump, by active transport, protons (H+ ) into the intermembrane space of mitochondria. This establishes a proton gradient across the inner membrane. These protons then flow down their concentration gradient, moving back into the matrix by facilitated diffusion. During this process, ATP is made by adding inorganic phosphate to ADP. Most of the ATP produced during cellular respiration is made during this stage. For each glucose that starts cellular respiration, in the presence of oxygen (aerobic conditions), 36-38 ATP are generated. Without oxygen, under anaerobic conditions, much less (only two!) ATP are produced. "
what occurs during stage 3 of cellular respiration?,(A) NADH and FADH2 are used to generate ATP (B) pyruvate is produced (C) The energy in pyruvate is converted into NADH and FADH2 (D) sunlight is absorbed,A,"Stage one of cellular respiration is glycolysis. Glycolysis is the splitting, or lysis of glucose. Glycolysis converts the 6-carbon glucose into two 3-carbon pyruvate molecules. This process occurs in the cytoplasm of the cell, and it occurs in the presence or absence of oxygen. During glycolysis a small amount of NADH is made as are four ATP. Two ATP are used during this process, leaving a net gain of two ATP from glycolysis. The NADH temporarily holds energy, which will be used in stage three. "
how is atp made during the electron transport chain?,(A) by active transport (B) by facilitated diffusion (C) by anaerobic processes (D) by the Krebs cycle,B,"Stage three of cellular respiration is the use of NADH and FADH2 to generate ATP. This occurs in two parts. First, the NADH and FADH2 enter an electron transport chain, where their energy is used to pump, by active transport, protons (H+ ) into the intermembrane space of mitochondria. This establishes a proton gradient across the inner membrane. These protons then flow down their concentration gradient, moving back into the matrix by facilitated diffusion. During this process, ATP is made by adding inorganic phosphate to ADP. Most of the ATP produced during cellular respiration is made during this stage. For each glucose that starts cellular respiration, in the presence of oxygen (aerobic conditions), 36-38 ATP are generated. Without oxygen, under anaerobic conditions, much less (only two!) ATP are produced. "
every cell in your body needs atp to make oxygen.,(A) true (B) false,B,"What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be converted to a net total of 36 or 38 molecules of ATP. This only occurs in the presence of oxygen. "
the lungs pump oxygen to every cell in your body.,(A) true (B) false,B,"After the blood in the capillaries in the lungs picks up oxygen, it leaves the lungs and travels to the heart. The heart pumps the oxygen-rich blood into arteries, which carry it throughout the body. The blood passes eventually into capillaries that supply body cells. "
what artery receives blood directly from the heart?,(A) the aorta (B) the coronary artery (C) the pulmonary artery (D) the main artery,A,"The blood vessels are an important part of the cardiovascular system. They connect the heart to every cell in the body. Arteries carry blood away from the heart, while veins return blood to the heart ( Figure 1.1). The right side of the heart pumps de- oxygenated blood into pulmonary circula- tion, while the left side pumps oxygenated blood into systemic circulation. "
which best characterizes the blood that returns to the heart from the lungs?,(A) blood-rich (B) blood-poor (C) oxygen-rich (D) oxygen-poor,C,"Pulmonary circulation is the part of the cardiovascular system that carries oxygen-poor blood away from the heart and brings it to the lungs. Oxygen-poor blood returns to the heart from the body and leaves the right ventricle through the pulmonary arteries, which carry the blood to each lung. Once at the lungs, the red blood cells release carbon dioxide and pick up oxygen when you breathe. The oxygen-rich blood then leaves the lungs through the pulmonary veins, which return it to the left side of the heart. This completes the pulmonary cycle. The oxygenated blood is then pumped to the body through systemic circulation, before returning again to pulmonary circulation. "
through what type of blood vessel does oxygen move from the blood into the cells?,(A) the aorta (B) the arteries (C) the veins (D) the capillaries,D,"Breathing is only part of the process of bringing oxygen to where it is needed in the body. After oxygen enters the lungs, what happens? 1. The oxygen enters the bloodstream from the alveoli, tiny sacs in the lungs where gas exchange takes place ( Figure 1.1). The transfer of oxygen into the blood is through simple diffusion. 2. The oxygen-rich blood returns to the heart. 3. Oxygen-rich blood is then pumped through the aorta, the large artery that receives blood directly from the heart. 4. From the aorta, oxygen-rich blood travels to the smaller arteries and, finally, to the capillaries, the smallest type of blood vessel. 5. The oxygen molecules move, by diffusion, out of the capillaries and into the body cells. 6. While oxygen moves from the capillaries and into body cells, carbon dioxide moves from the cells into the capillaries. Gas exchange is the movement of oxygen into the blood and carbon dioxide out of the blood. 7. Carbon dioxide is brought, through the blood, back to the heart and then to the lungs. Then it is released into the air during exhalation. Why is oxygen needed by each cell in your body? To make ATP, the usable form of cellular energy. Oxygen is needed in the final stage of cellular respiration, which is the process of converting glucose into ATP. This process is much more efficient in the presence of oxygen. Without oxygen, much less ATP is produced. As ATP is needed for the cells to function properly, every cell in your body needs oxygen. Getting that oxygen begins with inhaling. The oxygen moves into your blood, where it travels to every cell in your body. "
where does gas exchange occur in the lungs?,(A) the alveoli (B) the aorta (C) the capillaries (D) all of the above,A,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
what gas moves in the blood back to the lungs to be exhaled?,(A) carbon gas (B) oxygen (C) carbon dioxide (D) nitrogen gas,C,"Most of the time, you breathe without thinking about it. Breathing is mostly an involuntary action that is controlled by a part of your brain that also controls your heart beat. If you swim, do yoga, or sing, you know you can control your breathing, however. Taking air into the body through the nose and mouth is called inhalation. Pushing air out of the body through the nose or mouth is called exhalation. The woman pictured below is exhaling before she surfaces from the pool water (Figure 1.1). How do lungs allow air in? Air moves into and out of the lungs by the movement of muscles. The most important muscle in the process of breathing is the diaphragm, a sheet of muscle that spreads across the bottom of the rib cage. The diaphragm and rib muscles contract and relax to move air into and out of the lungs. During inhalation, the diaphragm contracts and moves downward. The rib muscles contract and cause the ribs to move outward. This causes the chest volume to increase. Because the chest volume is larger, the air pressure inside the lungs is lower than the air pressure outside. This difference in air pressures causes air to be sucked into the lungs. When the diaphragm and rib muscles relax, air is pushed out of the lungs. Exhalation is similar to letting the air out of a balloon. How does the inhaled oxygen get into the bloodstream? The exchange of gasses between the lungs and the blood happens in tiny sacs called alveoli. The walls of the alveoli are very thin and allow gases to pass though them. The alveoli are lined with capillaries (Figure 1.2). Oxygen moves from the alveoli to the blood in the capillaries that surround the alveoli. At the same time, carbon dioxide moves in the opposite direction, from capillary blood to the alveoli. The gases move by simple diffusion, passing from an area of high concentration to an area of low concentration. For example, initially there is more oxygen in the alveoli than in the blood, so oxygen moves by diffusion from the alveoli into the blood. "
most producers make glucose through photosynthesis.,(A) true (B) false,A,"Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs (""self feeders""). All other living things obtain glucose by eating autotrophs (or organisms that eat autotrophs). These living things are called heterotrophs (""other feeders""). "
energy is recycled through an ecosystem.,(A) true (B) false,B,"Ecosystems need a constant input of energy to supply the needs of their organisms. Most ecosystems get energy from sunlight. A few ecosystems get energy from chemical compounds. Unlike energy, matter doesnt need to be constantly added to ecosystems. Instead, matter is recycled through ecosystems. Water and elements such as carbon and nitrogen that living things need are used over and over again. "
what is the chemical formula of glucose?,(A) C8H12O8 (B) C6H6O6 (C) C6H12O6 (D) C12H6O12,C,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
what are the necessary ingredients for photosynthesis?,(A) sunlight (B) carbon dioxide and oxygen (C) b sunlight (D) carbon dioxide and water (E) c sunlight (F) oxygen and water (G) d sunlight only,B,"What goes into the plant cell to start photosynthesis? The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the suns energy are necessary for photosynthesis to occur. These three components must meet in the chloroplast of the leaf cell for photosynthesis to occur. How do these three components get to the cells in the leaf? Chlorophyll is the green pigment in leaves that captures energy from the sun. Chlorophyll molecules are located in the thylakoid membranes inside chloroplasts. The veins in a plant carry water from the roots to the leaves. Carbon dioxide enters the leaf from the air through special openings called stomata ( Figure 1.2). "
what are the most common producers in the ocean?,(A) phytoplankton (B) seaweed (C) marine plants (D) bacteria,A,"When you think of life in the ocean, do you think of fish? Actually, fish are not the most common life forms in the ocean. Plankton are the most common. Plankton make up one of three major groups of marine life. The other two groups are nekton and benthos. Figure 14.24 shows the three groups. "
how is food produced in ecosystems without sunlight?,(A) by photosynthesis (B) by phytoplankton (C) by chemosynthesis (D) by autosynthesis,C,"Most ecosystems get their energy from the Sun. Only producers can use sunlight to make usable energy. Producers convert the sunlight into chemical energy or food. Consumers get some of that energy when they eat producers. They also pass some of the energy on to other consumers when they are eaten. In this way, energy flows from one living thing to another. "
"essentially, almost all energy on earth originates from",(A) plants (B) the sun (C) photosynthesis (D) food,B,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
puberty normally starts earlier in boys.,(A) true (B) false,B,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
adolescence normally begins around age 14.,(A) true (B) false,B,"Adolescence is the stage of life between the start of puberty and the beginning of adulthood. Adolescence begins with the physical changes of puberty. It also includes many other changes, including mental, emotional, and social changes. During adolescence: Teens develop new thinking abilities. For example, they develop the ability to understand abstract ideas, such as honesty and freedom. Their ability to think logically also improves. They usually get better at problem solving as well. Teens try to establish a sense of identity. They typically become increasingly independent from their parents. Many teens have emotional ups and downs. This is at least partly due to their changing hormone levels. Teens usually start spending more time with their peers, like the girls in Figure 22.13. Adolescents usually spend much more time with their friends and classmates than they do with family members. "
during adolescence many teenagers develop new thinking abilities. these include,(A) the ability to think logically (B) developing abstract ideas (C) the ability to solve problems (D) all of the above,D,"Adolescence is the period of life between the start of puberty and the beginning of adulthood. Adolescence includes the physical changes of puberty. It also includes many other changes, including significant mental, emotional, and social changes. During adolescence: Teenagers develop new thinking abilities. For example, they can think about abstract ideas, such as freedom. They are also better at thinking logically. They are usually better at solving problems as well. Teenagers try to establish a sense of who they are as individuals. They may try to become more independent from their parents. Most teens also have emotional ups and downs. This is partly due to changing hormone levels. Teenagers usually spend much more time with peers than with family members. "
"during adolescence, significant _______________ changes occur.",(A) physical (B) mental (C) chemical (D) and biological (E) b physical (F) mental (G) emotional (H) and social (I) c physical (J) chemical (K) emotional (L) and social (M) d physical (N) mental (O) chemical (P) and creative,B,"Adolescence is the stage of life between the start of puberty and the beginning of adulthood. Adolescence begins with the physical changes of puberty. It also includes many other changes, including mental, emotional, and social changes. During adolescence: Teens develop new thinking abilities. For example, they develop the ability to understand abstract ideas, such as honesty and freedom. Their ability to think logically also improves. They usually get better at problem solving as well. Teens try to establish a sense of identity. They typically become increasingly independent from their parents. Many teens have emotional ups and downs. This is at least partly due to their changing hormone levels. Teens usually start spending more time with their peers, like the girls in Figure 22.13. Adolescents usually spend much more time with their friends and classmates than they do with family members. "
"in girls, puberty begins with the secretion of",(A) the menstrual period (B) testosterone (C) estrogen (D) eggs,C,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
which of the following occur during puberty?,(A) The shoulders broaden (B) and the voice becomes deeper (C) b The testes start making semen (D) c Public hair grows (E) d all of the above,A,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
which of the following occur during puberty?,(A) The menstrual cycle begins (B) The hips widen (C) and the breasts develop (D) c The ovaries start releasing eggs (E) d all of the above,D,"Puberty is the stage of life when a child becomes sexually mature. Puberty lasts from about 12 to 18 years of age in boys and from about 10 to 16 years of age in girls. The age when puberty begins is different from one child to another. Children that begin puberty much earlier or later than their peers may feel self-conscious. They may also worry that something is wrong with them. Usually, an early or late puberty is perfectly normal. In boys, puberty begins when the pituitary gland tells the testes to secrete testosterone. Testosterone causes the following to happen: 1. 2. 3. 4. The penis and testes grow. The testes start making sperm. Pubic and facial hair grow. The shoulders broaden, and the voice becomes deeper. In girls, puberty begins when the pituitary gland tells the ovaries to secrete estrogen. Estrogen causes the following to happen: 1. 2. 3. 4. 5. The uterus and ovaries grow. The ovaries start releasing eggs. The menstrual cycle begins. Pubic hair grows. The hips widen, and the breasts develop. Boys and girls are close to the same height during childhood. In both boys and girls, growth in height and weight is very fast during puberty. But boys grow faster than girls during puberty. Their period of fast growth also lasts longer. By the end of puberty, boys are an average of 10 centimeters (4 inches) taller than girls. "
a clone can be a fairly close genetic copy.,(A) true (B) false,B,"Cloning is the process of creating an exact genetic replica of an organism. The clones DNA is exactly the same as the parents DNA. Bacteria and other single-celled organisms have long been able to clone themselves through asexual reproduction. Plants can also reproduce asexually. In animals, however, cloning does not happen naturally. In 1997, that all changed when a sheep named Dolly was the first large mammal ever to be successfully cloned. Other animals can now also be cloned in a laboratory. The process of producing an animal like Dolly starts with a single cell from the animal that is going to be cloned. Below are the steps involved in the process of cloning: 1. In the case of Dolly, cells from the mammary glands were taken from the adult that was to be cloned. But other somatic cells can be used. Somatic cells come from the body and are not gametes like sperm or egg. 2. The nucleus is removed from this cell. 3. The nucleus is placed in a donor egg that has had its nucleus removed. The nucleus must be removed from the donor egg to maintain the appropriate chromosome number. 4. The new cell is stimulated with an electric shock and embryo development begins, as if it were a normal zygote. The zygote is the first cell of a new organism. 5. The resulting embryo is implanted into a mother sheep, where it continue its development ( Figure 1.1). To clone an animal, a nucleus from the animals cells are fused with an egg cell (from which the nucleus has been re- moved) from a donor, creating a new zy- gote. "
a plasmid is a chromosome from a bacterium.,(A) true (B) false,B,"Bacteria have small rings of DNA in the cytoplasm, called plasmids ( Figure 1.1). A plasmid is not part of the bacterial chromosome, but an additional pieced of DNA. When putting foreign DNA into a bacterium, the plasmids are often used as a vector. Viruses can also be used as vectors. The manipulation of the plasmid DNA, and then the insertion of the recombinant plasmid into a bacterium, is an invaluable tool in scientific research. This image shows a drawing of a plasmid. The plasmid has two large segments and one small segment depicted. The two large segments (green and blue) indicate antibiotic resistances usually used in a screening procedure. The antibiotic resis- tance segments ensure only bacteria with the plasmid will grow. The small segment (red) indicates an origin of replication. The origin of replication is where DNA replication starts, copying the plasmid. "
what is the first step in gene cloning?,(A) Placing a plasmid into a host cell (B) Placing the gene of interest into a host cell (C) Placing the gene of interest into a vector (D) Placing a plasmid into a vector,C,"Biotechnology uses a variety of methods, but some are commonly used in many applications. A common method is the polymerase chain reaction. Another common method is gene cloning. The polymerase chain reaction is a way of making copies of a gene. It uses high temperatures and an enzyme to make new DNA molecules. The process keeps cycling to make many copies of a gene. Gene cloning is another way of making copies of a gene. A gene is inserted into the DNA of a bacterial cell. Figure 6.15 shows how this is done. Bacteria multiply very rapidly by binary fission. Each time a bacterial cell divides, the inserted gene is copied. "
which of the following statements is true?,(A) Cloned genes are used in medicine and agriculture (B) Bacteria can easily produce human proteins (C) A vector is replicated inside a bacterial cell (D) All of the above statements are true,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
what is the origin of replication?,(A) A spot in the DNA sequence of a plasmid that signals the beginning of (B) A spot in the DNA sequence of a gene that signals the beginning of replication (C) A spot in the DNA sequence of a cell that signals the beginning of replication (D) A spot in the DNA sequence of a plasmid that signals the beginning of transcription,A,"Many scientists think that RNA was the first replicator. Since RNA catalyzes protein synthesis, most scientists think that RNA came before proteins. RNA can also encode genetic instructions and carry it to daughter cells, such as DNA. The idea that RNA is the most primitive organic molecule is called the RNA world hypothesis, referring to the possibility that the RNA is more ancient than DNA. RNA can pass along genetic instructions as DNA can, and some RNA can carry out chemical reactions like proteins can. Click image to the left or use the URL below. URL:  Pieces of many scenarios can be put together to come up with a plausible suggestion for how life began. Click image to the left or use the URL below. URL: "
what is the purpose of antibiotic resistance segments?,(A) The antibiotic resistance segments ensure only bacteria with insulin will grow (B) The antibiotic resistance segments ensure only plasmids with the bacteria will grow (C) The antibiotic resistance segments ensure only bacteria with the plasmid will (D) The antibiotic resistance segments ensure only plasmids with the insulin will grow,C,"Bacteria have small rings of DNA in the cytoplasm, called plasmids ( Figure 1.1). A plasmid is not part of the bacterial chromosome, but an additional pieced of DNA. When putting foreign DNA into a bacterium, the plasmids are often used as a vector. Viruses can also be used as vectors. The manipulation of the plasmid DNA, and then the insertion of the recombinant plasmid into a bacterium, is an invaluable tool in scientific research. This image shows a drawing of a plasmid. The plasmid has two large segments and one small segment depicted. The two large segments (green and blue) indicate antibiotic resistances usually used in a screening procedure. The antibiotic resis- tance segments ensure only bacteria with the plasmid will grow. The small segment (red) indicates an origin of replication. The origin of replication is where DNA replication starts, copying the plasmid. "
which best describes a plasmid?,(A) A large ring of DNA in the cytoplasm of a bacterium (B) A small round piece of bacterial DNA (C) A small ring of DNA in the cytoplasm of many organisms (D) A large extrachromosomal piece of prokaryotic DNA,B,"Bacteria have small rings of DNA in the cytoplasm, called plasmids ( Figure 1.1). A plasmid is not part of the bacterial chromosome, but an additional pieced of DNA. When putting foreign DNA into a bacterium, the plasmids are often used as a vector. Viruses can also be used as vectors. The manipulation of the plasmid DNA, and then the insertion of the recombinant plasmid into a bacterium, is an invaluable tool in scientific research. This image shows a drawing of a plasmid. The plasmid has two large segments and one small segment depicted. The two large segments (green and blue) indicate antibiotic resistances usually used in a screening procedure. The antibiotic resis- tance segments ensure only bacteria with the plasmid will grow. The small segment (red) indicates an origin of replication. The origin of replication is where DNA replication starts, copying the plasmid. "
the worlds population is growing so fast that resources are becoming limited.,(A) true (B) false,A,"Every 20 minutes, the human population adds 3,500 more people. More people need more resources. For example, we now use five times more fossil fuels than we did in 1970. The human population is expected to increase for at least 40 years. What will happen to resource use? "
reusing means processing used materials in order to make them suitable for other uses.,(A) true (B) false,B,"Reusing resources means using items again instead of throwing them away. A reused item can be used in the same way by someone else. Or it can be used in a new way. For example, Shana has a pair of jeans she has outgrown. She might give them to her younger sister to wear. Or she might use them to make something different for herself, say, a denim shoulder bag. Some other ideas for reusing resources are shown in Figure 20.7. "
items that should be recycled include,(A) clothing (B) tires and batteries (C) b electronics (D) iron and steel (E) c paper and glass (F) d all of the above,D,"If an item can no longer be used or reused, try to recycle it. Recycling means taking a used item, breaking it down, and reusing the components. It generally takes less energy to recycle materials than obtain new ones. Recycling also keeps waste out of landfills. Some of the items that can be recycled include: glass, paper, cardboard, plastic, aluminum, iron, steel, batteries, electronics, tires, and concrete. You can learn how some of these materials are recycled by watching this video:  . MEDIA Click image to the left or use the URL below. URL:  Even kitchen scraps and garden wastes can be recycled. They can be tossed into a compost bin, like the one in Figure 25.13. The recycled compost gradually breaks down to form rich humus that can be added to lawns and gardens to improve the soil. Encourage your family to recycle if they dont already. Even if you dont have curbside recycling where you live, there are likely to be recycling drop boxes or centers available for recycling many items. If you have recycling bins at school, be sure to use them. If not, raise the issue with your teacher or principal. You can also write a letter to the editor of your local newspaper encouraging everyone in your community to recycle. "
how can water be reused?,(A) Rain can be caught in rain barrels and used to water your garden (B) Purified sewage water can be used for fountains (C) fire fighting (D) and irrigating crops (E) c Water that has been used for laundry can be used to water the garden (F) d all of the above,D,"Lets now look at what we can reuse. Reusing includes using the same item again for the same function and also using an item again for a new function. Reuse can have both economic and environmental benefits. New packaging regulations are helping society to move towards these goals. Water is a resource that can be reused for numerous purposes. You may not drink used water, but it is quite useful for other purposes. Some ways of reusing resources include: Use reusable bags when shopping. Use gray water. Water that has been used for laundry, for example, can be used to water the garden or flush toilets. At the town level, purified sewage water can be used for fountains, watering public parks or golf courses, fire fighting, and irrigating crops. Rain can be caught in rain barrels and used to water your garden. What are some other ways to reuse resources? "
what are ways to reduce?,(A) Turn the television off when no one is watching (B) Use low-flow shower heads (C) Use as little air conditioning as possible (D) all of the above,D,"What exactly does it mean to reduce? Reducing means decreasing the amount of waste we create. That could also mean cutting down on use of natural resources. In addition, many ways to reduce also result in saving money. Minimizing of waste may be difficult to achieve for individuals and households, but here are some starting points that you can include in your daily routine to reduce the use of resources: Turn lights off when not using them. Turn the television off when no one is watching. Replace burned out bulbs with ones that are more energy-efficient ( Figure 1.1). Reduce water use by turning off faucets when not using water. Use low-flow shower heads, which save on water and use less energy. Use low-flush and composting toilets. Put kitchen and garden waste into a compost pile. In the summer, change filters on your air conditioner and use as little air conditioning as possible. The use of air conditioning uses a lot of energy. In winter, make sure your furnace is working properly and make sure there is enough insulation on windows and doors. Mend broken or worn items instead of buying new ones. When you go shopping for items, buy quantities you know you will use without waste. Walk or bicycle instead of using an automobile, in order to save on fuel usage and costs, and to cut down on pollution. When buying a new vehicle, check into hybrid, semi-hybrid, or electric models to cut down on gas usage and air pollution. These fluorescent light bulbs are much more energy efficient than standard light bulbs. "
using grey water is an example of,(A) reducing (B) reusing (C) recycling (D) remaking,B,"Lets now look at what we can reuse. Reusing includes using the same item again for the same function and also using an item again for a new function. Reuse can have both economic and environmental benefits. New packaging regulations are helping society to move towards these goals. Water is a resource that can be reused for numerous purposes. You may not drink used water, but it is quite useful for other purposes. Some ways of reusing resources include: Use reusable bags when shopping. Use gray water. Water that has been used for laundry, for example, can be used to water the garden or flush toilets. At the town level, purified sewage water can be used for fountains, watering public parks or golf courses, fire fighting, and irrigating crops. Rain can be caught in rain barrels and used to water your garden. What are some other ways to reuse resources? "
putting garden waste into a compost pile is an example of,(A) reducing (B) reusing (C) recycling (D) redoing,A,"Biomass is the material that comes from plants and animals that were recently living. Biomass can be burned directly, such as setting fire to wood. For as long as humans have had fire, people have used biomass for heating and cooking. People can also process biomass to make fuel, called biofuel. Biofuel can be created from crops, such as corn or Biofuels, such as ethanol, are added to gasoline to cut down the amount of fossil fuels that are used. algae, and processed for use in a car (Figure 1.1). The advantage to biofuels is that they burn more cleanly than fossil fuels. As a result, they create less pollution and less carbon dioxide. Organic material, like almond shells, can be made into electricity. Biomass power is a great use of wastes and is more reliable than other renewable energy sources, but harvesting biomass energy uses energy and biomass plants produce pollutants including greenhouse gases. Cow manure can have a second life as a source of methane gas, which can be converted to electricity. Not only that food scraps can also be converted into green energy. Food that is tossed out produces methane, a potent greenhouse gas. But that methane from leftovers can be harnessed and used as fuel. Sounds like a win-win situation. "
the ocean tides are a renewable resource.,(A) true (B) false,A,"A resource is renewable if it is remade by natural processes at the same rate that humans use it up. Sunlight and wind are renewable resources because they will not be used up ( Figure 1.1). The rising and falling of ocean tides is another example of a resource in unlimited supply. A sustainable resource is a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs. People can sustainably harvest wood, cork, and bamboo. Farmers can also grow crops sustainably by not planting the same crop in their soil year after year. Planting the same crop each year can remove nutrients from the soil. This means that wood, cork, bamboo, and crops can be sustainable resources. "
fossil fuels are an example of nonrenewable resources.,(A) true (B) false,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
this form of alternative energy uses the natural flow of heat from the earths core to produce steam.,(A) solar power (B) geothermal power (C) wind power (D) hydropower,B,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
these three alternative energy sources are generated by turning turbines.,(A) wind power (B) solar power and hydropower (C) b wind power (D) solar power and geothermal power (E) c wind power (F) hydropower and geothermal power (G) d hydropower (H) solar power and geothermal power,C,"Switching to renewable energy sources solves many of the problems associated with nonrenewable energy. While it may be expensive to develop renewable energy sources, they are clearly the way of the future. Figure 25.11 represents three different renewable energy sources: solar, wind, and biomass energy. The three types are described below. You can watch Bill Nyes introduction to renewable energy resources in this video:  MEDIA Click image to the left or use the URL below. URL:  Solar energy is energy provided by sunlight. Solar cells can turn sunlight into electricity. The energy in sunlight is virtually limitless and free and creates no pollution to use. Wind energy is energy provided by the blowing wind. Wind turbines, like those in Figure 25.11, can turn wind energy into electricity. The wind blows because of differences in heating of Earths atmosphere by the sun. There will never be a shortage of wind. Biomass energy is energy provided by burning or decomposing organic matter. For example, when garbage decomposes in a landfill, it releases methane gas. This gas can be captured and burned to produce electricity. Crops such as corn can also be converted into a liquid fuel and added to gasoline. Although biomass is renewable, burning it produces carbon dioxide, similar to fossil fuels. "
sustainable resources include,(A) wood (B) bamboo and wind (C) b wood (D) cork and crops (E) c cork (F) crops and water (G) d sunlight and wind,B,"A resource is renewable if it is remade by natural processes at the same rate that humans use it up. Sunlight and wind are renewable resources because they will not be used up ( Figure 1.1). The rising and falling of ocean tides is another example of a resource in unlimited supply. A sustainable resource is a resource that is used in a way that meets the needs of the present without keeping future generations from meeting their needs. People can sustainably harvest wood, cork, and bamboo. Farmers can also grow crops sustainably by not planting the same crop in their soil year after year. Planting the same crop each year can remove nutrients from the soil. This means that wood, cork, bamboo, and crops can be sustainable resources. "
this form of alternative energy is used to generate electricity.,(A) hydropower (B) wind power (C) geothermal power (D) all of the above,D,"Electricity originates in power plants. They have electric generators that produce electricity by electromagnetic induction. In this process, a changing magnetic field is used to generate electric current. The generators convert kinetic energy to electrical energy. The kinetic energy may come from flowing water, burning fuel, wind, or some other energy source. "
why are alternative energy sources important?,(A) Because they are needed to take the place of fossil fuels (B) Because they use renewable resources (C) Because some produce no waste or pollution (D) all of the above,D,"Some of the resources we depend on the most are energy resources. Whether its powering our lights and computers, heating our homes, or providing energy for cars and other vehicles, its hard to imagine what our lives would be like without a constant supply of energy. "
girls should use feminine hygiene products on a regular basis.,(A) true (B) false,B,"As was discussed in previous concepts, both infectious and noninfectious diseases of the reproductive system can be very serious. But there are ways to keep your reproductive system healthy. What can you do to keep your reproductive system healthy? You can start by making the right choices for overall good health. To be as healthy as you can be, you should: Eat a balanced diet that is high in fiber and low in fat. Drink plenty of water. Get regular exercise. Maintain a healthy weight. Get enough sleep. Avoid using tobacco, alcohol, or other drugs. Manage stress in healthy ways. Keeping your genitals clean is also very important. A daily shower or bath is all that it takes. Females do not need to use special feminine hygiene products. In fact, using them may do more harm than good because they can irritate the vagina or other reproductive structures. You should also avoid other behaviors that can put you at risk. Do not get into contact with another persons blood or other body fluids. For example, never get a tattoo or piercing unless you are sure that the needles have not been used before. This is one of the most important ways to prevent an STI. Of course, the only way to be fully protected against STIs is to refrain from sexual activity. If you are a boy, you should always wear a protective cup when you play contact sports. Contact sports include football, boxing, and hockey. Wearing a cup will help protect the testes from injury. You should also do a monthly self-exam to check for cancer of the testes. If you are a girl and use tampons, be sure to change them every four to six hours. Leaving tampons in for too long can put you at risk of toxic shock syndrome. This is a serious condition. Signs and symptoms of toxic shock syndrome develop suddenly, and the disease can be fatal. The disease involves fever, shock, and problems with the function of several body organs. Girls should also get in the habit of doing a monthly self-exam to check for breast cancer. Although breast cancer is rare in teens, its a good idea to start doing the exam when you are young. It will help you get to know what is normal for you. "
a daily shower or bath protects the reproductive system.,(A) true (B) false,A,"Maintaining overall good health will help keep your reproductive system healthy. You should eat right, get regular exercise, and follow other healthy lifestyle behaviors. In addition, the following practices will help keep the reproductive system healthy: Keep the genitals clean. A daily shower or bath is all thats needed. Avoid harsh soaps or other personal hygiene products that may be irritating. Avoid risky behaviors. This includes contact with blood or dirty needles as well as sexual activity. If you are a girl and use tampons, be sure to change them every 4 to 6 hours. This will reduce your risk of toxic shock syndrome. This is a very dangerous condition that may occur if tampons are left in too long. If you are a boy, wear a protective cup if you play a contact sport. This will help protect the testes from injury. You should also learn how to check yourself for testicular cancer (see Figure 22.16). You can learn how by watching this video:  MEDIA Click image to the left or use the URL below. URL: "
"girls, do not use tampons for longer than",(A) 1 hour (B) 3 hours (C) 6 hours (D) 10 hours,C,"The menstrual cycle is a series of changes in the reproductive system of mature females that repeats every month. While the egg and follicle are developing in the ovary, tissues are building up inside the uterus, the reproductive organ where the baby would develop. The uterus develops a thick lining covered in tiny blood vessels. This prepares the uterus to receive an egg that could develop into a child (a fertilized egg). The occurs during the first part of the cycle. Ovulation, the release of an egg from the ovary, occurs at about the midpoint of the cycle. This would be around day 14 of a 28 day cycle. The egg is swept into the fallopian tube. If sperm is present, fertilization may occur. As sperm can only survive in the fallopian tube for up to a few days, fertilization can only occur within those few days post-ovulation. If the egg is fertilized, the egg makes its way through the fallopian tube into the uterus, where it imbeds into the thick lining. When this occurs, the monthly cycle stops. The monthly cycle does not resume until the pregnancy is over. If a sperm does not enter an egg, the lining of the uterus breaks down. Blood and other tissues from the lining break off from the uterus. They pass through the vagina and out of the body. This is called menstruation. Menstruation is also called a menstrual period. It lasts about 4 days, on average. When the menstrual period ends, the cycle repeats. Some women feel discomfort during this process. Some people think that the average length of a menstrual period is the same as the normal length. They assume that shorter or longer menstrual periods are not normal. In fact, menstrual periods can vary from 1 to 8 days in length. This is usually normal. The average length of the cycle (time between menstrual periods) is about 28 days, but there is no normal cycle length. Some women experience cramping and pain before and during menstruation. "
girls should perform monthly self-exams to check for,(A) breast cancer (B) STIs (C) toxic shock syndrome (D) all of the above,A,"As was discussed in previous concepts, both infectious and noninfectious diseases of the reproductive system can be very serious. But there are ways to keep your reproductive system healthy. What can you do to keep your reproductive system healthy? You can start by making the right choices for overall good health. To be as healthy as you can be, you should: Eat a balanced diet that is high in fiber and low in fat. Drink plenty of water. Get regular exercise. Maintain a healthy weight. Get enough sleep. Avoid using tobacco, alcohol, or other drugs. Manage stress in healthy ways. Keeping your genitals clean is also very important. A daily shower or bath is all that it takes. Females do not need to use special feminine hygiene products. In fact, using them may do more harm than good because they can irritate the vagina or other reproductive structures. You should also avoid other behaviors that can put you at risk. Do not get into contact with another persons blood or other body fluids. For example, never get a tattoo or piercing unless you are sure that the needles have not been used before. This is one of the most important ways to prevent an STI. Of course, the only way to be fully protected against STIs is to refrain from sexual activity. If you are a boy, you should always wear a protective cup when you play contact sports. Contact sports include football, boxing, and hockey. Wearing a cup will help protect the testes from injury. You should also do a monthly self-exam to check for cancer of the testes. If you are a girl and use tampons, be sure to change them every four to six hours. Leaving tampons in for too long can put you at risk of toxic shock syndrome. This is a serious condition. Signs and symptoms of toxic shock syndrome develop suddenly, and the disease can be fatal. The disease involves fever, shock, and problems with the function of several body organs. Girls should also get in the habit of doing a monthly self-exam to check for breast cancer. Although breast cancer is rare in teens, its a good idea to start doing the exam when you are young. It will help you get to know what is normal for you. "
a balanced diet is,(A) high in fat and low in fiber (B) high in fiber and low in protein (C) high in fiber and low in fat (D) high in protein and low in fiber,C,"Physical activity is an important part of balanced eating. It helps you use up any extra Calories in the foods you eat. You should try to get at least an hour of exercise just about every day (see Figure 17.9). Exercise has many health benefits in addition to balancing the energy in food. For example, it strengthens the bones and muscles and may improve your mood. "
"to be as healthy as you can be, you should",(A) get enough sleep (B) avoid tobacco and alcohol (C) exercise on a regular basis (D) all of the above,D,"Your skin is your largest organ and constantly protects you from infections, so keeping your skin healthy is a good idea. "
it is recommended that boys were a protective cup while playing,(A) football (B) baseball (C) and golf (D) b football (E) boxing (F) and hockey (G) c football (H) hockey (I) and skiing (J) d football (K) boxing and wrestling,B,"Maintaining overall good health will help keep your reproductive system healthy. You should eat right, get regular exercise, and follow other healthy lifestyle behaviors. In addition, the following practices will help keep the reproductive system healthy: Keep the genitals clean. A daily shower or bath is all thats needed. Avoid harsh soaps or other personal hygiene products that may be irritating. Avoid risky behaviors. This includes contact with blood or dirty needles as well as sexual activity. If you are a girl and use tampons, be sure to change them every 4 to 6 hours. This will reduce your risk of toxic shock syndrome. This is a very dangerous condition that may occur if tampons are left in too long. If you are a boy, wear a protective cup if you play a contact sport. This will help protect the testes from injury. You should also learn how to check yourself for testicular cancer (see Figure 22.16). You can learn how by watching this video:  MEDIA Click image to the left or use the URL below. URL: "
breathing is controlled by the part of the brain that also controls your heartbeat.,(A) true (B) false,A,"The brain consists of three major parts, called the cerebrum, cerebellum, and brain stem. You can see these three parts of the brain in Figure 20.5. You can use this interactive animation to explore these parts of the brain: http://s 1. The cerebrum is the largest part of the brain. It controls conscious functions, such as thinking, sensing, speaking, and voluntary muscle movements. Whether you are chatting with a friend or playing a video game, you are using your cerebrum. 2. The cerebellum is the next largest part of the brain. It controls body position, coordination, and balance. Hakeems cerebellum kicked in when he started to lose his balance on the railing in the opening photo. It allowed him to regain his balance. 3. The brain stem (also called the medulla) is the smallest part of the brain. It controls involuntary body functions such as breathing, heartbeat, and digestion. It also carries nerve impulses back and forth between the rest of the brain and the spinal cord. "
there is not much more to respiration than just breathing.,(A) true (B) false,B,"The process of getting oxygen into the body and releasing carbon dioxide is called respiration. Sometimes breathing is called respiration, but there is much more to respiration than just breathing. Breathing is only the movement of oxygen into the body and carbon dioxide out of the body. The process of respiration also includes the exchange of oxygen and carbon dioxide between the blood and the cells of the body. "
the main muscle involved in breathing is the,(A) respiratory muscle (B) lung muscle (C) rib muscle (D) diaphragm,D,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
pushing air out of the body through the nose or mouth is,(A) respiration (B) exhalation (C) inhalation (D) breathing,B,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
what is the main gas that is released from the body during respiration?,(A) nitrogen gas (B) oxygen (C) carbon dioxide (D) carbon monoxide,C,"The process of getting oxygen into the body and releasing carbon dioxide is called respiration. Sometimes breathing is called respiration, but there is much more to respiration than just breathing. Breathing is only the movement of oxygen into the body and carbon dioxide out of the body. The process of respiration also includes the exchange of oxygen and carbon dioxide between the blood and the cells of the body. "
where does the exchange of gasses between the lungs and the blood occur?,(A) in the blood (B) in the lungs (C) in the alveoli (D) in the capillaries,C,"The alveoli in the lungs are where gas exchange between the air and blood takes place. Each alveolus is surrounded by a network of capillaries. When you inhale, air in the alveoli has a greater concentration of oxygen than does blood in the capillaries. The difference in oxygen concentration causes oxygen to diffuse from the air into the blood. You can see how this occurs in Figure 19.3. Unlike oxygen, carbon dioxide is more concentrated in the blood in the capillaries surrounding the alveoli than it is in the air inside the alveoli. Therefore, carbon dioxide diffuses in the opposite direction. It moves out of the blood and into the air. "
which of the following are processes of respiration?,(A) The movement of oxygen into the body and carbon dioxide out of the body (B) The exchange of oxygen and carbon dioxide between the blood and the cells of the body (C) The exchange of oxygen and carbon dioxide between the blood and the air passages (D) all of the above,D,"The process of getting oxygen into the body and releasing carbon dioxide is called respiration. Sometimes breathing is called respiration, but there is much more to respiration than just breathing. Breathing is only the movement of oxygen into the body and carbon dioxide out of the body. The process of respiration also includes the exchange of oxygen and carbon dioxide between the blood and the cells of the body. "
the common cold and flu are respiratory illnesses caused by viruses.,(A) true (B) false,A,"Many respiratory diseases are caused by pathogens. A pathogen is an organism that causes disease in another organism. Certain bacteria, viruses, and fungi are pathogens of the respiratory system. The common cold and flu are caused by viruses. The influenza virus that causes the flu is pictured below ( Figure 1.6). Tuberculosis, whooping cough, and acute bronchitis are caused by bacteria. The pathogens that cause colds, flu, and TB can be passed from person to person by coughing, sneezing, and spitting. Illnesses caused by bacteria can be treated with antibiotics. Those caused by viruses cannot. Pollution is another common cause of respiratory disease. The quality of the air you breathe can affect the health of your lungs. Asthma, heart and lung diseases, allergies, and several types of cancers are all linked to air quality. Air pollution is not just found outdoors; indoor air pollution can also be responsible for health problems. Smoking is the major cause of chronic respiratory disease as well as cardiovascular disease and cancer. Exposure to tobacco smoke by smoking or by breathing air that contains tobacco smoke is the leading cause of preventable death in the United States. Regular smokers die about 10 years earlier than nonsmokers do. The Centers for Disease Control and Prevention (CDC) describes tobacco use as ""the single most important preventable risk to human health The lung of a smoker who had emphysema (left). Tar, a sticky, black substance found in tobacco smoke, is evident. Chronic obstructive pulmonary disease (right), is a tobacco-related disease that is characterized by emphysema. This represents the influenza virus that causes the swine flu, or H1N1. The Center for Disease Control and Prevention recommends that children between the ages of 6 months and 19 years get a flu vaccination each year. in developed countries and an important cause of [early] death worldwide."" Simply stated: Stopping smoking can prevent many respiratory diseases. "
stopping smoking can prevent many respiratory diseases.,(A) true (B) false,A,"Cigarette smoking can cause serious diseases, so not smoking or quitting now are the most effective ways to reduce your risk of developing chronic respiratory diseases, such as lung cancer. Avoiding (or stopping) smoking is the single best way to prevent many respiratory and cardiovascular diseases. Also, do your best to avoid secondhand smoke. "
which disease is due to fluid in the alveoli of the lungs?,(A) Bronchitis (B) Asthma (C) Pneumonia (D) Tuberculosis,C,"Common diseases of the respiratory system include asthma, pneumonia, and emphysema. All of them are diseases of the lungs. You can see some of the changes in the lungs that occur in each of these diseases in Figure 19.4. Asthma is a disease in which bronchioles in the lungs periodically swell and fill with mucus. Symptoms of asthma may include difficulty breathing, wheezing, coughing, and chest tightness. An asthma attack may be triggered by allergies, strenuous exercise, stress, or another respiratory illness such as a cold. Pneumonia is a disease in which some of the alveoli of the lungs fill with fluid so they can no longer exchange gas. Symptoms of pneumonia typically include coughing, chest pain, difficulty breathing, and fatigue. Pneumonia may be caused by an infection or an injury to the lungs. Emphysema is a disease in which the walls of the alveoli break down so less gas can be exchanged by the lungs. The main symptom of emphysema is shortness of breath. The damage to the alveoli is usually caused by smoking and is permanent. "
which disease is characterized by coughing up blood?,(A) Tuberculosis (B) Pneumonia (C) Cancer (D) Emphysema,A,"Tuberculosis (TB) is a common and often deadly disease caused by a genus of bacterium called Mycobacterium. Tuberculosis most commonly attacks the lungs but can also affect other parts of the body. TB is a chronic disease, but most people who become infected do not develop the full disease. Symptoms include a cough, which usually contains mucus and coughing up blood. The TB bacteria are spread in the air when people who have the disease cough, sneeze, or spit, so it is very contagious. To help prevent the spread of the disease, public health notices, such as the one pictured below ( Figure 1.3), remind people how to stop the spread of the disease. A public health notice from the early 20th century reminded people that TB could be spread very easily. "
which of the following causes asthma?,(A) warm air (B) cold air (C) or moist air (D) b allergies (E) c exercise (F) d All of the above can cause asthma,D,"Asthma is a chronic illness in which the bronchioles, the tiny branches into which the bronchi are divided, become inflamed and narrow ( Figure 1.2). The muscles around the bronchioles contract, which narrows the airways. Large amounts of mucus are also made by the cells in the lungs. People with asthma have difficulty breathing. Their chests feel tight, and they wheeze. Asthma can be caused by different things, such as allergies. Asthma can also be caused by cold air, warm air, moist air, exercise, or stress. The most common asthma triggers are illnesses, like the common cold. Asthma is not contagious and cannot be passed on to other people. Children and adolescents who have asthma can still lead active lives if they control their asthma. Asthma can be controlled by taking medication and by avoiding contact with environmental triggers for asthma, like smoking. "
which respiratory disease is characterized by the breakdown of lung tissue?,(A) pneumonia (B) tuberculosis (C) emphysema (D) lung cancer,C,"Emphysema is a chronic lung disease caused by the breakdown of the lung tissue. Symptoms of emphysema include shortness of breath, especially during exercise, and chronic cough, usually due to cigarette smoking, and wheezing, especially during expiration. Damage to the alveoli ( Figure 1.5), is not curable. Smoking is the leading cause of emphysema. "
which two severe respiratory illnesses are caused mainly by smoking?,(A) lung cancer and bronchitis (B) lung cancer and emphysema (C) asthma and emphysema (D) emphysema and bronchitis,B,"Cigarette smoking can cause serious diseases, so not smoking or quitting now are the most effective ways to reduce your risk of developing chronic respiratory diseases, such as lung cancer. Avoiding (or stopping) smoking is the single best way to prevent many respiratory and cardiovascular diseases. Also, do your best to avoid secondhand smoke. "
the same things often cause cardiovascular diseases and respiratory diseases.,(A) true (B) false,A,"We know that many respiratory illnesses are caused by bacteria or viruses. There are steps you can take to help the spread of these pathogens, and also to prevent you from catching one. Furthermore, many respiratory illnesses are caused by poor habits, such as smoking. Many of the diseases related to smoking are called lifestyle diseases. Lifestyle diseases are diseases that are caused by choices that people make in their daily lives. For example, the choice to smoke can lead to emphysema, cancer and heart disease in later life. But you can make healthy choices instead. There are many things you can do to keep yourself healthy. "
do not go to school when you are sick.,(A) true (B) false,A,"Do not go to school or to other public places when you are sick. You risk spreading your illness to other people. You may also get even sicker if you catch something else. Do not share food and other things that go in the mouth, as in guzzling milk from the carton or double dipping chips. You never know what pathogens can be lurking around. Cover your mouth with a tissue when you cough or sneeze and to dispose of the tissue yourself. No time to grab a tissue. Cough or sneeze into the inside of your elbow instead of your hands. "
which of the following is an example of a lifestyle diseases?,(A) lung cancer (B) emphysema (C) heart disease (D) all of the above,D,"We know that many respiratory illnesses are caused by bacteria or viruses. There are steps you can take to help the spread of these pathogens, and also to prevent you from catching one. Furthermore, many respiratory illnesses are caused by poor habits, such as smoking. Many of the diseases related to smoking are called lifestyle diseases. Lifestyle diseases are diseases that are caused by choices that people make in their daily lives. For example, the choice to smoke can lead to emphysema, cancer and heart disease in later life. But you can make healthy choices instead. There are many things you can do to keep yourself healthy. "
"getting enough exercise can help keep your respiratory,",(A) cardiovascular (B) and immune systems strong (C) b cardiovascular (D) and nervous systems strong (E) c reproductive (F) and immune systems strong (G) d digestive (H) and immune systems strong,A,"Eating healthy foods, getting enough sleep, and being active every day can help keep your respiratory system, cardiovascular system and immune system strong. Getting enough exercise makes your lungs stronger and better at giving your body the oxygen it needs. It also helps to boost your body fight germs that could make you sick. These can also, of course, keep your skeletal and muscular systems strong. "
"some pathogens can live for up to __________ or more on surfaces like cafeteria tables, doorknobs, and desks.",(A) 2 minutes (B) 20 minutes (C) 2 hours (D) 20 hours,C,"Washing your hands often, especially after sneezing, coughing, or blowing your nose, helps to protect you and others from diseases. Washing your hands for 20 seconds with soap and warm water can help prevent colds and flu. In one respect, you can think of hand washing as a survival skill. Some viruses and bacteria can live from 20 minutes to two hours or more on surfaces like cafeteria tables, doorknobs, and desks. Washing your hands often can remove many of these pathogens. Never touch your mouth, nose, or eyes without washing your hands. "
no time to grab a tissue. what should you do?,(A) Cough or sneeze into the inside of your hands (B) Cough or sneeze into the inside of your elbow (C) Cough or sneeze into your shirt (D) Do not cough or sneeze,B,"Do not go to school or to other public places when you are sick. You risk spreading your illness to other people. You may also get even sicker if you catch something else. Do not share food and other things that go in the mouth, as in guzzling milk from the carton or double dipping chips. You never know what pathogens can be lurking around. Cover your mouth with a tissue when you cough or sneeze and to dispose of the tissue yourself. No time to grab a tissue. Cough or sneeze into the inside of your elbow instead of your hands. "
a yearly flu vaccine is recommended for,(A) people over 65 years old (B) pregnant women (C) only people who get the flu (D) everyone over 6 months old,D,"Getting the recommended vaccinations can help prevent diseases, such as whooping cough and flu. In fact, a yearly flu vaccine is recommended for everyone who is at least 6 months of age. The flu vaccine is especially important for people who are at high risk of developing serious complications (like pneumonia) if they get sick with the flu. People who have certain medical conditions including asthma, diabetes, and chronic lung disease, pregnant women, and people younger than 5 years (and especially those younger than 2), and people 65 years and older should also make sure they get the yearly flu vaccine. Seeking medical help for diseases like asthma can help stop the disease from getting worse. If you are unsure if you should go to the doctor, call the doctors office and ask. "
your nose is an organ of the respiratory system.,(A) true (B) false,A,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
food and air start by going down the same tube.,(A) true (B) false,A,"The pressure of air in the atmosphere allows us to do many things, from sipping through a straw to simply breathing. You can see in the Figures 1.2 and 1.3 how we use air pressure in both of these ways. When you first suck on a straw, you remove air from the straw, so the air pressure in the straw is lower that the air pressure on the surface of the drink. A fluid always flows from an area of higher pressure to an area of lower pressure, so the drink moves up the straw and into your mouth. "
what are components of the upper respiratory tract?,(A) larynx (B) pharynx (C) and trachea (D) b nasal cavity (E) trachea and larynx (F) c lungs (G) bronchi and trachea (H) d nasal cavity (I) pharynx and larynx,D,"You can see the main structures of the respiratory system in Figure 19.1. They include the nose, trachea, lungs, and diaphragm. Use the figure to trace how air moves through the respiratory system when you read about it below. You can also use this interactive to explore the respiratory system and see how it functions: http://science.nationalgeogr "
"what part of the respiratory system serves as a filtering system, keeping certain particles out of the lungs?",(A) the nasal cavity (B) the pharynx (C) the trachea (D) the larynx,A,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
what is the correct order for the passage of air into the lungs?,(A) pharynx then trachea then larynx (B) larynx then pharynx then trachea (C) pharynx then larynx then trachea (D) trachea then larynx then pharynx,C,"Breathing is the process of moving air into and out of the lungs. The process depends on a muscle called the diaphragm. This is a large, sheet-like muscle below the lungs. You can see it in Figure 19.2. Inhaling, or breathing in, occurs when the diaphragm contracts. This increases the size of the chest, which decreases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush into the lungs. Exhaling, or breathing out, occurs when the diaphragm relaxes. This decreases the size of the chest, which increases air pressure inside the lungs. The difference in air pressure between the lungs and outside air causes air to rush out of the lungs. When you inhale, air enters the respiratory system through your nose and ends up in your lungs, where gas exchange with the blood takes place. What happens to the air along the way? In the nose, mucus and hairs trap any dust or other particles in the air. The air is also warmed and moistened so it wont harm delicate tissues of the lungs. Next, air passes through the pharynx, a passageway that is shared with the digestive system. From the pharynx, the air passes next through the larynx, or voice box. After the larynx, air moves into the trachea, or wind pipe. This is a long tube that leads down to the lungs in the chest. In the chest, the trachea divides as it enters the lungs to form the right and left bronchi (bronchus, singular). These passages are covered with mucus and tiny hairs called cilia. The mucus traps any remaining particles in the air. The cilia move and sweep the particles and mucus toward the throat so they can be expelled from the body. Air passes from the bronchi into smaller passages called bronchioles. The bronchioles end in clusters of tiny air sacs called alveoli (alveolus, singular). "
what keeps food out of the lungs?,(A) the trachea (B) the larynx (C) the epiglottis (D) the diaphragm,C,"Your respiratory system is made up of the tissues and organs that allow oxygen to enter your body and carbon dioxide to leave your body. Organs in your respiratory system include your: Nose. Mouth. Larynx. Pharynx. Lungs. Diaphragm. The organs of the respiratory system move air into and out of the body. These structures are shown below (Figure 1.1). What do you think is the purpose of each of these organs? The nose and the nasal cavity filter, warm, and moisten the air you breathe. The nose hairs and the mucus produced by the cells in the nose catch particles in the air and keep them from entering the lungs. Behind the nasal cavity, air passes through the pharynx, a long tube. Both food and air pass through the pharynx. The larynx, also called the ""voice box,"" is found just below the pharynx. Your voice comes from your larynx. Air from the lungs passes across thin tissues in the larynx and produces sound. The trachea, or windpipe, is a long tube that leads down to the lungs, where it divides into the right and left bronchi. The bronchi branch out into smaller bronchioles in each lung. There is small flap called the epiglottis that covers your trachea when you eat or drink. The muscle controlling the epiglottis is involuntary and prevents food from entering your lungs or wind pipe. The bronchioles lead to the alveoli. Alveoli are the little sacs at the end of the bronchioles (Figure 1.2). They look like little bunches of grapes. Oxygen is exchanged for carbon dioxide in the alveoli. That means oxygen enters the blood, and carbon dioxide moves out of the blood. The gases are exchanged between the blood and alveoli by simple diffusion. The diaphragm is a sheet of muscle that spreads across the bottom of the rib cage. When the diaphragm contracts, the chest volume gets larger, and the lungs take in air. When the diaphragm relaxes, the chest volume gets smaller, and air is pushed out of the lungs. ""Grape-like"" alveoli in the lungs. "
how is sound produced?,(A) Air from the lungs passes across tissues in the larynx and produces sound (B) Air from the trachea passes across tissues in the larynx and produces sound (C) Air from the lungs passes across tissues in the pharynx and produces sound (D) Air from the nasal cavity passes across tissues in the pharynx and produces sound,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
"dna is located in the nucleus, and proteins are made in the cytoplasm.",(A) true (B) false,A,"DNA stores genetic information in the cells of all living things. It contains the genetic code. This is the code that instructs cells how to make proteins. The instructions are encoded in the sequence of nitrogen bases in the nucleotide chains of DNA. RNA copies and interprets the genetic code in DNA and is also involved in the synthesis of proteins based on the code. Click image to the left or use the URL below. URL:  Q: DNA is found only in the nucleus of cells, but proteins are synthesized in the cytoplasm of cells, outside of the nucleus. How do you think the instructions encoded in DNA reach the cytoplasm so they can be used to make proteins? A: After RNA copies the instructions in DNA, it carries them from the nucleus to a site of protein synthesis in the cytoplasm, where the instructions are translated into a protein. "
"rna contains the bases a, c, u, and t.",(A) true (B) false,B,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
how is rna different from dna?,(A) RNA is single stranded (B) DNA contains the base uracil (C) RNA has a phosphate group (D) all of the above,A,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
which rna carries information from the nucleus to the cytoplasm?,(A) rRNA (B) tRNA (C) mRNA (D) iRNA,C,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
which rna brings amino acids to the ribosome?,(A) rRNA (B) tRNA (C) mRNA (D) aRNA,B,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
which of the following statements is true?,(A) DNA contains the instructions to make proteins (B) DNA is located in the nucleus (C) DNA needs a messenger to take its instructions to the cytoplasm (D) All of the above are true,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
which of the following statements is true?,(A) mRNA is part of the ribosome (B) tRNA transfers the message to the ribosome (C) rRNA relays amino acids to the ribosome (D) mRNA is made in the nucleus,D,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
some worms can have six lips.,(A) true (B) false,A,"The word ""worm"" is not very scientific. This informal term describes animals (usually invertebrates) that have long bodies with no arms or legs. Worms with round, non-segmented bodies are known as nematodes or roundworms ( Figure 1.1). They are classified in the phylum Nematoda, which has over 28,000 known species. Some scientists believe there could be over a million species of Nematodes. Nematodes are slender bilaterally symmetrical worms, typically less than 2.5 mm long. The smallest nematodes are microscopic, while free-living species can reach as much as 5 cm, and some parasitic species are larger still, reaching over a meter in length. The worm body is often covered with ridges, rings, bristles, or other distinctive structures. The radially symmetrical head of a nematode also has distinct features. The head is covered with sensory bristles and, in many cases, solid ""head-shields"" around the mouth region. The mouth has either three or six lips arranged around the mouth opening, which often have a series of teeth on their inner edges. Nematodes can be parasites of plants and animals. "
most nematodes are harmful.,(A) true (B) false,A,"The word ""worm"" is not very scientific. This informal term describes animals (usually invertebrates) that have long bodies with no arms or legs. Worms with round, non-segmented bodies are known as nematodes or roundworms ( Figure 1.1). They are classified in the phylum Nematoda, which has over 28,000 known species. Some scientists believe there could be over a million species of Nematodes. Nematodes are slender bilaterally symmetrical worms, typically less than 2.5 mm long. The smallest nematodes are microscopic, while free-living species can reach as much as 5 cm, and some parasitic species are larger still, reaching over a meter in length. The worm body is often covered with ridges, rings, bristles, or other distinctive structures. The radially symmetrical head of a nematode also has distinct features. The head is covered with sensory bristles and, in many cases, solid ""head-shields"" around the mouth region. The mouth has either three or six lips arranged around the mouth opening, which often have a series of teeth on their inner edges. Nematodes can be parasites of plants and animals. "
how many species of parasitic roundworms have been identified?,(A) about 1 (B) 600 (C) b about 1 (D) 6000 (E) c about 28 (F) 000 (G) d over 150 (H) 000,A,"Roundworms are invertebrates in Phylum Nematoda. This is a very diverse phylum. It has more than 80,000 known species. Roundworms range in length from less than 1 millimeter to over 7 meters in length. You can see an example of a roundworm in Figure 12.13. "
which best describes the nematode digestive system?,(A) A complete digestive system (B) with both a mouth and an anus (C) b A complete digestive system (D) with just a mouth (E) c An incomplete digestive system (F) with just a mouth (G) d An incomplete digestive system (H) with both a mouth and an anus,A,"Even early invertebrates had a digestive system. However, the earliest digestive system was incomplete. There was just one opening for food to enter the body and waste to leave the body. In other words, the same opening was both mouth and anus. A modern jellyfish has this type of digestive system, as shown in Figure 11.8. Eventually a complete digestive system with two body openings evolved, as shown in Figure 11.8. With a separate mouth and anus, food could move through the body in just one direction. This made digestion more efficient. An animal could keep eating while digesting food and getting rid of waste. Different parts of the digestive tract could also become specialized for different digestive functions. This led to the evolution of digestive organs. Modern animals that represent this stage of evolution are roundworms. They are placed in Phylum Nematoda. "
which best describes the nematode brain?,(A) a circular cluster of nervous tissue (B) a nerve net attaching at the head region (C) a circular ring of nerves (D) None of the above describe the nematode brain,C,"The word ""worm"" is not very scientific. This informal term describes animals (usually invertebrates) that have long bodies with no arms or legs. Worms with round, non-segmented bodies are known as nematodes or roundworms ( Figure 1.1). They are classified in the phylum Nematoda, which has over 28,000 known species. Some scientists believe there could be over a million species of Nematodes. Nematodes are slender bilaterally symmetrical worms, typically less than 2.5 mm long. The smallest nematodes are microscopic, while free-living species can reach as much as 5 cm, and some parasitic species are larger still, reaching over a meter in length. The worm body is often covered with ridges, rings, bristles, or other distinctive structures. The radially symmetrical head of a nematode also has distinct features. The head is covered with sensory bristles and, in many cases, solid ""head-shields"" around the mouth region. The mouth has either three or six lips arranged around the mouth opening, which often have a series of teeth on their inner edges. Nematodes can be parasites of plants and animals. "
how do roundworms get rid of waste?,(A) Through the one opening of the gastrovascular cavity (B) Through the anus at the end of the digestive tract (C) Through the mouth (D) which serves to both ingest food and expel waste (E) d all of the above,B,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
factors contributing to parasitic roundworm diseases include,(A) crowded living conditions (B) inadequate sanitation measures (C) lack of a clean water supply (D) all of the above,D,"Roundworms can be free-living organisms, but they are probably best known for their role as significant plant and animal parasites. Most Nematodes are parasitic, with over 16,000 parasitic species described. Heartworms, which cause serious disease in dogs while living in the heart and blood vessels, are a type of roundworm. Roundworms can also cause disease in humans. Elephantiasis, a disease characterized by the extreme swelling of the limbs ( Figure Most parasitic roundworm eggs or larvae are found in the soil and enter the human body when a person picks them up on the hands and then transfers them to the mouth. The eggs or larvae also can enter the human body directly through the skin. The best solution to these diseases is to try to prevent these diseases rather than treat or cure them. Diseases caused by roundworms are more common in developing countries. Many parasitic diseases caused by roundworms result from poor personal hygiene. Contributing factors may include lack of a clean water supply, inadequate sanitation measures, crowded living conditions, combined with a lack of access to health care and low levels of education. "
most segmented worms feed on dead organic matter.,(A) true (B) false,A,"When you think of worms, you probably picture earthworms. There are actually many types of worms, including flatworms, roundworms, and segmented worms. Earthworms are segmented worms. Segmented worms are in the phylum Annelida, which has over 22,000 known species. These worms are known as the segmented worms because their bodies are segmented, or separated into repeating units. Besides the earthworm, the segmented worms also include leeches and some marine worms. Most segmented worms like the earthworm, feed on dead organic matter. Leeches (Figure 1.1), however, can live in fresh water and suck blood from their animal host. You may have noticed many earthworms in soil. Earthworms support terrestrial ecosystems both as prey and by aerating and enriching soil. "
the leech is a segmented worm that feeds on live blood.,(A) true (B) false,A,"Annelids live in a diversity of freshwater, salt-water, and terrestrial habitats. They vary in what they eat and how they get their food. Some annelids, such as earthworms, eat soil and extract organic material from it. Annelids called leeches are either predators or parasites. Some leeches capture and eat other invertebrates. Others feed off the blood of vertebrate hosts. Annelids called polychaete worms live on the ocean floor. They may be filter feeders, predators, or scavengers. The amazing feather duster worm in Figure 12.19 is a polychaete that has a fan-like crown of tentacles for filter feeding. "
worm parapodia serve what function?,(A) touch (B) locomotion (C) feeding (D) sight,B,"The pauropods are typically 0.5-2.0 mm long and live on all continents except Antarctica. They are usually found in soil, leaf litter, or other moist places. They feed on fungi and decaying organic matter, and are essentially harmless. Adult pauropods have 11 or 12 body segments and 9-11 pairs of legs. They also possess unique forked antennae and a distinctive pattern of movement characterized by rapid burst of movement and frequent abrupt changes in direction. Over 700 species have been described, and they are believed to be closely related to millipedes. "
which best describes the digestive tract of an annelid?,(A) Incomplete digestive tract with two openings (B) intestines and a stomach (C) b Incomplete digestive tract with one opening (D) an esophagus and a stomach (E) c Complete digestive tract with two openings (F) an esophagus and intestines (G) d Complete digestive tract with one opening (H) an esophagus and intestines,C,"Even early invertebrates had a digestive system. However, the earliest digestive system was incomplete. There was just one opening for food to enter the body and waste to leave the body. In other words, the same opening was both mouth and anus. A modern jellyfish has this type of digestive system, as shown in Figure 11.8. Eventually a complete digestive system with two body openings evolved, as shown in Figure 11.8. With a separate mouth and anus, food could move through the body in just one direction. This made digestion more efficient. An animal could keep eating while digesting food and getting rid of waste. Different parts of the digestive tract could also become specialized for different digestive functions. This led to the evolution of digestive organs. Modern animals that represent this stage of evolution are roundworms. They are placed in Phylum Nematoda. "
which describes the segmented worm circulatory system?,(A) a complete heart and blood vessels (B) five paired hearts and blood vessels (C) five two chamber hearts and blood (D) blood and blood vessels,B,"Segmented worms have a number of characteristic features. 1. The basic form consists of multiple segments, each of which has the same sets of organs and, in most, a pair of parapodia that many species use for locomotion. 2. Segmented worms have a well-developed body cavity filled with fluid. This fluid-filled cavity serves as a hydroskeleton, a supportive structure that helps move the worms muscles. Only the most primitive worms (the flatworms) lack a body cavity. 3. Segmented worms also tend to have organ systems that are more developed than the roundworms or flat- worms. Earthworms, for example, have a complete digestive tract with two openings, as well as an esophagus and intestines. The circulatory system consists of paired hearts and blood vessels. Actually there are five pairs of hearts that pump blood along the two main vessels. And the nervous system consists of the brain and a ventral nerve cord. "
which worms have a body cavity?,(A) flatworm and roundworm (B) roundworm and segmented worm (C) segmented worm and flatworm (D) all three phyla,B,"Roundworms have a round body because they have a partial fluid-filled body cavity (pseudocoelom). This is one way that roundworms differ from flatworms. Another way is their complete digestive system. It allows them to eat, digest food, and eliminate wastes all at the same time. Roundworms have a tough covering of cuticle on the surface of their body. It prevents their body from expanding. This allows the buildup of fluid pressure in their partial body cavity. The fluid pressure adds stiffness to the body. This provides a counterforce for the contraction of muscles, allowing roundworms to move easily over surfaces. "
which worms have a complete digestive system?,(A) flatworm and roundworm (B) roundworm and segmented worm (C) segmented worm and flatworm (D) all three phyla,B,"1. Unlike the flatworms, the roundworms have a body cavity with internal organs. 2. A roundworm has a complete digestive system, which includes both a mouth and an anus. This is a significant difference from the incomplete digestive system of flatworms. The roundworm digestive system also include a large digestive organ known as the gut. Digestive enzymes that start to break down food are produced here. There is no stomach, but there is an intestine which produces enzymes that help absorb nutrients. The last portion of the intestine forms a rectum, which expels waste through the anus. 3. Roundworms also have a simple nervous system with a primitive brain. There are four nerves that run the length of the body and are connected from the top to the bottom of the body. At the anterior end of the animal (the head region), the nerves branch from a circular ring which serves as the brain. The head of a nematode has a few tiny sense organs, including chemoreceptors, which sense chemicals. Though still a relatively simple structure, the nervous system of roundworms is very different from that of the cnidarian nerve net. "
the mother determines the sex of her baby.,(A) true (B) false,B,"What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomesand one of those pairs is the sex chromosomes. Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the childs sex? The baby will have two X chromosomes, so it will be female. If the fathers sperm carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couples first five children could all be boys. The sixth child still has a 50:50 chance of being a girl. One special pattern of inheritance that doesnt fit Mendels rules is sex-linked inheritance, referring to the inher- itance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traitstraits linked to genes located on the sex chromosomesare expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome. One example of a sex-linked trait is red-green colorblindness. People with this type of colorblindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure 1.1). Boys are much more likely to be colorblind than girls ( Table 1.1). This is because colorblindness is a sex-linked, recessive trait. Boys only have one X chromosome, so if that chromosome carries the gene for colorblindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color vision. Since colorblindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one colorblindness allele and one normal allele are referred to as carriers. They carry the allele but do not express it. How would a female become colorblind? She would have to inherit two genes for colorblindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner. Xc Xc X (carrier female) Xc Y (colorblind male) X Y X XX (normal female) XY (normal male) According to this Punnett square ( Table 1.1), the son of a woman who carries the colorblindness trait and a male with normal vision has a 50% chance of being colorblind. "
females have two x chromosomes.,(A) true (B) false,A,"In people, the sex chromosomes are called X and Y chromosomes. Individuals with two X chromosomes are normally females. Individuals with one X and one Y chromosome are normally males. As you can see in Figure sons. "
a couple has already had three daughters. what is the chance that the next baby will be a boy?,(A) 0% (B) 25% (C) 50% (D) 100%,A,"What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomesand one of those pairs is the sex chromosomes. Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the childs sex? The baby will have two X chromosomes, so it will be female. If the fathers sperm carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couples first five children could all be boys. The sixth child still has a 50:50 chance of being a girl. One special pattern of inheritance that doesnt fit Mendels rules is sex-linked inheritance, referring to the inher- itance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traitstraits linked to genes located on the sex chromosomesare expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome. One example of a sex-linked trait is red-green colorblindness. People with this type of colorblindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure 1.1). Boys are much more likely to be colorblind than girls ( Table 1.1). This is because colorblindness is a sex-linked, recessive trait. Boys only have one X chromosome, so if that chromosome carries the gene for colorblindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color vision. Since colorblindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one colorblindness allele and one normal allele are referred to as carriers. They carry the allele but do not express it. How would a female become colorblind? She would have to inherit two genes for colorblindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner. Xc Xc X (carrier female) Xc Y (colorblind male) X Y X XX (normal female) XY (normal male) According to this Punnett square ( Table 1.1), the son of a woman who carries the colorblindness trait and a male with normal vision has a 50% chance of being colorblind. "
a colorblind male marries a carrier female. what is the chance that their child will be colorblind?,(A) 0% (B) 25% (C) 50% (D) 100%,A,"What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomesand one of those pairs is the sex chromosomes. Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the childs sex? The baby will have two X chromosomes, so it will be female. If the fathers sperm carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couples first five children could all be boys. The sixth child still has a 50:50 chance of being a girl. One special pattern of inheritance that doesnt fit Mendels rules is sex-linked inheritance, referring to the inher- itance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traitstraits linked to genes located on the sex chromosomesare expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome. One example of a sex-linked trait is red-green colorblindness. People with this type of colorblindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure 1.1). Boys are much more likely to be colorblind than girls ( Table 1.1). This is because colorblindness is a sex-linked, recessive trait. Boys only have one X chromosome, so if that chromosome carries the gene for colorblindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color vision. Since colorblindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one colorblindness allele and one normal allele are referred to as carriers. They carry the allele but do not express it. How would a female become colorblind? She would have to inherit two genes for colorblindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner. Xc Xc X (carrier female) Xc Y (colorblind male) X Y X XX (normal female) XY (normal male) According to this Punnett square ( Table 1.1), the son of a woman who carries the colorblindness trait and a male with normal vision has a 50% chance of being colorblind. "
a normal male marries a carrier female. what is the chance that their child will be colorblind?,(A) 0 (B) 25% (C) 50% (D) 100%,B,"What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomesand one of those pairs is the sex chromosomes. Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the childs sex? The baby will have two X chromosomes, so it will be female. If the fathers sperm carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couples first five children could all be boys. The sixth child still has a 50:50 chance of being a girl. One special pattern of inheritance that doesnt fit Mendels rules is sex-linked inheritance, referring to the inher- itance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traitstraits linked to genes located on the sex chromosomesare expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome. One example of a sex-linked trait is red-green colorblindness. People with this type of colorblindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure 1.1). Boys are much more likely to be colorblind than girls ( Table 1.1). This is because colorblindness is a sex-linked, recessive trait. Boys only have one X chromosome, so if that chromosome carries the gene for colorblindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color vision. Since colorblindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one colorblindness allele and one normal allele are referred to as carriers. They carry the allele but do not express it. How would a female become colorblind? She would have to inherit two genes for colorblindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner. Xc Xc X (carrier female) Xc Y (colorblind male) X Y X XX (normal female) XY (normal male) According to this Punnett square ( Table 1.1), the son of a woman who carries the colorblindness trait and a male with normal vision has a 50% chance of being colorblind. "
a colorblind male marries a normal female. which statement is correct?,(A) All their daughters will be carriers (B) All their sons will be colorblind (C) Half of their daughters will be normal (D) Both (a,A,"What determines if a baby is a male or female? Recall that you have 23 pairs of chromosomesand one of those pairs is the sex chromosomes. Everyone has two sex chromosomes. Your sex chromosomes can be X or Y. Females have two X chromosomes (XX), while males have one X chromosome and one Y chromosome (XY). If a baby inherits an X chromosome from the father and an X chromosome from the mother, what will be the childs sex? The baby will have two X chromosomes, so it will be female. If the fathers sperm carries the Y chromosome, the child will be male. Notice that a mother can only pass on an X chromosome, so the sex of the baby is determined by the father. The father has a 50 percent chance of passing on the Y or X chromosome, so there is a 50 percent chance that a child will be male, and there is a 50 percent chance a child will be female. This 50:50 chance occurs for each baby. A couples first five children could all be boys. The sixth child still has a 50:50 chance of being a girl. One special pattern of inheritance that doesnt fit Mendels rules is sex-linked inheritance, referring to the inher- itance of traits that are located on genes on the sex chromosomes. Since males and females do not have the same sex chromosomes, there will be differences between the sexes in how these sex-linked traitstraits linked to genes located on the sex chromosomesare expressed. Sex-linked traits usually refer to traits due to genes on the X chromosome. One example of a sex-linked trait is red-green colorblindness. People with this type of colorblindness cannot tell the difference between red and green. They often see these colors as shades of brown ( Figure 1.1). Boys are much more likely to be colorblind than girls ( Table 1.1). This is because colorblindness is a sex-linked, recessive trait. Boys only have one X chromosome, so if that chromosome carries the gene for colorblindness, they will be colorblind. As girls have two X chromosomes, a girl can have one X chromosome with the colorblind gene and one X chromosome with a normal gene for color vision. Since colorblindness is recessive, the dominant normal gene will mask the recessive colorblind gene. Females with one colorblindness allele and one normal allele are referred to as carriers. They carry the allele but do not express it. How would a female become colorblind? She would have to inherit two genes for colorblindness, which is very unlikely. Many sex-linked traits are inherited in a recessive manner. Xc Xc X (carrier female) Xc Y (colorblind male) X Y X XX (normal female) XY (normal male) According to this Punnett square ( Table 1.1), the son of a woman who carries the colorblindness trait and a male with normal vision has a 50% chance of being colorblind. "
most sex-linked genes are ___________.,(A) dominant (B) recessive (C) incompletely dominant (D) codominant,B,"Traits controlled by genes on the sex chromosomes are called sex-linked traits. One gene on the Y chromosome determines male sex. There are very few other genes on the Y chromosome, which is the smallest human chromo- some. There are hundreds of genes on the much larger X chromosome. None is related to sex. Traits controlled by genes on the X chromosome are called X-linked traits. X-linked traits have a different pattern of inheritance than traits controlled by genes on autosomes. With just one X chromosome, males have only one allele for any X-linked trait. Therefore, a recessive X-linked allele is always expressed in males. With two X chromosomes, females have two alleles for any X-linked trait, just as they do for autosomal traits. Therefore, a recessive X-linked allele is expressed in females only when they inherit two copies of it. This explains why X-linked recessive traits show up less often in females than males. "
"many stis do not cause symptoms, especially in females.",(A) true (B) false,A,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
all stis can be cured.,(A) true (B) false,B,"Several STIs are caused by viruses. Viral STIs cant be cured with antibiotics. Other drugs may help control the symptoms of viral STIs, but the infections usually last for life. Three viral STIs are genital warts, genital herpes, and AIDS. Genital herpes is a common STI caused by a herpes virus. The virus causes painful blisters on the penis or near the vaginal opening. The blisters generally go away on their own, but they may return repeatedly throughout life. There is no cure for genital herpes, but medicines can help prevent or shorten outbreaks. Acquired Immunodeficiency Syndrome (AIDS) is caused by human immunodeficiency virus (HIV). HIV destroys lymphocytes that normally fight infections. AIDS develops if the number of lymphocytes drops to a very low level. People with AIDS come down with diseasessuch as certain rare cancersthat almost never occur in people with a healthy immune system. Medicines can delay the progression of an HIV infection and may prevent AIDS from developing. Genital warts is an STI caused by human papilloma virus (HPV), which is pictured in Figure 22.15. This is one of the most common STIs in U.S. teens. Genital warts cant be cured, but a vaccine can prevent most HPV infections. The vaccine is recommended for boys and girls starting at 11 or 12 years of age. Its important to prevent HPV infections because they may lead to cancer later in life. "
this sti may cause pain during urination.,(A) gonorrhea (B) syphilis (C) hepatitis B (D) HIV,A,"In the U.S., chlamydia is the most common STI caused by bacteria. Females are more likely than males to develop the infection. Rates of chlamydia among U.S. females in 2006 are shown below ( Figure 1.1). Rates were much higher in teens and young women than in other age groups. Chlamydia may cause a burning feeling during urination. It may also cause a discharge (leaking of fluids) from the vagina or penis. But in many cases it causes no symptoms. As a result, people do not know they are infected, so they dont go to the doctor for help. If chlamydia goes untreated, it may cause more serious problems in females. It may cause infections of the uterus, fallopian tubes, or ovaries. These infections may leave a woman unable to have children. Gonorrhea is another common STI. Gonorrhea may cause pain during urination. It may also cause a discharge from the vagina or penis. On the other hand, some people with gonorrhea have no symptoms. As a result, they dont seek treatment. Without treatment, gonorrhea may lead to infection of other reproductive organs. This can happen in males as well as females. Syphilis is a very serious STI. Luckily, it is less common than chlamydia or gonorrhea. Syphilis usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis is not treated, it may damage the heart, brain, and other organs. It can even cause death. "
this sti is very serious and will cause death without treatment.,(A) gonorrhea (B) syphilis (C) HPV (D) HIV,D,"A sexually transmitted infection (STI) is an infection that spreads through sexual contact. STIs are caused by pathogens, a living thing or virus that causes infection. The pathogens enter the body through the reproductive organs. Many STIs also spread through body fluids, such as blood. For example, a shared tattoo needle is one way an STI could spread. Some STIs can also spread from a mother to her baby during childbirth. STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to take risks. They also may not know how STIs spread. They are likely to believe myths about STIs ( Table Myth If you are sexually active with just one person, you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because STIs can be cured with medicine. Fact The only way to avoid the risk of STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicine; other STIs cannot be cured. Most STIs are caused by bacteria or viruses. STIs caused by bacteria usually can be cured with drugs called antibiotics. But antibiotics are not effective against viruses. Therefore, STIs caused by viruses are not treated with antibiotics. Other drugs may be used to help control the symptoms of viral STIs, but they cannot be cured. Once you have a viral STI, you are usually infected for life. "
this sti usually begins with a small sore on the genitals.,(A) gonorrhea (B) syphilis (C) hepatitis B (D) HIV,B,"A number of STIs are caused by bacteria. Bacterial STIs can usually be cured with antibiotics. However, some people with bacterial STIs may not have symptoms so they fail to get treatment. Left untreated, these infections may damage reproductive organs and lead to an inability to have children. Three bacterial STIs are chlamydia, gonorrhea, and syphilis. Chlamydia is the most common bacterial STI in the U.S. Females are more likely to develop it than males. Symptoms may include burning during urination and a discharge from the vagina or penis. Gonorrhea is another common bacterial STI. Symptoms may include painful urination and a discharge from the vagina or penis. Syphilis is a very serious STI but somewhat less common than chlamydia or gonorrhea. It usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis isnt treated, it can eventually damage the heart, brain, and other organs and even cause death. "
this sti causes yellowing of the skin and eyes.,(A) gonorrhea (B) syphilis (C) hepatitis B (D) HPV,C,"In the U.S., chlamydia is the most common STI caused by bacteria. Females are more likely than males to develop the infection. Rates of chlamydia among U.S. females in 2006 are shown below ( Figure 1.1). Rates were much higher in teens and young women than in other age groups. Chlamydia may cause a burning feeling during urination. It may also cause a discharge (leaking of fluids) from the vagina or penis. But in many cases it causes no symptoms. As a result, people do not know they are infected, so they dont go to the doctor for help. If chlamydia goes untreated, it may cause more serious problems in females. It may cause infections of the uterus, fallopian tubes, or ovaries. These infections may leave a woman unable to have children. Gonorrhea is another common STI. Gonorrhea may cause pain during urination. It may also cause a discharge from the vagina or penis. On the other hand, some people with gonorrhea have no symptoms. As a result, they dont seek treatment. Without treatment, gonorrhea may lead to infection of other reproductive organs. This can happen in males as well as females. Syphilis is a very serious STI. Luckily, it is less common than chlamydia or gonorrhea. Syphilis usually begins with a small sore on the genitals. This is followed a few months later by a rash and flu-like symptoms. If syphilis is not treated, it may damage the heart, brain, and other organs. It can even cause death. "
which of the following is one of the most common stis in teenagers?,(A) genital herpes (B) genital warts (C) gonorrhea (D) syphilis,B,"STIs are more common in teens and young adults than in older people. One reason is that young people are more likely to engage in risky behaviors. They also may not know how STIs spread. Instead, they may believe myths about STIs, like those in Table 22.1. Knowing the facts is important to prevent the spread of STIs. Myth If you are sexually active with just one person, then you cant get STIs. If you dont have any symptoms, then you dont have an STI. Getting STIs is no big deal, because they can be cured with medicines. Fact The only sure way to avoid getting STIs is to practice abstinence from sexual activity. Many STIs do not cause symptoms, especially in fe- males. Only some STIs can be cured with medicines; others cannot be cured. "
joint pain is a common problem as people age.,(A) true (B) false,A,"Osteoarthritis occurs when the cartilage at the ends of the bones breaks down. The break down of the cartilage leads to pain and stiffness in the joint. Decreased movement of the joint because of the pain may lead to weakening of the muscles that normally move the joint, and the ligaments surrounding the joint may become loose. Osteoarthritis is the most common form of arthritis. It has many contributing factors, including aging, sport injuries, fractures, and obesity. "
all joints allow bones to move.,(A) true (B) false,B,"A joint is a place where two or more bones of the skeleton meet. There are three different types of joints based on the degree to which they allow movement of the bones: immovable, partly movable, and movable joints. Immovable joints do not allow the bones to move at all. In these joints, the bones are fused together by very tough collagen. Examples of immovable joints include the joints between bones of the skull. You can see them in Figure 16.12. Partly movable joints allow very limited movement. In these joints, the bones are held together by cartilage, which is more flexible than collagen. Examples of partly moveable joints include the bones of the rib cage. Movable joints allow the greatest movement and are the most common. In these joints, the bones are connected by ligaments. The surfaces of the bones at the joints are covered with a smooth layer of cartilage. It reduces friction between the bones when they move. The space between the bones is also filled with a liquid called synovial fluid. It helps to cushion the bones. There are several different types of movable joints. You can see three of them in Figure 16.13. Move these three joints in your own skeleton to experience the range of motion each allows. "
which is an example of a ball-and-socket joint?,(A) shoulder (B) knee (C) ankle (D) in forearm,A,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
what type of joint allows you to turn the palm of your hand?,(A) a ball-and-socket joint (B) a hinge joint (C) a pivot joint (D) a gliding joint,C,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
what type of joint allows forward and backward movement?,(A) a ball-and-socket joint (B) a hinge joint (C) a pivot joint (D) a gliding joint,B,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
where are gliding joints located?,(A) hip and shoulder (B) knees (C) elbow (D) wrists and ankles,D,"Four types of movable joints are discussed here. 1. In a ball-and-socket joint, the ball-shaped surface of one bone fits into the cup-like shape of another. Exam- ples of a ball-and-socket joint include the hip ( Figure 1.3) and the shoulder. 2. In a hinge joint, the ends of the bones are shaped in a way that allows motion in two directions, forward and backward. Examples of hinge joints are the knees ( Figure 1.4) and elbows. 3. The pivot joint ( Figure 1.5) only allows rotating movement. An example of a pivot joint is the joint between the radius and ulna that allows you to turn the palm of your hand up and down. 4. A gliding joint is a joint which allows only gliding movement. The gliding joint allows one bone to slide over the other. The gliding joint in your wrist allows you to flex your wrist. It also allows you to make very small side-to-side motions. There are also gliding joints in your ankles. "
your skin is the largest organ in your body.,(A) true (B) false,A,"Your skin is your largest organ and constantly protects you from infections, so keeping your skin healthy is a good idea. "
the layer of skin you can see is actually dead cells.,(A) true (B) false,A,"Your skin is always exposed to your external environment, so it gets cut, scratched, and worn down. You also naturally shed many skin cells every day. Your body replaces damaged or missing skin cells by growing more of them. Did you know that the layer of skin you can see is actually dead? As the dead cells are shed or removed from the upper layer, they are replaced by the skin cells below them. Two different layers make up the skin: the epidermis and the dermis ( Figure 1.2). A fatty layer lies under the dermis, but it is not part of your skin. "
how does skin control body temperature?,(A) by keeping water from leaving the body (B) by sensing heat and cold (C) by making and releasing perspiration (D) all of the above,C,"The skin has many important functions. The skin: Provides a barrier. It keeps organisms that could harm the body out. It stops water from entering or leaving the body. Controls body temperature. It does this by making sweat (or perspiration), a watery substance that cools the body when it evaporates. Gathers information about your environment. Special nerve endings in your skin sense heat, pressure, cold, and pain. Helps the body get rid of some types of waste, which are removed in sweat. Acts as a sun block. A pigment called melanin blocks sunlight from getting to deeper layers of skin cells, which are easily damaged by sunlight. "
which statement is true about the epidermis?,(A) The epidermis is made of tough connective tissue (B) The epidermis forms the waterproof (C) protective wrap over the body's surface (D) c The epidermis contains hair follicles and sweat glands (E) d All of the above describe the epidermis,B,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
how does skin act as a sun block?,(A) Melanin blocks sunlight from getting to deeper layers of skin cells (B) Special nerve endings in your skin sense heat (C) blocking out sunlight (D) c Natural perspiration washes away sunlight (E) d Skin has natural spf 15 material built in,A,"The skin has many important functions. The skin: Provides a barrier. It keeps organisms that could harm the body out. It stops water from entering or leaving the body. Controls body temperature. It does this by making sweat (or perspiration), a watery substance that cools the body when it evaporates. Gathers information about your environment. Special nerve endings in your skin sense heat, pressure, cold, and pain. Helps the body get rid of some types of waste, which are removed in sweat. Acts as a sun block. A pigment called melanin blocks sunlight from getting to deeper layers of skin cells, which are easily damaged by sunlight. "
which statement is true about the outermost layers of skin?,(A) The outermost layers are composed of 25 to 30 layers of cells (B) The outermost layers are made of dead cells (C) Live cells from underneath move upward to replace shed cells (D) All of the above are true,D,"The epidermis is the outermost layer of the skin. It forms the waterproof, protective wrap over the bodys surface. Although the top layer of epidermis is only about as thick as a sheet of paper, it is made up of 25 to 30 layers of cells. The epidermis also contains cells that produce melanin. Melanin is the brownish pigment that gives skin and hair their color. Melanin-producing cells are found in the bottom layer of the epidermis. The epidermis does not have any blood vessels. The lower part of the epidermis receives blood by diffusion from blood vessels of the dermis. Skin is made up of two layers, the epider- mis on top and the dermis below. The tissue below the dermis is called the hy- podermis, but it is not part of the skin. "
"how does skin release excess water and get rid of wastes such as ammonia, urea, salts, and sugar.",(A) through melanin (B) through sebum (C) through sweat (D) through special nerve endings,C,"So what happens to your bodys wastes? Obviously, you must get rid of them. This is the job of the excretory system. You remove waste as a gas (carbon dioxide), as a liquid (urine and sweat), and as a solid. Excretion is the process of removing wastes and excess water from the body. Recall that carbon dioxide travels through the blood and is transferred to the lungs where it is exhaled. In the large intestine, the remains of food are turned into solid waste for excretion. How is waste other than carbon dioxide removed from the blood? That is the role of the kidneys. Urine is a liquid waste formed by the kidneys as they filter the blood. If you are getting plenty of fluids, your urine should be almost clear. But you might have noticed that sometimes your urine is darker than usual. Do you know why this happens? Sometimes your body is low on water and trying to reduce the amount of water lost in urine. Therefore, your urine gets darker than usual. Your body is striving to maintain homeostasis through the process of excretion. Urine helps remove excess water, salts, and nitrogen from your body. Your body also needs to remove the wastes that build up from cell activity and from digestion. If these wastes are not removed, your cells can stop working, and you can get very sick. The organs of your excretory system help to release wastes from the body. The organs of the excretory system are also parts of other organ systems. For example, your lungs are part of the respiratory system. Your lungs remove carbon dioxide from your body, so they are also part of the excretory system. More organs of the excretory system are listed below ( Table 1.1). Organ(s) Function Lungs Skin Remove carbon dioxide. Sweat glands remove water, salts, and other wastes. Removes solid waste and some wa- ter in the form of feces. Remove urea, salts, and excess wa- ter from the blood. Large intestine Kidneys Component of Other Organ Sys- tem Respiratory system Integumentary system Digestive system Urinary system "
your body has only three types of muscles.,(A) true (B) false,A,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
you cannot stop a reflex muscle contraction.,(A) true (B) false,A,"The muscular system consists of all the muscles in the body. This is the body system that allows us to move. You also depend on many muscles to keep you alive. Your heart, which is mostly muscle, pumps blood around your body. Each muscle in the body is made up of cells called muscle fibers. Muscle fibers are long, thin cells that can do something that other cells cannot dothey are able to get shorter. Shortening of muscle fibers is called contraction. Muscle fibers can contract because they are made of proteins, called actin and myosin, that form long filaments (or fibers). When muscles contract, these protein filaments slide or glide past one another, shortening the length of the cell. When your muscles relax, the length extends back to the previous position. Nearly all movement in the body is the result of muscle contraction. You can control some muscle movements. However, certain muscle movements happen without you thinking about them. Muscles that are under your conscious control are called voluntary muscles. Muscles that are not under your conscious control are called involuntary muscles. Muscle tissue is one of the four types of tissue found in animals. There are three different types of muscle in the body ( Figure 1.1): 1. Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. 2. Smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. These muscles push materials like food or blood through organs. Unlike skeletal muscle, smooth muscle can never be under your control. 3. Cardiac muscle is also an involuntary muscle, found only in the heart. The cardiac muscle fibers all contract together, generating enough force to push blood throughout the body. What would happen if this muscle was under conscious or voluntary control? There are three types of muscles in the body: cardiac, skeletal, and smooth. "
what muscles are not under voluntary control?,(A) skeletal muscle and smooth muscle (B) skeletal muscle and cardiac muscle (C) cardiac muscle and smooth muscle (D) bone muscle and heart muscle,C,"The muscular system consists of all the muscles in the body. This is the body system that allows us to move. You also depend on many muscles to keep you alive. Your heart, which is mostly muscle, pumps blood around your body. Each muscle in the body is made up of cells called muscle fibers. Muscle fibers are long, thin cells that can do something that other cells cannot dothey are able to get shorter. Shortening of muscle fibers is called contraction. Muscle fibers can contract because they are made of proteins, called actin and myosin, that form long filaments (or fibers). When muscles contract, these protein filaments slide or glide past one another, shortening the length of the cell. When your muscles relax, the length extends back to the previous position. Nearly all movement in the body is the result of muscle contraction. You can control some muscle movements. However, certain muscle movements happen without you thinking about them. Muscles that are under your conscious control are called voluntary muscles. Muscles that are not under your conscious control are called involuntary muscles. Muscle tissue is one of the four types of tissue found in animals. There are three different types of muscle in the body ( Figure 1.1): 1. Skeletal muscle is made up of voluntary muscles, usually attached to the skeleton. Skeletal muscles move the body. They can also contract involuntarily by reflexes. For example, you can choose to move your arm, but your arm would move automatically if you were to burn your finger on a stove top. This voluntary contraction begins with a thought process. A signal from your brain tells your muscles to contract or relax. Quickly contract and relax the muscles in your fingers a few times. Think about how quickly these signals must travel throughout your body to make this happen. 2. Smooth muscle is composed of involuntary muscles found within the walls of organs and structures such as the esophagus, stomach, intestines, and blood vessels. These muscles push materials like food or blood through organs. Unlike skeletal muscle, smooth muscle can never be under your control. 3. Cardiac muscle is also an involuntary muscle, found only in the heart. The cardiac muscle fibers all contract together, generating enough force to push blood throughout the body. What would happen if this muscle was under conscious or voluntary control? There are three types of muscles in the body: cardiac, skeletal, and smooth. "
what muscle pushes food through your intestines?,(A) skeletal muscle (B) smooth muscle (C) cardiac muscle (D) intestinal muscle,B,"The mouth is the first organ that food enters. But digestion may start even before you put the first bite of food into your mouth. Just seeing or smelling food can cause the release of saliva and digestive enzymes in your mouth. This diagram shows how muscles push food through the digestive system. Muscle contractions travel through the system in waves, pushing the food ahead of them. This is called peristalsis. Once you start eating, saliva wets the food, which makes it easier to break up and swallow. Digestive enzymes, including the enzyme amylase, start breaking down starches into sugars. Your tongue helps mix the food with the saliva and enzymes. Your teeth also help digest food. Your front teeth are sharp. They cut and tear food when you bite into it. Your back teeth are broad and flat. They grind food into smaller pieces when you chew. Chewing is part of mechanical digestion. Your tongue pushes the food to the back of your mouth so you can swallow it. When you swallow, the lump of chewed food passes down your throat to your esophagus. The esophagus is a narrow tube that carries food from the throat to the stomach. Food moves through the esophagus because of peristalsis. At the lower end of the esophagus, a circular muscle controls the opening to the stomach. The muscle relaxes to let food pass into the stomach. Then the muscle contracts again to prevent food from passing back into the esophagus. Some people think that gravity moves food through the esophagus. If that were true, food would move through the esophagus only when you are sitting or standing upright. In fact, because of peristalsis, food can move through the esophagus no matter what position you are ineven upside down! Just dont try to swallow food when you are upside downyou could choke! The stomach is a sac-like organ at the end of the esophagus. It has thick muscular walls. The muscles contract and relax. This moves the food around and helps break it into smaller pieces. Mixing the food around with the enzyme pepsin and other chemicals helps digest proteins. Water, salt, and simple sugars can be absorbed into the blood from the stomach. Most other substances are broken down further in the small intestine before they are absorbed. The stomach stores food until the small intestine is ready to receive it. A circular muscle controls the opening between the stomach and small intestine. When the small intestine is empty, the muscle relaxes. This lets food pass from the stomach into the small intestine. "
what muscle is found only in one place in the body?,(A) skeletal muscle (B) smooth muscle (C) cardiac muscle (D) brain muscle,C,"There are three different types of muscle tissue in the human body: cardiac, smooth, and skeletal muscle tissues. All three types consist mainly of muscle fibers, but the fibers have different arrangements. You can see how each type of muscle tissue looks in Figure 16.17. Cardiac muscle is found only in the walls of the heart. It is striated, or striped, because its muscle fibers are arranged in bundles. Contractions of cardiac muscle are involuntary. This means that they are not under conscious control. When cardiac muscle contracts, the heart beats and pumps blood. Smooth muscle is found in the walls of other internal organs such as the stomach. It isnt striated because its muscle fibers are arranged in sheets rather than bundles. Contractions of smooth muscle are involuntary. When smooth muscles in the stomach contract, they squeeze food inside the stomach. This helps break the food into smaller pieces. Skeletal muscle is attached to the bones of the skeleton. It is striated like cardiac muscle because its muscle fibers are arranged in bundles. Contractions of skeletal muscle are voluntary. This means that they are under conscious control. Whether you are doing pushups or pushing a pencil, you are using skeletal muscles. Skeletal muscles are the most common type of muscles in the body. You can read more about them below. "
where is smooth muscle located?,(A) brain (B) heart (C) and pancreas (D) b esophagus (E) stomach (F) intestines (G) and blood vessels (H) c kidney (I) liver (J) and spleen (K) d all of the above are correct,B,"Smooth muscles and cardiac muscles are not attached to bone. Recall that these types of muscles are under involuntary control. Smooth muscle is responsible for the contractility of hollow organs, such as blood vessels, the gastrointestinal tract, the bladder, or the uterus. Like skeletal muscles, smooth muscle fibers do contract together, causing the muscle to shorten. Smooth muscles have numerous functions, including the following. The smooth muscle in the uterus helps a woman to push out her baby. In the bladder, smooth muscle helps to push out urine. Smooth muscles move food through the digestive tract. In arteries, smooth muscle movements maintain the arteries diameter. Smooth muscle regulates air flow in lungs. Smooth muscle in the lungs helps the airways to expand and contract as necessary. Smooth muscles in arteries and veins are largely responsible for regulation of blood pressure. Cardiac muscle also contracts and gets shorter. This muscle is found only in the heart. The sudden burst of contraction forces blood throughout your body. When the cardiac muscle relaxes, the heart fills with blood. This rhythmic contraction must continue for your whole life, luckily the heart muscle never gets tired. If your heart beats 75 times a minute, how many times does it beat in an hour? A day? A year? 85 years? "
what are the two main proteins in muscle cells?,(A) actin and myosin (B) keratin and chitin (C) contractin and relaxin (D) collagen and chitin,A,"To understand how a muscle contracts, you need to dive deeper into the structure of muscle fibers. You can see in Figure 16.16 that a muscle fiber is full of myofibrils. Each myofibril is made up of two types of proteins, called actin and myosin. These proteins form thread-like filaments. The myosin filaments use energy from ATP to pull on the actin filaments. This causes the actin filaments to slide over the myosin filaments and shorten a section of the myofibril. You can see a simple animation of the process at this link: http://commons.wikimedia.org/wiki/File:Actin_Myosin.gif The sliding-and-shortening process occurs all along many myofibrils and in many muscle fibers. It causes the muscle fibers to shorten and the muscle to contract. "
water is an unlimited resource.,(A) true (B) false,B,"Most Americans have plenty of fresh, clean water. But many people around the world do not. In fact, water scarcity is the worlds most serious resource problem. How can that be? Water is almost everywhere. More than 70 percent of Earths surface is covered by water. "
many people do not have access to fresh unpolluted water.,(A) true (B) false,A,"Many people in the world have no choice but to drink from the same polluted river where sewage is dumped. One- fifth of all people in the world, more than 1.1 billion people, do not have access to safe water for drinking, personal cleanliness, and domestic use. Unsafe drinking water carries many pathogens, or disease-causing biological agents such as infectious bacteria and parasites. Toxic chemicals and radiological hazards in water can also cause diseases. "
when is water considered polluted?,(A) when it does nor support a use for animals or plants (B) when it does not support a human use (C) when it is not safe to drink (D) all of the above,D,"While to many people clean water may seem limitless and everywhere, to many others this is not so. Water pollution is a serious issue facing hundreds of millions of people world-wide, having harmful effects on the lives of those people. Water is not in unlimited supply and cannot just be made fresh when it is wanted. Water is actually a limited resource, and for many people, fresh, unpolluted water is hard to find. A limited resource is one that we use faster than we can remake it. It is a resource that can be used up. Water pollution happens when contaminants enter water bodies. Contaminants are any substances that harm the health of the environment or humans. Most contaminants enter the water because of humans. Surface water (river or lake) can be exposed to and contaminated by acid rain, storm water runoff, pesticide runoff, and industrial waste. This water is cleaned somewhat by exposure to sunlight, aeration, and microorganisms in the water. Groundwater (private wells and some public water supplies) generally takes longer to become contaminated, but the natural clean- ing process also may take much longer. Groundwater can be contaminated by disease-producing pathogens, careless disposal of hazardous household chemical-containing products, agricultural chemicals, and leaking underground storage tanks. Water pollution can cause harmful effects to ecology and human health. Shown is the pollution in Jakarta, Indonesia. Natural events, like storms, volcanic eruptions and earthquakes can cause major changes in water quality. But human-caused contaminants have a much greater impact on the quality of the water supply. Water is considered polluted either when it does not support a human use, like clean drinking water, or a use for other animals and plants. The overgrowth of algae, known as an algal bloom, can result from the runoff of fertilizer into bodies of water. This excess of nutrients allows the algae to grow beyond control, bring harm to the rest of the ecosystem. The main sources of water pollution can be grouped into two categories: Point source pollution results from the contaminants that enter a waterway or water body through a single site. Examples of this include untreated sewage, wastewater from a sewage treatment plant, and leaking underground tanks. Nonpoint source pollution is contamination that does not come from a single point source. Instead, it happens when there is a buildup of small amounts of contaminants that collect from a large area. Examples of this include fertilizer runoff from many farms flowing into groundwater or streams. "
what is a potential contaminant of groundwater.,(A) agricultural chemicals (B) hazardous household products (C) disease-producing pathogens (D) all of the above,D,"Groundwater pollutants are the same as surface water pollutants: municipal, agricultural, and industrial. Ground- water is more susceptible to some sources of pollution. For example, irrigation water infiltrates into the ground, bringing with it the pesticides, fertilizers, and herbicides that were sprayed on the fields. Water that seeps through landfills also carries toxins into the ground. Toxic substances and things like gasoline are kept in underground storage tanks; more than 100,000 of the tanks are currently leaking and many more may develop leaks. "
which of the following is an example of point source pollution?,(A) acid rain (B) untreated sewage (C) fertilizer runoff (D) pathogen contamination,B,"An example of point-source pollution is the release of pollution into a body of water through a pipe from a factory or sewage treatment plant. Waste water from a factory might contain dangerous chemicals such as strong acids, mercury, or lead. Water from a sewage treatment plant might contain untreated or partially treated sewage. Such pollution can make water dangerous for drinking or other uses. You can learn more about the problem of sewage contaminating the water in U.S. coastal communities by watching this video:  MEDIA Click image to the left or use the URL below. URL:  In poor nations, many people have no choice but to drink water from polluted sources. Drinking sewage-contaminated water causes waterborne diseases, due to pathogens such as protozoa, viruses, or bacteria. Most waterborne diseases cause diarrhea. "
which of the following is an example of nonpoint source pollution?,(A) underground storage tanks (B) untreated sewage (C) fertilizer runoff (D) wastewater,C,"Pollution that enters water at just one point is called point source pollution. For example, chemicals from a factory might empty into a stream through a pipe or set of pipes (see Figure 21.9). Pollution that enters in many places is called non-point source pollution. This means that the pollution is from multiple sources. With non-point source pollution, runoff may carry the pollution into a body of water. Which type of pollution do you think is harder to control? "
what is the primary cause of an algal bloom?,(A) runoff of fertilizer into bodies of water (B) leaking underground storage tanks (C) acid rain (D) pesticide runoff,A,"When fertilizer ends up in bodies of water, the added nutrients cause excessive growth of algae. This is called an algal bloom. You can see one in Figure 25.5. The algae out-compete other water organisms. They may make the water unfit for human consumption or recreation. "
there are five main tastes that humans can perceive.,(A) true (B) false,A,"Your sense of taste is controlled by sensory neurons, or nerve cells, on your tongue that sense the chemicals in food. The neurons are grouped in bundles within taste buds. Each taste bud actually has a pore that opens out to the surface of the tongue enabling molecules and ions taken into the mouth to reach the receptor cells inside. There are five different types of taste neurons on the tongue. Each type detects a different taste. The tastes are: 1. Sweet, which is produced by the presence of sugars, such as the common table sugar sucrose, and a few other substances. 2. Salty, which is produced primarily by the presence of sodium ions. Common salt is sodium chloride, NaCl. The use of salt can donate the sodium ion producing this taste. 3. Sour, which is the taste that detects acidity. The most common food group that contains naturally sour foods is fruit, such as lemon, grape, orange, and sometimes melon. Children show a greater enjoyment of sour flavors than adults, and sour candy such as Lemon Drops, Shock Tarts and sour versions of Skittles and Starburst, is popular. Many of these candies contain citric acid. 4. Bitter is an unpleasant, sharp, or disagreeable taste. Common bitter foods and beverages include coffee, unsweetened cocoa, beer (due to hops), olives, and citrus peel. 5. Umami, which is a meaty or savory taste. This taste can be found in fish, shellfish, cured meats, mushrooms, cheese, tomatoes, grains, and beans. A single taste bud contains 50100 taste cells representing all 5 taste sensations. A stimulated taste receptor cell triggers action potentials in a nearby sensory neuron, which send messages to the brain about the taste. The brain then decides what tastes you are sensing. "
you are able to sense many different flavors because of your sense of smell.,(A) true (B) false,A,"Your sense of smell also involves sensory neurons that sense chemicals. The neurons are found in the nose, and they detect chemicals in the air. Unlike taste neurons, which can detect only five different tastes, the sensory neurons in the nose can detect thousands of different odors. Have you ever noticed that you lose your sense of taste when your nose is stuffed up? Thats because your sense of smell greatly affects your ability to taste food. As you eat, molecules of food chemicals enter your nose (actually your nasal cavity). You experience the taste and smell at the same time. Being able to smell as well as taste food greatly increases the number of different flavors you are able to sense. For example, you can use your sense of taste alone to learn that a food is sweet, but you have to also use your sense of smell to learn that the food tastes like strawberry cheesecake. Specific scents are often associated with our memories of places and events. Thats because scents are more novel or specific than shapes or other things you might see. So an odor similar to that of your grandmothers kitchen or pantry might be more quickly associated with your memories of that place than a similar sight, which might be more generalized. "
"if you hold your nose and start chewing a watermelon jellybean, what will it taste like?",(A) watermelon (B) sweet (C) sour (D) all of the above,B,"Does the sight or smell of your favorite food make your mouth water? When this happens, you are getting ready for digestion. "
which taste will be associated with citrus fruits?,(A) sweet (B) sour (C) salty (D) bitter,B,"Your sense of taste is controlled by sensory neurons, or nerve cells, on your tongue that sense the chemicals in food. The neurons are grouped in bundles within taste buds. Each taste bud actually has a pore that opens out to the surface of the tongue enabling molecules and ions taken into the mouth to reach the receptor cells inside. There are five different types of taste neurons on the tongue. Each type detects a different taste. The tastes are: 1. Sweet, which is produced by the presence of sugars, such as the common table sugar sucrose, and a few other substances. 2. Salty, which is produced primarily by the presence of sodium ions. Common salt is sodium chloride, NaCl. The use of salt can donate the sodium ion producing this taste. 3. Sour, which is the taste that detects acidity. The most common food group that contains naturally sour foods is fruit, such as lemon, grape, orange, and sometimes melon. Children show a greater enjoyment of sour flavors than adults, and sour candy such as Lemon Drops, Shock Tarts and sour versions of Skittles and Starburst, is popular. Many of these candies contain citric acid. 4. Bitter is an unpleasant, sharp, or disagreeable taste. Common bitter foods and beverages include coffee, unsweetened cocoa, beer (due to hops), olives, and citrus peel. 5. Umami, which is a meaty or savory taste. This taste can be found in fish, shellfish, cured meats, mushrooms, cheese, tomatoes, grains, and beans. A single taste bud contains 50100 taste cells representing all 5 taste sensations. A stimulated taste receptor cell triggers action potentials in a nearby sensory neuron, which send messages to the brain about the taste. The brain then decides what tastes you are sensing. "
which food will have an umami taste?,(A) candy (B) fish (C) oranges (D) beer,B,"Your sense of taste is controlled by sensory neurons, or nerve cells, on your tongue that sense the chemicals in food. The neurons are grouped in bundles within taste buds. Each taste bud actually has a pore that opens out to the surface of the tongue enabling molecules and ions taken into the mouth to reach the receptor cells inside. There are five different types of taste neurons on the tongue. Each type detects a different taste. The tastes are: 1. Sweet, which is produced by the presence of sugars, such as the common table sugar sucrose, and a few other substances. 2. Salty, which is produced primarily by the presence of sodium ions. Common salt is sodium chloride, NaCl. The use of salt can donate the sodium ion producing this taste. 3. Sour, which is the taste that detects acidity. The most common food group that contains naturally sour foods is fruit, such as lemon, grape, orange, and sometimes melon. Children show a greater enjoyment of sour flavors than adults, and sour candy such as Lemon Drops, Shock Tarts and sour versions of Skittles and Starburst, is popular. Many of these candies contain citric acid. 4. Bitter is an unpleasant, sharp, or disagreeable taste. Common bitter foods and beverages include coffee, unsweetened cocoa, beer (due to hops), olives, and citrus peel. 5. Umami, which is a meaty or savory taste. This taste can be found in fish, shellfish, cured meats, mushrooms, cheese, tomatoes, grains, and beans. A single taste bud contains 50100 taste cells representing all 5 taste sensations. A stimulated taste receptor cell triggers action potentials in a nearby sensory neuron, which send messages to the brain about the taste. The brain then decides what tastes you are sensing. "
regular black coffee without any sweetener would taste __________ to many people.,(A) sweet (B) salty (C) sour (D) bitter,D,"All bases share certain properties, including a bitter taste. (Never taste an unknown substance to see whether it is a base!) Did you ever taste unsweetened cocoa powder? It tastes bitter because it is a base. Bases also feel slippery. Think about how slippery soap feels. Soap is also a base. Like acids, bases conduct electricity because they consist of charged particles in solution. "
a food with high amounts of sucrose and nacl would be,(A) sweet and sour (B) sweet and salty (C) salty and bitter (D) salty and sour,B,"Starch is a large, complex carbohydrate made of thousands of glucose units (monomers) joined together. Starches are found in foods such as vegetables and grains. Starches are broken down by the body into sugars that provide energy. Breads and pasta are good sources of complex carbohydrates. Fiber is another type of large, complex carbohydrate that is partly indigestible. Unlike sugars and starches, fiber does not provide energy. However, it has other important roles in the body. For example, fiber is important for maintaining the health of your gastrointestinal tract. Eating foods high in fiber also helps fill you up without providing too many calories. Most fruits and vegetables are high in fiber. Some examples are pictured below ( Figure 1.2). "
carbon is necessary for living organisms to make organic compounds.,(A) true (B) false,A,"Carbon is a very important element to living things. As the second most common element in the human body, we know that human life without carbon would not be possible. Protein, carbohydrates, and fats are all part of the body and all contain carbon. When your body breaks down food to produce energy, you break down protein, carbohydrates, and fat, and you breathe out carbon dioxide. Carbon occurs in many forms on Earth. The element moves through organisms and then returns to the environment. When all this happens in balance, the ecosystem remains in balance too. "
people are able to make the carbon they need for their cells.,(A) true (B) false,B,Producers such as plants or algae use carbon dioxide in the air to make food. The organisms combine carbon dioxide with water to make sugar. They store the sugar as starch. Both sugar and starch are carbohydrates. Consumers get carbon when they eat producers or other consumers. Carbon doesnt stop there. Living things get energy from food in a process called respiration. This releases carbon dioxide back into the atmosphere. The cycle then repeats. 
where does the carbon dioxide we exhale come from?,(A) Carbon dioxide is a product of cellular respiration (B) Carbon dioxide is obtained from the atmosphere (C) Carbon dioxide is obtained from the food we eat (D) all of the above,A,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
burning of organic matter releases carbon dioxide into the atmosphere. this process is known as,(A) respiration (B) consumption (C) combustion (D) decomposition,C,"Millions of years ago, there were so many dead plants and animals that they could not completely decompose before they were buried. They were covered over by soil or sand, tar or ice. These dead plants and animals are organic matter made out of cells full of carbon-containing organic compounds (carbohydrates, lipids, proteins and nucleic acids). What happened to all this carbon? When organic matter is under pressure for millions of years, it forms fossil fuels. Fossil fuels are coal, oil, and natural gas. When humans dig up and use fossil fuels, we have an impact on the carbon cycle ( Figure 1.2). This carbon is not recycled until it is used by humans. The burning of fossil fuels releases more carbon dioxide into the atmosphere than is used by photosynthesis. So, there is more carbon dioxide entering the atmosphere than is coming out of it. Carbon dioxide is known as a greenhouse gas, since it lets in light energy but does not let heat escape, much like the panes of a greenhouse. The increase of greenhouse gasses in the atmosphere is contributing to a global rise in Earths temperature, known as global warming or global climate change. "
which depicts cellular respiration?,(A) uses glucose and carbon dioxide and makes oxygen and water (B) uses glucose and oxygen and makes carbon dioxide and water (C) uses oxygen and carbon dioxide and makes glucose and water (D) uses water and carbon dioxide and makes glucose and oxygen,B,"The overall chemical reaction for cellular respiration is one molecule of glucose (C6 H12 O6 ) and six molecules of oxygen (O2 ) yields six molecules of carbon dioxide (CO2 ) and six molecules of water (H2 O). Using chemical symbols the equation is represented as follows: C6 H12 O6 + 6O2  6CO2 + 6H2 O ATP is generated during the process. Though this equation may not seem that complicated, cellular respiration is a series of chemical reactions divided into three stages: glycolysis, the Krebs cycle, and the electron transport chain. "
"when organisms die, what process returns their carbon back into the atmosphere?",(A) respiration (B) erosion (C) combustion (D) decomposition,D,"Major exchange pools of carbon include organisms and the atmosphere. Carbon cycles more quickly between these components of the carbon cycle. Photosynthesis by plants and other producers removes carbon dioxide from the atmosphere to make organic compounds for living things. Cellular respiration by living things releases carbon into the atmosphere or ocean as carbon dioxide. Decomposition of dead organisms and organic wastes releases carbon back to the atmosphere, soil, or ocean. "
which of the following are fossil fuels?,(A) coal (B) oil (C) and natural gas (D) b coal (E) tar and gasoline (F) c tar (G) oil and gas (H) d coal (I) oil and natural wood,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
nitrogen is important for creating both proteins and carbohydrates.,(A) true (B) false,B,"Living things also need nitrogen. Nitrogen is a key element in proteins. Like carbon, nitrogen cycles through ecosystems. You can see the nitrogen cycle in Figure 18.13. "
most plants and animals cannot use the nitrogen in nitrogen gas.,(A) true (B) false,A,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
the initial step of producing a nitrogen containing compound from nitrogen in the soil is,(A) assimilation (B) ammonification (C) nitrification (D) denitrification,B,"Although nitrogen is the most abundant gas in the atmosphere, it is not in a form that plants can use. To be useful, nitrogen must be fixed, or converted into a more useful form. Although some nitrogen is fixed by lightning or blue-green algae, much is modified by bacteria in the soil. These bacteria combine the nitrogen with oxygen or hydrogen to create nitrates or ammonia (Figure 1.2). (a) Nucleic acids contain nitrogen (b) Chlorophyll molecules contain nitrogen "
the final step of releasing nitrogen gas back into the atmosphere is,(A) assimilation (B) ammonification (C) nitrification (D) denitrification,C,"Turning nitrate back into nitrogen gas, the process of denitrification, happens through the work of denitrifying bacteria. These bacteria often live in swamps and lakes. They take in the nitrate and release it back to the atmosphere as nitrogen gas. Just like the carbon cycle, human activities impact the nitrogen cycle. These human activities include the burning of fossil fuels, which release nitrogen oxide gasses into the atmosphere. Releasing nitrogen oxide back into the atmosphere leads to problems like acid rain. "
nitrogen gas is two nitrogen atoms held together by,(A) a very strong single bond (B) a very strong double bond (C) a very strong triple bond (D) a nitrogen bond,C,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
nitrogen enters the roots of plants in a process called,(A) assimilation (B) ammonification (C) nitrogen fixation (D) nitrification,A,"Like water and carbon, nitrogen is also repeatedly recycled through the biosphere. This process is called the nitrogen cycle. Nitrogen is one of the most common elements in living organisms. It is important for creating both proteins and nucleic acids, like DNA. The air that we breathe is mostly nitrogen gas (N2 ), but, unfortunately, animals and plants cannot use the nitrogen when it is a gas. In fact, plants often die from a lack of nitrogen even through they are surrounded by plenty of nitrogen gas. Nitrogen gas (N2 ) has two nitrogen atoms connected by a very strong triple bond. Most plants and animals cannot use the nitrogen in nitrogen gas because they cannot break that triple bond. In order for plants to make use of nitrogen, it must be transformed into molecules they can use. This can be accomplished several different ways ( Figure 1.1). Lightning: When lightening strikes, nitrogen gas is transformed into nitrate (NO3  ) that plants can use. Nitrogen fixation: Special nitrogen-fixing bacteria can also transform nitrogen gas into useful forms. These bacteria live in the roots of plants in the pea family. They turn the nitrogen gas into ammonium (NH4 + ) (a process called ammonification). In water environments, bacteria in the water can also fix nitrogen gas into ammonium. Ammonium can be used by aquatic plants as a source of nitrogen. Nitrogen also is released to the environment by decaying organisms or decaying wastes. These wastes release nitrogen in the form of ammonium. Ammonium in the soil can be turned into nitrate by a two-step process completed by two different types of bacteria. In the form of nitrate, nitrogen can be used by plants through the process of assimilation. It is then passed along to animals when they eat the plants. "
what bacteria live in the root nodules of legumes?,(A) denitrifying bacteria (B) nitrifying bacteria (C) nitrogen-fixing bacteria (D) all of the above,C,"Some bacteria depend on other organisms for survival. For example, some bacteria live in the roots of legumes, such as pea plants ( Figure 1.1). The bacteria turn nitrogen-containing molecules into nitrogen that the plant can use. Meanwhile, the root provides nutrients to the bacteria. In this relationship, both the bacteria and the plant benefit, so it is known as a mutualism. Other mutualistic bacteria include gut microbes. These are bacteria that live in the intestines of animals. They are usually beneficial bacteria, needed by the host organism. These microbes obviously dont kill their host, as that would kill the bacteria as well. "
the water cycle recycles water through both the living and non-living parts of an ecosystem.,(A) true (B) false,A,"Water is recycled through the water cycle. The water cycle is the movement of water through the oceans, atmo- sphere, land, and living things. The water cycle is powered by energy from the Sun. Figure 13.3 diagrams the water cycle. "
the water cycle always starts with water evaporating from the ocean or lakes.,(A) true (B) false,B,"The oceans are an essential part of Earths water cycle. Since they cover so much of the planet, most evaporation comes from oceans and most precipitation falls on oceans. "
what is the process in which water evaporates from leaves?,(A) condensation (B) precipitation (C) evaporation (D) transpiration,D,"Water changes to a gas by three different processes called evaporation, sublimation, and transpiration. Evaporation takes place when water on Earths surface changes to water vapor. The sun heats the water and gives water molecules enough energy to escape into the atmosphere. Most evaporation occurs from the surface of the ocean. Sublimation takes place when snow and ice on Earths surface change directly to water vapor without first melting to form liquid water. This also happens because of heat from the sun. Transpiration takes place when plants release water vapor through pores in their leaves called stomata. "
what process allows water to return to the earths surface?,(A) condensation (B) precipitation (C) evaporation (D) transpiration,B,"The movement of water around Earths surface is the hydrological (water) cycle (Figure 1.1). Water inhabits reservoirs within the cycle, such as ponds, oceans, or the atmosphere. The molecules move between these reservoirs by certain processes, including condensation and precipitation. There are only so many water molecules and these molecules cycle around. If climate cools and glaciers and ice caps grow, there is less water for the oceans and sea level will fall. The reverse can also happen. The following section looks at the reservoirs and the processes that move water between them. "
which of the following is in the correct order?,(A) precipitation ® runoff ® streams/rivers ® oceans ® evaporation (B) precipitation ® runoff ® groundwater ® oceans ® evaporation (C) precipitation ® runoff ® aquifer ® oceans ® evaporation (D) transpiration ® runoff ® streams/rivers ® aquifers ® evaporation,A,"The basic building blocks of the human body are cells. Human cells are organized into tissues, tissues are organized into organs, and organs are organized into organ systems. "
evaporation produces,(A) precipitation (B) rain or snow (C) water vapor (D) condensation,C,"Evaporation explains why clothes dry on a clothesline. Evaporation is the process in which a liquid changes to a gas without becoming hot enough to boil. It occurs when individual liquid particles at the exposed surface of the liquid absorb just enough energy to overcome the force of attraction with other liquid particles. If the surface particles are moving in the right direction, they will pull away from the liquid and move into the air. This is illustrated in the Figure 1.1. "
"rain, snow, hail, and sleet are examples of",(A) precipitation (B) condensation (C) evaporation (D) bad weather,A,"The most common precipitation comes from clouds. Rain or snow droplets grow as they ride air currents in a cloud and collect other droplets (Figure 1.2). They fall when they become heavy enough to escape from the rising air currents that hold them up in the cloud. One million cloud droplets will combine to make only one rain drop! If temperatures are cold, the droplet will hit the ground as snow. (a) Dew on a flower. (b) Hoar frost. (a) Rain falls from clouds when the temperature is fairly warm. (b) Snow storm in Helsinki, Finland. Other less common types of precipitation are sleet (Figure 1.3). Sleet is rain that becomes ice as it hits a layer of freezing air near the ground. If a frigid raindrop freezes on the frigid ground, it forms glaze. Hail forms in cumulonimbus clouds with strong updrafts. An ice particle travels until it finally becomes too heavy and it drops. (a) Sleet. (b) Glaze. (c) Hail. This large hail stone is about 6 cm (2.5 inches) in diameter. Click image to the left or use the URL below. URL: "
life on earth began about 3.5 to 4 million years ago.,(A) true (B) false,B,"Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria. These first life forms were, of course, very basic, and this then allowed for the evolution of more complex life forms. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion. This sudden burst of evolution may have been caused by some environmental changes that made the Earths environment more suitable for a wider variety of life forms. Plants and fungi did not appear until roughly 500 million years ago. They were soon followed by arthropods (insects and spiders). Next came the amphibians about 300 million years ago, followed by mammals around 200 million years ago and birds around 100 million years ago. Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotessmall, relatively simple single-celled organisms. As it is difficult to identify, observe and study such small forms of life, most of these organisms remain unknown to scientists. Advancing technologies, however, do allow for the identification and study of such organisms. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist. The basic timeline of a 4.6 billion-year-old Earth includes the following: About 3.5 - 3.8 billion years of simple cells (prokaryotes). 3 billion years of photosynthesis. 2 billion years of complex cells (eukaryotes). 1 billion years of multicellular life. 600 million years of simple animals. 570 million years of arthropods (ancestors of insects, arachnids and crustaceans). 550 million years of complex animals. 500 million years of fish and proto-amphibians. 475 million years of land plants. 400 million years of insects and seeds. 360 million years of amphibians. 300 million years of reptiles. 200 million years of mammals. 150 million years of birds. 130 million years of flowers. 65 million years since the non-avian dinosaurs died out. 2.5 million years since the appearance of Homo. 200,000 years since the appearance of modern humans. 25,000 years since Neanderthals died out. "
"most life is made of small, relatively simple single-celled organisms.",(A) true (B) false,A,"Cells are the basic building blocks of life. They are like tiny factories where virtually all life processes take place. Some living things, like the bacteria in Figure 2.1, consist of just one cell. They are called single-celled organisms. You can see other single-celled organisms in Figure 2.2. Some living things are composed of a few to many trillions of cells. They are called multicellular organisms. Your body is composed of trillions of cells. Regardless of the type of organism, all living cells share certain basic structures. For example, all cells are enclosed by a membrane. The cell membrane separates the cell from its environment. It also controls what enters or leaves the cell. "
when did modern humans first appear?,(A) 20 (B) 000 (C) 000 years ago (D) b 2 (E) 000 (F) 000 years ago (G) c 200 (H) 000 years ago (I) d 20 (J) 000 years ago,C,"Animals of the genus Ardipithecus, living roughly 4 to 6 million years ago, had brains roughly the size of a female chimp. Although they lived in trees, they were bipedal. Standing on two feet allows an organism to see and also to use its hands and arms for hunting. By the time of Australopithecus afarensis, between 3.9 and 2.9 million years ago, these human ancestors were completely bipedal and their brains were growing rapidly (Figure 1.1). Australopithecus afarensis is a human ancestor that lived about 3 million years ago. The genus Homo appeared about 2.5 million years ago. Humans developed the first stone tools. Homo erectus evolved in Africa about 1.8 million years ago. Fossils of these animals show a much more human-like body structure, which allowed them to travel long distances to hunt. Cultures begin and evolve. Homo sapiens, our species, originated about 200,000 years ago in Africa. Evidence of a spiritual life appears about 32,000 years ago with stone figurines that probably have religious significance (Figure 1.2). The ice ages allowed humans to migrate. During the ice ages, water was frozen in glaciers and so land bridges such as the Bering Strait allowed humans to walk from the old world to the new world. DNA evidence suggests that the humans who migrated out of Africa interbred with Neanderthal since these people contain some Neanderthal DNA. Click image to the left or use the URL below. URL:  Stone figurines likely indicate a spiritual life. "
what were the first life forms?,(A) single-celled organisms similar to protists (B) single-cell organisms similar to bacteria (C) simple organisms similar to small water insects (D) simple organisms similar to small flies,B,"Life on Earth began about 3.5 to 4 billion years ago. The first life forms were single-celled organisms similar to bacteria. These first life forms were, of course, very basic, and this then allowed for the evolution of more complex life forms. The first multicellular organisms did not appear until about 610 million years ago. Many different types of organisms evolved during the next ten million years, in an event called the Cambrian Explosion. This sudden burst of evolution may have been caused by some environmental changes that made the Earths environment more suitable for a wider variety of life forms. Plants and fungi did not appear until roughly 500 million years ago. They were soon followed by arthropods (insects and spiders). Next came the amphibians about 300 million years ago, followed by mammals around 200 million years ago and birds around 100 million years ago. Even though large life forms have been very successful on Earth, most of the life forms on Earth today are still prokaryotessmall, relatively simple single-celled organisms. As it is difficult to identify, observe and study such small forms of life, most of these organisms remain unknown to scientists. Advancing technologies, however, do allow for the identification and study of such organisms. Fossils indicate that many organisms that lived long ago are extinct. Extinction of species is common; in fact, it is estimated that 99% of the species that have ever lived on Earth no longer exist. The basic timeline of a 4.6 billion-year-old Earth includes the following: About 3.5 - 3.8 billion years of simple cells (prokaryotes). 3 billion years of photosynthesis. 2 billion years of complex cells (eukaryotes). 1 billion years of multicellular life. 600 million years of simple animals. 570 million years of arthropods (ancestors of insects, arachnids and crustaceans). 550 million years of complex animals. 500 million years of fish and proto-amphibians. 475 million years of land plants. 400 million years of insects and seeds. 360 million years of amphibians. 300 million years of reptiles. 200 million years of mammals. 150 million years of birds. 130 million years of flowers. 65 million years since the non-avian dinosaurs died out. 2.5 million years since the appearance of Homo. 200,000 years since the appearance of modern humans. 25,000 years since Neanderthals died out. "
the geologic time scale is used to describe events such as,(A) mass extinctions and signs of life (B) earthquakes and volcanic eruptions (C) major erosion events and meteorites impacting Earth (D) All of the above are shown on the geologic time scale,D,Geologists and other Earth scientists use geologic time scales to describe when events happened in the history of Earth. The time scales can be used to show when both geologic events and events affecting plant and animal life occurred. The geologic time scale pictured below ( Figure 1.1) illustrates the timing of events like: Earthquakes. Volcanic eruptions. Major erosion. Meteorites hitting Earth. The first signs of life forms. Mass extinctions. 
evidence of an ancient earth includes,(A) fossils found in rocks (B) fossils of old life found high up in the mountains (C) fossils of ancient sea life on dry land far from oceans (D) fossils of ancient fish found in the oceans,C,"How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists, and naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: Fossils of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans. The many layers of rock. When people realized that rock layers represent the order in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth. Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earths surface. This supported the idea of an older Earth. The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years. "
the oldest the earth can be is,(A) 4 (B) 400 (C) 000 (D) 000 years (E) b 44 (F) 570 (G) 000 (H) 000 years (I) c 457 (J) 000 (K) 000 (L) 000 years (M) d 4 (N) 570 (O) 000 (P) 000 years,D,"How old is Earth? How was it formed? How did life begin on Earth? These questions have fascinated scientists for centuries. During the 1800s, geologists, paleontologists, and naturalists found several forms of physical evidence that confirmed that Earth is very old. The evidence includes: Fossils of ancient sea life on dry land far from oceans. This supported the idea that the Earth changed over time and that some dry land today was once covered by oceans. The many layers of rock. When people realized that rock layers represent the order in which rocks and fossils appeared, they were able to trace the history of Earth and life on Earth. Indications that volcanic eruptions, earthquakes, and erosion that happened long ago shaped much of the Earths surface. This supported the idea of an older Earth. The Earth is at least as old as its oldest rocks. The oldest rock minerals found on Earth so far are crystals that are at least 4.404 billion years old. These tiny crystals were found in Australia. Likewise, Earth cannot be older than the solar system. The oldest possible age of Earth is 4.57 billion years old, the age of the solar system. Therefore, the age of Earth is between 4.4 and 4.57 billion years. "
all reactions due to touch are controlled by the brain.,(A) true (B) false,B,"When you look at the prickly cactus pictured below ( Figure 1.1), does the word ""ouch"" come to mind? Touching the cactus would be painful. Touch is the sense of pain, pressure, or temperature. Touch depends on sensory neurons, or nerve cells, in the skin. The skin on the palms of the hands, soles of the feet, and face has the most sensory neurons and is especially sensitive to touch. The tongue and lips are very sensitive to touch as well. Neurons that sense pain are also found inside the body in muscles, joints, and organs. If you have a stomach ache or pain from a sprained ankle, its because of these sensory neurons found inside of your body. The following example shows how messages about touch travel from sensory neurons to the brain, as well as how the brain responds to the messages. Suppose you wanted to test the temperature of the water in a lake before jumping in. You might stick one bare foot in the water. Neurons in the skin on your foot would sense the temperature of the water and send a message about it to your central nervous system. The frontal lobe of the cerebrum would process the information. It might decide that the water is really cold and send a message to your muscles to pull your foot out of the water. In some cases, messages about pain or temperature dont travel all the way to and from the brain. Instead, they travel only as far as the spinal cord, and the spinal cord responds to the messages by giving orders to the muscles. This allows you to respond to pain more quickly. When messages avoid the brain in this way, it forms a reflex arc, like the one shown below ( Figure 1.2). "
there are millions of touch receptors scattered throughout the body.,(A) true (B) false,A,"Our sense of touch is controlled by a huge network of nerve endings and touch receptors. This system is responsible for all the sensations we feel, including cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. There are four main types of receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. Mechanoreceptors perceive sensations such as pressure, vibrations, and texture. Your brain gets an enormous amount of information about the texture of objects through your fingertips because the ridges that make up your fingerprints are full of these sensitive receptors. Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears. Pain receptors, or nociceptor detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. There are over three million pain receptors throughout the body, found in skin, muscles, bones, blood vessels, and some organs. Proprioceptors detect the position of different parts of the body in relation to each other and the surrounding environment. These receptors are found in joints, tendons and muscles, and allow us to do fundamental things such as feeding or clothing ourselves. "
which receptors perceive sensations related to the temperature of objects?,(A) mechanoreceptors (B) thermoreceptors (C) nociceptors (D) proprioceptors,B,"Our sense of touch is controlled by a huge network of nerve endings and touch receptors. This system is responsible for all the sensations we feel, including cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. There are four main types of receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. Mechanoreceptors perceive sensations such as pressure, vibrations, and texture. Your brain gets an enormous amount of information about the texture of objects through your fingertips because the ridges that make up your fingerprints are full of these sensitive receptors. Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears. Pain receptors, or nociceptor detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. There are over three million pain receptors throughout the body, found in skin, muscles, bones, blood vessels, and some organs. Proprioceptors detect the position of different parts of the body in relation to each other and the surrounding environment. These receptors are found in joints, tendons and muscles, and allow us to do fundamental things such as feeding or clothing ourselves. "
which receptors allow us to do fundamental activities?,(A) mechanoreceptors (B) thermoreceptors (C) nociceptors (D) proprioceptors,D,"Our sense of touch is controlled by a huge network of nerve endings and touch receptors. This system is responsible for all the sensations we feel, including cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. There are four main types of receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. Mechanoreceptors perceive sensations such as pressure, vibrations, and texture. Your brain gets an enormous amount of information about the texture of objects through your fingertips because the ridges that make up your fingerprints are full of these sensitive receptors. Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears. Pain receptors, or nociceptor detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. There are over three million pain receptors throughout the body, found in skin, muscles, bones, blood vessels, and some organs. Proprioceptors detect the position of different parts of the body in relation to each other and the surrounding environment. These receptors are found in joints, tendons and muscles, and allow us to do fundamental things such as feeding or clothing ourselves. "
"which receptors perceive sensations such as pressure, vibrations, and texture?",(A) mechanoreceptors (B) thermoreceptors (C) nociceptors (D) proprioceptors,A,"Our sense of touch is controlled by a huge network of nerve endings and touch receptors. This system is responsible for all the sensations we feel, including cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. There are four main types of receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. Mechanoreceptors perceive sensations such as pressure, vibrations, and texture. Your brain gets an enormous amount of information about the texture of objects through your fingertips because the ridges that make up your fingerprints are full of these sensitive receptors. Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears. Pain receptors, or nociceptor detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. There are over three million pain receptors throughout the body, found in skin, muscles, bones, blood vessels, and some organs. Proprioceptors detect the position of different parts of the body in relation to each other and the surrounding environment. These receptors are found in joints, tendons and muscles, and allow us to do fundamental things such as feeding or clothing ourselves. "
the fingertips have the highest amount of,(A) mechanoreceptors (B) thermoreceptors (C) nociceptors (D) proprioceptors,A,Fingernails and toenails are made of specialized cells that grow out of the epidermis. They too are filled with keratin. The keratin makes them tough and hard. Their job is to protect the ends of the fingers and toes. They also make it easier to feel things with the sensitive fingertips by acting as a counterforce when things are handled. 
"which receptors are found in skin, muscles, bones, blood vessels, and some organs?",(A) mechanoreceptors (B) thermoreceptors (C) nociceptors (D) proprioceptors,C,"Our sense of touch is controlled by a huge network of nerve endings and touch receptors. This system is responsible for all the sensations we feel, including cold, hot, smooth, rough, pressure, tickle, itch, pain, vibrations, and more. There are four main types of receptors: mechanoreceptors, thermoreceptors, pain receptors, and proprioceptors. Mechanoreceptors perceive sensations such as pressure, vibrations, and texture. Your brain gets an enormous amount of information about the texture of objects through your fingertips because the ridges that make up your fingerprints are full of these sensitive receptors. Thermoreceptors perceive sensations related to the temperature of objects. There are two basic categories of thermoreceptors: hot receptors and cold receptors. The highest concentration of thermoreceptors can be found in the face and ears. Pain receptors, or nociceptor detect pain or stimuli that can or does cause damage to the skin and other tissues of the body. There are over three million pain receptors throughout the body, found in skin, muscles, bones, blood vessels, and some organs. Proprioceptors detect the position of different parts of the body in relation to each other and the surrounding environment. These receptors are found in joints, tendons and muscles, and allow us to do fundamental things such as feeding or clothing ourselves. "
transcription occurs in a ribosome in the nucleus.,(A) true (B) false,B,"Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as a template, nucleotides are joined together to make a complementary strand of mRNA. The mRNA contains bases that are complementary to the bases in the DNA strand. Translation is the second step in protein synthesis. It is shown in Figure 5.20. Translation takes place at a ribosome in the cytoplasm. During translation, the genetic code in mRNA is read to make a protein. Heres how it works: 1. 2. 3. 4. 5. The molecule of mRNA leaves the nucleus and moves to a ribosome. The ribosome consists of rRNA and proteins. It reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence. At the ribosome, the amino acids are joined together to form a chain of amino acids. The chain of amino acids keeps growing until a stop codon is reached. Then the chain is released from the ribosome. "
all genes in a cell are transcribed into mrna.,(A) true (B) false,B,"DNA is located in the nucleus. Proteins are made on ribosomes in the cytoplasm. Remember that information in a gene is converted into mRNA, which carries the information to the ribosome. In the nucleus, mRNA is created by using the DNA in a gene as a template. A template is a model provided for others to copy. The process of constructing an mRNA molecule from DNA is known as transcription ( Figure 1.1 and Figure of double stranded DNA. In transcription, only one strand of DNA is used as a template. First, the double helix of DNA unwinds and an enzyme, RNA Polymerase, builds the mRNA using the DNA as a template. The nucleotides follow basically the same base pairing rules as in DNA to form the correct sequence in the mRNA. This time, however, uracil (U) pairs with each adenine (A) in the DNA. For example, a DNA sequence ACGGGTAAGG will be transcribed into the mRNA sequence UGCCCAUUCC. In this manner, the information of the DNA is passed on to the mRNA. The mRNA will carry this code to the ribosomes to tell them how to make a protein. As not all genes are used in every cell, a gene must be ""turned on"" or expressed when the gene product is needed by the cell. Only the information in a gene that is being expressed is transcribed into an mRNA. Transcription is when RNA is created from a DNA template. Each gene (a) contains triplets of bases (b) that are transcribed into RNA (c). Every triplet in the DNA, or codon in the mRNA, encodes for a unique amino acid. Base-pairing ensures the accuracy of transcription. Notice how the helix must unwind for transcription to take place. The new mRNA is shown in green. "
"if a gene sequence is acgtttacaa, what will be the corresponding mrna sequence?",(A) TGCAAATGTT (B) UGCAAAUGUU (C) AGCUUUACAA (D) AGCUUUAGAA,B,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
what is one significant difference between transcription and dna replication?,(A) The DNA unwinds during transcription (B) In transcription (C) U pairs with A instead of T pairing with A (D) c The new DNA moves to the ribosome (E) d All of the above are significant differences,B,"Transcription is the first step in protein synthesis. It takes place in the nucleus. During transcription, a strand of DNA is copied to make a strand of mRNA. How does this happen? It occurs by the following steps, as shown in Figure 5.19. 1. An enzyme binds to the DNA. It signals the DNA to unwind. 2. After the DNA unwinds, the enzyme can read the bases in one of the DNA strands. 3. Using this strand of DNA as a template, nucleotides are joined together to make a complementary strand of mRNA. The mRNA contains bases that are complementary to the bases in the DNA strand. Translation is the second step in protein synthesis. It is shown in Figure 5.20. Translation takes place at a ribosome in the cytoplasm. During translation, the genetic code in mRNA is read to make a protein. Heres how it works: 1. 2. 3. 4. 5. The molecule of mRNA leaves the nucleus and moves to a ribosome. The ribosome consists of rRNA and proteins. It reads the sequence of codons in mRNA. Molecules of tRNA bring amino acids to the ribosome in the correct sequence. At the ribosome, the amino acids are joined together to form a chain of amino acids. The chain of amino acids keeps growing until a stop codon is reached. Then the chain is released from the ribosome. "
which of the following is incorrect?,(A) DNA does not leave the nucleus (B) DNA provides a template for transcription (C) All genes are transcribed in each cell (D) Uracil base pairs with adenine,C,"The following is an analysis of the statements above: 1. This is a fact made from observation. 2. The first part is from observations. The second is a fact drawn from the prior observations. The third is an opinion, since she might actually have allergies or the flu. Tests could be done to see what is causing her illness. 3. This is a fact. Many, many scientific experiments have shown that colds are caused by viruses. 4. While that sounds like a fact, the scientific evidence is mixed. One reputable study published in 2007 showed a decrease of 58%, but several other studies have shown no beneficial effect. 5. Bill Gates is the wealthiest man in the United States; thats a fact. But theres no evidence that hes also the smartest man, and chances are hes not. This is an opinion. 6. This sounds like a fact, but it is not. It is easy to test. Gather together a large number of subjects, each with a friend. Have the friends fill out a questionnaire describing the subject. Match the traits against the persons astrological sign to see if the astrological predictions fit. Are Leos actually more fiery, self assured, and charming? Tests like this have not supported the claims of astrologers, yet astrologers have not modified their opinions. 7. This is a fact. The Figure 1.2 shows the temperature anomaly since 1880. Theres no doubt that temperature has risen overall since 1880 and especially since the late 1970s. Global Average Annual Temperatures are Rising. This graph shows temperature anomaly relative to the 1951-1980 aver- age (the average is made to be 0). The green bars show uncertainty. "
which best describes a codon?,(A) A codon is a triplet of three bases in the gene sequence (B) A codon is a triplet of three bases in the mRNA that codes for a specific gene (C) A	codon	is	a	triplet	of	three	bases	in	the	mRNA	that	codes	for	a	specific (D) A	codon	is	a	triplet	of	three	bases	in	the	DNA	that	codes	for	a	specific	 amino	acid,C,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
which best defines an mrna molecule?,(A) A molecule that carries the instructions in the DNA to the ribosome (B) A molecule that carries the instructions in the RNA to the ribosome (C) A molecule that carries the instructions in the DNA to the nucleus (D) A molecule that carries the instructions in the mRNA to the gene,A,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
ribosomes are the organelles where proteins are made.,(A) true (B) false,A,"A ribosome is a small organelle where proteins are made. Its like a factory in the cell. It gathers amino acids and joins them together into proteins. Unlike other organelles, the ribosome is not surrounded by a membrane. As a result, some scientists do not classify it as an organelle. Ribosomes may be found floating in the cytoplasm. Some ribosomes are located on the surface of another organelle, the endoplasmic reticulum. "
translation translates from one language to another.,(A) true (B) false,A,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
"during translation, the mrna is translated from __________ into __________.",(A) nucleic acid (B) amino acids (C) b nucleotides (D) protein (E) c nucleotides (F) amino acids (G) d nucleic acid (H) protein,C,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
what is the role of the trna molecules?,(A) The tRNA determines the order of the amino acids in the protein (B) The tRNA reads the mRNA code and brings a specific amino acid to the (C) The tRNA brings the genetic message to the ribosome from the nucleus (D) all of the above,B,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
what is the sequence of the anticodon that binds to a cua codon?,(A) GAU (B) GAT (C) CUA (D) CTA,A,"The mRNA, which is transcribed from the DNA in the nucleus, carries the directions for the protein-making process. mRNA tells the ribosome ( Figure 1.1) how to create a specific protein. Ribosomes translate RNA into a protein with a specific amino acid sequence. The tRNA binds and brings to the ribosome the amino acid encoded by the mRNA. The process of reading the mRNA code in the ribosome to make a protein is called translation ( Figure 1.2): the mRNA is translated from the language of nucleic acids (nucleotides) to the language of proteins (amino acids). Sets of three bases, called codons, are read in the ribosome, the organelle responsible for making proteins. This summary of how genes are ex- pressed shows that DNA is transcribed into RNA, which is translated, in turn, to protein. The one letter code represents amino acids. The following are the steps involved in translation: mRNA travels to the ribosome from the nucleus. The following steps occur in the ribosome: The base code in the mRNA determines the order of the amino acids in the protein. The genetic code in mRNA is read in words of three letters (triplets), called codons. Each codon codes for an amino acid. There are 20 amino acids used to make proteins, and different codons code for different amino acids. For example, GGU codes for the amino acid glycine, while GUC codes for valine. tRNA reads the mRNA code and brings a specific amino acid to attach to the growing chain of amino acids. The anticodon on the tRNA binds to the codon on the mRNA. Each tRNA carries only one type of amino acid and only recognizes one specific codon. For example, a GGC anticodon will bind to a CCG codon, and a CGA anticodon will bind to a GCU codon. tRNA is released from the amino acid. Three codons, UGA, UAA, and UAG, indicate that the protein should stop adding amino acids. They are called stop codons and do not code for an amino acid. Once tRNA comes to a stop codon, the protein is set free from the ribosome. The following chart ( Figure 1.3) is used to determine which amino acids correspond to which codons. "
which of the following statements concerning codons is true?,(A) Codons are read in the ribosome (B) Codons are found in the mRNA sequence (C) Codons consist of three RNA bases (D) All of the above statements are true,D,The genetic code has three other important characteristics. The genetic code is the same in all living things. This shows that all organisms are related by descent from a common ancestor. Each codon codes for just one amino acid (or start or stop). This is necessary so the correct amino acid is always selected. Most amino acids are encoded by more than one codon. This is helpful. It reduces the risk of the wrong amino acid being selected if there is a mistake in the code. 
"ggg codes for glycine and ccc codes for proline. if the sequence within a gene is ggggggcccgggccc, what is the amino acid sequence of the corresponding protein?",(A) Gly-Gly-Pro-Gly-Pro (B) Pro-Pro-Gly-Pro-Gly (C) Gly-Gly-Pro-Pro-Gly (D) Pro-Pro-Gly-Gly-Pro,B,"How is the information for making proteins encoded in DNA? The answer is the genetic code. The genetic code is based on the sequence of nitrogen bases in DNA. The four bases make up the letters of the code. Groups of three bases each make up code words. These three-letter code words are called codons. Each codon stands for one amino acid or else for a start or stop signal. There are 20 amino acids that make up proteins. With three bases per codon, there are 64 possible codons. This is more than enough to code for the 20 amino acids plus start and stop signals. You can see how to translate the genetic code in Figure 5.17. Start at the center of the chart for the first base of each three-base codon. Then work your way out from the center for the second and third bases. Find the codon AUG in Figure 5.17. It codes for the amino acid methionine. It also codes for the start signal. After an AUG start codon, the next three letters are read as the second codon. The next three letters after that are read as the third codon, and so on. You can see how this works in Figure 5.18. The figure shows the bases in a molecule "
not all echinoderms have the ability to move around.,(A) true (B) false,A,"While almost all echinoderms live on the sea floor, some sea-lilies can swim at great speeds for brief periods of time, and a few sea cucumbers are fully floating. Some echinoderms find other ways of moving. For example, crinoids attach themselves to floating logs, and some sea cucumbers move by attaching to the sides of fish. On the underside side of a sea star, there are hundreds of tiny feet usually arranged into several rows on each ray of the star. These are called tube feet, or podia, and are filled with seawater in most echinoderms. The water vascular system within the body of the animal is also filled with seawater. By expanding and contracting chambers within the water vascular system, the echinoderm can force water into certain tube feet to extend them. The animal has muscles in the tube feet, which are used to retract them. By expanding and retracting the right tube feet in the proper order, the animal can walk. "
sand dollars can be found both in the ocean and on land.,(A) true (B) false,B,"When you take a walk along a beach, what do you find there? Sand, the ocean, lots of sunlight. You may also find shells. The shells you find are most likely left by organisms in the phylum Mollusca. On the beach, you can find the shells of many different mollusks ( Figure 1.1), including clams, mussels, scallops, oysters, and snails. Mollusks are invertebrates that usually have a hard shell, a mantle, and a radula. Their glossy pearls, mother of pearl, and abalone shells are like pieces of jewelry. Some mollusks, such as squid and octopus, do not have shells. "
which is a characteristic of a starfish?,(A) capture prey for their own food (B) bottom feeders with long (C) narrow arms (D) c have movable spines (E) d armless and elongated,A,"As mentioned earlier, echinoderms show radial symmetry. Other key echinoderm features include an internal skeleton and spines, as well as a few organs and organ systems. Although echinoderms look like they have a hard exterior, they do not have an external skeleton. Instead, a thin outer skin covers an internal skeleton made of tiny plates and spines. This provides rigid support. Some groups of echinoderms, such as sea urchins ( Figure 1.2), have spines that protect the organism. Sea cucumbers use these spines to help them move. A starfish (left) and a keyhole sand dollar (right), showing the radial symmetry char- acteristic of the echinoderms. Starfish are also known as sea stars. Another echinoderm, a sea urchin (Echi- nus esculentus), showing its spines. Echinoderms have a unique water vascular system. This network of fluid-filled tubes helps them to breathe, eat, and move. Therefore, they can function without gill slits. Echinoderms also have a very simple digestive system, circulatory system, and nervous system. The digestive system often leads directly from the mouth to the anus. The echinoderms have an open circulatory system, meaning that fluid moves freely in the body cavity. But echinoderms have no heart. This may be due to their simple radial symmetry - a heart is not needed to pump the freely moving fluid. The echinoderm nervous system is a nerve net, or interconnected neurons with no central brain. Many echinoderms have amazing powers of regeneration. For example, some sea stars (starfish) are capable of regenerating lost arms. In some cases, lost arms have been observed to regenerate a second complete sea star! Sea cucumbers often release parts of their internal organs if they perceive danger. The released organs and tissues are then quickly regenerated. "
which is a characteristic of a brittle star?,(A) capture prey for their own food (B) bottom feeders with long (C) narrow arms (D) c have movable spines (E) d armless and elongated,B,"Fragmentation occurs when a piece breaks off from a parent organism. Then the piece develops into a new organism. Sea stars, like the one in Figure 5.10, can reproduce this way. In fact, a new sea star can form from a single arm. "
which echinoderms are able to move relatively quickly?,(A) sea cucumbers (B) sand dollars (C) asteroids (D) brittle stars,D,"The echinoderms can be divided into two major groups: 1. Eleutherozoa are the echinoderms that can move. This group includes the starfish and most other echinoderms. 2. Pelmatozoa are the immobile echinoderms. This group includes crinoids, such as the feather stars. Listed below are the four main classes of echinoderms present in the Eleutherozoa Group ( Table 1.1). Class Asteroidea Ophiuroidea Representative Organisms Starfish and asteroids Brittle stars ( Figure 1.1) Echinoidea Sea urchins and sand dollars Holothuroidea Sea cucumbers Characteristics Capture prey for their own food. Bottom feeders with long, narrow, flexible arms that allow relatively fast movement. Have movable spines which are used for movement, defense, and sensing the environment. Armless, elongated, generally soft- "
which echinoderms have movable spines?,(A) sand dollars (B) starfish (C) sea cucumbers (D) brittle stars,A,"The echinoderms can be divided into two major groups: 1. Eleutherozoa are the echinoderms that can move. This group includes the starfish and most other echinoderms. 2. Pelmatozoa are the immobile echinoderms. This group includes crinoids, such as the feather stars. Listed below are the four main classes of echinoderms present in the Eleutherozoa Group ( Table 1.1). Class Asteroidea Ophiuroidea Representative Organisms Starfish and asteroids Brittle stars ( Figure 1.1) Echinoidea Sea urchins and sand dollars Holothuroidea Sea cucumbers Characteristics Capture prey for their own food. Bottom feeders with long, narrow, flexible arms that allow relatively fast movement. Have movable spines which are used for movement, defense, and sensing the environment. Armless, elongated, generally soft- "
echinoderms that cannot move include,(A) feather stars (B) starfish (C) sand dollars (D) none of the above,A,"The echinoderms can be divided into two major groups: 1. Eleutherozoa are the echinoderms that can move. This group includes the starfish and most other echinoderms. 2. Pelmatozoa are the immobile echinoderms. This group includes crinoids, such as the feather stars. Listed below are the four main classes of echinoderms present in the Eleutherozoa Group ( Table 1.1). Class Asteroidea Ophiuroidea Representative Organisms Starfish and asteroids Brittle stars ( Figure 1.1) Echinoidea Sea urchins and sand dollars Holothuroidea Sea cucumbers Characteristics Capture prey for their own food. Bottom feeders with long, narrow, flexible arms that allow relatively fast movement. Have movable spines which are used for movement, defense, and sensing the environment. Armless, elongated, generally soft- "
"vegetable oil, olive oil, and nuts are good sources of carbohydrates.",(A) true (B) false,B,"Carbohydrates are nutrients that include sugars, starches, and fiber. There are two types of carbohydrates: simple and complex. Pictured below are some foods that are good sources of carbohydrates ( Figure 1.1). "
unsaturated lipids are needed in small amounts for good health.,(A) true (B) false,A,"Lipids are nutrients, such as fats that store energy. Lipids also have several other roles in the body. For example, lipids protect nerves and make up the membranes that surround cells. Fats are one type of lipid. Stored fat gives your body energy to use for later. Its like having money in a savings account: its there in case you need it. Stored fat also cushions and protects internal organs. In addition, it insulates the body. It helps keep you warm in cold weather. Between the ages of 9 and 13 years, you need about 34 grams of proteins a day. Seafood and eggs are other good sources of protein. There are two main types of fats, saturated and unsaturated. 1. Saturated fats can be unhealthy, even in very small amounts. They are found mainly in animal foods, such as meats, whole milk, and eggs. So even though these foods are good sources of proteins, they should be eaten in limited amounts. Saturated lipids increase cholesterol levels in the blood. Too much cholesterol in the blood Another type of lipid is called trans fat. Trans fats are manufactured and added to certain foods to keep them fresher for longer. Foods that contain trans fats include cakes, cookies, fried foods, and margarine. Eating foods that contain trans fats increases the risk of heart disease. Beginning with Denmark in 2003, many nations now limit the amount of trans fat that can be in food products or ban these products all together. On January 1, 2008, Calgary became the first city in Canada to ban trans fats from restaurants and fast food chains. Beginning in 2010, California banned trans fats from restaurant products, and in 2011, from all retail baked goods. "
what makes up the membrane that surrounds cells?,(A) carbohydrates (B) lipids (C) proteins (D) amino acids,B,The cell membrane is like the bag holding the Jell-O. It encloses the cytoplasm of the cell. It forms a barrier between the cytoplasm and the environment outside the cell. The function of the cell membrane is to protect and support the cell. It also controls what enters or leaves the cell. It allows only certain substances to pass through. It keeps other substances inside or outside the cell. 
most lipids in your diet should be,(A) trans fats (B) saturated fats (C) unsaturated fats (D) None (E) your diet should not contain any lipid,C,"Lipids are nutrients such as fats. They are used for energy and other important purposes. One gram of lipids provides the body with 9 Calories of energy, more than twice as much as carbohydrates or proteins. Lipids also make up cell membranes, protect nerves, control blood pressure, and help blood clot. You must consume some lipids for these purposes. Good food sources of lipids are shown in Figure 17.4. Any extra lipids you consume are stored as fat. A certain amount of stored fat is needed to cushion and protect internal organs and insulate the body. However, too much stored fat can lead to obesity and cause significant health problems. A type of lipid called trans fat is found in many processed foods. Trans fat is rare in nature but is manufactured and added to foods to preserve freshness. Eating foods that contain trans fat increases the risk of heart disease. Trans fat may be found in such foods as cookies, doughnuts, crackers, fried foods, ground beef, and margarine. "
which statement is associated with starch?,(A) Starches are found in vegetables and grains (B) Starch is made of thousands of glucose monomers (C) Starch is a large (D) complex carbohydrate (E) d All of the above describe starch,D,"Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. "
why are complex carbohydrates better than simple carbohydrates?,(A) They have carbohydrates that are good for you (B) They provide energy longer and more steadily (C) They are found in fruit (D) all of the above,B,"Starch is a large, complex carbohydrate made of thousands of glucose units (monomers) joined together. Starches are found in foods such as vegetables and grains. Starches are broken down by the body into sugars that provide energy. Breads and pasta are good sources of complex carbohydrates. Fiber is another type of large, complex carbohydrate that is partly indigestible. Unlike sugars and starches, fiber does not provide energy. However, it has other important roles in the body. For example, fiber is important for maintaining the health of your gastrointestinal tract. Eating foods high in fiber also helps fill you up without providing too many calories. Most fruits and vegetables are high in fiber. Some examples are pictured below ( Figure 1.2). "
what type of nutrient is fiber?,(A) carbohydrate (B) lipid (C) protein (D) unsaturated fat,A,"Carbohydrates are nutrients that include sugars, starches, and fiber. There are two types of carbohydrates: simple and complex. Pictured below are some foods that are good sources of carbohydrates ( Figure 1.1). "
the urinary system is the same as the excretory system.,(A) true (B) false,B,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
urine is mostly water.,(A) true (B) false,A,"Urine is a liquid that is formed by the kidneys when they filter wastes from the blood. Urine contains mostly water, but it also contains salts and nitrogen-containing molecules. The amount of urine released from the body depends on many things. Some of these include the amount of fluid and food a person consumes and how much fluid they have lost from sweating and breathing. Urine ranges from colorless to dark yellow but is usually a pale yellow color. Light yellow urine contains mostly water. The darker the urine, the less water it contains. The urinary system also removes a type of waste called urea from your blood. Urea is a nitrogen-containing molecule that is made when foods containing protein, such as meat, poultry, and certain vegetables, are broken down in the body. Urea and other wastes are carried in the bloodstream to the kidneys, where they are removed and form urine. "
what brings urine from the kidneys to the urinary bladder?,(A) the urine tubes (B) the ureters (C) the urethra (D) the kidney tubes,B,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
what is the organ that collects urine?,(A) the kidneys (B) the ureters (C) the urinary bladder (D) the urinary container,C,"1. As you can see above ( Figure 1.1), the kidneys are two bean-shaped organs. Kidneys filter and clean the blood and form urine. They are about the size of your fists and are found near the middle of the back, just below your ribcage. 2. Ureters are tube-shaped and bring urine from the kidneys to the urinary bladder. 3. The urinary bladder is a hollow and muscular organ. It is shaped a little like a balloon. It is the organ that collects urine. 4. Urine leaves the body through the urethra. The kidneys filter the blood that passes through them, and the urinary bladder stores the urine until it is released from the body. "
urine leaves the body through the,(A) ureter (B) bladder (C) urethra (D) kidneys,C,"From the kidneys, urine enters the ureters. These are two muscular tubes that carry urine to the urinary bladder. Contractions of the muscles of the ureters move the urine along by peristalsis. The urinary bladder is a sac-like organ that stores urine. When the bladder is about half full, a sphincter relaxes to let urine flow out of the bladder and into the urethra. The urethra is a muscular tube that carries urine out of the body through another sphincter. The process of urine leaving the body is called urination. The second sphincter and the process of urination are normally under conscious control. "
which organ is not part of the urinary system?,(A) the kidney (B) the ribcage (C) the urethra (D) the bladder,B,"Sometimes, the urinary system ( Figure 1.1) is called the excretory system. But the urinary system is only one part of the excretory system. Recall that the excretory system is also made up of the skin, lungs, and large intestine, as well as the kidneys. The urinary system is the organ system that makes, stores, and gets rid of urine. "
which organ is not part of the excretory system?,(A) the kidney (B) the lungs (C) the heart (D) the large intestine,C,"Excretion is any process in which excess water or wastes are removed from the body. Excretion is the job of the excretory system. Besides the kidneys, other organs of excretion include the large intestine, liver, skin and lungs. The large intestine eliminates food wastes that remain after digestion takes place. The liver removes excess amino acids and toxins from the blood. Sweat glands in the skin excrete excess water and salts in sweat. The lungs exhale carbon dioxide and also excess water as water vapor. Each of the above organs of excretion is also part of another body system. For example, the large intestine and liver are part of the digestive system, and the lungs are part of the respiratory system. The kidneys are the main organs of excretion. They are part of the urinary system. "
about 1 of every 2 people need some sort of vision correction.,(A) true (B) false,A,You probably know people who need eyeglasses or contact lenses to see clearly. Maybe you need them yourself. Lenses are used to correct vision problems. Two of the most common vision problems are myopia and hyperopia. 
signs of myopia usually begin in childhood.,(A) true (B) false,A,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
an object is focused in front of the retina. this person has,(A) myopia (B) hyperopia (C) nearsightedness (D) both a and c,D,"Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure 1.1 shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it. Q: Sometimes squinting the eyes can help someone see more clearly. Why do you think this works? A: Squinting may improve focus by slightly changing the shape of the eyes. When you squint, you tighten muscles around the eyes, putting pressure on the eyeballs. "
an object is focused in back of the retina. this person has,(A) myopia (B) hyperopia (C) nearsightedness (D) both a and c,B,"Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure 1.2). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. Q: Joey has hyperopia. When is he more likely to need his glasses: when he reads a book or when he watches TV? A: With hyperopia, Joey is farsighted. He can probably see the TV more clearly than the words in a book because the TV is farther away. Therefore, he is more likely to need his glasses when he reads than when he watches TV. "
common signs of myopia include,(A) difficulty in maintaining a clear focus on close objects (B) difficulty is seeing the whiteboard at school (C) headaches after close work (D) all of the above,B,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
what is the main goal of corrective lenses?,(A) The corrective lens changes the focus (B) so images move through the cornea (C) b The corrective lens changes the focus (D) so images moves through the eye lens (E) c The corrective lens changes the focus (F) so images move through the pupil (G) d The corrective lens changes the focus (H) so images fall on the retina,D,You probably know people who need eyeglasses or contact lenses to see clearly. Maybe you need them yourself. Lenses are used to correct vision problems. Two of the most common vision problems are myopia and hyperopia. 
people with myopia will usually need glasses or contact lenses when they,(A) work at a computer (B) read a book (C) watch TV or drive a car (D) all of the above,C,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
minerals are organic compounds.,(A) true (B) false,B,"A mineral is an inorganic substance. It was not made by living organisms. Organic substances contain carbon. Some organic substances are proteins, carbohydrates, and oils. Everything else is inorganic. In a few cases, living organisms make inorganic materials. The calcium carbonate shells made by marine animals are inorganic. "
vitamins are a good source of energy.,(A) true (B) false,B,"Vitamins and minerals are also nutrients. They do not provide energy, but they are needed for good health. "
what minerals are needed for muscles and nerves to work normally?,(A) potassium and phosphorus (B) potassium and sodium (C) calcium and phosphorus (D) calcium and magnesium,B,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
what vitamin is important in blood clotting?,(A) vitamin A (B) vitamin B9 (C) vitamin C (D) vitamin K,D,"Platelets ( Figure 1.4) are very small, but they are very important in blood clotting. Platelets are not cells. They are sticky little pieces of larger cells. Platelets bud off large cells that stay in the bone marrow. When a blood vessel gets cut, platelets stick to the injured areas. They release chemicals called clotting factors, which cause proteins to form over the wound. This web of proteins catches red blood cells and forms a clot. This clot stops more blood from leaving the body through the cut blood vessel. The clot also stops bacteria from entering the body. Platelets survive in the blood for ten days before they are removed by the liver and spleen. "
"what vitamin can be found in foods like oranges, grapefruits, and broccoli?",(A) vitamin A (B) vitamin C (C) vitamin D (D) vitamin K,B,"Vitamins are organic compounds that the body needs in small amounts to function properly. Humans need 13 different vitamins. Some of them are listed below ( Table 1.1). The table also shows how much of each vitamin you need every day. Vitamins have many roles in the body. For example, Vitamin A helps maintain good vision. Vitamin B9 helps form red blood cells. Vitamin K is needed for blood to clot when you have a cut or other wound. Vitamin Necessary for Available from Daily Amount Required (at ages 913 years) Vitamin Necessary for Available from A Good vision B1 Healthy nerves B3 Healthy skin and nerves B9 Red blood cells B12 Healthy nerves C Growth and repair of tis- sues Healthy bones and teeth Blood to clot Carrots, spinach, milk, eggs Whole wheat, peas, meat, beans, fish, peanuts Beets, liver, pork, turkey, fish, peanuts Liver, peas, dried beans, leafy green vegetables Meat, liver, milk, shell- fish, eggs Oranges, grapefruits, red peppers, broccoli Milk, salmon, tuna, eggs Spinach, brussels sprouts, milk, eggs D K Daily Amount Required (at ages 913 years) 600 g (1 g = 1  106 g) 0.9 mg (1 mg = 1  103 g) 12 mg 300 g 1.8 g 45 mg 5 g 60 g Some vitamins are produced in the body. For example, vitamin D is made in the skin when it is exposed to sunlight. Vitamins B12 and K are produced by bacteria that normally live inside the body. Most other vitamins must come from foods. Foods that are good sources of vitamins include whole grains, vegetables, fruits, and milk ( Table 1.1). Not getting enough vitamins can cause health problems. For example, too little vitamin C causes a disease called scurvy. People with scurvy have bleeding gums, nosebleeds, and other symptoms. "
low levels of what mineral may cause osteoporosis?,(A) calcium (B) magnesium (C) potassium (D) sodium,A,"Osteoporosis is a disease in which the bones become porous and weak because they do not contain enough calcium. The graph in Figure 16.14 shows how the mass of calcium in bone peaks around age 30 and declines after that, especially in women. Maximizing the calcium in your bones while youre young will reduce your risk of developing osteoporosis later in of life. "
what mineral can be found in bananas?,(A) chloride (B) magnesium (C) phosphorus (D) potassium,D,"Minerals are chemical elements that are needed for body processes. Minerals that you need in relatively large amounts are listed below ( Table 1.2). Minerals that you need in smaller amounts include iodine, iron, and zinc. Minerals have many important roles in the body. For example, calcium and phosphorus are needed for strong bones and teeth. Potassium and sodium are needed for muscles and nerves to work normally. Mineral Necessary for Available from Calcium Strong bones and teeth Chloride Magnesium Proper balance of water and salts in body Strong bones Phosphorus Strong bones and teeth Potassium Muscles and nerves to work normally Muscles and nerves to work normally Milk, soy milk, leafy green vegetables Table salt, most packaged foods Whole grains, leafy green vegetables, nuts Meat, poultry, whole grains Meats, grains, bananas, orange juice Table salt, most packaged foods Sodium Daily Amount Required (at ages 913 years) 1,300 mg 2.3 g 240 mg 1,250 mg 4.5 g 1.5 g Your body cannot produce any of the minerals that it needs. Instead, you must get minerals from the foods you eat. Good sources of minerals include milk, leafy green vegetables, and whole grains ( Table 1.2). Not getting enough minerals can cause health problems. For example, too little calcium may cause osteoporosis. This is a disease in which bones become soft and break easily. Getting too much of some minerals can also cause health problems. Many people get too much sodium. Sodium is added to most packaged foods. People often add more sodium to their food by using table salt. Too much sodium causes high blood pressure in some people. "
Acids turn blue litmus paper red.,(A) true (B) false,A,"Certain compounds, called indicators, change color when acids come into contact with them, so indicators can be used to detect acids. An example of an indicator is the compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of acid on a strip of blue litmus paper, the paper will turn red. You can see this in the Figure 1.2. Litmus isnt the only indicator for detecting acids. Red cabbage juice also works well, as you can see in this entertaining video. Click image to the left or use the URL below. URL:  Drawing of blue litmus paper turning red in acid. "
Which of the following substances has a pH greater than 7?,(A) normal (clean) rain (B) orange juice (C) bananas (D) soap,D,"The strength of acids and bases is measured on a scale called the pH scale, which is shown in the Figure 1.1. By definition, pH represents the acidity, or hydrogen ion (H+ ) concentration, of a solution. Pure water, which is neutral, has a pH of 7. With a higher the concentration of hydrogen ions, a solution is more acidic and has a lower pH. Acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. Its important to realize that the pH scale is based on powers of ten. For example, a solution with a pH of 8 is 10 times more basic than a solution with a pH of 7, and a solution with a pH of 9 is 100 times more basic than a solution with a pH of 7. Q: How much more acidic is a solution with a pH of 4 than a solution with a pH of 7? A: A solution with a pH of 4 is 1000 (10  10  10, or 103 ) times more acidic than a solution with a pH of 7. Q: Which solution on the pH scale in the Figure 1.1 is the weakest acid? Which solution is the strongest base? A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14. "
Sodium chloride is an example of a base.,(A) true (B) false,B,"Bases are ionic compounds that produce negative hydroxide ions (OH ) when dissolved in water. An ionic com- pound contains positive metal ions and negative nonmetal ions held together by ionic bonds. (Ions are atoms that have become charged particles because they have either lost or gained electrons.) An example of a base is sodium hydroxide (NaOH). When it dissolves in water, it produces negative hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: H O 2 NaOH OH + Na+ "
Acids produce hydrogen gas when they react with,(A) salts (B) bases (C) water (D) metals,D,"You already know that a sour taste is one property of acids. (Warning: Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Acids can also react with metals, and when they do they produce hydrogen gas. An example of this type of reaction is hydrochloric acid reacting with the metal zinc (Zn). The reaction is pictured in the Figure 1.1. It can be represented by the chemical equation: Zn + 2HCl  H2 + ZnCl2 Q: What sign indicates that a gas is being produced in this reaction? A: The bubbles are hydrogen gas rising through the acid. Q: Besides hydrogen gas, what else is produced in this reaction? A: This reaction also produces zinc chloride ZnCl2 , which is a neutral ionic compound called a salt. "
Bases cannot conduct electricity.,(A) true (B) false,B,"All bases share certain properties, including a bitter taste. (Warning: Never taste an unknown substance to see whether it is a base!) Bases also feel slippery. Think about how slippery soap feels. Thats because its a base. In addition, bases conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Q: Bases are closely related to compounds called acids. How are their properties similar? How are they different? A: A property that is shared by bases and acids is the ability to conduct electricity when dissolved in water. Some ways bases and acids are different is that acids taste sour whereas bases taste bitter. Also, acids but not bases react with metals. "
Properties of bases include,(A) a sour taste (B) a slippery feel (C) the ability to conduct electricity (D) two of the above,D,"All bases share certain properties, including a bitter taste. (Warning: Never taste an unknown substance to see whether it is a base!) Bases also feel slippery. Think about how slippery soap feels. Thats because its a base. In addition, bases conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Q: Bases are closely related to compounds called acids. How are their properties similar? How are they different? A: A property that is shared by bases and acids is the ability to conduct electricity when dissolved in water. Some ways bases and acids are different is that acids taste sour whereas bases taste bitter. Also, acids but not bases react with metals. "
Which of the following acids is strongest?,(A) sulfuric acid (B) lemon juice (C) acid rain (D) vinegar,A,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
All acids are harmful.,(A) true (B) false,B,"With so many species of bacteria, some are bound to be harmful. Harmful bacteria can make you sick. They can also ruin food and be used to hurt people. "
A strong acid has a high concentration of hydrogen ions.,(A) true (B) false,A,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
Products of a neutralization reaction include,(A) hydroxide ions (B) hydrogen ions (C) water (D) two of the above,C,"When an acid and a base react, the reaction is called a neutralization reaction. Thats because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. Lets see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is: NaOH + HCl  H2 O and NaCl Now lets break this reaction down into two parts to see how each product forms. Positive hydrogen ions from HCl and negative hydroxide ions from NaOH combine to form water. This part of the reaction can be represented by the equation: H+ + OH  H2 O Positive sodium ions from NaOH and negative chloride ions from HCL combine to form the salt sodium chloride (NaCl), commonly called table salt. This part of the reaction can be represented by the equation: Na+ + Cl  NaCl Another example of a neutralization reaction can be seen in the Figure 1.1. Q: What products are produced when antacid tablets react with hydrochloric acid in the stomach? A: The products are water and the salt calcium chloride (CaCl2 ). Carbon dioxide (CO2 ) is also produced. The reaction is represented by the chemical equation: CaCO3 + 2HCl  H2 O + CaCl2 + CO2 "
The symbol pH represents acidity.,(A) true (B) false,A,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
Ammonia is a stronger base than is bleach.,(A) true (B) false,B,"The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. "
Acids are used to make fertilizer.,(A) true (B) false,A,"Acids have many important uses, especially in industry. For example, sulfuric acid is used to manufacture a variety of different products, including paper, paint, and detergent. Some other uses of acids are be seen in the Figure 1.3. "
Acid rain promotes rapid growth of plants.,(A) true (B) false,B,"Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. If acid rain falls into lakes, it lowers the pH of the water and may kill aquatic organisms. If it falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may make them sick or even kill them. Acid rain also damages stone buildings, bridges, and statues, like the one in Figure 25.1. "
Normal (clean) rainwater has a pH of 7.,(A) true (B) false,B,"Acid rain water is more acidic than normal rain water. Acidity is measured on the pH scale. Lower numbers are more acidic and higher numbers are less acidic (also called more alkaline) (Figure 1.3). Natural rain is somewhat acidic, with a pH of 5.6; acid rain must have a pH of less than 5.0. A small change in pH represents a large change in acidity: rain with a pH of 4.6 is 10 times more acidic than normal rain (with a pH of 5.6). Rain with a pH of 3.6 is 100 times more acidic. Regions with a lot of coal-burning power plants have the most acidic rain. The acidity of average rainwater in the northeastern United States has fallen to between 4.0 and 4.6. Acid fog has even lower pH with an average of around 3.4. One fog in Southern California in 1986 had a pH of 1.7, equal to toilet-bowl cleaner. In arid climates, such as in Southern California, acids deposit on the ground dry. Acid precipitation ends up on the land surface and in water bodies. Some forest soils in the northeast are five to ten times more acidic than they were two or three decades ago. Acid droplets move down through acidic soils to lower the pH of streams and lakes even more. Acids strip soil of metals and nutrients, which collect in streams and lakes. As a result, stripped soils may no longer provide the nutrients that native plants need. A pH scale goes from 1 to 14; numbers are shown with the pH of some common substances. A value of 7 is neutral. The strongest acids are at the low end of the scale and the strongest bases are at the high end. "
Litmus is the only indicator for detecting acids and bases.,(A) true (B) false,B,"Certain compounds, called indicators, change color when acids come into contact with them, so indicators can be used to detect acids. An example of an indicator is the compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of acid on a strip of blue litmus paper, the paper will turn red. You can see this in the Figure 1.2. Litmus isnt the only indicator for detecting acids. Red cabbage juice also works well, as you can see in this entertaining video. Click image to the left or use the URL below. URL:  Drawing of blue litmus paper turning red in acid. "
type of chemical reaction in which an acid reacts with a base,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,G,"As you read above, an acid produces positive hydrogen ions and a base produces negative hydroxide ions. If an acid and base react together, the hydrogen and hydroxide ions combine to form water. This is represented by the equation: H+ + OH ! H2 O An acid also produces negative ions, and a base also produces positive ions. For example, the acid hydrogen chloride (HCl), when dissolved in water, produces negative chloride ions (Cl ) as well as hydrogen ions. The base sodium hydroxide (NaOH) produces positive sodium ions (Na+ ) in addition to hydroxide ions. These other ions also combine when the acid and base react. They form sodium chloride (NaCl). This is represented by the equation: Na+ + Cl ! NaCl Sodium chloride is called table salt, but salt is a more general term. A salt is any ionic compound that forms when an acid and base react. It consists of a positive ion from the base and a negative ion from the acid. Like pure water, a salt is neutral in pH. Thats why reactions of acids and bases are called neutralization reactions. Another example of a neutralization reaction is described in Figure 10.12. You can learn more about salts and how they form at this URL:  (13:21). MEDIA Click image to the left or use the URL below. URL: "
Acids have many important uses in industry.,(A) true (B) false,A,"Acids have many important uses, especially in industry. For example, sulfuric acid is used to manufacture a variety of different products, including paper, paint, and detergent. Some other uses of acids are be seen in the Figure 1.3. "
ionic compound that produces hydroxide ions when dissolved in water,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,C,"A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ "
ionic compound formed when an acid and a base react,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,E,"As you read above, an acid produces positive hydrogen ions and a base produces negative hydroxide ions. If an acid and base react together, the hydrogen and hydroxide ions combine to form water. This is represented by the equation: H+ + OH ! H2 O An acid also produces negative ions, and a base also produces positive ions. For example, the acid hydrogen chloride (HCl), when dissolved in water, produces negative chloride ions (Cl ) as well as hydrogen ions. The base sodium hydroxide (NaOH) produces positive sodium ions (Na+ ) in addition to hydroxide ions. These other ions also combine when the acid and base react. They form sodium chloride (NaCl). This is represented by the equation: Na+ + Cl ! NaCl Sodium chloride is called table salt, but salt is a more general term. A salt is any ionic compound that forms when an acid and base react. It consists of a positive ion from the base and a negative ion from the acid. Like pure water, a salt is neutral in pH. Thats why reactions of acids and bases are called neutralization reactions. Another example of a neutralization reaction is described in Figure 10.12. You can learn more about salts and how they form at this URL:  (13:21). MEDIA Click image to the left or use the URL below. URL: "
When sodium hydroxide dissolves in water it forms hydrogen ions.,(A) true (B) false,B,"A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ "
concentration of hydrogen ions in a solution,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,B,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
A neutral substance has a pH of 7.,(A) true (B) false,A,"The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. "
A salt forms when an acid and base react.,(A) true (B) false,A,"As you read above, an acid produces positive hydrogen ions and a base produces negative hydroxide ions. If an acid and base react together, the hydrogen and hydroxide ions combine to form water. This is represented by the equation: H+ + OH ! H2 O An acid also produces negative ions, and a base also produces positive ions. For example, the acid hydrogen chloride (HCl), when dissolved in water, produces negative chloride ions (Cl ) as well as hydrogen ions. The base sodium hydroxide (NaOH) produces positive sodium ions (Na+ ) in addition to hydroxide ions. These other ions also combine when the acid and base react. They form sodium chloride (NaCl). This is represented by the equation: Na+ + Cl ! NaCl Sodium chloride is called table salt, but salt is a more general term. A salt is any ionic compound that forms when an acid and base react. It consists of a positive ion from the base and a negative ion from the acid. Like pure water, a salt is neutral in pH. Thats why reactions of acids and bases are called neutralization reactions. Another example of a neutralization reaction is described in Figure 10.12. You can learn more about salts and how they form at this URL:  (13:21). MEDIA Click image to the left or use the URL below. URL: "
ionic compound that produces hydrogen ions when dissolved in water,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,A,"An acid is an ionic compound that produces positive hydrogen ions (H+ ) when dissolved in water. An example is hydrogen chloride (HCl). When it dissolves in water, its hydrogen ions and negative chloride ions (Cl ) separate, forming hydrochloric acid. This can be represented by the equation: HCl H2 O + ! H + Cl "
measure of the acidity of a solution,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,D,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
compound used to detect acids and bases,(A) acid (B) acidity (C) base (D) pH (E) salt (F) litmus (G) neutralization,F,"Certain compounds, called indicators, change color when bases come into contact with them, so they can be used to detect bases. An example of an indicator is a compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of a base on a strip of red litmus paper, the paper will turn blue. You can see this in the Figure 1.1. Litmus isnt the only detector of bases. Red cabbage juice can also detect bases, as you can see in this video. Click image to the left or use the URL below. URL:  Drawing of red litmus paper turning blue in a base. "
Which of the following substances is an acid?,(A) milk (B) bleach (C) ammonia (D) seawater,A,"You already know that a sour taste is one property of acids. (Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity because they consist of charged particles in solution. Acids also react with metals to produce hydrogen gas. For example, when hydrochloric acid (HCl) reacts with the metal magnesium (Mg), it produces magnesium chloride (MgCl2 ) and hydrogen (H2 ). This is a single replacement reaction, represented by the chemical equation: Mg + 2HCl ! H2 + MgCl2 You can see an online demonstration of a similar reaction at this URL: "
A very strong base has a pH close to,(A) 1 (B) 5 (C) 7 (D) 14,D,"The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. "
Properties of acids include,(A) a bitter taste (B) a slippery feel (C) the ability to conduct electricity (D) two of the above,C,"You already know that a sour taste is one property of acids. (Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity because they consist of charged particles in solution. Acids also react with metals to produce hydrogen gas. For example, when hydrochloric acid (HCl) reacts with the metal magnesium (Mg), it produces magnesium chloride (MgCl2 ) and hydrogen (H2 ). This is a single replacement reaction, represented by the chemical equation: Mg + 2HCl ! H2 + MgCl2 You can see an online demonstration of a similar reaction at this URL: "
Which of the following ionic compounds forms an acid when dissolved in water?,(A) KCl (B) HCl (C) NaCl (D) MgCl2,B,"An acid is an ionic compound that produces positive hydrogen ions (H+ ) when dissolved in water. An example is hydrogen chloride (HCl). When it dissolves in water, its hydrogen ions and negative chloride ions (Cl ) separate, forming hydrochloric acid. This can be represented by the equation: HCl H2 O + ! H + Cl "
Bases are used to make all of the following products except,(A) soap (B) concrete (C) deodorant (D) car batteries,D,"Bases are used for a variety of purposes. For example, soaps contain bases such as potassium hydroxide. Other uses of bases are pictured in Figure 10.9. "
"If a solution has a greater concentration of hydrogen ions than does pure water, then the solution",(A) has a pH greater than 7 (B) is a base (C) is an acid (D) two of the above,C,"The strength of acids and bases is measured on a scale called the pH scale, which is shown in the Figure 1.1. By definition, pH represents the acidity, or hydrogen ion (H+ ) concentration, of a solution. Pure water, which is neutral, has a pH of 7. With a higher the concentration of hydrogen ions, a solution is more acidic and has a lower pH. Acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. Its important to realize that the pH scale is based on powers of ten. For example, a solution with a pH of 8 is 10 times more basic than a solution with a pH of 7, and a solution with a pH of 9 is 100 times more basic than a solution with a pH of 7. Q: How much more acidic is a solution with a pH of 4 than a solution with a pH of 7? A: A solution with a pH of 4 is 1000 (10  10  10, or 103 ) times more acidic than a solution with a pH of 7. Q: Which solution on the pH scale in the Figure 1.1 is the weakest acid? Which solution is the strongest base? A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14. "
Which of the following chemical equations represents a neutralization reaction?,(A) NaOH + H2 O  OH + Na+ (B) Na+ + Cl  NaCl (C) HCl + NaOH  NaCl + H2 O (D) Mg + 2HCl  H2 + MgCl2,C,"When an acid and a base react, the reaction is called a neutralization reaction. Thats because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. Lets see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is: NaOH + HCl  H2 O and NaCl Now lets break this reaction down into two parts to see how each product forms. Positive hydrogen ions from HCl and negative hydroxide ions from NaOH combine to form water. This part of the reaction can be represented by the equation: H+ + OH  H2 O Positive sodium ions from NaOH and negative chloride ions from HCL combine to form the salt sodium chloride (NaCl), commonly called table salt. This part of the reaction can be represented by the equation: Na+ + Cl  NaCl Another example of a neutralization reaction can be seen in the Figure 1.1. Q: What products are produced when antacid tablets react with hydrochloric acid in the stomach? A: The products are water and the salt calcium chloride (CaCl2 ). Carbon dioxide (CO2 ) is also produced. The reaction is represented by the chemical equation: CaCO3 + 2HCl  H2 O + CaCl2 + CO2 "
The scientist who discovered radioactivity was,(A) Curie (B) Geiger (C) Becquerel (D) none of the above,C,"Radioactivity was discovered in 1896 by a French physicist named Antoine Henri Becquerel, who is pictured 1.1. Becquerel was experimenting with uranium, which was known to glow after being exposed to sunlight. Becquerel wanted to see if the glow was caused by rays of energy, like rays of light or X-rays. He placed a bit of uranium on a photographic plate after exposing the uranium to sunlight. The plate was similar to the film that is used today to take X-rays, and Becquerel expected the uranium to leave an image on the plate. The next day, there was an image on the plate, just as Becquerel expected. This meant that uranium gives off rays after being exposed to sunlight. Becquerel was a good scientist, so he wanted to repeat his experiment to confirm his results. He placed more uranium on another photographic plate. However, the day had turned cloudy, so he tucked the plate and uranium in a drawer to try again another day. He wasnt expecting the uranium to leave an image on the plate without first being exposed to sunlight. To his surprise, there was an image on the plate in the drawer the next day. Becquerel had discovered that uranium gives off rays of energy on its own. He had discovered radioactivity, for which he received a Nobel prize. Another scientist, who worked with Becquerel, actually came up with the term radioactivity. The other scientist was the French chemist Marie Curie. She went on to discover the radioactive elements polonium and radium. She won two Nobel Prizes for her discoveries. "
All nuclei that emit radiation are,(A) radioactive (B) very large (C) unstable (D) two of the above,D,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protonssuch as uranium, radium, and poloniumhave unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. "
The radioactive isotope of carbon is,(A) carbon-12 (B) carbon-13 (C) carbon-14 (D) none of the above,C,"Atoms need a certain ratio of neutrons to protons to have a stable nucleus. Having too many or too few neutrons relative to protons results in an unstable, or radioactive, nucleus that will sooner or later break down to a more stable form. This process is called radioactive decay. Many isotopes have radioactive nuclei, and these isotopes are referred to as radioisotopes. When they decay, they release particles that may be harmful. This is why radioactive isotopes are dangerous and why working with them requires special suits for protection. The isotope of carbon known as carbon-14 is an example of a radioisotope. In contrast, the carbon isotopes called carbon-12 and carbon-13 are stable. "
Which combination of protons and neutrons would most likely result in a stable nucleus?,(A) 4 protons and 2 neutrons (B) 4 protons and 4 neutrons (C) 4 protons and 6 neutrons (D) 4 protons and 8 neutrons,B,"All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactive. These isotopes are called radioisotopes. Their nuclei are unstable, so they break down, or decay, and emit radiation. Q: What makes the nucleus of a radioisotope unstable? A: The nucleus may be unstable because it has too many protons or an unstable ratio of protons to neutrons. For a nucleus with a small number of protons to be stable, the ratio of protons to neutrons should be 1:1. For a nucleus with a large number of protons to be stable, the ratio should be about 1:1.5. "
Rocks may release radiation due to,(A) formation of radioactive gas in the rocks (B) radioactive elements in the rocks (C) carbon-12 in the rocks (D) two of the above,D,A rock under enough stress will fracture. There may or may not be movement along the fracture. 
Some elements naturally change into different elements.,(A) true (B) false,A,"For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can one element change into another? A: The starting element must be radioactive, and its nuclei must gain or lose protons. "
Only unstable nuclei emit radiation.,(A) true (B) false,A,"Radioactive elements and isotopes have unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei give off, or emit, radiation in the form of energy and often particles as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. "
The radioactive isotope of carbon has fewer neutrons than other isotopes of carbon.,(A) true (B) false,B,"Isotopes are atoms of the same element that differ from each other because they have different numbers of neutrons. Many elements have one or more isotopes that are radioactive. Radioactive isotopes are called radioisotopes. An example of a radioisotope is carbon-14. All carbon atoms have 6 protons, and most have 6 neutrons. These carbon atoms are called carbon-12, where 12 is the mass number (6 protons + 6 neutrons). A tiny percentage of carbon atoms have 8 neutrons instead of the usual 6. These atoms are called carbon-14 (6 protons + 8 neutrons). The nuclei of carbon-14 are unstable because they have too many neutrons. To be stable, a small nucleus like carbon, with just 6 protons, must have a 1:1 ratio of protons to neutrons. In other words, it must have the same number of neutrons as protons. In a large nucleus, with many protons, the ratio must be 2:1 or even 3:1 protons to neutrons. In elements with more than 83 protons, all the isotopes are radioactive (see Figure 11.2). The force of repulsion among all those protons overcomes the strong force holding them together. This makes the nuclei unstable and radioactive. Elements with more than 92 protons have such unstable nuclei that these elements do not even exist in nature. They exist only if they are created in a lab. "
Radon gas is harmful when it burns and causes pollution.,(A) true (B) false,B,"One source of indoor air pollution is radon gas. Radon is a radioactive gas that may seep into buildings from rocks underground. Exposure to radon gas may cause lung cancer. Another potential poison in indoor air is carbon monoxide. It may be released by faulty or poorly vented furnaces or other fuel-burning appliances. Indoor furniture, carpets, and paints may release toxic compounds into the air as well. Other possible sources of indoor air pollution include dust, mold, and pet dander. "
Background radiation is generally considered to be safe for living things.,(A) true (B) false,A,"A low level of radiation occurs naturally in the environment. This is called background radiation. One source of background radiation is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. "
There is no way to detect radiation.,(A) true (B) false,B,"One reason radiation is dangerous is that it cant be detected with the senses. You normally cant see it, smell it, hear it, or feel it. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one in Figure 11.4, has a tube that contains atoms of a gas. If radiation enters the tube, it turns gas atoms to ions that carry electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation. You can see a video about the Geiger counter and how it was invented at the URL below. "
Radiation can break bonds in biochemical molecules.,(A) true (B) false,A,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
Radioactive isotopes can be used to determine the ages of fossils.,(A) true (B) false,A,Radioactive isotopes can be used to estimate the ages of fossils and rocks. The method is called radioactive dating. Carbon-14 dating is an example of radioactive dating. It is illustrated in the video at this URL:  MEDIA Click image to the left or use the URL below. URL: 
Radiation is harmless to nonliving things such as metals.,(A) true (B) false,B,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
You cannot see radiation but you can always feel it.,(A) true (B) false,B,"You generally cant see, smell, taste, hear, or feel radiation. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one pictured in the Figure 1.1, contains atoms of a gas that is ionized if it encounters radiation. When this happens, the gas atoms change to ions that can carry an electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation. "
A single large exposure to radiation can burn the skin.,(A) true (B) false,A,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
Human activities are responsible for almost all the radiation in the environment.,(A) true (B) false,B,Natural processes caused earlier climate changes. Human beings are the main cause of recent global warming. 
Radiation can be used to generate electricity.,(A) true (B) false,A,"Despite its dangers, radioactivity has several uses. For example, it can be used to determine the ages of ancient rocks and fossils. It can also be used as a source of power to generate electricity. Radioactivity can even be used to diagnose and treat diseases, including cancer. Cancer cells grow rapidly and take up a lot of glucose for energy. Glucose containing radioactive elements can be given to patients. Cancer cells take up more of the glucose than normal cells do and give off radiation. The radiation can be detected with special machines like the one in the Figure 1.2. The radiation may also kill cancer cells. "
Any exposure to radiation causes burns and destroys blood cells.,(A) true (B) false,B,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
A Geiger counter works because radiation changes atoms of a gas to ions.,(A) true (B) false,A,"You generally cant see, smell, taste, hear, or feel radiation. Fortunately, there are devices such as Geiger counters that can detect radiation. A Geiger counter, like the one pictured in the Figure 1.1, contains atoms of a gas that is ionized if it encounters radiation. When this happens, the gas atoms change to ions that can carry an electric current. The current causes the Geiger counter to click. The faster the clicks occur, the higher the level of radiation. "
radioactive gas that forms in rocks underground,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,D,"A low level of radiation occurs naturally in the environment. This is called background radiation. It comes from various sources. One source is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. A source of radiation that may be more dangerous is radon. Radon is a radioactive gas that forms in rocks underground. It can seep into basements and get trapped inside buildings. Then it may build up and become harmful to people who breathe it. Other sources of radiation are described in the interactive animation at this URL: http://w "
scientist who discovered radioactivity,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,F,"Radioactivity was discovered in 1896 by a French physicist named Antoine Henri Becquerel, who is pictured 1.1. Becquerel was experimenting with uranium, which was known to glow after being exposed to sunlight. Becquerel wanted to see if the glow was caused by rays of energy, like rays of light or X-rays. He placed a bit of uranium on a photographic plate after exposing the uranium to sunlight. The plate was similar to the film that is used today to take X-rays, and Becquerel expected the uranium to leave an image on the plate. The next day, there was an image on the plate, just as Becquerel expected. This meant that uranium gives off rays after being exposed to sunlight. Becquerel was a good scientist, so he wanted to repeat his experiment to confirm his results. He placed more uranium on another photographic plate. However, the day had turned cloudy, so he tucked the plate and uranium in a drawer to try again another day. He wasnt expecting the uranium to leave an image on the plate without first being exposed to sunlight. To his surprise, there was an image on the plate in the drawer the next day. Becquerel had discovered that uranium gives off rays of energy on its own. He had discovered radioactivity, for which he received a Nobel prize. Another scientist, who worked with Becquerel, actually came up with the term radioactivity. The other scientist was the French chemist Marie Curie. She went on to discover the radioactive elements polonium and radium. She won two Nobel Prizes for her discoveries. "
ability of an atomic nucleus to give off charged particles and energy,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,C,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from the nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. When they do, they gain or lose protons. Then the atoms become different elements. (Be careful not to confuse this radiation with electromagnetic radiation, which has to do with the light given off by atoms as they absorb and then emit energy.) "
low level of radiation that occurs naturally in the environment,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,B,"A low level of radiation occurs naturally in the environment. This is called background radiation. One source of background radiation is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. "
charged particles and energy emitted by an unstable nucleus,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,A,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protonssuch as uranium, radium, and poloniumhave unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. "
scientist who discovered polonium and radium,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,G,"Radioactivity was discovered in 1896 by a French physicist named Antoine Henri Becquerel, who is pictured 1.1. Becquerel was experimenting with uranium, which was known to glow after being exposed to sunlight. Becquerel wanted to see if the glow was caused by rays of energy, like rays of light or X-rays. He placed a bit of uranium on a photographic plate after exposing the uranium to sunlight. The plate was similar to the film that is used today to take X-rays, and Becquerel expected the uranium to leave an image on the plate. The next day, there was an image on the plate, just as Becquerel expected. This meant that uranium gives off rays after being exposed to sunlight. Becquerel was a good scientist, so he wanted to repeat his experiment to confirm his results. He placed more uranium on another photographic plate. However, the day had turned cloudy, so he tucked the plate and uranium in a drawer to try again another day. He wasnt expecting the uranium to leave an image on the plate without first being exposed to sunlight. To his surprise, there was an image on the plate in the drawer the next day. Becquerel had discovered that uranium gives off rays of energy on its own. He had discovered radioactivity, for which he received a Nobel prize. Another scientist, who worked with Becquerel, actually came up with the term radioactivity. The other scientist was the French chemist Marie Curie. She went on to discover the radioactive elements polonium and radium. She won two Nobel Prizes for her discoveries. "
atom with an unstable nucleus that emits radiation,(A) radiation (B) background radiation (C) radioactivity (D) radon (E) radioisotope (F) Antoine Becquerel (G) Marie Curie,E,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protonssuch as uranium, radium, and poloniumhave unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. "
"For an element to change to a different element, it must change its number of",(A) energy levels (B) electrons (C) neutrons (D) protons,D,"For an atom of one element to change into a different element, the number of protons in its nucleus must change. Thats because each element has a unique number of protons. For example, lead atoms always have 82 protons, and gold atoms always have 79 protons. Q: So how can one element change into another? A: The starting element must be radioactive, and its nuclei must gain or lose protons. "
Which statement about radioisotopes is false?,(A) Radioisotopes have unstable nuclei (B) Some elements exist only as radioisotopes (C) All elements have one or more radioisotopes (D) Radioisotopes contribute to background radiation,C,"Atoms need a certain ratio of neutrons to protons to have a stable nucleus. Having too many or too few neutrons relative to protons results in an unstable, or radioactive, nucleus that will sooner or later break down to a more stable form. This process is called radioactive decay. Many isotopes have radioactive nuclei, and these isotopes are referred to as radioisotopes. When they decay, they release particles that may be harmful. This is why radioactive isotopes are dangerous and why working with them requires special suits for protection. The isotope of carbon known as carbon-14 is an example of a radioisotope. In contrast, the carbon isotopes called carbon-12 and carbon-13 are stable. "
Radioactive elements include,(A) radium (B) uranium (C) polonium (D) all of the above,D,"Radioactive decay is the breakdown of unstable elements into stable elements. To understand this process, recall that the atoms of all elements contain the particles protons, neutrons, and electrons. "
Elements with more than 92 protons are,(A) a source of radiation in rocks (B) too unstable to exist in nature (C) the least radioactive elements (D) the only radioactive elements,B,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
Sources of background radiation include,(A) medical X rays (B) cosmic rays (C) nuclear power plants (D) all of the above,B,"A low level of radiation occurs naturally in the environment. This is called background radiation. One source of background radiation is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. "
Uranium can leave an image on a photographic plate because uranium,(A) gives off X rays (B) absorbs sunlight (C) emits light rays (D) is radioactive,D,"The Figure 1.2 shows how nuclear fission of uranium-235 occurs. It begins when a uranium nucleus gains a neutron. This can happen naturally when a free neutron strikes it, or it can occur deliberately when a neutron is crashed into it in a nuclear power plant. In either case, the nucleus of uranium-235 becomes extremely unstable with the extra neutron. As a result, it splits into two smaller nuclei, krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. It can be represented by this nuclear equation: 235 U 92 141 + 1 neutron  92 36 Kr + 56 Ba + 3 neutrons + energy Note that the subscripts of the element symbols represent numbers of protons and the superscripts represent numbers of protons plus neutrons. "
An alpha particle has the same mass as a helium nucleus.,(A) true (B) false,A,"Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equations by the symbol 4 He. 2 The superscript 4 is the mass number (2 protons + 2 neutrons). The subscript 2 is the charge of the particle as well as the number of protons. An example of alpha decay is the decay of uranium-238 to thorium-234. In this reaction, uranium loses two protons and two neutrons to become the element thorium. The reaction can be represented by this equation: 238 92 U 4 !234 90 Th +2 He + Energy If you count the number of protons and neutrons on each side of this equation, youll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can pick up two electrons to form the element helium. This is how most of Earths helium formed. Problem Solving ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 208 84 Po !? Pb +2 He + Energy Solution: The subscript is 82, and the superscript is 204. You Try It! ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 222 ? Ra !86 Rn+2 He+Energy "
How does a nucleus change when it undergoes beta decay?,(A) Its atomic number increases (B) Its mass number increases (C) It has more neutrons (D) It has fewer protons,A,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron. An electron is a negatively charged particle, and a positron is a positively charged electron (or anti- electron). When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay. Beta-minus decay occurs when a nucleus has too many neutrons relative to protons, and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons, so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay? A: Beta decay begins with a proton or neutron. You can see how in the Figure 1.1. Q: How does beta decay change an atom to a different element? A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton. In each case, the atom becomes a different element because it has a different number of protons. "
Nuclear equations do not need to balance.,(A) true (B) false,B,"Einsteins equation helps scientists understand what happens in nuclear reactions and why they produce so much energy. When the nucleus of a radioisotope undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass. What happens to the lost mass? It isnt really lost at all. It is converted to energy. How much energy? E = mc2 . The change in mass is tiny, but it results in a great deal of energy. Q: In a nuclear reaction, mass decreases and energy increases. What about the laws of conservation of mass and conservation of energy? Are mass and energy not conserved in nuclear reactions? Do we need to throw out these laws when it comes to nuclear reactions? A: No, the laws still apply. However, its more correct to say that the sum of mass and energy is always conserved in a nuclear reaction. Mass changes to energy, but the total amount of mass and energy combined remains the same. "
Which of the following nuclear equations represents alpha decay?,(A) 146 C 147 N +10 e + Energy (B) 210 (C) 92 U  90 Th +2 He + Energy (D) two of the above,C,"Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equations by the symbol 4 He. 2 The superscript 4 is the mass number (2 protons + 2 neutrons). The subscript 2 is the charge of the particle as well as the number of protons. An example of alpha decay is the decay of uranium-238 to thorium-234. In this reaction, uranium loses two protons and two neutrons to become the element thorium. The reaction can be represented by this equation: 238 92 U 4 !234 90 Th +2 He + Energy If you count the number of protons and neutrons on each side of this equation, youll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can pick up two electrons to form the element helium. This is how most of Earths helium formed. Problem Solving ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 208 84 Po !? Pb +2 He + Energy Solution: The subscript is 82, and the superscript is 204. You Try It! ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 222 ? Ra !86 Rn+2 He+Energy "
A beta particle has virtually no mass.,(A) true (B) false,A,"The nucleus of the atom is extremely small. Its radius is only about 1/100,000 of the total radius of the atom. If an atom were the size of a football stadium, the nucleus would be about the size of a pea! Click image to the left or use the URL below. URL:  Electrons have virtually no mass, but protons and neutrons have a lot of mass for their size. As a result, the nucleus has virtually all the mass of an atom. Given its great mass and tiny size, the nucleus is very dense. If an object the size of a penny had the same density as the nucleus of an atom, its mass would be greater than 30 million tons! Click image to the left or use the URL below. URL: "
"For a nuclear equation to be balanced, both sides of the equation must have the same number of",(A) protons (B) neutrons (C) electrons (D) protons plus neutrons,D,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
Charged particles are emitted from a nucleus during,(A) beta decay (B) alpha decay (C) gamma decay (D) two of the above,D,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from the nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. When they do, they gain or lose protons. Then the atoms become different elements. (Be careful not to confuse this radiation with electromagnetic radiation, which has to do with the light given off by atoms as they absorb and then emit energy.) "
Gamma rays are released only during gamma decay.,(A) true (B) false,B,"In alpha and beta decay, both particles and energy are emitted. In gamma decay, only energy is emitted. Gamma decay occurs when an unstable nucleus gives off gamma rays. Gamma rays, like rays of visible light and X-rays, are waves of energy that travel through space at the speed of light. Gamma rays have the greatest amount of energy of all such waves. By itself, gamma decay doesnt cause one element to change into another, but it is released in nuclear reactions that do. Some of the energy released in alpha and beta decay is in the form of gamma rays. You can learn more about gamma radiation at this URL:  (2:45). MEDIA Click image to the left or use the URL below. URL: "
Which of the following radioisotopes has the longest half-life?,(A) uranium-238 (B) carbon-14 (C) hydrogen-3 (D) radon-222,A,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
Alpha particles can pass through a sheet of aluminum.,(A) true (B) false,B,Beta particles can travel about a meter through air. They can pass through a sheet of paper or a layer of cloth but not through a sheet of aluminum or a few centimeters of wood. They can also penetrate the skin and damage underlying tissues. They are even more harmful if they are ingested or inhaled. 
Carbon-14 has a half-life of 5.7 million years.,(A) true (B) false,B,"Carbon-14 has a relatively short half-life (see Table 11.1). After about 50,000 years, too little carbon-14 is left in a fossil to be measured. Therefore, carbon-14 dating can only be used to date fossils that are less than 50,000 years old. Radioisotopes with a longer half-life, such as potassium-40, must be used to date older fossils and rocks. "
All three types of radioactive decay emit energy.,(A) true (B) false,A,"There are several types of radioactive decay, including alpha, beta, and gamma decay. In all three types, nuclei emit radiation, but the nature of the radiation differs. The Table 1.1 shows the radiation emitted in each type of decay. Type Alpha decay Beta decay Gamma decay Radiation Emitted alpha particle (2 protons and 2 neutrons) + energy beta particle (1 electron or 1 positron) + energy energy (gamma ray) "
A beta particle has a charge of +1.,(A) true (B) false,B,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is an electron. It has a charge of -1. In nuclear equations, a beta particle is represented by the symbol 01 e. The subscript -1 represents the particles charge, and the superscript 0 shows that the particle has virtually no mass. Nuclei contain only protons and neutrons, so how can a nucleus emit an electron? A neutron first breaks down into a proton and an electron (see Figure 11.7). Then the electron is emitted from the nucleus, while the proton stays inside the nucleus. The proton increases the atomic number by one, thus changing one element into another. An example of beta decay is the decay of thorium-234 to protactinium-234. In this reaction, thorium loses a neutron and gains a proton to become protactinium. The reaction can be represented by this equation: 234 90 Th !234 91 Pa + 0 1 e + Energy The protactinium-234 produced in this reaction is radioactive and decays to another element. The electron produced in the reaction (plus another electron) can combine with an alpha particle to form helium. Problem Solving Problem: Fill in the missing subscript and superscript in this nuclear equation: 131 I 53 !?? Xe + 14 C ? !?7 N + Solution: The subscript is 54, and the superscript is 131. 0 e + Energy 1 You Try It! Problem: Fill in the missing subscript and superscript in this nuclear equation: 0 e + Energy 1 "
"During beta decay, a proton is emitted by a nucleus.",(A) true (B) false,B,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron. An electron is a negatively charged particle, and a positron is a positively charged electron (or anti- electron). When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay. Beta-minus decay occurs when a nucleus has too many neutrons relative to protons, and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons, so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay? A: Beta decay begins with a proton or neutron. You can see how in the Figure 1.1. Q: How does beta decay change an atom to a different element? A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton. In each case, the atom becomes a different element because it has a different number of protons. "
All radioisotopes decay at the same constant rate.,(A) true (B) false,B,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
"In all three types of radioactive decay, nuclei emit energy.",(A) true (B) false,A,"Atoms with unstable nuclei are radioactive. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei emit energy and usually particles of matter as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. "
"During gamma decay, one element changes into another.",(A) true (B) false,B,"Gamma rays are produced when radioactive elements decay. Radioactive elements are elements with unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In this process, the nuclei give off energy and may also emit charged particles of matter. Types of radioactive decay include alpha, beta, and gamma decay. In alpha and beta decay, both particles and energy are emitted. In gamma decay, only energy, in the form of gamma rays, is emitted. Alpha and beta decay occur when a nucleus has too many protons or an unstable ratio of protons to neutrons. When the nucleus emits a particle, it gains or loses one or two protons, so the atom becomes a different element. Gamma decay, in contrast, occurs when a nucleus is in an excited state and has too much energy to be stable. This often happens after alpha or beta decay has occurred. Because only energy is emitted during gamma decay, the number of protons remains the same. Therefore, an atom does not become a different element during this type of decay. Q: The Figure 1.1 shows how helium-3 (He-3) decays by emitting a gamma particle. How can you tell that the atom is still the same element after gamma decay occurs? A: The nucleus of the atom has two protons (red) before the reaction occurs. After the nucleus emits the gamma particle, it still has two protons, so the atom is still the same element. "
Most of Earths helium formed when alpha particles picked up electrons.,(A) true (B) false,A,"In the first few moments after the Big Bang, the universe was extremely hot and dense. As the universe expanded, it became less dense. It began to cool. First protons, neutrons, and electrons formed. From these particles came hydrogen. Nuclear fusion created helium atoms. Some parts of the universe had matter that was densely packed. Enormous clumps of matter were held together by gravity. Eventually this material became the gas clouds, stars, galaxies, and other structures that we see in the universe today. "
Carbon-14 forms when cosmic rays strike atoms of carbon-12.,(A) true (B) false,B,"Carbon-14 forms naturally in Earths atmosphere when cosmic rays strike atoms of nitrogen-14. Living things take in and use carbon-14, just as they do carbon-12. The carbon-14 in living things gradually decays to nitrogen-14. However, it is constantly replaced because living things keep taking in carbon-14. As a result, there is a fixed ratio of carbon-14 to carbon-12 in organisms as long as they are alive. This is illustrated in the top part of Figure 11.10. After organisms die, the carbon-14 they already contain continues to decay, but it is no longer replaced (see bottom part of Figure 11.10). Therefore, the carbon-14 in a dead organism constantly declines at a fixed rate equal to the half-life of carbon-14. Half of the remaining carbon-14 decays every 5,730 years. If you measure how much carbon- 14 is left in a fossil, you can determine how many half-lives (and how many years) have passed since the organism died. "
Carbon-14 dating can be used to estimate the age of any fossil.,(A) true (B) false,B,"Carbon-14 has a relatively short half-life (see Table 11.1). After about 50,000 years, too little carbon-14 is left in a fossil to be measured. Therefore, carbon-14 dating can only be used to date fossils that are less than 50,000 years old. Radioisotopes with a longer half-life, such as potassium-40, must be used to date older fossils and rocks. "
method of aging fossils that uses radioisotopes,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,C,The rate of decay of unstable isotopes can be used to estimate the absolute ages of fossils and rocks. This type of dating is called radiometric dating. 
process in which unstable nuclei emit charged particles and energy,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,F,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protonssuch as uranium, radium, and poloniumhave unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. "
process in which a radioactive nucleus emits only energy,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,E,"Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radioactive decay is a nuclearrather than chemicalreaction because it involves only the nuclei of atoms. In a nuclear reaction, one element may change into another. Click image to the left or use the URL below. URL: "
form of energy emitted during radioactive decay,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,G,"Radioactive elements and isotopes have unstable nuclei. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei give off, or emit, radiation in the form of energy and often particles as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. "
particle consisting of two protons and two neutrons,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,B,"A neutron is a particle inside the nucleus of an atom. It has no electric charge. Atoms of an element often have the same number of neutrons as protons. For example, most carbon atoms have six neutrons as well as six protons. This is also shown in Figure below . "
rate at which a radioactive isotope decays,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,A,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
electron emitted by an unstable nucleus,(A) half-life (B) alpha particle (C) radioactive dating (D) beta particle (E) gamma decay (F) radioactive decay (G) gamma ray,D,"Atoms with unstable nuclei are radioactive. To become more stable, the nuclei undergo radioactive decay. In radioactive decay, the nuclei emit energy and usually particles of matter as well. There are several types of radioactive decay, including alpha, beta, and gamma decay. Energy is emitted in all three types of decay, but only alpha and beta decay also emit particles. "
Unstable nuclei of radioisotopes may become stable by,(A) undergoing radioactive decay (B) changing into other elements (C) emitting particles and energy (D) all of the above,D,"Atoms need a certain ratio of neutrons to protons to have a stable nucleus. Having too many or too few neutrons relative to protons results in an unstable, or radioactive, nucleus that will sooner or later break down to a more stable form. This process is called radioactive decay. Many isotopes have radioactive nuclei, and these isotopes are referred to as radioisotopes. When they decay, they release particles that may be harmful. This is why radioactive isotopes are dangerous and why working with them requires special suits for protection. The isotope of carbon known as carbon-14 is an example of a radioisotope. In contrast, the carbon isotopes called carbon-12 and carbon-13 are stable. "
Which of the following equations represents alpha decay?,(A) 146 C  147 N + 10 e + Energy (B) 222 (C) 53 I  54 Xe + 1 e + Energy (D) none of the above,B,"Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equations by the symbol 4 He. 2 The superscript 4 is the mass number (2 protons + 2 neutrons). The subscript 2 is the charge of the particle as well as the number of protons. An example of alpha decay is the decay of uranium-238 to thorium-234. In this reaction, uranium loses two protons and two neutrons to become the element thorium. The reaction can be represented by this equation: 238 92 U 4 !234 90 Th +2 He + Energy If you count the number of protons and neutrons on each side of this equation, youll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can pick up two electrons to form the element helium. This is how most of Earths helium formed. Problem Solving ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 208 84 Po !? Pb +2 He + Energy Solution: The subscript is 82, and the superscript is 204. You Try It! ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 222 ? Ra !86 Rn+2 He+Energy "
Examples of beta decay include,(A) 238 (B) 234 (C) 106 Sg  104 Rf + 2 He + Energy (D) two of the above,D,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is an electron. It has a charge of -1. In nuclear equations, a beta particle is represented by the symbol 01 e. The subscript -1 represents the particles charge, and the superscript 0 shows that the particle has virtually no mass. Nuclei contain only protons and neutrons, so how can a nucleus emit an electron? A neutron first breaks down into a proton and an electron (see Figure 11.7). Then the electron is emitted from the nucleus, while the proton stays inside the nucleus. The proton increases the atomic number by one, thus changing one element into another. An example of beta decay is the decay of thorium-234 to protactinium-234. In this reaction, thorium loses a neutron and gains a proton to become protactinium. The reaction can be represented by this equation: 234 90 Th !234 91 Pa + 0 1 e + Energy The protactinium-234 produced in this reaction is radioactive and decays to another element. The electron produced in the reaction (plus another electron) can combine with an alpha particle to form helium. Problem Solving Problem: Fill in the missing subscript and superscript in this nuclear equation: 131 I 53 !?? Xe + 14 C ? !?7 N + Solution: The subscript is 54, and the superscript is 131. 0 e + Energy 1 You Try It! Problem: Fill in the missing subscript and superscript in this nuclear equation: 0 e + Energy 1 "
Which of the following radioisotopes has the shortest half-life?,(A) uranium-238 (B) potassium-40 (C) carbon-14 (D) polonium-214,B,"A radioactive isotope decays at a certain constant rate. The rate is measured in a unit called the half-life. This is the length of time it takes for half of a given amount of the isotope to decay. The concept of half-life is illustrated in Figure 11.9 for the beta decay of phosphorus-32 to sulfur-32. The half-life of this radioisotope is 14 days. After 14 days, half of the original amount of phosphorus-32 has decayed. After another 14 days, half of the remaining amount (or one-quarter of the original amount) has decayed, and so on. Different radioactive isotopes vary greatly in their rate of decay. As you can see from the examples in Table 11.1, the half-life of a radioisotope can be as short as a split second or as long as several billion years. You can simulate radioactive decay of radioisotopes with different half-lives at the URL below. Some radioisotopes decay much more quickly than others. Isotope Uranium-238 Potassium-40 Carbon-14 Hydrogen-3 Radon-222 Polonium-214 Half-life 4.47 billion years 1.28 billion years 5,730 years 12.3 years 3.82 days 0.00016 seconds Problem Solving Problem: If you had a gram of carbon-14, how many years would it take for radioactive decay to reduce it to one-quarter of a gram? Solution: One gram would decay to one-quarter of a gram in 2 half-lives years. 1 2 12 = 1 4 , or 2  5,730 years = 11,460 You Try It! Problem: What fraction of a given amount of hydrogen-3 would be left after 36.9 years of decay? "
Beta particles can travel,(A) only a few centimeters through air (B) up to a meter through air (C) through several meters of concrete (D) for thousands of meters through air,C,Beta particles can travel about a meter through air. They can pass through a sheet of paper or a layer of cloth but not through a sheet of aluminum or a few centimeters of wood. They can also penetrate the skin and damage underlying tissues. They are even more harmful if they are ingested or inhaled. 
Which type of radiation is most harmful to living things?,(A) alpha particles (B) beta particles (C) gamma rays (D) X rays,D,Gamma rays are the most dangerous type of radiation. They can travel farther and penetrate materials more deeply than can the charged particles emitted during alpha and beta decay. Gamma rays can be stopped only by several centimeters of lead or several meters of concrete. Its no surprise that they can penetrate and damage cells deep inside the body. 
An alpha particle has a charge of,(A) 0 (B) -1 (C) +1 (D) +2,A,"Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equations by the symbol 4 He. 2 The superscript 4 is the mass number (2 protons + 2 neutrons). The subscript 2 is the charge of the particle as well as the number of protons. An example of alpha decay is the decay of uranium-238 to thorium-234. In this reaction, uranium loses two protons and two neutrons to become the element thorium. The reaction can be represented by this equation: 238 92 U 4 !234 90 Th +2 He + Energy If you count the number of protons and neutrons on each side of this equation, youll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can pick up two electrons to form the element helium. This is how most of Earths helium formed. Problem Solving ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 208 84 Po !? Pb +2 He + Energy Solution: The subscript is 82, and the superscript is 204. You Try It! ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 222 ? Ra !86 Rn+2 He+Energy "
Which equation represents a nuclear fusion reaction?,(A) 60 (B) 1 H + 1 H  42 He + 1 Neutron + Energy (C) 238 (D) 92 U + 1 Neutron  92,B,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
A nuclear fission reaction occurs when a nucleus absorbs,(A) a proton (B) radiation (C) a neutron (D) light energy,C,"Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. For example, nuclear fission of a tiny pellet of uranium-235, like the one pictured in Figure 11.11, can release as much energy as burning 1,000 kilograms of coal! Nuclear fission of uranium-235 can be represented by this equation: 235 92 U + 1 141 Neutron !92 36 Kr + 56 Ba + 3 Neutrons + Energy As shown in Figure 11.12, the reaction begins when a nucleus of uranium-235 absorbs a neutron. This can happen naturally or when a neutron is deliberately crashed into a uranium nucleus in a nuclear power plant. In either case, the nucleus of uranium becomes very unstable and splits in two. In this example, it forms krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. "
Which of the following is a drawback of using nuclear fission for energy?,(A) It adds carbon to the atmosphere (B) It produces radioactive waste (C) It releases very little energy (D) two of the above,B,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: "
"If a successful nuclear fusion reactor could be built, the fuel it would use would be",(A) water (B) helium (C) uranium (D) hydrogen,D,"Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioiso- topes, nuclear fusion involves hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the worlds people for a very long time. Unfortunately, using energy from nuclear fusion is far from a reality. Scientists are a long way from developing the necessary technology. One problem is raising temperatures high enough for fusion to take place. Another problem is that matter this hot exists only in the plasma state. There are no known materials that can contain plasma, although a magnet might be able to do it. Thats because plasma consists of ions and responds to magnetism. You can learn more about research on nuclear fusion at the URL below. "
Which statement describes a way that matter and energy are related?,(A) Matter and energy are two forms of the same thing (B) Matter can be converted to energy in chemical reactions (C) A large amount of matter contains a small amount of energy (D) all of the above,A,"Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. "
E = mc2 explains why a small amount of mass can produce a great deal of energy.,(A) true (B) false,A,"Probably the most famous equation in the world is E = mc2 . You may have heard of it. You may have even seen it on a tee shirt or coffee mug. Its a simple equation that was derived in 1905 by the physicist Albert Einstein (see Figure 11.18). Although the equation is simple, it is incredibly important. It changed how scientists view two of the most basic concepts in science: matter and energy. The equation shows that matter and energy are two forms of the same thing. It also shows how matter and energy are related. In addition, Einsteins equation explains why nuclear fission and nuclear fusion produce so much energy. You can listen to a recording of Einstein explaining his famous equation at this URL: "
The letter c in the equation E = mc2 stands for chain reaction.,(A) true (B) false,B,"Einsteins equation is possibly the best-known equation of all time. Theres reason for that. The equation is incredibly important. It changed how scientists view energy and matter, which are two of the most basic concepts in all of science. The equation shows that energy and matter are two forms of the same thing. This new idea turned science upside down when Einstein introduced it in the early 1900s. Amazingly, the idea has withstood the test of time as more and more evidence has been gathered to support it. You can listen to an explanation of Einsteins equation at URL: https://youtu.be/hW7DW9NIO9M Q: What do the letters in Einsteins equation stand for? A: E stands for energy, m stands for mass, and c stands for the speed of light. The speed of light is 300,000 kilometers (186,000 miles) per second, so c2 is a very big number. Therefore, the amount of energy in even a small mass of matter is tremendous. Suppose, for example, that you have 1 gram of matter. Thats about the mass of a paperclip. Multiplying this mass by c2 would yield enough energy to power 3,600 homes for a year! "
The sum of mass and energy is conserved in nuclear reactions.,(A) true (B) false,A,"When the nucleus of a radioisotope undergoes fission or fusion, it loses a tiny amount of mass. What happens to the lost mass? It isnt really lost at all. It is converted to energy. How much energy? E = mc2 . The change in mass is tiny, but it results in a great deal of energy. What about the laws of conservation of mass and conservation of energy? Do they not apply to nuclear reactions? We dont need to throw out these laws. Instead, we just need to combine them. It is more correct to say that the sum of mass and energy is always conserved in a nuclear reaction. Mass may change to energy, but the amount of mass and energy combined remains the same. "
Nuclear fusion is the opposite of nuclear fission.,(A) true (B) false,A,"Nuclear fusion is the opposite of nuclear fission. In fusion, two or more small nuclei combine to form a single, larger nucleus. An example is shown in Figure 11.15. In this example, two hydrogen nuclei fuse to form a helium nucleus. A neutron and a great deal of energy are also released. In fact, fusion releases even more energy than fission does. "
Nuclear fission happens only in nuclear power plants.,(A) true (B) false,B,"Nuclear power plants use uranium that has been concentrated in fuel rods (Figure 5.6). The uranium atoms are split apart when they are hit by other extremely tiny particles. These particles must be controlled or they would cause a dangerous explosion. Nuclear power plants use the energy they produce to heat water. The water turns into steam, which causes a turbine to spin. This in turn produces electricity. "
An atom bomb explosion is an uncontrolled nuclear chain reaction,(A) true (B) false,A,"If a nuclear chain reaction is uncontrolled, it produces a lot of energy all at once. This is what happens in an atomic bomb. If a nuclear chain reaction is controlled, it produces energy more slowly. This is what occurs in a nuclear power plant. The reaction may be controlled by inserting rods of material that do not undergo fission into the core of fissioning material (see Figure 11.14). The radiation from the controlled fission is used to heat water and turn it to steam. The steam is under pressure and causes a turbine to spin. The spinning turbine runs a generator, which produces electricity. "
Using nuclear fission for power contributes to global warming.,(A) true (B) false,B,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: "
Nuclear fusion releases less energy than nuclear fission does.,(A) true (B) false,B,"Nuclear fusion is the opposite of nuclear fission. In fusion, two or more small nuclei combine to form a single, larger nucleus. An example is shown in Figure 11.15. In this example, two hydrogen nuclei fuse to form a helium nucleus. A neutron and a great deal of energy are also released. In fact, fusion releases even more energy than fission does. "
Waste from nuclear fission is no longer harmful after a couple of years.,(A) true (B) false,B,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: "
The suns energy comes from nuclear fusion in its core.,(A) true (B) false,A,"The Sun is Earths major source of energy, yet the planet only receives a small portion of its energy. The Sun is just an ordinary star. Many stars produce much more energy than the Sun. The energy source for all stars is nuclear fusion. "
"In the U.S., most electrical energy is produced in nuclear power plants.",(A) true (B) false,B,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
The fuel needed for nuclear fission is very plentiful.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
The use of nuclear fusion for energy involves dangerous isotopes.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Matter that undergoes nuclear fusion is in the plasma state.,(A) true (B) false,A,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
One product of a nuclear fusion reaction is a proton.,(A) true (B) false,B,"A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67  1027 kilograms. Together with neutrons, they make up virtually all of the mass of an atom. Click image to the left or use the URL below. URL:  Q: How do you think the sun is related to protons? A: The suns tremendous energy is the result of proton interactions. In the sun, as well as in other stars, protons from hydrogen atoms combine, or fuse, to form nuclei of helium atoms. This fusion reaction releases a huge amount of energy and takes place in nature only at the extremely high temperatures of stars such as the sun. "
Both nuclear fission and nuclear fusion,(A) are used for energy in electric power plants (B) release a huge amount of energy (C) cannot yet be controlled (D) produce three neutrons,B,"Nuclear fusion is the opposite of nuclear fission. In fusion, two or more small nuclei combine to form a single, larger nucleus. An example is shown in Figure 11.15. In this example, two hydrogen nuclei fuse to form a helium nucleus. A neutron and a great deal of energy are also released. In fact, fusion releases even more energy than fission does. "
Which equation represents a nuclear fission reaction?,(A) 60 (B) 1 H + 1 H  42 He + 1 Neutron + Energy (C) 238 (D) 92 U + 1 Neutron  92,D,"Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. For example, nuclear fission of a tiny pellet of uranium-235, like the one pictured in Figure 11.11, can release as much energy as burning 1,000 kilograms of coal! Nuclear fission of uranium-235 can be represented by this equation: 235 92 U + 1 141 Neutron !92 36 Kr + 56 Ba + 3 Neutrons + Energy As shown in Figure 11.12, the reaction begins when a nucleus of uranium-235 absorbs a neutron. This can happen naturally or when a neutron is deliberately crashed into a uranium nucleus in a nuclear power plant. In either case, the nucleus of uranium becomes very unstable and splits in two. In this example, it forms krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. "
"In a nuclear chain reaction, each fission reaction can lead directly to",(A) four more fission reactions (B) three more fission reactions (C) two more fission reactions (D) one more fission reaction,B,"The neutrons released in this nuclear fission reaction may be captured by other uranium nuclei and cause them to fission as well. This can start a nuclear chain reaction (see Figure 11.13). In a chain reaction, one fission reaction leads to others, which lead to others, and so on. A nuclear chain reaction is similar to a pile of wood burning. If you start one piece of wood burning, enough heat is produced by the burning wood to start the rest of the pile burning without any further help from you. You can see another example of a chain reaction at this URL: "
"In a nuclear power plant, nuclear reactions are controlled by inserting rods made of a material that",(A) cools down the fuel (B) makes the fuel stop burning (C) does not undergo fission (D) generates electric current,C,"If a nuclear chain reaction is uncontrolled, it produces a lot of energy all at once. This is what happens in an atomic bomb. However, if a nuclear chain reaction is controlled, it produces energy much more slowly. This is what occurs in a nuclear power plant. The reaction is controlled by inserting rods of nonfissioning material into the fissioning material. You can see this in the Figure 1.4. The radiation from the controlled fission is used to heat water and turn it to steam. The steam is under pressure and causes a turbine to spin. The spinning turbine runs a generator, which produces electricity. "
Which of the following is an advantage of nuclear fission over the burning of fossil fuels?,(A) Nuclear fission uses renewable resources (B) Nuclear fission produces no air pollution (C) Nuclear fission produces no wastes (D) Nuclear fission has no risks,B,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: "
"When tritium and deuterium fuse together, they form a nucleus of",(A) hydrogen (B) uranium (C) helium (D) barium,C,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
Which of the following is a problem in using nuclear fusion for energy?,(A) It produces dangerous nuclear wastes (B) It requires very high temperatures to occur (C) It depends on a very limited supply of fuel (D) all of the above,A,"Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioiso- topes, nuclear fusion involves hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the worlds people for a very long time. Unfortunately, using energy from nuclear fusion is far from a reality. Scientists are a long way from developing the necessary technology. One problem is raising temperatures high enough for fusion to take place. Another problem is that matter this hot exists only in the plasma state. There are no known materials that can contain plasma, although a magnet might be able to do it. Thats because plasma consists of ions and responds to magnetism. You can learn more about research on nuclear fusion at the URL below. "
process in which one nuclear reaction leads to others,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,C,"The neutrons released in this nuclear fission reaction may be captured by other uranium nuclei and cause them to fission as well. This can start a nuclear chain reaction (see Figure 11.13). In a chain reaction, one fission reaction leads to others, which lead to others, and so on. A nuclear chain reaction is similar to a pile of wood burning. If you start one piece of wood burning, enough heat is produced by the burning wood to start the rest of the pile burning without any further help from you. You can see another example of a chain reaction at this URL: "
splitting of a nucleus into two smaller nuclei,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,D,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
particle that starts a nuclear fission reaction,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,E,"Nuclear fission is the splitting of the nucleus of a radioactive atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. Fission of a tiny pellet of radioactive uranium- 235, like the one pictured in the Figure 1.1, releases as much energy as burning 1,000 kilograms of coal! Q: What causes the nucleus of uranium-235 atom to fission? A: Another particle collides with it. "
form of energy generated by a nuclear power plant,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,A,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
joining of two or more nuclei to form one larger nucleus,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,G,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
reaction such as nuclear fission or nuclear fusion,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,B,"Nuclear fission is the splitting of the nucleus of an atom into two smaller nuclei. This type of reaction releases a great deal of energy from a very small amount of matter. For example, nuclear fission of a tiny pellet of uranium-235, like the one pictured in Figure 11.11, can release as much energy as burning 1,000 kilograms of coal! Nuclear fission of uranium-235 can be represented by this equation: 235 92 U + 1 141 Neutron !92 36 Kr + 56 Ba + 3 Neutrons + Energy As shown in Figure 11.12, the reaction begins when a nucleus of uranium-235 absorbs a neutron. This can happen naturally or when a neutron is deliberately crashed into a uranium nucleus in a nuclear power plant. In either case, the nucleus of uranium becomes very unstable and splits in two. In this example, it forms krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. "
form of energy released in a nuclear reaction,(A) electrical energy (B) nuclear reaction (C) nuclear chain reaction (D) nuclear fission (E) neutron (F) nuclear energy (G) nuclear fusion,F,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
"If motion is represented by an arrow, what does the head of the arrow show?",(A) speed (B) position (C) distance (D) direction,D,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
something that is not moving with respect to an observer that can be used to detect motion,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,B,"Theres more to motion than objects simply changing position. Youll see why when you consider the following example. Assume that the school bus pictured in the Figure 1.2 passes by you as you stand on the sidewalk. Its obvious to you that the bus is moving, but what about to the children inside the bus? The bus isnt moving relative to them, and if they look at the other children sitting on the bus, they wont appear to be moving either. If the ride is really smooth, the children may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. Q: What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell that the bus is moving? A: Your frame of reference might be the trees and other stationary objects across the street. As the bus goes by, it momentarily blocks your view of these objects, and this helps you detect the bus motion. "
quantity that includes both size and direction,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,D,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"If you were riding in a car down a city street, which frame of reference would not allow you to detect that the car was moving?",(A) the driver of the car (B) buildings along the street (C) traffic lights at intersections (D) cars parked on the sides of the street,A,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
What SI unit would be most appropriate for measuring the distance between Earth and the moon?,(A) kilometer (B) meter (C) yard (D) mile,A,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
location,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,G,"To describe your location wherever you are on Earths surface, you could use a coordinate system. For example, you could say that you are at 1234 Main Street, Springfield, Ohio. Or you could use a point of reference. If you want to meet up with a friend, you could tell him the distance and direction you are from the reference point. An example is, I am at the corner of Maple Street and Main Street, about two blocks north of your apartment. When studying Earths surface, scientists must be able to pinpoint a feature they are interested in. Scientists and others have a system to describe the location of any feature. Usually they use latitude and longitude as a coordinate system. Lines of latitude and longitude form a grid. The grid is centered on a reference point. You will learn about this type of grid when we discuss maps later in this chapter. "
change in position,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,C,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
Which word could be used to describe the direction of a moving object?,(A) far (B) fast (C) forever (D) forward,D,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
line along which something moves,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,F,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
Frame of reference is,(A) something that affects perception of motion (B) a way to represent distance and direction (C) the line along which something moves (D) any change of location,A,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
length of the route between two points,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,A,"Distance is the length of the route between two points. The distance of a race, for example, is the length of the track between the starting and finishing lines. In a 100-meter sprint, that distance is 100 meters. "
SI unit for distance,(A) distance (B) frame of reference (C) motion (D) vector (E) meter (F) direction (G) position,E,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
Direction is as important as distance in describing motion.,(A) true (B) false,A,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
Most foot races are measured in meters.,(A) true (B) false,A,"Did you ever go to a track meet like the one pictured in Figure 12.3? Running events in track include 100-meter sprints and 2000-meter races. Races are named for their distance. Distance is the length of the route between two points. The length of the route in a race is the distance between the starting and finishing lines. In a 100-meter sprint, for example, the distance is 100 meters. "
Motion is generally defined as an increase in distance.,(A) true (B) false,B,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
Direction is the length of the route between two points.,(A) true (B) false,B,"Distance is the length of the route between two points. The distance of a race, for example, is the length of the track between the starting and finishing lines. In a 100-meter sprint, that distance is 100 meters. "
Short distances may be measured in centimeters.,(A) true (B) false,A,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
You can use a map to measure the distance between two points.,(A) true (B) false,A,Maps can often be used to measure distance. Look at the map in Figure 12.4. Find Mias house and the school. You can use the map key to directly measure the distance between these two points. The distance is 2 kilometers. Measure it yourself to see if you agree. 
A vector is any quantity that has no units of measurement.,(A) true (B) false,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
You can measure the distance an object travels only if it does not change direction.,(A) true (B) false,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
Motion is a vector when it includes only direction.,(A) true (B) false,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
You could measure distances with a metric ruler.,(A) true (B) false,A,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
Speed is one way to measure motion.,(A) true (B) false,A,"Speed is an important aspect of motion. It is a measure of how fast or slow something moves. It depends on how far something travels and how long it takes to travel that far. Speed can be calculated using this general formula: speed = distance time A familiar example is the speed of a car. In the U.S., this is usually expressed in miles per hour (see Figure 12.6). If your family makes a car trip that covers 120 miles and takes 3 hours, then the cars speed is: speed = 120 mi = 40 mi/h 3h The speed of a car may also be expressed in kilometers per hour (km/h). The SI unit for speed is meters per second (m/s). "
The length of a vector arrow represents direction.,(A) true (B) false,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"Words that describe direction include east, up, and left.",(A) true (B) false,A,"Direction can be described in relative terms, such as up, down, in, out, left, right, forward, backward, or sideways. Direction can also be described with the cardinal directions: north, south, east, or west. On maps, cardinal directions are indicated with a compass rose. You can see one in the bottom left corner of the map in the Figure 1.1. You can use the compass rose to find directions on the map. For example, to go to the school from Jordans house, you would travel from east to west. If you wanted to go on to the post office, you would change direction at the school and then travel from south to north. "
"If you were riding on a moving bus, which frame of reference would allow you to detect the motion?",(A) other people sitting on the bus (B) trees outside the bus windows (C) the seats on the bus (D) the bus driver,B,"Theres more to motion than objects simply changing position. Youll see why when you consider the following example. Assume that the school bus pictured in the Figure 1.2 passes by you as you stand on the sidewalk. Its obvious to you that the bus is moving, but what about to the children inside the bus? The bus isnt moving relative to them, and if they look at the other children sitting on the bus, they wont appear to be moving either. If the ride is really smooth, the children may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. Q: What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell that the bus is moving? A: Your frame of reference might be the trees and other stationary objects across the street. As the bus goes by, it momentarily blocks your view of these objects, and this helps you detect the bus motion. "
Which units would most likely be used to measure the distance between two cities?,(A) millimeters (B) centimeters (C) meters (D) kilometers,D,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
"To find the distance of a route that changes direction, you must",(A) consider only the distance traveled in the first direction (B) calculate the average distance traveled in one direction (C) add up all the distances traveled in different directions (D) subtract the starting distance from the ending distance,C,"Things dont always move in straight lines like the route from Mias house to the school. Sometimes they change direction as they move. For example, the route from Mias house to the post office changes from west to north at the school (see Figure 12.4). To find the total distance of a route that changes direction, you must add up the distances traveled in each direction. From Mias house to the school, for example, the distance is 2 kilometers. From the school to the post office, the distance is 1 kilometer. Therefore, the total distance from Mias house to the post office is 3 kilometers. You Try It! Problem: What is the distance from the post office to the park in Figure 12.4? Direction is just as important as distance in describing motion. For example, if Mia told a friend how to reach the post office from her house, she couldnt just say, ""go 3 kilometers."" The friend might end up at the park instead of the post office. Mia would have to be more specific. She could say, ""go west for 2 kilometers and then go north for 1 kilometer."" When both distance and direction are considered, motion is a vector. A vector is a quantity that includes both size and direction. A vector is represented by an arrow. The length of the arrow represents distance. The way the arrow points shows direction. The red arrows in Figure 12.4 are vectors for Mias route to the school and post office. If you want to learn more about vectors, watch the videos at these URLs:  (5:27) MEDIA Click image to the left or use the URL below. URL:  You Try It! Problem: Draw vectors to represent the route from the post office to the park in Figure 12.4. "
"When both distance and direction are considered, motion",(A) is always measured in meters (B) cannot be calculated (C) is a force of nature (D) is a vector,D,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"To determine the distance between two points on a map, you can use a ruler and",(A) a compass (B) the compass rose (C) a sheet of graph paper (D) the scale in the map key,D,Maps can often be used to measure distance. Look at the map in Figure 12.4. Find Mias house and the school. You can use the map key to directly measure the distance between these two points. The distance is 2 kilometers. Measure it yourself to see if you agree. 
"To explain how to get from point A to point B, you must describe both the distance and the",(A) speed (B) length (C) mileage (D) direction,D,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"When calculating average speed, the symbol d represents the",(A) change in distance (B) change in direction (C) instantaneous distance (D) division of distance by time,A,"In a distance-time graph, the speed of the object is represented by the slope, or steepness, of the graph line. If the line is straight, like the line between A and B in Figure 12.8, then the speed is constant. The average speed can be calculated from the graph. The change in distance (represented by Dd) divided by the change in time (represented by Dt): speed = Dd Dt For example, the speed between A and B in Figure 12.8 is: speed = Dd 20 km 0 km 20 km = = = 20 km/h Dt 8:30 7:30 h 1h If the graph line is horizontal, as it is between B and C, then the slope and the speed are zero: speed = Dd 20 km 20 km 0 km = = = 0 km/h Dt 9:00 8:30 h 0.5 h You Try It! Problem: In Figure 12.8, calculate the speed of the rider between C and D. "
Speed depends on how far something travels and,(A) how steep its route is (B) which direction it travels (C) how much time it takes to travel that far (D) none of the above,C,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
"If you run a 100-meter race in 20 seconds, what is your average speed during the race?",(A) 20 m/s (B) 10 m/s (C) 5 m/s (D) 2 m/s,C,"Did you ever go to a track meet like the one pictured in Figure 12.3? Running events in track include 100-meter sprints and 2000-meter races. Races are named for their distance. Distance is the length of the route between two points. The length of the route in a race is the distance between the starting and finishing lines. In a 100-meter sprint, for example, the distance is 100 meters. "
What is the SI unit for speed?,(A) s (B) m (C) m/s (D) s/m,C,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
Tony ran at a constant speed of 10 m/s for a total of 60 seconds. How far did he run?,(A) 6m (B) 60 m (C) 600 m (D) 6000 m,C,"If you know the speed of a moving object, you can also calculate the distance it will travel in a given amount of time. To do so, you would use this version of the general speed formula: distance = speed  time For example, if a car travels at a speed of 60 km/h for 2 hours, then the distance traveled is: distance = 60 km/h  2 h = 120 km You Try It! Problem: If Maria runs at a speed of 2 m/s, how far will she run in 60 seconds? "
"If the slope of a distance-time graph is steep, then the speed of the object must be",(A) slow (B) rapid (C) constant (D) changing,B,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
"If you travel 500 kilometers in 5 hours, your average speed is",(A) 5 km/h (B) 50 km/h (C) 100 km/h (D) 250 km/h,C,"Even if speed varies during the course of a trip, its easy to calculate the average speed by using this formula: speed = distance time For example, assume you go on a car trip with your family. The total distance you travel is 120 miles, and it takes 3 hours to travel that far. The average speed for the trip is: 120 mi 3h = 40 mi/h speed = Q: Terri rode her bike very slowly to the top of a big hill. Then she coasted back down the hill at a much faster speed. The distance from the bottom to the top of the hill is 3 kilometers. It took Terri 41 hour to make the round trip. What was her average speed for the entire trip? (Hint: The round-trip distance is 6 km.) A: Terris speed can be calculated as follows: 6 km 0.25 h = 24 km/h speed = "
"If you use an arrow to represent velocity, what does the length of the arrow represent?",(A) time (B) speed (C) distance (D) direction,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
Which choice(s) could represent the velocity of a moving car?,(A) 80 mi/h (B) 40 km/h (C) 50 km/h north (D) all of the above,C,The arrows in the Figure 1.1 represent the velocity of three different objects. Arrows A and B are the same length but point in different directions. They represent objects moving at the same speed but in different directions. Arrow C is shorter than arrow A or B but points in the same direction as arrow A. It represents an object moving at a slower speed than A or B but in the same direction as A. 
Objects moving at the same velocity have the same,(A) size (B) speed (C) direction (D) two of the above,D,"Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities. Look again at arrows A and B from the Figure 1.1. They represent objects that have different velocities only because they are moving in different directions. A and C represent objects that have different velocities only because they are moving at different speeds. Objects represented by B and C have different velocities because they are moving in different directions and at different speeds. Q: Jerod is riding his bike at a constant speed. As he rides down his street he is moving from east to west. At the end of the block, he turns right and starts moving from south to north, but hes still traveling at the same speed. Has his velocity changed? A: Although Jerods speed hasnt changed, his velocity has changed because he is moving in a different direction. Q: How could you use vector arrows to represent Jerods velocity and how it changes? A: The arrows might look like this: "
Which quantity is a vector?,(A) speed (B) velocity (C) direction (D) distance,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"If speed is constant, velocity",(A) must be zero (B) must be constant (C) can be changing (D) none of the above,C,"Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities. Look again at arrows A and B from the Figure 1.1. They represent objects that have different velocities only because they are moving in different directions. A and C represent objects that have different velocities only because they are moving at different speeds. Objects represented by B and C have different velocities because they are moving in different directions and at different speeds. Q: Jerod is riding his bike at a constant speed. As he rides down his street he is moving from east to west. At the end of the block, he turns right and starts moving from south to north, but hes still traveling at the same speed. Has his velocity changed? A: Although Jerods speed hasnt changed, his velocity has changed because he is moving in a different direction. Q: How could you use vector arrows to represent Jerods velocity and how it changes? A: The arrows might look like this: "
Both speed and velocity are vectors.,(A) true (B) false,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
The symbol t represents a change in time.,(A) true (B) false,A,The motion of an object can be represented by a distance-time graph like the one in Figure 12.8. A distance-time graph shows how the distance from the starting point changes over time. The graph in Figure 12.8 represents a bike trip. The trip began at 7:30 AM (A) and ended at 12:30 PM (F). The rider traveled from the starting point to a destination and then returned to the starting point again. 
The length of a velocity arrow represents distance.,(A) true (B) false,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
A straight line on a distance-time graph means that speed is zero.,(A) true (B) false,B,"In a distance-time graph, the speed of the object is represented by the slope, or steepness, of the graph line. If the line is straight, like the line between A and B in Figure 12.8, then the speed is constant. The average speed can be calculated from the graph. The change in distance (represented by Dd) divided by the change in time (represented by Dt): speed = Dd Dt For example, the speed between A and B in Figure 12.8 is: speed = Dd 20 km 0 km 20 km = = = 20 km/h Dt 8:30 7:30 h 1h If the graph line is horizontal, as it is between B and C, then the slope and the speed are zero: speed = Dd 20 km 20 km 0 km = = = 0 km/h Dt 9:00 8:30 h 0.5 h You Try It! Problem: In Figure 12.8, calculate the speed of the rider between C and D. "
Speed is negative when an object moves backward.,(A) true (B) false,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
Speed depends on both distance and direction.,(A) true (B) false,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
It is easier to calculate average speed than instantaneous speed.,(A) true (B) false,A,"When you travel by car, you usually dont move at a constant speed. Instead you go faster or slower depending on speed limits, traffic lights, the number of vehicles on the road, and other factors. For example, you might travel 65 miles per hour on a highway but only 20 miles per hour on a city street (see the pictures in the Figure 1.1.) You might come to a complete stop at traffic lights, slow down as you turn corners, and speed up to pass other cars. Therefore, your speed at any given instant, or your instantaneous speed, may be very different than your speed at other times. Instantaneous speed is much more difficult to calculate than average speed. Cars race by in a blur of motion on an open highway but crawl at a snails pace when they hit city traffic. "
The slope of a distance-time graph represents the direction of motion.,(A) true (B) false,B,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
Velocity is the scientific term for speed.,(A) true (B) false,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
Speed can only be greater than or equal to zero.,(A) true (B) false,A,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
Objects moving at the same speed always have the same velocity.,(A) true (B) false,B,"Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities. Look again at arrows A and B from the Figure 1.1. They represent objects that have different velocities only because they are moving in different directions. A and C represent objects that have different velocities only because they are moving at different speeds. Objects represented by B and C have different velocities because they are moving in different directions and at different speeds. Q: Jerod is riding his bike at a constant speed. As he rides down his street he is moving from east to west. At the end of the block, he turns right and starts moving from south to north, but hes still traveling at the same speed. Has his velocity changed? A: Although Jerods speed hasnt changed, his velocity has changed because he is moving in a different direction. Q: How could you use vector arrows to represent Jerods velocity and how it changes? A: The arrows might look like this: "
Average speed can be calculated from a distance-time graph.,(A) true (B) false,A,"In a distance-time graph, the speed of the object is represented by the slope, or steepness, of the graph line. If the line is straight, like the line between A and B in Figure 12.8, then the speed is constant. The average speed can be calculated from the graph. The change in distance (represented by Dd) divided by the change in time (represented by Dt): speed = Dd Dt For example, the speed between A and B in Figure 12.8 is: speed = Dd 20 km 0 km 20 km = = = 20 km/h Dt 8:30 7:30 h 1h If the graph line is horizontal, as it is between B and C, then the slope and the speed are zero: speed = Dd 20 km 20 km 0 km = = = 0 km/h Dt 9:00 8:30 h 0.5 h You Try It! Problem: In Figure 12.8, calculate the speed of the rider between C and D. "
Speed equals distance multiplied by time.,(A) true (B) false,B,"Speed is an important aspect of motion. It is a measure of how fast or slow something moves. It depends on how far something travels and how long it takes to travel that far. Speed can be calculated using this general formula: speed = distance time A familiar example is the speed of a car. In the U.S., this is usually expressed in miles per hour (see Figure 12.6). If your family makes a car trip that covers 120 miles and takes 3 hours, then the cars speed is: speed = 120 mi = 40 mi/h 3h The speed of a car may also be expressed in kilometers per hour (km/h). The SI unit for speed is meters per second (m/s). "
A change in speed can occur without a change in velocity.,(A) true (B) false,B,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
A change in velocity can occur without a change in speed.,(A) true (B) false,A,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
measure of both speed and direction,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,B,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
distance  speed,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,G,"Speed is an important aspect of motion. It is a measure of how fast or slow something moves. It depends on how far something travels and how long it takes to travel that far. Speed can be calculated using this general formula: speed = distance time A familiar example is the speed of a car. In the U.S., this is usually expressed in miles per hour (see Figure 12.6). If your family makes a car trip that covers 120 miles and takes 3 hours, then the cars speed is: speed = 120 mi = 40 mi/h 3h The speed of a car may also be expressed in kilometers per hour (km/h). The SI unit for speed is meters per second (m/s). "
speed of a moving object at a given moment,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,C,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
speed  time,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,F,"Speed is an important aspect of motion. It is a measure of how fast or slow something moves. It depends on how far something travels and how long it takes to travel that far. Speed can be calculated using this general formula: speed = distance time A familiar example is the speed of a car. In the U.S., this is usually expressed in miles per hour (see Figure 12.6). If your family makes a car trip that covers 120 miles and takes 3 hours, then the cars speed is: speed = 120 mi = 40 mi/h 3h The speed of a car may also be expressed in kilometers per hour (km/h). The SI unit for speed is meters per second (m/s). "
general term for how quickly or slowly something moves,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,A,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
total distance traveled divided by the time it took to travel that distance,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,D,"Even if speed varies during the course of a trip, its easy to calculate the average speed by using this formula: speed = distance time For example, assume you go on a car trip with your family. The total distance you travel is 120 miles, and it takes 3 hours to travel that far. The average speed for the trip is: 120 mi 3h = 40 mi/h speed = Q: Terri rode her bike very slowly to the top of a big hill. Then she coasted back down the hill at a much faster speed. The distance from the bottom to the top of the hill is 3 kilometers. It took Terri 41 hour to make the round trip. What was her average speed for the entire trip? (Hint: The round-trip distance is 6 km.) A: Terris speed can be calculated as follows: 6 km 0.25 h = 24 km/h speed = "
steepness of a graph line,(A) speed (B) velocity (C) instantaneous speed (D) average speed (E) slope (F) distance (G) time,E,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
Acceleration occurs whenever an object,(A) moves (B) changes position (C) changes direction (D) two of the above,C,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
speed plus direction of motion,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,F,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
negative acceleration,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,C,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
Which of the following is an example of acceleration?,(A) a top spinning at a constant speed (B) a car slowing down through an intersection (C) a train going a steady 80 km/h along a straight track (D) two of the above,D,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
What is the acceleration of a bicycle that goes from 3 m/s to 1 m/s in 2 seconds?,(A) 05 m/s2 (B) 10 m/s2 (C) 15 m/s2 (D) -10 m/s2,D,"Look at the cyclist in the Figure 1.1. With the help of gravity, he speeds up as he goes downhill on a straight part of the trail. His velocity changes from 1 meter per second at the top of the hill to 6 meters per second by the time he reaches the bottom. If it takes him 5 seconds to reach the bottom, what is his average acceleration as he races down the hill? v t 6 m/s  1 m/s = 5s 5 m/s = 5s 1 m/s = 1s = 1 m/s2 acceleration = In words, this means that for each second the cyclist travels downhill, his velocity (in this case, his speed) increases by 1 meter per second on average. Note that the answer to this problem is expressed in m/s2 , which is the SI unit for acceleration. Q: The cyclist slows down at the end of the race. His velocity changes from 6 m/s to 2 m/s during a period of 4 seconds without any change in direction. What was his average acceleration during these 4 seconds? A: Use the equation given above for acceleration: v t 6 m/s  2 m/s = 4s 4 m/s = 4s 1 m/s = 1s = 1 m/s2 acceleration = "
SI unit for acceleration,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,G,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
symbol for a change in velocity,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,E,"The changing velocity of the sprinteror of any other moving person or objectcan be represented by a velocity- time graph like the one in the Figure 1.1 for the sprinter. A velocity-time graph shows how velocity changes over time. The sprinters velocity increases for the first 4 seconds of the race, it remains constant for the next 3 seconds, and it decreases during the last 3 seconds after she crosses the finish line. "
"If the line of a velocity-time graph slopes upward, then acceleration must be",(A) zero (B) positive (C) negative (D) changing,B,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
measure of a change in velocity,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,A,"Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: Can you think of an example of acceleration that doesnt involve a change in speed? A: Driving at a constant speed around a bend in a road is one example. Use your imagination to think of others. "
The x-axis of a velocity-time graph represents,(A) speed (B) velocity (C) direction (D) none of the above,D,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
symbol for a change in time,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,B,The motion of an object can be represented by a distance-time graph like the one in Figure 12.8. A distance-time graph shows how the distance from the starting point changes over time. The graph in Figure 12.8 represents a bike trip. The trip began at 7:30 AM (A) and ended at 12:30 PM (F). The rider traveled from the starting point to a destination and then returned to the starting point again. 
how quickly an object changes position,(A) acceleration (B) t (C) deceleration (D) speed (E) v (F) velocity (G) m/s2,D,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
Acceleration is a vector.,(A) true (B) false,A,"Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: Can you think of an example of acceleration that doesnt involve a change in speed? A: Driving at a constant speed around a bend in a road is one example. Use your imagination to think of others. "
Acceleration shows how quickly velocity changes.,(A) true (B) false,A,"Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: Can you think of an example of acceleration that doesnt involve a change in speed? A: Driving at a constant speed around a bend in a road is one example. Use your imagination to think of others. "
A change in direction without a change in speed is not acceleration.,(A) true (B) false,B,"Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: Can you think of an example of acceleration that doesnt involve a change in speed? A: Driving at a constant speed around a bend in a road is one example. Use your imagination to think of others. "
A velocity-time graph shows how velocity changes over time.,(A) true (B) false,A,"The changing velocity of the sprinteror of any other moving person or objectcan be represented by a velocity- time graph like the one in the Figure 1.1 for the sprinter. A velocity-time graph shows how velocity changes over time. The sprinters velocity increases for the first 4 seconds of the race, it remains constant for the next 3 seconds, and it decreases during the last 3 seconds after she crosses the finish line. "
Acceleration is always greater than or equal to zero.,(A) true (B) false,B,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
Acceleration occurs only when there is a change in speed.,(A) true (B) false,B,"If you are accelerating, you may be able to feel the change in velocity. This is true whether the change is in speed, direction, or both. You often feel acceleration when you ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. When the car slows down, you feel like you are being pushed forward, especially if the change in speed is sudden. If the car changes direction and turns right, you feel as though you are being pushed to the left. With a left turn, you feel a push to the right. The next time you ride in a car, notice how it feels as the car accelerates in each of these ways. "
It is easier to calculate acceleration when both speed and direction are changing.,(A) true (B) false,B,"Calculating acceleration is complicated if both speed and direction are changing or if you want to know acceleration at any given instant in time. However, its relatively easy to calculate average acceleration over a period of time when only speed is changing. Then acceleration is the change in velocity (represented by v) divided by the change in time (represented by t): acceleration = v t "
The y-axis of a velocity-time graph represents distance traveled.,(A) true (B) false,B,"The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given time since it started moving. Q: In the Figure 1.1, what distance has the object traveled from the starting point by the time 5 seconds have elapsed? A: The object has traveled a distance of 50 meters. "
"If a velocity-time graph slopes downward to the right, then acceleration is negative.",(A) true (B) false,A,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
"If velocity is not changing, then acceleration is zero.",(A) true (B) false,A,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
A change in direction with or without a change in speed is velocity.,(A) true (B) false,B,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
"If the slope of a velocity-time graph is a straight line, then velocity must be constant.",(A) true (B) false,B,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
Acceleration shows,(A) how quickly an object travels (B) the direction in which an object moves (C) how far an object travels in a given time (D) how quickly an objects velocity changes,D,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
Which of the following is an example of acceleration?,(A) a change in direction (B) an increase in speed (C) a decrease in speed (D) all of the above,D,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
"If you are riding in a car that decelerates suddenly, you will feel your body",(A) pressed backward (B) pushed to the side (C) thrust forward (D) none of the above,C,"If you are accelerating, you may be able to feel the change in velocity. This is true whether the change is in speed, direction, or both. You often feel acceleration when you ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. When the car slows down, you feel like you are being pushed forward, especially if the change in speed is sudden. If the car changes direction and turns right, you feel as though you are being pushed to the left. With a left turn, you feel a push to the right. The next time you ride in a car, notice how it feels as the car accelerates in each of these ways. "
"To calculate acceleration without a change in direction, you should use the formula",(A) acceleration = v + t (B) acceleration = t/v (C) acceleration = v/t (D) acceleration = v  t,C,"Calculating acceleration is complicated if both speed and direction are changing. Its easier to calculate acceleration when only speed is changing. To calculate acceleration without a change in direction, you just divide the change in velocity (represented by Dv) by the change in time (represented by Dt). The formula for acceleration in this case is: Acceleration = Dv Dt Consider this example. The cyclist in Figure 12.12 speeds up as he goes downhill on this straight trail. His velocity changes from 1 meter per second at the top of the hill to 6 meters per second at the bottom. If it takes 5 seconds for him to reach the bottom, what is his acceleration, on average, as he flies down the hill? Acceleration = Dv 6 m/s 1 m/s 5 m/s 1 m/s = = = = 1 m/s2 Dt 5s 5s 1m In words, this means that for each second the cyclist travels downhill, his velocity increases by 1 meter per second (on average). The answer to this problem is expressed in the SI unit for acceleration: m/s2 (""meters per second squared""). You Try It! Problem: Tranh slowed his skateboard as he approached the street. He went from 8 m/s to 2 m/s in a period of 3 seconds. What was his acceleration? "
"When Sara ran a race on a straight track, her speed changed from 3 m/s to 6 m/s over a time period of 3 seconds. What was her acceleration during that time?",(A) 3 m/s2 (B) 1 m/s2 (C) 2 m/s2 (D) none of the above,B,"Look at the cyclist in the Figure 1.1. With the help of gravity, he speeds up as he goes downhill on a straight part of the trail. His velocity changes from 1 meter per second at the top of the hill to 6 meters per second by the time he reaches the bottom. If it takes him 5 seconds to reach the bottom, what is his average acceleration as he races down the hill? v t 6 m/s  1 m/s = 5s 5 m/s = 5s 1 m/s = 1s = 1 m/s2 acceleration = In words, this means that for each second the cyclist travels downhill, his velocity (in this case, his speed) increases by 1 meter per second on average. Note that the answer to this problem is expressed in m/s2 , which is the SI unit for acceleration. Q: The cyclist slows down at the end of the race. His velocity changes from 6 m/s to 2 m/s during a period of 4 seconds without any change in direction. What was his average acceleration during these 4 seconds? A: Use the equation given above for acceleration: v t 6 m/s  2 m/s = 4s 4 m/s = 4s 1 m/s = 1s = 1 m/s2 acceleration = "
What does a velocity-time graph represent?,(A) how velocity changes over time (B) how distance changes over time (C) acceleration (D) two of the above,D,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
"If speed decreases, then acceleration is",(A) zero (B) positive (C) negative (D) between 0 and 1,C,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
Force can cause a,(A) stationary object to start moving (B) moving object to change speed (C) moving object to change direction (D) all of the above,D,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
Examples of forces include,(A) motion (B) friction (C) acceleration (D) two of the above,B,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
"If gravity pulls you down toward the center of Earth with a force of 500 N, how much upward force does the ground exert on you?",(A) 0N (B) 50 N (C) 500 N (D) none of the above,C,"More than one force may act on an object at the same time. In fact, just about all objects on Earth have at least two forces acting on them at all times. One force is gravity, which pulls objects down toward the center of Earth. The other force is an upward force that may be provided by the ground or other surface. Consider the example in Figure 13.3. A book is resting on a table. Gravity pulls the book downward with a force of 20 newtons. At the same time, the table pushes the book upward with a force of 20 newtons. The combined forces acting on the book  or any other object  are called the net force. This is the overall force acting on an object that takes into account all of the individual forces acting on the object. You can learn more about the concept of net force at this URL:  . "
"In the following sketch, what is the net force acting on the box?",(A) 5 N to the right (B) 5 N to the left (C) 15 N to the right (D) 15 N to the left,C,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
Which diagram represents balanced forces?,(A) a (B) b (C) c (D) d,A,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
Which pair of forces in question 5 differ from each other in both strength and direction?,(A) a (B) b (C) c (D) d,B,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
Mass is a measure of the force of gravity on an object.,(A) true (B) false,B,"Mass is often confused with weight. The two are closely related, but they are not the same. Mass is the amount of matter. Weight is a measure of the force of gravity acting on the mass. On Earth, the force of gravity is constant. If we are comparing objects on Earth, objects with a greater mass also have a greater weight. Weight is measured with a device called a scale. Remember, mass is measured with a balance. You might find an example of a scale in your kitchen or bathroom. Scales detect how forcefully objects are being pulled downward by gravity. The SI unit for weight is the newton (N). A mass of 10 kg has a weight of 100 newtons (N). "
Most objects have at least two forces acting on them at all times.,(A) true (B) false,A,"More than one force may act on an object at the same time. In fact, just about all objects on Earth have at least two forces acting on them at all times. One force is gravity, which pulls objects down toward the center of Earth. The other force is an upward force that may be provided by the ground or other surface. Consider the example in Figure 13.3. A book is resting on a table. Gravity pulls the book downward with a force of 20 newtons. At the same time, the table pushes the book upward with a force of 20 newtons. The combined forces acting on the book  or any other object  are called the net force. This is the overall force acting on an object that takes into account all of the individual forces acting on the object. You can learn more about the concept of net force at this URL:  . "
"If opposing forces are unequal in strength, the net force is less than zero.",(A) true (B) false,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
The SI unit for weight is the newton.,(A) true (B) false,A,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
"When two forces act on an object in the same direction, the net force equals zero.",(A) true (B) false,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
"When forces act in opposite directions on an object, they are subtracted to yield the net force.",(A) true (B) false,A,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
Every sport involves forces.,(A) true (B) false,A,"Force is defined as a push or pull acting on an object. There are several fundamental forces in the universe, including the force of gravity, electromagnetic force, and weak and strong nuclear forces. When it comes to the motion of everyday objects, however, the forces of interest include mainly gravity, friction, and applied force. Applied force is force that a person or thing applies to an object. Q: What forces act on Carsons scooter? A: Gravity, friction, and applied forces all act on Carsons scooter. Gravity keeps pulling both Carson and the scooter toward the ground. Friction between the wheels of the scooter and the ground prevent the scooter from sliding but also slow it down. In addition, Carson applies forces to his scooter to control its speed and direction. "
Forces are always balanced when they act on an object in the same direction.,(A) true (B) false,B,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
"Whenever an object is stationary, it has no forces acting on it.",(A) true (B) false,B,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
Two forces acting in the same direction always result in a stronger force.,(A) true (B) false,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
combination of all the forces acting on an object,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,C,"More than one force may act on an object at the same time. In fact, just about all objects on Earth have at least two forces acting on them at all times. One force is gravity, which pulls objects down toward the center of Earth. The other force is an upward force that may be provided by the ground or other surface. Consider the example in Figure 13.3. A book is resting on a table. Gravity pulls the book downward with a force of 20 newtons. At the same time, the table pushes the book upward with a force of 20 newtons. The combined forces acting on the book  or any other object  are called the net force. This is the overall force acting on an object that takes into account all of the individual forces acting on the object. You can learn more about the concept of net force at this URL:  . "
force that a person or thing exerts on to an object,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,D,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
push or pull acting on an object,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,A,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
forces that produce a net force of zero,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,G,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
example of a force,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,F,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
SI unit for force,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,E,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
forces that produce a net force greater than zero,(A) force (B) unbalanced forces (C) net force (D) applied force (E) newton (F) gravity (G) balanced forces,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
Friction occurs because,(A) all surfaces have some roughness (B) surfaces in contact generate heat (C) chemical reactions take place when surfaces touch (D) none of the above,A,"Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure 13.8. The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction. "
Friction is greater when surfaces are,(A) rougher (B) smoother (C) smaller (D) two of the above,A,"Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier objects also have more friction. Can you explain why? A: Heavier objects press together with greater force, and this causes greater friction between them. Did you ever try to furniture across the floor? Its harder to overcome friction between a heavier piece of furniture and the floor than between lighter pieces and the floor. "
Which factors affect friction?,(A) roughness of the surfaces (B) area of the surfaces (C) force of weight pressing on the surfaces (D) two of the above,D,"Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier objects also have more friction. Can you explain why? A: Heavier objects press together with greater force, and this causes greater friction between them. Did you ever try to furniture across the floor? Its harder to overcome friction between a heavier piece of furniture and the floor than between lighter pieces and the floor. "
Rubbing your hands together makes them warmer because,(A) friction causes molecules to move faster (B) rubbing causes chemical reactions (C) rubbing causes skin cells to release enzymes (D) none of the above,A,"You know that friction produces heat. Thats why rubbing your hands together makes them warmer. But do you know why the rubbing produces heat? Friction causes the molecules on rubbing surfaces to move faster, so they have more heat energy. Heat from friction can be useful. It not only warms your hands. It also lets you light a match (see Figure 13.10). On the other hand, heat from friction can be a problem inside a car engine. It can cause the car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts and makes them slippery so there is less friction. "
"If you pick up and carry a piece of heavy furniture, which type of friction do you have with the floor?",(A) static friction (B) lifting friction (C) sliding friction (D) rolling friction,A,"There are different ways you could move heavy boxes. You could pick them up and carry them. You could slide them across the floor. Or you could put them on a dolly like the one in Figure 13.11 and roll them across the floor. This example illustrates three types of friction: static friction, sliding friction, and rolling friction. Another type of friction is fluid friction. All four types of friction are described below. In each type, friction works opposite the direction of the force applied to a move an object. You can see a video demonstration of the different types of friction at this URL:  (1:07). "
Which way of moving a box produces no friction?,(A) sliding the box across the floor (B) rolling the box on a dolly (C) picking up the box and carrying it (D) none of the above,D,"There are different ways you could move heavy boxes. You could pick them up and carry them. You could slide them across the floor. Or you could put them on a dolly like the one in Figure 13.11 and roll them across the floor. This example illustrates three types of friction: static friction, sliding friction, and rolling friction. Another type of friction is fluid friction. All four types of friction are described below. In each type, friction works opposite the direction of the force applied to a move an object. You can see a video demonstration of the different types of friction at this URL:  (1:07). "
Why do ball bearings reduce friction in a wheel?,(A) Ball bearings prevent the wheel from sliding on the road (B) Rolling friction is less than sliding friction (C) Ball bearings roll instead of slide (D) two of the above,D,"Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards. Ball bearings are another use of rolling friction. You can see what they look like in the Figure 1.2. They let parts of a wheel or other machine roll rather than slide over on another. The ball bearings in this wheel reduce friction between the inner and outer cylinders when they turn. "
Why is it easier to slide a heavy box over a floor that it is to start it sliding in the first place?,(A) The box is lighter when it is sliding (B) The box has less mass when it is moving (C) The box has no friction when it is stationary (D) The box has less friction when it is sliding,D,"Consider the ramp in Figure 16.11. Its easier to push the heavy piece of furniture up the ramp to the truck than to lift it straight up off the ground. However, pushing the furniture over the surface of the ramp creates a lot of friction. Some of the force applied to moving the furniture must be used to overcome the friction. It would be more efficient to use a dolly on wheels to roll the furniture up the ramp. Thats because rolling friction is much less than sliding friction. As a result, the efficiency of the ramp would be greater with a dolly. "
Which statement about rolling friction is false?,(A) It would be hard to ride a bike without it (B) It occurs when ball bearings are used (C) It is stronger than sliding friction (D) It is weaker than static friction,C,"Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why it is much easier to move boxes on a wheeled dolly than by carrying or sliding them. It also explains why most forms of ground transportation use wheels, including cars, 4-wheelers, bicycles, roller skates, and skateboards. Ball bearings are another use of rolling friction (see Figure "
Fluid friction is greater when the object moving through the fluid is,(A) larger (B) smaller (C) faster (D) two of the above,D,"Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your hand and the water. When a skydiver is falling toward Earth with a parachute, fluid friction between the parachute and the air slows the descent (see Figure 13.14). Fluid pressure with the air is called air resistance. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. The very large surface area of a parachute, for example, has greater air resistance than a skydivers body. "
A skydiver uses a parachute to,(A) increase air resistance (B) cushion the landing (C) slow the descent (D) two of the above,D,"""What goes up must come down."" You have probably heard that statement before. At one time this statement was true, but no longer. Since the 1960s, we have sent many spacecraft into space. Some are still traveling away from Earth. So it is possible to overcome gravity. Do you need a giant rocket to overcome gravity? No, you actually overcome gravity every day. Think about when you climb a set of stairs. When you do, you are overcoming gravity. What if you jump on a trampoline? You are overcoming gravity for a few seconds. Everyone can overcome gravity. You just need to apply a force larger than gravity. Think about that the next time you jump into the air. You are overcoming gravity for a brief second. Enjoy it while it lasts. Eventually, gravity will win the battle. "
Which type of friction occurs between a paddle and the water?,(A) static friction (B) sliding friction (C) fluid friction (D) rolling friction,C,"Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases. All four types of friction are described below. "
Friction is never useful.,(A) true (B) false,B,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
Too much friction can cause parts to wear out.,(A) true (B) false,A,"Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of many simple machines, friction can become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts of a machine so they slide over each other more easily. This is how friction is reduced in a car engine. "
Friction can cause scrapes on the skin.,(A) true (B) false,A,"The bodys second line of defense against pathogens includes the inflammatory response. If bacteria enter the skin through a scrape, the area may become red, warm, and painful. These are signs of inflammation. Inflammation is one way the body reacts to infections or injuries. Inflammation is caused by chemicals that are released when skin or other tissues are damaged. The chemicals cause nearby blood vessels to dilate, or expand. This increases blood flow to the damaged area, which makes the area red and slightly warm. The chemicals also attract white blood cells called neutrophils to the wound and cause them to leak out of blood vessels into the damaged tissue. This little girl just got her first scraped knee. It doesnt seem to hurt, but the break in her skin could let pathogens enter her body. Thats why scrapes should be kept clean and protected until they heal. "
Friction is a force that opposes motion.,(A) true (B) false,A,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
Some surfaces are so smooth that they have no friction.,(A) true (B) false,B,"Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure 13.8. The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction. "
The force of friction between surfaces is always useful.,(A) true (B) false,B,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
You use friction when you strike and light a match.,(A) true (B) false,A,"You have probably used activation energy to start a chemical reaction. For example, if youve ever struck a match to light it, then you provided the activation energy needed to start a combustion reaction. When you struck the match on the box, the friction started the match head burning. Combustion is exothermic. Once a match starts to burn, it releases enough energy to activate the next reaction, and the next, and so on. However, the match wont burst into flames on its own. "
It takes more force to slide than to roll a heavy object.,(A) true (B) false,A,Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? Its harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor. 
Sliding friction is greater when the sliding object is heavier.,(A) true (B) false,A,"Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier objects also have more friction. Can you explain why? A: Heavier objects press together with greater force, and this causes greater friction between them. Did you ever try to furniture across the floor? Its harder to overcome friction between a heavier piece of furniture and the floor than between lighter pieces and the floor. "
Friction works in the same direction as the force applied to move an object.,(A) true (B) false,B,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
Sliding friction is stronger than static friction.,(A) true (B) false,B,"Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. Thats why its easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil and when you put on your bikes brakes. "
Rolling friction is weaker than sliding friction.,(A) true (B) false,A,"Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why it is much easier to move boxes on a wheeled dolly than by carrying or sliding them. It also explains why most forms of ground transportation use wheels, including cars, 4-wheelers, bicycles, roller skates, and skateboards. Ball bearings are another use of rolling friction (see Figure "
"When a dolly is stationary, there is rolling friction between the wheels and ground.",(A) true (B) false,B,"Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why it is much easier to move boxes on a wheeled dolly than by carrying or sliding them. It also explains why most forms of ground transportation use wheels, including cars, 4-wheelers, bicycles, roller skates, and skateboards. Ball bearings are another use of rolling friction (see Figure "
Static friction prevents you from sliding out of your chair to the floor.,(A) true (B) false,A,"Static friction acts on objects when they are resting on a surface. For example, if you are walking on a sidewalk, there is static friction between your shoes and the concrete each time you put down your foot (see Figure 13.12). Without this static friction, your feet would slip out from under you, making it difficult to walk. Static friction also allows you to sit in a chair without sliding to the floor. Can you think of other examples of static friction? "
The brakes on a bike create rolling friction.,(A) true (B) false,B,"Rolling friction is friction that acts on objects when they are rolling over a surface. Rolling friction is much weaker than sliding friction or static friction. This explains why most forms of ground transportation use wheels, including bicycles, cars, 4-wheelers, roller skates, scooters, and skateboards. Ball bearings are another use of rolling friction. You can see what they look like in the Figure 1.2. They let parts of a wheel or other machine roll rather than slide over on another. The ball bearings in this wheel reduce friction between the inner and outer cylinders when they turn. "
type of friction between ice skates and ice,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,E,Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? Its harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor. 
any substance that can flow and take the shape of its container,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,D,"Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. "
force that opposes motion between any two surfaces,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,A,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
type of friction between shoes and pavement,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,B,Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? Its harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor. 
type of friction between a parachute and air,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,C,"Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your hand and the water. When a skydiver is falling toward Earth with a parachute, fluid friction between the parachute and the air slows the descent (see Figure 13.14). Fluid pressure with the air is called air resistance. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. The very large surface area of a parachute, for example, has greater air resistance than a skydivers body. "
type of friction between roller skates and concrete,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,G,Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? Its harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor. 
type of friction between an object and a gas or liquid,(A) friction (B) static friction (C) air resistance (D) fluid (E) sliding friction (F) fluid friction (G) rolling friction,F,"Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your hand and the water. When a skydiver is falling toward Earth with a parachute, fluid friction between the parachute and the air slows the descent (see Figure 13.14). Fluid pressure with the air is called air resistance. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. The very large surface area of a parachute, for example, has greater air resistance than a skydivers body. "
The SI unit for weight is the,(A) gram (B) kilogram (C) newton (D) pound,C,"Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale in Figure 13.16. The scale measures the force with which gravity pulls an object downward. "
Newtons law of universal gravitation states that the force of gravity,(A) affects all objects in the universe (B) is stronger for objects with more mass (C) is stronger for objects that are closer together (D) all of the above,D,"Newton was the first one to suggest that gravity is universal and affects all objects in the universe. Thats why his law of gravity is called the law of universal gravitation. Universal gravitation means that the force that causes an apple to fall from a tree to the ground is the same force that causes the moon to keep moving around Earth. Universal gravitation also means that while Earth exerts a pull on you, you exert a pull on Earth. In fact, there is gravity between you and every mass around you  your desk, your book, your pen. Even tiny molecules of gas are attracted to one another by the force of gravity. Newtons law had a huge impact on how people thought about the universe. It explains the motion of objects not only on Earth but in outer space as well. You can learn more about Newtons law of gravity in the video at this URL: "
Gravity causes all objects to,(A) attract one another (B) have projectile motion (C) accelerate when they fall toward Earth (D) two of the above,D,Regardless of what gravity is  a force between masses or the result of curves in space and time  the effects of gravity on motion are well known. You already know that gravity causes objects to fall down to the ground. Gravity affects the motion of objects in other ways as well. 
The only reason that a leaf falls to the ground more slowly than an acorn is that the leaf has,(A) less mass (B) more air resistance (C) a weaker force of gravity (D) less acceleration due to gravity,B,"Did you ever see a scene like the one in Figure 17.4? In many parts of the world, trees lose their leaves in autumn. The leaves turn color and then fall from the trees to the ground. As the leaves are falling, they have kinetic energy. While they are still attached to the trees they also have energy, but its not because of motion. Instead, they have stored energy, called potential energy. An object has potential energy because of its position or shape. For example leaves on trees have potential energy because they could fall due to the pull of gravity. "
"On Earth, a mass of 1 kilogram exerts a downward force due to gravity of about",(A) 1 N (B) 5 N (C) 10 N (D) 15 N,C,"At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? At Earths gravity, 1 kg has a weight of 10 N. Therefore, 10 kg has a weight of (10 kg x 10 m/s2 ) = 100 N. "
Satellites orbit Earth because of gravity.,(A) true (B) false,A,Satellites orbit high above the Earth in several ways. Different orbits are important for viewing different things about the planet. 
An object has a greater mass on Earth than it does on the moon.,(A) true (B) false,B,"If you have a mass of 50 kg on Earth, what is your weight in newtons? An object with more mass is pulled by gravity with greater force. Mass and weight are closely related. However, the weight of an object can change if the force of gravity changes. On Earth, the force of gravity is the same everywhere. So how does the force of gravity change? It doesnt if you stay on Earth. What if we travel to another planet or moon in our solar system? Look at the photo of astronaut Edwin E. Aldrin Jr. taken by fellow astronaut Neil Armstrong in the Figure ??. They were the first humans to walk on the moon. An astronaut weighs less on the moon than he would on Earth. This is because the moons gravity is weaker than Earths. The astronauts mass, on the other hand, did not change. He still contained the same amount of matter on the moon as he did on Earth. If the astronaut weighed 175 pounds on Earth, he would have weighed only 29 pounds on the moon. If his mass on Earth was 80 kg, what would his mass have been on the moon? [Figure 3] "
Molecules of gas are attracted toward one another by gravity.,(A) true (B) false,A,"Imagine a container of gas molecules like the one in the Figure 1.1. The container in the sketch has a lid that can be pushed down to shrink the volume of the gas inside. Notice what happens as the lid is lowered. The gas molecules crowd closer together because there is less space for them to occupy and they have nowhere else to go. Gas molecules have a lot of energy. They are always moving and bouncing off each other and anything else in their path. When gas molecules bump into things, it creates pressure. Pressure is greater when gas molecules occupy a smaller space, because the greater crowding results in more collisions. In other words, decreasing the volume of a gas increases its pressure. "
All of the solar systems in the universe formed because of gravity.,(A) true (B) false,A,"The most widely accepted explanation of how the solar system formed is called the nebular hypothesis. According to this hypothesis, the Sun and the planets of our solar system formed about 4.6 billion years ago from the collapse of a giant cloud of gas and dust, called a nebula. The nebula was drawn together by gravity, which released gravitational potential energy. As small particles of dust and gas smashed together to create larger ones, they released kinetic energy. As the nebula collapsed, the gravity at the center increased and the cloud started to spin because of its angular momentum. As it collapsed further, the spinning got faster, much as an ice skater spins faster when he pulls his arms to his sides during a spin. Much of the clouds mass migrated to its center but the rest of the material flattened out in an enormous disk. The disk contained hydrogen and helium, along with heavier elements and even simple organic molecules. "
The mass of an object affects its force of gravity.,(A) true (B) false,A,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity. For example, because Earth is so massive, it attracts you and your desk more strongly than you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. This is illustrated in Figure You can apply these relationships among mass, distance, and gravity by designing your own roller coaster at this URL:  . "
Gravity acts only between objects that are close together or touching.,(A) true (B) false,B,"Gravity has traditionally been defined as a force of attraction between things that have mass. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. Gravity can act between objects that are not even touching. In fact, gravity can act over very long distances. However, the farther two objects are from each other, the weaker is the force of gravity between them. Less massive objects also have less gravity than more massive objects. "
Objects that are closer together have a weaker force of gravity.,(A) true (B) false,B,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
All objects have the same acceleration due to gravity.,(A) true (B) false,A,"When gravity pulls objects toward the ground, it causes them to accelerate. Acceleration due to gravity equals 9.8 m/s2 . In other words, the velocity at which an object falls toward Earth increases each second by 9.8 m/s. Therefore, after 1 second, an object is falling at a velocity of 9.8 m/s. After 2 seconds, it is falling at a velocity of 19.6 m/s (9.8 m/s  2), and so on. This is illustrated in Figure 13.20. You can compare the acceleration due to gravity on Earth, the moon, and Mars with the interactive animation called ""Freefall"" at this URL: http://jersey.uoregon.edu/vlab/ . You might think that an object with greater mass would accelerate faster than an object with less mass. After all, its greater mass means that it is pulled by a stronger force of gravity. However, a more massive object accelerates at the same rate as a less massive object. The reason? The more massive object is harder to move because of its greater mass. As a result, it ends up moving at the same acceleration as the less massive object. Consider a bowling ball and a basketball. The bowling ball has greater mass than the basketball. However, if you were to drop both balls at the same time from the same distance above the ground, they would reach the ground together. This is true of all falling objects, unless air resistance affects one object more than another. For example, a falling leaf is slowed down by air resistance more than a falling acorn because of the leafs greater surface area. However, if the leaf and acorn were to fall in the absence of air (that is, in a vacuum), they would reach the ground at the same time. "
Earth has stronger gravity than the moon.,(A) true (B) false,A,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
The curved path of an arrow is called its orbit.,(A) true (B) false,B,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
Weight is measured with a balance.,(A) true (B) false,B,"Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale in Figure 13.16. The scale measures the force with which gravity pulls an object downward. "
People have known about gravity for thousands of years.,(A) true (B) false,A,"People have known about gravity for thousands of years. After all, they constantly experienced gravity in their daily lives. They knew that things always fall toward the ground. However, it wasnt until Sir Isaac Newton developed his law of gravity in the late 1600s that people really began to understand gravity. Newton is pictured in Figure 13.17. "
The moon has both forward velocity and acceleration toward Earth.,(A) true (B) false,A,"Just as Earth orbits the sun, the moon also orbits Earth. The moon is affected by Earths gravity more than it is by the gravity of the sun because the moon is much closer to Earth. The gravity between Earth and the moon pulls the moon toward Earth. At the same time, the moon has forward velocity that partly counters the force of Earths gravity. So the moon orbits Earth instead of falling down to the surface of the planet. The Figure 1.2 shows the forces involved in the moons orbital motion around Earth. In the diagram, v represents the forward velocity of the moon, and a represents the acceleration due to gravity between Earth and the moon. The line encircling Earth shows the moons actual orbit, which results from the combination of v and a. "
Einsteins theory of gravity is better than Newtons law of gravity at predicting how all objects move.,(A) true (B) false,A,"Newtons idea of gravity can predict the motion of most but not all objects. In the early 1900s, Albert Einstein came up with a theory of gravity that is better at predicting how all objects move. Einstein showed mathematically that gravity is not really a force in the sense that Newton thought. Instead, gravity is a result of the warping, or curving, of space and time. Imagine a bowling ball pressing down on a trampoline. The surface of the trampoline would curve downward instead of being flat. Einstein theorized that Earth and other very massive bodies affect space and time around them in a similar way. This idea is represented in Figure 13.19. According to Einstein, objects curve toward one another because of the curves in space and time, not because they are pulling on each other with a force of attraction as Newton thought. You can see an animation of Einsteins theory of gravity at this URL: http://einstein. theory of gravity, go to this URL: "
Einstein defined gravity as a force of attraction between objects with mass.,(A) true (B) false,B,"Gravity has traditionally been defined as a force of attraction between two masses. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. The effect of gravity is that objects exert a pull on other objects. Unlike friction, which acts only between objects that are touching, gravity also acts between objects that are not touching. In fact, gravity can act over very long distances. "
SI unit for weight,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,G,"Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale in Figure 13.16. The scale measures the force with which gravity pulls an object downward. "
motion of an object subject to horizontal force and the force of gravity,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,E,"Earths gravity also affects the acceleration of objects that start out moving horizontally, or parallel to the ground. Look at Figure 13.21. A cannon shoots a cannon ball straight ahead, giving the ball horizontal motion. At the same time, gravity pulls the ball down toward the ground. Both forces acting together cause the ball to move in a curved path. This is called projectile motion. Projectile motion also applies to other moving objects, such as arrows shot from a bow. To hit the bulls eye of a target with an arrow, you actually have to aim for a spot above the bulls eye. Thats because by the time the arrow reaches the target, it has started to curve downward toward the ground. Figure 13.22 shows what happens if you aim at the bulls eye instead of above it. You can access interactive animations of projectile motion at these URLs: http://phet.colorado.edu/en/simulation/projectile-motion http://jersey.uoregon.edu/vlab/ (Select the applet entitled Cannon.) "
force of attraction between two masses,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,A,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
scientist who proposed that gravity is due to curves in space and time,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,F,"Newtons idea of gravity can predict the motion of most but not all objects. In the early 1900s, Albert Einstein came up with a theory of gravity that is better at predicting how all objects move. Einstein showed mathematically that gravity is not really a force in the sense that Newton thought. Instead, gravity is a result of the warping, or curving, of space and time. Imagine a bowling ball pressing down on a trampoline. The surface of the trampoline would curve downward instead of being flat. Einstein theorized that Earth and other very massive bodies affect space and time around them in a similar way. This idea is represented in Figure 13.19. According to Einstein, objects curve toward one another because of the curves in space and time, not because they are pulling on each other with a force of attraction as Newton thought. You can see an animation of Einsteins theory of gravity at this URL: http://einstein. theory of gravity, go to this URL: "
measure of the force of gravity,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,D,"Weight measures the force of gravity pulling downward on an object. The SI unit for weight, like other forces, is the Newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 Newtons because of the pull of Earths gravity. On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale shown in the Figure 1.1. The scale measures the force with which gravity pulls an object downward. To delve a little deeper into weight and gravity, watch this video: Click image to the left or use the URL below. URL: "
"path of one object around another, such as the moon around Earth",(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,C,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
scientist who proposed the law of universal gravitation,(A) gravity (B) Isaac Newton (C) orbit (D) weight (E) projectile motion (F) Albert Einstein (G) newton,B,"Newton was the first one to suggest that gravity is universal and affects all objects in the universe. Thats why Newtons law of gravity is called the law of universal gravitation. Universal gravitation means that the force that causes an apple to fall from a tree to the ground is the same force that causes the moon to keep moving around Earth. Universal gravitation also means that while Earth exerts a pull on you, you exert a pull on Earth. In fact, there is gravity between you and every mass around youyour desk, your book, your pen. Even tiny molecules of gas are attracted to one another by the force of gravity. Q: Newtons law of universal gravitation had a huge impact on how people thought about the universe. Why do you think it was so important? A: Newtons law was the first scientific law that applied to the entire universe. It explains the motion of objects not only on Earth but in outer space as well. "
Gravity always causes objects to,(A) repel each other (B) circle each other (C) attract each other (D) two of the above,C,Regardless of what gravity is  a force between masses or the result of curves in space and time  the effects of gravity on motion are well known. You already know that gravity causes objects to fall down to the ground. Gravity affects the motion of objects in other ways as well. 
"Unlike friction, gravity",(A) is a force (B) acts over a distance (C) acts between objects that are not touching (D) two of the above,D,"Gravity is a force, but not like other forces you may know. Gravity is a bit special. You know that a force is a push or pull. If you push a ball, it starts to roll. If you lift a book, it moves upward. Now, imagine you drop a ball. It falls to the ground. Can you see the force pulling it down? That is what makes gravity really cool. It is invisible. Invisible means you cannot see it. But wait, it has even more surprises. Gravity holds planets in place around the Sun. Gravity keeps the Moon from flying off into space. Gravity exerts a force on objects that are not even touching. In fact, gravity can act over very large distances. However, the force does get weaker the farther apart the objects are. "
What does weight measure?,(A) size (B) mass (C) force (D) volume,C,"Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale in Figure 13.16. The scale measures the force with which gravity pulls an object downward. "
Jody has a mass of 50 kilograms. What is his weight on Earth?,(A) 5N (B) 50 N (C) 500 N (D) 5000 N,C,"At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? At Earths gravity, 1 kg has a weight of 10 N. Therefore, 10 kg has a weight of (10 kg x 10 m/s2 ) = 100 N. "
There is gravity between you and,(A) Earth (B) the moon (C) your desk (D) all of the above,D,"You are already very familiar with Earths gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects that are above the surfacefrom meteors to skydiversdown to the ground. Gravity between Earth and the moon and between Earth and artificial satellites keeps all these objects circling around Earth. Gravity also keeps Earth and the other planets moving around the much more massive sun. Q: There is a force of gravity between Earth and you and also between you and all the objects around you. When you drop a paper clip, why doesnt it fall toward you instead of toward Earth? A: Earth is so much more massive than you that its gravitational pull on the paper clip is immensely greater. "
The moon orbits Earth rather than the sun because,(A) the suns gravity is weaker than Earths (B) the moon is smaller than Earth (C) Earth already orbits the sun (D) the moon is closer to Earth,D,"Just as Earth orbits the sun, the moon also orbits Earth. The moon is affected by Earths gravity more than it is by the gravity of the sun because the moon is much closer to Earth. The gravity between Earth and the moon pulls the moon toward Earth. At the same time, the moon has forward velocity that partly counters the force of Earths gravity. So the moon orbits Earth instead of falling down to the surface of the planet. The Figure 1.2 shows the forces involved in the moons orbital motion around Earth. In the diagram, v represents the forward velocity of the moon, and a represents the acceleration due to gravity between Earth and the moon. The line encircling Earth shows the moons actual orbit, which results from the combination of v and a. "
An object with greater mass,(A) has greater acceleration when it falls (B) has a weaker force of gravity (C) is less affected by gravity (D) has greater weight,D,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
Which of the following items has the property of elasticity?,(A) rubber band (B) paper clip (C) toothpick (D) iron nail,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
force exerted on a material that is pulled apart,(A) elastic force (B) stretching force (C) compressing force (D) elasticity (E) spring,B,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
structure that returns to its original shape after being stretched or compressed,(A) elastic force (B) stretching force (C) compressing force (D) elasticity (E) spring,E,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
When does an elastic material exert elastic force?,(A) before it is stretched (B) as it is stretched (C) when it is released (D) two of the above,D,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
force exerted on a material that is pushed together,(A) elastic force (B) stretching force (C) compressing force (D) elasticity (E) spring,C,"Stress is the force applied to an object. In geology, stress is the force per unit area that is placed on a rock. Four types of stresses act on materials. A deeply buried rock is pushed down by the weight of all the material above it. Since the rock cannot move, it cannot deform. This is called confining stress. Compression squeezes rocks together, causing rocks to fold or fracture (break) (Figure 1.1). Compression is the most common stress at convergent plate boundaries. Stress caused these rocks to fracture. Rocks that are pulled apart are under tension. Rocks under tension lengthen or break apart. Tension is the major type of stress at divergent plate boundaries. When forces are parallel but moving in opposite directions, the stress is called shear (Figure 1.2). Shear stress is the most common stress at transform plate boundaries. Shearing in rocks. The white quartz vein has been elongated by shear. When stress causes a material to change shape, it has undergone strain or deformation. Deformed rocks are common in geologically active areas. A rocks response to stress depends on the rock type, the surrounding temperature, the pressure conditions the rock is under, the length of time the rock is under stress, and the type of stress. "
What happens when you pull on a bungee cord?,(A) It stretches (B) It resists the change in shape (C) It exerts force in the opposite direction (D) all of the above,D,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material like a bungee cord, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. The farther the material is stretched or compressed, the greater the elastic force becomes. As soon as the stretching or compressing force is released, elastic force causes the material to spring back to its original shape. Click image to the left or use the URL below. URL:  Q: What force stretches the bungee cord after the jumper jumps? When does the bungee cord snap back to its original shape? A: After the bungee jumper jumps, he accelerates toward the ground due to gravity. His weight stretches the bungee cord. As the bungee cord stretches, it exerts elastic force upward against the jumper, which slows his descent and brings him to a momentary stop. Then the bungee cord springs back to its original shape, and the jumper bounces upward. "
"When you jump on a trampoline, the surface of the trampoline",(A) changes shape (B) exerts elastic force (C) pushes you up into the air (D) all of the above,D,"""What goes up must come down."" You have probably heard that statement before. At one time this statement was true, but no longer. Since the 1960s, we have sent many spacecraft into space. Some are still traveling away from Earth. So it is possible to overcome gravity. Do you need a giant rocket to overcome gravity? No, you actually overcome gravity every day. Think about when you climb a set of stairs. When you do, you are overcoming gravity. What if you jump on a trampoline? You are overcoming gravity for a few seconds. Everyone can overcome gravity. You just need to apply a force larger than gravity. Think about that the next time you jump into the air. You are overcoming gravity for a brief second. Enjoy it while it lasts. Eventually, gravity will win the battle. "
counter force exerted by an elastic material that is stretched or compressed,(A) elastic force (B) stretching force (C) compressing force (D) elasticity (E) spring,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
Elastic force causes an elastic material to,(A) push back when pulled (B) return to its original shape (C) take the shape of its container (D) two of the above,D,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
ability of a material to return to its original shape after being stretched or compressed,(A) elastic force (B) stretching force (C) compressing force (D) elasticity (E) spring,D,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
Something that is elastic springs back after being stretched.,(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
An elastic material resists a change in shape.,(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
Elastic force is not very useful.,(A) true (B) false,B,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
"When you use a resistance band, resistance comes from elastic force.",(A) true (B) false,A,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
Glass is an example of an elastic material.,(A) true (B) false,B,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
Items that are elastic include,(A) metal wires (B) concrete blocks (C) plastic spring toys (D) all of the above,C,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
"When you compress a spring, it resists the change in shape.",(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
A rubber band keeps a newspaper tightly rolled because it,(A) can be tied tightly (B) exerts elastic force (C) is unbreakable (D) none of the above,B,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
Paper is an example of an elastic material.,(A) true (B) false,B,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
"When you compress a spring, it",(A) resists the change in shape (B) exerts a force in the same direction (C) permanently changes to a new shape (D) two of the above,A,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
"As you stretch a bungee cord, its elastic force gets stronger.",(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material like a bungee cord, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. The farther the material is stretched or compressed, the greater the elastic force becomes. As soon as the stretching or compressing force is released, elastic force causes the material to spring back to its original shape. Click image to the left or use the URL below. URL:  Q: What force stretches the bungee cord after the jumper jumps? When does the bungee cord snap back to its original shape? A: After the bungee jumper jumps, he accelerates toward the ground due to gravity. His weight stretches the bungee cord. As the bungee cord stretches, it exerts elastic force upward against the jumper, which slows his descent and brings him to a momentary stop. Then the bungee cord springs back to its original shape, and the jumper bounces upward. "
"When you release a stretched bungee cord, it returns to its original shape because of gravity.",(A) true (B) false,B,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material like a bungee cord, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. The farther the material is stretched or compressed, the greater the elastic force becomes. As soon as the stretching or compressing force is released, elastic force causes the material to spring back to its original shape. Click image to the left or use the URL below. URL:  Q: What force stretches the bungee cord after the jumper jumps? When does the bungee cord snap back to its original shape? A: After the bungee jumper jumps, he accelerates toward the ground due to gravity. His weight stretches the bungee cord. As the bungee cord stretches, it exerts elastic force upward against the jumper, which slows his descent and brings him to a momentary stop. Then the bungee cord springs back to its original shape, and the jumper bounces upward. "
Springs are used in,(A) beds (B) cars (C) scales (D) all of the above,D,"Elastic force can be very useful. You probably use it yourself every day. A few common uses of elastic force are pictured in Figure 13.25. Did you ever use a resistance band like the one in the figure? When you pull on the band, it stretches but doesnt break. The resistance you feel when you pull on it is elastic force. The resistance of the band to stretching is what gives your muscles a workout. After you stop pulling on the band, it returns to its original shape, ready for the next workout. Springs like the ones in Figure 13.26 also have elastic force when they are stretched or compressed. And like stretchy materials, they return to their original shape when the stretching or compressing force is released. Because of these properties, springs are used in scales to measure weight. They also cushion the ride in a car and provide springy support beneath a mattress. Can you think of other uses of springs? "
Something that is elastic returns to its original shape after being compressed.,(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
What happens when the stretching force on an elastic material is released?,(A) The material breaks (B) The material remains stretched out (C) The material starts to exert elastic force (D) The material snaps back to its original shape,D,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material like a bungee cord, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. The farther the material is stretched or compressed, the greater the elastic force becomes. As soon as the stretching or compressing force is released, elastic force causes the material to spring back to its original shape. Click image to the left or use the URL below. URL:  Q: What force stretches the bungee cord after the jumper jumps? When does the bungee cord snap back to its original shape? A: After the bungee jumper jumps, he accelerates toward the ground due to gravity. His weight stretches the bungee cord. As the bungee cord stretches, it exerts elastic force upward against the jumper, which slows his descent and brings him to a momentary stop. Then the bungee cord springs back to its original shape, and the jumper bounces upward. "
Newtons first law of motion is also called the law of,(A) mass (B) inertia (C) velocity (D) unbalanced forces,B,"Newtons first law of motion is also called the law of inertia. Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. Thats why its important to always wear a seat belt. Inertia also explains the amusement park ride in Figure 14.1. The car keeps changing direction, but the riders keep moving in the same direction as before. They slide to the opposite side of the car as a result. You can see an animation of inertia at this URL: "
Newtons first law of motion states than an objects motion will not change unless,(A) the net force acting on it is greater than zero (B) a force continues to be applied to the object (C) its inertia is stronger than the applied force (D) the object has no inertia,A,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
Overcoming an objects inertia always requires a(n),(A) large mass (B) massive force (C) unbalanced force (D) two of the above,C,"To change the motion of an object, inertia must be overcome by an unbalanced force acting on the object. Until the soccer player kicks the ball in Figure 14.4, the ball remains motionless on the ground. However, when the ball is kicked, the force on it is suddenly unbalanced. The ball starts moving across the field because its inertia has been overcome. "
"Once an applied force causes an object to start moving, the object keeps moving because",(A) the force continues to be applied to it (B) no other force is acting on it (C) it has inertia (D) none of the above,C,"Newtons first law of motion is also called the law of inertia. Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. Thats why its important to always wear a seat belt. Inertia also explains the amusement park ride in Figure 14.1. The car keeps changing direction, but the riders keep moving in the same direction as before. They slide to the opposite side of the car as a result. You can see an animation of inertia at this URL: "
It is more difficult to start a 50-kg box sliding across the floor than a 5-kg box because the 50-kg box has greater,(A) size (B) inertia (C) volume (D) velocity,B,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
"If the net force acting on any object is zero, the object will",(A) not move (B) change its motion (C) have zero velocity (D) none of the above,D,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
"Once an object starts moving along a clear path, it would keep moving at the same velocity if it were not for",(A) inertia (B) friction (C) an unbalanced force (D) two of the above,D,"Objects have the same velocity only if they are moving at the same speed and in the same direction. Objects moving at different speeds, in different directions, or both have different velocities. Look again at arrows A and B from the Figure 1.1. They represent objects that have different velocities only because they are moving in different directions. A and C represent objects that have different velocities only because they are moving at different speeds. Objects represented by B and C have different velocities because they are moving in different directions and at different speeds. Q: Jerod is riding his bike at a constant speed. As he rides down his street he is moving from east to west. At the end of the block, he turns right and starts moving from south to north, but hes still traveling at the same speed. Has his velocity changed? A: Although Jerods speed hasnt changed, his velocity has changed because he is moving in a different direction. Q: How could you use vector arrows to represent Jerods velocity and how it changes? A: The arrows might look like this: "
"If you run into a curb on your bike, you might fly forward over the handlebars because of",(A) air resistance (B) inertia (C) friction (D) gravity,B,"Riding a bicycle might be easy. But the forces that allow humans to balance atop a bicycle are complex. QUEST visits Davis  a city that loves its bicycles  to take a ride on a research bicycle and explore a collection of antique bicycles. Scientists say studying the complicated physics of bicycling can lead to the design of safer, and more efficient bikes. For more information on the science of riding a bicycle, see  MEDIA Click image to the left or use the URL below. URL: "
An objects velocity will not change unless it is acted on by a(n),(A) net force (B) strong force (C) unbalanced force (D) opposite but equal force,C,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
Inertia causes a stationary object to,(A) start moving (B) remain stationary (C) have an increase in velocity (D) change its speed or direction,B,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
The direction of a moving object will not change if the net force acting on it is,(A) greater than zero (B) less than zero (C) zero (D) two of the above,C,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
Inertia is the tendency of an object to resist motion.,(A) true (B) false,B,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
Newtons first law of motion is also called the law of acceleration.,(A) true (B) false,B,"Newtons first law of motion is also called the law of inertia. Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. Thats why its important to always wear a seat belt. Inertia also explains the amusement park ride in Figure 14.1. The car keeps changing direction, but the riders keep moving in the same direction as before. They slide to the opposite side of the car as a result. You can see an animation of inertia at this URL: "
"If an object is at rest, inertia will keep it at rest.",(A) true (B) false,A,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
The inertia of an object is determined by its speed.,(A) true (B) false,B,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
Newtons first law relates motion to balanced and unbalanced forces.,(A) true (B) false,A,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
The speed of an object changes only when it is acted on by an unbalanced force.,(A) true (B) false,A,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
An object with greater mass has greater inertia.,(A) true (B) false,A,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
A stationary object resists movement only because of gravity.,(A) true (B) false,B,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
Balanced forces are needed to change an objects motion.,(A) true (B) false,B,"To change the motion of an object, inertia must be overcome by an unbalanced force acting on the object. Until the soccer player kicks the ball in Figure 14.4, the ball remains motionless on the ground. However, when the ball is kicked, the force on it is suddenly unbalanced. The ball starts moving across the field because its inertia has been overcome. "
The tendency of an object to resist a change in motion depends on its mass.,(A) true (B) false,A,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
"If the net force acting on an object is zero, its inertia is also zero.",(A) true (B) false,B,"Newtons first law of motion is also called the law of inertia. Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. Thats why its important to always wear a seat belt. Inertia also explains the amusement park ride in Figure 14.1. The car keeps changing direction, but the riders keep moving in the same direction as before. They slide to the opposite side of the car as a result. You can see an animation of inertia at this URL: "
A rolling ball will roll forever unless it runs into another object.,(A) true (B) false,B,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
The tendency of an object to resist a change in its motion depends on the objects size.,(A) true (B) false,B,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
"When you are moving at a high rate of speed, inertia makes is hard to stop.",(A) true (B) false,A,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
Newtons first law of motion applies only to objects that are already moving.,(A) true (B) false,B,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
combination of all the forces acting on an object,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,F,"More than one force may act on an object at the same time. In fact, just about all objects on Earth have at least two forces acting on them at all times. One force is gravity, which pulls objects down toward the center of Earth. The other force is an upward force that may be provided by the ground or other surface. Consider the example in Figure 13.3. A book is resting on a table. Gravity pulls the book downward with a force of 20 newtons. At the same time, the table pushes the book upward with a force of 20 newtons. The combined forces acting on the book  or any other object  are called the net force. This is the overall force acting on an object that takes into account all of the individual forces acting on the object. You can learn more about the concept of net force at this URL:  . "
force that opposes the motion of any object,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,C,"Friction is a force that opposes motion between any surfaces that are touching. Friction can work for or against us. For example, putting sand on an icy sidewalk increases friction so you are less likely to slip. On the other hand, too much friction between moving parts in a car engine can cause the parts to wear out. Other examples of friction are illustrated in the two Figures 1.1 and 1.2. "
an objects motion will not change unless an unbalanced force acts on it,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,D,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
factor that determines the inertia of an object,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,E,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
type of force needed to overcome inertia of an object,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,B,"To change the motion of an object, inertia must be overcome by an unbalanced force acting on the object. Until the soccer player kicks the ball in Figure 14.4, the ball remains motionless on the ground. However, when the ball is kicked, the force on it is suddenly unbalanced. The ball starts moving across the field because its inertia has been overcome. "
tendency of an object to resist a change in motion,(A) inertia (B) unbalanced force (C) friction (D) law of inertia (E) mass (F) net force,A,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
Which two factors have an inverse relationship?,(A) force and acceleration (B) force and mass (C) mass and gravity (D) mass and acceleration,D,"As the volume of gas in the container pictured in the Figure 1.1 gets smaller, the pressure of the gas molecules becomes greater. When two variables change in opposite directions like this, the variables have an inverse, or upside-down, relationship. Q: How could you show an inverse relationship with a graph? Sketch a graph to show what the relationship between gas volume and pressure might look like. Let the x-axis represent volume (V) and the y-axis represent pressure (P). A: Did you sketch a graph like the one in the Figure 1.2? Lets see why this graph is correct. Find the point on the line where volume is smallest. Thats were pressure is highest. Then find the point where volume is largest. Thats where pressure is lowest. Whenever you see a graph with this shape, it usually represents variables that have an inverse relationship, like gas volume and pressure. "
Any change in the motion of an object is called,(A) speed (B) velocity (C) direction (D) acceleration,D,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
"In the equation F = m  a, if a is the acceleration due to gravity, what is F?",(A) mass (B) weight (C) friction (D) frequency,B,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
"If you push a 20-kg box with a force of 10 N, what is its acceleration?",(A) 20 m/s2 (B) 10 m/s2 (C) 2 m/s2 (D) 05 m/s2,D,"The equation for acceleration given above can be used to calculate the acceleration of an object that is acted on by an unbalanced force. For example, assume you are pushing a large wooden trunk, like the one shown in Figure acceleration of the trunk, substitute these values in the equation for acceleration: a= F 20 N 2N = = m 10 kg kg Recall that one newton (1 N) is the force needed to cause a 1-kilogram mass to accelerate at 1 m/s2 . Therefore, force can also be expressed in the unit kgm/s2 . This way of expressing force can be substituted for newtons in the solution to the problem: a= 2 N 2 kg  m/s2 = = 2 m/s2 kg kg Why are there no kilograms in the final answer to this problem? The kilogram units in the numerator and denominator of the fraction cancel out. As a result, the answer is expressed in the correct units for acceleration: m/s2 . You Try It! Problem: Assume that you add the weights to the trunk in Figure 14.7. If you push the trunk and weights with a force of 20 N, what will be the trunks acceleration? Need more practice? You can find additional problems at this URL: "
Newton determined that the acceleration of an object depends on the net force acting on the object and the objects,(A) size (B) mass (C) weight (D) velocity,B,"Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the objects mass. The relationships between these two factors and motion make up Newtons second law of motion. This law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Net force , or Mass F a= m Acceleration = You can watch a video about how Newtons second law of motion applies to football at this URL: http://science36 "
The relationship between mass and inertia is described by Newtons second law of motion.,(A) true (B) false,B,"Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the objects mass. The relationships between these two factors and motion make up Newtons second law of motion. This law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Net force , or Mass F a= m Acceleration = You can watch a video about how Newtons second law of motion applies to football at this URL: http://science36 "
Newton determined that there is a direct relationship between force and mass.,(A) true (B) false,A,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
Any change in velocity for any reason is called acceleration.,(A) true (B) false,A,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
Newtons second law shows that there is a direct relationship between net force and acceleration.,(A) true (B) false,A,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
"The greater the net force applied to a given object, the more it will accelerate.",(A) true (B) false,A,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
Doubling the mass of an object doubles its weight.,(A) true (B) false,A,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
"The greater the mass of an object, the more it will accelerate when a given net force is applied to it.",(A) true (B) false,B,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
A net force of 1 N applied to a mass of 1 kg results in an acceleration of 0.5 m/s2 .,(A) true (B) false,B,"This equation for acceleration can be used to calculate the acceleration of an object that is acted on by a net force. For example, Xander and his scooter have a total mass of 50 kilograms. Assume that the net force acting on Xander and the scooter is 25 Newtons. What is his acceleration? Substitute the relevant values into the equation for acceleration: F = 25 N = 0.5 N a= m 50 kg kg The Newton is the SI unit for force. It is defined as the force needed to cause a 1-kilogram mass to accelerate at 1 m/s2 . Therefore, force can also be expressed in the unit kg  m/s2 . This way of expressing force can be substituted for Newtons in Xanders acceleration so the answer is expressed in the SI unit for acceleration, which is m/s2 : 2 0.5 kgm/s a = 0.5kgN = = 0.5 m/s2 kg Q: Why are there no kilograms in the final answer to this problem? A: The kilogram units in the numerator and denominator of the fraction cancel out. As a result, the answer is expressed in the correct SI units for acceleration. "
Force can be expressed as kg  m/s.,(A) true (B) false,B,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
Your weight equals your mass multiplied by the acceleration due to gravity.,(A) true (B) false,A,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
Any object that is accelerating is changing its speed.,(A) true (B) false,B,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
"If a balanced force acts on an object, the object will accelerate.",(A) true (B) false,B,"Whenever an object speeds up, slows down, or changes direction, it accelerates. Acceleration occurs whenever an unbalanced force acts on an object. Two factors affect the acceleration of an object: the net force acting on the object and the objects mass. Newtons second law of motion describes how force and mass affect acceleration. The law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Acceleration = or a = Net force Mass F m Q: While Tony races along on his rollerblades, what net force is acting on the skates? A: Tony exerts a backward force against the ground, as you can see in the Figure 1.1, first with one skate and then with the other. This force pushes him forward. Although friction partly counters the forward motion of the skates, it is weaker than the force Tony exerts. Therefore, there is a net forward force on the skates. "
A 10-kg object has greater acceleration due to gravity than a 5-kg object.,(A) true (B) false,B,"At Earths gravity, what is the weight in newtons of an object with a mass of 10 kg? At Earths gravity, 1 kg has a weight of 10 N. Therefore, 10 kg has a weight of (10 kg x 10 m/s2 ) = 100 N. "
The acceleration of an object equals its mass times the net force applied to it.,(A) true (B) false,B,"Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the objects mass. The relationships between these two factors and motion make up Newtons second law of motion. This law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Net force , or Mass F a= m Acceleration = You can watch a video about how Newtons second law of motion applies to football at this URL: http://science36 "
The acceleration of an object due to gravity depends on the objects initial velocity,(A) true (B) false,B,"Gravity is a force that pulls objects down toward the ground. When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls. In fact, its velocity increases by 9.8 m/s2, so by 1 second after an object starts falling, its velocity is 9.8 m/s. By 2 seconds after it starts falling, its velocity is 19.6 m/s (9.8 m/s + 9.8 m/s), and so on. The acceleration of a falling object due to gravity is illustrated in the Figure 1.1. Q: In this diagram, the boy drops the object at time t= 0 s. By t = 1 s, the object is falling at a velocity of 9.8 m/s. What is its velocity by t = 5 s? What will its velocity be at t = 6 s if it keeps falling? A: Its velocity at t = 5 s is 49.0 m/s, and at t = 6 s, it will be 58.8 m/s (49.0 m/s + 9.8 m/s). "
An object is accelerating when it,(A) speeds up (B) slows down (C) changes direction (D) any of the above,D,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
Newtons second law of motion relates an objects acceleration to,(A) its mass (B) its velocity (C) the net force acting on it (D) two of the above,D,"Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the objects mass. The relationships between these two factors and motion make up Newtons second law of motion. This law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Net force , or Mass F a= m Acceleration = You can watch a video about how Newtons second law of motion applies to football at this URL: http://science36 "
Doubling the net force acting on an object,(A) doubles its acceleration (B) decreases it acceleration (C) cuts its acceleration in half (D) does not affect its acceleration,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
"If you push a 20-kilogram mass with a force of 40 N, what will be the objects acceleration?",(A) 40 m/s2 (B) 20 m/s2 (C) 10 m/s2 (D) 2 m/s2,D,"The equation for acceleration given above can be used to calculate the acceleration of an object that is acted on by an unbalanced force. For example, assume you are pushing a large wooden trunk, like the one shown in Figure acceleration of the trunk, substitute these values in the equation for acceleration: a= F 20 N 2N = = m 10 kg kg Recall that one newton (1 N) is the force needed to cause a 1-kilogram mass to accelerate at 1 m/s2 . Therefore, force can also be expressed in the unit kgm/s2 . This way of expressing force can be substituted for newtons in the solution to the problem: a= 2 N 2 kg  m/s2 = = 2 m/s2 kg kg Why are there no kilograms in the final answer to this problem? The kilogram units in the numerator and denominator of the fraction cancel out. As a result, the answer is expressed in the correct units for acceleration: m/s2 . You Try It! Problem: Assume that you add the weights to the trunk in Figure 14.7. If you push the trunk and weights with a force of 20 N, what will be the trunks acceleration? Need more practice? You can find additional problems at this URL: "
Which units can be used to express force?,(A) N (B) kg/s2 (C) kg  m/s2 (D) two of the above,D,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
"If you know the mass of an object, you can calculate its weight with the formula",(A) F (B) F (C) F (D) F,C,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
"If the mass of an object doubles, its weight",(A) doubles (B) decreases (C) is not affected (D) changes by a factor of 21 ,A,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
acceleration due to gravity,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,G,"Gravity is a force that pulls objects down toward the ground. When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls. In fact, its velocity increases by 9.8 m/s2, so by 1 second after an object starts falling, its velocity is 9.8 m/s. By 2 seconds after it starts falling, its velocity is 19.6 m/s (9.8 m/s + 9.8 m/s), and so on. The acceleration of a falling object due to gravity is illustrated in the Figure 1.1. Q: In this diagram, the boy drops the object at time t= 0 s. By t = 1 s, the object is falling at a velocity of 9.8 m/s. What is its velocity by t = 5 s? What will its velocity be at t = 6 s if it keeps falling? A: Its velocity at t = 5 s is 49.0 m/s, and at t = 6 s, it will be 58.8 m/s (49.0 m/s + 9.8 m/s). "
formula for weight,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,F,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
formula for acceleration,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,D,"Calculating acceleration is complicated if both speed and direction are changing. Its easier to calculate acceleration when only speed is changing. To calculate acceleration without a change in direction, you just divide the change in velocity (represented by Dv) by the change in time (represented by Dt). The formula for acceleration in this case is: Acceleration = Dv Dt Consider this example. The cyclist in Figure 12.12 speeds up as he goes downhill on this straight trail. His velocity changes from 1 meter per second at the top of the hill to 6 meters per second at the bottom. If it takes 5 seconds for him to reach the bottom, what is his acceleration, on average, as he flies down the hill? Acceleration = Dv 6 m/s 1 m/s 5 m/s 1 m/s = = = = 1 m/s2 Dt 5s 5s 1m In words, this means that for each second the cyclist travels downhill, his velocity increases by 1 meter per second (on average). The answer to this problem is expressed in the SI unit for acceleration: m/s2 (""meters per second squared""). You Try It! Problem: Tranh slowed his skateboard as he approached the street. He went from 8 m/s to 2 m/s in a period of 3 seconds. What was his acceleration? "
measure of the force of gravity pulling on an object,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,B,"Weight measures the force of gravity pulling downward on an object. The SI unit for weight, like other forces, is the Newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 Newtons because of the pull of Earths gravity. On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale shown in the Figure 1.1. The scale measures the force with which gravity pulls an object downward. To delve a little deeper into weight and gravity, watch this video: Click image to the left or use the URL below. URL: "
type of relationship between acceleration and mass,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,E,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration is different. It is an inverse relationship. In an inverse relationship, when one variable increases, the other variable decreases. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Q: Tony has greater mass than the other two boys he is racing (pictured in the opening image). How will this affect his acceleration around the track? A: Tonys greater mass will result in less acceleration for the same amount of force. "
measure of the change in velocity of a moving object,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,A,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
type of relationship between acceleration and force,(A) acceleration (B) weight (C) direct relationship (D) a = (E) inverse relationship (F) F = m  a (G) 98 m/s2,C,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
Forces always act in pairs.,(A) true (B) false,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
What happens when a boater pushes against the water with an oar?,(A) The water pushes back (B) The boat moves in the opposite direction (C) The oar moves the boat (D) two of the above,D,"Flowing water slows down when it reaches flatter land or flows into a body of still water. What do you think happens then? The water starts dropping the particles it was carrying. As the water slows, it drops the largest particles first. The smallest particles settle out last. "
Action and reaction forces always cancel out.,(A) true (B) false,B,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
Action and reaction forces are not balanced because they,(A) are unequal in strength (B) act in the same direction (C) act on different objects (D) cancel each other out,C,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
Action and reaction forces always result in motion.,(A) true (B) false,B,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
An object has greater momentum if it has,(A) smaller size (B) greater mass (C) greater velocity (D) two of the above,D,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
Which statement about momentum is false?,(A) Momentum is a force (B) Momentum may be transferred (C) Momentum is always conserved (D) Momentum is a property only of moving objects,A,"Momentum is a property of a moving object that makes it hard to stop. The more mass it has or the faster its moving, the greater its momentum. Momentum equals mass times velocity and is represented by the equation: Momentum = Mass  Velocity Q: What is Codys momentum as he stands at the top of the ramp? A: Cody has no momentum as he stands there because he isnt moving. In other words, his velocity is zero. However, Cody will gain momentum as he starts moving down the ramp and picks up speed. Q: Codys older brother Jerod is pictured in the Figure 1.1. If Jerod were to travel down the ramp at the same velocity as Cody, who would have greater momentum? Who would be harder to stop? A: Jerod obviously has greater mass than Cody, so he would have greater momentum. He would also be harder to stop. "
Only moving objects have momentum.,(A) true (B) false,A,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
A smaller mass cannot have as much momentum as a larger mass.,(A) true (B) false,B,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. It would be easier for Lauren to push just one of her cousins on her skateboard than both of them. With just one twin, there would be only about half as much mass on the skateboard, so there would be less inertia to overcome. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
The momentum of a 50-kg object moving at a velocity of 2 m/s is,(A) 100 kg  m/s (B) 50 kg  m/s (C) 25 kg  m/s (D) 2 kg  m/s,A,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
Momentum can be transferred from one object to another.,(A) true (B) false,A,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
"When an action and reaction occur, momentum is usually lost.",(A) true (B) false,B,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
Momentum is conserved only in head-on collisions.,(A) true (B) false,B,"The Figure 1.1 shows how momentum is conserved in the two colliding skaters. The total momentum is the same after the collision as it was before. However, after the collision, skater 1 has more momentum and skater 2 has less momentum than before. Q: What if two skaters have a head-on collision? Do you think momentum is conserved then? A: As in all actions and reactions, momentum is also conserved in a head-on collision. "
Newtons third law of motion is also called the law of conservation of momentum.,(A) true (B) false,B,Newtons third law of motion is just one of many scientific laws. A scientific law is a statement describing what always happens under certain conditions. Other examples of laws in physical science include: Newtons first law of motion Newtons second law of motion Newtons law of universal gravitation Law of conservation of mass Law of conservation of energy Law of conservation of momentum 
Momentum is another term for acceleration.,(A) true (B) false,B,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
Momentum is a measure of an objects velocity.,(A) true (B) false,B,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
"If you double the velocity of an object, its momentum also doubles.",(A) true (B) false,A,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
The law of conservation of momentum applies to actions and reactions.,(A) true (B) false,A,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
"After two objects collide, their combined momentum is always zero.",(A) true (B) false,B,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
A bowling ball has greater momentum than a softball if both have the same velocity.,(A) true (B) false,A,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
how to calculate momentum,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,G,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
SI unit for momentum,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,D,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
equal and opposite forces that act on different objects,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,F,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
combined momentum of objects remains the same when an action-reaction occurs,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,E,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
property of a moving object that makes it hard to stop,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,A,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
equal and opposite forces that act on the same object,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,C,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
every action has an equal and opposite reaction,(A) momentum (B) Newtons third law of motion (C) balanced forces (D) kg  m/s (E) law of conservation of momentum (F) action-reaction forces (G) mass  velocity,B,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
"When an action force occurs, the reaction force is always",(A) in the same direction as the action force (B) equal and opposite to the action force (C) applied to the same object as the action force (D) two of the above,B,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
"When you stand on the floor, the force of your body pushing down on the floor is",(A) matched by the floor pushing up on your body (B) less than the reaction force applied by the floor (C) a reaction to the floor pushing up (D) none of the above,A,"More than one force may act on an object at the same time. In fact, just about all objects on Earth have at least two forces acting on them at all times. One force is gravity, which pulls objects down toward the center of Earth. The other force is an upward force that may be provided by the ground or other surface. Consider the example in Figure 13.3. A book is resting on a table. Gravity pulls the book downward with a force of 20 newtons. At the same time, the table pushes the book upward with a force of 20 newtons. The combined forces acting on the book  or any other object  are called the net force. This is the overall force acting on an object that takes into account all of the individual forces acting on the object. You can learn more about the concept of net force at this URL:  . "
"When a kangaroo jumps, the kangaroos action force acts on the ground and the reaction force",(A) is exerted by the ground (B) acts on the kangaroo (C) is greater than the action force (D) two of the above,D,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
"If the following objects are all moving at the same velocity, which of the objects has the greatest momentum?",(A) pea (B) marble (C) volleyball (D) bowling ball,D,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
Momentum is directly related to,(A) mass (B) velocity (C) distance (D) two of the above,D,"Momentum is a property of a moving object that makes it hard to stop. The more mass it has or the faster its moving, the greater its momentum. Momentum equals mass times velocity and is represented by the equation: Momentum = Mass  Velocity Q: What is Codys momentum as he stands at the top of the ramp? A: Cody has no momentum as he stands there because he isnt moving. In other words, his velocity is zero. However, Cody will gain momentum as he starts moving down the ramp and picks up speed. Q: Codys older brother Jerod is pictured in the Figure 1.1. If Jerod were to travel down the ramp at the same velocity as Cody, who would have greater momentum? Who would be harder to stop? A: Jerod obviously has greater mass than Cody, so he would have greater momentum. He would also be harder to stop. "
Momentum is a,(A) force of nature (B) form of energy (C) property of an object (D) measure of an objects motion,C,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
What is the momentum of a 9-kilogram object that has a velocity of 3 m/s?,(A) 3 kg/m/s (B) 6 kg/s/m (C) 12 kg  s/m (D) 27 kg  m/s,D,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
Only liquids have buoyancy.,(A) true (B) false,B,"Density, or the amount of mass in a given volume, is also related to buoyancy. Thats because density affects weight. A given volume of a denser substance is heavier than the same volume of a less dense substance. For example, ice is less dense than liquid water. This explains why ice cubes float in a glass of water. This and other examples of density and buoyant force are illustrated in Figure 15.14 and in the video at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Which statement is true about weight and buoyant force?,(A) They work in opposite directions (B) They are always equal in strength (C) They determine whether an object floats (D) two of the above,D,"Weight is a measure of the force of gravity pulling down on an object. Buoyant force pushes up on an object. Weight and buoyant force together determine whether an object sinks or floats. This is illustrated in Figure 15.13. If an objects weight is the same as the buoyant force acting on the object, then the object floats. This is the example on the left in Figure 15.13. If an objects weight is greater than the buoyant force acting on the object, then the object sinks. This is the example on the right in Figure 15.13. Because of buoyant force, objects seem lighter in water. You may have noticed this when you went swimming and could easily pick up a friend or sibling under the water. Some of the persons weight was countered by the buoyant force of the water. "
Any object sinks if its weight is greater than its volume,(A) true (B) false,B,"Weight is a measure of the force of gravity pulling down on an object. Buoyant force pushes up on an object. Weight and buoyant force together determine whether an object sinks or floats. This is illustrated in Figure 15.13. If an objects weight is the same as the buoyant force acting on the object, then the object floats. This is the example on the left in Figure 15.13. If an objects weight is greater than the buoyant force acting on the object, then the object sinks. This is the example on the right in Figure 15.13. Because of buoyant force, objects seem lighter in water. You may have noticed this when you went swimming and could easily pick up a friend or sibling under the water. Some of the persons weight was countered by the buoyant force of the water. "
Some objects float in water because the objects,(A) weigh less than the weight of the water they displace (B) have less mass when they are placed in water (C) have greater density than water (D) have the property of buoyancy,A,Objects such as ships may float in a fluid like water because of buoyant force. This is an upward force that a fluid exerts on any object that is placed in it. Archimedes discovered that the buoyant force acting on an object equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Archimedes principle). 
A denser object weighs more than a less dense object of the same size.,(A) true (B) false,A,"You are going to visit a friend. You fill one backpack with books so you can study later. You stuff your pillow into another backpack that is the same size. Which backpack will be easier to carry? Even though the backpacks are the same size, the bag that contains your books is going to be much heavier. It has a greater density than the backpack with your pillow. Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Mass is a measure of the amount of matter in an object. The amount of space an object takes up is described by its volume. The density of an object depends on its mass and its volume. Density can be calculated using the following equation: Density = Mass/Volume Samples that are the same size, but have different densities, will have different masses. Gold has a density of about 19 g/cm3 . Pyrite has a density of only about 5 g/cm3 . Quartz is even less dense than pyrite, and has a density of 2.7 g/cm3 . If you picked up a piece of pyrite and a piece of quartz that were the same size, the pyrite would seem almost twice as heavy as the quartz. "
The amount of water that is displaced when you submerge yourself in a swimming pool is equal to your bodys,(A) surface area (B) volume (C) weight (D) mass,B,"Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. Q: If you jump into swimming pool, how much water does your body displace? A: The water displaced by your body is equal to your bodys volume. Depending on your size, this volume might be about 0.07 m3 . "
The weight of the displaced water in question 3 equals the,(A) force of gravity acting on your body (B) buoyant force acting on your body (C) weight of your body (D) two of the above,B,"Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. Q: If you jump into swimming pool, how much water does your body displace? A: The water displaced by your body is equal to your bodys volume. Depending on your size, this volume might be about 0.07 m3 . "
Helium balloons float in air because helium is purer than air.,(A) true (B) false,B,"Did you ever get a birthday balloon like the one pictured 1.2? The balloon is filled with the noble gas helium. The gas is pumped from a tank into a Mylar balloon. Unlike a balloon filled with air, a balloon filled with helium needs to be weighted down so it wont float away. Q: Why does a helium balloon float away if its not weighted down? A: Helium atoms have just two protons, two neutrons, and two electrons, so they have less mass than any other atoms except hydrogen. As a result, helium is lighter than air, explaining why a helium balloon floats up into the air unless weighted down. Early incandescent light bulbs, like the one pictured in the Figure 1.3, didnt last very long. The filaments quickly burned out. Although air was pumped out of the bulb, it wasnt a complete vacuum. Oxygen in the small amount of air remaining inside the light bulb reacted with the metal filament. This corroded the filament and caused dark deposits on the glass. Filling a light bulb with argon gas prevents these problems. Thats why modern light bulbs are filled with argon. A: As a noble gas with eight electrons, argon doesnt react with the metal in the filament. This protects the filament and keeps the glass blub free of deposits. Noble gases are also used to fill the glass tubes of lighted signs like the one in the Figure 1.4. Although noble gases are chemically nonreactive, their electrons can be energized by sending an electric current through them. When this happens, the electrons jump to a higher energy level. When the electrons return to their original energy level, they give off energy as light. Different noble gases give off light of different colors. Neon gives off reddish-orange light, like the word Open in the sign below. Krypton gives off violet light and xenon gives off blue light. "
The buoyant force acting on an object in a fluid always equals the objects weight.,(A) true (B) false,B,"Weight is a measure of the force of gravity pulling down on an object. Buoyant force pushes up on an object. Weight and buoyant force together determine whether an object sinks or floats. This is illustrated in Figure 15.13. If an objects weight is the same as the buoyant force acting on the object, then the object floats. This is the example on the left in Figure 15.13. If an objects weight is greater than the buoyant force acting on the object, then the object sinks. This is the example on the right in Figure 15.13. Because of buoyant force, objects seem lighter in water. You may have noticed this when you went swimming and could easily pick up a friend or sibling under the water. Some of the persons weight was countered by the buoyant force of the water. "
What happens if an object is placed in water and its density is greater than water?,(A) The object always sinks (B) The object always floats (C) The object may sink or float (D) The objects density decreases,C,"Density, or the amount of mass in a given volume, is also related to the ability of an object to float. Thats because density affects weight. A given volume of a denser substance is heavier than the same volume of a less dense substance. For example, ice is less dense than liquid water. This explains why the giant ice berg in the Figure 1.3 is floating in the ocean. Q: Can you think of more examples of substances that float in a fluid because they are low in density? A: Oil is less dense than water, so oil from a spill floats on ocean water. Helium is less dense than air, so balloons filled with helium float in air. "
Archimedes determined that the mass of fluid displaced by an object equals the mass of the object.,(A) true (B) false,B,"Did you ever notice that when you get into a bathtub of water the level of the water rises? More than 2200 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. What does displacement have to do with buoyant force? Everything! Archimedes discovered that the buoyant force acting on an object in a fluid equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Archimedes Principle). Archimedes law explains why some objects float in fluids even though they are very heavy. Remember the oil tanker that opened this chapter? It is extremely heavy, yet it stays afloat. If a steel ball with the same weight as the ship were put into water, it would sink to the bottom (see Figure 15.15). Thats because the volume of water displaced by the steel ball weighs less than the ball. As a result, the buoyant force is not as great as the force of gravity acting on the ball. The design of the ships hull, on the other hand, causes it to displace much more water than the ball. In fact, the weight of the displaced water is greater than the weight of the ship, so the buoyant force is greater than the force of gravity acting on the ship. As a result, the ship floats. You can check your understanding of Archimedes law by doing the brainteaser at this URL:  . For an entertaining video presentation of Archimedes law, go to this URL: http://videos.howstuffworks.com/disc "
"The more fluid an object displaces, the greater the buoyant force acting on the object.",(A) true (B) false,A,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
Buoyancy is a property of an object that can float in a fluid.,(A) true (B) false,B,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
Fluids exert pressure only in an upward direction.,(A) true (B) false,B,"Two factors influence the pressure of fluids. They are the depth of the fluid and its density. A fluid exerts more pressure at greater depths. Deeper in a fluid, all of the fluid above it results in more weight pressing down. This causes greater pressure the deeper you go. Denser fluids such as water exert more pressure than less dense fluids such as air. The particles of denser fluids are closer together, so there are more collisions of particles in a given area. The difference in density of water and air is illustrated in the Figure 1.3. "
Buoyant force explains why some objects float in water.,(A) true (B) false,A,"Buoyant force is an upward force that fluids exert on any object that is placed in them. The ability of fluids to exert this force is called buoyancy. What explains buoyant force? A fluid exerts pressure in all directions, but the pressure is greater at greater depth. Therefore, the fluid below an object, where the fluid is deeper, exerts greater pressure on the object than the fluid above it. You can see in the Figure 1.1 how this works. Buoyant force explains why the girl pictured above can float in water. Q: Youve probably noticed that some things dont float in water. For example, if you drop a stone in water, it will sink to the bottom rather than floating. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? A: The answer has to do with their weight. "
Objects float because fluids exert only upward pressure.,(A) true (B) false,B,"Buoyant force is an upward force that fluids exert on any object that is placed in them. The ability of fluids to exert this force is called buoyancy. What explains buoyant force? A fluid exerts pressure in all directions, but the pressure is greater at greater depth. Therefore, the fluid below an object, where the fluid is deeper, exerts greater pressure on the object than the fluid above it. You can see in the Figure 1.1 how this works. Buoyant force explains why the girl pictured above can float in water. Q: Youve probably noticed that some things dont float in water. For example, if you drop a stone in water, it will sink to the bottom rather than floating. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? A: The answer has to do with their weight. "
amount of mass in a given volume,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,G,"The density of matter is actually the amount of matter in a given space. The amount of matter is measured by its mass. The space matter takes up is measured by its volume. Therefore, the density of matter can be calculated with this formula: Density = mass volume Assume, for example, that a book has a mass of 500 g and a volume of 1000 cm3 . Then the density of the book is: Density = 500 g = 0.5 g/cm3 1000 cm3 Q: What is the density of a liquid that has a volume of 30 mL and a mass of 300 g? A: The density of the liquid is: Density = 300 g = 10 g/mL 30 mL "
Buoyancy is a property of some objects when placed in fluids.,(A) true (B) false,B,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
force that causes an object to sink in a fluid,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,F,"Buoyant force is an upward force that fluids exert on any object that is placed in them. The ability of fluids to exert this force is called buoyancy. What explains buoyant force? A fluid exerts pressure in all directions, but the pressure is greater at greater depth. Therefore, the fluid below an object, where the fluid is deeper, exerts greater pressure on the object than the fluid above it. You can see in the Figure 1.1 how this works. Buoyant force explains why the girl pictured above can float in water. Q: Youve probably noticed that some things dont float in water. For example, if you drop a stone in water, it will sink to the bottom rather than floating. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? A: The answer has to do with their weight. "
to remain at or near the surface of a fluid,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,D,"Ocean water is an example of a liquid. A liquid is matter that has a fixed volume but not a fixed shape. Instead, a liquid takes the shape of its container. If the volume of a liquid is less than the volume of its container, the top surface will be exposed to the air, like the oil in the bottles in Figure 4.4. Two interesting properties of liquids are surface tension and viscosity. Surface tension is a force that pulls particles at the exposed surface of a liquid toward other liquid particles. Surface tension explains why water forms droplets, like those in Figure 4.5. Viscosity is a liquids resistance to flowing. Thicker liquids are more viscous than thinner liquids. For example, the honey in Figure 4.5 is more viscous than the vinegar. You can learn more about surface tension and viscosity at these URLs: http://io9.com/5668221/an-experiment-with-soap-water-pepper-and-surface-tension http://chemed.chem.wisc.edu/chempaths/GenChem-Textbook/Viscosity-840.html  (1:40) MEDIA Click image to the left or use the URL below. URL: "
"If two objects have the same volume but differ in density, the denser object will weigh more.",(A) true (B) false,A,"You are going to visit a friend. You fill one backpack with books so you can study later. You stuff your pillow into another backpack that is the same size. Which backpack will be easier to carry? Even though the backpacks are the same size, the bag that contains your books is going to be much heavier. It has a greater density than the backpack with your pillow. Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Mass is a measure of the amount of matter in an object. The amount of space an object takes up is described by its volume. The density of an object depends on its mass and its volume. Density can be calculated using the following equation: Density = Mass/Volume Samples that are the same size, but have different densities, will have different masses. Gold has a density of about 19 g/cm3 . Pyrite has a density of only about 5 g/cm3 . Quartz is even less dense than pyrite, and has a density of 2.7 g/cm3 . If you picked up a piece of pyrite and a piece of quartz that were the same size, the pyrite would seem almost twice as heavy as the quartz. "
force that causes an object to float on a fluid,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,A,Objects such as ships may float in a fluid like water because of buoyant force. This is an upward force that a fluid exerts on any object that is placed in it. Archimedes discovered that the buoyant force acting on an object equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Archimedes principle). 
Archimedes law explains why heavy objects can float if they displace enough water.,(A) true (B) false,A,"Archimedes law explains why some objects float in fluids even though they are very heavy. It all depends on how much fluid they displace. The cruise ship pictured in the opening image is extremely heavy, yet it stays afloat. If a steel ball with the same weight as the ship were placed in water, it would sink to the bottom. This is modeled in the Figure 1.1. The reason the ball sinks is that its shape is very compact, so it displaces relatively little water. The volume of water displaced by the steel ball weighs less than the ball itself, so the buoyant force is not as great as the force of gravity pulling down on the ball. Thus, the ball sinks. Now look at the ships hull in the Figure 1.1. Its shape causes the ship to displace much more water than the ball. In fact, the weight of the displaced water is greater than the weight of the ship. As a result, the buoyant force is greater than the force of gravity acting on the ship, so the ship floats. Q: Why might you be more likely to float in water if you stretch out your body rather than curl up into a ball? A: You would displace more water by stretching out your body, so there would be more buoyant force acting on it. Therefore, you would be more likely to float in this position. "
The buoyant force acting on an object in a fluid depends on the total volume of the fluid.,(A) true (B) false,B,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
act in which an object moves fluid out of its way,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,B,"Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your hand and the water. When a skydiver is falling toward Earth with a parachute, fluid friction between the parachute and the air slows the descent (see Figure 13.14). Fluid pressure with the air is called air resistance. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. The very large surface area of a parachute, for example, has greater air resistance than a skydivers body. "
ability of a fluid to exert upward force,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,C,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
measure of the force of gravity pulling down on an object,(A) buoyant force (B) displacement (C) buoyancy (D) float (E) weight (F) gravity (G) density,E,"Weight measures the force of gravity pulling downward on an object. The SI unit for weight, like other forces, is the Newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 Newtons because of the pull of Earths gravity. On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale shown in the Figure 1.1. The scale measures the force with which gravity pulls an object downward. To delve a little deeper into weight and gravity, watch this video: Click image to the left or use the URL below. URL: "
Which statement explains buoyant force?,(A) Denser fluids exert less pressure (B) Fluid pressure is greater at greater depths (C) An object weighs less in water (D) all of the above,B,"Buoyant force is an upward force that fluids exert on any object that is placed in them. The ability of fluids to exert this force is called buoyancy. What explains buoyant force? A fluid exerts pressure in all directions, but the pressure is greater at greater depth. Therefore, the fluid below an object, where the fluid is deeper, exerts greater pressure on the object than the fluid above it. You can see in the Figure 1.1 how this works. Buoyant force explains why the girl pictured above can float in water. Q: Youve probably noticed that some things dont float in water. For example, if you drop a stone in water, it will sink to the bottom rather than floating. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? A: The answer has to do with their weight. "
What determines whether an object floats or sinks in water?,(A) the buoyant force acting on the object (B) the force of gravity acting on the object (C) the objects weight (D) all of the above,D,"Weight is a measure of the force of gravity pulling down on an object, whereas buoyant force pushes up on an object. Which force is greater determines whether an object sinks or floats. Look at the Figure 1.2. On the left, the objects weight is the same as the buoyant force acting on it, so the object floats. On the right, the objects weight is greater than the buoyant force acting on it, so the object sinks. "
Ice cubes float on water because ice is,(A) less dense than water (B) colder than water (C) heavier than water (D) less stable than water,A,"Density, or the amount of mass in a given volume, is also related to the ability of an object to float. Thats because density affects weight. A given volume of a denser substance is heavier than the same volume of a less dense substance. For example, ice is less dense than liquid water. This explains why the giant ice berg in the Figure 1.3 is floating in the ocean. Q: Can you think of more examples of substances that float in a fluid because they are low in density? A: Oil is less dense than water, so oil from a spill floats on ocean water. Helium is less dense than air, so balloons filled with helium float in air. "
"When you sit in a tub of bath water, the water rises because it",(A) becomes less dense (B) is displaced (C) gets warmer (D) floats,B,"Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. Q: If you jump into swimming pool, how much water does your body displace? A: The water displaced by your body is equal to your bodys volume. Depending on your size, this volume might be about 0.07 m3 . "
Buoyancy is a property of,(A) gases (B) liquids (C) solids (D) two of the above,D,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
Where is water pressure greatest on an object in the water?,(A) on top of the object (B) on the sides of the object (C) on the bottom of the object (D) two of the above,C,"Pressure is the amount of force acting on a given area. As you go deeper in the ocean, the pressure exerted by the water increases steadily. Thats because there is more and more water pressing down on you from above. The Figure 1.1 shows how pressure changes with depth. For each additional meter below the surface, pressure increases by 10 kPa. At 30 meters below the surface, the pressure is double the pressure at the surface. At a depth greater than 500 meters, the pressure is too great for humans to withstand without special equipment to protect them. At nearly 11,000 meters below the surface, the pressure is tremendous. "
You feel lighter in the water than on land because,(A) gravity is not as strong in the water (B) the buoyant force of the water counters some of your weight (C) your mass is less in the water than on land (D) you are trying to stay afloat,B,"Archimedes law explains why some objects float in fluids even though they are very heavy. It all depends on how much fluid they displace. The cruise ship pictured in the opening image is extremely heavy, yet it stays afloat. If a steel ball with the same weight as the ship were placed in water, it would sink to the bottom. This is modeled in the Figure 1.1. The reason the ball sinks is that its shape is very compact, so it displaces relatively little water. The volume of water displaced by the steel ball weighs less than the ball itself, so the buoyant force is not as great as the force of gravity pulling down on the ball. Thus, the ball sinks. Now look at the ships hull in the Figure 1.1. Its shape causes the ship to displace much more water than the ball. In fact, the weight of the displaced water is greater than the weight of the ship. As a result, the buoyant force is greater than the force of gravity acting on the ship, so the ship floats. Q: Why might you be more likely to float in water if you stretch out your body rather than curl up into a ball? A: You would displace more water by stretching out your body, so there would be more buoyant force acting on it. Therefore, you would be more likely to float in this position. "
unit for power that equals 745 watts,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,B,"The rate at which a device changes electric current to another form of energy is called electric power. The SI unit for powerincluding electric poweris the watt. A watt equals 1 joule of energy per second. High wattages are often expressed in kilowatts, where 1 kilowatt equals 1000 watts. The power of an electric device, such as a hair dryer, can be calculated if you know the voltage of the circuit and how much current the device receives. The following equation is used: Power (watts) = Current (amps)  Voltage (volts) Assume that Mirandas hair dryer is the only electric device in a 120-volt circuit that carries 15 amps of current. Then the power of her hair dryer in kilowatts is: Power = 15 amps  120 volts = 1800 watts, or 1.8 kilowatts Q: If a different hair dryer is plugged into a 120-volt circuit that carries 10 amps of current. What is the power of the other hair dryer? A: Substitute these values in the power equation: Power = 10 amps  120 volts = 1200 watts, or 1.2 kilowatts "
"Assume that a friend hands you a 15-newton box to hold for her. If you hold the box without moving it at a height of 1.5 meters above the ground, how much work do you do?",(A) 225 J (B) 15 J (C) 10 J (D) none of the above,D,"The equation for work given above can be used to calculate the amount of work that is done if force and distance are known. For example, assume that one of the weight lifters in Figure 16.2 lifts a weight of 400 newtons over his head to a height of 2.2 meters off the ground. The amount of work he does is: Work = 400 N  2.2 m = 880 N  m Notice that the unit for work is the newton  meter. This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 newton of force moves an object over a distance of 1 meter. Problem Solving Problem: Todd pushed a 500 N box 4 meters across the floor. How much work did he do? Solution: Use the equation Work = Force  Distance. Work = 500 N  4 m = 2000 N  m, or 2000 J You Try It! Problem: Lara lifted a 100 N box 1.5 meters above the floor. How much work did she do? "
SI unit for work,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,A,"The equation for work can be used to calculate work if force and distance are known. To use the equation, force is expressed in Newtons (N), and distance is expressed in meters (m). For example, assume that Clarissa uses 100 Newtons of force to push the mower and that she pushes it for a total of 200 meters as she cuts the grass in her grandmothers yard. Then, the amount of work Clarissa does is: Work = 100 N  200 m = 20,000 N  m Notice that the unit for work in the answer is the Newton  meter (N  m). This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 N of force moves an object over a distance of 1 m. Q: After Clarissa mows her grandmothers lawn, she volunteers to mow a neighbors lawn as well. If she pushes the mower with the same force as before and moves it over a total of 234 meters, how much work does she do mowing the neighbors lawn? A: The work Clarissa does can be calculated as: Work = 100 N  234 m = 23,400 N  m, or 23,400 J "
Which weight lifter described below does the most work?,(A) Tom lifts 195 N a distance of 20 m (B) Ted lifts 190 N a distance of 21 m (C) Tad lifts 185 N a distance of 22 m (D) Tim lifts 180 N a distance of 23 m,D,"Work is directly related to both the force applied to an object and the distance the object moves. It can be represented by the equation: Work = Force  Distance This equation shows that the greater the force that is used to move an object or the farther the object is moved, the more work that is done. To see the effects of force and distance on work, compare the weight lifters in the Figure 1.2. The two weight lifters on the left are lifting the same amount of weight, but the one on the bottom is lifting the weight a greater distance. Therefore, this weight lifter is doing more work. The two weight lifters on the bottom right are both lifting the weight the same distance, but the weight lifter on the left is lifting a heavier weight, so she is doing more work. "
how to calculate work,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,D,"You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 1000-watt microwave oven for 20 seconds, how much work does it do? First express 1000 watts in J/s and then substitute this value for power the work equation: Work = 1000 J/s  20 s = 20,000 J "
Another way of writing 1 joule is,(A) 1 N  m (B) 1 N/m (C) 1 N  m2  (D) 1 N/m2 ,A,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
One horsepower is about equal to,(A) 1 watt (B) 75 watts (C) 745 watts (D) 1 kilowatt,C,"Sometimes power is measured in a unit called the horsepower. For example, the power of car engines is usually expressed in horsepowers. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. Compare the horsepowers in the Figure 1.2 to the other Figure 1.3. This team of three horses provides 3 horsepowers of power. This big tractor provides 180 horsepowers of power. Q: If the team of horses and the tractor do the same amount of work plowing a field, which will get the job done faster? A: The tractor will get the job done faster because it has more power. In fact, because the tractor has 30 times the power of the six-horse team, ideally it can do the same work 30 times faster! "
use of force to move an object,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,G,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
how to calculate power,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,F,"Power can be calculated using the formula above, if the amount of work and time are known. For example, assume that a small engine does 3000 joules of work in 2 seconds. Then the power of the motor is: Power = 3000 J = 1500 J/s, or 1500 W 2s You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 2000-watt hair dryer for 30 seconds, how much work is done? First express 2000 watts in J/s and then substitute this value for power in the work equation: Work = 2000 J/s  30 s = 60, 000 J For a video presentation on calculating power and work, go to this link:  Problem Solving Problem: An electric mixer does 2500 joules of work in 5 seconds. What is its power? Solution: Use the equation: Power = Work Time . Power = 2500 J = 500 J/s, or 500 W 5s You Try It! Problem: How much work can be done in 30 seconds by a 1000-watt microwave? "
How much work is done by a 1000-watt hairdryer in 40 seconds?,(A) 04 J (B) 25 J (C) 960 J (D) 40 (E) 000 J,D,"Power can be calculated using the formula above, if the amount of work and time are known. For example, assume that a small engine does 3000 joules of work in 2 seconds. Then the power of the motor is: Power = 3000 J = 1500 J/s, or 1500 W 2s You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 2000-watt hair dryer for 30 seconds, how much work is done? First express 2000 watts in J/s and then substitute this value for power in the work equation: Work = 2000 J/s  30 s = 60, 000 J For a video presentation on calculating power and work, go to this link:  Problem Solving Problem: An electric mixer does 2500 joules of work in 5 seconds. What is its power? Solution: Use the equation: Power = Work Time . Power = 2500 J = 500 J/s, or 500 W 5s You Try It! Problem: How much work can be done in 30 seconds by a 1000-watt microwave? "
SI unit for power,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,E,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules and time is measured in seconds, so power is expressed in joules per second (J/s). This is the SI unit for work, also known as the watt (W). A watt equals 1 joule of work per second. The watt is named for James Watt, a Scottish inventor you will read about below. You may already be familiar with watts. Thats because light bulbs and small appliances such as hair dryers are labeled with the watts of power they provide. For example, the hair dryer in Figure 16.5 is labeled ""2000 watts."" This amount of power could also be expressed kilowatts. A kilowatt equals 1000 watts, so the 2000-watt hair dryer produces 2 kilowatts of power. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave, a high-power microwave can cook more food in the same time or the same amount of food in less time. "
measure of the amount of work that can be done in a given amount of time,(A) joule (B) horsepower (C) power (D) force  distance (E) watt (F) work  time (G) work,C,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules and time is measured in seconds, so power is expressed in joules per second (J/s). This is the SI unit for work, also known as the watt (W). A watt equals 1 joule of work per second. The watt is named for James Watt, a Scottish inventor you will read about below. You may already be familiar with watts. Thats because light bulbs and small appliances such as hair dryers are labeled with the watts of power they provide. For example, the hair dryer in Figure 16.5 is labeled ""2000 watts."" This amount of power could also be expressed kilowatts. A kilowatt equals 1000 watts, so the 2000-watt hair dryer produces 2 kilowatts of power. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave, a high-power microwave can cook more food in the same time or the same amount of food in less time. "
Every time you apply a force you do work,(A) true (B) false,B,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isnt moving anything, so she isnt doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure 1.1 illustrates this point. Q: If the box the man is carrying is very heavy, does he do any work as he walks across the room with it? A: Regardless of the weight of the box, the man does no work on it as he holds it while walking across the room. However, he does more work when he first lifts a heavier box to chest height. "
A more powerful device can do more work in the same amount of time than a less powerful device.,(A) true (B) false,A,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules (J) and time is measured in seconds (s), so power is expressed in joules per second (J/s). This is the SI unit for power, also known as the watt (W). A watt equals 1 joule of work per second. Youre probably already familiar with watts. Light bulbs and small appliances such as microwave ovens are labeled with the watts of power they provide. For example, the package of light bulbs in the Figure 1.1 is labeled 14 watts. Q: Assume you have two light bulbs of the same type, such as two compact fluorescent light bulbs like the one pictured in the Figure 1.1. If one light bulb is a 25-watt bulb and the other is a 60-watt bulb, which bulb produces brighter light? A: The 60-watt bulb is more powerful, so it produces brighter light. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave oven, a high-power microwave oven can cook more food in the same time or the same amount of food in less time. "
The power of a machine equals the work it does multiplied by the time it takes to do that work.,(A) true (B) false,B,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
The steam engine invented by James Watt had the power of one horse.,(A) true (B) false,B,"Sometimes power is measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. The horsepower was introduced by James Watt, who invented the first powerful steam engine in the 1770s. Watts steam engine led to a revolution in industry and agriculture because of its power. Watt wanted to impress people with the power of his steam engine, so he compared it with something familiar to people of his time: the power of workhorses, like those pictured in Figure 16.6. Watt said his steam engine could produce the power of 20 horses, or 20 horsepower. The most powerful engines today may produce more than 100,000 horsepower! How many watts of power is that? "
"The most powerful engines today can produce more than 100,000 horsepowers.",(A) true (B) false,A,"Sometimes power is measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. The horsepower was introduced by James Watt, who invented the first powerful steam engine in the 1770s. Watts steam engine led to a revolution in industry and agriculture because of its power. Watt wanted to impress people with the power of his steam engine, so he compared it with something familiar to people of his time: the power of workhorses, like those pictured in Figure 16.6. Watt said his steam engine could produce the power of 20 horses, or 20 horsepower. The most powerful engines today may produce more than 100,000 horsepower! How many watts of power is that? "
Whenever you move your body you are doing work.,(A) true (B) false,A,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isnt moving anything, so she isnt doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure 1.1 illustrates this point. Q: If the box the man is carrying is very heavy, does he do any work as he walks across the room with it? A: Regardless of the weight of the box, the man does no work on it as he holds it while walking across the room. However, he does more work when he first lifts a heavier box to chest height. "
You do work when you push a heavy object even if the object does not move.,(A) true (B) false,B,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isnt moving anything, so she isnt doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure 1.1 illustrates this point. Q: If the box the man is carrying is very heavy, does he do any work as he walks across the room with it? A: Regardless of the weight of the box, the man does no work on it as he holds it while walking across the room. However, he does more work when he first lifts a heavier box to chest height. "
Work can be expressed in the unit N  m.,(A) true (B) false,A,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
A more powerful device can do the same work in less time than a less powerful device.,(A) true (B) false,A,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules (J) and time is measured in seconds (s), so power is expressed in joules per second (J/s). This is the SI unit for power, also known as the watt (W). A watt equals 1 joule of work per second. Youre probably already familiar with watts. Light bulbs and small appliances such as microwave ovens are labeled with the watts of power they provide. For example, the package of light bulbs in the Figure 1.1 is labeled 14 watts. Q: Assume you have two light bulbs of the same type, such as two compact fluorescent light bulbs like the one pictured in the Figure 1.1. If one light bulb is a 25-watt bulb and the other is a 60-watt bulb, which bulb produces brighter light? A: The 60-watt bulb is more powerful, so it produces brighter light. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave oven, a high-power microwave oven can cook more food in the same time or the same amount of food in less time. "
"If you move an object that weighs 10 newtons a distance of 2 meters, you do 5 joules of work.",(A) true (B) false,B,"The equation for work given above can be used to calculate the amount of work that is done if force and distance are known. For example, assume that one of the weight lifters in Figure 16.2 lifts a weight of 400 newtons over his head to a height of 2.2 meters off the ground. The amount of work he does is: Work = 400 N  2.2 m = 880 N  m Notice that the unit for work is the newton  meter. This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 newton of force moves an object over a distance of 1 meter. Problem Solving Problem: Todd pushed a 500 N box 4 meters across the floor. How much work did he do? Solution: Use the equation Work = Force  Distance. Work = 500 N  4 m = 2000 N  m, or 2000 J You Try It! Problem: Lara lifted a 100 N box 1.5 meters above the floor. How much work did she do? "
"If you move the object in question 5 a distance of 5 meters, you do 2 joules of work.",(A) true (B) false,B,"The equation for work given above can be used to calculate the amount of work that is done if force and distance are known. For example, assume that one of the weight lifters in Figure 16.2 lifts a weight of 400 newtons over his head to a height of 2.2 meters off the ground. The amount of work he does is: Work = 400 N  2.2 m = 880 N  m Notice that the unit for work is the newton  meter. This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 newton of force moves an object over a distance of 1 meter. Problem Solving Problem: Todd pushed a 500 N box 4 meters across the floor. How much work did he do? Solution: Use the equation Work = Force  Distance. Work = 500 N  4 m = 2000 N  m, or 2000 J You Try It! Problem: Lara lifted a 100 N box 1.5 meters above the floor. How much work did she do? "
A device that does 100 joules of work in 3 seconds has 300 watts of power.,(A) true (B) false,B,"Power can be calculated using the formula above, if the amount of work and time are known. For example, assume that a small engine does 3000 joules of work in 2 seconds. Then the power of the motor is: Power = 3000 J = 1500 J/s, or 1500 W 2s You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 2000-watt hair dryer for 30 seconds, how much work is done? First express 2000 watts in J/s and then substitute this value for power in the work equation: Work = 2000 J/s  30 s = 60, 000 J For a video presentation on calculating power and work, go to this link:  Problem Solving Problem: An electric mixer does 2500 joules of work in 5 seconds. What is its power? Solution: Use the equation: Power = Work Time . Power = 2500 J = 500 J/s, or 500 W 5s You Try It! Problem: How much work can be done in 30 seconds by a 1000-watt microwave? "
The unit called the horsepower was introduced by James Watt.,(A) true (B) false,A,"Sometimes power is measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. The horsepower was introduced by James Watt, who invented the first powerful steam engine in the 1770s. Watts steam engine led to a revolution in industry and agriculture because of its power. Watt wanted to impress people with the power of his steam engine, so he compared it with something familiar to people of his time: the power of workhorses, like those pictured in Figure 16.6. Watt said his steam engine could produce the power of 20 horses, or 20 horsepower. The most powerful engines today may produce more than 100,000 horsepower! How many watts of power is that? "
A 2-horsepower device has almost 1500 watts of power.,(A) true (B) false,A,"Sometimes power is measured in a unit called the horsepower. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. The horsepower was introduced by James Watt, who invented the first powerful steam engine in the 1770s. Watts steam engine led to a revolution in industry and agriculture because of its power. Watt wanted to impress people with the power of his steam engine, so he compared it with something familiar to people of his time: the power of workhorses, like those pictured in Figure 16.6. Watt said his steam engine could produce the power of 20 horses, or 20 horsepower. The most powerful engines today may produce more than 100,000 horsepower! How many watts of power is that? "
"The more force you apply to move an object, the more work you do.",(A) true (B) false,A,"Work is directly related to both the force applied to an object and the distance the object moves. It can be represented by the equation: Work = Force  Distance This equation shows that the greater the force that is used to move an object or the farther the object is moved, the more work that is done. To see the effects of force and distance on work, compare the weight lifters in the Figure 1.2. The two weight lifters on the left are lifting the same amount of weight, but the one on the bottom is lifting the weight a greater distance. Therefore, this weight lifter is doing more work. The two weight lifters on the bottom right are both lifting the weight the same distance, but the weight lifter on the left is lifting a heavier weight, so she is doing more work. "
"For work to be done on an object, force must be applied",(A) in an upward direction (B) against the force of gravity (C) in the same direction as gravity (D) in the same direction that the object moves,D,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
Work is directly related to the force applied to an object and to the,(A) mass of the object (B) distance the object moves (C) direction of the applied force (D) amount of time the force is applied,B,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
"If a mover pushes a box weighing 100 newtons a distance of 3 meters, how much work does she do?",(A) 3J (B) 33 J (C) 300 J (D) 3000 J,C,"The equation for work given above can be used to calculate the amount of work that is done if force and distance are known. For example, assume that one of the weight lifters in Figure 16.2 lifts a weight of 400 newtons over his head to a height of 2.2 meters off the ground. The amount of work he does is: Work = 400 N  2.2 m = 880 N  m Notice that the unit for work is the newton  meter. This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 newton of force moves an object over a distance of 1 meter. Problem Solving Problem: Todd pushed a 500 N box 4 meters across the floor. How much work did he do? Solution: Use the equation Work = Force  Distance. Work = 500 N  4 m = 2000 N  m, or 2000 J You Try It! Problem: Lara lifted a 100 N box 1.5 meters above the floor. How much work did she do? "
The power of a device can be expressed in,(A) joules (B) joules per meter (C) joules per second (D) none of the above,C,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules and time is measured in seconds, so power is expressed in joules per second (J/s). This is the SI unit for work, also known as the watt (W). A watt equals 1 joule of work per second. The watt is named for James Watt, a Scottish inventor you will read about below. You may already be familiar with watts. Thats because light bulbs and small appliances such as hair dryers are labeled with the watts of power they provide. For example, the hair dryer in Figure 16.5 is labeled ""2000 watts."" This amount of power could also be expressed kilowatts. A kilowatt equals 1000 watts, so the 2000-watt hair dryer produces 2 kilowatts of power. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave, a high-power microwave can cook more food in the same time or the same amount of food in less time. "
Work can be calculated as,(A) force  time (B) force  power (C) power  time (D) power  distance,C,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
A device does 2000 joules of work in 10 seconds. What is the power of the device?,(A) 20 (B) 000 W (C) b 2000 W (D) c 200 W (E) d 20 W,C,"Power can be calculated using the formula above, if the amount of work and time are known. For example, assume that a small engine does 3000 joules of work in 2 seconds. Then the power of the motor is: Power = 3000 J = 1500 J/s, or 1500 W 2s You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 2000-watt hair dryer for 30 seconds, how much work is done? First express 2000 watts in J/s and then substitute this value for power in the work equation: Work = 2000 J/s  30 s = 60, 000 J For a video presentation on calculating power and work, go to this link:  Problem Solving Problem: An electric mixer does 2500 joules of work in 5 seconds. What is its power? Solution: Use the equation: Power = Work Time . Power = 2500 J = 500 J/s, or 500 W 5s You Try It! Problem: How much work can be done in 30 seconds by a 1000-watt microwave? "
One horsepower is the amount of work a horse can do in one,(A) second (B) minute (C) hour (D) day,B,"Sometimes power is measured in a unit called the horsepower. For example, the power of car engines is usually expressed in horsepowers. One horsepower is the amount of work a horse can do in 1 minute. It equals 745 watts of power. Compare the horsepowers in the Figure 1.2 to the other Figure 1.3. This team of three horses provides 3 horsepowers of power. This big tractor provides 180 horsepowers of power. Q: If the team of horses and the tractor do the same amount of work plowing a field, which will get the job done faster? A: The tractor will get the job done faster because it has more power. In fact, because the tractor has 30 times the power of the six-horse team, ideally it can do the same work 30 times faster! "
Machines that increase the distance over which force is applied include,(A) hammers (B) doorknobs (C) nutcrackers (D) pry bars,A,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
Ways that machines make work easier include,(A) increasing force (B) increasing work (C) increasing efficiency (D) all of the above,A,"A machine is any device that makes work easier by changing a force. When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. Recall that work equals force multiplied by distance: Work = Force  Distance The force you apply to a machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. So if a machine increases the force applied, it must apply the force over a shorter distance. Similarly, if a machine increases the distance over which the force is applied, it must apply less force. "
"If you apply 20 N of force to the handle end of a canoe paddle, how much force might the paddle end apply to the water?",(A) 40 N (B) 30 N (C) 20 N (D) 10 N,D,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
"If the output work of a machine is 3000 J and the input work is 4000 J, what is the efficiency of the machine?",(A) 133% (B) 100% (C) 75% (D) 66%,C,"Efficiency can be calculated with the equation: Efficiency = Output work 100% Input work Consider a machine that puts out 6000 joules of work. To produce that much work from the machine requires the user to put in 8000 joules of work. To find the efficiency of the machine, substitute these values into the equation for efficiency: Efficiency = 6000 J 100% = 75% 8000 J You Try It! Problem: Rani puts 10,000 joules of work into a car jack. The car jack, in turn, puts out 7000 joules of work to raise up the car. What is the efficiency of the jack? "
"If the ideal mechanical advantage of a machine equals 1, then the actual mechanical advantage of the machine must be",(A) greater than 1 (B) equal to 1 (C) less than 1 (D) less than zero,C,"How much a machine changes the input force is its mechanical advantage. Mechanical advantage is the ratio of the output force to the input force, so it can be represented by the equation: Actual Mechanical Advantage = Output force Input force Note that this equation represents the actual mechanical advantage of a machine. The actual mechanical advantage takes into account the amount of the input force that is used to overcome friction. The equation yields the factor by which the machine changes the input force when the machine is actually used in the real world. "
The output distance of a machine is always greater than the input distance.,(A) true (B) false,B,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
Using a machine increases the amount of work that is done for a given amount of force.,(A) true (B) false,B,"Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Q: If a machine increases the force applied, what does this tell you about the distance over which the force is applied by the machine: A: The machine must apply the force over a shorter distance. Thats because a machine doesnt change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease. For the same reason, if a machine increases the distance over which the force is applied, it must apply less force. "
A machine increases the applied force by increasing the distance over which the force is applied.,(A) true (B) false,B,"Examples of machines that increase the distance over which force is applied are paddles and hammers. Figure 16.9 explains how these machines work. In each case, the machine increases the distance over which the force is applied, but it reduces the strength of the applied force. "
The output force of a machine is always less than the input force.,(A) true (B) false,B,"You read above that machines do not increase the work done on an object. In other words, you cant get more work out of a machine than you put into it. In fact, machines always do less work on the object than the user does on the machine. Thats because all machines must use some of the work put into them to overcome friction. How much work? It depends on the efficiency of the machine. Efficiency is the percent of input work that becomes output work. It is a measure of how well a machine reduces friction. "
The force you apply to a doorknob is less than the force applied by the doorknob to open the door.,(A) true (B) false,A,"Examples of machines that increase force are doorknobs and nutcrackers. Figure 16.8 explains how these machines work. In each case, the force applied by the user is less than the force applied by the machine, but the machine applies the force over a shorter distance. "
All machines that change the strength of the force also change the distance over which the force is applied.,(A) true (B) false,A,"Examples of machines that increase the distance over which force is applied are paddles and hammers. Figure 16.9 explains how these machines work. In each case, the machine increases the distance over which the force is applied, but it reduces the strength of the applied force. "
A machine changes the way that work is done.,(A) true (B) false,A,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
The actual mechanical advantage of a machine is always greater than its ideal mechanical advantage.,(A) true (B) false,B,"As you read above, some machines increase the force put into the machine, while other machines increase the distance over which the force is applied. Still other machines change only the direction of the force. Which way a machine works affects its mechanical advantage. For machines that increase force including ramps, doorknobs, and nutcrackers the output force is greater than the input force. Therefore, the mechanical advantage is greater than 1. For machines that increase the distance over which force is applied, such as paddles and hammers, the output force is less than the input force. Therefore, the mechanical advantage is less than 1. For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. "
All machines change the direction in which force is applied.,(A) true (B) false,B,"Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which it is applied. Two examples of machines that work in this way are claw hammers and the rope systems (pulleys) that raise or lower flags on flagpoles. Figure 16.10 explains how these machines work. In each case, the direction of the force applied by the user is reversed by the machine. How does this make it easier to do the job? "
A machine that applies force over a longer distance also increases the strength of the force.,(A) true (B) false,B,"Examples of machines that increase the distance over which force is applied are paddles and hammers. Figure 16.9 explains how these machines work. In each case, the machine increases the distance over which the force is applied, but it reduces the strength of the applied force. "
"If a machines output distance is greater than the input distance, the ideal mechanical advantage is less than",(A) true (B) false,A,"It can be difficult to measure the input and output forces needed to calculate actual mechanical advantage. Its usually much easier to measure the input and output distances. These measurements can then be used to calculate the ideal mechanical advantage. The ideal mechanical advantage represents the multiplication of input force that would be achieved in the absence of friction. Therefore, it is greater than the actual mechanical advantage because all machines use up some work in overcoming friction. Ideal mechanical advantage is calculated with the equation: Ideal Mechanical Advantage = Input distance Output distance Compare this equation with the equation above for actual mechanical advantage. Notice how the input and output values are switched. This makes sense when you recall that when a machine increases force, it decreases distance and vice versa. You can watch a video about actual and ideal mechanical advantage at this link: http://video.goo Consider the simple ramp in Figure 16.12. A ramp can be used to raise an object up off the ground. The input distance is the length of the sloped surface of the ramp. The output distance is the height of the ramp, or the vertical distance the object is raised. Therefore, the ideal mechanical advantage of the ramp is: Ideal Mechanical Advantage = 6m =3 2m An ideal mechanical advantage of 3 means that the ramp ideally (in the absence of friction) multiplies the output force by a factor of 3. "
"A pry bar changes the strength, distance, and direction of the input force.",(A) true (B) false,A,"Other levers change force or distance in different ways than a hammer removing a nail. How a lever changes force or distance depends on the location of the input and output forces relative to the fulcrum. The input force is the force applied by the user to the lever. The output force is the force applied by the lever to the object. Based on the location of input and output forces, there are three basic types of levers, called first-class, second-class, and third-class levers. The Table 1.1 describes the three classes. Class of Lever Example of Lever in This Class First class Location of Input & Output Forces & Fulcrum* Ideal Mechanical Advantage Change in Direction of Force? Seesaw 1 <1 >1 yes yes yes Second class Wheelbarrow >1 no Third class Hockey stick <1 no = fulcrum I = input force O = output force The Table 1.1 includes the ideal mechanical advantage of each class of lever. The mechanical advantage is the factor by which a machine changes the input force. The ideal mechanical advantage is the increase or decrease in force that would occur if there were no friction to overcome in the use of the machine. Because all machines must overcome some friction, the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. Q: Which class of lever is a hammer when it is used to pry a nail out of a board? What is its mechanical advantage? A: To pry a nail out of a board, the fulcrum is located between the input and output forces. Therefore, when a hammer is used in this way it is a first class lever. The fulcrum is closer to the output force than the input force, so the mechanical advantage is >1. In other words, the hammer increases the force applied to it, making it easier to pry the nail out of the board. "
"If a machine changes only the direction of force, its mechanical advantage is equal to 1.",(A) true (B) false,A,"As you read above, some machines increase the force put into the machine, while other machines increase the distance over which the force is applied. Still other machines change only the direction of the force. Which way a machine works affects its mechanical advantage. For machines that increase force including ramps, doorknobs, and nutcrackers the output force is greater than the input force. Therefore, the mechanical advantage is greater than 1. For machines that increase the distance over which force is applied, such as paddles and hammers, the output force is less than the input force. Therefore, the mechanical advantage is less than 1. For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. "
A lever is a machine that changes the direction of the force that is applied to it.,(A) true (B) false,B,"A lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied. How does a hammer make it easier to pull a nail out of a board? First, it changes the direction of the force applied to the hammerthe hand pushes down on the handle while the claw end of the hammer head pulls up. Often, you can push down with more force than you can push up because you can put your own weight behind it. The hammer also increases the strength of the force that is applied to it. It easily pulls the nail out of the board, which you couldnt do with your hands alone. On the other hand, the hammer decreases the distance over which the force is applied. The hand pushing down on the handle moves the handle over a distance of several inches, whereas the hammer pulls up on the nail only an inch or two. Q: Where is the fulcrum of the hammer when it is used to pull a nail out of a board? In other words, around what point does the hammer rotate? A: The fulcrum is the point where the head of the hammer rests on the surface of the board. "
number of times a machine multiplies the input force,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,D,Another measure of the effectiveness of a machine is its mechanical advantage. Mechanical advantage is the number of times a machine multiplies the input force. It can be calculated with the equation: Mechanical Advantage = Output force Input force This equation computes the actual mechanical advantage of a machine. It takes into account the reduction in output force that is due to friction. It shows how much a machine actually multiplies force when it used in the real world. 
distance over which force is applied to a machine,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,E,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
percent of input work that becomes output work,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,A,"Efficiency can be calculated with the equation: Efficiency = Output work 100% Input work Consider a machine that puts out 6000 joules of work. To produce that much work from the machine requires the user to put in 8000 joules of work. To find the efficiency of the machine, substitute these values into the equation for efficiency: Efficiency = 6000 J 100% = 75% 8000 J You Try It! Problem: Rani puts 10,000 joules of work into a car jack. The car jack, in turn, puts out 7000 joules of work to raise up the car. What is the efficiency of the jack? "
force applied to a machine,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,B,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
any device that makes work easier by changing a force,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,G,"Examples of machines that increase force are doorknobs and nutcrackers. Figure 16.8 explains how these machines work. In each case, the force applied by the user is less than the force applied by the machine, but the machine applies the force over a shorter distance. "
distance over which a machine applies force,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,F,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
force applied by a machine,(A) efficiency (B) input force (C) output force (D) mechanical advantage (E) input distance (F) output distance (G) machine,C,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
A machine can make work easier by,(A) increasing the amount of force that is applied (B) increasing the distance over which force is applied (C) changing the direction in which force is applied (D) any of the above,D,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
Examples of machines that increase force include,(A) doorknobs (B) hammers (C) canoe paddles (D) two of the above,A,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
How does a nutcracker change the force applied to it?,(A) It increases the force that is applied (B) It increases the distance over which force is applied (C) It changes the direction in which force is applied (D) two of the above,A,"Examples of machines that increase force are doorknobs and nutcrackers. Figure 16.8 explains how these machines work. In each case, the force applied by the user is less than the force applied by the machine, but the machine applies the force over a shorter distance. "
A machine that increases the applied force and also changes its direction is a,(A) hammer (B) canoe paddle (C) pry bar (D) doorknob,C,"Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which it is applied. Two examples of machines that work in this way are claw hammers and the rope systems (pulleys) that raise or lower flags on flagpoles. Figure 16.10 explains how these machines work. In each case, the direction of the force applied by the user is reversed by the machine. How does this make it easier to do the job? "
Which of the following could be the efficiency of a machine?,(A) 200% (B) 150% (C) 100% (D) 75%,D,"Efficiency can be calculated with the equation: Efficiency = Output work 100% Input work Consider a machine that puts out 6000 joules of work. To produce that much work from the machine requires the user to put in 8000 joules of work. To find the efficiency of the machine, substitute these values into the equation for efficiency: Efficiency = 6000 J 100% = 75% 8000 J You Try It! Problem: Rani puts 10,000 joules of work into a car jack. The car jack, in turn, puts out 7000 joules of work to raise up the car. What is the efficiency of the jack? "
What is the mechanical advantage of a machine that increases the distance over which force is applied?,(A) less than 1 (B) equal to 1 (C) greater than 1 (D) greater than 2,A,"As you read above, some machines increase the force put into the machine, while other machines increase the distance over which the force is applied. Still other machines change only the direction of the force. Which way a machine works affects its mechanical advantage. For machines that increase force including ramps, doorknobs, and nutcrackers the output force is greater than the input force. Therefore, the mechanical advantage is greater than 1. For machines that increase the distance over which force is applied, such as paddles and hammers, the output force is less than the input force. Therefore, the mechanical advantage is less than 1. For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. "
"If the output force of a machine is greater than input force, the mechanical advantage of the machine is",(A) greater than 1 (B) equal to 1 (C) less than 1 (D) any of the above,A,"As you read above, some machines increase the force put into the machine, while other machines increase the distance over which the force is applied. Still other machines change only the direction of the force. Which way a machine works affects its mechanical advantage. For machines that increase force including ramps, doorknobs, and nutcrackers the output force is greater than the input force. Therefore, the mechanical advantage is greater than 1. For machines that increase the distance over which force is applied, such as paddles and hammers, the output force is less than the input force. Therefore, the mechanical advantage is less than 1. For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. "
Which type of simple machine is a chisel?,(A) lever (B) screw (C) wedge (D) none of the above,C,"There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple machines. These machines are called compound machines. An example of a compound machine is a wheelbarrow (see bottom of Figure 1.4). It consists of two simple machines: a lever and a wheel and axle. Many compound machines are much more complex and consist of many simple machines. Examples include washing machines and cars. "
Which type of simple machine is the head of an axe?,(A) wedge (B) lever (C) screw (D) none of the above,A,"There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple machines. These machines are called compound machines. An example of a compound machine is a wheelbarrow (see bottom of Figure 1.4). It consists of two simple machines: a lever and a wheel and axle. Many compound machines are much more complex and consist of many simple machines. Examples include washing machines and cars. "
Which of the following is an example of a screw?,(A) spiral staircase (B) Ferris wheel (C) seesaw (D) axe,A,"A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move objects to a greater depth (or higher elevation) by increasing the force applied to the screw. Many screws are used to hold things together, such as two pieces of wood or a screw cap and bottle. When you use a screw, you apply force to turn the inclined plane. The screw, in turn, applies greater force to the object, such as the wood or bottle top. Q: Can you identify the inclined plane in each example of a screw pictured in the Figure 1.1? A: The inclined plane of the screw on the left consists of the ridges, or threads, that wrap around the central cylinder of the screw. The inclined plane of the cap on the right consists of the ridges that wrap around the inner sides of the cap. "
Which of the following is a second-class lever?,(A) seesaw (B) chisel (C) wheelbarrow (D) hockey stick,C,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
The ideal mechanical advantage of a screw is always,(A) less than 1 (B) equal to 1 (C) greater than 1 (D) greater than 2,C,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advantage of a screw is always greater than 1. Look at the two screws in the Figure 1.2. In the screw on the right, the threads of the inclined plane are closer together. This screw has a greater mechanical advantage and is easier to turn than the screw on the left, so it takes less force to penetrate the wood with the right screw. The trade-off is that more turns of the screw are needed to do the job because the distance over which the input force must be applied is greater. Q: Why is it harder to turn a screw with more widely spaced threads? A: The screw moves farther with each turn when the threads are more widely space, so more force must be applied to turn the screw and cover the greater distance. "
The ideal mechanical advantage of a pulley equals the,(A) number of rope segments lifting up on the object (B) length of the rope segments between the pulley and the object (C) height of the pulley above the surface of the ground (D) number of rope segments between the pulley and the beam,A,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
Which statement about a wheel and axle is true?,(A) It consists of two simple machines (B) It changes the direction of the applied force (C) It changes the distance over which the force is applied (D) two of the above,C,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
Which class of lever does not change the direction of the applied force?,(A) class 1 (B) class 2 (C) class 3 (D) two of the above,D,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
Which of the following is an example of a third class lever?,(A) seesaw (B) wheelbarrow (C) hockey stick (D) pry bar,C,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
The ideal mechanical advantage of an inclined plane is always,(A) less than one (B) equal to one (C) greater than one (D) less than zero,C,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of output force (the force put out by the machined) to input force (the force put into the machine). For an inclined plane, less force is put into moving an object up the slope than if the object were lifted straight up, so the mechanical advantage is greater than 1. The more gradual the slope of the inclined plane, the less input force is needed and the greater the mechanical advantage. Q: Which inclined plane pictured in the Figure 1.2 has a greater mechanical advantage? A: The inclined plane on the right has a more gradual slope, so it has a greater mechanical advantage. Less force is needed to move objects up the gentler slope, yet the objects attain the same elevation as they would if more force were used to push them up the steeper slope. "
A wheel and axle increase the applied force when,(A) the input distance is equal to the output distance (B) the input distance is less than the output distance (C) the input force is applied to the wheel (D) the output force is applied by the wheel,C,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
How many rope segments pull up on the object in a single moveable pulley?,(A) 1 (B) 2 (C) 3 (D) 4,B,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
There are seven different types of simple machines.,(A) true (B) false,B,"There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple machines. These machines are called compound machines. An example of a compound machine is a wheelbarrow (see bottom of Figure 1.4). It consists of two simple machines: a lever and a wheel and axle. Many compound machines are much more complex and consist of many simple machines. Examples include washing machines and cars. "
The input distance of an inclined plane is always greater than the output distance.,(A) true (B) false,A,"The man in Figure 16.14 is using a ramp to move a heavy dryer up to the back of a truck. The highway in the figure switches back and forth so it climbs up the steep hillside. Both the ramp and the highway are examples of inclined planes. An inclined plane is a simple machine consisting of a sloping surface that connects lower and higher elevations. The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation. On the other hand, the output force is greater than the input force because it is applied over a shorter distance. Like other simple machines, the ideal mechanical advantage of an inclined plane is given by: Ideal Mechanical Advantage = Input distance Output distance For an inclined plane, the input distance is the length of the sloping surface, and the output distance is the maximum height of the inclined plane. This was illustrated in Figure 16.12. Because the sloping surface is always greater than the height of the inclined plane, the ideal mechanical advantage of an inclined plane is always greater than 1. An inclined plane with a longer sloping surface relative to its height has a gentler slope. An inclined plane with a gentler slope has a greater mechanical advantage and requires less input force to move an object to a higher elevation. "
The input force is always applied to the thinner side of a wedge.,(A) true (B) false,B,"Imagine trying to slice a tomato with a fork or spoon instead of a knife, like the one in Figure 16.15. The knife makes the job a lot easier because of the wedge shape of the blade. A wedge is a simple machine that consists of two inclined planes. But unlike one inclined plane, a wedge works only when it moves. It has a thin end and thick end, and the thin end is forced into an object to cut or split it. The chisel in Figure 16.15 is another example of a wedge. The input force is applied to the thick end of a wedge, and it acts over the length of the wedge. The output force pushes against the object on both sides of the wedge, so the output distance is the thickness of the wedge. Therefore, the ideal mechanical advantage of a wedge can be calculated as: Ideal Mechanical Advantage = Length of wedge Maximum thickness of wedge The length of a wedge is always greater than its maximum thickness. As a result, the ideal mechanical advantage of a wedge is always greater than 1. "
The center of a wheel and axle is called the fulcrum.,(A) true (B) false,B,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
"The closer together the threads of a screw are, the harder it is to turn the screw.",(A) true (B) false,B,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advantage of a screw is always greater than 1. Look at the two screws in the Figure 1.2. In the screw on the right, the threads of the inclined plane are closer together. This screw has a greater mechanical advantage and is easier to turn than the screw on the left, so it takes less force to penetrate the wood with the right screw. The trade-off is that more turns of the screw are needed to do the job because the distance over which the input force must be applied is greater. Q: Why is it harder to turn a screw with more widely spaced threads? A: The screw moves farther with each turn when the threads are more widely space, so more force must be applied to turn the screw and cover the greater distance. "
A wedge is used to cut or split objects.,(A) true (B) false,A,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
"When you use a hammer to pry a nail out of board, the hammer is a first class lever.",(A) true (B) false,A,"Did you ever use a hammer to pull a nail out of a board? If not, you can see how its done in Figure 16.18. When you pull down on the handle of the hammer, the claw end pulls up on the nail. A hammer is an example of a lever. A lever is a simple machine consisting of a bar that rotates around a fixed point called the fulcrum. For a video introduction to levers using skateboards as examples, go to this link:  MEDIA Click image to the left or use the URL below. URL:  A lever may or may not increase the force applied, and it may or may not change the direction of the force. It all depends on the location of the input and output forces relative to the fulcrum. In this regard, there are three basic types of levers, called first-class, second-class, and third-class levers. Figure 16.19 describes the three classes. "
A lever always increases the force applied to the lever.,(A) true (B) false,B,"All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change. This occurs with both second- and third-class levers. When the input force is applied farther from the fulcrum, the input distance is greater than the output distance, so the ideal mechanical advantage is greater than 1. This always occurs with second-class levers and may occur with first-class levers. When the input force is applied closer to the fulcrum, the input distance is less than the output distance, so the ideal mechanical advantage is less than 1. This always occurs with third-class levers and may occur with first-class levers. When both forces are the same distance from the fulcrum, the input distance equals the output distance, so the ideal mechanical advantage equals 1. This occurs only with first class-levers. "
"When you turn a screw, you apply force along its inclined plane.",(A) true (B) false,A,"A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move objects to a greater depth (or higher elevation) by increasing the force applied to the screw. Many screws are used to hold things together, such as two pieces of wood or a screw cap and bottle. When you use a screw, you apply force to turn the inclined plane. The screw, in turn, applies greater force to the object, such as the wood or bottle top. Q: Can you identify the inclined plane in each example of a screw pictured in the Figure 1.1? A: The inclined plane of the screw on the left consists of the ridges, or threads, that wrap around the central cylinder of the screw. The inclined plane of the cap on the right consists of the ridges that wrap around the inner sides of the cap. "
The wheel of a Ferris wheel turns more quickly than the axle.,(A) true (B) false,A,"Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. The smaller, inner ring or cylinder is called the axle. The bigger, outer ring or cylinder is called the wheel. The car steering wheel in Figure 16.20 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. In both cases, the direction of the force does not change, but the force is either increased or applied over a greater distance. When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force, so the ideal mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The speed of the wheel is one reason that the Ferris wheel ride is so exciting. When the input force is applied to the wheel, as it is with a steering wheel, the axle turns over a shorter distance but with greater force, so the ideal mechanical advantage is greater than 1. This allows you to turn the steering wheel with relatively little effort, while the axle of the steering wheel applies enough force to turn the car. "
A lever may or may not change the strength of the applied force.,(A) true (B) false,A,"All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with first-class levers. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change. This occurs with both second-class and third-class levers. When the input force is applied farther from the fulcrum than the output force is, the output force is greater than the input force, and the ideal mechanical advantage is greater than 1. This always occurs with second-class levers and may occur with first-class levers. When the input force is applied closer to the fulcrum than the output force is, the output force is less than the input force, and the ideal mechanical advantage is less than 1. This always occurs with third-class levers and may occur with first-class levers. When the input and output forces are the same distance from the fulcrum, the output force equals the input force, and the ideal mechanical advantage is 1. This occurs only with first some first-class levers. "
The wheel of a wheel and axle turns more slowly than the axle.,(A) true (B) false,B,"Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. The smaller, inner ring or cylinder is called the axle. The bigger, outer ring or cylinder is called the wheel. The car steering wheel in Figure 16.20 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. In both cases, the direction of the force does not change, but the force is either increased or applied over a greater distance. When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force, so the ideal mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The speed of the wheel is one reason that the Ferris wheel ride is so exciting. When the input force is applied to the wheel, as it is with a steering wheel, the axle turns over a shorter distance but with greater force, so the ideal mechanical advantage is greater than 1. This allows you to turn the steering wheel with relatively little effort, while the axle of the steering wheel applies enough force to turn the car. "
A single fixed pulley has an ideal mechanical advantage of 1.,(A) true (B) false,A,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
A compound pulley always contains at least two fixed pulleys.,(A) true (B) false,B,"Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulley. The three types of pulleys are compared in the Table 1.1. Q: Which type of pulley is the old pulley in the opening image? A: The old pulley is a single fixed pulley. It is securely attached to the beam above it. Type of Pulley How It Works Example Single fixed pul- ley Flagpole pulley No. of Rope Segments Pulling Up 1 Ideal Mechani- cal Advantage 1 Change Direction Force? yes Single moveable pulley Zip-line pulley 2 2 no Compound pulley (fixed & moveable pulleys) Crane pulley 2 2 varies in of "
A zip-line pulley is an example of a single moveable pulley.,(A) true (B) false,A,"Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulley. The three types of pulleys are compared in the Table 1.1. Q: Which type of pulley is the old pulley in the opening image? A: The old pulley is a single fixed pulley. It is securely attached to the beam above it. Type of Pulley How It Works Example Single fixed pul- ley Flagpole pulley No. of Rope Segments Pulling Up 1 Ideal Mechani- cal Advantage 1 Change Direction Force? yes Single moveable pulley Zip-line pulley 2 2 no Compound pulley (fixed & moveable pulleys) Crane pulley 2 2 varies in of "
simple machine that consists of a rope and grooved wheel,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,C,"A pulley is a simple machine that consists of a rope and grooved wheel. The rope fits into the groove in the wheel, and pulling on the rope turns the wheel. Pulleys are generally used to lift objects, especially heavy objects. The object lifted by a pulley is called the load. The force applied to the pulley is called the effort. Q: Can you guess what the pulley pictured above is used for? A: The pulley is used to lift heavy buckets full of water out of the well. "
type of lever in which the fulcrum is between the input and output forces,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,E,"All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change. This occurs with both second- and third-class levers. When the input force is applied farther from the fulcrum, the input distance is greater than the output distance, so the ideal mechanical advantage is greater than 1. This always occurs with second-class levers and may occur with first-class levers. When the input force is applied closer to the fulcrum, the input distance is less than the output distance, so the ideal mechanical advantage is less than 1. This always occurs with third-class levers and may occur with first-class levers. When both forces are the same distance from the fulcrum, the input distance equals the output distance, so the ideal mechanical advantage equals 1. This occurs only with first class-levers. "
simple machine consisting of two connected rings or cylinders that both turn around a single center point,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,F,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
simple machine that consists of an inclined plane wrapped around a cylinder or cone,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,D,"An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined plane. A ramp like the one in the Figure 1.1 is another example of an inclined plane. Inclined planes make it easier to move objects to a higher elevation. The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation. "
fixed point of a lever around which the bar rotates,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,G,"A lever is a simple machine consisting of a bar that rotates around a fixed point. The fixed point of a lever is called the fulcrum. Like other machines, a lever makes work easier by changing the force applied to the machine or the distance over which the force is applied. How does a hammer make it easier to pull a nail out of a board? First, it changes the direction of the force applied to the hammerthe hand pushes down on the handle while the claw end of the hammer head pulls up. Often, you can push down with more force than you can push up because you can put your own weight behind it. The hammer also increases the strength of the force that is applied to it. It easily pulls the nail out of the board, which you couldnt do with your hands alone. On the other hand, the hammer decreases the distance over which the force is applied. The hand pushing down on the handle moves the handle over a distance of several inches, whereas the hammer pulls up on the nail only an inch or two. Q: Where is the fulcrum of the hammer when it is used to pull a nail out of a board? In other words, around what point does the hammer rotate? A: The fulcrum is the point where the head of the hammer rests on the surface of the board. "
simple machine consisting of a sloping surface that connects lower and higher elevations,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,A,"An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined plane. A ramp like the one in the Figure 1.1 is another example of an inclined plane. Inclined planes make it easier to move objects to a higher elevation. The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation. "
type of lever in which input and output forces are on the same side of the fulcrum,(A) inclined plane (B) class 2 lever (C) pulley (D) screw (E) class 1 lever (F) wheel and axle (G) fulcrum,B,"All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change. This occurs with both second- and third-class levers. When the input force is applied farther from the fulcrum, the input distance is greater than the output distance, so the ideal mechanical advantage is greater than 1. This always occurs with second-class levers and may occur with first-class levers. When the input force is applied closer to the fulcrum, the input distance is less than the output distance, so the ideal mechanical advantage is less than 1. This always occurs with third-class levers and may occur with first-class levers. When both forces are the same distance from the fulcrum, the input distance equals the output distance, so the ideal mechanical advantage equals 1. This occurs only with first class-levers. "
how greatly a machine increases the applied force,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,B,"Many machinesincluding inclined planes such as rampsincrease the strength of the force put into the machine but decrease the distance over which the force is applied. Other machines increase the distance over which the force is applied but decrease the strength of the force. Still other machines change the direction of the force, with or without also increasing its strength or distance. Which way a machine works determines its mechanical advantage, as shown in the Table 1.1. Strength of Force increases decreases stays the same (changes direction only) Distance Over Force is Applied decreases increases stays the same which Mechanical Advantage Example >1 <1 =1 ramp hammer flagpole pulley "
Simple machines in a pair of scissors include,(A) two levers (B) two wedges (C) one wheel and axle (D) two of the above,D,"Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum lies between the input and output points, so the levers are first-class levers. They change the direction of force. They may or may not also increase force, depending on the relative lengths of the handles and blades. The blades themselves are wedges, with a sharp cutting edge and a thicker dull edge. "
how well a machine deals with friction,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,F,"Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of many simple machines, friction can become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts of a machine so they slide over each other more easily. This is how friction is reduced in a car engine. "
Compound machines include all of the following except a(n),(A) chisel (B) bicycle (C) automobile (D) wheelbarrow,A,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars may consist of hundreds or even thousands of simple machines. "
An axe is a compound machine that consists of a wedge and a(n),(A) screw (B) inclined plane (C) first class lever (D) third class lever,D,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
example of a third class lever,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,C,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
any machine that consists of more than one simple machine,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,A,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars may consist of hundreds or even thousands of simple machines. "
A compound machine tends to be less efficient than a simple machine because a compound machine,(A) produces more work (B) exerts a greater force (C) has more moving parts (D) none of the above,C,"Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts so they slide over each other more easily. This is how a cars friction is reduced. Compound machines have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater is its mechanical advantage. "
example of a wheel and axle that works as a pulley,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,E,"Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. The smaller, inner ring or cylinder is called the axle. The bigger, outer ring or cylinder is called the wheel. The car steering wheel in Figure 16.20 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. In both cases, the direction of the force does not change, but the force is either increased or applied over a greater distance. When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force, so the ideal mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The speed of the wheel is one reason that the Ferris wheel ride is so exciting. When the input force is applied to the wheel, as it is with a steering wheel, the axle turns over a shorter distance but with greater force, so the ideal mechanical advantage is greater than 1. This allows you to turn the steering wheel with relatively little effort, while the axle of the steering wheel applies enough force to turn the car. "
Which of the following machines has the greatest mechanical advantage?,(A) mountain bike (B) inline skate (C) roller skate (D) tricycle,A,"The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater its mechanical advantage tends to be. Q: Assume that the lever and the wheel and axle of a wheelbarrow each have a mechanical advantage of 2. What is the mechanical advantage of the wheelbarrow? A: The mechanical advantage of the wheelbarrow is the product of the mechanical advantage of the lever (2) and the mechanical advantage of the wheel and axle (2). Therefore, the wheelbarrow has a mechanical advantage of 4. "
machine consisting of a wheel and axle and a lever,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,D,"Look at the wheelbarrow in the Figure 1.1. It is used to carry heavy objects. It consists of two simple machines: a lever and a wheel and axle. Effort is applied to the lever by picking up the handles of the wheelbarrow. The lever, in turn, applies upward force to the load. The force is increased by the lever, making the load easier to lift. Effort is applied to the wheel of the wheelbarrow by pushing it over the ground. The rolling wheel turns the axle and increases the force, making it easier to push the load. "
machine consisting of two levers and two wedges,(A) compound machine (B) mechanical advantage (C) fishing rod (D) wheelbarrow (E) fishing reel (F) efficiency (G) scissors,G,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
A wheel and axle is an example of a compound machine.,(A) true (B) false,B,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. For example, a wheelbarrow consists of a lever, as you read earlier in the lesson ""Simple Machines,"" and also a wheel and axle. Other compound machines, such as cars, consist of hundreds or even thousands of simple machines. Two common examples of compound machines are scissors and fishing rods with reels. To view a young students compound machine invention that includes several simple machines, watch the video at this link:  . To see if you can identify the simple machines in a lawn mower, go to the URL below and click on Find the Simple Machines. "
A pulley system that contains a fixed and a moveable pulley is a compound machine.,(A) true (B) false,A,"Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulley. The three types of pulleys are compared in the Table 1.1. Q: Which type of pulley is the old pulley in the opening image? A: The old pulley is a single fixed pulley. It is securely attached to the beam above it. Type of Pulley How It Works Example Single fixed pul- ley Flagpole pulley No. of Rope Segments Pulling Up 1 Ideal Mechani- cal Advantage 1 Change Direction Force? yes Single moveable pulley Zip-line pulley 2 2 no Compound pulley (fixed & moveable pulleys) Crane pulley 2 2 varies in of "
A single pulley is less efficient than a pulley system that consists of two or more pulleys.,(A) true (B) false,B,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
The mechanical advantage of a compound machine is generally less than that of a simple machine.,(A) true (B) false,B,"Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts so they slide over each other more easily. This is how a cars friction is reduced. Compound machines have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater is its mechanical advantage. "
Friction tends to be a bigger problem in a compound machine than in a simple machine.,(A) true (B) false,A,"Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts so they slide over each other more easily. This is how a cars friction is reduced. Compound machines have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater is its mechanical advantage. "
Simple machines in a bicycle include,(A) wheels and axles (B) pulleys (C) levers (D) all of the above,D,"There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple machines. These machines are called compound machines. An example of a compound machine is a wheelbarrow (see bottom of Figure 1.4). It consists of two simple machines: a lever and a wheel and axle. Many compound machines are much more complex and consist of many simple machines. Examples include washing machines and cars. "
Which of the following is a compound machine?,(A) wheel and axle (B) scissors (C) pulley (D) lever,B,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. For example, a wheelbarrow consists of a lever, as you read earlier in the lesson ""Simple Machines,"" and also a wheel and axle. Other compound machines, such as cars, consist of hundreds or even thousands of simple machines. Two common examples of compound machines are scissors and fishing rods with reels. To view a young students compound machine invention that includes several simple machines, watch the video at this link:  . To see if you can identify the simple machines in a lawn mower, go to the URL below and click on Find the Simple Machines. "
Which of the following machines contains one or more levers?,(A) wheelbarrow (B) scissors (C) fishing rod (D) all of the above,D,"There are six types of simple machines that are the basis of all other machines. They are the inclined plane, lever, wedge, screw, pulley, and wheel and axle. The six types are pictured in the Figure 1.4. Youve probably used some of these simple machines yourself. Most machines are combinations of two or more simple machines. These machines are called compound machines. An example of a compound machine is a wheelbarrow (see bottom of Figure 1.4). It consists of two simple machines: a lever and a wheel and axle. Many compound machines are much more complex and consist of many simple machines. Examples include washing machines and cars. "
The fulcrum in a pair of scissors is always located,(A) between the input and output points (B) closer to the input point (C) closer to the output point (D) two of the above,A,"Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum lies between the input and output points, so the levers are first-class levers. They change the direction of force. They may or may not also increase force, depending on the relative lengths of the handles and blades. The blades themselves are wedges, with a sharp cutting edge and a thicker dull edge. "
The mechanical advantage of a compound machine equals the,(A) sum of the mechanical advantages of all its simple machines (B) product of the mechanical advantages of all its simple machines (C) highest mechanical advantage of all its simple machines (D) average mechanical advantage of all of its simple machines,B,"The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater its mechanical advantage tends to be. Q: Assume that the lever and the wheel and axle of a wheelbarrow each have a mechanical advantage of 2. What is the mechanical advantage of the wheelbarrow? A: The mechanical advantage of the wheelbarrow is the product of the mechanical advantage of the lever (2) and the mechanical advantage of the wheel and axle (2). Therefore, the wheelbarrow has a mechanical advantage of 4. "
The way friction is reduced in a compound machine such as a car is with,(A) fans (B) heaters (C) lubricants (D) none of the above,C,"Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of many simple machines, friction can become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts of a machine so they slide over each other more easily. This is how friction is reduced in a car engine. "
Some compound machines consist of thousands of simple machines.,(A) true (B) false,A,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars may consist of hundreds or even thousands of simple machines. "
The output force is exerted by the handle ends of the levers in scissors.,(A) true (B) false,B,"Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum lies between the input and output points, so the levers are first-class levers. They change the direction of force. They may or may not also increase force, depending on the relative lengths of the handles and blades. The blades themselves are wedges, with a sharp cutting edge and a thicker dull edge. "
Scissors change the direction of the input force.,(A) true (B) false,A,"Look at the scissors in Figure 16.24. As you can see from the figure, scissors consist of two levers and two wedges. You apply force to the handle ends of the levers, and the output force is exerted by the blade ends of the levers. The fulcrum of both levers is where they are joined together. Notice that the fulcrum lies between the input and output points, so the levers are first-class levers. They change the direction of force. They may or may not also increase force, depending on the relative lengths of the handles and blades. The blades themselves are wedges, with a sharp cutting edge and a thicker dull edge. "
The fulcrum in a fishing rod is at the center of the rod.,(A) true (B) false,B,"The fishing rod with reel shown in Figure 16.25 is another compound machine. The rod is a third-class lever, with the fulcrum on one end of the rod, the input force close to the fulcrum, and the output force at the other end of the rod. The output distance is greater than the input distance, so the angler can fling the fishing line far out into the water with just a flick of the wrist. The reel is a wheel and axle that works as a pulley. The fishing line is wrapped around the wheel. Using the handle to turn the axle of the wheel winds or unwinds the line. "
Compound machines have more moving parts than simple machines.,(A) true (B) false,A,"Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts so they slide over each other more easily. This is how a cars friction is reduced. Compound machines have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater is its mechanical advantage. "
"The fewer simple machines a compound machine contains, the greater its mechanical advantage.",(A) true (B) false,B,"The mechanical advantage of a machine is the factor by which it changes the force applied to the machine. Many machines increase the force applied to them, and this is how they make work easier. Compound machines tend to have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater its mechanical advantage tends to be. Q: Assume that the lever and the wheel and axle of a wheelbarrow each have a mechanical advantage of 2. What is the mechanical advantage of the wheelbarrow? A: The mechanical advantage of the wheelbarrow is the product of the mechanical advantage of the lever (2) and the mechanical advantage of the wheel and axle (2). Therefore, the wheelbarrow has a mechanical advantage of 4. "
Compound machines have more friction to overcome than do simple machines.,(A) true (B) false,A,"Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of a large number of simple machines, friction may become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts so they slide over each other more easily. This is how a cars friction is reduced. Compound machines have a greater mechanical advantage than simple machines. Thats because the mechanical advantage of a compound machine equals the product of the mechanical advantages of all its component simple machines. The greater the number of simple machines it contains, the greater is its mechanical advantage. "
energy stored in an object because of its position or shape,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,G,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
A leaf hanging motionless on a tree has,(A) no energy (B) elastic energy (C) kinetic energy (D) potential energy,D,"Did you ever see a scene like the one in Figure 17.4? In many parts of the world, trees lose their leaves in autumn. The leaves turn color and then fall from the trees to the ground. As the leaves are falling, they have kinetic energy. While they are still attached to the trees they also have energy, but its not because of motion. Instead, they have stored energy, called potential energy. An object has potential energy because of its position or shape. For example leaves on trees have potential energy because they could fall due to the pull of gravity. "
stored energy due to an objects shape,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,F,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
"When a moving bat hits a ball, what happens to the kinetic energy of the bat?",(A) All of it becomes potential energy (B) Most of it is transferred to the ball (C) All of it is used up and gone (D) Most of it changes to heat,B,"What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo is doing the work of pounding the nail into the board. You can see a cartoon introduction to kinetic energy and its relation to work at this URL:  . The amount of kinetic energy in a moving object depends on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. The kinetic energy of a moving object can be calculated with the equation: 1 Kinetic Energy (KE) = mass  velocity2 2 This equation for kinetic energy shows that velocity affects kinetic energy more than mass does. For example, if mass doubles, kinetic energy also doubles. But if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. You can see for yourself how mass and velocity affect kinetic energy by working through the problems below. Problem Solving Problem: Juan has a mass of 50 kg. If he is running at a velocity of 2 m/s, how much kinetic energy does he have? Solution: Use the formula: KE = 12 mass  velocity2 1 50 kg  (2 m/s2 ) 2 = 100 kg  m2 /s2 = 100 N  m, or 100 J KE = You Try It! Problem: What is Juans kinetic energy if he runs at a velocity of 4 m/s? Problem: Juans dad has a mass of 100 kg. How much kinetic energy does he have if he runs at a velocity of 2 m/s? "
use of force to move matter,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,D,"Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. "
A 40-kilogram boy is running at a velocity of 3 m/s. What is his kinetic energy?,(A) 180 J (B) 120 J (C) 43 J (D) 13 J,A,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
"Lana, who weighs 400 newtons, is about to dive from a 10-meter diving board. Her gravitational potential energy is",(A) 40 J (B) 2000 J (C) 4000 J (D) 40 (E) 000 J,C,"Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in the Figure 1.1. Gravitational potential energy depends on an objects weight and its height above the ground. It can be calculated with the equation: Gravitational potential energy (GPE) = weight  height Consider the little girl on the sled, pictured in the Figure 1.1. She weighs 140 Newtons, and the top of the hill is 4 meters higher than the bottom of the hill. As she sits at the top of the hill, the childs gravitational potential energy is: GPE = 140 N  4 m = 560 N  m Notice that the answer is given in Newton  meters (N  m), which is the SI unit for energy. A Newton  meter is the energy needed to move a weight of 1 Newton over a distance of 1 meter. A Newton  meter is also called a joule (J). Q: The gymnast on the balance beam pictured in the Figure 1.1 weighs 360 Newtons. If the balance beam is 1.2 meters above the ground, what is the gymnasts gravitational potential energy? A: Her gravitational potential energy is: GPE = 360 N  1.2 m = 432 N  m, or 432 J "
energy of moving matter,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,B,"Energy is the ability to cause changes in matter. For example, your body uses chemical energy when you lift your arm or take a step. In both cases, energy is used to move matteryou. Any matter that is moving has energy just because its moving. The energy of moving matter is called kinetic energy. Scientists think that the particles of all matter are in constant motion. In other words, the particles of matter have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. "
stored energy due to an objects position,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,E,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
Energy is converted from kinetic energy to potential energy when you,(A) ski down a hill (B) climb a mountain (C) run around a level track (D) two of the above,B,"Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter  you. The energy of moving matter is called kinetic energy. "
ability to do work,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,A,What explains all of these events? The answer can be summed up in one word: energy. Energy is defined as the ability to do work. Doing anything takes energy. A campfire obviously has energy. You can feel its heat and see its light. 
process in which energy changes from one type or form to another,(A) energy (B) kinetic energy (C) energy conversion (D) work (E) gravitational potential energy (F) elastic potential energy (G) potential energy,C,"Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, when wood burns, the woods chemical energy changes to both thermal energy and light energy. Other examples of energy conversions are described in Figure 17.16. You can see still others at this URL: http://fi.edu/guide/hughes/energychangeex.html . You can check your understanding of how energy changes form by doing the quizzes at these URLs:  Energy is conserved in energy conversions. No energy is lost when energy changes form, although some may be released as thermal energy due to friction. For example, not all of the energy put into a steam turbine in Figure 17.16 changes to electrical energy. Some changes to thermal energy because of friction of the turning blades and other moving parts. The more efficient a device is, the greater the percentage of usable energy it produces. Appliances with an ""Energy Star"" label like the one in Figure 17.17 use energy efficiently and thereby reduce energy use. "
The atoms of matter have kinetic energy.,(A) true (B) false,A,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
An objects velocity affects its kinetic energy more than its mass does.,(A) true (B) false,A,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
A heavier object has less gravitational potential energy than a lighter object at the same height.,(A) true (B) false,B,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
Compressing a spring gives it potential energy.,(A) true (B) false,A,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
Energy conversions cannot be reversed.,(A) true (B) false,B,"The law of conservation of energy applies to energy conversions. Energy is not used up when it changes form, although some energy may be used to overcome friction, and this energy is usually given off as heat. For example, the divers kinetic energy at the bottom of his fall is the same as his potential energy when he was on the diving board, except for a small amount of heat resulting from friction with the air as he falls. "
The ability to cause a change in matter is one definition of,(A) work (B) force (C) energy (D) motion,C,"Energy is defined as the ability to cause changes in matter. You can change energy from one form to another when you lift your arm or take a step. In each case, energy is used to move matter  you. The energy of moving matter is called kinetic energy. "
Forms of energy include,(A) mechanical energy (B) electrical energy (C) chemical energy (D) all of the above,D,"Energy, or the ability to cause changes in matter, can exist in many different forms. Energy can also change from one form to another. The photo above of the guitar player represents six forms of energy: mechanical, chemical, electrical, light, thermal, and sound energy. Another form of energy is nuclear energy. Q: Can you find the six different forms of energy in the photo of the guitar player (See opening image)? A: The guitarist uses mechanical energy to pluck the strings of the guitar. He gets the energy he needs to perform from chemical energy in food he ate earlier in the day. The stage lights use electrical energy, which they change to light energy and thermal energy (commonly called heat). The guitar produces sound energy when the guitarist plucks the strings. "
What is the kinetic energy of an object that has a mass of 10 kg and a velocity of 1 m/s?,(A) 100 J (B) 10 J (C) 5J (D) 1J,C,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
What is the gravitational potential energy of an object that has a weight of 12 N and is 3 m above the ground?,(A) 108 J (B) 36 J (C) 15 J (D) 4J,B,"Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in the Figure 1.1. Gravitational potential energy depends on an objects weight and its height above the ground. It can be calculated with the equation: Gravitational potential energy (GPE) = weight  height Consider the little girl on the sled, pictured in the Figure 1.1. She weighs 140 Newtons, and the top of the hill is 4 meters higher than the bottom of the hill. As she sits at the top of the hill, the childs gravitational potential energy is: GPE = 140 N  4 m = 560 N  m Notice that the answer is given in Newton  meters (N  m), which is the SI unit for energy. A Newton  meter is the energy needed to move a weight of 1 Newton over a distance of 1 meter. A Newton  meter is also called a joule (J). Q: The gymnast on the balance beam pictured in the Figure 1.1 weighs 360 Newtons. If the balance beam is 1.2 meters above the ground, what is the gymnasts gravitational potential energy? A: Her gravitational potential energy is: GPE = 360 N  1.2 m = 432 N  m, or 432 J "
Which statement is false about objects with kinetic energy?,(A) They are in motion (B) They are doing work (C) They are moving matter over a distance (D) They are using up their energy by moving,D,"What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo is doing the work of pounding the nail into the board. You can see a cartoon introduction to kinetic energy and its relation to work at this URL:  . The amount of kinetic energy in a moving object depends on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. The kinetic energy of a moving object can be calculated with the equation: 1 Kinetic Energy (KE) = mass  velocity2 2 This equation for kinetic energy shows that velocity affects kinetic energy more than mass does. For example, if mass doubles, kinetic energy also doubles. But if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. You can see for yourself how mass and velocity affect kinetic energy by working through the problems below. Problem Solving Problem: Juan has a mass of 50 kg. If he is running at a velocity of 2 m/s, how much kinetic energy does he have? Solution: Use the formula: KE = 12 mass  velocity2 1 50 kg  (2 m/s2 ) 2 = 100 kg  m2 /s2 = 100 N  m, or 100 J KE = You Try It! Problem: What is Juans kinetic energy if he runs at a velocity of 4 m/s? Problem: Juans dad has a mass of 100 kg. How much kinetic energy does he have if he runs at a velocity of 2 m/s? "
The SI unit for energy is the,(A) joule (B) newton (C) newton  meter (D) two of the above,D,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
Which type(s) of energy does a person have when jumping on a trampoline?,(A) kinetic energy (B) elastic potential energy (C) gravitational potential energy (D) all of the above,D,There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of other examples? 
Most forms of energy can also be classified as kinetic or potential energy.,(A) true (B) false,A,"If you think about different sources of energysuch as batteries and the sunyou probably realize that energy can take different forms. For example, when the boy swings his tennis racket, the energy of the moving racket is an example of mechanical energy. To move his racket, the boy needs energy stored in food, which is an example of chemical energy. Other forms of energy include electrical, thermal, light, and sound energy. The different forms of energy can also be classified as either kinetic energy or potential energy. Kinetic energy is the energy of moving matter. Potential energy is energy that is stored in matter. Q: Is the chemical energy in food kinetic energy or potential energy? A: The chemical energy in food is potential energy. It is stored in the chemical bonds that make up food molecules. The stored energy is released when we digest food. Then we can use it for many purposes, such as moving (mechanical energy) or staying warm (thermal energy). Q: What is an example of kinetic energy? A: Anything that is moving has kinetic energy. An example is a moving tennis racket. "
"If the mass of an object doubles, its kinetic energy is only half as great.",(A) true (B) false,B,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
Kinetic energy and velocity have an inverse relationship.,(A) true (B) false,B,"What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo is doing the work of pounding the nail into the board. You can see a cartoon introduction to kinetic energy and its relation to work at this URL:  . The amount of kinetic energy in a moving object depends on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. The kinetic energy of a moving object can be calculated with the equation: 1 Kinetic Energy (KE) = mass  velocity2 2 This equation for kinetic energy shows that velocity affects kinetic energy more than mass does. For example, if mass doubles, kinetic energy also doubles. But if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. You can see for yourself how mass and velocity affect kinetic energy by working through the problems below. Problem Solving Problem: Juan has a mass of 50 kg. If he is running at a velocity of 2 m/s, how much kinetic energy does he have? Solution: Use the formula: KE = 12 mass  velocity2 1 50 kg  (2 m/s2 ) 2 = 100 kg  m2 /s2 = 100 N  m, or 100 J KE = You Try It! Problem: What is Juans kinetic energy if he runs at a velocity of 4 m/s? Problem: Juans dad has a mass of 100 kg. How much kinetic energy does he have if he runs at a velocity of 2 m/s? "
Clothes hanging motionless on a clothesline do not have any energy.,(A) true (B) false,B,"Evaporation explains why clothes dry on a clothesline. Evaporation is the process in which a liquid changes to a gas without becoming hot enough to boil. It occurs when individual liquid particles at the exposed surface of the liquid absorb just enough energy to overcome the force of attraction with other liquid particles. If the surface particles are moving in the right direction, they will pull away from the liquid and move into the air. This is illustrated in the Figure 1.1. "
Changing the shape of an elastic material gives it potential energy.,(A) true (B) false,A,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
"If you double the weight of an object, its gravitational potential energy also doubles.",(A) true (B) false,A,"Potential energy due to the position of an object above Earth is called gravitational potential energy. Like the leaves on trees, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see examples of people with gravitational potential energy in Figure 17.5. Gravitational potential energy depends on an objects weight and its height above the ground. It can be calculated with the equation: Gravitational potential energy (GPE) = weight  height Consider the diver in Figure 17.5. If he weighs 70 newtons and the diving board is 5 meters above Earths surface, then his potential energy is: GPE = 70 N  5 m = 350 N  m, or 350 J "
"The higher above the ground you are, the less gravitational potential energy you have.",(A) true (B) false,B,"Potential energy due to the position of an object above Earth is called gravitational potential energy. Like the leaves on trees, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see examples of people with gravitational potential energy in Figure 17.5. Gravitational potential energy depends on an objects weight and its height above the ground. It can be calculated with the equation: Gravitational potential energy (GPE) = weight  height Consider the diver in Figure 17.5. If he weighs 70 newtons and the diving board is 5 meters above Earths surface, then his potential energy is: GPE = 70 N  5 m = 350 N  m, or 350 J "
The energy of a child on a swing changes back and forth between kinetic and potential energy.,(A) true (B) false,A,There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of other examples? 
Some of the kinetic energy of the child in question 8 is given off as heat.,(A) true (B) false,A,"What do all the photos in Figure 17.3 have in common? All of them show things that are moving. Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energy from the atoms in matter to the planets in solar systems. Things with kinetic energy can do work. For example, the hammer in the photo is doing the work of pounding the nail into the board. You can see a cartoon introduction to kinetic energy and its relation to work at this URL:  . The amount of kinetic energy in a moving object depends on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. The kinetic energy of a moving object can be calculated with the equation: 1 Kinetic Energy (KE) = mass  velocity2 2 This equation for kinetic energy shows that velocity affects kinetic energy more than mass does. For example, if mass doubles, kinetic energy also doubles. But if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. You can see for yourself how mass and velocity affect kinetic energy by working through the problems below. Problem Solving Problem: Juan has a mass of 50 kg. If he is running at a velocity of 2 m/s, how much kinetic energy does he have? Solution: Use the formula: KE = 12 mass  velocity2 1 50 kg  (2 m/s2 ) 2 = 100 kg  m2 /s2 = 100 N  m, or 100 J KE = You Try It! Problem: What is Juans kinetic energy if he runs at a velocity of 4 m/s? Problem: Juans dad has a mass of 100 kg. How much kinetic energy does he have if he runs at a velocity of 2 m/s? "
Energy conversions are always permanent changes in energy.,(A) true (B) false,B,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
energy released when atomic nuclei split apart,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,C,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
The sum of an objects kinetic and potential energy is its,(A) thermal energy (B) chemical energy (C) mechanical energy (D) none of the above,C,"Mechanical energy is the energy of an object that is moving or has the potential to move. It is the sum of an objects kinetic and potential energy. In Figure 17.9, the basketball has mechanical energy because it is moving. The arrow in the same figure has mechanical energy because it has the potential to move due to the elasticity of the bow. What are some other examples of mechanical energy? "
total kinetic energy of all the atoms in an object,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,D,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
Which form of energy travels in waves through empty space?,(A) sound energy (B) electrical energy (C) electromagnetic energy (D) two of the above,C,"Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). "
energy stored in chemical bonds,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,A,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
Which energy conversion occurs in a battery?,(A) electrical energy  chemical energy (B) electromagnetic energy  light energy (C) chemical energy  light energy (D) chemical energy  electrical energy,D,"Batteries like the one in Figure 23.11 are one of several possible sources of voltage needed to produce electric current. Sources of voltage include generators, chemical cells, and solar cells. Generators change the kinetic energy of a spinning turbine to electrical energy in a process called electromag- netic induction. You can read about generators and how they work in the chapter ""Electromagnetism."" Chemical and solar cells are devices that change chemical or light energy to electrical energy. You can read about both types of cells and how they work below. "
Energy stored in the nucleus of an atom is called,(A) electromagnetic energy (B) electrical energy (C) thermal energy (D) nuclear energy,D,"The nuclei of atoms are held together by powerful forces. This gives them a tremendous amount of stored energy, called nuclear energy. The energy can be released and used to do work. This happens in nuclear power plants when nuclei fission, or split apart. It also happens in the sun and other stars when nuclei fuse, or join together. Some of the suns energy travels to Earth, where it warms the planet and provides the energy for photosynthesis (see Figure "
energy of an object that is moving or has the potential to move,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,F,"Mechanical energy is the energy of an object that is moving or has the potential to move. It is the sum of an objects kinetic and potential energy. In Figure 17.9, the basketball has mechanical energy because it is moving. The arrow in the same figure has mechanical energy because it has the potential to move due to the elasticity of the bow. What are some other examples of mechanical energy? "
energy that travels in waves through matter from a vibrating object,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,G,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
"If two objects have the same mass, which object has greater thermal energy?",(A) The object with larger atomic nuclei (B) The object with faster-moving atoms (C) The object with faster-moving electrons (D) The object with stronger chemical bonds,B,"If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isnt the same thing as thermal energy. Thats because an objects mass also affects its thermal energy. The examples in Figure 18.1 make this clear. In the figure, the particles of cocoa are moving faster than the particles of bathwater. Therefore, the cocoa has a higher temperature. However, the bath water has more thermal energy because there is so much more of it. It has many more moving particles. Bill Nye the Science Guy cleverly discusses these concepts at this URL:  MEDIA Click image to the left or use the URL below. URL:  If youre still not clear about the relationship between temperature and thermal energy, watch the animation ""Tem- perature"" at this URL:  . "
kinetic energy of moving electrons,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,B,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
energy that travels in electrical and magnetic waves,(A) chemical energy (B) electrical energy (C) nuclear energy (D) thermal energy (E) electromagnetic energy (F) mechanical energy (G) sound energy,E,"Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electro- magnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation. Electromagnetic waves can transfer energy through matter or across empty space. Click image to the left or use the URL below. URL:  Q: How do microwaves transfer energy inside a microwave oven? A: They transfer energy through the air inside the oven to the food. "
Stars release electromagnetic energy into space.,(A) true (B) false,A,"Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). "
The energy stored in food is chemical energy.,(A) true (B) false,A,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
"During photosynthesis, plants change thermal energy to chemical energy.",(A) true (B) false,B,"One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6 H2 O  C6 H12 O6 + 6 O2 The energy for photosynthesis comes from light. Without light energy, photosynthesis cannot occur. As you can see in the Figure 1.2, plants can get the energy they need for photosynthesis from either sunlight or artificial light. "
A stretched rubber band has mechanical energy.,(A) true (B) false,A,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
"When you plug in a lamp, electromagnetic energy is converted to light energy.",(A) true (B) false,B,"If youre like most people, you dont give it a thought when you flick a switch to turn on a lightat least not until the power goes out and youre left in the dark! When you flick on a light switch, electricity normally flows through the light, and some type of light bulb converts the electrical energy to visible light. This can happen in various ways, depending on the type of light bulb. Several different types of light bulbs are described below. All of them are examples of artificial light, as opposed to natural light from the sun or other sources in nature. "
Kinetic and potential energy add up to mechanical energy.,(A) true (B) false,A,"Mechanical energy is the energy of an object that is moving or has the potential to move. It is the sum of an objects kinetic and potential energy. In Figure 17.9, the basketball has mechanical energy because it is moving. The arrow in the same figure has mechanical energy because it has the potential to move due to the elasticity of the bow. What are some other examples of mechanical energy? "
There is stored chemical energy in food.,(A) true (B) false,A,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
A lightning bolt is a powerful discharge of light energy.,(A) true (B) false,B,"So much energy collects in cumulonimbus clouds that a huge release of electricity, called lightning, may result (Figure 1.4). The electrical discharge may be between one part of the cloud and another, two clouds, or a cloud and the ground. Lightning heats the air so that it expands explosively. The loud clap is thunder. Light waves travel so rapidly that lightning is seen instantly. Sound waves travel much more slowly, so a thunderclap may come many seconds after the lightning is spotted. Lightning behind the town of Diamond Head, Hawaii. "
Most of the electrical energy we use is produced in power plants.,(A) true (B) false,A,"Electricity originates in power plants. They have electric generators that produce electricity by electromagnetic induction. In this process, a changing magnetic field is used to generate electric current. The generators convert kinetic energy to electrical energy. The kinetic energy may come from flowing water, burning fuel, wind, or some other energy source. "
The sun produces nuclear energy when hydrogen nuclei undergo fusion.,(A) true (B) false,A,"Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. Thats because a great deal of energy is needed to overcome the force of repulsion between positively charged nuclei. The suns energy comes from fusion in its core, where temperatures reach millions of Kelvin (see Figure 11.16). "
Some of the suns energy travels through space to heat and light Earth.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
The atoms that make up matter are in constant motion.,(A) true (B) false,A,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
Radio waves are a type of sound waves.,(A) true (B) false,B,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Energy rarely changes from one form to another.,(A) true (B) false,B,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
One form of energy cannot change into two or more different forms of energy.,(A) true (B) false,B,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
Which form of energy does your body use to stay warm?,(A) light energy (B) sound energy (C) chemical energy (D) none of the above,C,Mammals have a variety of ways to keep their body temperature stable. 
Which type of energy is stored in wood?,(A) thermal energy (B) light energy (C) chemical energy (D) two of the above,C,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
Sources of electrical energy include,(A) the sun (B) lightning (C) batteries (D) two of the above,D,"Batteries like the one in Figure 23.11 are one of several possible sources of voltage needed to produce electric current. Sources of voltage include generators, chemical cells, and solar cells. Generators change the kinetic energy of a spinning turbine to electrical energy in a process called electromag- netic induction. You can read about generators and how they work in the chapter ""Electromagnetism."" Chemical and solar cells are devices that change chemical or light energy to electrical energy. You can read about both types of cells and how they work below. "
Nuclear power plants produce energy by,(A) burning fossil fuels (B) splitting atomic nuclei (C) causing chemical reactions (D) capturing kinetic energy of atoms,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
The thermal energy of an object depends on,(A) how quickly its atoms are moving (B) how much light it gives off (C) how many atoms it has (D) two of the above,D,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
Electromagnetic waves include all of the following except,(A) light (B) sound (C) X rays (D) microwaves,B,"Mid-wavelength electromagnetic waves are commonly called light. This range of electromagnetic waves has shorter wavelengths and higher frequencies than radio waves, but not as short and high as X rays and gamma rays. Light includes visible light, infrared light, and ultraviolet light. If you look back at Figure 21.7, you can see where these different types of light waves fall in the electromagnetic spectrum. "
Sound waves can travel through all of the following except,(A) air (B) space (C) water (D) glass,B,"Sound waves are mechanical waves, so they can travel only though matter and not through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could no longer be heard. Thats because the sound couldnt travel away from the clock without air particles to pass the sound energy along. You can see an online demonstration of the same experimentwith a modern twistat this URL:  (4:06). MEDIA Click image to the left or use the URL below. URL:  Sound waves can travel through many different kinds of matter. Most of the sounds we hear travel through air, but sounds can also travel through liquids such as water and solids such as glass and metal. If you swim underwater or even submerge your ears in bathwater any sounds you hear have traveled to your ears through water. You can tell that sounds travel through glass and other solids because you can hear loud outdoor sounds such as sirens through closed windows and doors. "
Nonrenewable energy resources include,(A) fossil fuels (B) running water (C) radioactive elements (D) two of the above,D,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
All of the following energy resources are fossil fuels except,(A) oil (B) coal (C) biomass (D) natural gas,C,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
Natural gas is used for energy in,(A) motor vehicles (B) water heaters (C) furnaces (D) all of the above,D,"The largest natural gas reserves in the United States are located in the Rocky Mountain states, Texas, and the Gulf of Mexico region. California also has natural gas, mostly in the northern Sacramento Valley and the Sacramento Delta. Natural gas must be processed before it can be used as a fuel. Poisonous chemicals and water must be removed. Natural gas is delivered to homes, where it is used for cooking and heating. Natural gas is also a major energy source for powering turbines to make electricity. Natural gas releases most of its energy as heat when it burns. The power plant is able to use this heat, either in the form of hot gases or steam, to spin turbines. The spinning turbines turn generators, and the generators create electricity. "
Petroleum is used to make,(A) heating oil (B) kerosene (C) gasoline (D) all of the above,D,"Most of the compounds that come out of the refining process are fuels, such as gasoline, diesel, and heating oil. Because these fuels are rich sources of energy and can be easily transported, oil provides about 90% of the energy used for transportation around the world. The rest of the compounds from crude oil are used for waxes, plastics, fertilizers, and other products. Gasoline is in a convenient form for use in cars and other transportation vehicles. In a car engine, the burned gasoline mostly turns into carbon dioxide and water vapor. The fuel releases most of its energy as heat, which causes the gases to expand. This creates enough force to move the pistons inside the engine and to power the car. Refineries like this one separate crude oil into many useful fuels and other chemi- cals. Click image to the left or use the URL below. URL: "
All fossil fuels contain stored chemical energy that came originally from,(A) rocks below Earths surface (B) marine organisms (C) giant tree ferns (D) the sun,D,"When ancient plants underwent photosynthesis, they changed energy in sunlight to stored chemical energy in food. The plants used the food and so did the organisms that ate the plants. After the plants and other organisms died, their remains gradually changed to fossil fuels as they were covered and compressed by layers of sediments. Petroleum and natural gas formed from ocean organisms and are found together. Coal formed from giant tree ferns and other swamp plants. "
Which statement about uranium is true?,(A) It is nearly limitless in supply (B) It is a renewable energy resource (C) It is not as safe to use as solar energy (D) Using it for energy creates air pollution,C,"The Figure 1.2 shows how nuclear fission of uranium-235 occurs. It begins when a uranium nucleus gains a neutron. This can happen naturally when a free neutron strikes it, or it can occur deliberately when a neutron is crashed into it in a nuclear power plant. In either case, the nucleus of uranium-235 becomes extremely unstable with the extra neutron. As a result, it splits into two smaller nuclei, krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. It can be represented by this nuclear equation: 235 U 92 141 + 1 neutron  92 36 Kr + 56 Ba + 3 neutrons + energy Note that the subscripts of the element symbols represent numbers of protons and the superscripts represent numbers of protons plus neutrons. "
What is the function of a wind turbine?,(A) changing the kinetic energy of wind to electrical energy (B) capturing wind energy and using it to pump water (C) slowing down the wind so it causes less erosion (D) storing the energy of wind as thermal energy,A,"Wind power uses moving air as a source of energy. Some types of wind power have been around for a long time. People have used windmills to grind grain and pump water for hundreds of years. Sailing ships have depended on wind for millennia. Wind is now used to generate electricity. Moving air can make a turbine spin, just like moving water can. Moving air has kinetic energy. When wind hits the blades of the turbine, the kinetic energy makes the blades move. The turbine spins and creates electricity. "
The fossil fuel that produces the most carbon dioxide when burned is,(A) oil (B) coal (C) biomass (D) natural gas,B,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
A major drawback of nuclear energy is the production of,(A) air pollution (B) carbon dioxide (C) carbon monoxide (D) radioactive wastes,D,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Geothermal energy,(A) comes from heat below Earths surface (B) cannot be used to produce electricity (C) is only used to heat homes (D) is nonrenewable,A,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
Renewable energy resources include,(A) wind (B) biomass (C) moving water (D) all of the above,D,"Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. Renewable energy resources include sunlight, moving water, wind, biomass, and geothermal energy. Each of these energy resources is described in Table 17.1. Resources such as sunlight and wind are limitless in supply, so they will never run out. Besides their availability, renewable energy resources also have the advantage of producing little if any pollution and not contributing to global warming. The technology needed to gather energy from renewable resources is currently expensive to install, but most of the resources themselves are free for the taking. here? Renewable Energy Resource Sunlight The energy in sunlight, or solar energy, can be used to heat homes. It can also be used to produce electricity in solar cells. However, solar energy may not be practical in areas that are often cloudy. Example Solar panels on the roof of this house generate enough electricity to supply a familys needs. Moving Water When water falls downhill, its potential energy is con- verted to kinetic energy that can turn a turbine and generate electricity. The water may fall naturally over a waterfall or flow through a dam. A drawback of dams is that they flood land upstream and reduce water flow downstream. Either effect may harm ecosystems. Wind Wind is moving air, so it has kinetic energy that can do work. Remember the wind turbines that opened this chapter? Wind turbines change the kinetic energy of the wind to electrical energy. Only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy and unattractive in the landscape. Water flowing through Hoover dam between Arizona and Nevada generates electricity for both of these states and also by southern California. The dam spans the Colorado River. This old-fashioned windmill captures wind energy that is used for pumping water out of a well. Windmills like this one have been used for centuries. Renewable Energy Resource Biomass The stored chemical energy of trees and other plants is called biomass energy. When plant materials are burned, they produce thermal energy that can be used for heating, cooking, or generating electricity. Biomassespecially woodis an important energy source in countries where most people cant afford fossil fuels. Some plants can also be used to make ethanol, a fuel that is added to gasoline. Ethanol produces less pollution than gasoline, but large areas of land are needed to grow the plants needed to make it. Geothermal Heat below Earths surfacecalled geothermal en- ergycan be used to produce electricity. A power plant pumps water underground where it is heated. Then it pumps the water back to the plant and uses its thermal energy to generate electricity. On a small scale, geothermal energy can be used to heat homes. Installing a geothermal system can be very costly, how- ever, because of the need to drill through underground rocks. Example This large machine is harvesting and grinding plants to be used for biomass energy. This geothermal power plant is located in Italy where hot magma is close to the surface. "
Solar cells convert solar energy to,(A) heat (B) steam (C) thermal energy (D) electrical energy,D,Solar cells convert the energy in sunlight to electrical energy. They contain a material such as silicon that absorbs light energy and gives off electrons. The electrons flow and create electric current. Figure 23.13 and the animation at the URL below show how a solar cell uses light energy to produce electric current and power a light bulb. Many calculators and other devices are also powered by solar cells. 
All natural resources need to be conserved so they are not used up.,(A) true (B) false,B,"Especially when it comes to nonrenewable resources, conserving natural resources is important. Using less of them means that they will last longer. It also means they will impact the environment less. Everyone can help make a difference. There are three basic ways that all of us can conserve natural resources. They are referred to as the three Rs: reduce, reuse, and recycle. "
Most of the electricity in the U.S. is generated by burning petroleum.,(A) true (B) false,B,"Figure 20.11 shows the energy resources used in the U.S. The U.S. depends mainly on fossil fuels. Petroleum is used more than any other resource. Renewable energy resources, such as solar and wind energy, could provide all the energy we need, but they are not yet widely used in the U.S. "
The use of fossil fuels is a major cause of global warming.,(A) true (B) false,A,Recent global warming is due mainly to human actions. Burning fossil fuels adds carbon dioxide to the atmosphere. Carbon dioxide is a greenhouse gas. Its one of several that human activities add to the atmosphere. An increase in greenhouse gases leads to greater greenhouse effect. The result is increased global warming. Figure 17.20 shows the increase in carbon dioxide since 1960. 
Nuclear energy is a renewable energy resource.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Natural gas formed when the remains of swamp plants were pressed beneath layers of sediments.,(A) true (B) false,B,"Natural gas forms under the same conditions that create oil. Organic material buried in the sediments harden to become a shale formation that is the source of the gas. Although natural gas forms at higher temperatures than crude oil, the two are often found together. The largest natural gas reserves in the United States are in the Appalachian Basin, North Dakota and Montana, Texas, and the Gulf of Mexico region (Figure 1.1). California also has natural gas, found mostly in the Central Valley. In the northern Sacramento Valley and the Sacramento Delta, a sediment-filled trough formed along a location where crust was pushed together (an ancient convergent margin). Gas production in the lower 48 United States. "
It takes millions of years for fossil fuels to form.,(A) true (B) false,A,"Fossil fuels include coal, oil, and natural gas. Fossil fuels are the greatest energy source for modern society. Millions of years ago, plants used energy from the Sun to form carbon compounds. These compounds were later transformed into coal, oil, or natural gas. Fossil fuels take millions of years to form. For this reason, they are non-renewable. We will use most fossil fuels up in a matter of decades. Burning fossil fuels releases large amounts of pollution. The most important of these may be the greenhouse gas carbon dioxide. "
Most of the electric power in the U.S. is generated from running water.,(A) true (B) false,B,Many of the suitable streams in the United States have been developed for hydroelectric power. Many streams worldwide also have hydroelectric plants. Hydropower is a major source of Californias electricity. It accounts for about 14.5 percent of the total. Most of Californias nearly 400 hydroelectric power plants are located in the Sierra Nevada mountains. 
The burning of fossil fuels leads to the formation of acid rain.,(A) true (B) false,A,"Air pollution may also cause acid rain. This is rain that is more acidic (has a lower pH) than normal rain. Acids form in the atmosphere when nitrogen and sulfur oxides mix with water in air. Nitrogen and sulfur oxides come mainly from motor vehicle exhaust and coal burning. If acid rain falls into lakes, it lowers the pH of the water and may kill aquatic organisms. If it falls on the ground, it may damage soil and soil organisms. If it falls on plants, it may make them sick or even kill them. Acid rain also damages stone buildings, bridges, and statues, like the one in Figure 25.1. "
It takes a large amount of uranium to produce a small amount of nuclear energy.,(A) true (B) false,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
Renewable energy resources produce air pollution.,(A) true (B) false,B,"Nonrenewable energy resources will run out before long. Using these energy resources also produces pollution and increases global warming. For all these reasons, we need to use less of these energy sources. We also need to use them more efficiently. "
Fossil fuels provide most of the worlds energy.,(A) true (B) false,A,"Fossil fuels provide about 85% of the worlds energy at this time. Worldwide fossil fuel usage has increased many times over in the past half century (coal - 2.6x, oil - 8x, natural gas - 14x) because of population increases, because of increases in the number of cars, televisions, and other fuel-consuming uses in the developed world, and because of lifestyle improvements in the developing world. The amount of fossil fuels that remain untapped is unknown, but can likely be measured in decades for oil and natural gas and in a few centuries for coal (Figure 1.1). "
Coal and petroleum are often found together.,(A) true (B) false,B,Natural gas is often found along with coal or oil in underground deposits. This is because natural gas forms with these other fossil fuels. One difference between natural gas and oil is that natural gas forms at higher temperatures. 
Smog comes from the burning of fossil fuels.,(A) true (B) false,A,Most pollutants enter the air when fossil fuels burn. Some are released when forests burn. Others evaporate into the air. 
Using moving water to generate electricity never harms the environment.,(A) true (B) false,B,"Water power does not burn a fuel. So it causes less pollution than many other kinds of energy. Water power is also a renewable resource. Water keeps flowing downhill. Although we use some of the energy from this movement, we are not using up the water. Water power does have problems. A large dam stops a streams flow, which floods the land upstream. A beautiful location may be lost. People may be displaced. The dams and turbines also change the downstream environment. Fish and other living things may not be able to survive. Dams slow the release of silt. Downstream deltas retreat and beaches may be starved of sand. Seaside cities may become exposed to storms and rising sea levels. Tidal power stations may need to close off a narrow bay or estuary. Wave power plants must withstand coastal storms and the corrosion of seawater. "
Wind turbines change the kinetic energy of wind to electrical energy.,(A) true (B) false,A,"Wind power uses moving air as a source of energy. Some types of wind power have been around for a long time. People have used windmills to grind grain and pump water for hundreds of years. Sailing ships have depended on wind for millennia. Wind is now used to generate electricity. Moving air can make a turbine spin, just like moving water can. Moving air has kinetic energy. When wind hits the blades of the turbine, the kinetic energy makes the blades move. The turbine spins and creates electricity. "
saving resources by using them more efficiently,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,A,We can reduce our use of energy resources and the pollution they cause by conserving energy. Conservation means saving resources by using them more efficiently or not using them at all. Figure 17.24 shows several ways that people can conserve energy in their daily lives. You can find more energy-saving tips at the URL below. What do you do to save energy? What else could you do? 
resource that is limited in supply and cannot be replaced,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,G,Nonrenewable resources are natural resources that are limited in supply and cannot be replaced except over millions of years. Nonrenewable energy resources include fossil fuels and radioactive elements such as uranium. 
energy from plant materials,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,D,"Biomass is another renewable source of energy. Biomass includes wood, grains, and other plant materials or waste materials. People can burn wood directly for energy in the form of heat. Biomass can also be processed to make biofuel. Biofuel is a fairly new type of energy that is becoming more popular. Biomass is useful because it can be made liquid. This means that they can be used in cars and trucks. Some car engines can be powered by pure vegetable oil or even recycled vegetable oil. Sometimes the exhaust from these cars smells like French fries! By using biofuels, we can cut down on the amount of fossil fuel that we use. Because living plants take carbon dioxide out of the air, growing plants for biofuel can mean that we will put less of this gas into the air overall. This could help us do something about the problem of global warming. "
mixture of hydrocarbons that formed from the remains of dead organisms,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,C,"Oil from the ground is called crude oil, which is a mixture of many different hydrocarbons. Crude oil is a thick dark brown or black liquid hydrocarbon. Oil also forms from buried dead organisms, but these are tiny organisms that live on the sea surface and then sink to the seafloor when they die. The dead organisms are kept away from oxygen by layers of other dead creatures and sediments. As the layers pile up, heat and pressure increase. Over millions of years, the dead organisms turn into liquid oil. "
heat from below Earths surface that can be used for energy,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,F,"Geothermal energy comes the Earths internal heat. Hot springs and geysers are produced by water that is heated by magma or hot rock below the surface. At a geothermal power plant, engineers drill wells into the hot rocks. Hot water or steam may come up through the wells. Alternatively, water may be put down into the well to be heated. It then comes up. The hot water or steam makes a turbine spin. This makes electricity. "
anything people use that comes from nature,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,B,"Economically, there are many direct benefits of biodiversity. As many as 40,000 species of fungi, plants, and animals provide us with many varied types of clothing, shelter, medicines and other products. These include poisons, timber, fibers, fragrances, papers, silks, dyes, adhesives, rubber, resins, skins, furs, and more. According to one survey, 57% of the most important prescription drugs come from nature. Specifically, they come from bacteria, fungi, plants, and animals ( Figure 1.2). But only a small amount of species with the ability to give us medicines have been explored. The loss of any species may mean the loss of new medicines, which will have a direct effect on human health. Aspirin originally came from the bark of the white willow tree, pictured here. "
resource that is virtually limitless in supply or can be replaced quickly,(A) conservation (B) natural resource (C) fossil fuel (D) biomass energy (E) renewable resource (F) geothermal energy (G) nonrenewable resource,E,"From the table in the concept ""Materials Humans Use,"" you can see that many of the resources we depend on are non-renewable. Non-renewable resources vary in their availability; some are very abundant and others are rare. Materials, such as gravel or sand, are technically non-renewable, but they are so abundant that running out is no issue. Some resources are truly limited in quantity: when they are gone, they are gone, and something must be found that will replace them. There are even resources, such as diamonds and rubies, that are valuable in part because they are so rare. "
device for measuring temperature,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,D,"Thermometers measure temperature. In an old-style mercury thermometer, mercury is placed in a long, very narrow tube with a bulb. Because mercury is temperature sensitive, it expands when temperatures are high and contracts when they are low. A scale on the outside of the thermometer matches up with the air temperature. Some modern thermometers use a coiled strip composed of two kinds of metal, each of which conducts heat differently. As the temperature rises and falls, the coil unfolds or curls up tighter. Other modern thermometers measure infrared radiation or electrical resistance. Modern thermometers usually produce digital data that can be fed directly into a computer. "
What happens to water when you heat it?,(A) The particles of the water gain kinetic energy (B) The thermal energy of the water increases (C) The temperature of the water rises (D) all of the above,D,"If you fill a pot with cool tap water and place the pot on a hot stovetop, the water heats up. Heat energy travels from the stovetop to the pot, and the water absorbs the energy from the pot. What happens to the water next? "
total kinetic energy of particles of matter,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,A,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
What causes the liquid in a thermometer to rise?,(A) The liquid expands (B) The liquid turns to a gas (C) The liquid increases in mass (D) The liquid has greater specific heat,A,"Many thermometers measure temperature with a liquid that expands when it gets warmer and contracts when it gets cooler. Look at the common household thermometer pictured in the Figure 1.1. The red liquid rises or falls in the glass tube as the temperature changes. Temperature is read off the scale at the height of the liquid in the tube. Q: Why does the liquid in the thermometer expand and contract when temperature changes? A: When the temperature is higher, particles of the liquid have greater kinetic energy, so they move about more and spread apart. This causes the liquid to expand. The opposite happens when the temperature is lower and particles of liquid have less kinetic energy. The particles move less and crowd closer together, causing the liquid to contract. "
amount of energy needed to raise the temperature of 1 gram of a substance by 1 C,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,G,Specific heat is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of energy (in joules) needed to raise the temperature of 1 gram of the substance by 1  C. Specific heat is a property that is specific to a given type of matter. Thats why its called specific. 
"When heat is transferred between objects of different temperatures, what is the end result?",(A) Both objects have a higher temperature (B) Both objects have a lower temperature (C) Both objects have the same temperature (D) The difference in temperature is greater,C,"Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temperature to an object with a lower temperature. When thermal energy is transferred in this way, the warm object becomes cooler and the cool object becomes warmer. Sooner or later, both objects will have the same temperature. Only then does the transfer of thermal energy end. For a visual explanation of these concepts, watch the animation ""Temperature vs. Heat"" at this URL:  . "
Why does the sand on a beach get so much warmer than the water on a sunny day?,(A) The particles of sand are smaller (B) The sand has higher specific heat (C) The water has less thermal energy (D) The water has greater specific heat,D,"The girls in Figure 18.4 are having fun at the beach. Its a warm, sunny day, and the sand feels hot under their bare hands and feet. The water, in contrast, feels much cooler. Why does the sand get so hot while the water does not? The answer has to do with specific heat. Specific heat is the amount of energy (in joules) needed to raise the temperature of 1 gram of a substance by 1C. Specific heat is a property that is specific to a given type of matter. Table 18.1 lists the specific heat of four different substances. Metals such as iron have relatively low specific heat. It doesnt take much energy to raise their temperature. Thats why a metal spoon heats up quickly when placed in hot coffee. Sand also has a relatively low specific heat, whereas water has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land also affect climate. To learn how, watch the video at this URL:  MEDIA Click image to the left or use the URL below. URL:  In Table 18.1, how much greater is the specific heat of water than sand? Substances iron sand wood water Specific Heat (joules) 0.45 0.67 1.76 4.18 "
average kinetic energy of particles of matter,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,C,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
scale for measuring temperature,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,F,"The thermometer pictured in the Figure 1.1 measures temperature on two different scales: Celsius (C) and Fahrenheit (F). Although some scientists use the Celsius scale, the SI scale for measuring temperature is the Kelvin scale. If you live in the U.S., you are probably most familiar with the Fahrenheit scale. The Table 1.1 compares all three temperature scales. Each scale uses as reference points the freezing and boiling points of water. Notice that temperatures on the Kelvin scale are not given in degrees ( ). Scale Kelvin Celsius Fahrenheit Freezing Point of Water 273 K 0 C 32  F Boiling Point of Water 373 K 100  C 212  F Because all three temperature scales are frequently used, its useful to know how to convert temperatures from one scale to another. Its easy to convert temperatures between the Kelvin and Celsius scales. Each 1-degree change on the Kelvin scale is equal to a 1-degree change on the Celsius scale. Therefore, to convert a temperature from Celsius to Kelvin, just add 273 to the Celsius temperature. For example, 10  C equals 283 Kelvin. Q: How would you convert a temperature from Kelvin to Celsius? A: You would subtract 273 from the Kelvin temperature. For example, a temperature of 300 Kevin equals 27  C. Converting between Celsius and Fahrenheit is more complicated. The following conversion factors can be used: Celsius  Fahrenheit: ( C  1.8) + 32 =  F Fahrenheit  Celsius: ( F - 32)  1.8 =  C 3. Assume that the temperature outside is 293 Kelvin but youre familiar only with the Fahrenheit scale. Do you need to wear a hat and gloves when you go outside? To find out, convert the Kelvin temperature to Fahrenheit. (Hint: Convert the Kelvin temperature to Celsius first.) "
Specific heat is measured in,(A) grams (B) degrees (C) joules (D) newtons,C,Specific heat is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of energy (in joules) needed to raise the temperature of 1 gram of the substance by 1  C. Specific heat is a property that is specific to a given type of matter. Thats why its called specific. 
transfer of thermal energy between objects with different temperatures,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,B,"Conduction is the transfer of thermal energy between particles of matter that are touching. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Conduction is one of three ways that thermal energy can be transferred (the other ways are convection and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. "
measure that affects the thermal energy of matter but not its temperature,(A) thermal energy (B) heat (C) temperature (D) thermometer (E) mass (F) Celsius (G) specific heat,E,"If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isnt the same thing as thermal energy. Thats because an objects mass also affects its thermal energy. The examples in Figure 18.1 make this clear. In the figure, the particles of cocoa are moving faster than the particles of bathwater. Therefore, the cocoa has a higher temperature. However, the bath water has more thermal energy because there is so much more of it. It has many more moving particles. Bill Nye the Science Guy cleverly discusses these concepts at this URL:  MEDIA Click image to the left or use the URL below. URL:  If youre still not clear about the relationship between temperature and thermal energy, watch the animation ""Tem- perature"" at this URL:  . "
The particles of all matter are in constant random motion.,(A) true (B) false,A,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
Objects with the same temperature always have the same total kinetic energy.,(A) true (B) false,B,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
A thermometer measures temperature relative to two reference temperatures.,(A) true (B) false,A,"Thermometers measure temperature. In an old-style mercury thermometer, mercury is placed in a long, very narrow tube with a bulb. Because mercury is temperature sensitive, it expands when temperatures are high and contracts when they are low. A scale on the outside of the thermometer matches up with the air temperature. Some modern thermometers use a coiled strip composed of two kinds of metal, each of which conducts heat differently. As the temperature rises and falls, the coil unfolds or curls up tighter. Other modern thermometers measure infrared radiation or electrical resistance. Modern thermometers usually produce digital data that can be fed directly into a computer. "
Heat is always transferred from a larger object to a smaller object.,(A) true (B) false,B,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
Differences in the specific heat of land and water affect climate.,(A) true (B) false,A,"When a place is near an ocean, the water can have a big effect on the climate. "
Only warm or hot objects have thermal energy.,(A) true (B) false,B,"Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temperature to an object with a lower temperature. When thermal energy is transferred in this way, the warm object becomes cooler and the cool object becomes warmer. Sooner or later, both objects will have the same temperature. Only then does the transfer of thermal energy end. For a visual explanation of these concepts, watch the animation ""Temperature vs. Heat"" at this URL:  . "
"If particles of an object start to move more quickly, the objects temperature rises.",(A) true (B) false,A,"No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. With a higher temperature, matter feels warmer. When particles move more slowly, they have less kinetic energy on average, so their temperature is lower. With a lower temperature, matter feels cooler. "
Temperature is the same thing as thermal energy.,(A) true (B) false,B,"Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temperature to an object with a lower temperature. When thermal energy is transferred in this way, the warm object becomes cooler and the cool object becomes warmer. Sooner or later, both objects will have the same temperature. Only then does the transfer of thermal energy end. For a visual explanation of these concepts, watch the animation ""Temperature vs. Heat"" at this URL:  . "
An object with a higher temperature always has greater thermal energy than an object with a lower,(A) true (B) false,B,"If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isnt the same thing as thermal energy. Thats because an objects mass also affects its thermal energy. The examples in Figure 18.1 make this clear. In the figure, the particles of cocoa are moving faster than the particles of bathwater. Therefore, the cocoa has a higher temperature. However, the bath water has more thermal energy because there is so much more of it. It has many more moving particles. Bill Nye the Science Guy cleverly discusses these concepts at this URL:  MEDIA Click image to the left or use the URL below. URL:  If youre still not clear about the relationship between temperature and thermal energy, watch the animation ""Tem- perature"" at this URL:  . "
"On the Celsius scale, the boiling point of water is 32 C.",(A) true (B) false,B,"The SI scale for measuring temperature is the Kelvin scale. However, some scientists use the Celsius scale instead. If you live in the U.S., you are probably more familiar with the Fahrenheit scale. Table 2.3 compares all three temperature scales. What is the difference between the boiling and freezing points of water on each of these scales? Scale Kelvin Celsius Fahrenheit Freezing Point of Water 273 K 0C 32F Boiling Point of Water 373 K 100C 212F Each 1-degree change on the Kelvin scale is equal to a 1-degree change on the Celsius scale. This makes it easy to convert measurements between Kelvin and Celsius. For example, to go from Celsius to Kelvin, just add 273. How would you convert a temperature from Kelvin to Celsius? Converting between Celsius and Fahrenheit is more complicated. The following conversion factors are used: Celsius ! Fahrenheit : ( C  1.8) + 32 = F Fahrenheit ! Celsius : ( F 32)  1.8 = C Problem Solving Problem: Convert 10C to Fahrenheit. Solution: (10C  1.8) + 32 = 50F You Try It! Problem: The weather forecaster predicts a high temperature today of 86F. What will the temperature be in Celsius? "
Most types of matter expand to some degree when they get warmer.,(A) true (B) false,A,"Temperature is measured with a thermometer. A thermometer shows how hot or cold something is relative to two reference temperatures, usually the freezing and boiling points of water. Scientists often use the Celsius scale for temperature. On this scale, the freezing point of water is 0C and the boiling point is 100C. To learn more about measuring temperature, watch the animation Measuring Temperature at this URL:  Did you ever wonder how a thermometer works? Look at the thermometer in Figure 18.2. Particles of the red liquid have greater energy when they are warmer, so they move more and spread apart. This causes the liquid to expand and rise higher in the glass tube. Like the liquid in a thermometer, most types of matter expand to some degree when they get warmer. Gases usually expand the most when heated, followed by liquids. Solids generally expand the least. (Water is an exception; it takes up more space as a solid than as a liquid.) "
Temperature is a physical property of matter.,(A) true (B) false,B,"Matter has many properties. Some are physical properties. Physical properties of matter are properties that can be measured or observed without matter changing to a different substance. For example, whether a given substance normally exists as a solid, liquid, or gas is a physical property. Consider water. It is a liquid at room temperature, but if it freezes and changes to ice, it is still water. Generally, physical properties are things you can see, hear, smell, or feel with your senses. "
Thermal energy always moves from an object with a higher temperature to an object with a lower,(A) true (B) false,A,"Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temperature to an object with a lower temperature. When thermal energy is transferred in this way, the warm object becomes cooler and the cool object becomes warmer. Sooner or later, both objects will have the same temperature. Only then does the transfer of thermal energy end. For a visual explanation of these concepts, watch the animation ""Temperature vs. Heat"" at this URL:  . "
Specific heat is a property that is specific to a given type of matter.,(A) true (B) false,A,Specific heat is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of energy (in joules) needed to raise the temperature of 1 gram of the substance by 1  C. Specific heat is a property that is specific to a given type of matter. Thats why its called specific. 
Most metals have a very high specific heat.,(A) true (B) false,B,"The Table 1.1 compares the specific heat of four different substances. Metals such as iron have low specific heat. It doesnt take much energy to raise their temperature. Thats why a metal spoon heats up quickly when placed in a cup of hot coffee. Sand also has a relatively low specific heat. Water, on the other hand, has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land even affect climate. Substance iron sand wood Specific Heat (joules) 0.45 0.67 1.76 Q: Metal cooking pots and pans often have wooden handles. Can you explain why? A: Wood has a higher specific heat than metal, so it takes more energy to heat a wooden handle than a metal handle. As a result, a wooden handle would heat up more slowly and be less likely to burn your hand when you touch it. "
"If two objects have the same mass, the object with the higher temperature always",(A) has greater thermal energy (B) has higher specific heat (C) feels warmer (D) two of the above,D,"If two objects have the same mass, the object with the higher temperature has greater thermal energy. Temperature affects thermal energy, but temperature isnt the same thing as thermal energy. Thats because an objects mass also affects its thermal energy. The examples in Figure 18.1 make this clear. In the figure, the particles of cocoa are moving faster than the particles of bathwater. Therefore, the cocoa has a higher temperature. However, the bath water has more thermal energy because there is so much more of it. It has many more moving particles. Bill Nye the Science Guy cleverly discusses these concepts at this URL:  MEDIA Click image to the left or use the URL below. URL:  If youre still not clear about the relationship between temperature and thermal energy, watch the animation ""Tem- perature"" at this URL:  . "
Which of the following statements about temperature is true?,(A) Temperature measures heat (B) Temperature measures kinetic energy (C) Temperature is the same thing as heat (D) Temperature is the same thing as thermal energy,B,"No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. With a higher temperature, matter feels warmer. When particles move more slowly, they have less kinetic energy on average, so their temperature is lower. With a lower temperature, matter feels cooler. "
"If a bucket full of water and a cup full of water have the same temperature, then the water in the",(A) bucket and cup have the same thermal energy (B) bucket has greater thermal energy (C) cup has lower average kinetic energy (D) cup has lower specific heat,B,"Temperature is measured with a thermometer. A thermometer shows how hot or cold something is relative to two reference temperatures, usually the freezing and boiling points of water. Scientists often use the Celsius scale for temperature. On this scale, the freezing point of water is 0C and the boiling point is 100C. To learn more about measuring temperature, watch the animation Measuring Temperature at this URL:  Did you ever wonder how a thermometer works? Look at the thermometer in Figure 18.2. Particles of the red liquid have greater energy when they are warmer, so they move more and spread apart. This causes the liquid to expand and rise higher in the glass tube. Like the liquid in a thermometer, most types of matter expand to some degree when they get warmer. Gases usually expand the most when heated, followed by liquids. Solids generally expand the least. (Water is an exception; it takes up more space as a solid than as a liquid.) "
The thermal energy of an object depends on its,(A) mass (B) temperature (C) specific heat (D) two of the above,D,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
"If you put a cool spoon into a cup of hot coffee, the temperature of the spoon rises because",(A) thermal energy is transferred from the coffee to the spoon (B) specific heat is transferred from the coffee to the spoon (C) particles of the spoon gain kinetic energy (D) two of the above,D,"Figure 18.3 illustrates an example of thermal energy transfer. Before the spoon was put into the steaming hot coffee, it was cool to the touch. Once in the coffee, the spoon heated up quickly. The fast-moving particles of the coffee transferred some of their energy to the slower-moving particles of the spoon. The spoon particles started moving faster and became warmer, causing the temperature of the spoon to rise. Because the coffee particles lost some of their kinetic energy to the spoon particles, the coffee particles started to move more slowly. This caused the temperature of the coffee to fall. Before long, the coffee and spoon had the same temperature. "
Which of the following materials has the greatest specific heat?,(A) iron (B) sand (C) wood (D) water,D,"The Table 1.1 compares the specific heat of four different substances. Metals such as iron have low specific heat. It doesnt take much energy to raise their temperature. Thats why a metal spoon heats up quickly when placed in a cup of hot coffee. Sand also has a relatively low specific heat. Water, on the other hand, has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land even affect climate. Substance iron sand wood Specific Heat (joules) 0.45 0.67 1.76 Q: Metal cooking pots and pans often have wooden handles. Can you explain why? A: Wood has a higher specific heat than metal, so it takes more energy to heat a wooden handle than a metal handle. As a result, a wooden handle would heat up more slowly and be less likely to burn your hand when you touch it. "
A material with greater specific heat,(A) warms up more quickly (B) requires less energy to get hot (C) always has a higher temperature (D) none of the above,D,"The Table 1.1 compares the specific heat of four different substances. Metals such as iron have low specific heat. It doesnt take much energy to raise their temperature. Thats why a metal spoon heats up quickly when placed in a cup of hot coffee. Sand also has a relatively low specific heat. Water, on the other hand, has a very high specific heat. It takes a lot more energy to increase the temperature of water than sand. This explains why the sand on a beach gets hot while the water stays cool. Differences in the specific heat of water and land even affect climate. Substance iron sand wood Specific Heat (joules) 0.45 0.67 1.76 Q: Metal cooking pots and pans often have wooden handles. Can you explain why? A: Wood has a higher specific heat than metal, so it takes more energy to heat a wooden handle than a metal handle. As a result, a wooden handle would heat up more slowly and be less likely to burn your hand when you touch it. "
material that allows little if any conduction of thermal energy,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,D,"Particles of gases are farther apart and have fewer collisions, so they are not good at transferring thermal energy. Materials that are poor thermal conductors are called thermal insulators. Figure 18.7 shows several examples. Fluffy yellow insulation inside the roof of a home is full of air. The air prevents the transfer of thermal energy into the house on hot days and out of the house on cold days. A puffy down jacket keeps you warm in the winter for the same reason. Its feather filling holds trapped air that prevents energy transfer from your warm body to the cold air outside. Solids like plastic and wood are also good thermal insulators. Thats why pot handles and cooking utensils are often made of these materials. "
Conduction is usually slowest in,(A) gases (B) solids (C) liquids (D) flames,A,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
transfer of thermal energy by waves that can travel through space,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,E,"Radiation is the transfer of energy by waves. Energy can travel as waves through air or empty space. The Suns energy travels through space by radiation. After sunlight heats the planets surface, some heat radiates back into the atmosphere. "
Which of the following materials is a thermal insulator?,(A) plastic (B) iron (C) copper (D) steel,A,"Particles of gases are farther apart and have fewer collisions, so they are not good at transferring thermal energy. Materials that are poor thermal conductors are called thermal insulators. Figure 18.7 shows several examples. Fluffy yellow insulation inside the roof of a home is full of air. The air prevents the transfer of thermal energy into the house on hot days and out of the house on cold days. A puffy down jacket keeps you warm in the winter for the same reason. Its feather filling holds trapped air that prevents energy transfer from your warm body to the cold air outside. Solids like plastic and wood are also good thermal insulators. Thats why pot handles and cooking utensils are often made of these materials. "
flow of particles in a fluid due to differences in temperature and density,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,F,"The Figure 1.1 shows how convection occurs, using hot water in a pot as an example. When particles in one area of a fluid (in this case, the water at the bottom of the pot) gain thermal energy, they move more quickly, have more collisions, and spread farther apart. This decreases the density of the particles, so they rise up through the fluid. As they rise, they transfer their thermal energy to other particles of the fluid and cool off in the process. With less energy, the particles move more slowly, have fewer collisions, and move closer together. This increases their density, so they sink back down through the fluid. When they reach the bottom of the fluid, the cycle repeats. The result is a loop of moving particles called a convection current. "
In which substance can thermal energy be transferred by convection?,(A) air (B) sand (C) wood (D) two of the above,A,"Convection is the transfer of thermal energy by particles moving through a fluid (either a gas or a liquid). Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Convection is one of three ways that thermal energy can be transferred (the other ways are conduction and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Thermal energy is transferred through the ocean by,(A) currents (B) waves (C) winds (D) tides,A,"Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earths surface, through water in the oceans, and through air in the atmosphere. Convection currents in the atmosphere create winds. You can see one way this happens in the Figure 1.2. The land heats up and cools off faster than the water because it has lower specific heat. Therefore, the land gets warmer during the day and cooler at night than the water does. During the day, warm air rises above the land and cool air from the water moves in to take its place. During the night, the opposite happens. Warm air rises above the water and cool air from the land moves out to take its place. Q: During the day, in which direction is thermal energy of the air transferred? In which direction is it transferred during the night? A: During the day, thermal energy is transferred from the air over the land to the air over the water. During the night, thermal energy is transferred in the opposite direction. "
material that is good at transferring thermal energy by conduction,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,B,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
amount of mass in a given volume of matter,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,G,"The density of matter is actually the amount of matter in a given space. The amount of matter is measured by its mass. The space matter takes up is measured by its volume. Therefore, the density of matter can be calculated with this formula: Density = mass volume Assume, for example, that a book has a mass of 500 g and a volume of 1000 cm3 . Then the density of the book is: Density = 500 g = 0.5 g/cm3 1000 cm3 Q: What is the density of a liquid that has a volume of 30 mL and a mass of 300 g? A: The density of the liquid is: Density = 300 g = 10 g/mL 30 mL "
Matter is not needed for the transfer of thermal energy by,(A) conduction (B) convection (C) radiation (D) two of the above,C,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
transfer of thermal energy between particles of matter that are touching,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,A,"Conduction is the transfer of thermal energy between particles of matter that are touching. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Conduction is one of three ways that thermal energy can be transferred (the other ways are convection and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. "
transfer of thermal energy by particles moving through a fluid,(A) conduction (B) thermal conductor (C) convection (D) thermal insulator (E) radiation (F) convection current (G) density,C,"Convection is the transfer of thermal energy by particles moving through a fluid (either a gas or a liquid). Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Convection is one of three ways that thermal energy can be transferred (the other ways are conduction and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Conduction occurs when particles of matter flow.,(A) true (B) false,B,"Conduction is the transfer of thermal energy between particles of matter that are touching. When energetic particles collide with nearby particles, they transfer some of their thermal energy. From particle to particle, like dominoes falling, thermal energy moves throughout a substance. In Figure 18.5, conduction occurs between particles of the metal in the pot and between particles of the pot and the water. Figure 18.6 shows additional examples of conduction. For a deeper understanding of this method of heat transfer, watch the animation ""Conduction"" at this URL: http://w "
Insulation can keep a house cool on a hot day.,(A) true (B) false,A,"One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators. Down-filled snowsuits, like those in the Figure 1.2, are good thermal insulators because their feather filling traps a lot of air. Another example of a thermal insulator is pictured in the Figure 1.3. The picture shows fluffy pink insulation inside the attic of a home. Like the down filling in a snowsuit, the insulation traps a lot of air. The insulation helps to prevent the transfer of thermal energy into the house on hot days and out of the house on cold days. Other materials that are thermal insulators include plastic and wood. Thats why pot handles and cooking utensils are often made of these materials. Notice that the outside of the toaster pictured in the opening image is made of plastic. The plastic casing helps prevent the transfer of thermal energy from the heating element inside to the outer surface of the toaster where it could cause burns. Q: Thermal insulators have many practical uses besides the uses mentioned above. Can you think of others? A: Thermal insulators are often used to keep food or drinks hot or cold. For example, Styrofoam coolers and thermos containers are used for these purposes. "
Thermal energy is always transferred from cooler to warmer objects.,(A) true (B) false,B,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
Land and sea breezes are examples of convection currents.,(A) true (B) false,A,"Convection is the transfer of thermal energy by particles moving through a fluid. Particles transfer energy by moving from warmer to cooler areas. Thats how energy is transferred in the soup in Figure 18.7. Particles of soup near the bottom of the pot get hot first. They have more energy so they spread out and become less dense. With lower density, these particles rise to the top of the pot (see Figure 18.8). By the time they reach the top of the pot they have cooled off. They have less energy to move apart, so they become denser. With greater density, the particles sink to the bottom of the pot, and the cycle repeats. This loop of moving particles is called a convection current. Convection currents move thermal energy through many fluids, including molten rock inside Earth, water in the oceans, and air in the atmosphere. In the atmosphere, convection currents create wind. You can see one way this happens in Figure 18.9. Land heats up and cools off faster than water because it has lower specific heat. Therefore, land is warmer during the day and cooler at night than water. Air close to the surface gains or loses heat as well. Warm air rises because it is less dense, and when it does, cool air moves in to take its place. This creates a convection current that carries air from the warmer to the cooler area. You can learn more about convection currents by watching ""Convection"" at this URL:  . "
Only hot objects radiate thermal energy.,(A) true (B) false,B,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
A pot resting on a hot stovetop heats up because of,(A) convection (B) conduction (C) radiation (D) all of the above,B,"If you fill a pot with cool tap water and place the pot on a hot stovetop, the water heats up. Heat energy travels from the stovetop to the pot, and the water absorbs the energy from the pot. What happens to the water next? "
Your hand feels cold when you hold an ice cube because,(A) the ice radiates cold to your hand (B) the ice conducts cold to your hand (C) your hand cools down by convection (D) your hand transfers thermal energy to the ice,D,Think about how you would make ice cubes in a tray. First you would fill the tray with water from a tap. Then you would place the tray in the freezer compartment of a refrigerator. The freezer is very cold. What happens next? 
In which of the following materials does conduction occur most quickly?,(A) iron (B) wood (C) plastic (D) oxygen,A,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
Examples of thermal insulators include,(A) down feathers (B) Styrofoam (C) air (D) all of the above,D,"One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators. Down-filled snowsuits, like those in the Figure 1.2, are good thermal insulators because their feather filling traps a lot of air. Another example of a thermal insulator is pictured in the Figure 1.3. The picture shows fluffy pink insulation inside the attic of a home. Like the down filling in a snowsuit, the insulation traps a lot of air. The insulation helps to prevent the transfer of thermal energy into the house on hot days and out of the house on cold days. Other materials that are thermal insulators include plastic and wood. Thats why pot handles and cooking utensils are often made of these materials. Notice that the outside of the toaster pictured in the opening image is made of plastic. The plastic casing helps prevent the transfer of thermal energy from the heating element inside to the outer surface of the toaster where it could cause burns. Q: Thermal insulators have many practical uses besides the uses mentioned above. Can you think of others? A: Thermal insulators are often used to keep food or drinks hot or cold. For example, Styrofoam coolers and thermos containers are used for these purposes. "
The transfer of thermal energy by convection occurs only in,(A) gases (B) solids (C) fluids (D) liquids,C,"Convection is the transfer of thermal energy by particles moving through a fluid (either a gas or a liquid). Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Convection is one of three ways that thermal energy can be transferred (the other ways are conduction and thermal radiation). Thermal energy is always transferred from matter with a higher temperature to matter with a lower temperature. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
Thermal energy is transferred throughout the ocean by,(A) radiation (B) conduction (C) thermal conductors (D) convection currents,D,"Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earths surface, through water in the oceans, and through air in the atmosphere. Convection currents in the atmosphere create winds. You can see one way this happens in the Figure 1.2. The land heats up and cools off faster than the water because it has lower specific heat. Therefore, the land gets warmer during the day and cooler at night than the water does. During the day, warm air rises above the land and cool air from the water moves in to take its place. During the night, the opposite happens. Warm air rises above the water and cool air from the land moves out to take its place. Q: During the day, in which direction is thermal energy of the air transferred? In which direction is it transferred during the night? A: During the day, thermal energy is transferred from the air over the land to the air over the water. During the night, thermal energy is transferred in the opposite direction. "
A sea breeze blows,(A) toward the land (B) toward the sea (C) only at night (D) during both day and night,A,Ocean water is slower to warm up and cool down than land. So the sea surface is cooler than the land in the daytime. It is also cooler than the land in the summer. The opposite is also true. The water stays warmer than the land during the night and the winter. These differences in heating cause local winds known as land and sea breezes. Land and sea breezes are illustrated in Figure 15.20. A sea breeze blows from sea to land during the day or in summer. Thats when air over the land is warmer than air over the water. The warm air rises. Cool air from over the water flows in to take its place. A land breeze blows from land to sea during the night or in winter. Thats when air over the water is warmer than air over the land. The warm air rises. Cool air from the land flows out to take its place. 
Conduction occurs only between particles that collide.,(A) true (B) false,A,"To understand how conduction works, you need to think about the tiny particles that make up matter. The particles of all matter are in constant random motion, but the particles of warmer matter have more energy and move more quickly than the particles of cooler matter. When particles of warmer matter collide with particles of cooler matter, they transfer some of their thermal energy to the cooler particles. From particle to particle, like dominoes falling, thermal energy moves through matter. In the opening photo above, conduction occurs between particles of metal in the cookie sheet and anything cooler that comes into contact with ithopefully, not someones bare hands! "
Wood is an example of a good thermal conductor.,(A) true (B) false,B,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
Home insulation prevents the transfer of cold into the house.,(A) true (B) false,B,"One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators. Down-filled snowsuits, like those in the Figure 1.2, are good thermal insulators because their feather filling traps a lot of air. Another example of a thermal insulator is pictured in the Figure 1.3. The picture shows fluffy pink insulation inside the attic of a home. Like the down filling in a snowsuit, the insulation traps a lot of air. The insulation helps to prevent the transfer of thermal energy into the house on hot days and out of the house on cold days. Other materials that are thermal insulators include plastic and wood. Thats why pot handles and cooking utensils are often made of these materials. Notice that the outside of the toaster pictured in the opening image is made of plastic. The plastic casing helps prevent the transfer of thermal energy from the heating element inside to the outer surface of the toaster where it could cause burns. Q: Thermal insulators have many practical uses besides the uses mentioned above. Can you think of others? A: Thermal insulators are often used to keep food or drinks hot or cold. For example, Styrofoam coolers and thermos containers are used for these purposes. "
Warmer air rises because it is less dense than cooler air.,(A) true (B) false,A,"Why does warm air rise (Figure 1.1)? Gas molecules are able to move freely, and if they are uncontained, as they are in the atmosphere, they can take up more or less space. When gas molecules are cool, they are sluggish and do not take up as much space. With the same number of molecules in less space, both air density and air pressure are higher. When gas molecules are warm, they move vigorously and take up more space. Air density and air pressure are lower. Warmer, lighter air is more buoyant than the cooler air above it, so it rises. The cooler air then sinks down, because it is denser than the air beneath it. This is convection, which was described in the chapter Plate Tectonics. "
All objects radiate thermal energy.,(A) true (B) false,A,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
Convection currents carry thermal energy from the sun to Earth.,(A) true (B) false,B,"Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earths surface, through water in the oceans, and through air in the atmosphere. Convection currents in the atmosphere create winds. You can see one way this happens in the Figure 1.2. The land heats up and cools off faster than the water because it has lower specific heat. Therefore, the land gets warmer during the day and cooler at night than the water does. During the day, warm air rises above the land and cool air from the water moves in to take its place. During the night, the opposite happens. Warm air rises above the water and cool air from the land moves out to take its place. Q: During the day, in which direction is thermal energy of the air transferred? In which direction is it transferred during the night? A: During the day, thermal energy is transferred from the air over the land to the air over the water. During the night, thermal energy is transferred in the opposite direction. "
Fluid particles with more energy have greater density.,(A) true (B) false,B,"Density, or the amount of mass in a given volume, is also related to the ability of an object to float. Thats because density affects weight. A given volume of a denser substance is heavier than the same volume of a less dense substance. For example, ice is less dense than liquid water. This explains why the giant ice berg in the Figure 1.3 is floating in the ocean. Q: Can you think of more examples of substances that float in a fluid because they are low in density? A: Oil is less dense than water, so oil from a spill floats on ocean water. Helium is less dense than air, so balloons filled with helium float in air. "
Metals are excellent thermal conductors because they have freely moving electrons.,(A) true (B) false,A,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
A land breeze is an example of a convection current.,(A) true (B) false,A,Ocean water is slower to warm up and cool down than land. So the sea surface is cooler than the land in the daytime. It is also cooler than the land in the summer. The opposite is also true. The water stays warmer than the land during the night and the winter. These differences in heating cause local winds known as land and sea breezes. Land and sea breezes are illustrated in Figure 15.20. A sea breeze blows from sea to land during the day or in summer. Thats when air over the land is warmer than air over the water. The warm air rises. Cool air from over the water flows in to take its place. A land breeze blows from land to sea during the night or in winter. Thats when air over the water is warmer than air over the land. The warm air rises. Cool air from the land flows out to take its place. 
Thermal energy is transferred from a space heater to a person in front of it by conduction.,(A) true (B) false,B,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
The function of a thermostat is to transfer thermal energy.,(A) true (B) false,B,"A refrigerator is an example of a cooling system. Another example is an air conditioner. The purpose of any cooling system is to transfer thermal energy in order to keep things cool. A refrigerator, for example, transfers thermal energy from the cool air inside the refrigerator to the warm air in the kitchen. If youve ever noticed how warm the back of a running refrigerator gets, then you know that it releases a lot of thermal energy into the room. Q: Thermal energy always moves from a warmer area to a cooler area. How can thermal energy move from the cooler air inside a refrigerator to the warmer air in a room? A: The answer is work. "
What happens to hot water as it moves through a homes hot-water heating system?,(A) It transfers thermal energy to the rooms of the house (B) It cools down and returns to the boiler (C) It turns to steam (D) which runs the fan (E) d two of the above,D,"A hot-water heating system produces thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a simple diagram of this type of heating system in the Figure 1.1. Water is heated in a boiler that burns a fuel such as natural gas or heating oil. The boiler converts the chemical energy stored in the fuel to thermal energy. The heated water is pumped from the boiler through pipes and radiators throughout the house. There is usually a radiator in each room. The radiators get warm when the hot water flows through them. The warm radiators radiate thermal energy to the air around them. The warm air then circulates throughout the rooms in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. Q: Look closely at the hot-water heating system in the Figure 1.1. The radiator is a coiled pipe through which hot water flows. What happens to the water as it flows through the radiator? Why is each radiator connected to two pipes? Why cant water flow directly from one radiator to another through a single pipe? A: The radiator is where most of the energy transfer occurs. Water passes through such a great length of pipe in the radiator that it transfers a lot of thermal energy to the radiator. As the water transfers thermal energy, it gets cooler. The cool water flows into a return pipe rather than going directly to another radiator because the cool water no longer has enough thermal energy to heat a room. "
The water in a hot-water heating system is heated by a furnace.,(A) true (B) false,B,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
"In a warm-air heating system, cold air in each room",(A) enters an intake vent near the ceiling (B) blows out of a vent and across the room (C) leaves the house through the chimney (D) transfers thermal energy to the furnace,A,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
"In a warm-air heating system, pipes carry thermal energy throughout the house.",(A) true (B) false,B,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
What happens when the refrigerant of a cooling system absorbs thermal energy?,(A) It melts (B) It thaws (C) It condenses (D) It evaporates,D,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
How are internal and external combustion engines similar?,(A) Both burn fuel in a cylinder (B) Both produce thermal energy (C) Both have a piston that moves in a cylinder (D) two of the above,D,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work. There are two types of combustion engines: external and internal. A steam engine is an external combustion engine. 
Thermal energy from inside a refrigerator changes the refrigerant to a gas.,(A) true (B) false,A,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
A combustion engine burns fuel to produce thermal energy.,(A) true (B) false,A,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the energy to do work. Two basic types of combustion engines are external and internal combustion engines. 
"In a functioning combustion engine, the piston has",(A) kinetic energy (B) electrical energy (C) chemical energy (D) thermal energy,A,"An internal combustion engine (see Figure 18.16) burns fuel internally, or inside the engine. This type of engine is found in most cars and other motor vehicles. It works in these steps, which keep repeating: 1. A mixture of fuel and air is pulled into a cylinder through a valve, which then closes. 2. The piston is pushed upward, compressing the fuel-air mixture in the closed cylinder. The mixture is now under a lot of pressure and very warm. 3. A spark from a spark plug is used to ignite the fuel-air mixture, causing it to burn explosively within the confined space of the closed cylinder. 4. The pressure of the hot gases from combustion forces the piston downward. 5. When the piston moves up again, it forces the exhaust gases of combustion out of the cylinder though another valve. Then the process repeats. In a car, the piston is connected by the piston rod to the crankshaft. The crankshaft rotates when the piston moves up and down. The kinetic energy of the moving crankshaft is used to turn the driveshaft, which causes the wheels of the car to turn. Most cars have at least four cylinders connected to the crankshaft. Their pistons move up and down in sequence, one after the other. You can watch animations of internal combustion engines in action at these URLs: http://auto.howstuffworks.com/engine1.htm "
"In any combustion engine, the engine does the work of moving a piston.",(A) true (B) false,A,"An internal combustion engine (see Figure 18.16) burns fuel internally, or inside the engine. This type of engine is found in most cars and other motor vehicles. It works in these steps, which keep repeating: 1. A mixture of fuel and air is pulled into a cylinder through a valve, which then closes. 2. The piston is pushed upward, compressing the fuel-air mixture in the closed cylinder. The mixture is now under a lot of pressure and very warm. 3. A spark from a spark plug is used to ignite the fuel-air mixture, causing it to burn explosively within the confined space of the closed cylinder. 4. The pressure of the hot gases from combustion forces the piston downward. 5. When the piston moves up again, it forces the exhaust gases of combustion out of the cylinder though another valve. Then the process repeats. In a car, the piston is connected by the piston rod to the crankshaft. The crankshaft rotates when the piston moves up and down. The kinetic energy of the moving crankshaft is used to turn the driveshaft, which causes the wheels of the car to turn. Most cars have at least four cylinders connected to the crankshaft. Their pistons move up and down in sequence, one after the other. You can watch animations of internal combustion engines in action at these URLs: http://auto.howstuffworks.com/engine1.htm "
"In a warm-air heating system, warm-air vents are always placed near the ceiling.",(A) true (B) false,B,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
An air conditioner is an example of a cooling system.,(A) true (B) false,A,"A refrigerator is an example of a cooling system. Another example is an air conditioner. The purpose of any cooling system is to transfer thermal energy in order to keep things cool. A refrigerator, for example, transfers thermal energy from the cool air inside the refrigerator to the warm air in the kitchen. If youve ever noticed how warm the back of a running refrigerator gets, then you know that it releases a lot of thermal energy into the room. Q: Thermal energy always moves from a warmer area to a cooler area. How can thermal energy move from the cooler air inside a refrigerator to the warmer air in a room? A: The answer is work. "
Refrigerant changes to a liquid in the condenser of a refrigerator.,(A) true (B) false,A,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
Steam ships have internal combustion engines.,(A) true (B) false,B,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work. There are two types of combustion engines: external and internal. A steam engine is an external combustion engine. 
The purpose of a radiator in a heating system is to produce thermal energy.,(A) true (B) false,B,"A hot-water heating system produces thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a simple diagram of this type of heating system in the Figure 1.1. Water is heated in a boiler that burns a fuel such as natural gas or heating oil. The boiler converts the chemical energy stored in the fuel to thermal energy. The heated water is pumped from the boiler through pipes and radiators throughout the house. There is usually a radiator in each room. The radiators get warm when the hot water flows through them. The warm radiators radiate thermal energy to the air around them. The warm air then circulates throughout the rooms in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. Q: Look closely at the hot-water heating system in the Figure 1.1. The radiator is a coiled pipe through which hot water flows. What happens to the water as it flows through the radiator? Why is each radiator connected to two pipes? Why cant water flow directly from one radiator to another through a single pipe? A: The radiator is where most of the energy transfer occurs. Water passes through such a great length of pipe in the radiator that it transfers a lot of thermal energy to the radiator. As the water transfers thermal energy, it gets cooler. The cool water flows into a return pipe rather than going directly to another radiator because the cool water no longer has enough thermal energy to heat a room. "
substance that absorbs and releases thermal energy in a cooling system,(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,C,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
Warm air moves through the ducts of heating system because of gravity.,(A) true (B) false,B,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
device in a heating system that controls the furnace or boiler,(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,G,"A thermostat, like the one seen in the Figure 1.3, is an important part of any home heating system. It is like the brain of the entire system. It constantly monitors the temperature in the home and tells the boiler or furnace when to turn on or off. The thermostat is set at a selected temperature, say 71  F. When the temperature in the home starts to fall below this point, the thermostat triggers the boiler or furnace to start running. When the temperature starts to rise above this point, the thermostat triggers the boiler or furnace to stop running. In this way, the thermostat maintains the homes temperature at the set point. "
complex machine that produces thermal energy outside the machine and uses the thermal energy to do,(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,E,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work. There are two types of combustion engines: external and internal. A steam engine is an external combustion engine. 
The transfer of thermal energy can be used to keep things cool.,(A) true (B) false,A,"Its easy to see how thermal energy can be used to keep things warm. But did you know that thermal energy can also be used to keep things cool? Cooling systems such as air conditioners and refrigerators transfer thermal energy in order to keep homes and cars cool or to keep food cold. In a refrigerator, for example, thermal energy is transferred from the cool air inside the refrigerator to the warmer air in the kitchen. You read in this chapters ""Transfer of Thermal Energy"" lesson that thermal energy always moves from a warmer area to a cooler area, so how can it move from the cooler refrigerator to the warmer room? The answer is work. The refrigerator does work to transfer thermal energy in this way. Doing this work takes energy, which is usually provided by electricity. Figure 18.14 explains how a refrigerator does its work. For an animated demonstration of how a refrigerator works, go to this URL:  The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance, such as FreonTM, that has a low boiling point and changes between liquid and gaseous states as it passes through the cooling system. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it releases thermal energy to the warm air outside the refrigerator and changes back to a liquid. "
"heating system that includes a boiler, pipes, and radiators",(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,F,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
Thermal energy naturally moves from a warmer area to a cooler area.,(A) true (B) false,A,"A refrigerator is an example of a cooling system. Another example is an air conditioner. The purpose of any cooling system is to transfer thermal energy in order to keep things cool. A refrigerator, for example, transfers thermal energy from the cool air inside the refrigerator to the warm air in the kitchen. If youve ever noticed how warm the back of a running refrigerator gets, then you know that it releases a lot of thermal energy into the room. Q: Thermal energy always moves from a warmer area to a cooler area. How can thermal energy move from the cooler air inside a refrigerator to the warmer air in a room? A: The answer is work. "
The piston of a combustion engine moves because the crankshaft turns.,(A) true (B) false,B,"In a car, the piston in the engine is connected by the piston rod to the crankshaft. The crankshaft rotates when the piston moves up and down. The crankshaft, in turn, is connected to the driveshaft. When the crankshaft rotates, so does the driveshaft. The rotating driveshaft turns the wheels of the car. "
complex machine that produces thermal energy inside the machine and uses the thermal energy to do work,(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,A,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the thermal energy to do work. There are two types of combustion engines: external and internal. A steam engine is an external combustion engine. 
refrigerator or air conditioner,(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,B,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
"heating system that includes a furnace, ducts, and vents",(A) internal combustion engine (B) cooling system (C) refrigerant (D) warm-air heating system (E) external combustion engine (F) hot-water heating system (G) thermostat,D,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
Types of home heating systems include,(A) warm-air heating systems (B) hot-water heating systems (C) solar heating systems (D) all of the above,D,"Modern home heating systems keep us comfortable in cold weather. We may even depend on them for our survival. But we often take them for granted. Two common types of home heating systems are hot-water and warm-air heating systems. Both types are described below. Thermal energy is the total energy of moving particles of matter. The transfer of thermal energy is called heat. Therefore, a heating system is a system for the transfer of thermal energy. Regardless of the type of heating system in a home, the basic function is the same: to produce thermal energy and transfer it to air throughout the house. "
How is thermal energy transferred in a refrigerator?,(A) from the warm kitchen to the cool refrigerator (B) from the cool refrigerator to the warm kitchen (C) from the cool refrigerator to the cold outdoors (D) two of the above,B,"Its easy to see how thermal energy can be used to keep things warm. But did you know that thermal energy can also be used to keep things cool? Cooling systems such as air conditioners and refrigerators transfer thermal energy in order to keep homes and cars cool or to keep food cold. In a refrigerator, for example, thermal energy is transferred from the cool air inside the refrigerator to the warmer air in the kitchen. You read in this chapters ""Transfer of Thermal Energy"" lesson that thermal energy always moves from a warmer area to a cooler area, so how can it move from the cooler refrigerator to the warmer room? The answer is work. The refrigerator does work to transfer thermal energy in this way. Doing this work takes energy, which is usually provided by electricity. Figure 18.14 explains how a refrigerator does its work. For an animated demonstration of how a refrigerator works, go to this URL:  The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance, such as FreonTM, that has a low boiling point and changes between liquid and gaseous states as it passes through the cooling system. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it releases thermal energy to the warm air outside the refrigerator and changes back to a liquid. "
Why must a cooling system do work to keep things cool?,(A) It transfers thermal energy from a cooler to a warmer place (B) It takes energy to reverse the normal direction of heat flow (C) It takes energy to maintain the normal direction of heat flow (D) two of the above,D,"A refrigerator is an example of a cooling system. Another example is an air conditioner. The purpose of any cooling system is to transfer thermal energy in order to keep things cool. A refrigerator, for example, transfers thermal energy from the cool air inside the refrigerator to the warm air in the kitchen. If youve ever noticed how warm the back of a running refrigerator gets, then you know that it releases a lot of thermal energy into the room. Q: Thermal energy always moves from a warmer area to a cooler area. How can thermal energy move from the cooler air inside a refrigerator to the warmer air in a room? A: The answer is work. "
What happens to the refrigerant as it passes through a cooling system?,(A) It freezes and lowers the temperature of the system (B) It changes between liquid and gaseous states (C) It releases thermal energy into the refrigerator (D) It keeps evaporating and has to be replaced,B,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
"In an external combustion engine, thermal energy is used directly to",(A) move the piston back and forth (B) move the piston up and down (C) turn water into steam (D) all of the above,C,"What can you do to avoid infectious diseases? Eating well and getting plenty of sleep are a good start. These habits will help keep your immune system healthy. With a healthy immune system, you will be able to fight off many pathogens. Vaccines are available for some infectious diseases. For example, there are vaccines to prevent measles, mumps, whooping cough, and chicken pox. These vaccines are recommended for infants and young children. You can also take the following steps to avoid picking up pathogens or spreading them to others. Watch this video for additional information on preventing the spread of infectious diseases:  MEDIA Click image to the left or use the URL below. URL:  Wash your hands often with soap and water. Spend at least 20 seconds scrubbing with soap. See Figure 21.3 for effective hand washing tips. Avoid touching your eyes, nose, or mouth with unwashed hands. Avoid close contact with people who are sick. This includes kissing, hugging, shaking hands, and sharing cups or eating utensils. Cover your coughs and sneezes with a tissue or shirt sleeve, not your hands. Disinfect frequently touched surfaces, such as keyboards and doorknobs, especially if someone is sick. Stay home when you are sick. The best way to prevent diseases spread by vectors is to avoid contact with the vectors. For example, you can wear long sleeves and long pants to avoid tick and mosquito bites. Using insect repellent can also reduce your risk of insect bites. "
What happens first in an internal combustion engine?,(A) Exhaust gases exit the cylinder (B) The piston moves up or down (C) A fuel-air mixture enters the cylinder (D) The piston rod turns the crankshaft,C,"An internal combustion engine (see Figure 18.16) burns fuel internally, or inside the engine. This type of engine is found in most cars and other motor vehicles. It works in these steps, which keep repeating: 1. A mixture of fuel and air is pulled into a cylinder through a valve, which then closes. 2. The piston is pushed upward, compressing the fuel-air mixture in the closed cylinder. The mixture is now under a lot of pressure and very warm. 3. A spark from a spark plug is used to ignite the fuel-air mixture, causing it to burn explosively within the confined space of the closed cylinder. 4. The pressure of the hot gases from combustion forces the piston downward. 5. When the piston moves up again, it forces the exhaust gases of combustion out of the cylinder though another valve. Then the process repeats. In a car, the piston is connected by the piston rod to the crankshaft. The crankshaft rotates when the piston moves up and down. The kinetic energy of the moving crankshaft is used to turn the driveshaft, which causes the wheels of the car to turn. Most cars have at least four cylinders connected to the crankshaft. Their pistons move up and down in sequence, one after the other. You can watch animations of internal combustion engines in action at these URLs: http://auto.howstuffworks.com/engine1.htm "
Thermal energy from a radiator travels throughout the air in a room by,(A) conduction (B) convection (C) radiation (D) all of the above,D,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
You can start a surface wave by,(A) pushing and pulling on a spring (B) shaking a rope up and down (C) dropping a pebble in a pond (D) all of the above,C,"A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think causes ocean waves? A: Most ocean waves are caused by wind blowing across the water. Moving air molecules transfer some of their energy to molecules of ocean water. The energy travels across the surface of the water in waves. The stronger the winds are blowing, the larger the waves are and the more energy they have. "
What is required for a mechanical wave to occur?,(A) a disturbance in matter (B) a source of energy (C) particles of matter (D) all of the above,D,"A mechanical wave is a disturbance in matter that transfers energy from place to place. A mechanical wave starts when matter is disturbed. An example of a mechanical wave is pictured in Figure 19.1. A drop of water falls into a pond. This disturbs the water in the pond. What happens next? The disturbance travels outward from the drop in all directions. This is the wave. A source of energy is needed to start a mechanical wave. In this case, the energy comes from the falling drop of water. "
The parts of a longitudinal wave where particles of matter are spread farthest apart are called,(A) crests (B) vibrations (C) rarefactions (D) compressions,C,"Notice in the Figure 1.1 that the coils of the spring first crowd closer together and then spread farther apart as the wave passes through them. Places where particles of a medium crowd closer together are called compressions, and places where the particles spread farther apart are called rarefactions. The more energy the wave has, the closer together the particles are in compressions and the farther apart they are in rarefactions. "
The lowest parts of a transverse wave is are known as,(A) valleys (B) troughs (C) bottoms (D) media,B,"A transverse wave is characterized by the high and low points reached by particles of the medium as the wave passes through. The high points are called crests, and the low points are called troughs. You can see both in the Figure below. "
What is an S wave?,(A) any transverse wave (B) a type of longitudinal wave (C) a wave generated by an earthquake (D) two of the above,C,Transverse waves called S waves occur during earthquakes. The disturbance that causes an earthquake sends transverse waves through underground rocks in all directions away from the disturbance. S waves may travel for hundreds of miles. An S wave is modeled in the Figure 1.3. 
A mechanical wave starts with a disturbance in matter.,(A) true (B) false,A,"A mechanical wave is a disturbance in matter that transfers energy from place to place. A mechanical wave starts when matter is disturbed. An example of a mechanical wave is pictured in Figure 19.1. A drop of water falls into a pond. This disturbs the water in the pond. What happens next? The disturbance travels outward from the drop in all directions. This is the wave. A source of energy is needed to start a mechanical wave. In this case, the energy comes from the falling drop of water. "
Particles of matter actually travel along with a mechanical wave.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
Transverse waves travel only through solid matter.,(A) true (B) false,B,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
Ocean waves travel deep below the surface of the water.,(A) true (B) false,B,"A surface wave is a wave that travels along the surface of a medium. It combines a transverse wave and a longitudinal wave. Ocean waves are surface waves. They travel on the surface of the water between the ocean and the air. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. This is illustrated in Figure 19.8 and at the URL below. MEDIA Click image to the left or use the URL below. URL:  In deep water, particles of water just move in circles. They dont actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. They start to drag on the bottom, creating friction (see Figure 19.9). The friction slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. This causes the waves to get steeper until they topple over and crash on the shore. The crashing waves carry water onto the shore as surf. "
Earthquakes cause longitudinal waves.,(A) true (B) false,A,"Earthquakes cause longitudinal waves as well as transverse waves. The disturbance that causes an earthquake sends longitudinal waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called primary, or P, waves. They are illustrated in Figure 19.7. "
The medium of a mechanical wave must be a solid or liquid.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
"In a surface wave, particles of the medium move only up and down.",(A) true (B) false,B,"A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. You can see how the particles move in the Figure 1.1. Click image to the left or use the URL below. URL: "
Ocean waves crash on shore when the bottoms of the waves slow down due to friction.,(A) true (B) false,A,"Figure 14.10 shows what happens to waves near shore. As waves move into shallow water, they start to touch the bottom. The base of the waves drag and slow. Soon the waves slow down and pile up. They get steeper and unstable as the top moves faster than the base. When they reach the shore, the waves topple over and break. "
"In a surface wave, particles of matter move in a circular motion.",(A) true (B) false,A,"A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. You can see how the particles move in the Figure 1.1. Click image to the left or use the URL below. URL: "
All waves transfer energy from one place to another.,(A) true (B) false,A,"All waves are the way energy travels through matter. Ocean waves are energy traveling through water. They form when wind blows over the surface of the ocean. Wind energy is transferred to the sea surface. Then, the energy is carried through the water by the waves. Figure 10.11 shows ocean waves crashing against rocks on a shore. They pound away at the rocks and anything else they strike. Three factors determine the size of ocean waves: 1. The speed of the wind. 2. The length of time the wind blows. 3. The distance the wind blows. The faster, longer, and farther the wind blows, the bigger the waves are. Bigger waves have more energy. "
A primary (P) wave is a longitudinal wave.,(A) true (B) false,A,"Earthquakes cause longitudinal waves as well as transverse waves. The disturbance that causes an earthquake sends longitudinal waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called primary, or P, waves. They are illustrated in Figure 19.7. "
All waves must travel through matter.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
All mechanical waves are either transverse or longitudinal waves.,(A) true (B) false,B,"There are three types of mechanical waves: transverse, longitudinal, and surface waves. They differ in how particles of the medium move. You can see this in the Figure 1.1. In a transverse wave, particles of the medium vibrate up and down perpendicular to the direction of the wave. In a longitudinal wave, particles of the medium vibrate back and forth parallel to the direction of the wave. In a surface wave, particles of the medium vibrate both up and down and back and forth, so they end up moving in a circle. Q: How do you think surface waves are related to transverse and longitudinal waves? A: A surface wave is combination of a transverse wave and a longitudinal wave. "
Some waves do not require a medium.,(A) true (B) false,A,"Unlike a mechanical transverse wave, which requires a medium, an electromagnetic transverse wave can travel through space without a medium. Waves traveling through a medium lose some energy to the medium. However, when an electromagnetic wave travels through space, no energy is lost, so the wave doesnt get weaker as it travels. However, the energy is ""diluted"" as it spreads out over an ever-larger area as it travels away from the source. This is similar to the way a sound wave spreads out and becomes less intense farther from the sound source. "
A source of energy is needed to start a mechanical wave.,(A) true (B) false,A,"A mechanical wave is a disturbance in matter that transfers energy from place to place. A mechanical wave starts when matter is disturbed. An example of a mechanical wave is pictured in Figure 19.1. A drop of water falls into a pond. This disturbs the water in the pond. What happens next? The disturbance travels outward from the drop in all directions. This is the wave. A source of energy is needed to start a mechanical wave. In this case, the energy comes from the falling drop of water. "
disturbance in matter that transfers energy from place to place,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,C,"A mechanical wave is a disturbance in matter that transfers energy from place to place. A mechanical wave starts when matter is disturbed. An example of a mechanical wave is pictured in Figure 19.1. A drop of water falls into a pond. This disturbs the water in the pond. What happens next? The disturbance travels outward from the drop in all directions. This is the wave. A source of energy is needed to start a mechanical wave. In this case, the energy comes from the falling drop of water. "
part of a longitudinal wave where particles of the medium are spread farthest apart,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,F,"A longitudinal wave can be characterized by the compressions and rarefactions of the medium. This is illustrated in Figure 19.6. Compressions are the places where the coils are crowded together, and rarefactions are the places where the coils are spread apart. "
wave in which particles of the medium vibrate at right angles to the direction that the wave travels,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,G,"A transverse wave is a wave in which particles of the medium vibrate at right angles, or perpendicular, to the direction that the wave travels. Another example of a transverse wave is the wave that passes through a rope with you shake one end of the rope up and down, as in the Figure 1.1. The direction of the wave is down the length of the rope away from the hand. The rope itself moves up and down as the wave passes through it. Click image to the left or use the URL below. URL:  Q: When a guitar string is plucked, in what direction does the wave travel? In what directions does the string vibrate? A: The wave travels down the string to the end. The string vibrates up and down at right angles to the direction of the wave. "
combined transverse and longitudinal wave,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,E,"A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. You can see how the particles move in the Figure 1.1. Click image to the left or use the URL below. URL: "
part of a transverse wave where particles of the medium are lowest,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,B,"A transverse wave is characterized by the high and low points reached by particles of the medium as the wave passes through. The high points are called crests, and the low points are called troughs. You can see both in the Figure below. "
wave in which particles of the medium vibrate in the same direction that the wave travels,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,A,"A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. You can see how the particles move in the Figure 1.1. Click image to the left or use the URL below. URL: "
matter through which a mechanical wave travels,(A) longitudinal wave (B) trough (C) mechanical wave (D) medium (E) surface wave (F) rarefaction (G) transverse wave,D,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
Types of mechanical waves include,(A) longitudinal waves (B) transverse waves (C) surface waves (D) all of the above,D,"There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. "
The medium of a mechanical wave can be a,(A) gas (B) solid (C) liquid (D) any of the above,D,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
The crests of a transverse wave are like the,(A) crests of a primary wave (B) troughs of a longitudinal wave (C) rarefactions of a secondary wave (D) compressions of a longitudinal wave,D,"A transverse wave is characterized by the high and low points reached by particles of the medium as the wave passes through. The high points are called crests, and the low points are called troughs. You can see both in the Figure below. "
Examples of mechanical waves include all of the following except,(A) ocean waves (B) sound waves (C) waves in a rope (D) electromagnetic waves,D,"There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. "
Waves that an earthquake sends through rocks underground include,(A) tsunami waves (B) transverse waves (C) longitudinal waves (D) two of the above,D,"Earthquakes cause longitudinal waves as well as transverse waves. The disturbance that causes an earthquake sends longitudinal waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called primary, or P, waves. They are illustrated in Figure 19.7. "
Which of the following statements about ocean waves is true?,(A) They travel on the surface of the water (B) They travel deep underwater (C) They are secondary waves (D) They are primary waves,A,"All waves are the way energy travels through matter. Ocean waves are energy traveling through water. They form when wind blows over the surface of the ocean. Wind energy is transferred to the sea surface. Then, the energy is carried through the water by the waves. Figure 10.11 shows ocean waves crashing against rocks on a shore. They pound away at the rocks and anything else they strike. Three factors determine the size of ocean waves: 1. The speed of the wind. 2. The length of time the wind blows. 3. The distance the wind blows. The faster, longer, and farther the wind blows, the bigger the waves are. Bigger waves have more energy. "
You generate a longitudinal wave when you,(A) shake a spring up and down (B) shake a rope up and down (C) push and pull a spring (D) two of the above,C,"A longitudinal wave is a type of mechanical wave. A mechanical wave is a wave that travels through matter, called the medium. In a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. You can see this in the Figure 1.1. The persons hand pushes and pulls on one end of the spring. The energy of this disturbance passes through the coils of the spring to the other end. Click image to the left or use the URL below. URL: "
"The less compressed particles of matter become in a longitudinal wave, the greater the waves amplitude.",(A) true (B) false,B,"Wave amplitude is the maximum distance the particles of a medium move from their resting position when a wave passes through. The resting position is where the particles would be in the absence of a wave. In a transverse wave, wave amplitude is the height of each crest above the resting position. The higher the crests are, the greater the amplitude. In a longitudinal wave, amplitude is a measure of how compressed particles of the medium become when the wave passes through. The closer together the particles are, the greater the amplitude. What determines a waves amplitude? It depends on the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles, like those in Figure 19.1. The ripples are low-amplitude waves. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves. "
"In a longitudinal wave, amplitude is a measure of",(A) how many waves pass a fixed point each second (B) how close together particles of the medium become (C) how quickly the wave travels a given distance (D) how far apart adjacent compressions are,B,The height of a wave is its amplitude. Another measure of wave size is wavelength. Both wave amplitude and wave- length are described in detail below. Figure 19.11 shows these wave measures for both transverse and longitudinal waves. You can also simulate waves with different amplitudes and wavelengths by doing the interactive animation at this URL: http://sci-culture.com/advancedpoll/GCSE/sine%20wave%20simulator.html . 
The distance between two adjacent compressions of a longitudinal wave is its wavelength.,(A) true (B) false,A,"A longitudinal wave can be characterized by the compressions and rarefactions of the medium. This is illustrated in Figure 19.6. Compressions are the places where the coils are crowded together, and rarefactions are the places where the coils are spread apart. "
"If two waves have the same amplitude, the wave with more energy is the wave with the",(A) shorter wavelength (B) lower frequency (C) denser medium (D) slower speed,A,A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low- amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves and have a great deal of energy. 
The frequency of a wave is the same as the frequency of the vibrations that caused the wave.,(A) true (B) false,A,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
"If two waves have the same speed, the wave with a higher frequency must have a",(A) shorter wavelength (B) longer wavelength (C) greater amplitude (D) two of the above,A,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
Wave speed is a product of,(A) wavelength and frequency (B) wavelength and amplitude (C) frequency and amplitude (D) none of the above,A,"Wave speed is the distance a wave travels in a given amount of time, such as the number of meters it travels per second. Wave speed (and speed in general) can be represented by the equation: Speed = Distance Time "
Wave speed measures the same thing as wave frequency.,(A) true (B) false,B,"Wave speed is related to both wavelength and wave frequency. Wavelength is the distance between two correspond- ing points on adjacent waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. This equation shows how the three factors are related: Speed = Wavelength x Wave Frequency In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed. Q: If you increase the wavelength of a wave, does the speed of the wave increase as well? A: Increasing the wavelength of a wave doesnt change its speed. Thats because when wavelength increases, wave frequency decreases. As a result, the product of wavelength and wave frequency is still the same speed. Click image to the left or use the URL below. URL: "
Wavelength equals wave speed multiplied by wave frequency.,(A) true (B) false,B,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
What is the frequency of a wave that has a wavelength of 2 m and a speed of 2 m/s?,(A) 4 Hz (B) 2 Hz (C) 1 Hz (D) 12 Hz,C,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
The resting position of particles in a longitudinal wave is where the particles are most spread out.,(A) true (B) false,B,"Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. The resting position of a particle of the medium is where the particle would be in the absence of a wave. The Figure 1.1 show the amplitudes of two different types of waves: transverse and longitudinal waves. In a transverse wave, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave. In a longitudinal wave, particles of the medium move back and forth in the same direction as the wave. Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. The closer together the particles are, the greater the amplitude of the wave. Q: What do you think determines a waves amplitude? A: Wave amplitude is determined by the energy of the disturbance that causes the wave. "
A wave caused by a disturbance with greater energy has greater amplitude.,(A) true (B) false,A,A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low- amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves and have a great deal of energy. 
"If you know the speed and wavelength of a wave, you can calculate its frequency.",(A) true (B) false,A,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
Waves generally travel most slowly in gases.,(A) true (B) false,A,"The speed of most waves depends on the medium through which they are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle. "
A wave with a higher frequency always has a greater speed than a wave with a lower frequency.,(A) true (B) false,B,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
One measure of wave size is wave frequency.,(A) true (B) false,B,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
Measures of wave size include,(A) wavelength (B) wave amplitude (C) wave frequency (D) two of the above,D,The height of a wave is its amplitude. Another measure of wave size is wavelength. Both wave amplitude and wave- length are described in detail below. Figure 19.11 shows these wave measures for both transverse and longitudinal waves. You can also simulate waves with different amplitudes and wavelengths by doing the interactive animation at this URL: http://sci-culture.com/advancedpoll/GCSE/sine%20wave%20simulator.html . 
The resting position of a transverse wave is called a trough.,(A) true (B) false,B,"A transverse wave is characterized by the high and low points reached by particles of the medium as the wave passes through. The high points are called crests, and the low points are called troughs. You can see both in the Figure below. "
The amplitude of a transverse wave is the distance between,(A) two adjacent crests (B) two adjacent troughs (C) a crest and a trough (D) a crest and the resting position,D,"Wave amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. The resting position of a particle of the medium is where the particle would be in the absence of a wave. The Figure 1.1 show the amplitudes of two different types of waves: transverse and longitudinal waves. In a transverse wave, particles of the medium move up and down at right angles to the direction of the wave. Wave amplitude of a transverse wave is the difference in height between the crest and the resting position. The crest is the highest point particles of the medium reach. The higher the crests are, the greater the amplitude of the wave. In a longitudinal wave, particles of the medium move back and forth in the same direction as the wave. Wave amplitude of a longitudinal wave is the distance between particles of the medium where it is compressed by the wave. The closer together the particles are, the greater the amplitude of the wave. Q: What do you think determines a waves amplitude? A: Wave amplitude is determined by the energy of the disturbance that causes the wave. "
What is the speed of a wave that has a wavelength of 0.5 meters and a frequency of 2 waves per second?,(A) 14 m/s (B) 1 m/s (C) 4 m/s (D) 10 m/s,B,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
"If you know only a waves amplitude and wavelength, you can calculate its speed.",(A) true (B) false,B,"The equation for wave speed can be used to calculate the speed of a wave when both wavelength and wave frequency are known. Consider an ocean wave with a wavelength of 3 meters and a frequency of 1 hertz. The speed of the wave is: Speed = 3 m x 1 wave/s = 3 m/s Q: Kim made a wave in a spring by pushing and pulling on one end. The wavelength is 0.1 m, and the wave frequency is 2 hertz. What is the speed of the wave? A: Substitute these values into the equation for speed: Speed = 0.1 m x 2 waves/s = 0.2 m/s "
Wave amplitude depends on,(A) wavelength (B) wave speed (C) wave energy (D) wave frequency (E) wave energy of the original disturbance,C,"Wave amplitude is the maximum distance the particles of a medium move from their resting position when a wave passes through. The resting position is where the particles would be in the absence of a wave. In a transverse wave, wave amplitude is the height of each crest above the resting position. The higher the crests are, the greater the amplitude. In a longitudinal wave, amplitude is a measure of how compressed particles of the medium become when the wave passes through. The closer together the particles are, the greater the amplitude. What determines a waves amplitude? It depends on the energy of the disturbance that causes the wave. A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles, like those in Figure 19.1. The ripples are low-amplitude waves. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves. "
Wave speed and wavelength have an inverse relationship.,(A) true (B) false,B,"Wave speed is related to both wavelength and wave frequency. Wavelength is the distance between two correspond- ing points on adjacent waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. This equation shows how the three factors are related: Speed = Wavelength x Wave Frequency In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed. Q: If you increase the wavelength of a wave, does the speed of the wave increase as well? A: Increasing the wavelength of a wave doesnt change its speed. Thats because when wavelength increases, wave frequency decreases. As a result, the product of wavelength and wave frequency is still the same speed. Click image to the left or use the URL below. URL: "
A tsunami is an ocean wave with an unusually great amplitude.,(A) true (B) false,A,"Tsunami are deadly ocean waves from the sharp jolt of an undersea earthquake. Less frequently, these waves can be generated by other shocks to the sea, like a meteorite impact. Fortunately, few undersea earthquakes, and even fewer meteorite impacts, generate tsunami. "
"When one wave passes a fixed point every second, the frequency of the waves is",(A) 01 Hz (B) 1 Hz (C) 10 Hz (D) none of the above,B,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
"Assume that a wave has a fixed speed. If the frequency of the wave increases, its wavelength",(A) increases (B) decreases (C) does not change (D) may or may not change,B,"Wave speed is related to both wavelength and wave frequency. Wavelength is the distance between two correspond- ing points on adjacent waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. This equation shows how the three factors are related: Speed = Wavelength x Wave Frequency In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed. Q: If you increase the wavelength of a wave, does the speed of the wave increase as well? A: Increasing the wavelength of a wave doesnt change its speed. Thats because when wavelength increases, wave frequency decreases. As a result, the product of wavelength and wave frequency is still the same speed. Click image to the left or use the URL below. URL: "
The speed of waves depends on their,(A) wavelength (B) frequency (C) medium (D) all of the above,D,"The speed of most waves depends on the medium, or the matter through which the waves are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle through the medium. Click image to the left or use the URL below. URL: "
maximum distance the particles of a medium move from their resting position,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,C,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
number of waves that pass a fixed point in a given amount of time,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,E,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
how far a wave travels in a given amount of time,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,G,"Wave speed is the distance a wave travels in a given amount of time, such as the number of meters it travels per second. Wave speed (and speed in general) can be represented by the equation: Speed = Distance Time "
highest point reached by particles of the medium in a transverse wave,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,F,"A transverse wave is characterized by the high and low points reached by particles of the medium as the wave passes through. The high points are called crests, and the low points are called troughs. You can see both in the Figure below. "
distance between two corresponding points on adjacent waves,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,B,Another important measure of wave size is wavelength. Wavelength is the distance between two corresponding points on adjacent waves (see Figure 19.11). Wavelength can be measured as the distance between two adjacent crests of a transverse wave or two adjacent compressions of a longitudinal wave. It is usually measured in meters. Wavelength is related to the energy of a wave. Short-wavelength waves have more energy than long-wavelength waves of the same amplitude. You can see examples of waves with shorter and longer wavelengths in Figure 19.12. 
location of particles of the medium in the absence of a wave,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,D,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
SI unit for wave frequency,(A) hertz (B) wavelength (C) wave amplitude (D) resting position (E) wave frequency (F) crest (G) wave speed,A,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
An echo occurs because of wave,(A) interference (B) diffraction (C) refraction (D) reflection,D,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
"If a wave strikes a barrier at a 45 angle, what is the angle of reflection?",(A) 180 (B) 120 (C) 90 (D) 45,D,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
Light is refracted when it,(A) strikes a barrier it cannot pass through (B) spreads around an obstacle such as a wall (C) passes from air to water at an angle (D) interferes with other waves,C,"Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent where light travels from water to air. Light travels more quickly in air than in water and changes direction. Scattering occurs when light bumps into tiny particles of matter and spreads out in all directions. In the Figure air, giving the headlights a halo appearance. Q: What might be another example of light scattering? A: When light passes through smoky air, it is scattered by tiny particles of soot. "
What happens when a wave passes around a barrier that is shorter than its wavelength?,(A) The wave has a large angle of incidence (B) The wave spreads out around the barrier (C) The wave is refracted (D) none of the above,B,"Did you ever notice that when youre walking down a street, you can hear sounds around the corners of buildings? Figure 19.18 shows why this happens. As you can see from the figure, sound waves spread out and travel around obstacles. This is called diffraction. It also occurs when waves pass through an opening in an obstacle. All waves may be diffracted, but it is more pronounced in some types of waves than others. For example, sound waves bend around corners much more than light does. Thats why you can hear but not see around corners. For a given type of waves, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. This is illustrated in Figure 19.19. Diffraction is minor if the length of the obstacle or opening is greater than the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength. "
Constructive interference occurs when two waves pass through each other and the,(A) crests of both waves cancel each other out (B) crests of both waves have a smaller amplitude (C) crests of one wave overlap crests of the other wave (D) crests of one wave cancel out troughs of the other wave,C,"Constructive interference occurs when the crests of one wave overlap the crests of the other wave. This is illustrated in Figure 19.20. As the waves pass through each other, the crests combine to produce a wave with greater amplitude. You can see an animation of constructive interference at this URL: http://phys23p.sl.psu.edu/phys_anim/waves/em "
Reflection occurs only with sound waves.,(A) true (B) false,B,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
All reflected waves appear to be standing still.,(A) true (B) false,B,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
The angle of incidence is always greater than the angle of reflection.,(A) true (B) false,B,One thing is true of both regular and diffuse reflection. The angle at which the reflected rays leave the surface is equal to the angle at which the incident rays strike the surface. This is known as the law of reflection. The law is illustrated in the Figure 1.3. 
Reflected waves have the same speed as the original waves before they were reflected.,(A) true (B) false,A,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
Diffraction is more pronounced with sound waves than light waves.,(A) true (B) false,A,"Did you ever notice that when youre walking down a street, you can hear sounds around the corners of buildings? Figure 19.18 shows why this happens. As you can see from the figure, sound waves spread out and travel around obstacles. This is called diffraction. It also occurs when waves pass through an opening in an obstacle. All waves may be diffracted, but it is more pronounced in some types of waves than others. For example, sound waves bend around corners much more than light does. Thats why you can hear but not see around corners. For a given type of waves, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. This is illustrated in Figure 19.19. Diffraction is minor if the length of the obstacle or opening is greater than the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength. "
Diffraction occurs because waves travel at different speeds in different media.,(A) true (B) false,B,"Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle. You can see an example of refraction in Figure 19.17. Light bends when it passes from air to water. The bending of the light causes the pencil to appear broken. Why do waves bend as they enter a new medium? Waves usually travel at different speeds in different media. For example, light travels more slowly in water than air. This causes it to refract when it passes from air to water. "
Wave interference occurs whenever waves enter a new medium.,(A) true (B) false,B,"When two or more waves meet, they interact with each other. The interaction of waves with other waves is called wave interference. Wave interference may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. Amplitude is the maximum distance the particles of the medium move from their resting positions when a wave passes through. How amplitude is affected by wave interference depends on the type of interference. Interference can be constructive or destructive. "
Wave interference occurs only when a wave is reflected.,(A) true (B) false,B,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
You can hear sounds around the corner of a building because the sound waves are refracted.,(A) true (B) false,B,"Did you ever notice that when youre walking down a street, you can hear sounds around the corners of buildings? Figure 19.18 shows why this happens. As you can see from the figure, sound waves spread out and travel around obstacles. This is called diffraction. It also occurs when waves pass through an opening in an obstacle. All waves may be diffracted, but it is more pronounced in some types of waves than others. For example, sound waves bend around corners much more than light does. Thats why you can hear but not see around corners. For a given type of waves, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. This is illustrated in Figure 19.19. Diffraction is minor if the length of the obstacle or opening is greater than the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength. "
Light waves refract when they pass from air to water.,(A) true (B) false,A,"Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle. You can see an example of refraction in Figure 19.17. Light bends when it passes from air to water. The bending of the light causes the pencil to appear broken. Why do waves bend as they enter a new medium? Waves usually travel at different speeds in different media. For example, light travels more slowly in water than air. This causes it to refract when it passes from air to water. "
Destructive interference decreases the amplitude of waves.,(A) true (B) false,A,"Destructive interference occurs when the crests of one wave overlap the troughs, or lowest points, of another wave. The Figure 1.2 shows what happens. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. "
A standing wave forms when a wave is refracted.,(A) true (B) false,B,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
Interference occurs only when the crests of one wave overlap with the troughs of another wave.,(A) true (B) false,B,"Destructive interference occurs when the crests of one wave overlap the troughs, or lowest points, of another wave. The Figure 1.2 shows what happens. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. "
A standing wave occurs when a wave is reflected straight back from an obstacle.,(A) true (B) false,A,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
Wave interference always changes the speed of a wave.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
change in direction of waves as they enter a new medium at an angle,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,E,"Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle. You can see an example of refraction in Figure 19.17. Light bends when it passes from air to water. The bending of the light causes the pencil to appear broken. Why do waves bend as they enter a new medium? Waves usually travel at different speeds in different media. For example, light travels more slowly in water than air. This causes it to refract when it passes from air to water. "
bouncing back of waves from a barrier,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,C,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
any interaction of waves with other waves,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,G,"Waves interact not only with matter in the ways described above. Waves also interact with other waves. This is called wave interference. Wave interference may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. How amplitude is affected depends on the type of interference. Interference can be constructive or destructive. "
situation in which crests of one wave overlap crests of another wave,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,D,"Constructive interference occurs when the crests, or highest points, of one wave overlap the crests of the other wave. You can see this in the Figure 1.1. As the waves pass through each other, the crests combine to produce a wave with greater amplitude. "
any interaction of waves with matter,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,B,"Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction. Each type of interaction is described in detail below. For animations of the three types of wave interactions, go to this URL: "
spreading out of waves as they pass around a barrier,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,A,"Did you ever notice that when youre walking down a street, you can hear sounds around the corners of buildings? Figure 19.18 shows why this happens. As you can see from the figure, sound waves spread out and travel around obstacles. This is called diffraction. It also occurs when waves pass through an opening in an obstacle. All waves may be diffracted, but it is more pronounced in some types of waves than others. For example, sound waves bend around corners much more than light does. Thats why you can hear but not see around corners. For a given type of waves, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. This is illustrated in Figure 19.19. Diffraction is minor if the length of the obstacle or opening is greater than the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength. "
situation in which crests of one wave overlap troughs of another wave,(A) diffraction (B) wave interaction (C) reflection (D) constructive interference (E) refraction (F) destructive interference (G) wave interference,F,"Destructive interference occurs when the crests of one wave overlap the troughs, or lowest points, of another wave. The Figure 1.2 shows what happens. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. "
Ways that waves may interact with matter include,(A) diffraction (B) destructive interference (C) constructive interference (D) all of the above,A,"Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction. Each type of interaction is described in detail below. For animations of the three types of wave interactions, go to this URL: "
Reflected waves differ from the original waves before they were reflected in their,(A) speed (B) direction (C) frequency (D) wavelength,B,"An echo is an example of wave reflection. Reflection occurs when waves bounce back from a barrier they cannot pass through. Reflection can happen with any type of waves, not just sound waves. For example, Figure 19.15 shows the reflection of ocean waves off a rocky coast. Light waves can also be reflected. In fact, thats how we see most objects. Light from a light source, such as the sun or a light bulb, shines on the object and some of the light is reflected. When the reflected light enters our eyes, we can see the object. Reflected waves have the same speed and frequency as the original waves before they were reflected. However, the direction of the reflected waves is different. When waves strike an obstacle head on, the reflected waves bounce straight back in the direction they came from. When waves strike an obstacle at any other angle, they bounce back at the same angle but in a different direction. This is illustrated in Figure 19.16. "
Refraction occurs because waves,(A) cannot travel through an obstacle such as a wall (B) travel at different speeds in different media (C) interfere with their reflected waves (D) none of the above,B,"Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle. You can see an example of refraction in Figure 19.17. Light bends when it passes from air to water. The bending of the light causes the pencil to appear broken. Why do waves bend as they enter a new medium? Waves usually travel at different speeds in different media. For example, light travels more slowly in water than air. This causes it to refract when it passes from air to water. "
"If the length of an obstacle is greater than the wavelength of a wave, you would expect to see",(A) no diffraction (B) very little diffraction (C) a lot of diffraction (D) wave interference,B,The wavelength of a wave is related to the waves energy. Short-wavelength waves have more energy than long- wavelength waves of the same amplitude. (Amplitude is a measure of how far particles of the medium move up and down or back and forth when a wave passes through them.) You can see examples of transverse waves with shorter and longer wavelengths in the Figure 1.3. A: Violet light has the greatest energy because it has the shortest wavelength. 
A standing wave is a wave that,(A) is not moving (B) has an upright direction (C) is taller than other waves (D) appears to be standing still,D,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
A standing wave occurs because of a combination of,(A) incidence and reflection (B) refraction and diffraction (C) refraction and interference (D) constructive and destructive interference,D,"When a wave is reflected straight back from an obstacle, the reflected wave interferes with the original wave and creates a standing wave. This is a wave that appears to be standing still. A standing wave occurs because of a combination of constructive and destructive interference between a wave and its reflected wave. You can see animations of standing waves at the URLs below. http://skullsinthestars.com/2008/05/04/classic-science-paper-otto-wieners-experiment-1890/  Its easy to generate a standing wave in a rope by tying one end to a fixed object and moving the other end up and down. When waves reach the fixed object, they are reflected back. The original wave and the reflected wave interfere to produce a standing wave. Try it yourself and see if the wave appears to stand still. "
Which statement about destructive interference is true?,(A) It occurs when waves pass through each other (B) It results in a wave with a higher frequency (C) It occurs when waves interact with matter (D) It always produces a standing wave,A,"Destructive interference occurs when the crests of one wave overlap the troughs of another wave. This is illustrated in Figure 19.21. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with less amplitude. You can see an animation of destructive interference at this URL: http://phys23p.sl.psu.ed "
Through which medium do sounds waves travel most slowly?,(A) air (B) wood (C) glass (D) aluminum,A,"The speed of most waves depends on the medium, or the matter through which the waves are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle through the medium. Click image to the left or use the URL below. URL: "
Assume that sound A has a decibel level of 10 and sound B has a decibel level of 30. How many times louder is sound B than sound A?,(A) 3 (B) 10 (C) 20 (D) 100,D,"The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. Q: How much louder than a 20-decibel whisper is the 60-decibel sound of a vacuum cleaner? A: The vacuum cleaner is 10,000 times louder than the whisper! "
What determines the intensity of sound?,(A) amplitude of sound waves (B) frequency of sound waves (C) distance from the sound source (D) two of the above,D,"The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity results from two factors: the amplitude of the sound waves and how far they have traveled from the source of the sound. Amplitude is a measure of the size of sound waves. It depends on the amount of energy that started the waves. Greater amplitude waves have more energy and greater intensity, so they sound louder. As sound waves travel farther from their source, the more spread out their energy becomes. You can see how this works in the Figure 1.2. As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source. Q: Why can low-amplitude sounds like whispers be heard only over short distances? A: The sound waves already have so little energy that spreading them out over a wider area quickly reduces their intensity below the level of hearing. "
"Compared with a low-pitched sound, a high-pitched sound has sound waves with",(A) greater intensity (B) higher frequency (C) greater amplitude (D) longer wavelength,B,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
Human beings can normally hear sounds with a frequency between about,(A) 10 and 10 (B) 000 Hz (C) b 20 and 20 (D) 000 Hz (E) c 20 and 140 Hz (F) d 10 and 120 Hz,B,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
The speed of sound in air at 20 C is,(A) 343 m/s (B) 1437 m/s (C) 3850 m/s (D) 4540 m/s,A,"The speed of sound also depends on the temperature of the medium. For a given medium, sound has a slower speed at lower temperatures. You can compare the speed of sound in dry air at different temperatures in the following Table 1.2. At a lower temperature, particles of the medium are moving more slowly, so it takes them longer to transfer the energy of the sound waves. Temperature of Air 0 C 20  C 100  C Speed of Sound Waves (m/s) 331 343 386 Q: What do you think the speed of sound might be in dry air at a temperature of -20  C? A: For each 1 degree Celsius that temperature decreases, the speed of sound decreases by 0.6 m/s. So sound travels through dry, -20  C air at a speed of 319 m/s. "
The Doppler effect occurs when the sound source,(A) is moving relative to the listener (B) produces sound waves with a frequency above 10 (C) 000 Hz (D) c starts producing lower frequency sound waves (E) d starts producing greater amplitude sound waves,A,"The Doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. (It can also occur when the sound source is stationary and the listener is moving.) The Figure 1.1 shows how the Doppler effect occurs. The sound waves from the police car siren travel outward in all directions. Because the car is racing forward (to the left), the sound waves get bunched up in front of the car and spread out behind it. Sound waves that are closer together have a higher frequency, and sound waves that are farther apart have a lower frequency. The frequency of sound waves, in turn, determines the pitch of the sound. Sound waves with a higher frequency produce sound with a higher pitch, and sound waves with a lower frequency produce sound with a lower pitch. "
All sounds begin with vibrations in matter.,(A) true (B) false,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
Sound waves generally travel most quickly through gases.,(A) true (B) false,B,"The speed of most waves depends on the medium through which they are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle. "
Sounds can travel through air and water but not through solids.,(A) true (B) false,B,"Most of the sounds we hear reach our ears through the air, but sounds can also travel through liquids and solids. If you swim underwateror even submerge your ears in bathwaterany sounds you hear have traveled to your ears through the water. Some solids, including glass and metals, are very good at transmitting sounds. Foam rubber and heavy fabrics, on the other hand, tend to muffle sounds. They absorb rather than pass on the sound energy. Q: How can you tell that sounds travel through solids? A: One way is that you can hear loud outdoor sounds such as sirens through closed windows and doors. You can also hear sounds through the inside walls of a house. For example, if you put your ear against a wall, you may be able to eavesdrop on a conversation in the next roomnot that you would, of course. "
Sound waves travel more quickly in warm air than cold air.,(A) true (B) false,A,"Sound waves are mechanical waves, and mechanical waves can only travel through matter. The matter through which the waves travel is called the medium (plural, media). The Table 1.1 gives the speed of sound in several different media. Generally, sound waves travel most quickly through solids, followed by liquids, and then by gases. Particles of matter are closest together in solids and farthest apart in gases. When particles are closer together, they can more quickly pass the energy of vibrations to nearby particles. Medium (20  C) Dry Air Speed of Sound Waves (m/s) 343 Medium (20  C) Water Wood Glass Aluminum Speed of Sound Waves (m/s) 1437 3850 4540 6320 Q: The table gives the speed of sound in dry air. Do you think that sound travels more or less quickly through air that contains water vapor? (Hint: Compare the speed of sound in water and air in the table.) A: Sound travels at a higher speed through water than air, so it travels more quickly through air that contains water vapor than it does through dry air. "
The amount of water vapor in the air affects the speed of sound through air.,(A) true (B) false,A,"The speed of sound is the distance that sound waves travel in a given amount of time. You probably already know that sound travels more slowly than light. Thats why you usually see the flash of lightning before you hear the boom of thunder. However, the speed of sound isnt constant. It varies depending on the medium of the sound waves. Table 20.1 lists the speed of sound in several different media. Generally, sound waves travel fastest through solids and slowest through gases. Thats because the particles of solids are close together and can quickly pass the energy of vibrations to nearby particles. You can explore the speed of sound in different media at this URL:  Medium (20C) Air Water Wood Glass Aluminum Speed of Sound Waves (m/s) 343 1437 3850 4540 6320 The speed of sound also depends on the temperature of the medium. For a given medium such as air, sound has a slower speed at lower temperatures. You can compare the speed of sound in air at different temperatures in Table transfer the energy of the sound waves. The amount of water vapor in the air affects the speed of sound as well. Do you think sound travels faster or slower when the air contains more water vapor? (Hint: Compare the speed of sound in water and air in Table 20.1.) Temperature of Air 0C 20C 100C Speed of Sound (m/s) 331 343 386 KQED: Speed of Sound Along with cable cars and seagulls, the Golden Gate Bridge foghorn is one of San Franciscos most iconic sounds. But did you know that if you hear that foghorn off in the distance, you can calculate how many miles you are from the bridge? Using the Speed of Sound exhibit at the Outdoor Exploratorium at Fort Mason, Shawn Lani shows us how sound perception is affected by distance. For more information on the speed of sound, see http://science.kqed. MEDIA Click image to the left or use the URL below. URL: "
Sounds that are too high in frequency for humans to hear are called infrasound.,(A) true (B) false,B,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
"As distance from a sound source increases, the area covered by the sound waves decreases.",(A) true (B) false,B,"The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity results from two factors: the amplitude of the sound waves and how far they have traveled from the source of the sound. Amplitude is a measure of the size of sound waves. It depends on the amount of energy that started the waves. Greater amplitude waves have more energy and greater intensity, so they sound louder. As sound waves travel farther from their source, the more spread out their energy becomes. You can see how this works in the Figure 1.2. As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source. Q: Why can low-amplitude sounds like whispers be heard only over short distances? A: The sound waves already have so little energy that spreading them out over a wider area quickly reduces their intensity below the level of hearing. "
"As the decibel level of sounds gets higher, the pitch of the sounds always gets higher.",(A) true (B) false,B,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
The intensity of sound waves is the same regardless of distance from the sound source.,(A) true (B) false,B,"The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity results from two factors: the amplitude of the sound waves and how far they have traveled from the source of the sound. Amplitude is a measure of the size of sound waves. It depends on the amount of energy that started the waves. Greater amplitude waves have more energy and greater intensity, so they sound louder. As sound waves travel farther from their source, the more spread out their energy becomes. You can see how this works in the Figure 1.2. As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source. Q: Why can low-amplitude sounds like whispers be heard only over short distances? A: The sound waves already have so little energy that spreading them out over a wider area quickly reduces their intensity below the level of hearing. "
"Some animals can hear sounds with frequencies as high as 100,000 Hz.",(A) true (B) false,A,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
how loud or soft a sound seems to a listener,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,A,"Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is determined, in turn, by the intensity of the sound waves. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). "
"sounds with frequencies above 20,000 hertz",(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,F,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
unit of sound intensity,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,D,"Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is determined, in turn, by the intensity of the sound waves. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). "
how high or low a sound seems to a listener,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,G,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
transfer of energy from a vibrating object in waves that travel through matter,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,C,"Electromagnetic waves are waves that consist of vibrating electric and magnetic fields. Like other waves, electro- magnetic waves transfer energy from one place to another. The transfer of energy by electromagnetic waves is called electromagnetic radiation. Electromagnetic waves can transfer energy through matter or across empty space. Click image to the left or use the URL below. URL:  Q: How do microwaves transfer energy inside a microwave oven? A: They transfer energy through the air inside the oven to the food. "
sounds with frequencies below 20 hertz,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,B,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
measure of the amount of energy in sound waves,(A) loudness (B) infrasound (C) sound (D) decibel (E) intensity (F) ultrasound (G) pitch,E,"Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is determined, in turn, by the intensity of the sound waves. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). "
Bones in the ear canal transmit sound waves to the middle ear.,(A) true (B) false,B,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in the Figure 1.1, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. Q: Wave amplitude is the maximum distance particles of matter move when a wave passes through them. Why would amplifying the sound waves as they pass through the middle ear improve hearing? A: Amplified sound waves have more energy. This increases the intensity and loudness of the sounds, so they are easier to hear. "
Which choice shows the correct sequence in which sound waves travel through the ear?,(A) ear canal  eardrum  hammer (B) anvil  oval window  ear canal (C) stirrup  pinna  eardrum (D) eardrum  ear canal  cochlea,A,"Hearing is the ability to sense sound. Sound travels through the air in waves, much like the waves you see in the water pictured below ( Figure 1.1). Sound waves in air cause vibrations inside the ears. The ears sense the vibrations. The human ear is pictured below ( Figure 1.2). As you read about it, trace the path of sound waves through the ear. Assume a car horn blows in the distance. Sound waves spread through the air from the horn. Some of the sound waves reach your ear. The steps below show what happens next. They explain how your ears sense the sound. 1. The sound waves travel to the ear canal (external auditory canal in the figure). This is a tube-shaped opening in the ear. Sound waves travel through the air in all directions away from a sound, like waves traveling through water away from where a pebble was dropped. Read the names of the parts of the ear in the text; then find each of the parts in the diagram. Note that the round window is distinct from the oval window. 2. At the end of the ear canal, the sound waves hit the eardrum (tympanic membrane). This is a thin membrane that vibrates like the head of a drum when sound waves hit it. 3. The vibrations pass from the eardrum to the hammer (malleus). This is the first of three tiny bones that pass vibrations through the ear. 4. The hammer passes the vibrations to the anvil (incus), the second tiny bone that passes vibrations through the ear. 5. The anvil passes the vibrations to the stirrup (stapes), the third tiny bone that passes vibrations through the ear. 6. From the stirrup, the vibrations pass to the oval window. This is another membrane like the eardrum. 7. The oval window passes the vibrations to the cochlea. The cochlea is filled with liquid that moves when the vibrations pass through, like the waves in water when you drop a pebble into a pond. Tiny hair cells line the cochlea and bend when the liquid moves. When the hair cells bend, they release neurotransmitters. 8. The neurotransmitters trigger nerve impulses that travel to the brain through the auditory nerve (cochlear No doubt youve been warned that listening to loud music or other loud sounds can damage your hearing. Its true. In fact, repeated exposure to loud sounds is the most common cause of hearing loss. The reason? Very loud sounds can kill the tiny hair cells lining the cochlea. The hair cells do not generally grow back once they are destroyed, so this type of hearing loss is permanent. You can protect your hearing by avoiding loud sounds or wearing earplugs or other ear protectors. "
The stirrup passes amplified sound waves to the oval window.,(A) true (B) false,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
In which structure of the ear are sound waves changed to nerve impulses?,(A) eardrum (B) stirrup (C) oval window (D) cochlea,D,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
We hear sound as soon as sound waves reach the middle ear.,(A) true (B) false,B,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
Which structures are found in the outer ear?,(A) anvil (B) pinna (C) eardrum (D) b pinna (E) ear canal (F) eardrum (G) c ear canal (H) cochlea (I) stirrup (J) d hammer (K) pinna (L) ear canal,B,"Figure 20.7 shows the three main parts of the ear: the outer, middle, and inner ear. It also shows the specific structures in each part. The roles of these structures in hearing are described below and in the animations at these URLS:  (1:43) MEDIA Click image to the left or use the URL below. URL: "
Functions of the ossicles include,(A) amplifying sound waves (B) transferring sound waves (C) catching sound waves (D) two of the above,D,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in Figure 20.7, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. They also amplify the vibrations. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. "
Most adults experience at least some hearing loss as they get older.,(A) true (B) false,A,"All these structures of the ear must work well for normal hearing. Damage to any of them, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. To learn more about hearing loss, watch the animation at this URL:  (1:39). MEDIA Click image to the left or use the URL below. URL:  Most adults experience at least some hearing loss as they get older. The most common cause is exposure to loud sounds, which damage hair cells. The louder a sound is, the less exposure is needed for damage to occur. Even a single brief exposure to a sound louder than 115 decibels can cause hearing loss. Figure 20.9 shows the relationship between loudness, exposure time, and hearing loss. "
The most common cause of hearing loss is exposure to loud sounds.,(A) true (B) false,A,"The most common cause of hearing loss is exposure to loud sounds. Loud sounds can damage hair cells inside the ears. Hair cells change sound waves to electrical signals that the brain can interpret as sounds. Louder sounds, which have greater intensity than softer sounds, can damage hair cells more quickly than softer sounds. You can see the relationship between sound intensity, exposure time, and hearing loss in the following Figure 1.1. The intensity of sounds is measured in decibels (dB). Q: What is the maximum amount of time you should be exposed to a sound as intense as 100 dB? What might make a sound this intense? A: You should be exposed to a 100-dB sound for no longer than 15 minutes. An example of a sound this intense is the sound of a car horn. "
Which decibel level of sound has the longest permissible exposure time?,(A) 85 dB (B) 100 dB (C) 106 dB (D) 115 dB,A,"The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. Q: How much louder than a 20-decibel whisper is the 60-decibel sound of a vacuum cleaner? A: The vacuum cleaner is 10,000 times louder than the whisper! "
Long-term exposure to loud sounds is needed to damage hearing.,(A) true (B) false,B,"Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. "
Many home and yard chores are loud enough to cause hearing loss.,(A) true (B) false,A,People who work in jobs that expose them to loud sounds must wear hearing protectors. Examples include construc- tion workers who work around loud machinery for many hours each day (see Figure 20.10). But anyone exposed to loud sounds for longer than the permissible exposure time should wear hearing protectors. Many home and yard chores and even recreational activities are loud enough to cause hearing loss if people are exposed to them for very long. 
Electronic hearing protectors reduce the amplitude of high-amplitude sound waves.,(A) true (B) false,A,"You can see two different types of hearing protectors in the Figure 1.3. Earplugs are simple hearing protectors that just muffle sounds by partially blocking all sound waves from entering the ears. This type of hearing protector is suitable for lower noise levels, such as the noise of a lawnmower or snowmobile. Electronic ear protectors work differently. They identify high-amplitude sound waves and send sound waves through them in the opposite direction. This causes destructive interference with the waves, which reduces their amplitude to zero or nearly zero. This changes even the loudest sounds to just a soft hiss. Sounds that people need to hear, such as the voices of co-workers, are not interfered with in this way and may be amplified instead so they can be heard more clearly. This type of hearing protector is recommended for higher noise levels and situations where its important to be able to hear lower-decibel sounds. "
The brain interprets nerve impulses from the ears as sounds.,(A) true (B) false,A,"What do listening to music and riding a bike have in common? Both activities depend on the ears. The ears are organs that sense sound. They also sense the position of the body and help maintain balance. Hearing is the ability to sense sound. Sound travels through the air in waves. Suppose a car horn blows in the distance. Sound waves spread through the air from the horn. Some of the sound waves enter your ears and cause vibrations. The vibrations trigger nerve impulses that travel to the brain through the auditory nerve. You can learn how this happens in Figure 20.15. The brain then interprets the impulses and tells you what you are hearing. To find out how the brain determines where a sound is coming from, watch this amusing video:  MEDIA Click image to the left or use the URL below. URL:  The parts of the ears involved in balance are the semicircular canals. These are the curved structures above the cochlea in the inner ear in Figure 20.15. Like the cochlea, the semicircular canals contain liquid and are lined with tiny hair cells. As the head changes position, the liquid moves. This causes the hair cells to bend. The bending of the hair cells triggers nerve impulses that travel to the cerebellum in the brain. The cerebellum uses the information to maintain balance. "
Materials used for earplugs include silicon and polyurethane foam.,(A) true (B) false,A,"You can see two different types of hearing protectors in Figure 20.11. Earplugs are simple hearing protectors that just muffle sounds by partially blocking all sound waves from entering the ears. This type of hearing protector is suitable for lower noise levels, such as the noise of a lawnmower or snowmobile engine. Electronic ear protectors work differently. They identify high-amplitude sound waves and send sound waves through them in the opposite direction. This causes destructive interference with the waves, which reduces their amplitude to zero or nearly zero. This changes even the loudest sounds to just a soft hiss. Sounds that people need to hear, such as the voices of co-workers, are not interfered with in this way and may be amplified instead so they can be heard more clearly. This type of hearing protector is recommended for higher noise levels and situations where its important to be able to hear lower-decibel sounds. "
The brain plays an essential role in hearing.,(A) true (B) false,A,"The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. "
part of the ear that extends outward from the head,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,D,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
The most common cause of hearing loss is damage to the eardrum.,(A) true (B) false,B,"All these structures of the ear must work well for normal hearing. Damage to any of them, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. To learn more about hearing loss, watch the animation at this URL:  (1:39). MEDIA Click image to the left or use the URL below. URL:  Most adults experience at least some hearing loss as they get older. The most common cause is exposure to loud sounds, which damage hair cells. The louder a sound is, the less exposure is needed for damage to occur. Even a single brief exposure to a sound louder than 115 decibels can cause hearing loss. Figure 20.9 shows the relationship between loudness, exposure time, and hearing loss. "
any of three tiny bones in the middle ear,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,G,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in Figure 20.7, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. They also amplify the vibrations. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. "
fluid-filled structure in the inner ear that is lined with hair cells,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,C,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
The role of hearing protectors is to keep foreign objects out of the ears.,(A) true (B) false,B,"You can see two different types of hearing protectors in the Figure 1.3. Earplugs are simple hearing protectors that just muffle sounds by partially blocking all sound waves from entering the ears. This type of hearing protector is suitable for lower noise levels, such as the noise of a lawnmower or snowmobile. Electronic ear protectors work differently. They identify high-amplitude sound waves and send sound waves through them in the opposite direction. This causes destructive interference with the waves, which reduces their amplitude to zero or nearly zero. This changes even the loudest sounds to just a soft hiss. Sounds that people need to hear, such as the voices of co-workers, are not interfered with in this way and may be amplified instead so they can be heard more clearly. This type of hearing protector is recommended for higher noise levels and situations where its important to be able to hear lower-decibel sounds. "
tube that carries sound waves into the ear,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,B,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
The eardrum is the first structure of the ear to vibrate when sound waves strike it.,(A) true (B) false,A,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
Waves in cochlear fluid bend the hair-like projections of hair cells.,(A) true (B) false,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
membrane in the outer ear that vibrates when sound waves strike it,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,E,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
tiny structure in the inner ear that changes vibrations to nerve impulses,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,F,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
part of the ear that transmits and amplifies vibrations from the eardrum,(A) middle ear (B) ear canal (C) cochlea (D) pinna (E) eardrum (F) hair cell (G) ossicle,A,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
The arrangement of the ossicles in the middle ear allows them to work together as a(n),(A) inclined plane (B) wedge (C) screw (D) lever,D,"The middle ear contains three tiny bones (ossicles) called the hammer, anvil, and stirrup. If you look at these bones in Figure 20.7, you might notice that they resemble the objects for which they are named. The three bones transmit vibrations from the eardrum to the inner ear. They also amplify the vibrations. The arrangement of the three bones allows them to work together as a lever that increases the amplitude of the waves as they pass to the inner ear. "
"When the oval window in the ear vibrates, it causes vibrations in the",(A) anvil (B) cochlea (C) hammer (D) eardrum,B,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
Which of the following ear structures is damaged by excessive exposure to loud sounds?,(A) pinna (B) ossicle (C) hair cell (D) ear canal,C,"All these structures of the ear must work well for normal hearing. Damage to any of them, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. To learn more about hearing loss, watch the animation at this URL:  (1:39). MEDIA Click image to the left or use the URL below. URL:  Most adults experience at least some hearing loss as they get older. The most common cause is exposure to loud sounds, which damage hair cells. The louder a sound is, the less exposure is needed for damage to occur. Even a single brief exposure to a sound louder than 115 decibels can cause hearing loss. Figure 20.9 shows the relationship between loudness, exposure time, and hearing loss. "
"When the cochlea vibrates, it causes",(A) waves to pass through the cochlear fluid (B) sound waves to increase in frequency (C) the ossicles to start vibrating faster (D) two of the above,A,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
Hearing loss due to exposure to loud sounds is,(A) common (B) permanent (C) preventable (D) all of the above,D,"Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. "
Activities that may expose people to dangerously loud sounds include,(A) lawn mowing (B) snowmobile riding (C) construction work (D) all of the above,D,People who work in jobs that expose them to loud sounds must wear hearing protectors. Examples include construc- tion workers who work around loud machinery for many hours each day (see Figure 20.10). But anyone exposed to loud sounds for longer than the permissible exposure time should wear hearing protectors. Many home and yard chores and even recreational activities are loud enough to cause hearing loss if people are exposed to them for very long. 
Which statement about electronic hearing protectors is true?,(A) They muffle all sounds (B) They generate anti-noise sound waves (C) They send electronic signals to the brain (D) They use insulation to block sound waves,B,"You can see two different types of hearing protectors in the Figure 1.3. Earplugs are simple hearing protectors that just muffle sounds by partially blocking all sound waves from entering the ears. This type of hearing protector is suitable for lower noise levels, such as the noise of a lawnmower or snowmobile. Electronic ear protectors work differently. They identify high-amplitude sound waves and send sound waves through them in the opposite direction. This causes destructive interference with the waves, which reduces their amplitude to zero or nearly zero. This changes even the loudest sounds to just a soft hiss. Sounds that people need to hear, such as the voices of co-workers, are not interfered with in this way and may be amplified instead so they can be heard more clearly. This type of hearing protector is recommended for higher noise levels and situations where its important to be able to hear lower-decibel sounds. "
use of ultrasound to locate underwater objects,(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,B,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
Resonance is used in musical instruments to increase the,(A) frequency of sound waves (B) amplitude of sound waves (C) wavelength of sound waves (D) two of the above,B,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
use of ultrasound to examine structures inside the body,(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,F,"Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see a doctor using ultrasound in the Figure 1.3. "
You can raise the pitch of the sound produced by a violin string by,(A) shortening the part of the string that vibrates (B) plucking instead of bowing the string (C) applying more pressure with the bow (D) none of the above,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
Uses of ultrasound include,(A) creating images of organs inside the body (B) making music with musical instruments (C) communicating with the human voice (D) all of the above,A,"Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see a doctor using ultrasound in the Figure 1.3. "
"sound with a frequency higher than 20,000 hertz",(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,D,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
use of ultrasound by animals to locate objects they cannot see,(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,C,"Animals such as bats and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. You can see in the Figure 1.1 how a bat uses echolocation to find insect prey. "
What does sonar stand for?,(A) source of naval resistance (B) source of noise and resonance (C) sound navigation and ranging (D) submarine navigation and resolution,C,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
vibration of an object in response to sound waves of a certain frequency,(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
Increasing the amplitude of sound waves produced by a musical instrument makes the sound,(A) lower (B) higher (C) softer (D) louder,D,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments for this purpose. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a guitar, the whole instrument and the air inside it may vibrate when a single string is plucked. This causes constructive interference with the sound waves, which increases their amplitude. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds. There are three basic categories of musical instruments: percussion, wind, and stringed instruments. In Figure "
how high or low a sound seems to a listener,(A) resonance (B) sonar (C) echolocation (D) ultrasound (E) pitch (F) ultrasonography,E,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
Basic categories of musical instruments include,(A) wind instruments (B) string instruments (C) percussion instruments (D) all of the above,D,"There are three basic categories of musical instruments: percussion, wind, and stringed instruments. You can read in the Figure 1.1 how instruments in each category make sound and change pitch. Q: Can you name other instruments in each of the three categories of musical instruments? A: Other percussion instruments include drums and cymbals. Other wind instruments include trumpets and flutes. Other stringed instruments include guitars and harps. "
You can change the pitch of a saxophone by,(A) playing the instrument without a reed on the mouthpiece (B) opening or closing holes on the sides of the instrument (C) blowing harder through the instruments mouthpiece (D) none of the above,B,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
The sound of a drum is amplified when the,(A) air inside the drum vibrates (B) skin of the drum is loosened (C) sticks of the drum start to vibrate (D) size of the drum is reduced,A,"The drummer in Figure 17.15 is hitting the drumheads with drumsticks. This causes the drumheads to vibrate. The vibrations pass to surrounding air particles and then from one air particle to another in a wave of energy called sound energy. We hear sound when the sound waves reach our ears. Sound energy can travel through air, water, and other substances, but not through empty space. Thats because the energy needs particles of matter to pass it on. "
All of the following instruments are wind instruments except,(A) flutes (B) violins (C) trumpets (D) saxophones,B,"There are three basic categories of musical instruments: percussion, wind, and stringed instruments. You can read in the Figure 1.1 how instruments in each category make sound and change pitch. Q: Can you name other instruments in each of the three categories of musical instruments? A: Other percussion instruments include drums and cymbals. Other wind instruments include trumpets and flutes. Other stringed instruments include guitars and harps. "
You play a xylophone by hitting wooden bars with rubber mallets. Which type of musical instrument is a xylophone?,(A) wind instrument (B) string instrument (C) percussion instrument (D) none of the above,C,"There are three basic categories of musical instruments: percussion, wind, and stringed instruments. You can read in the Figure 1.1 how instruments in each category make sound and change pitch. Q: Can you name other instruments in each of the three categories of musical instruments? A: Other percussion instruments include drums and cymbals. Other wind instruments include trumpets and flutes. Other stringed instruments include guitars and harps. "
All musical instruments create sound by causing a reed to vibrate.,(A) true (B) false,B,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
Uses of ultrasound include,(A) sonar (B) echolocation (C) ultrasonography (D) all of the above,D,"Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see a doctor using ultrasound in the Figure 1.3. "
Smaller drums produce higher-frequency sound waves than larger drums.,(A) true (B) false,A,"A marching band is parading down the street. You can hear it coming from several blocks away. When the different instruments finally pass by you, their distinctive sounds can be heard. The tiny piccolos trill their bird-like high notes, and the big tubas rumble out their booming bass notes (see Figure 20.5). Clearly, some sounds are higher or lower than others. But do you know why? How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Recall that the frequency of waves is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of a piccolo, have high-frequency waves. Low-pitched sounds, like the sounds of a tuba, have low-frequency waves. For a video demonstration of frequency and pitch, go to this URL:  (3:20). MEDIA Click image to the left or use the URL below. URL:  To explore an interactive animation of sound wave frequency, go to this URL:  The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Sounds with frequencies above 20,000 hertz are called ultrasound. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogs but not people can hear. The whistles produce a sound with a frequency too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, for example, can hear sounds with frequencies higher than 100,000 Hz. "
Animals that use echolocation include,(A) bats (B) whales (C) dolphins (D) all of the above,D,"Animals such as bats, whales, and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. Figure 20.13 and the animation at the URL below show how a bat uses echolocation to locate insect prey. "
Ultrasound has frequencies lower than 20 hertz.,(A) true (B) false,B,"Ultrasound has frequencies higher than the human ear can detect (higher than 20,000 hertz). Although we cant hear ultrasound, it is very useful. Uses include echolocation, sonar, and ultrasonography. "
Ultrasonography has been used to determine the depth of the ocean.,(A) true (B) false,B,"The people who first mapped the seafloor were aboard military vessels during World War II. As stated in the Earth as a Planet chapter, echo sounders used sound waves to search for submarines, but also produced a map of seafloor depths. Depth sounding continued in earnest after the war. Scientists pieced together the ocean depths to produce bathymetric maps of the seafloor. During WWII and in the decade or so later, echo sounders had only one beam, so they just returned a line showing the depth beneath the ship. Later echo sounders sent out multiple beams and could create a bathymetric map of the seafloor below. We will run a multi-beam echo sounder as we go from Woods Hole out to the Mid-Atlantic Ridge. "
Animals that use echolocation include bats and whales.,(A) true (B) false,A,"Animals such as bats, whales, and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. Figure 20.13 and the animation at the URL below show how a bat uses echolocation to locate insect prey. "
The earliest musical instruments date back to about 1900.,(A) true (B) false,B,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
All musical instruments make sound in the same general way.,(A) true (B) false,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
Instruments use resonance to make sounds higher in pitch.,(A) true (B) false,B,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
A saxophone makes sound when the musician blows across a thin piece of wood.,(A) true (B) false,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
Some animals use reflected sound waves to locate prey.,(A) true (B) false,A,"Animals such as bats and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. You can see in the Figure 1.1 how a bat uses echolocation to find insect prey. "
Sonar works on the same principle as echolocation.,(A) true (B) false,A,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
The only use of ultrasonography is to create images of unborn babies.,(A) true (B) false,B,"Ultrasound can be used to ""see"" inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see an ultrasound image in Figure 20.15. You can see an animation showing how ultrasonography works at this URL: "
Examples of electromagnetic waves include,(A) radio waves (B) light (C) X rays (D) all of the above,D,"Mid-wavelength electromagnetic waves are commonly called light. This range of electromagnetic waves has shorter wavelengths and higher frequencies than radio waves, but not as short and high as X rays and gamma rays. Light includes visible light, infrared light, and ultraviolet light. If you look back at Figure 21.7, you can see where these different types of light waves fall in the electromagnetic spectrum. "
All of the following are examples of electromagnetic waves except,(A) sound waves (B) microwaves (C) gamma rays (D) infrared light,A,"Mid-wavelength electromagnetic waves are commonly called light. This range of electromagnetic waves has shorter wavelengths and higher frequencies than radio waves, but not as short and high as X rays and gamma rays. Light includes visible light, infrared light, and ultraviolet light. If you look back at Figure 21.7, you can see where these different types of light waves fall in the electromagnetic spectrum. "
A vibrating electric field creates a,(A) mechanical wave (B) charged particle (C) magnetic field (D) photon,C,"An electromagnetic wave begins when an electrically charged particle vibrates. The Figure 1.3 shows how this happens. A vibrating charged particle causes the electric field surrounding it to vibrate as well. A vibrating electric field, in turn, creates a vibrating magnetic field. The two types of vibrating fields combine to create an electromagnetic wave. "
An electromagnetic wave begins when a(n),(A) atom loses an electron (B) magnet is connected to a battery (C) charged particle vibrates (D) electron is magnetized,C,"An electromagnetic wave begins when an electrically charged particle vibrates. The Figure 1.3 shows how this happens. A vibrating charged particle causes the electric field surrounding it to vibrate as well. A vibrating electric field, in turn, creates a vibrating magnetic field. The two types of vibrating fields combine to create an electromagnetic wave. "
"As an electromagnetic wave travels through space, it",(A) becomes stronger (B) keeps changing direction (C) loses energy to the medium (D) spreads out over a larger area,D,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
Which of the following waves does not require a medium?,(A) ocean waves (B) earthquake waves (C) sound waves (D) radio waves,D,"Unlike a mechanical transverse wave, which requires a medium, an electromagnetic transverse wave can travel through space without a medium. Waves traveling through a medium lose some energy to the medium. However, when an electromagnetic wave travels through space, no energy is lost, so the wave doesnt get weaker as it travels. However, the energy is ""diluted"" as it spreads out over an ever-larger area as it travels away from the source. This is similar to the way a sound wave spreads out and becomes less intense farther from the sound source. "
Most of the electromagnetic radiation on Earth comes from,(A) the sun (B) radio towers (C) X ray machines (D) microwave ovens,A,"The most important source of electromagnetic radiation on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves that people use depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes. Youll learn about all these types of electromagnetic waves in this chapters lesson on ""The Electromagnetic Spectrum."" "
"When electromagnetic waves strike matter, they may",(A) reflect (B) refract (C) diffract (D) all of the above,D,"When electromagnetic waves strike matter, they may interact with it in the same ways that mechanical waves interact with matter. Electromagnetic waves may: reflect, or bounce back from a surface; refract, or bend when entering a new medium; diffract, or spread out around obstacles. Electromagnetic waves may also be absorbed by matter and converted to other forms of energy. Microwaves are a familiar example. When microwaves strike food in a microwave oven, they are absorbed and converted to thermal energy, which heats the food. "
Which of the following statements about electromagnetic radiation is false?,(A) It provides virtually all the energy for life on Earth (B) It behaves like a wave most of the time (C) Sometimes it behaves like a particle (D) All of its wavelengths are harmful,D,"Electromagnetic radiation occurs in waves of different wavelengths and frequencies. Infrared light and visible light make up just a small part of the full range of electromagnetic radiation, which is called the electromagnetic spectrum. The electromagnetic spectrum is summarized in the diagram in Figure 21.7. On the far left of the diagram are radio waves, which include microwaves. They have the longest wavelengths and lowest frequencies of all electromagnetic waves. They also have the least amount of energy. On the far right are X rays and gamma rays. The have the shortest wavelengths and highest frequencies of all electromagnetic waves. They also have the greatest amount of energy. Between these two extremes, wavelength, frequency, and energy change continuously from one side of the spectrum to the other. Waves in this middle section of the electromagnetic spectrum are commonly called light. As you will read below, the properties of electromagnetic waves influence how the different waves behave and how they can be used. "
Uses of electromagnetic radiation include,(A) cooking (B) communications (C) medicine (D) all of the above,D,"The most important source of electromagnetic radiation on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves that people use depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes. Youll learn about all these types of electromagnetic waves in this chapters lesson on ""The Electromagnetic Spectrum."" "
What do radio waves and sound waves have in common?,(A) Both waves are transverse waves (B) Both waves are mechanical waves (C) Both waves transfer energy (D) Both waves need a medium,C,"Television broadcasts also use radio waves (see Figure 1.2). For TV broadcasts, sounds are encoded with frequency modulation, and pictures are encoded with amplitude modulation. The encoded waves are broadcast from a TV tower. When the waves are received by television sets, they are decoded and changed back to sounds and pictures. "
An electromagnetic wave consists of a vibrating,(A) magnetic field (B) electric field (C) particle of matter (D) two of the above,D,"Electromagnetic waves consist of vibrating electric and magnetic fields. They transfer energy across space as well as through matter. Electromagnetic waves vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves is called the electromagnetic spectrum. It is outlined in the following Figure 1.1. "
"When a charged particle vibrates, it causes the electric field around it to vibrate.",(A) true (B) false,A,"An electromagnetic wave begins when an electrically charged particle vibrates. The Figure 1.3 shows how this happens. A vibrating charged particle causes the electric field surrounding it to vibrate as well. A vibrating electric field, in turn, creates a vibrating magnetic field. The two types of vibrating fields combine to create an electromagnetic wave. "
The two fields of an electromagnetic wave occur at right angles to each other.,(A) true (B) false,A,"As you can see in Figure 21.2, the electric and magnetic fields that make up an electromagnetic wave occur are at right angles to each other. Both fields are also at right angles to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. "
Both fields of an electromagnetic wave vibrate in the same direction that the wave travels.,(A) true (B) false,B,"As you can see in Figure 21.2, the electric and magnetic fields that make up an electromagnetic wave occur are at right angles to each other. Both fields are also at right angles to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. "
The wave-particle theory explains the difference between electromagnetic and mechanical waves.,(A) true (B) false,B,"In 1905, the physicist Albert Einstein developed a new theory about electromagnetic radiation. The theory is often called the wave-particle theory. It explains how electromagnetic radiation can behave as both a wave and a particle. Einstein argued that when an electron returns to a lower energy level and gives off electromagnetic energy, the energy is released as a discrete packet of energy. We now call such a packet of energy a photon. According to Einstein, a photon resembles a particle but moves like a wave. You can see this in the Figure 1.1. The theory posits that waves of photons traveling through space or matter make up electromagnetic radiation. "
Electromagnetic waves cannot travel through matter.,(A) true (B) false,B,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
A vibrating electric field generates a charged particle.,(A) true (B) false,B,"An electromagnetic wave begins when an electrically charged particle vibrates. The Figure 1.3 shows how this happens. A vibrating charged particle causes the electric field surrounding it to vibrate as well. A vibrating electric field, in turn, creates a vibrating magnetic field. The two types of vibrating fields combine to create an electromagnetic wave. "
Electromagnetic waves may spread out and travel around obstacles.,(A) true (B) false,A,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
"When electrons return to lower energy levels, they give off particles of matter.",(A) true (B) false,B,"Bohrs idea of energy levels is still useful today. It helps explain how matter behaves. For example, when chemicals in fireworks explode, their atoms absorb energy. Some of their electrons jump to a higher energy level. When the electrons move back to their original energy level, they give off the energy as light. Different chemicals have different arrangements of electrons, so they give off light of different colors. This explains the blue- and purple- colored fireworks in Figure 5.16. "
All electromagnetic radiation is dangerous except for light.,(A) true (B) false,B,"The shortest-wavelength, highest-frequency electromagnetic waves are X rays and gamma rays. These rays have so much energy that they can pass through many materials. This makes them potentially very harmful, but it also makes them useful for certain purposes. "
"Electromagnetic waves are used for communications, cooking, and medicine.",(A) true (B) false,A,"The most important source of electromagnetic waves on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes. "
Electromagnetic radiation provides the energy that plants need for photosynthesis.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
An electromagnetic wave gains energy as it travels across space.,(A) true (B) false,B,"Electromagnetic waves transfer energy across space as well as through matter. They vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves, shown in the Figure 1.1, is called the electromagnetic spectrum. "
The human eye can detect all frequencies of electromagnetic waves.,(A) true (B) false,B,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
All of the suns electromagnetic radiation travels to Earth.,(A) true (B) false,B,"Most of the energy that reaches the Earths surface comes from the Sun (Figure 1.1). About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths. "
Einstein explained how light can behave both as a wave and as a particle.,(A) true (B) false,A,"In 1905, the physicist Albert Einstein developed a new theory about electromagnetic radiation. The theory is often called the wave-particle theory. It explains how electromagnetic radiation can behave as both a wave and a particle. Einstein argued that when an electron returns to a lower energy level and gives off electromagnetic energy, the energy is released as a discrete packet of energy. We now call such a packet of energy a photon. According to Einstein, a photon resembles a particle but moves like a wave. You can see this in the Figure 1.1. The theory posits that waves of photons traveling through space or matter make up electromagnetic radiation. "
transfer of energy by waves such as radio waves and light,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,E,"Electromagnetic waves transfer energy across space as well as through matter. They vary in their wavelengths and frequencies, and higher-frequency waves have more energy. The full range of wavelengths of electromagnetic waves, shown in the Figure 1.1, is called the electromagnetic spectrum. "
explanation for how light can behave as both a wave and a particle,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,F,"Electromagnetic radiation behaves like waves of energy most of the time, but sometimes it behaves like particles. As evidence accumulated for this dual nature of electromagnetic radiation, the famous physicist Albert Einstein developed a new theory about electromagnetic radiation, called the wave-particle theory. This theory explains how electromagnetic radiation can behave as both a wave and a particle. In brief, when an electron returns to a lower energy level, it is thought to give off a tiny ""packet"" of energy called a photon (see Figure 21.3). The amount of energy in a photon may vary. It depends on the frequency of electromagnetic radiation. The higher the frequency is, the more energy a photon has. "
invisible area of force surrounding a charged particle,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,G,"Electric force is exerted over a distance, so charged particles do not have to be in contact in order to exert force over each other. Thats because each charged particle is surrounded by an electric field. An electric field is a space around a charged particle where the particle exerts electric force on other particles. Electric fields surrounding positively and negatively charged particles are illustrated in Figure 23.4 and at the URL below. When charged particles exert force on each other, their electric fields interact. This is also illustrated in Figure 23.4. "
wave in which vibrations occur at right angles to the direction the wave travels,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,D,"As you can see in Figure 21.2, the electric and magnetic fields that make up an electromagnetic wave occur are at right angles to each other. Both fields are also at right angles to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. "
packet of electromagnetic energy,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,A,"Electromagnetic radiation behaves like waves of energy most of the time, but sometimes it behaves like particles. As evidence accumulated for this dual nature of electromagnetic radiation, the famous physicist Albert Einstein developed a new theory about electromagnetic radiation, called the wave-particle theory. This theory explains how electromagnetic radiation can behave as both a wave and a particle. In brief, when an electron returns to a lower energy level, it is thought to give off a tiny ""packet"" of energy called a photon (see Figure 21.3). The amount of energy in a photon may vary. It depends on the frequency of electromagnetic radiation. The higher the frequency is, the more energy a photon has. "
wave that consists of vibrating electric and magnetic fields,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,B,"An electromagnetic wave is a wave that consists of vibrating electric and magnetic fields. A familiar example will help you understand the fields that make up an electromagnetic wave. Think about a common bar magnet. It exerts magnetic force in an area surrounding it, called the magnetic field. You can see the magnetic field of a bar magnet in Figure 21.1. Because of this force field, a magnet can exert force on objects without touching them. They just have to be in its magnetic field. An electric field is similar to a magnetic field (see Figure 21.1). An electric field is an area of electrical force surrounding a charged particle. Like a magnetic field, an electric field can exert force on objects over a distance without actually touching them. "
invisible area of force surrounding a magnet,(A) photon (B) electromagnetic wave (C) magnetic field (D) transverse wave (E) electromagnetic radiation (F) wave-particle theory (G) electric field,C,"Like the electric field that surrounds a charged particle, a magnetic field surrounds a magnet. This is the area around the magnet where it exerts magnetic force. Figure 24.3 shows the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. To see an animated magnetic field of a bar magnet, go to this URL: http://elgg.norfolk.e2bn.org/jsmith112/files/68/149/ When two magnets are brought close together, their magnetic fields interact. You can see how in Figure 24.4. The drawings show how lines of force of north and south poles attract each other whereas those of two north poles repel each other. The animations at the URL below show how magnetic field lines change as two or more magnets move in relation to each other. You can take an animated quiz to check your understanding of magnetic field interactions at this URL: http://elgg. "
How long does it take electromagnetic radiation to reach Earth from the sun?,(A) 1 second (B) 75 seconds (C) 8 minutes (D) 93 minutes,C,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
What happens to light when it passes from water to air?,(A) Its speed decreases (B) Its frequency increases (C) Its wavelength decreases (D) none of the above,D,"Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent where light travels from water to air. Light travels more quickly in air than in water and changes direction. Scattering occurs when light bumps into tiny particles of matter and spreads out in all directions. In the Figure air, giving the headlights a halo appearance. Q: What might be another example of light scattering? A: When light passes through smoky air, it is scattered by tiny particles of soot. "
"If the frequency of an electromagnetic wave is 6.0  108 hertz, what is its wavelength?",(A) 05 m (B) 10 m (C) 15 m (D) 20 m,A,"The speed of a wave is a product of its wavelength and frequency. Because all electromagnetic waves travel at the same speed through space, a wave with a shorter wavelength must have a higher frequency, and vice versa. This relationship is represented by the equation: Speed = Wavelength  Frequency The equation for wave speed can be rewritten as: Frequency = Speed Speed or Wavelength = Wavelength Frequency Therefore, if either wavelength or frequency is known, the missing value can be calculated. Consider an electromag- netic wave that has a wavelength of 3 meters. Its speed, like the speed of all electromagnetic waves, is 3.0  108 meters per second. Its frequency can be found by substituting these values into the frequency equation: Frequency = 3.0  108 m/s = 1.0  108 waves/s, or 1.0  108 hertz (Hz) 3.0 m You Try It! Problem: What is the wavelength of an electromagnetic wave that has a frequency of 3.0  108 hertz? For more practice calculating the frequency and wavelength of electromagnetic waves, go to these URLs: "
Electromagnetic waves with the lowest frequencies may have wavelengths as long as,(A) many kilometers (B) a few meters (C) a couple of centimeters (D) a fraction of a millimeter,A,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
Which statement about electromagnetic waves is true?,(A) An electromagnetic wave with a shorter wavelength has a lower frequency (B) All electromagnetic waves travel at the same speed across space (C) All electromagnetic waves are harmful (D) none of the above,B,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
Some electromagnetic waves are extremely harmful.,(A) true (B) false,A,"The shortest-wavelength, highest-frequency electromagnetic waves are X rays and gamma rays. These rays have so much energy that they can pass through many materials. This makes them potentially very harmful, but it also makes them useful for certain purposes. "
All electromagnetic waves travel at the same speed across space.,(A) true (B) false,A,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
It takes electromagnetic radiation 93 minutes to reach Earth from the sun.,(A) true (B) false,B,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
All electromagnetic waves have the same wavelength.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
Electromagnetic waves travel more quickly through a medium than they do across space.,(A) true (B) false,B,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
The frequencies of electromagnetic waves range from 1 to 100 hertz.,(A) true (B) false,B,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
The highest-frequency electromagnetic waves may have frequencies of trillions of hertz.,(A) true (B) false,A,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
The frequency of an electromagnetic wave is inversely related to its wavelength.,(A) true (B) false,A,Wavelength and frequency are defined in the same way for electromagnetic waves as they are for mechanical waves. Both properties are illustrated in Figure 21.5. Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction of a millimeter. Frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electro- magnetic waves range from thousands to trillions of waves per second. Higher frequency waves have greater energy. 
Light is diffracted when it passes from air to water at an angle.,(A) true (B) false,B,"Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent where light travels from water to air. Light travels more quickly in air than in water and changes direction. Scattering occurs when light bumps into tiny particles of matter and spreads out in all directions. In the Figure air, giving the headlights a halo appearance. Q: What might be another example of light scattering? A: When light passes through smoky air, it is scattered by tiny particles of soot. "
Light has a faster speed across space than do any other wavelengths of electromagnetic radiation.,(A) true (B) false,B,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
Electromagnetic waves travel at the same speed in all media.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
"If you know only the wavelength of an electromagnetic wave, you can calculate its frequency.",(A) true (B) false,A,"The speed of a wave is a product of its wavelength and frequency. Because all electromagnetic waves travel at the same speed through space, a wave with a shorter wavelength must have a higher frequency, and vice versa. This relationship is represented by the equation: Speed = Wavelength  Frequency The equation for wave speed can be rewritten as: Speed Speed Frequency = Wavelength or Wavelength = Frequency Therefore, if either wavelength or frequency is known, the missing value can be calculated. Consider an electromag- netic wave that has a wavelength of 3 meters. Its speed, like the speed of all electromagnetic waves, is 3.0  108 meters per second. Its frequency can be found by substituting these values into the frequency equation: Frequency = 3.0108 m/s 3.0 m = 1.0  108 waves/s, or 1.0  108 Hz Q: What is the wavelength of an electromagnetic wave that has a frequency of 3.0  108 hertz? A: Use the wavelength equation: Wavelength = 3.0108 m/s 3.0108 waves/s = 1.0 m "
distance between corresponding points of adjacent waves,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,B,Another important measure of wave size is wavelength. Wavelength is the distance between two corresponding points on adjacent waves (see Figure 19.11). Wavelength can be measured as the distance between two adjacent crests of a transverse wave or two adjacent compressions of a longitudinal wave. It is usually measured in meters. Wavelength is related to the energy of a wave. Short-wavelength waves have more energy than long-wavelength waves of the same amplitude. You can see examples of waves with shorter and longer wavelengths in Figure 19.12. 
fastest known speed in the universe,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,A,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
matter through which an electromagnetic wave may travel,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,F,"As you can see in the Figure 1.3, the electric and magnetic fields that make up an electromagnetic wave are perpendicular (at right angles) to each other. Both fields are also perpendicular to the direction that the wave travels. Therefore, an electromagnetic wave is a transverse wave. However, unlike a mechanical transverse wave, which can only travel through matter, an electromagnetic transverse wave can travel through empty space. When waves travel through matter, they lose some energy to the matter as they pass through it. But when waves travel through space, no energy is lost. Therefore, electromagnetic waves dont get weaker as they travel. However, the energy is diluted as it travels farther from its source because it spreads out over an ever-larger area. "
number of waves that pass a fixed point in a given amount of time,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,C,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
example of electromagnetic radiation,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,E,"The most important source of electromagnetic radiation on Earth is the sun. Electromagnetic waves travel from the sun to Earth across space and provide virtually all the energy that supports life on our planet. Many other sources of electromagnetic waves that people use depend on technology. Radio waves, microwaves, and X rays are examples. We use these electromagnetic waves for communications, cooking, medicine, and many other purposes. Youll learn about all these types of electromagnetic waves in this chapters lesson on ""The Electromagnetic Spectrum."" "
value that equals wavelength multiplied by wave frequency,(A) speed of light (B) wavelength (C) wave frequency (D) wave speed (E) light (F) medium,D,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
Properties of electromagnetic waves include,(A) speed (B) wavelength (C) frequency (D) all of the above,D,Wavelength and frequency are defined in the same way for electromagnetic waves as they are for mechanical waves. Both properties are illustrated in Figure 21.5. Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction of a millimeter. Frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electro- magnetic waves range from thousands to trillions of waves per second. Higher frequency waves have greater energy. 
Light slows down when it,(A) travels across space (B) passes from air to water (C) passes from water to air (D) two of the above,B,"Although the speed of light is constant in a vacuum, light travels at different speeds in different kinds of matter. For example, light travels more slowly in glass than in air. Therefore, when light passes from air to glass, it slows down. If light strikes a sheet of glass straight on, or perpendicular to the glass, it slows down but passes straight through. However, if light enters the glass at an angle other than 90 , the wave refracts, or bends. This is illustrated in Figure change in speed, the more light bends. "
Electromagnetic waves may vary in their,(A) speed across space (B) energy level (C) frequency (D) two of the above,D,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
Wavelengths of electromagnetic waves range from,(A) many kilometers to a tiny fraction of a millimeter (B) millions of kilometers to several meters (C) several meters to a few millimeters (D) one kilometer to one millimeter,A,"Mid-wavelength electromagnetic waves are commonly called light. This range of electromagnetic waves has shorter wavelengths and higher frequencies than radio waves, but not as short and high as X rays and gamma rays. Light includes visible light, infrared light, and ultraviolet light. If you look back at Figure 21.7, you can see where these different types of light waves fall in the electromagnetic spectrum. "
The highest-frequency electromagnetic waves have a frequency of,(A) hundreds of waves per second (B) thousands of waves per second (C) millions of waves per second (D) trillions of waves per second,D,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
"If the wavelength of an electromagnetic wave is 3.0 m, what is its frequency?",(A) 90  102 hertz (B) 60  104 hertz (C) 30  106 hertz (D) 10  108 hertz,D,"The speed of a wave is a product of its wavelength and frequency. Because all electromagnetic waves travel at the same speed through space, a wave with a shorter wavelength must have a higher frequency, and vice versa. This relationship is represented by the equation: Speed = Wavelength  Frequency The equation for wave speed can be rewritten as: Speed Speed Frequency = Wavelength or Wavelength = Frequency Therefore, if either wavelength or frequency is known, the missing value can be calculated. Consider an electromag- netic wave that has a wavelength of 3 meters. Its speed, like the speed of all electromagnetic waves, is 3.0  108 meters per second. Its frequency can be found by substituting these values into the frequency equation: Frequency = 3.0108 m/s 3.0 m = 1.0  108 waves/s, or 1.0  108 Hz Q: What is the wavelength of an electromagnetic wave that has a frequency of 3.0  108 hertz? A: Use the wavelength equation: Wavelength = 3.0108 m/s 3.0108 waves/s = 1.0 m "
"If the frequency of an electromagnetic wave is 3.0  108 hertz, what is its wavelength?",(A) 1 mm (B) 1 cm (C) 1m (D) 1 km,C,"The speed of a wave is a product of its wavelength and frequency. Because all electromagnetic waves travel at the same speed through space, a wave with a shorter wavelength must have a higher frequency, and vice versa. This relationship is represented by the equation: Speed = Wavelength  Frequency The equation for wave speed can be rewritten as: Speed Speed Frequency = Wavelength or Wavelength = Frequency Therefore, if either wavelength or frequency is known, the missing value can be calculated. Consider an electromag- netic wave that has a wavelength of 3 meters. Its speed, like the speed of all electromagnetic waves, is 3.0  108 meters per second. Its frequency can be found by substituting these values into the frequency equation: Frequency = 3.0108 m/s 3.0 m = 1.0  108 waves/s, or 1.0  108 Hz Q: What is the wavelength of an electromagnetic wave that has a frequency of 3.0  108 hertz? A: Use the wavelength equation: Wavelength = 3.0108 m/s 3.0108 waves/s = 1.0 m "
Radio waves have the least amount of energy of all electromagnetic waves.,(A) true (B) false,A,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Which electromagnetic waves are used for cell phone signals?,(A) X rays (B) microwaves (C) gamma rays (D) none of the above,B,"Cell phone signals are carried through the air as microwaves. You can see how this works in the Figure 1.2. A cell phone encodes the sounds of the callers voice in microwaves by changing the frequency of the waves. This is called frequency modulation. The encoded microwaves are then sent from the phone through the air to a cell tower. From the cell tower, the waves travel to a switching center. From there they go to another cell tower and from the tower to the receiver of the person being called. The receiver changes the encoded microwaves back to sounds. Q: Cell towers reach high above the ground. Why do you think such tall towers are used? A: Microwaves can be interrupted by buildings and other obstructions, so cell towers must be placed high above the ground to prevent the interruption of cell phone signals. "
Visible light has higher-frequency waves than ultraviolet light.,(A) true (B) false,B,"Light includes infrared light, visible light, and ultraviolet light. As you can see from the Figure 1.1, light falls roughly in the middle of the electromagnetic spectrum. It has shorter wavelengths and higher frequencies than microwaves, but not as short and high as X rays. Q: Which type of light do you think is harmful to the skin? A: Waves of light with the highest frequencies have the most energy and are harmful to the skin. Use the electro- magnetic spectrum in the Figure 1.1 to find out which of the three types of light have the highest frequencies. "
Which choice lists electromagnetic waves in the correct sequence from higher to lower frequencies?,(A) microwaves (B) infrared light (C) visible light (D) b ultraviolet light (E) X rays (F) gamma rays (G) c X rays (H) ultraviolet light (I) visible light (J) d radio waves (K) microwaves (L) infrared light,C,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
Cell phone transmissions are carried by microwaves.,(A) true (B) false,A,"Cell phone signals are carried through the air as microwaves. You can see how this works in the Figure 1.2. A cell phone encodes the sounds of the callers voice in microwaves by changing the frequency of the waves. This is called frequency modulation. The encoded microwaves are then sent from the phone through the air to a cell tower. From the cell tower, the waves travel to a switching center. From there they go to another cell tower and from the tower to the receiver of the person being called. The receiver changes the encoded microwaves back to sounds. Q: Cell towers reach high above the ground. Why do you think such tall towers are used? A: Microwaves can be interrupted by buildings and other obstructions, so cell towers must be placed high above the ground to prevent the interruption of cell phone signals. "
Electromagnetic waves that have the least amount of energy are,(A) radio waves (B) infrared light (C) visible light (D) ultraviolet light,A,"The shortest-wavelength, highest-frequency electromagnetic waves are X rays and gamma rays. These rays have so much energy that they can pass through many materials. This makes them potentially very harmful, but it also makes them useful for certain purposes. "
What color does the shortest wavelength of visible light appear to the human eye?,(A) red (B) yellow (C) orange (D) violet,D,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
Radar stands for radio detection and recovery.,(A) true (B) false,B,"Radar stands for Radio Detection and Ranging (Figure 1.2). A transmitter sends out radio waves that bounce off the nearest object and then return to a receiver. Weather radar can sense many characteristics of precipitation: its location, motion, intensity, and the likelihood of future precipitation. Doppler radar can also track how fast the precipitation falls. Radar can outline the structure of a storm and can be used to estimate its possible effects. Radar view of a line of thunderstorms. "
Visible light consists of a very wide range of wavelengths.,(A) true (B) false,B,"Visible light consists of a range of wavelengths. The wavelength of visible light determines the color that the light appears. As you can see in Figure 22.4, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between is a continuum of all the other colors of light. Only a few colors of light are represented in the figure. "
X rays are used for,(A) tracking storms (B) killing bacteria (C) screening luggage at airports (D) two of the above,C,"X rays are high-energy electromagnetic waves. They have enough energy to pass through soft tissues such as skin but not enough to pass through bones and teeth, which are very dense. The bright areas on the X ray film in Figure also to screen luggage at airports (see Figure 21.14). Too much X ray exposure may cause cancer. If youve had dental X rays, you may have noticed that a heavy apron was placed over your body to protect it from stray X rays. The apron is made of lead, which X rays cannot pass through. You can learn about the discovery of X rays as well as other uses of X rays at this URL: "
You should protect your skin from ultraviolet light even on cloudy days.,(A) true (B) false,A,"Light with wavelengths shorter than visible light is called ultraviolet light. The term ultraviolet means above violet. Ultraviolet light is the range of light waves that have shorter wavelengths and higher frequencies than violet light in the visible range of light. With higher frequencies than visible light, ultraviolet light has more energy. It can be used to kill bacteria in food and to sterilize surgical instruments. The human skin also makes vitamin D when it is exposed to ultraviolet light. Vitamin D, in turn, is needed for strong bones and teeth. Too much exposure to ultraviolet light can cause sunburn and skin cancer. As the slip, slop, slap slogan suggests, you can protect your skin from ultraviolet light by wearing clothing that covers your skin, applying sunscreen to any exposed areas, and wearing a hat to protect your head from exposure. The SPF, or sun-protection factor, of sunscreen gives a rough idea of how long it protects the skin from sunburn (see Figure 1.3). A sunscreen with a higher SPF value protects the skin longer. Sunscreen must be applied liberally and often to be effective, and no sunscreen is completely waterproof. Q: You should apply sunscreen even on cloudy days. Can you explain why? A: Ultraviolet light can travel through clouds, so it can harm unprotected skin even on cloudy days. "
The only use of X rays is to make images of bones and teeth inside the body.,(A) true (B) false,B,"X rays are high-energy electromagnetic waves. They have enough energy to pass through soft tissues such as skin but not enough to pass through bones and teeth, which are very dense. The bright areas on the X ray film in Figure also to screen luggage at airports (see Figure 21.14). Too much X ray exposure may cause cancer. If youve had dental X rays, you may have noticed that a heavy apron was placed over your body to protect it from stray X rays. The apron is made of lead, which X rays cannot pass through. You can learn about the discovery of X rays as well as other uses of X rays at this URL: "
Gamma rays cannot pass through bones and teeth.,(A) true (B) false,B,"Gamma rays are the most energetic of all electromagnetic waves. They can pass through most materials, including bones and teeth. Nonetheless, even these waves are useful. For example, they can be used to treat cancer. A medical device sends gamma rays the site of the cancer, and the rays destroy the cancerous cells. If you want to learn more about gamma rays, watch the video at the URL below. MEDIA Click image to the left or use the URL below. URL: "
Gamma rays can be used to destroy cancer cells.,(A) true (B) false,A,"The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer. Ironically, the deadly effects of gamma rays can be used to treat cancer. In this type of treatment, a medical device sends out focused gamma rays that target cancerous cells. The gamma rays kill the cells and destroy the cancer. "
Radar is used for tracking storms.,(A) true (B) false,A,"Radar stands for Radio Detection and Ranging (Figure 1.2). A transmitter sends out radio waves that bounce off the nearest object and then return to a receiver. Weather radar can sense many characteristics of precipitation: its location, motion, intensity, and the likelihood of future precipitation. Doppler radar can also track how fast the precipitation falls. Radar can outline the structure of a storm and can be used to estimate its possible effects. Radar view of a line of thunderstorms. "
Ultraviolet light has shorter wavelengths than visible light.,(A) true (B) false,A,"Light with wavelengths shorter than visible light is called ultraviolet light. The term ultraviolet means ""above violet."" Ultraviolet light is the range of light waves that have shorter wavelengths than violet light in the visible spectrum. Humans cant see ultraviolet light, but it is very useful nonetheless. It has higher-frequency waves than visible light, so it has more energy. It can be used to kill bacteria in food and to sterilize laboratory equipment (see Figure 21.12). The human skin also makes vitamin D when it is exposed to ultraviolet light. Vitamin D is needed for strong bones and teeth. You can learn more about ultraviolet light and its discovery at this URL:  MEDIA Click image to the left or use the URL below. URL:  Too much exposure to ultraviolet light can cause sunburn and skin cancer. You can protect your skin from ultraviolet light by wearing clothing that covers your skin and by applying sunscreen to any exposed areas. The SPF, or sun- protection factor, of sunscreen gives a rough idea of how long it protects the skin from sunburn (see Figure 21.13). A sunscreen with a higher SPF protects the skin longer. You should use sunscreen with an SPF of at least 15 even on cloudy days, because ultraviolet light can travel through clouds. Sunscreen should be applied liberally and often. You can learn more about the effects of ultraviolet light on the skin at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Which of the following choices lists electromagnetic waves from lower to higher frequencies?,(A) radio waves (B) infrared light (C) microwaves (D) b ultraviolet light (E) infrared light (F) X rays (G) c infrared light (H) ultraviolet light (I) gamma rays (J) d visible light (K) microwaves (L) ultraviolet light,C,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
Television broadcasts cannot pass through the ionosphere.,(A) true (B) false,B,"Within the thermosphere is the ionosphere. The ionosphere gets its name from the solar radiation that ionizes gas molecules to create a positively charged ion and one or more negatively charged electrons. The freed electrons travel within the ionosphere as electric currents. Because of the free ions, the ionosphere has many interesting characteristics. At night, radio waves bounce off the ionosphere and back to Earth. This is why you can often pick up an AM radio station far from its source at night. "
Which electromagnetic waves have a wavelength about as wide as the nucleus of an atom?,(A) radio waves (B) infrared light (C) ultraviolet light (D) gamma rays,D,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
"Compared with FM radio broadcasts, AM radio broadcasts can",(A) carry more information (B) be heard more clearly (C) pass through the ionosphere (D) travel to more distant receivers,D,"In radio broadcasts, sounds are encoded in radio waves that are sent out through the atmosphere from a radio tower. A receiver detects the radio waves and changes them back to sounds. Youve probably listened to both AM and FM radio stations. How sounds are encoded in radio waves differs between AM and FM broadcasts. AM stands for amplitude modulation. In AM broadcasts, sound signals are encoded by changing the amplitude of radio waves. AM broadcasts use longerwavelength radio waves than FM broadcasts. Because of their longer wavelengths, AM radio waves reflect off a layer of the upper atmosphere called the ionosphere. You can see how this happens in Figure 21.8. This allows AM radio waves to reach radio receivers that are very far away from the radio tower. FM stands for frequency modulation. In FM broadcasts, sound signals are encoded by changing the frequency of radio waves. Frequency modulation allows FM waves to encode more information than does amplitude modulation, so FM broadcasts usually sound clearer than AM broadcasts. However, because of their shorter wavelength, FM waves do not reflect off the ionosphere. Instead, they pass right through it and out into space (see Figure 21.8). As a result, FM waves cannot reach very distant receivers. "
Television broadcasts encode pictures with amplitude modulation.,(A) true (B) false,A,"Television broadcasts also use radio waves (see Figure 1.2). For TV broadcasts, sounds are encoded with frequency modulation, and pictures are encoded with amplitude modulation. The encoded waves are broadcast from a TV tower. When the waves are received by television sets, they are decoded and changed back to sounds and pictures. "
Television broadcasts encode pictures by changing the,(A) frequency of radio waves (B) amplitude of radio waves (C) wavelength of radio waves (D) speed of radio waves,B,"Television broadcasts also use radio waves. Sounds are encoded with frequency modulation, and pictures are encoded with amplitude modulation. The encoded radio waves are broadcast from a TV tower like the one in Figure 21.9. When the waves are received by television sets, they are decoded and changed back to sounds and pictures. "
Infrared light is used to sterilize surgical instruments.,(A) true (B) false,B,"Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. "
X rays cannot pass through lead.,(A) true (B) false,A,"X rays are high-energy electromagnetic waves. They have enough energy to pass through soft tissues such as skin but not enough to pass through bones and teeth, which are very dense. The bright areas on the X ray film in Figure also to screen luggage at airports (see Figure 21.14). Too much X ray exposure may cause cancer. If youve had dental X rays, you may have noticed that a heavy apron was placed over your body to protect it from stray X rays. The apron is made of lead, which X rays cannot pass through. You can learn about the discovery of X rays as well as other uses of X rays at this URL: "
Which type of electromagnetic waves are used for radar?,(A) ultraviolet waves (B) radar waves (C) microwaves (D) X rays,C,Electromagnetic waves carry energy through matter or space as vibrating electric and magnetic fields. Electromag- netic waves have a wide range of wavelengths and frequencies. The complete range is called the electromagnetic spectrum. The Figure 1.1 shows all the waves of the spectrum. The waves used in radar guns are microwaves. 
Visible light with the longest wavelength appears to be,(A) violet (B) green (C) blue (D) red,D,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
Uses of ultraviolet light include,(A) killing bacteria (B) sterilizing surgical instruments (C) making vitamin D by the skin (D) all of the above,D,"Light with wavelengths shorter than visible light is called ultraviolet light. The term ultraviolet means above violet. Ultraviolet light is the range of light waves that have shorter wavelengths and higher frequencies than violet light in the visible range of light. With higher frequencies than visible light, ultraviolet light has more energy. It can be used to kill bacteria in food and to sterilize surgical instruments. The human skin also makes vitamin D when it is exposed to ultraviolet light. Vitamin D, in turn, is needed for strong bones and teeth. Too much exposure to ultraviolet light can cause sunburn and skin cancer. As the slip, slop, slap slogan suggests, you can protect your skin from ultraviolet light by wearing clothing that covers your skin, applying sunscreen to any exposed areas, and wearing a hat to protect your head from exposure. The SPF, or sun-protection factor, of sunscreen gives a rough idea of how long it protects the skin from sunburn (see Figure 1.3). A sunscreen with a higher SPF value protects the skin longer. Sunscreen must be applied liberally and often to be effective, and no sunscreen is completely waterproof. Q: You should apply sunscreen even on cloudy days. Can you explain why? A: Ultraviolet light can travel through clouds, so it can harm unprotected skin even on cloudy days. "
electromagnetic waves with the greatest energy,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,G,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
full range of wavelengths of electromagnetic radiation,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,E,"Electromagnetic radiation occurs in waves of different wavelengths and frequencies. Infrared light and visible light make up just a small part of the full range of electromagnetic radiation, which is called the electromagnetic spectrum. The electromagnetic spectrum is summarized in the diagram in Figure 21.7. On the far left of the diagram are radio waves, which include microwaves. They have the longest wavelengths and lowest frequencies of all electromagnetic waves. They also have the least amount of energy. On the far right are X rays and gamma rays. The have the shortest wavelengths and highest frequencies of all electromagnetic waves. They also have the greatest amount of energy. Between these two extremes, wavelength, frequency, and energy change continuously from one side of the spectrum to the other. Waves in this middle section of the electromagnetic spectrum are commonly called light. As you will read below, the properties of electromagnetic waves influence how the different waves behave and how they can be used. "
electromagnetic waves with wavelengths between infrared and ultraviolet light,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,F,"Mid-wavelength electromagnetic waves are commonly called light. This range of electromagnetic waves has shorter wavelengths and higher frequencies than radio waves, but not as short and high as X rays and gamma rays. Light includes visible light, infrared light, and ultraviolet light. If you look back at Figure 21.7, you can see where these different types of light waves fall in the electromagnetic spectrum. "
light with the shortest wavelengths,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,C,"The only light that people can see is called visible light. It refers to a very narrow range of wavelengths in the electromagnetic spectrum that falls between infrared light and ultraviolet light. Within the visible range, we see light of different wavelengths as different colors of light, from red light, which has the longest wavelength, to violet light, which has the shortest wavelength. You can see the spectrum of colors of visible light in Figure 21.11. When all of the wavelengths are combined, as they are in sunlight, visible light appears white. You can learn more about visible light in the chapter ""Visible Light"" and at the URL below. "
electromagnetic waves with the longest wavelengths,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,A,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
light with the longest wavelengths,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,B,"Light with the longest wavelengths is called infrared light. The term infrared means below red. Infrared light is the range of light waves that have longer wavelengths and lower frequencies than red light in the visible range of light waves. The sun gives off infrared light as do flames and living things. You cant see infrared light waves, but you can feel them as heat. But infrared cameras and night vision goggles can detect infrared light waves and convert them to visible images. "
radio waves with the highest frequencies,(A) radio waves (B) infrared light (C) ultraviolet light (D) microwaves (E) electromagnetic spectrum (F) visible light (G) gamma rays,D,"The shortest wavelength, highest frequency radio waves are called microwaves (see Figure 21.7). Microwaves have more energy than other radio waves. Thats why they are useful for heating food in microwave ovens. Microwaves have other important uses as well, including cell phone transmissions and radar, which is a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns. These uses are described in Figure 21.10. You can learn more about microwaves and their uses in the video at this URL:  (3:23). MEDIA Click image to the left or use the URL below. URL: "
referring to matter that allows all visible light to pass through,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,F,"Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure 22.3. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it. Translucent matter is matter that transmits but scatters light. Light passes through a translucent object but you cannot see clearly through the object because the light is scattered in all directions. The frosted glass doors in the figure are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does both. Examples of opaque objects are solid wooden doors and glass mirrors. A wooden door absorbs most of the light that strikes it and reflects just a few wavelengths of visible light. A mirror, which is a sheet of glass with a shiny metal coating on the back, reflects all the light that strikes it. "
Light bulbs that produce light by electroluminescence include,(A) neon light bulbs (B) vapor light bulbs (C) LED light bulbs (D) all of the above,D,"The classroom in Figure 22.1 has artificial light sources in addition to natural sunlight. There are fluorescent lights on the ceiling of the room. There are also projectors on the ceiling that are shining light on screens. In these and most other artificial light sources, electricity provides the energy and some type of light bulb converts the electrical energy to visible light. How a light bulb produces visible light varies by type of bulb, as you can see in Table 22.1. Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. Other light bulbs produce light by luminescence, so they produce little if any heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use? Type of Light Bulb Incandescent Light Description An incandescent light bulb produces visible light by incandescence. The bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and glows. You can learn more about incandescent light bulbs at the URL below. Fluorescent Light A fluorescent light bulb produces visible light by flu- orescence. The bulb contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. The phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. You can learn more about fluorescent light bulbs at this URL: http://science.discovery.com/videos/deco Type of Light Bulb Neon Light Vapor Light LED Light Description A neon light produces visible light by electrolumines- cence. The bulb is a glass tube that contains the noble gas neon. When electricity passes through the gas, it excites electrons of neon atoms, causing them to give off visible light. Neon produces red light. Other noble gases are also used in lights, and they produce light of different colors. For example, krypton produces violet light, and argon produces blue light. A vapor light produces visible light by electrolumi- nescence. The bulb contains a small amount of solid sodium or mercury as well as a mixture of neon and argon gases. When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. Sodium vapor lights, like these streetlights, produce yellowish light. Mercury vapor lights produce bluish light. Vapor lights are very bright and energy efficient. The bulbs are also long lasting. LED stands for light-emitting diode. This type of light contains a material, called a semi-conductor, which gives off visible light when a current runs through it. LED lights are used for traffic lights and indicator lights on computers, cars, and many other devices. This type of light is very reliable and durable. "
production of visible light in a way that does not require high temperatures,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,D,"Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Luminescence, in turn, can occur in several different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength ultraviolet light and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way, including gemstones such as amethyst, diamond, and emerald. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current passes through it. Gases such as neon, argon, and krypton produce light by this means. The car dash lights in the Figure 1.2 are produced by electroluminescence. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. The jellyfish in the opening photo above produces light by bioluminescence. So does the firefly in the Figure 1.3. Fireflies give off visible light to attract mates. "
You can see clearly through an object that is transparent because all of the light that strikes the object is,(A) transmitted (B) reflected (C) refracted (D) absorbed,A,"An opaque object is one that doesnt let light pass through it. Instead, it reflects or absorbs the light that strikes it. Many objects, such as the leaves pictured in the Figure 1.3, reflect just one or a few wavelengths of visible light and absorb the rest. The wavelengths that are reflected determine the color that an object appears to the human eye. For example, the leaves appear green because they reflect green light and absorb light of other wavelengths. A transparent or translucent material, such as window glass, transmits some or all of the light that strikes it. This means that the light passes through the material rather than being reflected by it. In this case, we see the material because of the transmitted light. Therefore, the wavelength of the transmitted light determines the color that the object appears. Look at the beautiful stained glass windows in the Figure 1.4. The different colors of glass transmit The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes green leaves, the blue light is absorbed and no light is reflected. Q: What color do you see if an object absorbs all of the light that strikes it? A: When all of the light is absorbed, none is reflected, so the object looks black. But black isnt a color of light. Black is the absence of light. "
referring to matter that does not allow visible light to pass through it,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,G,"Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure 22.3. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it. Translucent matter is matter that transmits but scatters light. Light passes through a translucent object but you cannot see clearly through the object because the light is scattered in all directions. The frosted glass doors in the figure are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does both. Examples of opaque objects are solid wooden doors and glass mirrors. A wooden door absorbs most of the light that strikes it and reflects just a few wavelengths of visible light. A mirror, which is a sheet of glass with a shiny metal coating on the back, reflects all the light that strikes it. "
The shortest wavelength of visible light appears to the human eye as the color,(A) red (B) violet (C) yellow (D) magenta,B,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
Why does a blackboard appear black?,(A) It reflects all wavelengths of visible light (B) It absorbs all wavelengths of visible light (C) It reflects only black wavelengths of visible light (D) It absorbs only black wavelengths of visible light,B,"We see an opaque object, such as the apple in Figure 22.6, because it reflects some wavelengths of visible light. The wavelengths that are reflected determine the color that the object appears. For example, the apple in the figure appears red because it reflects red light and absorbs light of other wavelengths. We see a transparent or translucent object, such as the bottle in Figure 22.6, because it transmits light. The wavelength of the transmitted light determines the color that the object appears. For example, the bottle in the figure appears blue because it transmits blue light. The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes a red apple, the blue light is absorbed and no light is reflected. When no light reflects from an object, it looks black. Black isnt a color. It is the absence of light. "
production of visible light by an object that is so hot it glows,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,A,"The sun and other stars produce light because they are so hot. They glow with light due to their extremely high temperatures. This way of producing light is called incandescence. Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Objects that produce light by luminescence are said to be luminous. Luminescence, in turn, can occur in different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength light, such as ultraviolet light, and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current runs through it. Some gases produce light in this way. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. Examples of bioluminescent organisms are pictured in Figure 22.2. You can learn more about bioluminescence in the video at this URL:  Many other objects appear to produce their own light, but they actually just reflect light from another source. The moon is a good example. It appears to glow in the sky from its own light, but in reality it is just reflecting light from the sun. Objects like the moon that are lit up by another source of light are said to be illuminated. Everything you can see that doesnt produce its own light is illuminated. "
passage of light through matter,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,E,"Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent where light travels from water to air. Light travels more quickly in air than in water and changes direction. Scattering occurs when light bumps into tiny particles of matter and spreads out in all directions. In the Figure air, giving the headlights a halo appearance. Q: What might be another example of light scattering? A: When light passes through smoky air, it is scattered by tiny particles of soot. "
Which of the following colors is a primary pigment color?,(A) red (B) blue (C) cyan (D) green,C,"Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow. Q: A color printer needs just three colors of ink to print all of the colors that we can see. Which colors are they? A: The three colors of ink in a color printer are the three primary pigment colors: cyan, magenta, and yellow. These three colors can be combined in different ratios to produce all other colors, so they are the only colors needed for full-color printing. "
referring to matter that transmits but scatters visible light,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,B,"Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure 22.3. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it. Translucent matter is matter that transmits but scatters light. Light passes through a translucent object but you cannot see clearly through the object because the light is scattered in all directions. The frosted glass doors in the figure are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does both. Examples of opaque objects are solid wooden doors and glass mirrors. A wooden door absorbs most of the light that strikes it and reflects just a few wavelengths of visible light. A mirror, which is a sheet of glass with a shiny metal coating on the back, reflects all the light that strikes it. "
substance that colors materials by reflecting light of certain wavelengths and absorbing light of other,(A) incandescence (B) translucent (C) pigment (D) luminescence (E) transmission (F) transparent (G) opaque,C,"Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is chlorophyll, which is found in plants. This dark green pigment absorbs all but green wavelengths of visible light. It is responsible for capturing the light energy needed for photosynthesis. Pigments are also found in paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary pigment colors are the same as the secondary colors of light: cyan, magenta, and yellow. The printer ink cartridges in Figure 22.8 come in just these three colors. They are the only colors needed for full-color printing. "
A luminous object is an object that appears to glow because it is reflecting light from another source.,(A) true (B) false,B,"Many other objects appear to produce their own light, but they actually just reflect light from another source. Being lit by another source is called illumination. The moon in the Figure 1.4 is glowing so brightly that you can see shadows under the trees. It appears to glow from its own light, but its really just illuminated by light from the sun. Everything you can see that doesnt produce its own light is illuminated by light from some other source. "
Some minerals produce visible light when they absorb ultraviolet light.,(A) true (B) false,A,"Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Luminescence, in turn, can occur in several different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength ultraviolet light and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way, including gemstones such as amethyst, diamond, and emerald. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current passes through it. Gases such as neon, argon, and krypton produce light by this means. The car dash lights in the Figure 1.2 are produced by electroluminescence. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. The jellyfish in the opening photo above produces light by bioluminescence. So does the firefly in the Figure 1.3. Fireflies give off visible light to attract mates. "
A neon light produces violet or blue light.,(A) true (B) false,B,"A neon light produces visible light by electroluminescence. In this process, neon or some other gas gives off light when an electric current passes through it. Other halogen gases besides neonincluding krypton and argonalso produce light in this way. The word OPEN in the sign 1.3 is a neon light. It is a long glass tube that contains neon gas. When electricity passes through the gas, it excites electrons of neon atoms, and the electrons jump to a higher energy level. As the excited electrons return to their original energy level, they give off visible light. Neon produces red light. Other gases produce light of different colors. For example, krypton produces violet light, and argon produces blue light. "
An object that reflects all the light that strikes it is opaque.,(A) true (B) false,A,"An opaque object is one that doesnt let light pass through it. Instead, it reflects or absorbs the light that strikes it. Many objects, such as the leaves pictured in the Figure 1.3, reflect just one or a few wavelengths of visible light and absorb the rest. The wavelengths that are reflected determine the color that an object appears to the human eye. For example, the leaves appear green because they reflect green light and absorb light of other wavelengths. A transparent or translucent material, such as window glass, transmits some or all of the light that strikes it. This means that the light passes through the material rather than being reflected by it. In this case, we see the material because of the transmitted light. Therefore, the wavelength of the transmitted light determines the color that the object appears. Look at the beautiful stained glass windows in the Figure 1.4. The different colors of glass transmit The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes green leaves, the blue light is absorbed and no light is reflected. Q: What color do you see if an object absorbs all of the light that strikes it? A: When all of the light is absorbed, none is reflected, so the object looks black. But black isnt a color of light. Black is the absence of light. "
Fireflies glow with visible light because of chemical reactions.,(A) true (B) false,A,"Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Luminescence, in turn, can occur in several different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength ultraviolet light and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way, including gemstones such as amethyst, diamond, and emerald. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current passes through it. Gases such as neon, argon, and krypton produce light by this means. The car dash lights in the Figure 1.2 are produced by electroluminescence. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. The jellyfish in the opening photo above produces light by bioluminescence. So does the firefly in the Figure 1.3. Fireflies give off visible light to attract mates. "
The sun and other stars produce visible light by,(A) fluorescence (B) luminescence (C) incandescence (D) electroluminescence,C,"Most of the visible light on Earth comes from the sun. The sun and other stars produce light because they are so hot. They glow with light due to their extremely high temperatures. This way of producing light is called incandescence. Incandescent light bulbs also produce light in this way. When electric current passes through a wire filament inside an incandescent bulb, the wire gets so hot that it glows. Do you see the glowing filament inside the incandescent light bulb in the Figure 1.1? Q: What are some other sources of incandescent light? A: Flames also produce incandescent light. For example, burning candles, oil lamps, and bonfires produce light in this way. "
Jellyfish and fireflies produce light as a result of,(A) high temperatures (B) chemical reactions (C) absorption of ultraviolet light (D) reflection of light from other sources,B,"Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Luminescence, in turn, can occur in several different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength ultraviolet light and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way, including gemstones such as amethyst, diamond, and emerald. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current passes through it. Gases such as neon, argon, and krypton produce light by this means. The car dash lights in the Figure 1.2 are produced by electroluminescence. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. The jellyfish in the opening photo above produces light by bioluminescence. So does the firefly in the Figure 1.3. Fireflies give off visible light to attract mates. "
Which type of light bulb produces visible light by electroluminescence?,(A) incandescent light bulb (B) vapor light bulb (C) neon light bulb (D) two of the above,D,"The classroom in Figure 22.1 has artificial light sources in addition to natural sunlight. There are fluorescent lights on the ceiling of the room. There are also projectors on the ceiling that are shining light on screens. In these and most other artificial light sources, electricity provides the energy and some type of light bulb converts the electrical energy to visible light. How a light bulb produces visible light varies by type of bulb, as you can see in Table 22.1. Incandescent light bulbs, which produce light by incandescence, give off a lot of heat as well as light, so they waste energy. Other light bulbs produce light by luminescence, so they produce little if any heat. These light bulbs use energy more efficiently. Which types of light bulbs do you use? Type of Light Bulb Incandescent Light Description An incandescent light bulb produces visible light by incandescence. The bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and glows. You can learn more about incandescent light bulbs at the URL below. Fluorescent Light A fluorescent light bulb produces visible light by flu- orescence. The bulb contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. The phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. You can learn more about fluorescent light bulbs at this URL: http://science.discovery.com/videos/deco Type of Light Bulb Neon Light Vapor Light LED Light Description A neon light produces visible light by electrolumines- cence. The bulb is a glass tube that contains the noble gas neon. When electricity passes through the gas, it excites electrons of neon atoms, causing them to give off visible light. Neon produces red light. Other noble gases are also used in lights, and they produce light of different colors. For example, krypton produces violet light, and argon produces blue light. A vapor light produces visible light by electrolumi- nescence. The bulb contains a small amount of solid sodium or mercury as well as a mixture of neon and argon gases. When an electric current passes through the gases, it causes the solid sodium or mercury to change to a gas and emit visible light. Sodium vapor lights, like these streetlights, produce yellowish light. Mercury vapor lights produce bluish light. Vapor lights are very bright and energy efficient. The bulbs are also long lasting. LED stands for light-emitting diode. This type of light contains a material, called a semi-conductor, which gives off visible light when a current runs through it. LED lights are used for traffic lights and indicator lights on computers, cars, and many other devices. This type of light is very reliable and durable. "
An example of opaque matter is a,(A) clear glass window (B) wooden door (C) mirror (D) two of the above,D,"Matter can be classified on the basis of its interactions with light. Matter may be transparent, translucent, or opaque. An example of each type of matter is pictured in the Figure 1.4. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through transparent objects, such as the top panes of the window 1.4, because just about all of the light that strikes them passes through to the other side. Translucent matter is matter that transmits light but scatters the light as it passes through. Light passes through translucent objects but you cannot see clearly through them because the light is scattered in all directions. The frosted glass panes at the bottom of the window 1.4 are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does some combination of both. Examples of opaque objects are objects made of wood, like the shutters in the Figure 1.5. The shutters absorb most of the light that strikes them and reflect just a few wavelengths of visible light. The glass mirror 1.5 is also opaque. Thats because it reflects all of the light that strikes it. "
Light with the longest wavelength appears,(A) red (B) blue (C) green (D) violet,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
A prism separates light into different colors by,(A) reflection (B) refraction (C) scattering (D) transmission,B,"A prism, like the one in Figure 22.5, can be used to separate visible light into its different colors. A prism is a pyramid-shaped object made of transparent matter, usually clear glass. It transmits light but slows it down. When light passes from the air to the glass of the prism, the change in speed causes the light to bend. Different wavelengths of light bend at different angles. This causes the beam of light to separate into light of different wavelengths. What we see is a rainbow of colors. Look back at the rainbow that opened this chapter. Do you see all the different colors of light, from red at the top to violet at the bottom? Individual raindrops act as tiny prisms. They separate sunlight into its different wavelengths and create a rainbow. For an animated version of Figure 22.5, go to the URL: http://en.wikipedia.org/wiki/File:Light_dispersion_conce "
"If only green light strikes a blue object, the object appears",(A) green (B) blue (C) black (D) white,C,"We see an opaque object, such as the apple in Figure 22.6, because it reflects some wavelengths of visible light. The wavelengths that are reflected determine the color that the object appears. For example, the apple in the figure appears red because it reflects red light and absorbs light of other wavelengths. We see a transparent or translucent object, such as the bottle in Figure 22.6, because it transmits light. The wavelength of the transmitted light determines the color that the object appears. For example, the bottle in the figure appears blue because it transmits blue light. The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes a red apple, the blue light is absorbed and no light is reflected. When no light reflects from an object, it looks black. Black isnt a color. It is the absence of light. "
All plants use visible light to make food by photosynthesis.,(A) true (B) false,A,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
The moon is an example of a luminescent object.,(A) true (B) false,B,"Many other objects appear to produce their own light, but they actually just reflect light from another source. Being lit by another source is called illumination. The moon in the Figure 1.4 is glowing so brightly that you can see shadows under the trees. It appears to glow from its own light, but its really just illuminated by light from the sun. Everything you can see that doesnt produce its own light is illuminated by light from some other source. "
The filament of an incandescent light bulb glows because it gets extremely hot.,(A) true (B) false,A,"An incandescent light bulb like the one pictured in the Figure 1.1 produces visible light by incandescence. Incan- descence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light. "
An LED light produces visible light by fluorescence.,(A) true (B) false,B,A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure 1.2 contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. 
You can see clearly through an object that is translucent.,(A) true (B) false,B,"Matter can be classified on the basis of how light interacts with it. Matter may be transparent, translucent, or opaque. Each type of matter is illustrated in Figure 22.3. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through a transparent object, such as the revolving glass doors in the figure, because all the light passes straight through it. Translucent matter is matter that transmits but scatters light. Light passes through a translucent object but you cannot see clearly through the object because the light is scattered in all directions. The frosted glass doors in the figure are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does both. Examples of opaque objects are solid wooden doors and glass mirrors. A wooden door absorbs most of the light that strikes it and reflects just a few wavelengths of visible light. A mirror, which is a sheet of glass with a shiny metal coating on the back, reflects all the light that strikes it. "
A rainbow occurs because raindrops separate light into its different wavelengths.,(A) true (B) false,A,"A prism, like the one in Figure 22.5, can be used to separate visible light into its different colors. A prism is a pyramid-shaped object made of transparent matter, usually clear glass. It transmits light but slows it down. When light passes from the air to the glass of the prism, the change in speed causes the light to bend. Different wavelengths of light bend at different angles. This causes the beam of light to separate into light of different wavelengths. What we see is a rainbow of colors. Look back at the rainbow that opened this chapter. Do you see all the different colors of light, from red at the top to violet at the bottom? Individual raindrops act as tiny prisms. They separate sunlight into its different wavelengths and create a rainbow. For an animated version of Figure 22.5, go to the URL: http://en.wikipedia.org/wiki/File:Light_dispersion_conce "
An apple appears red because it absorbs only red light.,(A) true (B) false,B,"We see an opaque object, such as the apple in Figure 22.6, because it reflects some wavelengths of visible light. The wavelengths that are reflected determine the color that the object appears. For example, the apple in the figure appears red because it reflects red light and absorbs light of other wavelengths. We see a transparent or translucent object, such as the bottle in Figure 22.6, because it transmits light. The wavelength of the transmitted light determines the color that the object appears. For example, the bottle in the figure appears blue because it transmits blue light. The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes a red apple, the blue light is absorbed and no light is reflected. When no light reflects from an object, it looks black. Black isnt a color. It is the absence of light. "
The bluish green color called cyan is a secondary color of light.,(A) true (B) false,A,"The human eye can distinguish only red, green, and blue light. These three colors are called the primary colors of light. All other colors of light can be created by combining the primary colors. Look at the Venn diagram 1.5. Red and green light combine to form yellow light. Red and blue light combine to form magenta light, and blue and green light combine to form cyan light. Yellow, magenta, and cyan are called the secondary colors of light. Look at the center of the diagram, where all three primary colors of light combine. The result is white light. "
"Combining red, green, and blue light produces light that appears to be black.",(A) true (B) false,B,"The human eye can distinguish only red, green, and blue light. These three colors are called the primary colors of light. All other colors of light can be created by combining the primary colors. Look at the Venn diagram 1.5. Red and green light combine to form yellow light. Red and blue light combine to form magenta light, and blue and green light combine to form cyan light. Yellow, magenta, and cyan are called the secondary colors of light. Look at the center of the diagram, where all three primary colors of light combine. The result is white light. "
The primary colors of pigments are the same as the primary colors of light.,(A) true (B) false,B,"Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow. Q: A color printer needs just three colors of ink to print all of the colors that we can see. Which colors are they? A: The three colors of ink in a color printer are the three primary pigment colors: cyan, magenta, and yellow. These three colors can be combined in different ratios to produce all other colors, so they are the only colors needed for full-color printing. "
formation of a clear image by light reflected from a very smooth surface,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,D,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
A convex lens,(A) is thicker at the edges than in the middle (B) forms only real upside-down images (C) may form enlarged or reduced images (D) causes rays of light to diverge,C,"A convex lens is thicker in the middle than at the edges. You can see the shape of a convex lens in the Figure 1.2. A convex lens causes rays of light to converge, or meet, at a point called the focus (F). A convex lens forms either a real or virtual image. It depends on how close the object is to the lens relative to the focus. Q: An example of a convex lens is a hand lens. Which of the three convex lens diagrams in the Figure 1.2 shows how a hand lens makes an image? A: Youve probably looked through a hand lens before. If you have, then you know that the image it produces is right-side up. Therefore, the first diagram must show how a hand lens makes an image. Its the only one that produces a right-side up image. "
device that produces a very focused beam of light of just one wavelength,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,B,"Did you ever see a cat chase after a laser light, like the one in Figure 1.4? A laser is a device that produces a very focused beam of visible light of just one wavelength and color. Waves of laser light are synchronized so the crests and troughs of the waves line up. The diagram in Figure 1.4 shows why a beam of laser light is so focused compared with ordinary light from a flashlight. The following Figure 1.5 provides a closer look at the tube where laser light is created. Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength. At each end of the tube is a concave mirror. The photons of light reflect back and forth in the tube off these mirrors. This focuses the light. The mirror at one end of the tube is partly transparent. A constant stream of photons passes through the transparent part, forming the laser beam. Click image to the left or use the URL below. URL: "
Concave mirrors are used,(A) as side mirrors on cars (B) behind car headlights (C) in compound microscopes (D) in cameras,B,"Some mirrors have a curved rather than flat surface. Curved mirrors can be concave or convex. A concave mirror is shaped like the inside of a bowl. This type of mirror forms either real or virtual images, depending on where the object is placed relative to the focal point. The focal point is the point in front of the mirror where the reflected rays intersect. You can see how concave mirrors form images in Figure 22.13 and in the interactive animation at the URL below. The animation allows you to move an object to see how its position affects the image. Concave mirrors are used behind car headlights. They focus the light and make it brighter. They are also used in some telescopes. "
curving outward like the outside of a bowl,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,A,"The other type of curved mirror, a convex mirror, is shaped like the outside of a bowl. This type of mirror forms only virtual images. The image is always right-side up and smaller than the actual object, which makes the object appear farther away than it really is. You can see how a convex mirror forms an image in Figure 22.14 and in the animation at the URL below. Because of their shape, convex mirrors can gather and reflect light from a wide area. This is why they are used as side mirrors on cars. They give the driver a wider view of the area around the vehicle than a plane mirror would. "
The optical instrument that produces a beam of very focused light is a,(A) laser (B) microscope (C) telescope (D) none of the above,A,"Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. "
Which surface is most likely to result in diffuse reflection?,(A) completely still water in a puddle (B) choppy water in a lake (C) a plane glass mirror (D) a convex mirror,B,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
copy of an object that is formed by reflected or refracted light,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,F,"Reflection is one of several ways that light can interact with matter. Light reflects off surfaces such as mirrors that do not transmit or absorb light. When light is reflected from a smooth surface, it may form an image. An image is a copy of an object that is formed by reflected (or refracted) light. Q: Is an image an actual object? If not, what is it? A: No, an image isnt an actual object. It is focused rays of light that make a copy of an object, like a picture projected on a screen. "
formation of a blurry image by light reflected from a rough surface,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,G,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
A compound microscope contains,(A) convex lenses (B) plane mirror (C) convex mirror (D) two of the above,D,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or more eyepiece lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! For more on light microscopes and the images they create, watch the video at this URL:  (7:29). MEDIA Click image to the left or use the URL below. URL: "
curving inward like the inside of a bowl,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,C,"The other type of curved mirror, a convex mirror, is shaped like the outside of a bowl. This type of mirror forms only virtual images. The image is always right-side up and smaller than the actual object, which makes the object appear farther away than it really is. You can see how a convex mirror forms an image in Figure 22.14 and in the animation at the URL below. Because of their shape, convex mirrors can gather and reflect light from a wide area. This is why they are used as side mirrors on cars. They give the driver a wider view of the area around the vehicle than a plane mirror would. "
study of visible light and the ways it can be used,(A) convex (B) laser (C) concave (D) regular reflection (E) optics (F) image (G) diffuse reflection,E,"Optics is the study of visible light and the ways it can be used to extend human vision and do other tasks. Knowledge of light was needed for the invention of optical instruments such as microscopes, telescopes, and cameras, in addition to optical fibers. These instruments use mirrors and lenses to reflect and refract light and form images. Q: What is an image? A: An image is a copy of an object created by the reflection or refraction of visible light. "
Moving the lens of a camera controls the amount of light that enters the camera.,(A) true (B) false,B,"A camera is an optical instrument that forms and records an image of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image digitally. Regardless of how the image is recorded, all cameras form images in the same basic way, as shown in the Figure 1.3. Light passes through the lens at the front of the camera and enters the camera through an opening called the aperture. As light passes through the lens, it forms a reduced real image. The image focuses on film (or a sensor) at the back of the camera. The lens may be moved back and forth to bring the image into focus. The shutter controls the amount of light that actually strikes the film (or sensor). It stays open longer in dim light to let more light in. "
A laser beam consists of photons of light of a single wavelength.,(A) true (B) false,A,"Did you ever see a cat chase after a laser light, like the one in Figure 1.4? A laser is a device that produces a very focused beam of visible light of just one wavelength and color. Waves of laser light are synchronized so the crests and troughs of the waves line up. The diagram in Figure 1.4 shows why a beam of laser light is so focused compared with ordinary light from a flashlight. The following Figure 1.5 provides a closer look at the tube where laser light is created. Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength. At each end of the tube is a concave mirror. The photons of light reflect back and forth in the tube off these mirrors. This focuses the light. The mirror at one end of the tube is partly transparent. A constant stream of photons passes through the transparent part, forming the laser beam. Click image to the left or use the URL below. URL: "
A reflecting telescope does not refract light.,(A) true (B) false,B,"Humans have been making and using magnifying lenses for thousands of years. The first telescope was built by Galileo in 1608. His telescope used two lenses to make distant objects appear both nearer and larger. Telescopes that use lenses to bend light are called refracting telescopes, or refractors (Figure 23.4). The earliest telescopes were all refractors. Many amateur astronomers still use refractors today. Refractors are good for viewing details within our solar system. Craters on the surface of Earths Moon or the rings around Saturn are two such details. Around 1670, Sir Isaac Newton built a different kind of telescope. Newtons telescope used curved mirrors instead of lenses to focus light. This type of telescope is called a reflecting telescope, or reflector (see Figure 23.5). The mirrors in a reflecting telescope are much lighter than the heavy glass lenses in a refractor. This is important because a refracting telescope must be much stronger to support the heavy glass. Its much easier to precisely make mirrors than to precisely make glass lenses. For that reason, reflectors can be made larger than refractors. Larger telescopes can collect more light. This means that they can study dimmer or more distant objects. The largest optical telescopes in the world today are reflectors. Telescopes can also be made to use both lenses and mirrors. For more on how telescopes were developed, visit http://galileo.rice.edu/sci/instruments/telescope.html . "
Magnifications of all the lenses of a microscope are added to yield the overall magnification of the,(A) true (B) false,B,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or more eyepiece lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! For more on light microscopes and the images they create, watch the video at this URL:  (7:29). MEDIA Click image to the left or use the URL below. URL: "
Light refracts when it enters a new medium at an angle other than 90 .,(A) true (B) false,A,"When light passes from one medium (or type of matter) to another, it changes speed. You can actually see this happen. If light strikes a new substance at an angle, the light appears to bend. This is what explains the straw looking broken in the picture above. So, does light always bend as it travels into a new medium? If light travels straight into a new substance it is not bent. You may know this angle as perpendicular. The light still slows down, just does not appear to bend. Any angle other than perpendicular the light will bend as it slows down. The bending of light is called refraction. Figure 1.1 shows how refraction occurs. Notice that the angle of light changes again as it passes from the glass back to the air. In this case, the speed increases, and the ray of light resumes its initial direction. For a more detailed explanation of refraction, watch this video: Click image to the left or use the URL below. URL: "
Only mirrors reflect light and form images.,(A) true (B) false,B,"Mirrors are usually made of glass with a shiny metal backing that reflects all the light that strikes it. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image the mirror forms. For example, the image may be real or virtual. A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go behind a mirror, so a virtual image doesnt really exist. It just appears to exist to the human eye and brain. "
All mirrors can form virtual images.,(A) true (B) false,A,"Mirrors are usually made of glass with a shiny metal backing that reflects all the light that strikes it. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image the mirror forms. For example, the image may be real or virtual. A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go behind a mirror, so a virtual image doesnt really exist. It just appears to exist to the human eye and brain. "
The image formed by a plane mirror looks exactly like the object in every way.,(A) true (B) false,B,"Most mirrors are plane mirrors. A plane mirror has a flat reflective surface and forms only virtual images. The image formed by a plane mirror is also life sized. But something is different about the image compared with the real object in front of the mirror. Left and right are reversed. Look at the man shaving in Figure 22.12. He is using his right hand to hold the razor, but his image appears to be holding the razor in the left hand. Almost all plane mirrors reverse left and right in this way. "
The focal point of a concave mirror is the point in front of the mirror where reflected rays intersect.,(A) true (B) false,A,"Some mirrors have a curved rather than flat surface. Curved mirrors can be concave or convex. A concave mirror is shaped like the inside of a bowl. This type of mirror forms either real or virtual images, depending on where the object is placed relative to the focal point. The focal point is the point in front of the mirror where the reflected rays meet. You can see how concave mirrors form images in the Figure 1.2. Concave mirrors are used behind car headlights. They focus the light and make it brighter. Concave mirrors are also used in some telescopes. "
A concave mirror can form only virtual images.,(A) true (B) false,B,"Some mirrors have a curved rather than flat surface. Curved mirrors can be concave or convex. A concave mirror is shaped like the inside of a bowl. This type of mirror forms either real or virtual images, depending on where the object is placed relative to the focal point. The focal point is the point in front of the mirror where the reflected rays intersect. You can see how concave mirrors form images in Figure 22.13 and in the interactive animation at the URL below. The animation allows you to move an object to see how its position affects the image. Concave mirrors are used behind car headlights. They focus the light and make it brighter. They are also used in some telescopes. "
The image formed by a convex mirror is always upright and reduced in size.,(A) true (B) false,A,"The other type of curved mirror, a convex mirror, is shaped like the outside of a bowl. This type of mirror forms only virtual images. The image is always right-side up and smaller than the actual object, which makes the object appear farther away than it really is. You can see how a convex mirror forms an image in Figure 22.14 and in the animation at the URL below. Because of their shape, convex mirrors can gather and reflect light from a wide area. This is why they are used as side mirrors on cars. They give the driver a wider view of the area around the vehicle than a plane mirror would. "
Light travels more quickly through glass than through air.,(A) true (B) false,B,"Although the speed of light is constant in a vacuum, light travels at different speeds in different kinds of matter. For example, light travels more slowly in glass than in air. Therefore, when light passes from air to glass, it slows down. If light strikes a sheet of glass straight on, or perpendicular to the glass, it slows down but passes straight through. However, if light enters the glass at an angle other than 90 , the wave refracts, or bends. This is illustrated in Figure change in speed, the more light bends. "
"The more curved the surface of a lens is, the more it refracts light.",(A) true (B) false,A,"Lenses make use of the refraction of light to create images. A lens is a transparent object, typically made of glass, with one or two curved surfaces. The more curved the surface of a lens is, the more it refracts light. Like mirrors, lenses may be concave or convex. "
The lens in a camera is a convex lens.,(A) true (B) false,B,"Lenses make use of the refraction of light to create images. A lens is a transparent object, typically made of glass, with one or two curved surfaces. The more curved the surface of a lens is, the more it refracts light. Like mirrors, lenses may be concave or convex. "
A refracting telescope uses a convex lens to collect and focus light.,(A) true (B) false,A,"Like microscopes, telescopes use convex lenses to make enlarged images. However, telescopes make enlarged images of objectssuch as distant starsthat only appear tiny because they are very far away. There are two basic types of telescopes: reflecting telescopes and refracting telescopes. The two types are compared in the Figure 1.2. They differ in how they collect light, but both use convex lenses to form enlarged images. Click image to the left or use the URL below. URL: "
The image of an object that is formed by a concave mirror is always,(A) real (B) virtual (C) upright (D) none of the above,D,"Some mirrors have a curved rather than flat surface. Curved mirrors can be concave or convex. A concave mirror is shaped like the inside of a bowl. This type of mirror forms either real or virtual images, depending on where the object is placed relative to the focal point. The focal point is the point in front of the mirror where the reflected rays intersect. You can see how concave mirrors form images in Figure 22.13 and in the interactive animation at the URL below. The animation allows you to move an object to see how its position affects the image. Concave mirrors are used behind car headlights. They focus the light and make it brighter. They are also used in some telescopes. "
Which statement about concave lenses is true?,(A) They are thicker in the middle than at the edges (B) They cause rays of light to diverge (C) They form upside-down images (D) They form enlarged images,B,"Concave lenses are thicker at the edges than in the middle. They cause rays of light to diverge, or spread apart. Figure 22.16 shows how a concave lens forms an image. The image is always virtual and on the same side of the lens as the object. The image is also right-side up and smaller than the object. Concave lenses are used in cameras. They focus reduced images inside the camera, where they are captured and stored. You can explore the formation of images by a concave lens with the interactive animation at this URL: http://phet.colorado.edu/sims/geometric-opti "
Whether a convex lens forms a real or virtual image depends on,(A) where the object is located relative to the focus (B) whether the object is placed right-side up (C) how large the object is (D) how curved the lens is,A,"Convex lenses are thicker in the middle than at the edges. They cause rays of light to converge, or meet, at a point called the focus (F). Convex lenses form either real or virtual images. It depends on how close an object is to the lens relative to the focus. Figure 22.17 shows how a convex lens works. You can also interact with an animated convex lens at the URL below. An example of a convex lens is a hand lens. "
Optical instruments include,(A) microscopes (B) telescopes (C) cameras (D) all of the above,D,"Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. "
Both microscopes and telescopes use,(A) concave lenses (B) convex lenses (C) convex mirrors (D) all of the above,B,"Like microscopes, telescopes use convex lenses to make enlarged images. However, telescopes make enlarged images of objectssuch as distant starsthat only appear tiny because they are very far away. There are two basic types of telescopes: reflecting telescopes and refracting telescopes. The two types are compared in the Figure 1.2. They differ in how they collect light, but both use convex lenses to form enlarged images. Click image to the left or use the URL below. URL: "
The image produced by a camera is,(A) virtual (B) enlarged (C) reduced (D) two of the above,D,"A camera is an optical instrument that forms and records an image of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image digitally. Regardless of how the image is recorded, all cameras form images in the same basic way, as shown in the Figure 1.3. Light passes through the lens at the front of the camera and enters the camera through an opening called the aperture. As light passes through the lens, it forms a reduced real image. The image focuses on film (or a sensor) at the back of the camera. The lens may be moved back and forth to bring the image into focus. The shutter controls the amount of light that actually strikes the film (or sensor). It stays open longer in dim light to let more light in. "
A laser device produces a very focused beam of light by,(A) lining up the crests and troughs of light waves (B) using only very high frequencies of light waves (C) using convex lenses to enlarge light waves (D) shining light waves through an optical fiber,A,"Did you ever see a cat chase after a laser light, like the one in Figure 1.4? A laser is a device that produces a very focused beam of visible light of just one wavelength and color. Waves of laser light are synchronized so the crests and troughs of the waves line up. The diagram in Figure 1.4 shows why a beam of laser light is so focused compared with ordinary light from a flashlight. The following Figure 1.5 provides a closer look at the tube where laser light is created. Electrons in a material such as a ruby crystal are stimulated to radiate photons of light of one wavelength. At each end of the tube is a concave mirror. The photons of light reflect back and forth in the tube off these mirrors. This focuses the light. The mirror at one end of the tube is partly transparent. A constant stream of photons passes through the transparent part, forming the laser beam. Click image to the left or use the URL below. URL: "
Structures of the eye that help to focus light include the,(A) iris (B) cornea (C) retina (D) two of the above,B,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
Which statement about the lens of the eye is true?,(A) It is a concave lens (B) Its shape is controlled by muscles (C) It is the only structure in the eye to focus light (D) all of the above,B,"The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps light out of the eye except at the center front of the eye. The cornea is a transparent outer covering of the front of the eye. It protects the eye and also acts as a convex lens. A convex lens is thicker in the middle than at the edges and makes rays of light converge, or meet at a point. The shape of the cornea helps focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. All the light passes through it instead. The pupil controls the amount of light that enters the eye. It automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens of the eye is a convex lens. It fine-tunes the focus so an image forms on the retina at the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not dim light. There are three different types of cones. Each type senses one of the three primary colors of light (red, green, or blue). The optic nerve carries electrical signals from the rods and cones to the brain. Q: The lens of the eye is a convex lens. How would vision be affected if the lens of the eye was concave instead of convex? A: A concave lens causes rays of light to diverge, or spread apart. It forms a virtual image on the same side of the lens at the object being viewed. Therefore, a concave lens would focus the image in front of the eye, not on the retina inside the eye. No signals would be sent to the brain so vision would not be possible. "
Which choice shows the correct order in which light passes through structures of the eye?,(A) lens (B) pupil (C) cornea (D) b pupil (E) cornea (F) lens (G) c cornea (H) pupil (I) lens (J) d cornea (K) lens (L) pupil,C,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
Images form inside the eye on the,(A) cornea (B) iris (C) pupil (D) retina,D,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Why does the pupil of the eye look black?,(A) It reflects only black light (B) It does not reflect any light (C) It consists of a black membrane (D) It absorbs all the light that strikes it,B,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
The colored part of the eye is the,(A) lens (B) rod (C) iris (D) cone,C,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
The function of the structure in question 3 is to,(A) change images to electrical signals (B) fine-tune the focus of light (C) control the size of the pupil (D) adjust the position of the lens,C,"Figure 20.7 shows the three main parts of the ear: the outer, middle, and inner ear. It also shows the specific structures in each part. The roles of these structures in hearing are described below and in the animations at these URLS:  (1:43) MEDIA Click image to the left or use the URL below. URL: "
Functions of the cornea of the eye include,(A) protecting the eye from injury (B) adjusting the position of the lens (C) controlling how much light enters the eye (D) two of the above,A,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
The image formed on the retina by the lens of the eye is,(A) virtual (B) enlarged (C) upside-down (D) two of the above,C,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Electrical signals from the retina reach the brain through the,(A) visual nerve (B) optic nerve (C) optic rod (D) electrical rod,B,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Which statement about myopia is true?,(A) It is also called farsightedness (B) It can be corrected with convex lenses (C) It occurs when the eyeball is longer than normal (D) It causes both near and distant objects to appear blurry,C,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
What happens when the eyeball is shorter than normal?,(A) Images are focused in back of the retina (B) Distant objects are seen clearly (C) Nearby objects appear blurry (D) all of the above,D,"Nearsightedness, or myopia, is the condition in which nearby objects are seen clearly, but distant objects appear blurry. The Figure 1.1 shows how it occurs. The eyeball is longer (from front to back) than normal. This causes images to be focused in front of the retina instead of on the retina. Myopia can be corrected with concave lenses. The lenses focus images farther back in the eye, so they fall on the retina instead of in front of it. Q: Sometimes squinting the eyes can help someone see more clearly. Why do you think this works? A: Squinting may improve focus by slightly changing the shape of the eyes. When you squint, you tighten muscles around the eyes, putting pressure on the eyeballs. "
One function of the cornea is to protect the eye.,(A) true (B) false,A,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
The role of the pupil is to help focus light.,(A) true (B) false,B,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
Images formed by the eye are upright and virtual.,(A) true (B) false,B,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
We can see only if information from the eyes reaches the brain.,(A) true (B) false,A,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Rods can sense dim light but not colors of light.,(A) true (B) false,A,"For animals like us that see in color, it may be hard to imagine a world that appears to be mainly shades of gray. You can get an idea of how many other animals see the world by looking at a black-and-white picture of colorful objects. For example, look at the apple on the tree pictured below ( Figure 1.3). In the top picture, they appear in color, the way you would normally see them. In the bottom picture they appear without color, in shades of gray ( Figure 1.4). Humans with color vision see the apple on this tree; the bright red color of the apple stands out clearly from the green background of leaves. This black-and-white picture gives an idea of how many animals see the world. Dogs and cats would see the green and red colors as shades of gray; they are able to see blue, but red and green appear the same to them. Many animals see just one or two colors. Some see colors that we cannot see. Apes and chimps see the same colors as us. But whereas many animals cannot see colors, some animals see colors that we cannot. The range of color vision of bees and butterflies for example, extends beyond the visible spectrum of light we can see. The leaves of the flowers they pollinate have special ultraviolet patterns which guide the insects deep into the flower. "
The eyes and brain work together to enable vision.,(A) true (B) false,A,"The ability to see is called vision. It depends on both the eyes and the brain. The eyes sense light and form images. The brain interprets the images formed by the eyes and tells us what we are seeing. For a fascinating account of how the brain helps us see, watch this short video:  . MEDIA Click image to the left or use the URL below. URL: "
The pupil helps to focus light that enters the eye.,(A) true (B) false,B,"The function of the eye is to focus light and form images. We see some objects, such as stars and light bulbs, because they give off their own light. However, we see most objects because they reflect light from another source such as the sun. We form images of the objects when some of the reflected light enters our eyes. Look at the parts of the eye in Figure 20.12. Follow the path of light through the eye as you read about it below. 1. Light from an object passes first through the cornea. This is a clear, protective covering on the outside of the eye. 2. Then light passes through the pupil, an opening in the center of the eye. The pupil, which looks black, is surrounded by the colored part of the eye, called the iris. 3. Light entering through the pupil next passes through the lens. The lens is a clear, curved structure, like the lens of a magnifying glass. Along with the cornea, the lens focuses the light on the back of the eye. 4. The back of the eye is covered by a thin layer called the retina. This is where the image of the object normally forms. The retina consists of special light-sensing cells called rods and cones. Rods sense dim light. Cones sense different colors of light. 5. Nerve impulses from rods and cones travel to the optic nerve. It carries the nerve impulses to the brain. "
The lens changes shape to focus images of close or distant objects.,(A) true (B) false,A,"A lens is a transparent object with one or two curved surfaces. It is typically made of glass (or clear plastic in the case of a contact lens). A lens refracts, or bends, light and forms an image. An image is a copy of an objected formed by the refraction (or reflection) of visible light. The more curved the surface of a lens is, the more it refracts the light that passes through it. There are two basic types of lenses: concave and convex. The two types of lenses have different shapes, so they bend light and form images in different ways. "
There are two different types of rods in the retina.,(A) true (B) false,B,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
"The brain interprets signals from the retina as shape, color, and brightness.",(A) true (B) false,A,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
The brain interprets images on the retina as though they were upright.,(A) true (B) false,A,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Laser surgery corrects vision problems by changing the shape of the lens.,(A) true (B) false,B,"Many people have problems with their vision, or ability to see. Often, the problem is due to the shape of the eyes and how they focus light. Two of the most common vision problems are nearsightedness and farsightedness, which you can read about below. You may even have one of these vision problems yourself. Usually, the problems can be corrected with contact lenses or lenses in eyeglasses. In many people, they can also be corrected with laser surgery, which reshapes the outer layer of the eye. Click image to the left or use the URL below. URL: "
The role of the iris is to control the size of the pupil.,(A) true (B) false,A,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
The lens normally focuses images on the optic nerve.,(A) true (B) false,B,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
Hyperopia is also called nearsightedness.,(A) true (B) false,B,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
nerve cell in the retina that senses dim light,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,B,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
colored part of the eye,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,E,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
opening at the front of the eye that lets in light,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,G,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
nerve cell in the retina that senses colors of light,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,D,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
organ specialized to collect light and focus images,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,A,"As just described, the eyes collect and focus visible light. The lens and other structures of the eye work together to focus a real image on the retina. The image is upside-down and reduced in size, as you can see in Figure 22.25. The image reaches the brain as electrical signals that travel through the optic nerve. The brain interprets the signals as shape, color, and brightness. It also interprets the image as though it were right-side up. The brain does this automatically, so what we see is always right-side up. The brain also tells us what we are seeing. "
transparent outer covering of the eye,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,C,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
membrane lining the back of the eye,(A) eye (B) rod (C) cornea (D) cone (E) iris (F) retina (G) pupil,F,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
A maglev train can hover above the track without touching it because of,(A) friction (B) magnetic force (C) static electricity (D) none of the above,B,"Solenoids are the basis of electromagnets. An electromagnet is a solenoid wrapped around a bar of iron or other ferromagnetic material (see Figure 25.6). The electromagnetic field of the solenoid magnetizes the iron bar by aligning its magnetic domains. The combined magnetic force of the magnetized iron bar and the wire coil makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. Some of them are strong enough to lift a train. The maglev train described earlier, in the lesson ""Electricity and Magnetism,"" contains permanent magnets. Strong electromagnets in the track repel the train magnets, causing the train to levitate above the track. Like a solenoid, an electromagnet is stronger if there are more turns in the coil or more current is flowing through it. A bigger bar or one made of material that is easier to magnetize also increases an electromagnets strength. You can see how to make a simple electromagnet at this URL:  (4:57). MEDIA Click image to the left or use the URL below. URL: "
Ferromagnetic materials include,(A) iron (B) nickel (C) cobalt (D) all of the above,D,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
"If a magnet is allowed to move freely, its north and south poles will always",(A) line up with Earths north-south axis (B) keep changing places (C) point east and west (D) repel each other,A,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
How is magnetic force like electric force?,(A) It is caused by moving electrons (B) It generates a force field (C) It acts over a distance (D) all of the above,D,"The force that a magnet exerts on certain materials is called magnetic force. Like electric force, magnetic force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. "
Magnetic domains in a ferromagnetic material are most likely to align in the same direction when the material is,(A) heated to a high temperature (B) placed near a magnet (C) dropped on a hard surface (D) two of the above,B,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
Some magnets have just one magnetic pole.,(A) true (B) false,B,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
Bringing together the north poles of two magnets demagnetizes them.,(A) true (B) false,B,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
A magnet will attract any material that contains iron.,(A) true (B) false,A,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one in Figure 24.2. Like all magnets, this bar magnet has north and south poles and attracts objects such as paper clips that contain iron. "
An atom is a tiny magnet because its electrons spin around its nucleus.,(A) true (B) false,A,"Although atoms are very tiny, they consist of even smaller particles. Atoms are made of protons, neutrons, and electrons: Protons have a positive charge. Electrons have a negative charge. Neutrons are neutral in charge. "
Only ferromagnetic materials are affected by magnetic force.,(A) true (B) false,A,"Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so overall the material is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, there are regions where the north and south poles of atoms are all lined up in the same direction. These regions are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized (made into a magnet) by placing it in a magnetic field. When this happens, all the magnetic domains line up, and the material becomes a magnet. You can see this in the Figure 1.1. Materials that can be magnitized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
Copper and aluminum are attracted by magnets.,(A) true (B) false,B,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one in Figure 24.2. Like all magnets, this bar magnet has north and south poles and attracts objects such as paper clips that contain iron. "
For a ferromagnetic material to become magnetic its magnetic domains must be aligned.,(A) true (B) false,A,"Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so overall the material is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, there are regions where the north and south poles of atoms are all lined up in the same direction. These regions are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized (made into a magnet) by placing it in a magnetic field. When this happens, all the magnetic domains line up, and the material becomes a magnet. You can see this in the Figure 1.1. Materials that can be magnitized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
Iron is the only ferromagnetic material.,(A) true (B) false,B,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
Only temporary magnets can be demagnetized.,(A) true (B) false,B,"Materials that have been magnetized may become temporary or permanent magnets. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains line up. As a result, the paper clips will stick to the magnet and also to each other (see the Figure 1.2). However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. You can see how its done in the Figure 1.3. The nails magnetic domains will remain aligned even after you remove the nail from the magnetic field of the bar magnet. Q: Even permanent magnets can be demagnetized if they are dropped or heated to high temperatures. Can you explain why? "
"While paper clips are clinging to a bar magnet, they are temporary magnets.",(A) true (B) false,A,"Materials that have been magnetized may become temporary or permanent magnets. An example of each type of magnet is described below. Both are demonstrated in Figure 24.7. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains align. As a result, the paper clips will stick to the magnet and also to each other. However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. Its magnetic domains will remain aligned even after you remove it from the magnetic field of the bar magnet. Permanent magnets can be demagnetized, however, if they are dropped or heated to high temperatures. These actions move the magnetic domains out of alignment. "
The most magnetic material in nature is magnetite.,(A) true (B) false,A,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
An iron nail can be turned into a permanent magnet.,(A) true (B) false,A,"Materials that have been magnetized may become temporary or permanent magnets. An example of each type of magnet is described below. Both are demonstrated in Figure 24.7. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains align. As a result, the paper clips will stick to the magnet and also to each other. However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. Its magnetic domains will remain aligned even after you remove it from the magnetic field of the bar magnet. Permanent magnets can be demagnetized, however, if they are dropped or heated to high temperatures. These actions move the magnetic domains out of alignment. "
Permanent magnets can never be demagnetized.,(A) true (B) false,B,"Materials that have been magnetized may become temporary or permanent magnets. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains line up. As a result, the paper clips will stick to the magnet and also to each other (see the Figure 1.2). However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. You can see how its done in the Figure 1.3. The nails magnetic domains will remain aligned even after you remove the nail from the magnetic field of the bar magnet. Q: Even permanent magnets can be demagnetized if they are dropped or heated to high temperatures. Can you explain why? "
Magnetite is a naturally occurring permanent magnet.,(A) true (B) false,A,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
The magnetic properties of lodestone were discovered only recently.,(A) true (B) false,B,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
force of attraction or repulsion exerted by a magnet,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,E,"The force that a magnet exerts on certain materials is called magnetic force. Like electric force, magnetic force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. "
object that attracts ferromagnetic materials,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,B,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one in Figure 24.2. Like all magnets, this bar magnet has north and south poles and attracts objects such as paper clips that contain iron. "
"iron, nickel, or cobalt",(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,A,"Each element has a unique set of properties that make it different from all other elements. As a result, elements can be identified by their properties. For example, the elements iron and nickel are both metals that are good conductors of heat and electricity. However, iron is attracted by a magnet, whereas nickel is not. How could you use this property to separate iron objects from nickel objects? "
north or south end of a magnet,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,F,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one shown in the Figure 1.1. Like all magnets, this bar magnet has north and south magnetic poles. The red end of the magnet is the north pole and the blue end is the south pole. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) Q: What do you suppose would happen if you cut the bar magnet pictured in the Figure 1.1 along the line between the north and south poles? A: Both halves of the magnet would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
area around a magnet where it exerts force,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,D,"Like the electric field that surrounds a charged particle, a magnetic field surrounds a magnet. This is the area around the magnet where it exerts magnetic force. Figure 24.3 shows the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. To see an animated magnetic field of a bar magnet, go to this URL: http://elgg.norfolk.e2bn.org/jsmith112/files/68/149/ When two magnets are brought close together, their magnetic fields interact. You can see how in Figure 24.4. The drawings show how lines of force of north and south poles attract each other whereas those of two north poles repel each other. The animations at the URL below show how magnetic field lines change as two or more magnets move in relation to each other. You can take an animated quiz to check your understanding of magnetic field interactions at this URL: http://elgg. "
ability of a material to respond to and exert magnetic force,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,G,"Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. No doubt youve handled refrigerator magnets like the ones in Figure 24.5. You probably know first-hand that they stick to a metal refrigerator but not to surfaces such as wooden doors and glass windows. Wood and glass arent attracted to a magnet, whereas the steel refrigerator is. Obviously, only certain materials respond to magnetic force. "
area of a ferromagnetic material where the poles of atoms are aligned in the same direction,(A) ferromagnetic material (B) magnet (C) magnetic domain (D) magnetic field (E) magnetic force (F) magnetic pole (G) magnetism,C,"Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the materials have no magnetic properties. Also, in most types of matter, the north and south poles of atoms point in all different directions, so overall the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, electrons fill the orbitals of the atoms that make up the material in a way to allow for each atom to have a tiny magnetic field, giving each atom a tiny north and south pole. There are large areas where the north and south poles of atoms are all lined up in the same direction. These areas are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized by placing it in a magnetic field. When this happens, all the magnetic domains become aligned, and the material becomes a magnet. This is illustrated in Figure 24.6. Materials that can be magnetized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
Why are the poles of a magnet called north and south poles?,(A) One pole is positive and one pole is negative (B) The poles are at opposite ends of the magnet (C) The poles are the coldest parts of the magnet (D) The poles line up with Earths north-south axis,D,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
What happens if you cut a bar magnet in half between the north and south poles?,(A) One half has a north pole and one half has a south pole (B) Each half is a stronger magnet than the original magnet (C) Each half has both a north pole and a south pole (D) The two halves are no longer magnetic,C,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
Which statement about magnetic force is false?,(A) It is exerted over a distance (B) It affects only certain types of matter (C) It includes forces of attraction and repulsion (D) It acts only on materials that are touching a magnet,D,"The force that a magnet exerts on certain materials is called magnetic force. Like electric force, magnetic force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. "
Which of the following materials is attracted to a magnet?,(A) aluminum (B) copper (C) glass (D) steel,D,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one in Figure 24.2. Like all magnets, this bar magnet has north and south poles and attracts objects such as paper clips that contain iron. "
A material that can be magnetized,(A) has magnetic domains (B) is called ferromagnetic (C) must contain iron (D) two of the above,D,"Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure 1.4). The magnetic domains of magnetite naturally align with Earths axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. "
"If you place a paper clip very close to a magnet, the paper clip",(A) is attracted to the magnet (B) moves toward the magnet (C) becomes a temporary magnet (D) all of the above,D,"Materials that have been magnetized may become temporary or permanent magnets. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains line up. As a result, the paper clips will stick to the magnet and also to each other (see the Figure 1.2). However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. You can see how its done in the Figure 1.3. The nails magnetic domains will remain aligned even after you remove the nail from the magnetic field of the bar magnet. Q: Even permanent magnets can be demagnetized if they are dropped or heated to high temperatures. Can you explain why? "
Magnetism is caused by the,(A) attraction between protons and neutrons of atoms (B) attraction between positive and negative ions (C) movement of electrons within atoms (D) none of the above,C,"Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the materials have no magnetic properties. Also, in most types of matter, the north and south poles of atoms point in all different directions, so overall the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, electrons fill the orbitals of the atoms that make up the material in a way to allow for each atom to have a tiny magnetic field, giving each atom a tiny north and south pole. There are large areas where the north and south poles of atoms are all lined up in the same direction. These areas are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized by placing it in a magnetic field. When this happens, all the magnetic domains become aligned, and the material becomes a magnet. This is illustrated in Figure 24.6. Materials that can be magnetized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
The north end of a compass needle always points to 90 north latitude.,(A) true (B) false,B,"Although the needle of a compass always points north, it doesnt point to Earths north geographic pole. Find the north geographic pole in the Figure 1.2. As you can see, it is located at 90 north latitude. Where does a compass Q: The north end of a compass needle points toward Earths north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesnt the north end of a compass needle point to Earths south magnetic pole instead? A: The answer may surprise you. The compass needle actually does point to the south pole of magnet Earth. However, it is called the north magnetic pole because it is close to the north geographic pole. This naming convention was adopted a long time ago to avoid confusion. "
The idea that Earth is a magnet was first proposed in,(A) 1600 (B) 1700 (C) 1800 (D) 1900,A,"The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. However, explaining why Earth acts like a magnet is a relatively recent discovery. It had to wait until the development of technologies such as seismographs, which detect and measure earthquake waves. Then scientists could learn about Earths inner structure (see Figure 24.15). They discovered that Earth has an inner and outer core and that the outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated by the movement of charged particles through the molten metals in the outer core. The particles move as Earth spins on its axis. The video at the URL below takes a closer look at how this occurs. MEDIA Click image to the left or use the URL below. URL: "
Earths magnetic field extends outward from the planet in all directions.,(A) true (B) false,A,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. You can see a model of the magnetosphere in the Figure 1.3. It is a huge region that extends outward from Earth in all directions. Earth exerts magnetic force over the entire field, but the force is strongest at the poles, where lines of force converge. Click image to the left or use the URL below. URL: "
The magnetosphere is,(A) a huge region (B) strongest at the poles (C) the region where Earth exerts magnetic force (D) all of the above,D,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. It is a huge region that extends outward from Earth for several thousand kilometers but is strongest at the poles. You can see the extent of the magnetosphere in Figure 24.12. For an animated version of the magnetosphere, watch the video at this URL: MEDIA Click image to the left or use the URL below. URL: "
Earths magnetic poles have switched places many times over the past hundred years.,(A) true (B) false,B,"Earths magnetic poles have switched places repeatedly in the past. As you can see in the Figure 1.1, each time the switch occurred, Earths magnetic field was reversed. The magnetic field is the region around a magnet over which it exerts magnetic force. We think of todays magnetic field direction as normal, but thats only because its what were used to. "
What causes Earths magnetism?,(A) The movement of charged particles in Earths outer core (B) The revolution of Earth around the sun (C) The magnetism of the sun (D) none of the above,A,"The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. However, explaining why Earth acts like a magnet is a relatively recent discovery. It had to wait until the development of technologies such as seismographs, which detect and measure earthquake waves. Then scientists could learn about Earths inner structure (see Figure 24.15). They discovered that Earth has an inner and outer core and that the outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated by the movement of charged particles through the molten metals in the outer core. The particles move as Earth spins on its axis. The video at the URL below takes a closer look at how this occurs. MEDIA Click image to the left or use the URL below. URL: "
Evidence for magnetic field reversals comes from,(A) rocks on the ocean floor (B) metals in Earths liquid core (C) measurements of Earths magnetosphere (D) seismograph readings from inside Earth,A,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
"Once molten rocks harden, their magnetic domains are frozen in place forever.",(A) true (B) false,A,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
Earths outer core is made up mainly of iron and nickel.,(A) true (B) false,A,"At the planets center lies a dense metallic core. Scientists know that the core is metal because: 1. The density of Earths surface layers is much less than the overall density of the planet, as calculated from the planets rotation. If the surface layers are less dense than average, then the interior must be denser than average. Calculations indicate that the core is about 85% iron metal with nickel metal making up much of the remaining 15%. 2. Metallic meteorites are thought to be representative of the core. The 85% iron/15% nickel calculation above is also seen in metallic meteorites (Figure 1.1). If Earths core were not metal, the planet would not have a magnetic field. Metals such as iron are magnetic, but rock, which makes up the mantle and crust, is not. Scientists know that the outer core is liquid and the inner core is solid because: 1. S-waves do not go through the outer core. 2. The strong magnetic field is caused by convection in the liquid outer core. Convection currents in the outer core are due to heat from the even hotter inner core. The heat that keeps the outer core from solidifying is produced by the breakdown of radioactive elements in the inner core. Click image to the left or use the URL below. URL: "
Earths magnetic field is beneficial to living things because it,(A) protects them from harmful particles (B) can be used for navigation (C) never changes (D) two of the above,D,"Earths magnetic field helps protect Earth and its organisms from harmful particles given off by the sun. Most of the particles are attracted to the north and south magnetic poles, where Earths magnetic field is strongest. This is also where relatively few organisms live. Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural ""compasses"" that work just as well. Birds like the garden warbler in Figure 24.16 use Earths magnetic field to guide their annual migrations. Recent research suggests that warblers and other migrating birds have structures in their eyes that let them see Earths magnetic field as a visual pattern. You can learn more about animals and Earths magnetic field, including the potential effects of magnetic field reversals, at this URL:  . "
Charged particles move inside Earth when it spins on its axis.,(A) true (B) false,A,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
Harmful particles from the sun are repelled by Earths magnetic poles.,(A) true (B) false,B,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
Magnetic reversals were discovered by William Gilbert in 1600.,(A) true (B) false,B,"Do you like to read science fiction? Science fiction writers are really creative. For example, an author might write about a time in the distant past when compasses pointed south instead of north. Actually, this idea isnt fictionits a fact! Earths magnetic poles have switched places repeatedly over the past hundreds of millions of years, each time reversing Earths magnetic field. This is illustrated in Figure 24.13. Scientists dont know for certain why magnetic reversals occur, but there is hard evidence showing that they have occurred. The evidence comes from rocks on the ocean floor. Look at Figure 24.14, which shows a ridge on the ocean floor. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. The newly hardened rock is then gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. Rock samples from many places on the ocean floor reveal that magnetic domains of rocks from different time periods are aligned in opposite directions. The evidence shows that Earths magnetic field reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. What might happen if a magnetic reversal occurred in your lifetime? How might it affect you? You can learn more about Earths magnetic reversals at this URL:  . "
Earths south magnetic pole is the same as Earths south geographic pole.,(A) true (B) false,B,"Like the real Earth, the globe pictured above is a magnet. A magnet is an object that has north and south magnetic poles and a magnetic field. The magnetic globe is a modern device, but the idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. He used a spherical magnet to represent Earth. With a compass, he demonstrated that it the spherical magnet causes a compass needle to behave the same way that Earth causes a compass needle to behave. This showed that a spherical magnet is a good model for Earth and therefore that Earth is a magnet. Q: Can you describe Earths magnetic poles and magnetic field? A: Earth has north and south magnetic poles. The North Pole is located at about 80 degrees north latitude. The magnetic field is an area around Earth that is affected by its magnetic field. The field is strongest at the poles, and lines of magnetic force move from the north to the south magnetic pole. "
Migrating birds may detect Earths magnetic field with structures in their eyes.,(A) true (B) false,A,"Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field and uses it to navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for navigation. Recent research suggests that they may have structures in their eyes that let them see Earths magnetic field as a visual pattern. "
Earth has north and south magnetic poles like a bar magnet.,(A) true (B) false,A,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
"Like a bar magnet, planet Earth",(A) exerts magnetic force (B) has a magnetic field (C) has magnetic poles (D) all of the above,D,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
Earths magnetic and geographic poles are located in the same places.,(A) true (B) false,B,"Like the real Earth, the globe pictured above is a magnet. A magnet is an object that has north and south magnetic poles and a magnetic field. The magnetic globe is a modern device, but the idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. He used a spherical magnet to represent Earth. With a compass, he demonstrated that it the spherical magnet causes a compass needle to behave the same way that Earth causes a compass needle to behave. This showed that a spherical magnet is a good model for Earth and therefore that Earth is a magnet. Q: Can you describe Earths magnetic poles and magnetic field? A: Earth has north and south magnetic poles. The North Pole is located at about 80 degrees north latitude. The magnetic field is an area around Earth that is affected by its magnetic field. The field is strongest at the poles, and lines of magnetic force move from the north to the south magnetic pole. "
Earths true north magnetic pole is actually located near Earths,(A) equator (B) south magnetic pole (C) south geographic pole (D) none of the above,C,"Although a compass always points north, it doesnt point to Earths geographic north pole, which is located at 90 north latitude (see Figure 24.11). Instead, it points to Earths magnetic north pole, which is located at about 80 north latitude. Earths magnetic south pole is also located several degrees of latitude away from the geographic south pole. A compass pointer has north and south poles, and its north pole points to Earths magnetic north pole. Why does this happen if opposite poles attract? Why doesnt the compass needle point south instead? The answer may surprise you. Earths magnetic north pole is actually the south pole of magnet Earth! Its called the magnetic north pole to avoid confusion. Because its close to the geographic north pole, it would be confusing to call it the magnetic south pole. "
Earths magnetic field extends outward from Earth for,(A) a few kilometers (B) about 100 kilometers (C) about 330 kilometers (D) several thousand kilometers,D,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. It is a huge region that extends outward from Earth for several thousand kilometers but is strongest at the poles. You can see the extent of the magnetosphere in Figure 24.12. For an animated version of the magnetosphere, watch the video at this URL: MEDIA Click image to the left or use the URL below. URL: "
Scientists no longer accept the idea of magnetic reversals.,(A) true (B) false,B,"Do you like to read science fiction? Science fiction writers are really creative. For example, an author might write about a time in the distant past when compasses pointed south instead of north. Actually, this idea isnt fictionits a fact! Earths magnetic poles have switched places repeatedly over the past hundreds of millions of years, each time reversing Earths magnetic field. This is illustrated in Figure 24.13. Scientists dont know for certain why magnetic reversals occur, but there is hard evidence showing that they have occurred. The evidence comes from rocks on the ocean floor. Look at Figure 24.14, which shows a ridge on the ocean floor. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. The newly hardened rock is then gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. Rock samples from many places on the ocean floor reveal that magnetic domains of rocks from different time periods are aligned in opposite directions. The evidence shows that Earths magnetic field reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. What might happen if a magnetic reversal occurred in your lifetime? How might it affect you? You can learn more about Earths magnetic reversals at this URL:  . "
The magnetosphere,(A) completely surrounds Earth (B) is found only near Earths poles (C) exists over a region larger than Earth (D) two of the above,D,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. It is a huge region that extends outward from Earth for several thousand kilometers but is strongest at the poles. You can see the extent of the magnetosphere in Figure 24.12. For an animated version of the magnetosphere, watch the video at this URL: MEDIA Click image to the left or use the URL below. URL: "
Earths magnetic field occurs only over the north and south poles.,(A) true (B) false,B,"Like a bar magnet, planet Earth has north and south magnetic poles and a magnetic field over which it exerts magnetic force. Earths magnetic field is called the magnetosphere. You can see it in the Figure 1.1. "
Earths magnetic force is exerted over a distance.,(A) true (B) false,A,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. You can see a model of the magnetosphere in the Figure 1.3. It is a huge region that extends outward from Earth in all directions. Earth exerts magnetic force over the entire field, but the force is strongest at the poles, where lines of force converge. Click image to the left or use the URL below. URL: "
Which statement about magnetic reversals is false?,(A) Magnetic reversals have occurred hundreds of times (B) The most recent magnetic reversal occurred 330 million years ago (C) There is hard evidence showing that magnetic reversals have occurred (D) Scientists do not know for certain why magnetic reversals have occurred,B,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
The idea that Earth is a magnet was first proposed,(A) by William Gilbert in 1800 (B) after seismographs were developed (C) before scientists learned about Earths inner structure (D) around the same time that Earths outer core was discovered,C,"The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. However, explaining why Earth acts like a magnet is a relatively recent discovery. It had to wait until the development of technologies such as seismographs, which detect and measure earthquake waves. Then scientists could learn about Earths inner structure (see Figure 24.15). They discovered that Earth has an inner and outer core and that the outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated by the movement of charged particles through the molten metals in the outer core. The particles move as Earth spins on its axis. The video at the URL below takes a closer look at how this occurs. MEDIA Click image to the left or use the URL below. URL: "
Many migrating birds,(A) navigate using Earths magnetic field (B) may be able to see Earths magnetic field (C) have natural compasses that they use for migration (D) all of the above,D,"There are about 10,000 living species of birds. Almost all of them can fly. Very few birds are flightless. "
about 80 north latitude,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,D,"A look on a reliable website shows us that Old Faithful Geyser is located at N44o 27 43. What does this mean? Latitude tells the distance north or south of the Equator. Latitude lines start at the Equator and circle around the planet. The North Pole is 90o N, with 90 degree lines in the Northern Hemisphere. Old Faithful is at 44 degrees, 27 minutes and 43 seconds north of the Equator. Thats just about exactly half way between the Equator and the North Pole! "
solid sphere that makes up Earths center,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,G,"The dense, iron core forms the center of the Earth. Scientists know that the core is metal from studying metallic meteorites and the Earths density. Seismic waves show that the outer core is liquid, while the inner core is solid. Movement within Earths outer liquid iron core creates Earths magnetic field. These convection currents form in the outer core because the base of the outer core is heated by the even hotter inner core. "
exactly 90 north latitude,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,B,"A look on a reliable website shows us that Old Faithful Geyser is located at N44o 27 43. What does this mean? Latitude tells the distance north or south of the Equator. Latitude lines start at the Equator and circle around the planet. The North Pole is 90o N, with 90 degree lines in the Northern Hemisphere. Old Faithful is at 44 degrees, 27 minutes and 43 seconds north of the Equator. Thats just about exactly half way between the Equator and the North Pole! "
region deep inside Earth that consists of liquid metals,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,C,"The dense, iron core forms the center of the Earth. Scientists know that the core is metal from studying metallic meteorites and the Earths density. Seismic waves show that the outer core is liquid, while the inner core is solid. Movement within Earths outer liquid iron core creates Earths magnetic field. These convection currents form in the outer core because the base of the outer core is heated by the even hotter inner core. "
Earths magnetic field,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,A,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
switching of Earths north and south magnetic poles,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,E,"Indeed, scientists discovered something astonishing. Many times in Earths history, the magnetic poles have switched positions. North becomes south and south becomes north! When the north and south poles are aligned as they are now, geologists say it is normal polarity. When they are in the opposite position, they say that it is reversed polarity. "
navigation device that always points north,(A) magnetosphere (B) north geographic pole (C) outer core (D) north magnetic pole (E) magnetic reversal (F) compass (G) inner core,F,"When an object is moving, it is not enough to describe its location. We also need to know direction. Direction is important for describing moving objects. For example, a wind blows a storm over your school. Where is that storm coming from? Where is it going? The most common way to describe direction is by using a compass. A compass is a device with a floating needle (Figure 2.1). The needle is a small magnet that aligns itself with the Earths magnetic field. The compass needle always points to magnetic north. If you have a compass and you find north, you can then know any other direction. See the directions, such as east, south, west, etc., on a compass rose. A compass needle lines up with Earths magnetic north pole. This is different from Earths geographic north pole, or true north. The geographic north pole is the top of the imaginary axis around which Earth rotates. The geographic north pole is much like the spindle of a spinning top. The location of the geographic north pole does not change. However, the magnetic north pole shifts in location over time. Depending on where you live, you can correct for the difference between the two poles when you use a map and a compass (Figure 2.2). Some maps have a double compass rose. This allows users to make the corrections between magnetic north and true north. An example is a nautical chart that boaters use to chart their positions at sea (Figure 2.3). "
homogeneous mixture in which particles are too small to be seen,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,E,"Mixtures have different properties depending on the size of their particles. Three types of mixtures based on particle size are solutions, suspensions, and colloids, all of which are described in Table 1.1. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL:  Type of Mixture Solutions Description A solution is a homogeneous mixture with tiny parti- cles. The particles are too small to see and also too small to settle or be filtered out of the mixture. When the salt is thoroughly mixed into the water in this glass, it will form a solution. The salt will no longer be visible in the water, and it wont settle to the bottom of the glass. Colloids A colloid is a homogeneous mixture with medium- sized particles. The particles are large enough to see but not large enough to settle or be filtered out of the mixture. The gelatin in this dish is a colloid. It looks red because you can see the red gelatin particles in the mixture. However, the particles are too small to settle to the bottom of the dish. A suspension is a heterogeneous mixture with large particles. The particles are large enough to see and also to settle or be filtered out of the mixture. The salad dressing in this bottle is a suspension. It contains oil, vinegar, herbs, and spices. If the bottle sits undisturbed for very long, the mixture will separate into its component parts. Thats why you should shake it before you use it. Suspensions Q: If you buy a can of paint at a paint store, a store employee may put the can on a shaker machine to mix up the paint in the can. What type of mixture is the paint? A: The paint is a suspension. Some of the components of the paint settle out of the mixture when it sits undisturbed for a long time. This explains why you need to shake (or stir) the paint before you use it. Q: The milk you buy in the supermarket has gone through a process called homogenization. This process breaks up the cream in the milk into smaller particles. As a result, the cream doesnt separate out of the milk no matter how long it sits on the shelf. Which type of mixture is homogenized milk? A: Homogenized milk is a colloid. The particles in the milk are large enough to seethats why milk is white instead of clear like water, which is the main component of milk. However, the particles are not large enough to settle out of the mixture. "
The most common element in Earths crust is,(A) water (B) iron (C) hydrogen (D) oxygen,D,An element is a pure substance. It cannot be separated into any other substances. There are more than 90 different elements that occur in nature. Some are much more common than others. Hydrogen is the most common element in the universe. Oxygen is the most common element in Earths crust. Figure 3.7 shows other examples of elements. Still others are described in the video below. MEDIA Click image to the left or use the URL below. URL: 
combination of two or more substances in any proportions,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,D,"Not all combined substances are compounds. Some are mixtures. A mixture is a combination of two or more substances in any proportion. The substances in a mixture may be elements or compounds. The substances dont combine chemically to form a new substance, as they do in a compound. Instead, they keep their original properties and just intermix. Examples of mixtures include salt and water in the ocean and gases in the atmosphere. Other examples are pictured in Figure 3.12. "
The smallest particle of an element that still has the elements properties is a(n),(A) crystal (B) compound (C) atom (D) molecule,C,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
homogeneous mixture in which particles are big enough to reflect light,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,A,"Mixtures have different properties depending on the size of their particles. Three types of mixtures based on particle size are described below. Figure 3.13 shows examples of each type. You can watch videos about the three types of mixtures at these links: MEDIA Click image to the left or use the URL below. URL:  MEDIA Click image to the left or use the URL below. URL:  A solution is a homogeneous mixture with tiny particles. An example is salt water. The particles of a solution are too small to reflect light. As a result, you cannot see them. Thats why salt water looks the same as pure water. The particles of solutions are also too small to settle or be filtered out of the mixture. A suspension is a heterogeneous mixture with large particles. An example is muddy water. The particles of a suspension are big enough to reflect light, so you can see them. They are also big enough to settle or be filtered out. Anything that you have to shake before using, such as salad dressing, is usually a suspension. A colloid is a homogeneous mixture with medium-sized particles. Examples include homogenized milk and gelatin. The particles of a colloid are large enough to reflect light, so you can see them. But they are too small to settle or filter out of the mixture. "
"Aristotle thought there were four elements, including",(A) air (B) earth (C) water (D) all of the above,D,"For thousands of years, people have wondered about the substances that make up matter. About 2500 years ago, the Greek philosopher Aristotle argued that all matter is made up of just four elements, which he identified as earth, air, water, and fire. He thought that different substances vary in their properties because they contain different proportions of these four elements. Aristotle had the right idea, but he was wrong about which substances are elements. Nonetheless, his four elements were accepted until just a few hundred years ago. Then scientists started discovering many of the elements with which we are familiar today. Eventually they discovered dozens of different elements. "
"Whenever elements combine physically, they form",(A) mixtures (B) solutions (C) compounds (D) suspensions,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
heterogeneous mixture,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,F,"The lemonade in the opening picture is an example of a homogeneous mixture. A homogeneous mixture has the same composition throughout. Another example of a homogeneous mixture is salt water. If you analyzed samples of ocean water in different places, you would find that the proportion of salt in each sample is the same: 3.5 percent. The rock in Figure 1.1 is an example of a heterogeneous mixture. A heterogeneous mixture varies in its composition. The black nuggets, for example, are not distributed evenly throughout the rock. "
unique substance that forms when two or more elements combine chemically,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,B,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
Which of the following is the best example of a heterogeneous mixture?,(A) raisin bran (B) milk (C) orange juice (D) water,A,"The lemonade in the opening picture is an example of a homogeneous mixture. A homogeneous mixture has the same composition throughout. Another example of a homogeneous mixture is salt water. If you analyzed samples of ocean water in different places, you would find that the proportion of salt in each sample is the same: 3.5 percent. The rock in Figure 1.1 is an example of a heterogeneous mixture. A heterogeneous mixture varies in its composition. The black nuggets, for example, are not distributed evenly throughout the rock. "
"rigid, lattice-like framework of many ions bonded together",(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,G,"Compounds like sodium chloride form structures called crystals. A crystal is a rigid framework of many ions locked together in a repeating pattern. Ions are electrically charged forms of atoms. You can see a crystal of sodium chloride in the Figure 1.3. It is made up of many sodium and chloride ions. Sodium and chlorine combine to form sodium chloride, or table salt. A sodium chloride crystal consists of many sodium ions (blue) and chloride ions (green) arranged in a rigid framework. Click image to the left or use the URL below. URL:  Compounds such as carbon dioxide and water form molecules instead of crystals. A molecule is the smallest particle of a compound that still has the compounds properties. It consists of two or more atoms bonded together. You saw models of carbon dioxide and water molecules above. "
pure substance that cannot be separated into any other substances,(A) colloid (B) compound (C) element (D) mixture (E) solution (F) suspension (G) crystal,C,"A pure substance is called an element. An element is a pure substance because it cannot be separated into any other substances. Currently, 92 different elements are known to exist in nature, although additional elements have been formed in labs. All matter consists of one or more of these elements. Some elements are very common; others are relatively rare. The most common element in the universe is hydrogen, which is part of Earths atmosphere and a component of water. The most common element in Earths atmosphere is nitrogen, and the most common element in Earths crust is oxygen. Click image to the left or use the URL below. URL: "
I am lighter than air and used to fill balloons. Which element am I?,(A) neon (B) carbon (C) oxygen (D) helium,D,"Did you ever get a birthday balloon like the one pictured 1.2? The balloon is filled with the noble gas helium. The gas is pumped from a tank into a Mylar balloon. Unlike a balloon filled with air, a balloon filled with helium needs to be weighted down so it wont float away. Q: Why does a helium balloon float away if its not weighted down? A: Helium atoms have just two protons, two neutrons, and two electrons, so they have less mass than any other atoms except hydrogen. As a result, helium is lighter than air, explaining why a helium balloon floats up into the air unless weighted down. Early incandescent light bulbs, like the one pictured in the Figure 1.3, didnt last very long. The filaments quickly burned out. Although air was pumped out of the bulb, it wasnt a complete vacuum. Oxygen in the small amount of air remaining inside the light bulb reacted with the metal filament. This corroded the filament and caused dark deposits on the glass. Filling a light bulb with argon gas prevents these problems. Thats why modern light bulbs are filled with argon. A: As a noble gas with eight electrons, argon doesnt react with the metal in the filament. This protects the filament and keeps the glass blub free of deposits. Noble gases are also used to fill the glass tubes of lighted signs like the one in the Figure 1.4. Although noble gases are chemically nonreactive, their electrons can be energized by sending an electric current through them. When this happens, the electrons jump to a higher energy level. When the electrons return to their original energy level, they give off energy as light. Different noble gases give off light of different colors. Neon gives off reddish-orange light, like the word Open in the sign below. Krypton gives off violet light and xenon gives off blue light. "
Iron and nickel are both,(A) elements (B) metals (C) compounds (D) two of the above,D,"Each element has a unique set of properties that make it different from all other elements. As a result, elements can be identified by their properties. For example, the elements iron and nickel are both metals that are good conductors of heat and electricity. However, iron is attracted by a magnet, whereas nickel is not. How could you use this property to separate iron objects from nickel objects? "
Which statement is false about the atoms of a given element?,(A) They are all alike (B) They are the same as the atoms of all other elements (C) They have properties of the given element (D) They all have the same structure,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
Atoms of the same element are all alike.,(A) true (B) false,A,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
John Dalton made all the following contributions to our knowledge of atoms except,(A) doing research to show atoms exist (B) introducing modern ideas about atoms (C) developing a theory of the atom (D) arguing that atoms do not exist,D,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
Each compound has a unique set of properties.,(A) true (B) false,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
Which drink is an example of a compound?,(A) lemonade (B) ice tea (C) vanilla milkshake (D) water,D,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
An example of a heterogeneous mixture is,(A) salt water (B) gelatin (C) milk (D) trail mix,D,"The lemonade in the opening picture is an example of a homogeneous mixture. A homogeneous mixture has the same composition throughout. Another example of a homogeneous mixture is salt water. If you analyzed samples of ocean water in different places, you would find that the proportion of salt in each sample is the same: 3.5 percent. The rock in Figure 1.1 is an example of a heterogeneous mixture. A heterogeneous mixture varies in its composition. The black nuggets, for example, are not distributed evenly throughout the rock. "
Atoms can be seen with a hand lens.,(A) true (B) false,B,"Unlike LEGO bricks, atoms are extremely small. The radius of an atom is well under 1 nanometer. Thats one- billionth of a meter. Such a number is hard to imagine. Consider this: trillions of atoms would fit inside the period at the end of this sentence. In other words, atoms are way too small to be seen with the naked eye. "
Which mixture has the largest particles?,(A) muddy water (B) salt water (C) milk (D) lemonade,A,"Mixtures have different properties depending on the size of their particles. Three types of mixtures based on particle size are solutions, suspensions, and colloids, all of which are described in Table 1.1. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL:  Type of Mixture Solutions Description A solution is a homogeneous mixture with tiny parti- cles. The particles are too small to see and also too small to settle or be filtered out of the mixture. When the salt is thoroughly mixed into the water in this glass, it will form a solution. The salt will no longer be visible in the water, and it wont settle to the bottom of the glass. Colloids A colloid is a homogeneous mixture with medium- sized particles. The particles are large enough to see but not large enough to settle or be filtered out of the mixture. The gelatin in this dish is a colloid. It looks red because you can see the red gelatin particles in the mixture. However, the particles are too small to settle to the bottom of the dish. A suspension is a heterogeneous mixture with large particles. The particles are large enough to see and also to settle or be filtered out of the mixture. The salad dressing in this bottle is a suspension. It contains oil, vinegar, herbs, and spices. If the bottle sits undisturbed for very long, the mixture will separate into its component parts. Thats why you should shake it before you use it. Suspensions Q: If you buy a can of paint at a paint store, a store employee may put the can on a shaker machine to mix up the paint in the can. What type of mixture is the paint? A: The paint is a suspension. Some of the components of the paint settle out of the mixture when it sits undisturbed for a long time. This explains why you need to shake (or stir) the paint before you use it. Q: The milk you buy in the supermarket has gone through a process called homogenization. This process breaks up the cream in the milk into smaller particles. As a result, the cream doesnt separate out of the milk no matter how long it sits on the shelf. Which type of mixture is homogenized milk? A: Homogenized milk is a colloid. The particles in the milk are large enough to seethats why milk is white instead of clear like water, which is the main component of milk. However, the particles are not large enough to settle out of the mixture. "
There are millions of different elements in the universe.,(A) true (B) false,B,All known matter can be divided into a little more than 100 different substances called elements. 
A crystal consists of molecules that are bonded together.,(A) true (B) false,B,"The smallest particle of a compound that still has the compounds properties is a molecule. A molecule consists of two or more atoms that are joined together. For example, a molecule of water consists of two hydrogen atoms joined to one oxygen atom (see Figure 3.10). You can learn more about molecules at this link:  Some compounds form crystals instead of molecules. A crystal is a rigid, lattice-like framework of many atoms bonded together. Table salt is an example of a compound that forms crystals (see Figure 3.11). Its crystals are made up of many sodium and chloride ions. Ions are electrically charged forms of atoms. You can actually watch crystals forming in this video:  . "
Each element has a unique set of properties.,(A) true (B) false,A,"Each element has a unique set of properties that make it different from all other elements. As a result, elements can be identified by their properties. For example, the elements iron and nickel are both metals that are good conductors of heat and electricity. However, iron is attracted by a magnet, whereas nickel is not. How could you use this property to separate iron objects from nickel objects? "
The idea of elements was first introduced by John Dalton.,(A) true (B) false,B,"Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. "
Most elements are found in compounds.,(A) true (B) false,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
A compound has the same properties as the substances it contains.,(A) true (B) false,B,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
A molecule consists of two or more atoms.,(A) true (B) false,A,A molecule is the smallest unit of a chemical compound. A compound is a substance made of two or more elements. The elements in a chemical compound are always present in a certain ratio. Water is probably one of the simplest compounds that you know. A water molecule is made of two hydrogen atoms and one oxygen atom (Figure 3.2). All water molecules have the same ratio: two hydrogen atoms to one oxygen atom. 
Table salt is an example of a compound that forms molecules.,(A) true (B) false,B,"The smallest particle of a compound that still has the compounds properties is a molecule. A molecule consists of two or more atoms that are joined together. For example, a molecule of water consists of two hydrogen atoms joined to one oxygen atom (see Figure 3.10). You can learn more about molecules at this link:  Some compounds form crystals instead of molecules. A crystal is a rigid, lattice-like framework of many atoms bonded together. Table salt is an example of a compound that forms crystals (see Figure 3.11). Its crystals are made up of many sodium and chloride ions. Ions are electrically charged forms of atoms. You can actually watch crystals forming in this video:  . "
The substances in a mixture may be elements or compounds.,(A) true (B) false,A,"Not all combined substances are compounds. Some are mixtures. A mixture is a combination of two or more substances in any proportion. The substances in a mixture may be elements or compounds. The substances dont combine chemically to form a new substance, as they do in a compound. Instead, they keep their original properties and just intermix. Examples of mixtures include salt and water in the ocean and gases in the atmosphere. Other examples are pictured in Figure 3.12. "
A package of mixed seeds is a homogeneous mixture.,(A) true (B) false,B,"Some mixtures are homogeneous. This means they have the same composition throughout. An example is salt water in the ocean. Ocean water everywhere is about 3.5 percent salt. Some mixtures are heterogeneous. This means they vary in their composition. An example is trail mix. No two samples of trail mix, even from the same package, are likely to be exactly the same. One sample might have more raisins, another might have more nuts. "
Mixtures are classified on the basis of particle size.,(A) true (B) false,A,"Mixtures have different properties depending on the size of their particles. Three types of mixtures based on particle size are solutions, suspensions, and colloids, all of which are described in Table 1.1. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL:  Type of Mixture Solutions Description A solution is a homogeneous mixture with tiny parti- cles. The particles are too small to see and also too small to settle or be filtered out of the mixture. When the salt is thoroughly mixed into the water in this glass, it will form a solution. The salt will no longer be visible in the water, and it wont settle to the bottom of the glass. Colloids A colloid is a homogeneous mixture with medium- sized particles. The particles are large enough to see but not large enough to settle or be filtered out of the mixture. The gelatin in this dish is a colloid. It looks red because you can see the red gelatin particles in the mixture. However, the particles are too small to settle to the bottom of the dish. A suspension is a heterogeneous mixture with large particles. The particles are large enough to see and also to settle or be filtered out of the mixture. The salad dressing in this bottle is a suspension. It contains oil, vinegar, herbs, and spices. If the bottle sits undisturbed for very long, the mixture will separate into its component parts. Thats why you should shake it before you use it. Suspensions Q: If you buy a can of paint at a paint store, a store employee may put the can on a shaker machine to mix up the paint in the can. What type of mixture is the paint? A: The paint is a suspension. Some of the components of the paint settle out of the mixture when it sits undisturbed for a long time. This explains why you need to shake (or stir) the paint before you use it. Q: The milk you buy in the supermarket has gone through a process called homogenization. This process breaks up the cream in the milk into smaller particles. As a result, the cream doesnt separate out of the milk no matter how long it sits on the shelf. Which type of mixture is homogenized milk? A: Homogenized milk is a colloid. The particles in the milk are large enough to seethats why milk is white instead of clear like water, which is the main component of milk. However, the particles are not large enough to settle out of the mixture. "
Components of mixtures rarely can be separated.,(A) true (B) false,B,"Not all combined substances are compounds. Some are mixtures. A mixture is a combination of two or more substances in any proportion. The substances in a mixture may be elements or compounds. The substances dont combine chemically to form a new substance, as they do in a compound. Instead, they keep their original properties and just intermix. Examples of mixtures include salt and water in the ocean and gases in the atmosphere. Other examples are pictured in Figure 3.12. "
electrically neutral atomic particle inside the nucleus of an atom,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,D,"A neutron is a particle inside the nucleus of an atom. It has no electric charge. Atoms of an element often have the same number of neutrons as protons. For example, most carbon atoms have six neutrons as well as six protons. This is also shown in Figure below . "
The smallest particles of an element that still have the elements properties are,(A) quarks (B) gluons (C) protons (D) atoms,D,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
atom that differs in its number of neutrons from other atoms of the same element,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,C,"All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their numbers of neutrons are called isotopes. Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same physical and chemical properties. Thats because they have the same numbers of protons and electrons. Click image to the left or use the URL below. URL: "
Which statement is true about the nucleus of an atom?,(A) It makes up most of the atoms volume (B) It makes up most of the atoms mass (C) It contains protons and electrons (D) It is neutral in electric charge,B,"The nucleus (plural, nuclei) is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge. Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it. The Figure 1.1 shows these parts of the atom. "
negatively charged atomic particle that moves around the nucleus of an atom,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,A,"Unlike protons and neutrons, which are located inside the nucleus at the center of the atom, electrons are found outside the nucleus. Because opposite electric charges attract each other, negative electrons are attracted to the positive nucleus. This force of attraction keeps electrons constantly moving through the otherwise empty space around the nucleus. The Figure shown 1.1 is a common way to represent the structure of an atom. It shows the electron as a particle orbiting the nucleus, similar to the way that planets orbit the sun. "
The strong force explains why,(A) electrons are attracted to the nucleus (B) the nucleus does not fly apart (C) electrons are smaller than protons (D) none of the above,B,"The strong nuclear force is a force of attraction between fundamental particles called quarks, which have a type of charge called color charge. The strong nuclear force is transferred between quarks by fundamental force-carrying particles called gluons. Both protons and neutrons consist of quarks. The exchange of gluons holds quarks together within a proton or neutron. Excess, or residual, strong force holds together protons and neutrons in the nucleus. The strong nuclear force is strong enough to overcome the electromagnetic force of repulsion pushing protons apart. Both forces are represented in the Figure 1.2. The strong nuclear force works only over very short distances. As a result, it isnt effective if the nucleus gets too big. As more protons are added to the nucleus, the electromagnetic force of repulsion between them gets stronger, while the strong nuclear force of attraction between them gets weaker. This puts an upper limit on the number of protons an atom can have and remain stable. If atoms have more than 83 protons, the electromagnetic repulsion between them is greater than the strong nuclear force of attraction between them. This makes the nucleus unstable, or radioactive, so it breaks down. The following video discusses the strong nuclear force and its role in the atom. The types of quarks found in protons and neutrons are called up quarks (u) and down quarks (d). Each proton consists of two up quarks and one down quark (uud), and each neutron consists of one up quark and two down quarks (udd). This diagram represents two protons. Click image to the left or use the URL below. URL: "
The mass number of an atom is its number of,(A) electrons (B) protons (C) neutrons (D) protons plus neutrons,D,"Electrons have almost no mass. Instead, almost all the mass of an atom is in its protons and neutrons in the nucleus. The nucleus is very small, but it is densely packed with matter. The SI unit for the mass of an atom is the atomic mass unit (amu). One atomic mass unit equals the mass of a proton, which is about 1.7  10 24 g. Each neutron also has a mass of 1 amu. Therefore, the sum of the protons and neutrons in an atom is about equal to the atoms total mass in atomic mass units. Two numbers are commonly used to distinguish atoms: atomic number and mass number. Figure 5.4 shows how these numbers are usually written. The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Problem Solving Problem: An atom has an atomic number of 12 and a mass number of 24. How many protons and neutrons does the atom have? Solution: The number of protons is the same as the atomic number, or 12. The number of neutrons is equal to the mass number minus the atomic number, or 24 12 = 12. You Try It! Problem: An atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have? What is the atoms mass in atomic mass units? "
positively charged atomic particle inside the nucleus of an atom,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,F,"The nucleus (plural, nuclei) is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge. Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it. The Figure 1.1 shows these parts of the atom. "
type of particle that makes up protons and neutrons,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,G,"A neutron is one of three main particles that make up the atom. The other two particles are the proton and electron. Atoms of all elementsexcept for most atoms of hydrogenhave neutrons in their nucleus. The nucleus is the small, dense region at the center of an atom where protons are also found. Atoms generally have about the same number of neutrons as protons. For example, all carbon atoms have six protons and most also have six neutrons. A model of a carbon atom is shown in the Figure 1.1. Click image to the left or use the URL below. URL: "
"When a fluorine atom gains an electron, it becomes a(n)",(A) positive ion (B) isotope (C) cation (D) anion,D,"Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions. Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine (see Figure 1.1). A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1. "
charged particle that forms when atom gains or loses electron(s),(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,B,"The girl pictured above became negatively charged because electrons flowed from the van de Graaff generator to her. Whenever electrons are transferred between objects, neutral matter becomes charged. This occurs even with individual atoms. Atoms are neutral in electric charge because they have the same number of negative electrons as positive protons. However, if atoms lose or gain electrons, they become charged particles called ions. You can see how this happens in the Figure 1.1. When an atom loses electrons, it becomes a positively charged ion, or cation. When an atom gains electrons, it becomes a negative charged ion, or anion. "
tiny region at the center of an atom that contains protons and neutrons,(A) electron (B) ion (C) isotope (D) neutron (E) nucleus (F) proton (G) quark,E,"The nucleus (plural, nuclei) is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge. Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it. The Figure 1.1 shows these parts of the atom. "
All protons are exactly the same.,(A) true (B) false,A,"All protons are identical. For example, hydrogen protons are exactly the same as protons of helium and all other elements, or pure substances. However, atoms of different elements have different numbers of protons. In fact, atoms of any given element have a unique number of protons that is different from the numbers of protons of all other elements. For example, a hydrogen atom has just one proton, whereas a helium atom has two protons. The number of protons in an atom determines the electrical charge of the nucleus. The nucleus also contains neutrons, but they are neutral in charge. The one proton in a hydrogen nucleus, for example, gives it a charge of +1, and the two protons in a helium nucleus give it a charge of +2. "
Electrons have the same mass as protons.,(A) true (B) false,B,"Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges cancel out, making atoms electrically neutral. "
Atoms may be positive or negative in charge.,(A) true (B) false,B,"Atoms are neutral in electric charge because they have the same number of electrons as protons. However, atoms may transfer electrons and become charged ions, as illustrated in Figure 23.5. Positively charged ions, or cations, form when atoms give up electrons. Negatively charged ions, or anions, form when atoms gain electrons. Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons either between two materials or within a material. Three ways this can occur are friction, conduction, and polarization. In all cases, the total charge remains the same. Electrons move, but they arent destroyed. This is the law of conservation of charge. "
All atoms of a given element have the same number of electrons.,(A) true (B) false,A,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
There are three quarks in each neutron.,(A) true (B) false,A,Remember the quarks from the first page of this chapter? Quarks are even tinier particles of matter that make up protons and neutrons. There are three quarks in each proton and three quarks in each neutron. The charges of quarks are balanced exactly right to give a positive charge to a proton and a neutral charge to a neutron. It might seem strange that quarks are never found alone but only as components of other particles. This is because the quarks are held together by very strange particles called gluons. 
Atoms are the smallest particles of matter.,(A) true (B) false,B,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
An atom always has the same number of electrons as neutrons.,(A) true (B) false,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
The nucleus is at the center of the atom.,(A) true (B) false,A,"The nucleus (plural, nuclei) is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge. Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it. The Figure 1.1 shows these parts of the atom. "
Atoms have no electric charge.,(A) true (B) false,A,"Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges cancel out, making atoms electrically neutral. "
The strong force keeps electrons moving around the nucleus.,(A) true (B) false,B,"When it comes to atomic particles, opposites attract. Negative electrons are attracted to positive protons. This force of attraction keeps the electrons moving about the nucleus. An analogy is the way planets orbit the sun. What about particles with the same charge, such as protons in the nucleus? They push apart, or repel, each other. So why doesnt the nucleus fly apart? The reason is a force of attraction between protons and neutrons called the strong force. The name of the strong force suits it. It is stronger than the electric force pushing protons apart. However, the strong force affects only nearby particles (see Figure 5.3). It is not effective if the nucleus gets too big. This puts an upper limit on the number of protons an atom can have and remain stable. You can learn more about atomic forces in the colorful tutorial at this URL:  . "
Electrons have almost no mass.,(A) true (B) false,A,"Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges cancel out, making atoms electrically neutral. "
The mass of an atom equals the sum of its protons and neutrons.,(A) true (B) false,A,"Electrons have almost no mass. Instead, almost all the mass of an atom is in its protons and neutrons in the nucleus. The nucleus is very small, but it is densely packed with matter. The SI unit for the mass of an atom is the atomic mass unit (amu). One atomic mass unit equals the mass of a proton, which is about 1.7  10 24 g. Each neutron also has a mass of 1 amu. Therefore, the sum of the protons and neutrons in an atom is about equal to the atoms total mass in atomic mass units. Two numbers are commonly used to distinguish atoms: atomic number and mass number. Figure 5.4 shows how these numbers are usually written. The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Problem Solving Problem: An atom has an atomic number of 12 and a mass number of 24. How many protons and neutrons does the atom have? Solution: The number of protons is the same as the atomic number, or 12. The number of neutrons is equal to the mass number minus the atomic number, or 24 12 = 12. You Try It! Problem: An atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have? What is the atoms mass in atomic mass units? "
"For most elements, isotopes are named for their atomic number.",(A) true (B) false,B,"For most elements other than hydrogen, isotopes are named for their mass number. For example, carbon atoms with the usual 6 neutrons have a mass number of 12 (6 protons + 6 neutrons = 12), so they are called carbon-12. Carbon atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms are the isotope called carbon-13. Q: Some carbon atoms have 8 neutrons. What is the name of this isotope of carbon? A: Carbon atoms with 8 neutrons have an atomic mass of 14 (6 protons + 8 neutrons = 14), so this isotope of carbon is named carbon-14. "
Each proton consists of three quarks.,(A) true (B) false,A,Remember the quarks from the first page of this chapter? Quarks are even tinier particles of matter that make up protons and neutrons. There are three quarks in each proton and three quarks in each neutron. The charges of quarks are balanced exactly right to give a positive charge to a proton and a neutral charge to a neutron. It might seem strange that quarks are never found alone but only as components of other particles. This is because the quarks are held together by very strange particles called gluons. 
Quarks are held together by gluons.,(A) true (B) false,A,"Gluons make quarks attract each other more strongly the farther apart the quarks get. To understand how gluons work, imagine holding a rubber band between your fingers. If you try to move your hands apart, they will be pulled back together by the rubber band. The farther apart you move your hands, the stronger the force of the rubber band pulling your hands together. Gluons work the same way on quarks inside protons and neutrons (and other, really rare particles too). If you were to move your hands apart with enough force, the rubber band holding them together would break. The same is true of quarks. If they are given enough energy, they pull apart with enough force to ""break"" the binding from the gluons. However, all the energy that is put into a particle to make this possible is then used to create a new set of quarks and gluons. And so a new proton or neutron appears. "
"If an atom were the size of a football stadium, the nucleus would be about the size of a",(A) microwave oven (B) basketball (C) pea (D) car,C,"The nucleus of the atom is extremely small. Its radius is only about 1/100,000 of the total radius of the atom. If an atom were the size of a football stadium, the nucleus would be about the size of a pea! Click image to the left or use the URL below. URL:  Electrons have virtually no mass, but protons and neutrons have a lot of mass for their size. As a result, the nucleus has virtually all the mass of an atom. Given its great mass and tiny size, the nucleus is very dense. If an object the size of a penny had the same density as the nucleus of an atom, its mass would be greater than 30 million tons! Click image to the left or use the URL below. URL: "
The number of protons in atoms is,(A) the same for all atoms (B) unique for each element (C) always equal to the number of neutrons (D) none of the above,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
The strong force,(A) affects only nearby particles (B) is stronger than electric force (C) is not effective if the nucleus is too big (D) all of the above,D,"The strong nuclear force is a force of attraction between fundamental particles called quarks, which have a type of charge called color charge. The strong nuclear force is transferred between quarks by fundamental force-carrying particles called gluons. Both protons and neutrons consist of quarks. The exchange of gluons holds quarks together within a proton or neutron. Excess, or residual, strong force holds together protons and neutrons in the nucleus. The strong nuclear force is strong enough to overcome the electromagnetic force of repulsion pushing protons apart. Both forces are represented in the Figure 1.2. The strong nuclear force works only over very short distances. As a result, it isnt effective if the nucleus gets too big. As more protons are added to the nucleus, the electromagnetic force of repulsion between them gets stronger, while the strong nuclear force of attraction between them gets weaker. This puts an upper limit on the number of protons an atom can have and remain stable. If atoms have more than 83 protons, the electromagnetic repulsion between them is greater than the strong nuclear force of attraction between them. This makes the nucleus unstable, or radioactive, so it breaks down. The following video discusses the strong nuclear force and its role in the atom. The types of quarks found in protons and neutrons are called up quarks (u) and down quarks (d). Each proton consists of two up quarks and one down quark (uud), and each neutron consists of one up quark and two down quarks (udd). This diagram represents two protons. Click image to the left or use the URL below. URL: "
A neutron has the same mass as a(n),(A) nucleus (B) electron (C) proton (D) quark,C,"Unlike protons and electrons, which are electrically charged, neutrons have no charge. In other words, they are electrically neutral. Thats why the neutrons in the diagram above are labeled n0 . The zero stands for zero charge. The mass of a neutron is slightly greater than the mass of a proton, which is 1 atomic mass unit (amu). (An atomic mass unit equals about 1.67  1027 kilograms.) A neutron also has about the same diameter as a proton, or 1.7 1017 meters. "
"A nitrogen atom has an atomic number of 7 and a mass number of 14. How many protons, neutrons, and electrons does it have?",(A) 7 protons (B) 14 neutrons (C) 7 electrons (D) b 14 protons (E) 7 neutrons (F) 7 electrons (G) c 7 protons (H) 7 neutrons (I) 7 electrons (J) d 7 protons (K) 7 neutrons (L) 14 electrons,C,"Electrons have almost no mass. Instead, almost all the mass of an atom is in its protons and neutrons in the nucleus. The nucleus is very small, but it is densely packed with matter. The SI unit for the mass of an atom is the atomic mass unit (amu). One atomic mass unit equals the mass of a proton, which is about 1.7  10 24 g. Each neutron also has a mass of 1 amu. Therefore, the sum of the protons and neutrons in an atom is about equal to the atoms total mass in atomic mass units. Two numbers are commonly used to distinguish atoms: atomic number and mass number. Figure 5.4 shows how these numbers are usually written. The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Problem Solving Problem: An atom has an atomic number of 12 and a mass number of 24. How many protons and neutrons does the atom have? Solution: The number of protons is the same as the atomic number, or 12. The number of neutrons is equal to the mass number minus the atomic number, or 24 12 = 12. You Try It! Problem: An atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have? What is the atoms mass in atomic mass units? "
"If an atom loses electrons, it becomes a(n)",(A) isotope (B) cation (C) anion (D) gluon,B,"Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions. Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine (see Figure 1.1). A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1. "
How many neutrons are there in the most common isotope of hydrogen?,(A) zero (B) one (C) two (D) three,A,"Hydrogen is an example of an element that has isotopes. Three isotopes of hydrogen are modeled in the Figure hydrogen. Some hydrogen atoms have one neutron as well. These atoms are the isotope named deuterium. Other hydrogen atoms have two neutrons. These atoms are the isotope named tritium. Q: The mass number of an atom is the sum of its protons and neutrons. What is the mass number of each isotope of hydrogen shown above? A: The mass numbers are: hydrogen = 1, deuterium = 2, and tritium = 3. "
Which statement is not part of the original atomic theory?,(A) Atoms consist of smaller particles of matter (B) Atoms cannot be created or destroyed (C) All atoms of the same element have the same mass (D) Atoms join together to form compounds,A,The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. 
John Dalton thought that an atom is like a(n),(A) plum pudding (B) solar system (C) hard solid ball (D) vacuum tube,C,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
The scientist who discovered protons was,(A) John Dalton (B) J (C) Ernest Rutherford (D) James Chadwick,C,"Based on his results, Rutherford concluded that all the positive charge of an atom is concentrated in a small central area. He called this area the nucleus. Rutherford later discovered that the nucleus contains positively charged particles. He named the positive particles protons. Rutherford also predicted the existence of neutrons in the nucleus. However, he failed to find them. One of his students, a physicist named James Chadwick, went on to discover neutrons in 1932. You learn how at this URL:  . "
Aristotle thought that,(A) atoms exist (B) atoms are uncuttable (C) all matter consists of atoms (D) the idea of atoms is ridiculous,D,"A Greek philosopher named Thales, who lived around 600 BCE, has been called the father of science for his ideas about the natural world. He proposed that natural events such as lightning and earthquakes have natural causes. Up until then, people understood such events to be the acts of gods or other supernatural forces. Q: Why was Thales idea about natural causes such an important contribution to science? A: Natural causes can be investigated and understood, whereas gods or other supernatural causes are above nature and not suitable for investigation. Just a few hundred years after Thales, the Greek philosopher Aristotle made a very important contribution to science. You can see what Aristotle looked like in the Figure 1.1. Prior to Aristotle, other philosophers believed that they could find the truth about the natural world by inward reflectionin other words, just by thinking about it. Aristotle, in contrast, thought that truth about the natural world could come only from observations of nature and inductive reasoning. He argued that knowledge of nature must be based on evidence and logic. This idea is called empiricism, and it is the basis of science today. Aristotle introduced the idea of empiricism around 350 BCE. It is a hallmark of modern science. "
Rutherford concluded from his experiments that,(A) all the positive charge of an atom is concentrated in the center (B) positive charge is spread evenly throughout an atom (C) electrons orbit the positively charged nucleus (D) two of the above,D,"Rutherford made the same inferences. He concluded that all of the positive charge and virtually all of the mass of an atom are concentrated in one tiny area and the rest of the atom is mostly empty space. Rutherford called the area of concentrated positive charge the nucleus. He predictedand soon discoveredthat the nucleus contains positively charged particles, which he named protons. Rutherford also predicted the existence of neutral nuclear particles called neutrons, but he failed to find them. However, his student James Chadwick discovered them several years later. "
scientist who discovered electrons.,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,D,The next major advance in the history of the atom was the discovery of electrons. These were the first subatomic particles to be identified. They were discovered in 1897 by a British physicist named J. J. Thomson. You can learn more about Thomson and his discovery at this online exhibit:  . 
philosopher who thought the idea of the atom was ridiculous,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,B,"Democritus was an important philosopher, but he was less influential than another Greek philosopher named Aristo- tle, who lived about 100 years after Democritus. Aristotle rejected Democritus idea of the atom. In fact, Aristotle thought the idea was ridiculous. Unfortunately, Aristotles opinion was accepted for more than 2000 years, and Democritus idea was more or less forgotten. However, the idea of the atom was revived around 1800 by the English scientist John Dalton. Dalton developed an entire theory about the atom, much of which is still accepted today. He based his theory on experimental evidence, not on lucky guesses. "
Thomsons atomic model,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,F,"Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is called the plum pudding model. You can see it in Figure 5.11. It shows the atom as a sphere of positive charge (the pudding) with negative electrons (the plums) scattered through it. "
Thomson aimed a beam of alpha particles at gold foil.,(A) true (B) false,B,"In 1899, Rutherford discovered that some elements give off positively charged particles. He named them alpha particles (a). In 1911, he used alpha particles to study atoms. He aimed a beam of alpha particles at a very thin sheet of gold foil. Outside the foil, he placed a screen of material that glowed when alpha particles struck it. If Thomsons plum pudding model were correct, the alpha particles should be deflected a little as they passed through the foil. Why? The positive ""pudding"" part of gold atoms would slightly repel the positive alpha particles. This would cause the alpha particles to change course. But Rutherford got a surprise. Most of the alpha particles passed straight through the foil as though they were moving through empty space. Even more surprising, a few of the alpha particles bounced back from the foil as though they had struck a wall. This is called back scattering. It happened only in very small areas at the centers of the gold atoms. "
philosopher who introduced the idea of the atom,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,A,"Democritus was an important philosopher, but he was less influential than another Greek philosopher named Aristo- tle, who lived about 100 years after Democritus. Aristotle rejected Democritus idea of the atom. In fact, Aristotle thought the idea was ridiculous. Unfortunately, Aristotles opinion was accepted for more than 2000 years, and Democritus idea was more or less forgotten. However, the idea of the atom was revived around 1800 by the English scientist John Dalton. Dalton developed an entire theory about the atom, much of which is still accepted today. He based his theory on experimental evidence, not on lucky guesses. "
The plums in the plum pudding model represent protons.,(A) true (B) false,B,"Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is called the plum pudding model. You can see it in Figure 5.11. It shows the atom as a sphere of positive charge (the pudding) with negative electrons (the plums) scattered through it. "
Rutherfords atomic model,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,G,"Rutherfords discoveries meant that Thomsons plum pudding model was incorrect. Positive charge is not spread evenly throughout an atom. Instead, it is all concentrated in the tiny nucleus. The rest of the atom is empty space except for the electrons scattered through it. In Rutherfords model of the atom, which is shown in the Figure 1.3, the electrons move around the massive nucleus like planets orbiting the sun. Thats why his model is called the planetary model. Rutherford didnt know exactly where or how electrons orbit the nucleus. That research would be undertaken by later scientists, beginning with Niels Bohr in 1913. New and improved atomic models would also be developed. Nonetheless, Rutherfords model is still often used to represent the atom. "
scientist who developed atomic theory,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,C,"Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. "
The planets in the planetary model represent electrons.,(A) true (B) false,A,"Today, these ideas about electrons are represented by the electron cloud model. The electron cloud is an area around the nucleus where electrons are likely to be. Figure 5.17 shows an electron cloud model for a helium atom. "
scientist who discovered the nucleus,(A) Democritus (B) Aristotle (C) John Dalton (D) J (E) Ernest Rutherford (F) plum pudding model (G) planetary model,E,A physicist from New Zealand named Ernest Rutherford made the next major discovery about atoms. He discovered the nucleus. You can watch a video about Rutherford and his discovery at this URL:  MEDIA Click image to the left or use the URL below. URL: 
The first subatomic particle to be discovered was the proton.,(A) true (B) false,B,"Scientists have long wanted to find the most basic building blocks of the universe. They asked, what are the fundamental particles of matter that cannot be subdivided into smaller, simpler particles, and what holds these particles together? The quest for fundamental particles began thousands of years ago. Scientists thought they had finally found them when John Dalton discovered the atom in 1803 (see the timeline in Table 1.1). The word atom means indivisible, and Dalton thought that the atom could not be divided into smaller, simpler particles. Year Discovery Year 1803 Discovery John Dalton discovers the atom. 1897 J.J. Thomson discovers the electron, the first lepton to be discovered. 1905 Albert Einstein discovers the photon, the first boson to be discovered. 1911 Ernest Rutherford discovers the proton, the first particle to be discovered in the nucleus of the atom. Year 1932 Discovery James Chadwick discovers the neutron, another particle in the nucleus. 1964 Murray Gell-Mann proposes the existence of quarks, the fundamental particles that make up protons and neutrons. 1964-present Through the research of many scientists, many other fundamental particles (except gravitons) are shown to exist. For almost 100 years after Dalton discovered atoms, they were accepted as the fundamental particles of matter. But starting in the late 1890s with the discovery of electrons, particles smaller and simpler than atoms were identified. Within a few decades, protons and neutrons were also discovered. Ultimately, hundreds of subatomic particles were found. "
Dalton thought that all substances are made of atoms.,(A) true (B) false,A,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
The history of the atom began almost,(A) 2500 years ago (B) 700 years ago (C) 500 years ago (D) 100 years ago,A,"The history of the atom begins around 450 B.C. with a Greek philosopher named Democritus (see Figure 5.7). Democritus wondered what would happen if you cut a piece of matter, such as an apple, into smaller and smaller pieces. He thought that a point would be reached where matter could not be cut into still smaller pieces. He called these ""uncuttable"" pieces atomos. This is where the modern term atom comes from. Democritus was an important philosopher. However, he was less influential than the Greek philosopher Aristotle, who lived about 100 years after Democritus. Aristotle rejected Democrituss idea of atoms. In fact, Aristotle thought "
Daltons research provided evidence that,(A) atoms exist (B) gases consist of tiny particles in constant motion (C) a compound always consists of the same elements in the same ratio (D) all of the above,D,"Dalton did many experiments that provided evidence for the existence of atoms. For example: He investigated pressure and other properties of gases, from which he inferred that gases must consist of tiny, individual particles that are in constant, random motion. He researched the properties of compounds, which are substances that consist of more than one element. He showed that a given compound is always comprised of the same elements in the same whole-number ratio and that different compounds consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of separate, discrete particles that cannot be subdivided. "
Which statement is part of Daltons atomic theory?,(A) All substances are made of atoms (B) Atoms can be divided into smaller particles (C) Atoms form when compounds join together (D) All atoms of the same element have the same number of protons,A,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
Daltons atomic models were most similar to,(A) bowling balls (B) plum puddings (C) planetary orbits (D) blades of a fan,A,"Because Dalton thought atoms were the smallest particles of matter, he envisioned them as solid, hard spheres, like billiard (pool) balls, so he used wooden balls to model them. Three of his model atoms are pictured in the Figure and used to model compounds. Q: When scientists discovered smaller particles inside the atom, they realized that Daltons atomic models were too simple. How do modern atomic models differ from Daltons models? A: Modern atomic models, like the one pictured at the top of this article, usually represent subatomic particles, including electrons, protons, and neutrons. "
Thomsons research involved,(A) gold foil and alpha particles (B) electric current and a vacuum tube (C) gases and pressure (D) neutrons and back scattering,B,"Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. "
"In the plum pudding model of the atom, the plums represent",(A) protons (B) neutrons (C) nuclei (D) electrons,D,"Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is called the plum pudding model. You can see it in Figure 5.11. It shows the atom as a sphere of positive charge (the pudding) with negative electrons (the plums) scattered through it. "
"In the planetary model, the planets represent",(A) alpha particles (B) gold atoms (C) electrons (D) positive charges,C,"The ancient Greeks thought that Earth was at the center of the universe, as shown in Figure 25.1. The sky had a set of spheres layered on top of one another. Each object in the sky was attached to one of these spheres. The object moved around Earth as that sphere rotated. These spheres contained the Moon, the Sun, and the five planets they recognized: Mercury, Venus, Mars, Jupiter, and Saturn. An outer sphere contained all the stars. The planets appear to move much faster than the stars, so the Greeks placed them closer to Earth. Ptolemy published this model of the solar system around 150 AD. "
Aristotle rejected Democrituss idea of the atom.,(A) true (B) false,A,"Democritus was an important philosopher, but he was less influential than another Greek philosopher named Aristo- tle, who lived about 100 years after Democritus. Aristotle rejected Democritus idea of the atom. In fact, Aristotle thought the idea was ridiculous. Unfortunately, Aristotles opinion was accepted for more than 2000 years, and Democritus idea was more or less forgotten. However, the idea of the atom was revived around 1800 by the English scientist John Dalton. Dalton developed an entire theory about the atom, much of which is still accepted today. He based his theory on experimental evidence, not on lucky guesses. "
Dalton thought that atoms could be created or destroyed.,(A) true (B) false,B,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
Daltons atomic theory was later completely rejected.,(A) true (B) false,B,The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. 
Ernest Rutherford discovered neutrons.,(A) true (B) false,B,A physicist from New Zealand named Ernest Rutherford made the next major discovery about atoms. He discovered the nucleus. You can watch a video about Rutherford and his discovery at this URL:  MEDIA Click image to the left or use the URL below. URL: 
Thomson showed that electric charge is carried by particles of matter.,(A) true (B) false,A,"Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. "
The pudding in the plum pudding model represents positive charge.,(A) true (B) false,A,"Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is called the plum pudding model. You can see it in Figure 5.11. It shows the atom as a sphere of positive charge (the pudding) with negative electrons (the plums) scattered through it. "
Democritus represented atoms with solid wooden balls.,(A) true (B) false,B,"Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. "
"In the gold foil experiments, most of the alpha particles were deflected backward from the gold foil.",(A) true (B) false,B,"In 1899, Rutherford discovered that some elements give off positively charged particles. He named them alpha particles (a). In 1911, he used alpha particles to study atoms. He aimed a beam of alpha particles at a very thin sheet of gold foil. Outside the foil, he placed a screen of material that glowed when alpha particles struck it. If Thomsons plum pudding model were correct, the alpha particles should be deflected a little as they passed through the foil. Why? The positive ""pudding"" part of gold atoms would slightly repel the positive alpha particles. This would cause the alpha particles to change course. But Rutherford got a surprise. Most of the alpha particles passed straight through the foil as though they were moving through empty space. Even more surprising, a few of the alpha particles bounced back from the foil as though they had struck a wall. This is called back scattering. It happened only in very small areas at the centers of the gold atoms. "
Dalton was the first scientist to observe atoms with a microscope.,(A) true (B) false,B,"Around 1800, the English chemist John Dalton brought back Democritus ancient idea of the atom. You can see a picture of Dalton 1.1. Dalton grew up in a working-class family. As an adult, he made a living by teaching and just did research in his spare time. Nonetheless, from his research he developed one of the most important theories in all of science. Based on his research results, he was able to demonstrate that atoms actually do exist, something that Democritus had only guessed. "
Electrons flow through a vacuum tube from the negative end to the positive end.,(A) true (B) false,A,"Thomson was interested in electricity. He did experiments in which he passed an electric current through a vacuum tube. The experiments are described in Figure 5.10. Thomsons experiments showed that an electric current consists of flowing, negatively charged particles. Why was this discovery important? Many scientists of Thomsons time thought that electric current consists of rays, like rays of light, and that it is positive rather than negative. Thomsons experiments also showed that the negative particles are all alike and smaller than atoms. Thomson concluded that the negative particles couldnt be fundamental units of matter because they are all alike. Instead, they must be parts of atoms. The negative particles were later named electrons. "
Which statement about energy levels is false?,(A) They are located at fixed distances from the nucleus of the atom (B) They are the only places where electrons can be found (C) They have more energy when they are farther from the nucleus (D) They all have the same number of electrons,D,"Basic to Bohrs model is the idea of energy levels. Energy levels are areas located at fixed distances from the nucleus of the atom. They are the only places where electrons can be found. Energy levels are a little like rungs on a ladder. You can stand on one rung or another but not between the rungs. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model of an atom in Figure 5.15 has six energy levels. The level with the least energy is the one closest to the nucleus. As you go farther from the nucleus, the levels have more and more energy. Electrons can jump from one energy level to another. If an atom absorbs energy, some of its electrons can jump to a higher energy level. If electrons jump to a lower energy level, the atom emits, or gives off, energy. You can see an animation at this happening at the URL below. "
What are orbitals?,(A) regions in the electron cloud where electrons are most likely to be (B) fixed paths in which electrons orbit the nucleus (C) places where electron waves are unstable (D) none of the above,A,"The atomic model above is useful for some purposes, but its too simple when it comes to the location of electrons. In reality, its impossible to say what path an electron will follow. Instead, its only possible to describe the chances of finding an electron in a certain region around the nucleus. The region where an electron is most likely to be is called an orbital. Each orbital can have at most two electrons. Some orbitals, called S orbitals, are shaped like spheres, with the nucleus in the center. An S orbital is pictured in Figure 1.2. Where the dots are denser, the chance of finding an electron is greater. Also pictured in Figure 1.2 is a P orbital. P orbitals are shaped like dumbbells, with the nucleus in the pinched part of the dumbbell. Click image to the left or use the URL below. URL:  Q: How many electrons can there be in each type of orbital shown above? A: There can be a maximum of two electrons in any orbital, regardless of its shape. Q: Where is the nucleus in each orbital? A: The nucleus is at the center of each orbital. It is in the middle of the sphere in the S orbital and in the pinched part of the P orbital. "
An electron emits energy when it jumps from,(A) a proton to a neutron (B) an electron cloud to an orbital (C) an orbital to the atomic nucleus (D) a higher energy level to a lower energy level,D,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
How many electrons can there be in energy level 1?,(A) 0 (B) 1 (C) 2 (D) 3,C,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
Bohrs model of the atom differs from Rutherfords model in the,(A) placement of the nucleus (B) charge of the nucleus (C) number of electrons (D) location of electrons,D,"Rutherfords discoveries meant that Thomsons plum pudding model was incorrect. Positive charge is not spread evenly throughout an atom. Instead, it is all concentrated in the tiny nucleus. The rest of the atom is empty space except for the electrons scattered through it. In Rutherfords model of the atom, which is shown in the Figure 1.3, the electrons move around the massive nucleus like planets orbiting the sun. Thats why his model is called the planetary model. Rutherford didnt know exactly where or how electrons orbit the nucleus. That research would be undertaken by later scientists, beginning with Niels Bohr in 1913. New and improved atomic models would also be developed. Nonetheless, Rutherfords model is still often used to represent the atom. "
Bohrs research focused on,(A) electrons (B) neutrons (C) protons (D) none of the above,A,"Bohrs research focused on electrons. In 1913, he discovered evidence that the orbits of electrons are located at fixed distances from the nucleus. Remember, Rutherford thought that electrons orbit the nucleus at random. Figure 5.14 shows Bohrs model of the atom. "
Which statement about energy levels is false?,(A) They are located at fixed distances from the nucleus (B) They are the only places where electrons can be found (C) They have more energy when they are farther from the nucleus (D) There are only two of them,D,"Basic to Bohrs model is the idea of energy levels. Energy levels are areas located at fixed distances from the nucleus of the atom. They are the only places where electrons can be found. Energy levels are a little like rungs on a ladder. You can stand on one rung or another but not between the rungs. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model of an atom in Figure 5.15 has six energy levels. The level with the least energy is the one closest to the nucleus. As you go farther from the nucleus, the levels have more and more energy. Electrons can jump from one energy level to another. If an atom absorbs energy, some of its electrons can jump to a higher energy level. If electrons jump to a lower energy level, the atom emits, or gives off, energy. You can see an animation at this happening at the URL below. "
Fireworks give off light energy when their electrons,(A) flow to different atoms (B) jump to a lower energy level (C) produce electric current (D) change from matter to energy,B,"Bohrs idea of energy levels is still useful today. It helps explain how matter behaves. For example, when chemicals in fireworks explode, their atoms absorb energy. Some of their electrons jump to a higher energy level. When the electrons move back to their original energy level, they give off the energy as light. Different chemicals have different arrangements of electrons, so they give off light of different colors. This explains the blue- and purple- colored fireworks in Figure 5.16. "
The focus of Bohrs research was the nucleus.,(A) true (B) false,B,"Bohrs research focused on electrons. In 1913, he discovered evidence that the orbits of electrons are located at fixed distances from the nucleus. Remember, Rutherford thought that electrons orbit the nucleus at random. Figure 5.14 shows Bohrs model of the atom. "
Energy levels farther from the nucleus have,(A) less energy (B) more orbitals (C) a greater maximum number of electrons (D) two of the above,D,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
Bohr rejected modern atomic theory.,(A) true (B) false,B,"Bohrs research focused on electrons. In 1913, he discovered evidence that the orbits of electrons are located at fixed distances from the nucleus. Remember, Rutherford thought that electrons orbit the nucleus at random. Figure 5.14 shows Bohrs model of the atom. "
How many orbitals are there at energy level 3?,(A) 1 (B) 4 (C) 9 (D) 16,C,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
Electrons bend around the nucleus instead of falling toward it because electrons behave like,(A) protons (B) orbitals (C) clouds (D) waves,D,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
There is a maximum of two energy levels in an atom.,(A) true (B) false,B,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
Where would you not be likely to find electrons in an atom?,(A) inside the nucleus (B) attached to the nucleus (C) between energy levels (D) all of the above,D,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
Electrons fall toward the nucleus because they behave like waves.,(A) true (B) false,B,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
Energy levels are located between the orbitals of atoms.,(A) true (B) false,B,"Basic to Bohrs model is the idea of energy levels. Energy levels are areas located at fixed distances from the nucleus of the atom. They are the only places where electrons can be found. Energy levels are a little like rungs on a ladder. You can stand on one rung or another but not between the rungs. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model of an atom in Figure 5.15 has six energy levels. The level with the least energy is the one closest to the nucleus. As you go farther from the nucleus, the levels have more and more energy. Electrons can jump from one energy level to another. If an atom absorbs energy, some of its electrons can jump to a higher energy level. If electrons jump to a lower energy level, the atom emits, or gives off, energy. You can see an animation at this happening at the URL below. "
Energy level 1 has the most energy.,(A) true (B) false,B,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
Electrons can move from one energy level to another.,(A) true (B) false,A,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
Scientists can now determine the exact location of any given electron.,(A) true (B) false,B,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
Electrons are attracted to the nucleus because of the strong force.,(A) true (B) false,B,"When it comes to atomic particles, opposites attract. Negative electrons are attracted to positive protons. This force of attraction keeps the electrons moving about the nucleus. An analogy is the way planets orbit the sun. What about particles with the same charge, such as protons in the nucleus? They push apart, or repel, each other. So why doesnt the nucleus fly apart? The reason is a force of attraction between protons and neutrons called the strong force. The name of the strong force suits it. It is stronger than the electric force pushing protons apart. However, the strong force affects only nearby particles (see Figure 5.3). It is not effective if the nucleus gets too big. This puts an upper limit on the number of protons an atom can have and remain stable. You can learn more about atomic forces in the colorful tutorial at this URL:  . "
Some regions of the electron cloud are denser than others.,(A) true (B) false,A,"Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals. Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table 5.1 lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons. Energy Level Number of Orbitals 1 2 3 4 1 4 9 16 Max. No. of Electrons (@ 2 per orbital) 2 8 18 32 Figure 5.18 shows the arrangement of electrons in an atom of magnesium as an example. The most stable arrange- ment of electrons occurs when electrons fill the orbitals at the lowest energy levels first before more are added at higher levels. You can learn more about orbitals and their electrons at the URL below: "
There is a maximum of two orbitals per energy level.,(A) true (B) false,B,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
Fireworks give off light when their electrons split in two.,(A) true (B) false,B,"Bohrs idea of energy levels is still useful today. It helps explain how matter behaves. For example, when chemicals in fireworks explode, their atoms absorb energy. Some of their electrons jump to a higher energy level. When the electrons move back to their original energy level, they give off the energy as light. Different chemicals have different arrangements of electrons, so they give off light of different colors. This explains the blue- and purple- colored fireworks in Figure 5.16. "
"Since the 1920s, physicists have known that electrons travel in fixed paths.",(A) true (B) false,B,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
Wavelike particles in the atom exist only where the wave is stable.,(A) true (B) false,A,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
All energy levels have the same maximum number of electrons.,(A) true (B) false,B,"Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals. Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table 5.1 lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons. Energy Level Number of Orbitals 1 2 3 4 1 4 9 16 Max. No. of Electrons (@ 2 per orbital) 2 8 18 32 Figure 5.18 shows the arrangement of electrons in an atom of magnesium as an example. The most stable arrange- ment of electrons occurs when electrons fill the orbitals at the lowest energy levels first before more are added at higher levels. You can learn more about orbitals and their electrons at the URL below: "
number of orbitals in the first energy level,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,G,"Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals. Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table 5.1 lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons. Energy Level Number of Orbitals 1 2 3 4 1 4 9 16 Max. No. of Electrons (@ 2 per orbital) 2 8 18 32 Figure 5.18 shows the arrangement of electrons in an atom of magnesium as an example. The most stable arrange- ment of electrons occurs when electrons fill the orbitals at the lowest energy levels first before more are added at higher levels. You can learn more about orbitals and their electrons at the URL below: "
area surrounding the nucleus of an atom where electrons are likely to be,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,A,"Today, these ideas about electrons are represented by the electron cloud model. The electron cloud is an area around the nucleus where electrons are likely to be. Figure 5.17 shows an electron cloud model for a helium atom. "
scientist who thought that electrons orbit the nucleus like planets orbit the sun,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,C,"Bohrs research focused on electrons. In 1913, he discovered evidence that the orbits of electrons are located at fixed distances from the nucleus. Remember, Rutherford thought that electrons orbit the nucleus at random. Figure 5.14 shows Bohrs model of the atom. "
maximum number of electrons per orbital,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,F,"Some regions of the electron cloud are denser than others. The denser regions are areas where electrons are most likely to be. These regions are called orbitals. Each orbital has a maximum of just two electrons. Different energy levels in the cloud have different numbers of orbitals. Therefore, different energy levels have different maximum numbers of electrons. Table 5.1 lists the number of orbitals and electrons for the first four energy levels. Energy levels farther from the nucleus have more orbitals. Therefore, these levels can hold more electrons. Energy Level Number of Orbitals 1 2 3 4 1 4 9 16 Max. No. of Electrons (@ 2 per orbital) 2 8 18 32 Figure 5.18 shows the arrangement of electrons in an atom of magnesium as an example. The most stable arrange- ment of electrons occurs when electrons fill the orbitals at the lowest energy levels first before more are added at higher levels. You can learn more about orbitals and their electrons at the URL below: "
area located at a fixed distance from the nucleus of an atom where electrons can orbit the nucleus,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,B,"Bohrs research focused on electrons. In 1913, he discovered evidence that the orbits of electrons are located at fixed distances from the nucleus. Remember, Rutherford thought that electrons orbit the nucleus at random. Figure 5.14 shows Bohrs model of the atom. "
wavelike particles that move around the nucleus of an atom,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,E,"At the center of an atom is the nucleus (plural, nuclei). The nucleus contains most of the atoms mass. However, in size, its just a tiny part of the atom. The model in Figure 5.1 is not to scale. If an atom were the size of a football stadium, the nucleus would be only about the size of a pea. The nucleus, in turn, consists of two types of particles, called protons and neutrons. These particles are tightly packed inside the nucleus. Constantly moving about the nucleus are other particles called electrons. You can see a video about all three types of atomic particles at this URL:  (1:57). "
scientist who discovered energy levels,(A) electron cloud (B) energy level (C) Rutherford (D) Bohr (E) electron (F) two (G) one,D,"Bohrs idea of energy levels is still useful today. It helps explain how matter behaves. For example, when chemicals in fireworks explode, their atoms absorb energy. Some of their electrons jump to a higher energy level. When the electrons move back to their original energy level, they give off the energy as light. Different chemicals have different arrangements of electrons, so they give off light of different colors. This explains the blue- and purple- colored fireworks in Figure 5.16. "
Mendeleev organized the elements based on their,(A) atomic number (B) number of protons (C) atomic mass (D) number of neutrons,C,"In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements. He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row. When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups. Mendeleevs table is called a periodic table and the rows are called periods. Thats because the table keeps repeating from row to row, and periodic means repeating. "
"In the modern periodic table, atomic number",(A) increases from top to bottom within each period (B) increases from left to right within each group (C) is the same within each group but not between groups (D) none of the above,D,"In the modern periodic table, elements are organized by atomic number. The atomic number is the number of protons in an atom of an element. This number is unique for each element, so it seems like an obvious way to organize the elements. (Mendeleev used atomic mass instead of atomic number because protons had not yet been discovered when he made his table.) In the modern table, atomic number increases from left to right across each period. It also increases from top to bottom within each group. How is this like Mendeleevs table? "
The shortest period in the periodic table is period,(A) 18 (B) 7 (C) 6 (D) 1,D,"Rows of the modern periodic table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements: hydrogen (H) and helium (He). In contrast, periods 6 and 7 are so long that many of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary three-letter symbols, such as Uub. The number of each period represents the number of energy levels that have electrons in them for atoms of each element in that period. Q: Find calcium (Ca) in the Figure 1.1. How many energy levels have electrons in them for atoms of calcium? A: Calcium is in period 4, so its atoms have electrons in them for the first four energy levels. "
All but one of the elements on the left side of the periodic table are,(A) metalloids (B) liquids (C) metals (D) gases,C,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
Which statement is true about any group in the periodic table?,(A) It includes metals (B) metalloids (C) and nonmetals (D) b It includes elements with similar properties (E) c It includes gases (F) liquids (G) and solids (H) d It contains 18 different elements,B,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
number of protons in an atom,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,C,"The number of protons in an atom is called its atomic number. This number is very important because it is unique for atoms of a given element. All atoms of an element have the same number of protons, and every element has a different number of protons in its atoms. For example, all helium atoms have two protons, and no other elements have atoms with two protons. In the case of helium, the atomic number is 2. The atomic number of an element is usually written in front of and slightly below the elements symbol, like in the Figure 1.2 for helium. Atoms are neutral in electrical charge because they have the same number of negative electrons as positive protons. Therefore, the atomic number of an atom also tells you how many electrons the atom has. This, in turn, determines many of the atoms properties. "
row of the periodic table,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,B,"You can see how Mendeleev organized the elements in Figure 6.2. From left to right across each row, elements are arranged by increasing atomic mass. Mendeleev discovered that if he placed eight elements in each row and then continued on to the next row, the columns of the table would contain elements with similar properties. He called the columns groups. They are sometimes called families, because elements within a group are similar but not identical to one another, like people in a family. Mendeleevs table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleevs table, each period contains eight elements, and then the pattern repeats in the next row. "
table based on the atomic number of elements,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,G,"A periodic table is still used today to organize the elements. You can see a simple version of the modern periodic table in the Figure 1.1. The modern table is based on Mendeleevs table, except the modern table arranges the elements by increasing atomic number instead of atomic mass. Atomic number is the number of protons in an atom, and this number is unique for each element. The modern table has more elements than Mendeleevs table because many elements have been discovered since Mendeleevs time. "
Mendeleev left spaces in his periodic table for unknown elements.,(A) true (B) false,A,"Did you notice the blanks in Mendeleevs table? They are spaces that Mendeleev left blank for elements that had not yet been discovered when he created his table. He predicted that these missing elements would eventually be discovered. Based on their position in the table, he even predicted their properties. For example, he predicted a missing element in row 5 of group III. He also predicted that the missing element would have an atomic mass of 68 and be a relatively soft metal like other elements in this group. Scientists searched for the missing element, and they found it just a few years later. They named the new element gallium. Scientists searched for the other missing elements in Mendeleevs table and eventually found all of them. An important measure of a good model is its ability to make accurate predictions. This makes it a useful model. Clearly, Mendeleevs periodic table was a useful model. It helped scientists discover new elements and made sense of those that were already known. "
how an element is represented in the periodic table,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,E,"Rows of the modern periodic table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements: hydrogen (H) and helium (He). In contrast, periods 6 and 7 are so long that many of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary three-letter symbols, such as Uub. The number of each period represents the number of energy levels that have electrons in them for atoms of each element in that period. Q: Find calcium (Ca) in the Figure 1.1. How many energy levels have electrons in them for atoms of calcium? A: Calcium is in period 4, so its atoms have electrons in them for the first four energy levels. "
The modern periodic table is the same as Mendeleevs table but with more elements.,(A) true (B) false,B,"A periodic table is still used today to organize the elements. You can see a simple version of the modern periodic table in the Figure 1.1. The modern table is based on Mendeleevs table, except the modern table arranges the elements by increasing atomic number instead of atomic mass. Atomic number is the number of protons in an atom, and this number is unique for each element. The modern table has more elements than Mendeleevs table because many elements have been discovered since Mendeleevs time. "
table based on the atomic mass of elements,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,F,"A periodic table is still used today to organize the elements. You can see a simple version of the modern periodic table in the Figure 1.1. The modern table is based on Mendeleevs table, except the modern table arranges the elements by increasing atomic number instead of atomic mass. Atomic number is the number of protons in an atom, and this number is unique for each element. The modern table has more elements than Mendeleevs table because many elements have been discovered since Mendeleevs time. "
column of the periodic table,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,A,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
The modern periodic table has more than 100 elements.,(A) true (B) false,A,All known matter can be divided into a little more than 100 different substances called elements. 
amount of matter in an atom,(A) group (B) period (C) atomic number (D) atomic mass (E) chemical symbol (F) Mendeleevs periodic table (G) modern periodic table,D,"Here is a riddle for you to ponder: What do you and a tiny speck of dust in outer space have in common? Think you know the answer? Both you and the speck of dust consist of matter. So does the ground beneath your feet. In fact, everything you can see and touch is made of matter. The only things that are not matter are forms of energy. This would include things such as light and sound. Although forms of energy are not matter, the air and other substances they travel through are. So what is matter? Matter is defined as anything that has mass and volume. You may recall that atoms are the building blocks of matter. Even things as small as atoms have mass and volume. The more atoms, or matter, the more mass and volume are present. Different types of atoms have different amounts of mass and volume. So, its not enough to know the count of atoms to determine the mass. You must also know the type of atoms an item is made of. Mass and volume are just two ways to describe the physical property of a substance. Physical properties are all determined by the amounts and type of atoms that compose items. "
Elements called actinides are in period 7 of the periodic table.,(A) true (B) false,A,"Transition metals include the elements that are most often placed below the periodic table (the pink- and purple- shaded elements in the Figure 1.1). Those that follow lanthanum (La) are called lanthanides. They are all relatively reactive for transition metals. Those that follow actinium (Ac) are called actinides. They are all radioactive. This means that they are unstable, so they decay into different, more stable elements. Many of the actinides do not occur in nature but are made in laboratories. "
Elements in the same period of the periodic table have similar properties.,(A) true (B) false,B,"You can see how Mendeleev organized the elements in Figure 6.2. From left to right across each row, elements are arranged by increasing atomic mass. Mendeleev discovered that if he placed eight elements in each row and then continued on to the next row, the columns of the table would contain elements with similar properties. He called the columns groups. They are sometimes called families, because elements within a group are similar but not identical to one another, like people in a family. Mendeleevs table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleevs table, each period contains eight elements, and then the pattern repeats in the next row. "
Mendeleev developed his periodic table in the 1860s.,(A) true (B) false,A,"In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements. He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row. When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups. Mendeleevs table is called a periodic table and the rows are called periods. Thats because the table keeps repeating from row to row, and periodic means repeating. "
Mendeleev named the columns of his table periods.,(A) true (B) false,B,"In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements. He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row. When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups. Mendeleevs table is called a periodic table and the rows are called periods. Thats because the table keeps repeating from row to row, and periodic means repeating. "
Elements within a group of the periodic table are identical to each other.,(A) true (B) false,B,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
"In Mendeleevs table, each period contains 18 elements.",(A) true (B) false,B,"In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements. He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row. When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups. Mendeleevs table is called a periodic table and the rows are called periods. Thats because the table keeps repeating from row to row, and periodic means repeating. "
Mendeleevs used his table to predict unknown elements.,(A) true (B) false,A,"Did you notice the blanks in Mendeleevs table? They are spaces that Mendeleev left blank for elements that had not yet been discovered when he created his table. He predicted that these missing elements would eventually be discovered. Based on their position in the table, he even predicted their properties. For example, he predicted a missing element in row 5 of group III. He also predicted that the missing element would have an atomic mass of 68 and be a relatively soft metal like other elements in this group. Scientists searched for the missing element, and they found it just a few years later. They named the new element gallium. Scientists searched for the other missing elements in Mendeleevs table and eventually found all of them. An important measure of a good model is its ability to make accurate predictions. This makes it a useful model. Clearly, Mendeleevs periodic table was a useful model. It helped scientists discover new elements and made sense of those that were already known. "
The elements Mendeleev predicted were never discovered.,(A) true (B) false,B,"Did you notice the blanks in Mendeleevs table? They are spaces that Mendeleev left blank for elements that had not yet been discovered when he created his table. He predicted that these missing elements would eventually be discovered. Based on their position in the table, he even predicted their properties. For example, he predicted a missing element in row 5 of group III. He also predicted that the missing element would have an atomic mass of 68 and be a relatively soft metal like other elements in this group. Scientists searched for the missing element, and they found it just a few years later. They named the new element gallium. Scientists searched for the other missing elements in Mendeleevs table and eventually found all of them. An important measure of a good model is its ability to make accurate predictions. This makes it a useful model. Clearly, Mendeleevs periodic table was a useful model. It helped scientists discover new elements and made sense of those that were already known. "
Lanthanide elements are placed in period 2 of the modern periodic table.,(A) true (B) false,B,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
The chemical symbol for lead is Pb.,(A) true (B) false,A,"Besides atomic number, the periodic table includes each elements chemical symbol and class. Some tables include other information as well. The chemical symbol consists of one or two letters that come from the chemicals name in English or another language. The first letter is always written in upper case. The second letter, if there is one, is always written in lower case. For example, the symbol for lead is Pb. It comes from the Latin word plumbum, which means ""lead."" Find lead in Figure 6.3. What is its atomic number? You can access videos about lead and other elements in the modern periodic table at this URL:  . The classes of elements are metals, metalloids, and nonmetals. They are color-coded in the table. Blue stands for metals, orange for metalloids, and green for nonmetals. You can read about each of these three classes of elements later in the chapter, in the lesson ""Classes of Elements."" "
Most elements in the modern periodic table are metalloids.,(A) true (B) false,B,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
Krypton is a gaseous metal in group 18 of the periodic table.,(A) true (B) false,A,"Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why they are gases at room temperature. Radon, at the bottom of the group, is radioactive, so it constantly decays to other elements. Click image to the left or use the URL below. URL:  Q: Based on their position in the periodic table (Figure 1.1), how many valence electrons do you think noble gases have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the table above). Therefore, noble gases have eight valence electrons. "
Scientist first started looking for a way to organize the elements in the,(A) 1700s (B) late 1800s (C) early 1900s (D) 1980s,A,"In the 1860s, a scientist named Dmitri Mendeleev also saw the need to organize the elements. He created a table in which he arranged all of the elements by increasing atomic mass from left to right across each row. When he placed eight elements in each row and then started again in the next row, each column of the table contained elements with similar properties. He called the columns of elements groups. Mendeleevs table is called a periodic table and the rows are called periods. Thats because the table keeps repeating from row to row, and periodic means repeating. "
How many groups are there in Mendeleevs periodic table?,(A) 18 (B) 16 (C) 12 (D) 8,D,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
Examples that illustrate the meaning of periodic include,(A) phases of the moon (B) day and night (C) months of the year (D) all of the above,D,"You can see how Mendeleev organized the elements in Figure 6.2. From left to right across each row, elements are arranged by increasing atomic mass. Mendeleev discovered that if he placed eight elements in each row and then continued on to the next row, the columns of the table would contain elements with similar properties. He called the columns groups. They are sometimes called families, because elements within a group are similar but not identical to one another, like people in a family. Mendeleevs table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleevs table, each period contains eight elements, and then the pattern repeats in the next row. "
How many elements are represented in the modern periodic table?,(A) fewer than 50 (B) exactly 18 (C) about 65 (D) more than 100,D,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
Which of the following could be the chemical symbol of an element?,(A) SI (B) si (C) Si (D) iS,C,"In the Figure 1.1, each element is represented by its chemical symbol, which consists of one or two letters. The first letter of the symbol is always written in upper case, and the second letterif there is oneis always written in lower case. For example, the symbol for copper is Cu. It stands for cuprum, which is the Latin word for copper. The number above each symbol in the table is its unique atomic number. Notice how the atomic numbers increase from left to right and from top to bottom in the table. Q: Find the symbol for copper in the Figure 1.1. What is its atomic number? What does this number represent? A: The atomic number of copper is 29. This number represents the number of protons in each atom of copper. (Copper is the element that makes up the coil of wire in photo A of the opening sequence of photos.) "
Elements on the right side of the periodic table are,(A) metals (B) metalloids (C) nonmetals (D) actinides,C,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
Which sentence is true about periods of the periodic table?,(A) All the periods are the same length (B) There are a total of 18 periods (C) Some periods are longer than others (D) two of the above,C,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
Most metals are,(A) shiny (B) good conductors of heat (C) solids are room temperature (D) all of the above,D,"Metals are elements that are good conductors of electricity. They are the largest of the three classes of elements. In fact, most elements are metals. Look back at the modern periodic table (Figure 6.3) in this chapters lesson ""How Elements Are Organized."" Find the metals in the table. They are all the elements that are color-coded blue. Examples include sodium (Na), silver (Ag), and zinc (Zn). Metals have relatively high melting points, so almost all are solids at room temperature. The only exception is mercury (Hg), which is a liquid. Most metals are also good conductors of heat. Thats why they are used for cooking pots and stovetops. Metals have other characteristic properties as well. Most are shiny, ductile, and malleable. These properties are illustrated in Figure 6.5. You can dig deeper into the properties of metals at this URL: "
Most metals are,(A) dull (B) brittle (C) ductile (D) all of the above,C,"Metals are elements that are good conductors of electricity. They are the largest of the three classes of elements. In fact, most elements are metals. Look back at the modern periodic table (Figure 6.3) in this chapters lesson ""How Elements Are Organized."" Find the metals in the table. They are all the elements that are color-coded blue. Examples include sodium (Na), silver (Ag), and zinc (Zn). Metals have relatively high melting points, so almost all are solids at room temperature. The only exception is mercury (Hg), which is a liquid. Most metals are also good conductors of heat. Thats why they are used for cooking pots and stovetops. Metals have other characteristic properties as well. Most are shiny, ductile, and malleable. These properties are illustrated in Figure 6.5. You can dig deeper into the properties of metals at this URL: "
"If an element is ductile, this means that it can be",(A) used as an insulator (B) pulled into long thin shapes (C) used to conduct electricity (D) crushed into a powder,B,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
A nonmetal is an element that,(A) exists only as a gas or liquid (B) is completely unreactive (C) cannot conduct electricity (D) is shiny and malleable,C,"Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right across each period (row) of the periodic table, each element has atoms with one more proton and one more electron than the element before it. How might this be related to the properties of nonmetals? A: Because nonmetals are on the right side of the periodic table, they have more electrons in their outer energy level than elements on the left side or in the middle of the periodic table. The number of electrons in the outer energy level of an atom determines many of its properties. "
Nonmetals tend to have properties that are,(A) very similar to the properties of metals (B) in between those of metals and metalloids (C) more variable than the properties of metals (D) none of the above,C,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
Which of the following elements is a metal?,(A) phosphorus (B) selenium (C) lithium (D) boron,C,"Metals are elements that are good conductors of electricity. They are the largest of the three classes of elements. In fact, most elements are metals. Look back at the modern periodic table (Figure 6.3) in this chapters lesson ""How Elements Are Organized."" Find the metals in the table. They are all the elements that are color-coded blue. Examples include sodium (Na), silver (Ag), and zinc (Zn). Metals have relatively high melting points, so almost all are solids at room temperature. The only exception is mercury (Hg), which is a liquid. Most metals are also good conductors of heat. Thats why they are used for cooking pots and stovetops. Metals have other characteristic properties as well. Most are shiny, ductile, and malleable. These properties are illustrated in Figure 6.5. You can dig deeper into the properties of metals at this URL: "
Which statement about valence electrons is true?,(A) They are located in the outer energy level of an atom (B) They are potentially involved in chemical reactions (C) They determine whether an element can conduct electricity (D) all of the above,D,"Valence electrons are the electrons in the outer energy level of an atom that can participate in interactions with other atoms. Valence electrons are generally the electrons that are farthest from the nucleus. As a result, they may be attracted as much or more by the nucleus of another atom than they are by their own nucleus. "
Solid nonmetals are,(A) malleable (B) brittle (C) dull (D) two of the above,D,"Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have properties that are the opposite of those of metals. They also tend to vary more in their properties than metals do. For example, nonmetals have relatively low boiling points, so many of them are gases at room temperature. But several nonmetals are solids, including carbon and phosphorus (P). One nonmetal, bromine (Br), is a liquid at room temperature. Generally, nonmetals are also poor conductors of heat. In fact, they may be used for insulation. For example, the down filling in a down jacket is mostly air, which consists mainly of nitrogen (N) and oxygen (O). These nonmetal gases are poor conductors of heat, so they keep body heat in and cold air out. Solid nonmetals are dull rather than shiny. They are also brittle rather than ductile or malleable. You can see examples of solid nonmetals in Figure 6.6. You can learn more about specific nonmetals with the interactive table at this URL: http://library.thinkquest.org/36 "
Which of the following elements is a nonmetal?,(A) sulfur (B) aluminum (C) silver (D) zinc,A,"Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have properties that are the opposite of those of metals. They also tend to vary more in their properties than metals do. For example, nonmetals have relatively low boiling points, so many of them are gases at room temperature. But several nonmetals are solids, including carbon and phosphorus (P). One nonmetal, bromine (Br), is a liquid at room temperature. Generally, nonmetals are also poor conductors of heat. In fact, they may be used for insulation. For example, the down filling in a down jacket is mostly air, which consists mainly of nitrogen (N) and oxygen (O). These nonmetal gases are poor conductors of heat, so they keep body heat in and cold air out. Solid nonmetals are dull rather than shiny. They are also brittle rather than ductile or malleable. You can see examples of solid nonmetals in Figure 6.6. You can learn more about specific nonmetals with the interactive table at this URL: http://library.thinkquest.org/36 "
"If an element is malleable, this means that it can",(A) be formed into long thin shapes like wires (B) be formed into thin sheets without breaking (C) be used to conduct electric current (D) be used as an electric insulator,B,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
Which of the following elements is a metalloid?,(A) copper (B) helium (C) phosphorus (D) germanium,D,"Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between metals and nonmetals in terms of their properties. Q: How does the position of an element in the periodic table influence its properties? A: Elements are arranged in the periodic table by their atomic number, which is the number of protons in their atoms. Atoms are neutral in electric charge, so they always have the same number of electrons as protons. It is the number of electrons in the outer energy level of atoms that determines most of the properties of elements. "
Which element has a completely filled outer energy level?,(A) lithium (B) boron (C) fluorine (D) neon,D,"Electrons in the outermost energy level of an atom have a special significance. These electrons are called valence electrons, and they determine many of the properties of an atom. An atom is most stable if its outermost energy level contains as many electrons as it can hold. For example, helium has two electrons, both in the first energy level. This energy level can hold only two electrons, so heliums only energy level is full. This makes helium a very stable element. In other words, its atoms are unlikely to react with other atoms. Consider the elements fluorine and lithium, modeled in the Figure 1.3. Fluorine has seven of eight possible electrons in its outermost energy level, which is energy level II. It would be more stable if it had one more electron because this would fill its outermost energy level. Lithium, on the other hand, has just one of eight possible electrons in its outermost energy level (also energy level II). It would be more stable if it had one less electron because it would have a full outer energy level (now energy level I). Both fluorine and lithium are highly reactive elements because of their number of valence electrons. Fluorine will readily gain one electron and lithium will just as readily give up one electron to become more stable. In fact, lithium and fluorine will react together as shown in the Figure 1.4. When the two elements react, lithium transfers its one extra electron to fluorine. Q: A neon atom has ten electrons. How many electrons does it have in its outermost energy level? How stable do you think a neon atom is? A: A neon atom has two electrons in energy level I and its remaining eight electrons in energy level II, which can "
class of elements that do not conduct electricity,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,C,"Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have properties that are the opposite of those of metals. They also tend to vary more in their properties than metals do. For example, nonmetals have relatively low boiling points, so many of them are gases at room temperature. But several nonmetals are solids, including carbon and phosphorus (P). One nonmetal, bromine (Br), is a liquid at room temperature. Generally, nonmetals are also poor conductors of heat. In fact, they may be used for insulation. For example, the down filling in a down jacket is mostly air, which consists mainly of nitrogen (N) and oxygen (O). These nonmetal gases are poor conductors of heat, so they keep body heat in and cold air out. Solid nonmetals are dull rather than shiny. They are also brittle rather than ductile or malleable. You can see examples of solid nonmetals in Figure 6.6. You can learn more about specific nonmetals with the interactive table at this URL: http://library.thinkquest.org/36 "
word that describes most solid nonmetals,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,G,"Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have properties that are the opposite of those of metals. They also tend to vary more in their properties than metals do. For example, nonmetals have relatively low boiling points, so many of them are gases at room temperature. But several nonmetals are solids, including carbon and phosphorus (P). One nonmetal, bromine (Br), is a liquid at room temperature. Generally, nonmetals are also poor conductors of heat. In fact, they may be used for insulation. For example, the down filling in a down jacket is mostly air, which consists mainly of nitrogen (N) and oxygen (O). These nonmetal gases are poor conductors of heat, so they keep body heat in and cold air out. Solid nonmetals are dull rather than shiny. They are also brittle rather than ductile or malleable. You can see examples of solid nonmetals in Figure 6.6. You can learn more about specific nonmetals with the interactive table at this URL: http://library.thinkquest.org/36 "
smallest class of elements,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,B,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
All metalloids are solids are room temperature.,(A) true (B) false,A,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
only nonmetal that is a liquid at room temperature,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,F,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
Nonmetals are the second largest class of elements.,(A) true (B) false,A,"Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right across each period (row) of the periodic table, each element has atoms with one more proton and one more electron than the element before it. How might this be related to the properties of nonmetals? A: Because nonmetals are on the right side of the periodic table, they have more electrons in their outer energy level than elements on the left side or in the middle of the periodic table. The number of electrons in the outer energy level of an atom determines many of its properties. "
word that describes most metals,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,E,"Metals are elements that are good conductors of electricity. They are the largest of the three classes of elements. In fact, most elements are metals. Look back at the modern periodic table (Figure 6.3) in this chapters lesson ""How Elements Are Organized."" Find the metals in the table. They are all the elements that are color-coded blue. Examples include sodium (Na), silver (Ag), and zinc (Zn). Metals have relatively high melting points, so almost all are solids at room temperature. The only exception is mercury (Hg), which is a liquid. Most metals are also good conductors of heat. Thats why they are used for cooking pots and stovetops. Metals have other characteristic properties as well. Most are shiny, ductile, and malleable. These properties are illustrated in Figure 6.5. You can dig deeper into the properties of metals at this URL: "
only metal that is a liquid at room temperature,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,D,"Metals are elements that are good conductors of electricity. They are the largest of the three classes of elements. In fact, most elements are metals. Look back at the modern periodic table (Figure 6.3) in this chapters lesson ""How Elements Are Organized."" Find the metals in the table. They are all the elements that are color-coded blue. Examples include sodium (Na), silver (Ag), and zinc (Zn). Metals have relatively high melting points, so almost all are solids at room temperature. The only exception is mercury (Hg), which is a liquid. Most metals are also good conductors of heat. Thats why they are used for cooking pots and stovetops. Metals have other characteristic properties as well. Most are shiny, ductile, and malleable. These properties are illustrated in Figure 6.5. You can dig deeper into the properties of metals at this URL: "
Elements with eight valence electron are unreactive.,(A) true (B) false,A,"Because the noble gases are the least reactive of all elements, their eight valence electrons are used as the standard for nonreactivity and to explain how other elements interact. This is stated as the octet (group of eight) rule. According to this rule, atoms react to form compounds that allow them to have a group of eight valence electrons like the noble gases. For example, sodium (with one valence electron) reacts with chlorine (with seven valence electrons) to form the stable compound sodium chloride (table salt). In this reaction, sodium donates an electron and chlorine accepts it, giving each element an octet of valence electrons. "
class of elements that conduct electricity,(A) metals (B) metalloids (C) nonmetals (D) mercury (E) ductile (F) bromine (G) brittle,A,"Metals are elements that can conduct electricity. They are one of three classes of elements (the other two classes are nonmetals and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table, except for hydrogen, are metals. There are several different types of metals, including alkali metals in group 1 of the periodic table, alkaline Earth metals in group 2, and transition metals in groups 3-12. The majority of metals are transition metals. "
Fluorine is an example of a metalloid.,(A) true (B) false,B,"Metalloids are elements that fall between metals and nonmetals in the periodic table. Just seven elements are metalloids, so they are the smallest class of elements. In Figure 6.3, they are color-coded orange. Examples of metalloids include boron (B), silicon (Si), and germanium (Ge). Metalloids have some properties of metals and some properties of nonmetals. For example, many metalloids can conduct electricity but only at certain temperatures. These metalloids are called semiconductors. Silicon is an example. It is used in computer chips. It is also the most common metalloid on Earth. It is shiny like a metal but brittle like a nonmetal. You see a sample of silicon in Figure 6.7. The figure also shows other examples of metalloids. You can learn more about the properties of metalloids at this URL: http://library.thinkquest.org/3659/p "
Nonmetals tend to give up electrons.,(A) true (B) false,B,"Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right across each period (row) of the periodic table, each element has atoms with one more proton and one more electron than the element before it. How might this be related to the properties of nonmetals? A: Because nonmetals are on the right side of the periodic table, they have more electrons in their outer energy level than elements on the left side or in the middle of the periodic table. The number of electrons in the outer energy level of an atom determines many of its properties. "
Metals have relatively high melting points.,(A) true (B) false,A,"Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have several other shared properties, including those listed below. Metals have relatively high melting points. This explains why all metals except for mercury are solids at room temperature. Most metals are good conductors of heat. Thats why metals such as iron, copper, and aluminum are used for pots and pans. Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny. The majority of metals are ductile. This means that they can be pulled into long, thin shapes, like the aluminum electric wires pictured in the Figure 1.1. Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An example is aluminum foil, also pictured in the Figure 1.1. Q: The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this property? A: The properties of metalsas well as of elements in the other classesdepend mainly on the number and arrangement of their electrons. "
Carbon is an example of a metalloid.,(A) true (B) false,B,"Metalloids are elements that fall between metals and nonmetals in the periodic table. Just seven elements are metalloids, so they are the smallest class of elements. In Figure 6.3, they are color-coded orange. Examples of metalloids include boron (B), silicon (Si), and germanium (Ge). Metalloids have some properties of metals and some properties of nonmetals. For example, many metalloids can conduct electricity but only at certain temperatures. These metalloids are called semiconductors. Silicon is an example. It is used in computer chips. It is also the most common metalloid on Earth. It is shiny like a metal but brittle like a nonmetal. You see a sample of silicon in Figure 6.7. The figure also shows other examples of metalloids. You can learn more about the properties of metalloids at this URL: http://library.thinkquest.org/3659/p "
Almost all nonmetals are solids are room temperature.,(A) true (B) false,B,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
Some nonmetals are semiconductors.,(A) true (B) false,B,"Most metalloids have some physical properties of metals and some physical properties of nonmetals. For example, metals are good conductors of both heat and electricity, whereas nonmetals generally cannot conduct heat or electricity. And metalloids? They fall between metals and nonmetals in their ability to conduct heat, and if they can conduct electricity, they usually can do so only at higher temperatures. Metalloids that can conduct electricity at higher temperatures are called semiconductors. Silicon is an example of a semiconductor. It is used to make the tiny electric circuits in computer chips. You can see a sample of silicon and a silicon chip in the Figure 1.2. Metalloids tend to be shiny like metals but brittle like nonmetals. Because they are brittle, they may chip like glass or crumble to a powder if struck. Other physical properties of metalloids are more variable, including their boiling and melting points, although all metalloids exist as solids at room temperature. Click image to the left or use the URL below. URL: "
Silicon is the most common metalloid on Earth.,(A) true (B) false,A,"Metalloids are elements that fall between metals and nonmetals in the periodic table. Just seven elements are metalloids, so they are the smallest class of elements. In Figure 6.3, they are color-coded orange. Examples of metalloids include boron (B), silicon (Si), and germanium (Ge). Metalloids have some properties of metals and some properties of nonmetals. For example, many metalloids can conduct electricity but only at certain temperatures. These metalloids are called semiconductors. Silicon is an example. It is used in computer chips. It is also the most common metalloid on Earth. It is shiny like a metal but brittle like a nonmetal. You see a sample of silicon in Figure 6.7. The figure also shows other examples of metalloids. You can learn more about the properties of metalloids at this URL: http://library.thinkquest.org/3659/p "
Metals generally have fewer valence electrons than nonmetals.,(A) true (B) false,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
The number of valence electrons determines an elements reactivity.,(A) true (B) false,A,"The electrons in the outer energy level of an atom are called valence electrons. It is valence electrons that are potentially involved in chemical reactions. The number of valence electrons determines an elements reactivity, or how likely the element is to react with other elements. The number of valence electrons also determines whether the element can conduct electric current. Thats because electric current is the flow of electrons. Table 6.1 shows how these properties vary in elements from each class. Metals such as lithium have an outer energy level that is almost empty. They ""want"" to give up their few valence electrons so they will have a full outer energy level. As a result, metals are very reactive and good conductors of electricity. Metalloids such as boron have an outer energy level that is about half full. These elements need to gain or lose too many electrons for a full outer energy level to come about easily. As a result, these elements are not very reactive. They may be able to conduct electricity but not very well. Some nonmetals, such as bromine, have an outer energy level that is almost full. They ""want"" to gain electrons so they will have a full outer energy level. As a result, these nonmetals are very reactive. Because they only accept electrons and do not give them up, they do not conduct electricity. Other nonmetals, such as neon, have a completely full outer energy level. Their electrons are already in the most stable arrangement possible. They are unreactive and do not conduct electricity. Element Description Element Lithium Description Lithium (Li) is a highly reactive metal. It has just one electron in its outer energy level. Lithium reacts explosively with water (see picture). It can react with moisture on skin and cause serious burns. Boron Boron (B) is a metalloid. It has three valence electrons and is less reactive than lithium. Boron compounds dissolved in water form boric acid. Dilute boric acid is weak enough to use as eye wash. Bromine Bromine (Br) is an extremely reactive nonmetal. In fact, reactions with fluorine are often explosive, as you can see in the URL below. Neon (Ne) is a nonmetal gas with a completely filled outer energy level. This makes it unreactive, so it doesnt combine with other elements. Neon is used for lighted signs like this one. You can learn why neon gives off light at this link:  Neon "
Elements that want to gain electrons are usually metals.,(A) true (B) false,B,"Metals are elements that can conduct electricity. They are one of three classes of elements (the other two classes are nonmetals and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table, except for hydrogen, are metals. There are several different types of metals, including alkali metals in group 1 of the periodic table, alkaline Earth metals in group 2, and transition metals in groups 3-12. The majority of metals are transition metals. "
The ability of an element to conduct electricity depends on its number of neutrons.,(A) true (B) false,B,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
Neon is more reactive than fluorine.,(A) true (B) false,B,"Reactivity is how likely an element is to react chemically with other elements. Some nonmetals are extremely reactive, whereas others are completely nonreactive. What explains this variation in nonmetals? The answer is their number of valence electrons. These are the electrons in the outer energy level of an atom that are involved in interactions with other atoms. Lets look at two examples of nonmetals, fluorine and neon. Simple atomic models of these two elements are shown in the Figure 1.2. Q: Which element, fluorine or neon, do you predict is more reactive? A: Fluorine is more reactive than neon. Thats because it has seven of eight possible electrons in its outer energy level, whereas neon already has eight electrons in this energy level. Although neon has just one more electron than fluorine in its outer energy level, that one electron makes a huge difference. Fluorine needs one more electron to fill its outer energy level in order to have the most stable arrangement of electrons. Therefore, fluorine readily accepts an electron from any element that is equally eager to give one up, Click image to the left or use the URL below. URL: "
column of elements in the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,F,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
Hydrogen is in the same group as the alkali metals because,(A) it is a metal (B) it is unreactive (C) it has one valence electron (D) it is in period 1 of the periodic table,C,"Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very eager to gain an electron. Click image to the left or use the URL below. URL: "
element in group 18 of the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,D,"Group 13 of the periodic table is also called the boron group because boron (B) is the first element at the top of the group (see Figure 1.2). Boron is also the only metalloid in this group. The other four elements in the groupaluminum (Al), gallium (Ga), indium (In), and thallium (Tl)are all metals. Group 13 elements have three valence electrons and are fairly reactive. All of them are solids at room temperature. "
Alkaline Earth metals are less reactive than,(A) noble gases (B) transition metals (C) alkali metals (D) all of the above,C,"All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metals in group 1. For example, alkaline Earth metals will react with cold water, but not explosively as alkali metals do. Because of their reactivity, alkaline Earth metals never exist as pure substances in nature. Instead, they are always found combined with other elements. The reactivity of alkaline Earth metals increases from the top to the bottom of the group. Thats because the atoms get bigger from the top to the bottom, so the valence electrons are farther from the nucleus. When valence electrons are farther from the nucleus, they are attracted less strongly by the nucleus and more easily removed from the atom. This makes the atom more reactive. Q: Alkali metals have just one valence electron. Why are alkaline Earth metals less reactive than alkali metals? A: It takes more energy to remove two valence electrons from an atom than one valence electron. This makes alkaline Earth metals with their two valence electrons less reactive than alkali metals with their one valence electron. "
metal in group 1 of the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,A,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
Which groups of the periodic table contain one or more metalloids?,(A) groups 12 (B) groups 312 (C) groups 1316 (D) groups 1718,C,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
The most reactive nonmetals are elements in the,(A) boron group (B) nitrogen group (C) oxygen group (D) halogen group,D,"The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are eager to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table. Alkali metals have just one valence electron, which they are equally eager to donate. Reactions involving halogens, especially halogens near the top of the group, may be explosive. You can see some examples in the video below. (Warning: Dont try any of these reactions at home!) Click image to the left or use the URL below. URL: "
radioactive transition metal,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,G,"Transition metals include the elements that are most often placed below the periodic table (the pink- and purple- shaded elements in the Figure 1.1). Those that follow lanthanum (La) are called lanthanides. They are all relatively reactive for transition metals. Those that follow actinium (Ac) are called actinides. They are all radioactive. This means that they are unstable, so they decay into different, more stable elements. Many of the actinides do not occur in nature but are made in laboratories. "
metal in group 2 of the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,B,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
All elements in the carbon group,(A) are solids are room temperature (B) have four valence electrons (C) are not very reactive (D) all of the above,D,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
metal in group 3 of the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,E,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
nonmetal in group 17 of the periodic table,(A) alkali metal (B) alkaline Earth metal (C) halogen (D) noble gas (E) transition metal (F) group (G) actinide,C,"Group 15 of the periodic table is also called the nitrogen group. The first element in the group is the nonmetal nitrogen (N), followed by phosphorus (P), another nonmetal. Arsenic (As) (Figure 1.4) and antimony (Sb) are the metalloids in this group, and bismuth (Bi) is a metal. All group 15 elements have five valence electrons, but they Germanium is a brittle, shiny, silvery- white metalloid. Along with silicon, it is used to make the tiny electric cir- cuits on computer chips. It is also used to make fiber optic cableslike the one pictured herethat carry telephone and other communication signals. vary in their reactivity. Nitrogen, for example, is not very reactive at all, whereas phosphorus is very reactive and found naturally only in combination with other substances. All group 15 elements are solids, except for nitrogen, which is a gas. "
Elements in group 1 include,(A) hydrogen (B) alkali metals (C) alkaline Earth metals (D) two of the above,D,"Group 15 of the periodic table is also called the nitrogen group. The first element in the group is the nonmetal nitrogen (N), followed by phosphorus (P), another nonmetal. Arsenic (As) (Figure 1.4) and antimony (Sb) are the metalloids in this group, and bismuth (Bi) is a metal. All group 15 elements have five valence electrons, but they Germanium is a brittle, shiny, silvery- white metalloid. Along with silicon, it is used to make the tiny electric cir- cuits on computer chips. It is also used to make fiber optic cableslike the one pictured herethat carry telephone and other communication signals. vary in their reactivity. Nitrogen, for example, is not very reactive at all, whereas phosphorus is very reactive and found naturally only in combination with other substances. All group 15 elements are solids, except for nitrogen, which is a gas. "
Alkali metals are,(A) soft (B) high in density (C) not very reactive (D) all of the above,A,"Besides being very reactive, alkali metals share a number of other properties. Alkali metals are all solids at room temperature. Alkali metals are low in density, and some of them float on water. Alkali metals are relatively soft. Some are even soft enough to cut with a knife, like the sodium pictured in the Figure 1.1. "
Which statement about alkaline Earth metals is true?,(A) They are more reactive than alkali metals (B) They are always found combined with other elements (C) Some of them are liquids at room temperature (D) They are all gold in color,B,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
The most reactive metals are the transition metals.,(A) true (B) false,B,"Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All except mercury (Hg) are solids at room temperature. Transition metals include the elements that are placed below the periodic table. Those that follow lanthanum (La) are called lanthanides. They are all shiny, relatively reactive metals. Those that follow Actinium (Ac) are called actinides. They are all radioactive metals. This means they are unstable. They break down into different, more stable elements. You can read more about radioactive elements in the chapter Nuclear Chemistry. Many of the actinides do not occur in nature but are made in laboratories. "
Transition metals tend to,(A) be shiny (B) boil at low temperatures (C) be very soft (D) be extremely reactive,A,"Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All except mercury (Hg) are solids at room temperature. Transition metals include the elements that are placed below the periodic table. Those that follow lanthanum (La) are called lanthanides. They are all shiny, relatively reactive metals. Those that follow Actinium (Ac) are called actinides. They are all radioactive metals. This means they are unstable. They break down into different, more stable elements. You can read more about radioactive elements in the chapter Nuclear Chemistry. Many of the actinides do not occur in nature but are made in laboratories. "
Alkaline Earth metals have three valence electrons.,(A) true (B) false,B,"All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metals in group 1. For example, alkaline Earth metals will react with cold water, but not explosively as alkali metals do. Because of their reactivity, alkaline Earth metals never exist as pure substances in nature. Instead, they are always found combined with other elements. The reactivity of alkaline Earth metals increases from the top to the bottom of the group. Thats because the atoms get bigger from the top to the bottom, so the valence electrons are farther from the nucleus. When valence electrons are farther from the nucleus, they are attracted less strongly by the nucleus and more easily removed from the atom. This makes the atom more reactive. Q: Alkali metals have just one valence electron. Why are alkaline Earth metals less reactive than alkali metals? A: It takes more energy to remove two valence electrons from an atom than one valence electron. This makes alkaline Earth metals with their two valence electrons less reactive than alkali metals with their one valence electron. "
The only nonmetal in the carbon group is,(A) nitrogen (B) boron (C) carbon (D) oxygen,C,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
Halogens form salts when they combine with,(A) alkali metals (B) alkaline Earth metals (C) transition metals (D) all metals,A,"Halide minerals are salts that form when salt water evaporates. Halite is a halide mineral, but table salt (see Figure bond with various metallic atoms to make halide minerals. All halides are ionic minerals, which means that they are typically soluble in water. Two carbonate minerals: (a) deep blue azurite and (b) opaque green malachite. Azurite and malachite are carbonates that contain copper instead of calcium. Beautiful halite crystal. "
Mercury is the only metal that is a liquid at room temperature.,(A) true (B) false,A,"Figure 1.3 shows a diagram of Mercurys interior. Mercury is one of the densest planets. Its relatively large, liquid core, made mostly of melted iron, takes up about 42% of the planets volume. "
Nobles gases are,(A) colorless (B) odorless (C) reactive (D) two of the above,D,"Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL: "
Boron is an example of an element in the metalloids class.,(A) true (B) false,A,"Metalloids are elements that fall between metals and nonmetals in the periodic table. Just seven elements are metalloids, so they are the smallest class of elements. In Figure 6.3, they are color-coded orange. Examples of metalloids include boron (B), silicon (Si), and germanium (Ge). Metalloids have some properties of metals and some properties of nonmetals. For example, many metalloids can conduct electricity but only at certain temperatures. These metalloids are called semiconductors. Silicon is an example. It is used in computer chips. It is also the most common metalloid on Earth. It is shiny like a metal but brittle like a nonmetal. You see a sample of silicon in Figure 6.7. The figure also shows other examples of metalloids. You can learn more about the properties of metalloids at this URL: http://library.thinkquest.org/3659/p "
Helium is an element in the group called the halogens.,(A) true (B) false,B,"Elements in group 17 are called halogens (see Figure 6.13). They are highly reactive nonmetals with seven valence electrons. The halogens react violently with alkali metals, which have one valence electron. The two elements combine to form a salt. For example, the halogen chlorine (Cl) and the alkali metal sodium (Na) react to form table salt, or sodium chloride (NaCl). The halogen group includes gases, liquids, and solids. For example, chlorine is a gas at room temperature, bromine (Br) is a liquid, and iodine (I) is a solid. You can watch a video demonstrating the reactivity of halogens at this URL:  . "
Hydrogen is an alkali metal.,(A) true (B) false,B,"Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very eager to gain an electron. Click image to the left or use the URL below. URL: "
Alkali metals are found only in compounds.,(A) true (B) false,A,"All the elements in group 1 have just one valence electron, so they are highly reactive. Group 1 is shown in Figure element in the universe. All the other elements in group 1 are alkali metals. They are the most reactive of all metals, and along with the elements in group 17, the most reactive elements. Because alkali metals are so reactive, they are only found in nature combined with other elements. The alkali metals are soft. Most are soft enough to cut with a knife. They are also low in density. Some of them even float on water. All are solids at room temperature. You can see a video demonstrating the reactivity of alkali metals with water at this URL:  (2:22). MEDIA Click image to the left or use the URL below. URL: "
Some alkali metals can float on water.,(A) true (B) false,A,"Besides being very reactive, alkali metals share a number of other properties. Alkali metals are all solids at room temperature. Alkali metals are low in density, and some of them float on water. Alkali metals are relatively soft. Some are even soft enough to cut with a knife, like the sodium pictured in the Figure 1.1. "
Calcium is an alkali metal.,(A) true (B) false,B,"For a better understanding of alkaline Earth metals, lets take a closer look at two of them: calcium (Ca) and strontium (Sr). Calcium is a soft, gray, nontoxic alkaline Earth metal. Although pure calcium doesnt exist in nature, calcium compounds are very common in Earths crust and in sea water. Calcium is also the most abundant metal in the human body, occurring as calcium compounds such as calcium phosphate and calcium carbonate. These calcium compounds are found in bones and make them hard and strong. The skeleton of the average adult contains about a kilogram of calcium. Because calciumlike bariumabsorbs x-rays, bones show up white in x-ray images. Calcium is an important component of a healthy human diet. Good food sources of calcium are pictured in Figure Q: What health problems might result from a diet low in calcium? A: Children who dont get enough calcium while their bones are forming may develop a deficiency disease called rickets, in which their bones are softer than normal and become bent and stunted. Adults who dont get enough calcium may develop a condition called osteoporosis, in which the bones lose calcium and become weak and brittle. People with osteoporosis are at high risk of bone fractures. Strontium is a silver-colored alkaline Earth metal that is even softer than calcium. Strontium compounds are quite common and have a variety of usesfrom fireworks to cement to toothpaste. In fireworks, strontium compounds produce deep red explosions. In toothpaste, the compound strontium chloride reduces tooth sensitivity. "
There is just one group of transition metals.,(A) true (B) false,B,"Transition metals are all the elements in groups 3-12 of the periodic table. In the periodic table pictured in Figure known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the opening image). Q: Transition metals have been called the most typical of all metals. What do you think this means? A: Unlike some other metals, transition metals have the properties that define the metals class. They are excellent conductors of electricity, for example, and they also have luster, malleability, and ductility. You can read more about these properties of transition metals below. "
Many of the actinides do not occur in nature.,(A) true (B) false,A,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
Elements in the oxygen group have eight valence electrons.,(A) true (B) false,B,"The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure 1.1). Across each row, or period, of the periodic table, the number of valence electrons in groups 1-2 and 13-18 increases by one from one element to the next. Within each column, or group, of the table, all the elements have the same number of valence electrons. This explains why all the elements in the same group have very similar chemical properties. For elements in groups 1-2 and 13-18, the number of valence electrons is easy to tell directly from the periodic table. This is illustrated in the simplified periodic table in the Figure 1.2. It shows just the numbers of valence electrons in each of these groups. For elements in groups 3-12, determining the number of valence electrons is more complicated. Q: Based on both periodic tables above (Figures 1.1 and 1.2), what are examples of elements that have just one valence electron? What are examples of elements that have eight valence electrons? How many valence electrons does oxygen (O) have? A: Any element in group 1 has just one valence electron. Examples include hydrogen (H), lithium (Li), and sodium (Na). Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons). Examples include neon (Ne), argon (Ar), and krypton (Kr). Oxygen, like all the other elements in group 16, has six valence electrons. "
Selenium is an alkaline Earth metal.,(A) true (B) false,B,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
The halogen group includes only gases.,(A) true (B) false,B,"The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine is red, and iodine and astatine are nearly black. Like other nonmetals, halogens cannot conduct electricity or heat. Compared with most other elements, halogens have relatively low melting and boiling points. "
Noble gases are found only in combination with other elements.,(A) true (B) false,B,"Noble gases are the least reactive of all known elements. Thats because with eight valence electrons, their outer energy levels are full. The only exception is helium, which has just two electrons. But helium also has a full outer energy level, because its only energy level (energy level 1) can hold a maximum of two electrons. A full outer energy level is the most stable arrangement of electrons. As a result, noble gases cannot become more stable by reacting with other elements and gaining or losing valence electrons. Therefore, noble gases are rarely involved in chemical reactions and almost never form compounds with other elements. "
Subscripts in a chemical formula are used to show the number of,(A) molecules in a substance (B) atoms of each element in a compound (C) different elements in a compound (D) protons in an element,B,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
There are millions of unique substances in the universe because elements can combine in many different ways to form,(A) mixtures (B) solutions (C) compounds (D) ions,C,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
Which chemical formula represents the compound hydrogen peroxide?,(A) H2 O (B) HO2 (C) H2 O 2 (D) H2 O 3,C,"The same elements may combine in different ratios. If they do, they form different compounds. Figure 7.2 shows some examples. Both water (H2 O) and hydrogen peroxide (H2 O2 ) consist of hydrogen and oxygen. However, they have different ratios of the two elements. As a result, water and hydrogen peroxide are different compounds with different properties. If youve ever used hydrogen peroxide to disinfect a cut, then you know that it is very different from water! Both carbon dioxide (CO2 ) and carbon monoxide (CO) consist of carbon and oxygen, but in different ratios. How do their properties differ? "
Water is an example of a(n),(A) unique substance (B) chemical compound (C) covalent compound (D) all of the above,D,"Water vapor is an example of a gas. A gas is matter that has neither a fixed volume nor a fixed shape. Instead, a gas takes both the volume and the shape of its container. It spreads out to take up all available space. You can see an example in Figure 4.6. "
The chemical formula HCl represents the compound named,(A) hydrogen chloride (B) hydrogen carbide (C) methane (D) none of the above,A,"An acid is an ionic compound that produces positive hydrogen ions (H+ ) when dissolved in water. An example is hydrogen chloride (HCl). When it dissolves in water, its hydrogen ions and negative chloride ions (Cl ) separate, forming hydrochloric acid. This can be represented by the equation: HCl H2 O + ! H + Cl "
Which statement is true about water and hydrogen peroxide?,(A) Both substances have the same properties (B) Both substances have the same chemical formula (C) Both substances consist of hydrogen and oxygen (D) Both substances are mixtures of elements,C,"The same elements may combine in different ratios. If they do, they form different compounds. Figure 7.2 shows some examples. Both water (H2 O) and hydrogen peroxide (H2 O2 ) consist of hydrogen and oxygen. However, they have different ratios of the two elements. As a result, water and hydrogen peroxide are different compounds with different properties. If youve ever used hydrogen peroxide to disinfect a cut, then you know that it is very different from water! Both carbon dioxide (CO2 ) and carbon monoxide (CO) consist of carbon and oxygen, but in different ratios. How do their properties differ? "
Chemical bonds always involve,(A) ions (B) atoms (C) metals (D) electrons,D,A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds. Q: Why do you think that chemical bonds form? A: Chemical bonds form because they give atoms a more stable arrangement of electrons. 
Which statement is true about carbon dioxide and carbon monoxide?,(A) Both compounds consist of carbon and oxygen (B) Both compounds have all the same properties (C) Both compounds are harmless gases (D) all of the above,A,"Carbon monoxide (CO) is toxic to both plants and animals. CO is deadly to people in a confined space, such as a closed home. Carbon monoxide is odorless and colorless, so people cant tell when they are breathing it. Thats why homes should have carbon monoxide detectors. You can see one in Figure 22.7. "
How many valence electrons does an oxygen atom have?,(A) 2 (B) 4 (C) 6 (D) 8,C,"The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure 1.1). Across each row, or period, of the periodic table, the number of valence electrons in groups 1-2 and 13-18 increases by one from one element to the next. Within each column, or group, of the table, all the elements have the same number of valence electrons. This explains why all the elements in the same group have very similar chemical properties. For elements in groups 1-2 and 13-18, the number of valence electrons is easy to tell directly from the periodic table. This is illustrated in the simplified periodic table in the Figure 1.2. It shows just the numbers of valence electrons in each of these groups. For elements in groups 3-12, determining the number of valence electrons is more complicated. Q: Based on both periodic tables above (Figures 1.1 and 1.2), what are examples of elements that have just one valence electron? What are examples of elements that have eight valence electrons? How many valence electrons does oxygen (O) have? A: Any element in group 1 has just one valence electron. Examples include hydrogen (H), lithium (Li), and sodium (Na). Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons). Examples include neon (Ne), argon (Ar), and krypton (Kr). Oxygen, like all the other elements in group 16, has six valence electrons. "
The ratio of elements in a given compound,(A) is always 2 to 1 (B) is always the same (C) may vary (D) two of the above,B,"A compound is a unique substance that forms when two or more elements combine chemically. Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons. Click image to the left or use the URL below. URL:  Water is an example of a common chemical compound. As you can see in the Figure 1.1, each water molecule consists of two atoms of hydrogen and one atom of oxygen. Water always has this 2:1 ratio of hydrogen to oxygen. Like water, all compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. Q: Sometimes the same elements combine in different ratios. How can this happen if a compound always consists of the same elements in the same ratio? A: If the same elements combine in different ratios, they form different compounds. "
A given compound always has the same,(A) chemical formula (B) composition (C) volume (D) two of the above,D,"A compound is a unique substance that forms when two or more elements combine chemically. Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons. Click image to the left or use the URL below. URL:  Water is an example of a common chemical compound. As you can see in the Figure 1.1, each water molecule consists of two atoms of hydrogen and one atom of oxygen. Water always has this 2:1 ratio of hydrogen to oxygen. Like water, all compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. Q: Sometimes the same elements combine in different ratios. How can this happen if a compound always consists of the same elements in the same ratio? A: If the same elements combine in different ratios, they form different compounds. "
"When there is just one atom of an element in a molecule, what subscript is used for the element?",(A) 1 (B) 0 (C) 2 (D) No subscript is used,D,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
An oxygen atom has eight valence electrons.,(A) true (B) false,B,"Covalent bonds form because they give atoms a more stable arrangement of electrons. Look at the oxygen atoms in the Figure 1.2. Alone, each oxygen atom has six valence electrons. By sharing two pairs of valence electrons, each oxygen atom has a total of eight valence electrons. This fills its outer energy level, giving it the most stable arrangement of electrons. The shared electrons are attracted to both oxygen nuclei, and this force of attraction holds the two atoms together in the oxygen molecule. "
A molecule of carbon monoxide has two carbon atoms and one oxygen atom.,(A) true (B) false,B,"A molecule is any combination of two or more atoms. The oxygen in the air we breathe is two oxygen atoms connected by a chemical bond to form O2 , or molecular oxygen. A carbon dioxide molecule is a combination of one carbon atom and two oxygen atoms, CO2 . Because carbon dioxide includes two different elements, it is a compound as well as a molecule. A compound is any combination of two or more different elements. A compound has different properties from the elements that it contains. Elements and combinations of elements (compounds) make up all the many types of matter in the Universe. A chemical reaction is a process that breaks or forms the bonds between atoms of molecules and compounds. For example, two hydrogens and one oxygen bind together to form water, H2 O. The molecules that come together to start a chemical reaction are the reactants. So hydrogen and oxygen are the reactants. The product is the end result of a reaction. In this example, water is the product. Atoms also come together to form compounds much larger than water. It is some of these large compounds that come together to form the basis of the cell. So essentially, your cells are made out of compounds, which are made out of atoms. "
The types of bonds in chemical compounds determine many of their properties.,(A) true (B) false,A,"There are different types of compounds. They differ in the nature of the bonds that hold their atoms together. The type of bonds in a compound determines many of its properties. Three types of bonds are ionic, covalent, and metallic bonds. You will read about these three types in later lessons. You can also learn more about them by watching this video:  (7:18). MEDIA Click image to the left or use the URL below. URL: "
The same elements may form different compounds.,(A) true (B) false,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
The chemical formula for carbon dioxide is CO2 .,(A) true (B) false,A,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
A hydrogen atom has two electrons.,(A) true (B) false,B,"To understand why chemical bonds form, consider the common compound known as water, or H2 O. It consists of two hydrogen (H) atoms and one oxygen (O) atom. As you can see in the on the left side of the Figure 1.1, each hydrogen atom has just one electron, which is also its sole valence electron. The oxygen atom has six valence electrons. These are the electrons in the outer energy level of the oxygen atom. In the water molecule on the right in the Figure 1.1, each hydrogen atom shares a pair of electrons with the oxygen atom. By sharing electrons, each atom has electrons available to fill its sole or outer energy level. The hydrogen atoms each have a pair of shared electrons, so their first and only energy level is full. The oxygen atom has a total of eight valence electrons, so its outer energy level is full. A full outer energy level is the most stable possible arrangement of electrons. It explains why elements form chemical bonds with each other. "
Each element is represented by a unique chemical formula.,(A) true (B) false,B,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
The compound carbon dioxide has twice as many oxygen atoms as carbon atoms.,(A) true (B) false,A,"Look at the Figure 1.2 of water (H2 O) and hydrogen peroxide (H2 O2 ), and read about these two compounds. Both compounds consist of hydrogen and oxygen, but they have different ratios of the two elements. As a result, water and hydrogen peroxide are different compounds with different properties. If youve ever used hydrogen peroxide to disinfect a cut, then you know that it is very different from water! Q: Read the Figure 1.3 about carbon dioxide (CO2 ) and carbon monoxide (CO). Both compounds consist of carbon and oxygen, but in different ratios. How can you tell that carbon dioxide and carbon monoxide are different compounds? Carbon Dioxide: Every time you exhale, you release carbon dioxide into the air. Its an odorless, colorless gas. Car- bon dioxide contributes to global climate change, but it isnt directly harmful to hu- man health. Carbon Monoxide: Carbon monoxide is produced when matter burns. Its a colorless, odorless gas that is very harmful to human health. In fact, it can kill people in minutes. Because you cant see or smell carbon monoxide, it must be detected with an alarm. "
The same elements may combine in different ratios to form the same compound.,(A) true (B) false,B,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
Any molecule that contains only hydrogen and oxygen is water.,(A) true (B) false,B,"Water is a simple chemical compound. Each molecule of water contains two hydrogen atoms (H2 ) and one oxygen atom (O). Thats why the chemical formula for water is H2 O. If water is so simple, why is it special? Water is one of the few substances that exists on Earth in all three states of matter. Water occurs as a gas, a liquid and a solid. You drink liquid water and use it to shower. You breathe gaseous water vapor in the air. You may go ice skating on a pond covered with solid water ice in the winter. "
Different types of compounds differ in the types of bonds that hold their atoms together.,(A) true (B) false,A,"There are different types of compounds. They differ in the nature of the bonds that hold their atoms together. The type of bonds in a compound determines many of its properties. Three types of bonds are ionic, covalent, and metallic bonds. You will read about these three types in later lessons. You can also learn more about them by watching this video:  (7:18). MEDIA Click image to the left or use the URL below. URL: "
Both coal and diamond consist of atoms of carbon that are bonded together.,(A) true (B) false,A,"Diamond is a form of carbon in which each carbon atom is covalently bonded to four other carbon atoms. This forms a strong, rigid, three-dimensional structure (see Figure 1.1). Diamond is the hardest natural substance, and no other natural substance can scratch it. This property makes diamonds useful for cutting and grinding tools as well as for rings and other jewelry (see Figure 1.2). "
Most of the unique substances on Earth are compounds.,(A) true (B) false,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
When atoms combine chemically they form mixtures.,(A) true (B) false,B,"Not all combined substances are compounds. Some are mixtures. A mixture is a combination of two or more substances in any proportion. The substances in a mixture may be elements or compounds. The substances dont combine chemically to form a new substance, as they do in a compound. Instead, they keep their original properties and just intermix. Examples of mixtures include salt and water in the ocean and gases in the atmosphere. Other examples are pictured in Figure 3.12. "
A chemical bond consists of matter that connects two different atoms.,(A) true (B) false,B,A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds. Q: Why do you think that chemical bonds form? A: Chemical bonds form because they give atoms a more stable arrangement of electrons. 
pure substance that cannot be separated into any other substances,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,E,"A pure substance is called an element. An element is a pure substance because it cannot be separated into any other substances. Currently, 92 different elements are known to exist in nature, although additional elements have been formed in labs. All matter consists of one or more of these elements. Some elements are very common; others are relatively rare. The most common element in the universe is hydrogen, which is part of Earths atmosphere and a component of water. The most common element in Earths atmosphere is nitrogen, and the most common element in Earths crust is oxygen. Click image to the left or use the URL below. URL: "
unique substance that forms when elements combine chemically,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,C,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
particle of a compound that forms when atoms bond together,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,F,"The smallest particle of a compound that still has the compounds properties is a molecule. A molecule consists of two or more atoms that are joined together. For example, a molecule of water consists of two hydrogen atoms joined to one oxygen atom (see Figure 3.10). You can learn more about molecules at this link:  Some compounds form crystals instead of molecules. A crystal is a rigid, lattice-like framework of many atoms bonded together. Table salt is an example of a compound that forms crystals (see Figure 3.11). Its crystals are made up of many sodium and chloride ions. Ions are electrically charged forms of atoms. You can actually watch crystals forming in this video:  . "
one of three types of chemical compounds,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,G,"There are different types of compounds. They differ in the nature of the bonds that hold their atoms together. The type of bonds in a compound determines many of its properties. Three types of bonds are ionic, covalent, and metallic bonds. You will read about these three types in later lessons. You can also learn more about them by watching this video:  (7:18). MEDIA Click image to the left or use the URL below. URL: "
symbol representing a chemical compound,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,B,"Elements are represented by chemical symbols. Examples are H for hydrogen and O for oxygen. Compounds are represented by chemical formulas. Youve already seen the chemical formula for water. Its H2 O. The subscript 2 after the H shows that there are two atoms of hydrogen in a molecule of water. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used. Table 7.1 shows some other examples of compounds and their chemical formulas. Name of Compound Electron Dot Diagram Numbers of Atoms Chemical Formula Name of Compound Hydrogen chloride Electron Dot Diagram Numbers of Atoms H=1 Cl = 1 Chemical Formula HCl Methane C=1 H=4 CH4 Hydrogen peroxide H=2 O=2 H2 O2 Carbon dioxide C=1 O=2 CO2 Problem Solving Problem: A molecule of ammonia consists of one atom of nitrogen (N) and three atoms of hydrogen (H). What is its chemical formula? Solution: The chemical formula is NH3 . You Try It! Problem: A molecule of nitrogen dioxide consists of one atom of nitrogen (N) and two atoms of oxygen (O). What is its chemical formula? "
particle in the outer energy level of an atom,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,D,"An electron is a particle outside the nucleus of an atom that has a negative electric charge. The charge of an electron is opposite but equal to the charge of a proton. Atoms have the same number of electrons as protons. As a result, the negative and positive charges ""cancel out."" This makes atoms electrically neutral. For example, a carbon atom has six electrons that ""cancel out"" its six protons. "
force of attraction between atoms or ions that share or transfer electrons,(A) chemical bond (B) chemical formula (C) compound (D) valence electron (E) element (F) molecule (G) ionic,A,A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds. Q: Why do you think that chemical bonds form? A: Chemical bonds form because they give atoms a more stable arrangement of electrons. 
Ionic compounds form when ions share electrons.,(A) true (B) false,B,"Ionic compounds contain ions of metals and nonmetals held together by ionic bonds. Ionic compounds do not form molecules. Instead, many positive and negative ions bond together to form a structure called a crystal. You can see an example of a crystal in Figure 7.5. It shows the ionic compound sodium chloride. Positive sodium ions (Na+ ) alternate with negative chloride ions (Cl ). The oppositely charged ions are strongly attracted to each other. Helpful Hints Naming Ionic Compounds Ionic compounds are named for their positive and negative ions. The name of the positive "
When halogens form ions they,(A) become positive in charge (B) become negative in charge (C) gain two electrons (D) two of the above,B,"Ions are highly reactive, especially as gases. They usually react with ions of opposite charge to form neutral compounds. For example, positive sodium ions and negative chloride ions react to form the neutral compound sodium chloride, commonly known as table salt. This occurs because oppositely charged ions attract each other. Ions with the same charge, on the other hand, repel each other. Ions are also deflected by a magnetic field, as you saw in the opening image of the northern lights. "
"In sodium chloride, sodium loses an electron to chlorine.",(A) true (B) false,A,"An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. Figure 7.3 shows how this happens. In row 1 of Figure 7.3, an atom of sodium donates an electron to an atom of chlorine (Cl). By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na+ . By gaining an electron, the chlorine atom becomes a chloride ion. It now has one more electron than protons, giving it a charge of -1. Negative ions are named by adding the suffix ide to the first part of the element name. The symbol for chloride is Cl . Sodium and chloride ions have equal but opposite charges. Opposites attract, so sodium and chloride ions attract each other. They cling together in a strong ionic bond. You can see this in row 2 of Figure 7.3. Brackets separate the ions in the diagram to show that the ions in the compound do not share electrons. You can see animations of sodium chloride forming at these URLs: http://web.jjay.cuny.edu/~acarpi/NSC/salt.htm "
Which two elements would not form ionic bonds?,(A) calcium and lithium (B) calcium and oxygen (C) lithium and oxygen (D) calcium and carbon,A,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
Ionic bonds form only between atoms of nonmetals.,(A) true (B) false,B,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
Energy is released when,(A) valence electrons are removed from an atom (B) valence electrons are gained by an atom (C) a positive ion forms (D) two of the above,B,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
A sodium ion has a charge of,(A) -1 (B) -2 (C) +1 (D) +2,C,"An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. Figure 7.3 shows how this happens. In row 1 of Figure 7.3, an atom of sodium donates an electron to an atom of chlorine (Cl). By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na+ . By gaining an electron, the chlorine atom becomes a chloride ion. It now has one more electron than protons, giving it a charge of -1. Negative ions are named by adding the suffix ide to the first part of the element name. The symbol for chloride is Cl . Sodium and chloride ions have equal but opposite charges. Opposites attract, so sodium and chloride ions attract each other. They cling together in a strong ionic bond. You can see this in row 2 of Figure 7.3. Brackets separate the ions in the diagram to show that the ions in the compound do not share electrons. You can see animations of sodium chloride forming at these URLs: http://web.jjay.cuny.edu/~acarpi/NSC/salt.htm "
The amount of energy needed to form an ion depends only on the number of valence electrons.,(A) true (B) false,B,"It takes energy to remove valence electrons from an atom because the force of attraction between the negative electrons and the positive nucleus must be overcome. The amount of energy needed depends on the element. Less energy is needed to remove just one or a few valence electrons than many. This explains why sodium and other alkali metals form positive ions so easily. Less energy is also needed to remove electrons from larger atoms in the same group. For example, in group 1, it takes less energy to remove an electron from francium (Fr) at the bottom of the group than from lithium (Li) at the top of the group (see the Figure 1.2). In bigger atoms, valence electrons are farther from the nucleus. As a result, the force of attraction between the valence electrons and the nucleus is weaker. Q: What do you think happens when an atom gains an electron and becomes a negative ion? A: Energy is released when an atom gains an electron. Halogens release the most energy when they form ions. As a result, they are very reactive elements. "
Francium has the same number of valence electrons as lithium.,(A) true (B) false,A,"Although all group 1 elements share certain properties, such as being very reactive, they are not alike in every way. Three different group 1 elements are described in more detail below. Notice the ways in which they differ from one another. Q: Why do you think hydrogen gas usually exists as diatomic molecules? A: Each hydrogen atom has just one electron. When two hydrogen atoms bond together, they share a pair of electrons. The shared electrons fill their only energy level, giving them the most stable arrangement of electrons. Potassium is a soft, silvery metal that ignites explosively in water. It easily loses its one valence electron to form positive potassium ions (K+ ), which are needed by all living cells. Potassium is so impor- tant for plants that it is found in almost all fertilizers, like the one shown here. Potassium is abundant in Earths crust in minerals such as feldspar. Francium has one of the largest, heaviest atoms of all elements. Its one valence electron is far removed from the nucleus, as you can see in the atomic model on the right, so it is easily removed from the atom. Francium is radioactive and quickly decays to form other elements such as radium. This is why francium is extremely rare in nature. Less than an ounce of francium is present on Earth at any given time. Q: Francium decays too quickly to form compounds with other elements. Which elements to you think it would bond with if it could? A: With one valence electron, francium would bond with a halogen element in group 17, which has seven valence electrons and needs one more to fill its outer energy level. Elements in group 17 include fluorine and chlorine. "
"In a given metals group of the periodic table, compared with elements closer to the top of the table, elements closer to the bottom",(A) have valence electrons that are farther from the nucleus (B) have valence electrons that are harder to remove from the atom (C) need more energy to form positive ions (D) all of the above,A,"Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All except mercury (Hg) are solids at room temperature. Transition metals include the elements that are placed below the periodic table. Those that follow lanthanum (La) are called lanthanides. They are all shiny, relatively reactive metals. Those that follow Actinium (Ac) are called actinides. They are all radioactive metals. This means they are unstable. They break down into different, more stable elements. You can read more about radioactive elements in the chapter Nuclear Chemistry. Many of the actinides do not occur in nature but are made in laboratories. "
Alkali metals release the most energy when they become ions.,(A) true (B) false,B,"It takes energy to remove valence electrons from an atom. The force of attraction between the negative electrons and positive nucleus must be overcome. The amount of energy needed depends on the element. Less energy is needed to remove just one or a few electrons than many. This explains why sodium and other alkali metals form positive ions so easily. Less energy is also needed to remove electrons from larger atoms in the same group. For example, in group 1, it takes less energy to remove an electron from francium (Fr) at the bottom of the group than from lithium (Li) at the top of the group (see Figure 7.4). In bigger atoms, valence electrons are farther from the nucleus. As a result, the force of attraction between the electrons and nucleus is weaker. What happens when an atom gains an electron and becomes a negative ion? Energy is released. Halogens release the most energy when they form ions. As a result, they are very reactive. "
Salt consists of molecules of sodium and chloride ions.,(A) true (B) false,B,"Compounds like sodium chloride form structures called crystals. A crystal is a rigid framework of many ions locked together in a repeating pattern. Ions are electrically charged forms of atoms. You can see a crystal of sodium chloride in the Figure 1.3. It is made up of many sodium and chloride ions. Sodium and chlorine combine to form sodium chloride, or table salt. A sodium chloride crystal consists of many sodium ions (blue) and chloride ions (green) arranged in a rigid framework. Click image to the left or use the URL below. URL:  Compounds such as carbon dioxide and water form molecules instead of crystals. A molecule is the smallest particle of a compound that still has the compounds properties. It consists of two or more atoms bonded together. You saw models of carbon dioxide and water molecules above. "
"When an atom of iodine becomes an ion, it is named iodide.",(A) true (B) false,A,"Like fluoride, other negative ions usually have names ending in -ide. Positive ions, on the other hand, are just given the element name followed by the word ion. For example, when a sodium atom loses an electron, it becomes a positive sodium ion. The charge of an ion is indicated by a plus (+) or minus sign (-), which is written to the right of and just above the ions chemical symbol. For example, the fluoride ion is represented by the symbol F , and the sodium ion is represented by the symbol Na+ . If the charge is greater than one, a number is used to indicate it. For example, iron (Fe) may lose two electrons to form an ion with a charge of plus two. This ion would be represented by the symbol Fe2+ . This and some other common ions are listed with their symbols in the Table 1.1. Cations Name of Ion Calcium ion Hydrogen ion Iron(II) ion Iron(III) ion Chemical Symbol Ca2+ H+ Fe2+ Fe3+ Anions Name of Ion Chloride Fluoride Bromide Oxide Chemical Symbol Cl F Br O2 Q: How does the iron(III) ion differ from the iron(II) ion? A: The iron(III) ion has a charge of +3, so it has one less electron than the iron(II) ion, which has a charge of +2. Q: What is the charge of an oxide ion? How does its number of electrons compare to its number of protons? A: An oxide ion has a charge of -2. It has two more electrons than protons. "
Ionic compounds are usually liquids at room temperature.,(A) true (B) false,B,Ionic compounds have many uses. Some are shown in the Figure 1.2. Many ionic compounds are used in industry. The human body needs several ions for good health. Having low levels of the ions can endanger important functions such as heartbeat. Solutions of ionic compounds can be used to restore the ions. 
Water is an example of an ionic compound.,(A) true (B) false,B,"Water (H2 O) is an example of a chemical compound. Water molecules always consist of two atoms of hydrogen and one atom of oxygen. Like water, all other chemical compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. "
An ionic bond forms when atoms of a nonmetal give up electrons to atoms of a metal.,(A) true (B) false,B,"An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. The Figure 1.1 shows how this happens. In row 1 of the Figure 1.1, an atom of sodium (Na) donates an electron to an atom of chlorine (Cl). By losing an electron, the sodium atom becomes a sodium ion. It now has more protons than electrons and a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na+ . By gaining an electron, the chlorine atom becomes a chloride ion. It now has more electrons than protons and a charge of -1. Negative ions are named by adding the suffix -ide to the first part of the element name. The symbol for chloride is Cl . Sodium and chloride ions have equal but opposite charges. Opposite electric charges attract each other, so sodium and chloride ions cling together in a strong ionic bond. You can see this in row 2 of the Figure 1.1. (Brackets separate the ions in the diagram to show that the ions in the compound do not actually share electrons.) When ionic bonds hold ions together, they form an ionic compound. The compound formed from sodium and chloride ions is named sodium chloride. It is commonly called table salt. "
Sodium and chloride ions have equal but opposite charges.,(A) true (B) false,A,"An ionic bond is the force of attraction that holds together positive and negative ions. It forms when atoms of a metallic element give up electrons to atoms of a nonmetallic element. Figure 7.3 shows how this happens. In row 1 of Figure 7.3, an atom of sodium donates an electron to an atom of chlorine (Cl). By losing an electron, the sodium atom becomes a sodium ion. It now has one less electron than protons, giving it a charge of +1. Positive ions such as sodium are given the same name as the element. The chemical symbol has a plus sign to distinguish the ion from an atom of the element. The symbol for a sodium ion is Na+ . By gaining an electron, the chlorine atom becomes a chloride ion. It now has one more electron than protons, giving it a charge of -1. Negative ions are named by adding the suffix ide to the first part of the element name. The symbol for chloride is Cl . Sodium and chloride ions have equal but opposite charges. Opposites attract, so sodium and chloride ions attract each other. They cling together in a strong ionic bond. You can see this in row 2 of Figure 7.3. Brackets separate the ions in the diagram to show that the ions in the compound do not share electrons. You can see animations of sodium chloride forming at these URLs: http://web.jjay.cuny.edu/~acarpi/NSC/salt.htm "
Metals need energy in order to become ions.,(A) true (B) false,A,"It takes energy to remove valence electrons from an atom. The force of attraction between the negative electrons and positive nucleus must be overcome. The amount of energy needed depends on the element. Less energy is needed to remove just one or a few electrons than many. This explains why sodium and other alkali metals form positive ions so easily. Less energy is also needed to remove electrons from larger atoms in the same group. For example, in group 1, it takes less energy to remove an electron from francium (Fr) at the bottom of the group than from lithium (Li) at the top of the group (see Figure 7.4). In bigger atoms, valence electrons are farther from the nucleus. As a result, the force of attraction between the electrons and nucleus is weaker. What happens when an atom gains an electron and becomes a negative ion? Energy is released. Halogens release the most energy when they form ions. As a result, they are very reactive. "
The bonds of crystals are very weak.,(A) true (B) false,B,"Different types of minerals break apart in their own way. Remember that all minerals are crystals. This means that the atoms in a mineral are arranged in a repeating pattern. This pattern determines how a mineral will break. When you break a mineral, you break chemical bonds. Because of the way the atoms are arranged, some bonds are weaker than other bonds. A mineral is more likely to break where the bonds between the atoms are weaker. "
Solid ionic compounds are good conductors of electricity.,(A) true (B) false,B,"The crystal structure of ionic compounds is strong and rigid. It takes a lot of energy to break all those strong ionic bonds. As a result, ionic compounds are solids with high melting and boiling points (see Table 7.2). The rigid crystals are brittle and more likely to break than bend when struck. As a result, ionic crystals tend to shatter. You can learn more about the properties of ionic compounds by watching the video at this URL:  MEDIA Click image to the left or use the URL below. URL:  Compare the melting and boiling points of these ionic compounds with those of water (0C and 100C), which is not an ionic compound. Ionic Compound Sodium chloride (NaCl) Calcium chloride (CaCl2 ) Barium oxide (BaO) Iron bromide (FeBr3 ) Melting Point (C) 801 772 1923 684 Boiling Point (C) 1413 1935 2000 934 Solid ionic compounds are poor conductors of electricity. The strong bonds between ions lock them into place in the crystal. However, in the liquid state, ionic compounds are good conductors of electricity. Most ionic compounds dissolve easily in water. When they dissolve, they separate into individual ions. The ions can move freely, so they are good conductors of electricity. Dissolved ionic compounds are called electrolytes. "
dissolved ionic compound,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,E,"The crystal structure of ionic compounds is strong and rigid. It takes a lot of energy to break all those ionic bonds. As a result, ionic compounds are solids with high melting and boiling points. You can see the melting and boiling points of several different ionic compounds in the Table 1.1. To appreciate how high they are, consider that the melting and boiling points of water, which is not an ionic compound, are 0 C and 100 C, respectively. Ionic Compound Sodium chloride (NaCl) Calcium chloride (CaCl2 ) Barium oxide (BaO) Iron bromide (FeBr3 ) Melting Point ( C) 801 772 1923 684 Boiling Point ( C) 1413 1935 2000 934 Solid ionic compounds are poor conductors of electricity. The strong bonds between their oppositely charged ions lock them into place in the crystal. Therefore, the charged particles cannot move freely and carry electric current, which is a flow of charge. But all that changes when ionic compounds dissolve in water. When they dissolve, they separate into individual ions. The ions can move freely, so they can carry current. Dissolved ionic compounds are called electrolytes. The rigid crystals of ionic compounds are brittle. They are more likely to break than bend when struck. As a result, ionic crystals tend to shatter easily. Try striking salt crystals with a hammer and youll find that they readily break into smaller pieces. Click image to the left or use the URL below. URL: "
unique substance that forms when a metal and a nonmetal combine chemically,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,C,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
example of an alkali metal,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,F,"Besides being very reactive, alkali metals share a number of other properties. Alkali metals are all solids at room temperature. Alkali metals are low in density, and some of them float on water. Alkali metals are relatively soft. Some are even soft enough to cut with a knife, like the sodium pictured in the Figure 1.1. "
force of attraction that holds together positive and negative ions,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,B,"When it comes to electric charges, opposites attract, so positive and negative particles attract each other. You can see this in the Figure 1.2. This attraction explains why negative electrons keep moving around the positive nucleus of the atom. Like charges, on the other hand, repel each other, so two positive or two negative charges push apart. This is also shown in the diagram. The attraction or repulsion between charged particles is called electric force. The strength of electric force depends on the amount of electric charge on the particles and the distance between them. Larger charges or shorter distances result in greater force. Q: How do positive protons stay close together inside the nucleus of the atom if like charges repel each other? A: Other, stronger forces in the nucleus hold the protons together. "
example of a negative ion,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,G,"Sometimes atoms lose or gain electrons. Then they become ions. Ions have a positive or negative charge. Thats because they do not have the same number of electrons as protons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine in Figure 5.5. A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with a negative charge of minus one. "
charged particle that forms when an atom gains or loses electrons,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,A,"The girl pictured above became negatively charged because electrons flowed from the van de Graaff generator to her. Whenever electrons are transferred between objects, neutral matter becomes charged. This occurs even with individual atoms. Atoms are neutral in electric charge because they have the same number of negative electrons as positive protons. However, if atoms lose or gain electrons, they become charged particles called ions. You can see how this happens in the Figure 1.1. When an atom loses electrons, it becomes a positively charged ion, or cation. When an atom gains electrons, it becomes a negative charged ion, or anion. "
structure that forms when many positive and negative ions bond together,(A) ion (B) ionic bond (C) ionic compound (D) crystal (E) electrolyte (F) sodium (G) chloride,D,"Ions come together to create a molecule so that electrical charges are balanced; the positive charges balance the negative charges and the molecule has no electrical charge. To balance electrical charge, an atom may share its electron with another atom, give it away, or receive an electron from another atom. The joining of ions to make molecules is called chemical bonding. There are three main types of chemical bonds that are important in our discussion of minerals and rocks: Ionic bond: Electrons are transferred between atoms. An ion will give one or more electrons to another ion. Table salt, sodium chloride (NaCl), is a common example of an ionic compound. Note that sodium is on the left side of the periodic table and that chlorine is on the right side of the periodic table. In the Figure 1.2, an atom of lithium donates an electron to an atom of fluorine to form an ionic compound. The transfer of the electron gives the lithium ion a net charge of +1, and the fluorine ion a net charge of -1. These ions bond because they experience an attractive force due to the difference in sign of their charges. Covalent bond : In a covalent bond, an atom shares one or more electrons with another atom. Periodic Table of the Elements. Lithium (left) and fluorine (right) form an ionic compound called lithium fluoride. In the picture of methane (CH4 ) below (Figure 1.3), the carbon ion (with a net charge of +4) shares a single electron from each of the the four hydrogens. Covalent bonding is prevalent in organic compounds. In fact, your body is held together by electrons shared by carbons and hydrogens! Covalent bonds are also very strong, meaning it takes a lot of energy to break them apart. Hydrogen bond: These weak, intermolecular bonds are formed when the positive side of one polar molecule is attracted to the negative side of another polar molecule. Water is a classic example of a polar molecule because it has a slightly positive side, and a slightly negative side. In fact, this property is why water is so good at dissolving things. The positive side of the molecule is attracted to Methane is formed when four hydrogens and one carbon covalently bond. negative ions and the negative side is attracted to positive ions. "
When metallic elements become ions they,(A) gain electrons (B) become positively charged (C) become negatively charged (D) two of the above,B,"Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions. Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine (see Figure 1.1). A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1. "
Which two elements could form an ionic compound?,(A) carbon and oxygen (B) hydrogen and nitrogen (C) lithium and fluorine (D) boron and neon,C,"All compounds form when atoms of different elements share or transfer electrons. Compounds in which electrons are transferred from one atom to another are called ionic compounds. In this type of compound, electrons actually move between the atoms, rather than being shared between them. When atoms give up or accept electrons in this way, they become charged particles called ions. The ions are held together by ionic bonds, which form an ionic compound. Ionic compounds generally form between elements that are metals and elements that are nonmetals. For example, the metal calcium (Ca) and the nonmetal chlorine (Cl) form the ionic compound calcium chloride (CaCl2 ). In this compound, there are two negative chloride ions for each positive calcium ion. Because the positive and negative charges cancel out, an ionic compound is neutral in charge. Q: Now can you explain why calcium chloride prevents ice from forming on a snowy road? A: If calcium chloride dissolves in water, it breaks down into its ions (Ca2+ and Cl ). When water has ions dissolved in it, it has a lower freezing point. Pure water freezes at 0 C. With calcium and chloride ions dissolved in it, it wont freeze unless the temperature reaches -29 C or lower. "
Which statement about energy and ionic bonds is true?,(A) It takes energy to form a negative ion (B) Halogens need the most energy to become ions (C) It takes energy to remove valence electrons from an atom (D) It takes more energy to gain two electrons than one electron,C,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
Which of the following compounds is not an ionic compound?,(A) barium oxide (B) lithium oxide (C) carbon dioxide (D) calcium chloride,C,"The Table 1.1 shows four examples of compounds and their chemical formulas. The first two compounds are ionic compounds, and the second two are covalent compounds. Each formula shows the ratio of ions or atoms that make up the compound. Name of Compound Type of Compound Sodium chloride ionic Calcium iodide ionic Hydrogen peroxide covalent Carbon dioxide covalent Ratio of Ions or Atoms of Each Element 1 sodium ion (Na+ ) 1 chloride ion (Cl ) 1 calcium ion (Ca2+ ) 2 io- dide ions (I ) 2 hydrogen atoms (H) 2 oxygen atoms (O) 1 carbon atom (C) 2 oxy- gen atoms (O) Chemical Formulas NaCl CaI2 H2 O2 CO2 There is a different rule for writing the chemical formula for each type of compound. Ionic compounds are compounds in which positive metal ions and negative nonmetal ions are joined by ionic bonds. In these compounds, the chemical symbol for the positive metal ion is written first, followed by the symbol for the negative nonmetal ion. Click image to the left or use the URL below. URL:  Q: The ionic compound lithium fluoride consists of a ratio of one lithium ion (Li+ ) to one fluoride ion (F ). What is the chemical formula for this compound? A: The chemical formula is LiF. Covalent compounds are compounds in which nonmetals are joined by covalent bonds. In these compounds, the element that is farther to the left in the periodic table is written first, followed by the element that is farther to the right. If both elements are in the same group of the periodic table, the one with the higher period number is written first. Click image to the left or use the URL below. URL:  Q: A molecule of the covalent compound nitrogen dioxide consists of one nitrogen atom (N) and two oxygen atoms (O). What is the chemical formula for this compound? A: The chemical formula is NO2 . "
Properties of ionic compounds include,(A) high melting points (B) high boiling points (C) brittleness (D) all of the above,D,"The crystal structure of ionic compounds is strong and rigid. It takes a lot of energy to break all those strong ionic bonds. As a result, ionic compounds are solids with high melting and boiling points (see Table 7.2). The rigid crystals are brittle and more likely to break than bend when struck. As a result, ionic crystals tend to shatter. You can learn more about the properties of ionic compounds by watching the video at this URL:  MEDIA Click image to the left or use the URL below. URL:  Compare the melting and boiling points of these ionic compounds with those of water (0C and 100C), which is not an ionic compound. Ionic Compound Sodium chloride (NaCl) Calcium chloride (CaCl2 ) Barium oxide (BaO) Iron bromide (FeBr3 ) Melting Point (C) 801 772 1923 684 Boiling Point (C) 1413 1935 2000 934 Solid ionic compounds are poor conductors of electricity. The strong bonds between ions lock them into place in the crystal. However, in the liquid state, ionic compounds are good conductors of electricity. Most ionic compounds dissolve easily in water. When they dissolve, they separate into individual ions. The ions can move freely, so they are good conductors of electricity. Dissolved ionic compounds are called electrolytes. "
Ionic compounds are good conductors of electricity when they are,(A) shaped into wires (B) dissolved in water (C) formed into crystals (D) made of two metals,B,"Ionic compounds contain ions of metals and nonmetals held together by ionic bonds. Ionic compounds do not form molecules. Instead, many positive and negative ions bond together to form a structure called a crystal. You can see an example of a crystal in Figure 7.5. It shows the ionic compound sodium chloride. Positive sodium ions (Na+ ) alternate with negative chloride ions (Cl ). The oppositely charged ions are strongly attracted to each other. Helpful Hints Naming Ionic Compounds Ionic compounds are named for their positive and negative ions. The name of the positive "
In which of the following elements is the valence electron farthest from the nucleus?,(A) lithium (Li) (B) sodium (Na) (C) potassium (K) (D) rubidium (Rb),D,"Valence electrons are the electrons in the outer energy level of an atom that can participate in interactions with other atoms. Valence electrons are generally the electrons that are farthest from the nucleus. As a result, they may be attracted as much or more by the nucleus of another atom than they are by their own nucleus. "
any compound consisting of two or more nonmetals,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,G,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
Two hydrogen atoms may bond together to form a hydrogen,(A) ion (B) molecule (C) compound (D) two of the above,B,"Covalent bonds form because they give atoms a more stable arrangement of electrons. Look at the hydrogen atoms in Figure 7.7. Alone, each hydrogen atom has just one electron. By sharing electrons with another hydrogen atom, it has two electrons: its own and the one in the other hydrogen atom. The shared electrons are attracted to both hydrogen nuclei. This force of attraction holds the two atoms together as a molecule of hydrogen. Some atoms need to share more than one pair of electrons to have a full outer energy level. For example, an oxygen atom has six valence electrons. It needs two more electrons to fill its outer energy level. Therefore, it must form two covalent bonds. This can happen in many different ways. One way is shown in Figure 7.8. The oxygen atom in the figure has covalent bonds with two hydrogen atoms. This forms the covalent compound water. "
covalent bond in which neither atom has an electric charge,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,D,"Covalent bonds are chemical bonds between atoms of nonmetals that share valence electrons. In some covalent bonds, electrons are not shared equally between the two atoms. These are called polar covalent bonds. The Figure than the hydrogen atoms do because the nucleus of the oxygen atom has more positively charged protons. As a result, the oxygen atom becomes slightly negative in charge, and the hydrogen atoms become slightly positive in charge. Click image to the left or use the URL below. URL:  In other covalent bonds, electrons are shared equally. These bonds are called nonpolar covalent bonds. Neither atom attracts the shared electrons more strongly. As a result, the atoms remain neutral in charge. The oxygen (O2 ) molecule in the Figure 1.2 has two nonpolar bonds. The two oxygen nuclei have an equal force of attraction for their four shared electrons. "
An example of a covalent compound is,(A) sodium fluoride (B) calcium chloride (C) carbon dioxide (D) all of the above,C,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
covalent bond between two atoms of the same element,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,E,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
"In all covalent bonds, valence electrons are",(A) lost (B) gained (C) shared equally (D) shared,D,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
The compound that contains two oxygen atoms and one nitrogen atom is named,(A) oxygen nitride (B) dioxygen nitride (C) nitrogen dioxide (D) nitrogen monoxide,C,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
force of attraction holding together two atoms that share a pair of electrons,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,A,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
weak bond that forms between oppositely charged ends of two molecules,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,B,"Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weak as chemical bonds go. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds. Click image to the left or use the URL below. URL: "
What is the chemical formula for the compound in question 4?,(A) O2 N (B) N2 O (C) NO (D) NO2,D,"Elements are represented by chemical symbols. Examples are H for hydrogen and O for oxygen. Compounds are represented by chemical formulas. Youve already seen the chemical formula for water. Its H2 O. The subscript 2 after the H shows that there are two atoms of hydrogen in a molecule of water. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used. Table 7.1 shows some other examples of compounds and their chemical formulas. Name of Compound Electron Dot Diagram Numbers of Atoms Chemical Formula Name of Compound Hydrogen chloride Electron Dot Diagram Numbers of Atoms H=1 Cl = 1 Chemical Formula HCl Methane C=1 H=4 CH4 Hydrogen peroxide H=2 O=2 H2 O2 Carbon dioxide C=1 O=2 CO2 Problem Solving Problem: A molecule of ammonia consists of one atom of nitrogen (N) and three atoms of hydrogen (H). What is its chemical formula? Solution: The chemical formula is NH3 . You Try It! Problem: A molecule of nitrogen dioxide consists of one atom of nitrogen (N) and two atoms of oxygen (O). What is its chemical formula? "
covalent bond in which the two atoms are oppositely charged,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,C,"Covalent bonds are chemical bonds between atoms of nonmetals that share valence electrons. In some covalent bonds, electrons are not shared equally between the two atoms. These are called polar covalent bonds. The Figure than the hydrogen atoms do because the nucleus of the oxygen atom has more positively charged protons. As a result, the oxygen atom becomes slightly negative in charge, and the hydrogen atoms become slightly positive in charge. Click image to the left or use the URL below. URL:  In other covalent bonds, electrons are shared equally. These bonds are called nonpolar covalent bonds. Neither atom attracts the shared electrons more strongly. As a result, the atoms remain neutral in charge. The oxygen (O2 ) molecule in the Figure 1.2 has two nonpolar bonds. The two oxygen nuclei have an equal force of attraction for their four shared electrons. "
compound in which molecules have oppositely charged ends,(A) covalent bond (B) hydrogen bond (C) polar bond (D) nonpolar bond (E) diatomic bond (F) polar compound (G) covalent compound,F,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
Covalent bonds form only between atoms of different elements.,(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
A single covalent bond involves just one valence electron.,(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
Sharing electrons allows atoms to have a full outer energy level.,(A) true (B) false,A,"To understand why chemical bonds form, consider the common compound known as water, or H2 O. It consists of two hydrogen (H) atoms and one oxygen (O) atom. As you can see in the on the left side of the Figure 1.1, each hydrogen atom has just one electron, which is also its sole valence electron. The oxygen atom has six valence electrons. These are the electrons in the outer energy level of the oxygen atom. In the water molecule on the right in the Figure 1.1, each hydrogen atom shares a pair of electrons with the oxygen atom. By sharing electrons, each atom has electrons available to fill its sole or outer energy level. The hydrogen atoms each have a pair of shared electrons, so their first and only energy level is full. The oxygen atom has a total of eight valence electrons, so its outer energy level is full. A full outer energy level is the most stable possible arrangement of electrons. It explains why elements form chemical bonds with each other. "
Each hydrogen atom can form two covalent bonds.,(A) true (B) false,B,"Covalent bonds form because they give atoms a more stable arrangement of electrons. Look at the hydrogen atoms in Figure 7.7. Alone, each hydrogen atom has just one electron. By sharing electrons with another hydrogen atom, it has two electrons: its own and the one in the other hydrogen atom. The shared electrons are attracted to both hydrogen nuclei. This force of attraction holds the two atoms together as a molecule of hydrogen. Some atoms need to share more than one pair of electrons to have a full outer energy level. For example, an oxygen atom has six valence electrons. It needs two more electrons to fill its outer energy level. Therefore, it must form two covalent bonds. This can happen in many different ways. One way is shown in Figure 7.8. The oxygen atom in the figure has covalent bonds with two hydrogen atoms. This forms the covalent compound water. "
The hydrogen end of a water molecule is slightly negative in charge.,(A) true (B) false,B,"Water is simply two atoms of hydrogen and one atom of oxygen bonded together (Figure 1.1). The hydrogen ions are on one side of the oxygen ion, making water a polar molecule. This means that one side, the side with the hydrogen ions, has a slightly positive electrical charge. The other side, the side without the hydrogen ions, has a slightly negative charge. Despite its simplicity, water has remarkable properties. Water expands when it freezes, has high surface tension (because of the polar nature of the molecules, they tend to stick together), and others. Without water, life might not be able to exist on Earth and it certainly would not have the tremendous complexity and diversity that we see. "
Covalent bonds are found only in covalent compounds.,(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
Some covalent compounds contain atoms of just one element.,(A) true (B) false,B,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
Formaldehyde is an example of a covalent compound.,(A) true (B) false,A,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
Oxygen gas consists of individual oxygen atoms.,(A) true (B) false,B,Figure 15.3 shows the main gases in air. Nitrogen and oxygen make up 99 percent of air. Argon and carbon dioxide make up much of the rest. These percentages are the same just about everywhere in the atmosphere. Air also includes water vapor. The amount of water vapor varies from place to place. Thats why water vapor isnt included in Figure 15.3. It can make up as much as 4 percent of the air. Ozone is a molecule made of three oxygen atoms. Ozone collects in a layer in the stratosphere. 
An oxygen atom forms two covalent bonds.,(A) true (B) false,A,"Covalent bonds form because they give atoms a more stable arrangement of electrons. Look at the oxygen atoms in the Figure 1.2. Alone, each oxygen atom has six valence electrons. By sharing two pairs of valence electrons, each oxygen atom has a total of eight valence electrons. This fills its outer energy level, giving it the most stable arrangement of electrons. The shared electrons are attracted to both oxygen nuclei, and this force of attraction holds the two atoms together in the oxygen molecule. "
Oxygen always becomes negatively charged when it forms covalent bonds.,(A) true (B) false,B,"Covalent bonds form because they give atoms a more stable arrangement of electrons. Look at the oxygen atoms in the Figure 1.2. Alone, each oxygen atom has six valence electrons. By sharing two pairs of valence electrons, each oxygen atom has a total of eight valence electrons. This fills its outer energy level, giving it the most stable arrangement of electrons. The shared electrons are attracted to both oxygen nuclei, and this force of attraction holds the two atoms together in the oxygen molecule. "
"In naming a covalent compound, the element closest to the right of the periodic table is named first.",(A) true (B) false,B,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
The second element named in a covalent compound gets the suffix ide.,(A) true (B) false,A,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
Polar compounds tend to have higher boiling points than nonpolar compounds.,(A) true (B) false,A,"Changes of state from solid to liquid and from liquid to gas occur when matter gains energy. The energy allows individual molecules to separate and move apart from one another. It takes more energy to bring about these changes of state for polar molecules. Although hydrogen bonds are weak, they add to the energy needed for molecules to move apart from one another, so it takes higher temperatures for these changes of state to occur in polar compounds. This explains why polar compounds have relatively high melting and boiling points. The Table 1.1 compares melting and boiling points for some polar and nonpolar covalent compounds. Name of Compound (Chemical Formula) Methane (CH4 ) Ethylene (C2 H2 ) Ammonia (NH3 ) Water (H2 O) Polar or Nonpolar? Melting Point( C) Boiling Point ( C) nonpolar nonpolar polar polar -182 -169 -78 0 -162 -104 -33 100 Q: Which compound in the Table 1.1 do you think is more polar, ammonia or water? "
"If a bond forms between calcium and chlorine, the bond is covalent.",(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
Covalent bonds may form between,(A) atoms of different elements (B) atoms of the same element (C) ions of different elements (D) two of the above,D,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
Elements that normally occur as diatomic molecules include,(A) hydrogen (B) iodine (C) oxygen (D) all of the above,D,"The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine is red, and iodine and astatine are nearly black. Like other nonmetals, halogens cannot conduct electricity or heat. Compared with most other elements, halogens have relatively low melting and boiling points. "
Shared electrons in covalent bonds are always attracted to,(A) both nuclei (B) both nuclei equally (C) one nucleus more than the other (D) one nucleus only,A,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
How many covalent bonds must a hydrogen atom form to have a full outer energy level?,(A) 0 (B) 1 (C) 2 (D) 3,B,"To understand why chemical bonds form, consider the common compound known as water, or H2 O. It consists of two hydrogen (H) atoms and one oxygen (O) atom. As you can see in the on the left side of the Figure 1.1, each hydrogen atom has just one electron, which is also its sole valence electron. The oxygen atom has six valence electrons. These are the electrons in the outer energy level of the oxygen atom. In the water molecule on the right in the Figure 1.1, each hydrogen atom shares a pair of electrons with the oxygen atom. By sharing electrons, each atom has electrons available to fill its sole or outer energy level. The hydrogen atoms each have a pair of shared electrons, so their first and only energy level is full. The oxygen atom has a total of eight valence electrons, so its outer energy level is full. A full outer energy level is the most stable possible arrangement of electrons. It explains why elements form chemical bonds with each other. "
An example of a polar molecule is,(A) H2 O (B) CO2  (C) O2  (D) H2 ,A,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
Which statement about hydrogen bonds is true?,(A) They are very strong (B) They form between molecules (C) They form within molecules (D) two of the above,B,"Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weak as chemical bonds go. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds. Click image to the left or use the URL below. URL: "
"Compared with ionic compounds, covalent compounds",(A) have lower melting points (B) have higher boiling points (C) are better conductors of electricity (D) are more likely to dissolve in water,A,"Covalent compounds have different properties than ionic compounds because of their bonds. Covalent compounds exist as individual molecules rather than crystals. It takes less energy for individual molecules than ions in a crystal to pull apart. As a result, covalent compounds have lower melting and boiling points than ionic compounds. Many are gases or liquids at room temperature. Covalent compounds have shared electrons. These are not free to move like the transferred electrons of ionic compounds. This makes covalent compounds poor conductors of electricity. Many covalent compounds also do not dissolve in water as all ionic compounds do. "
Metallic bonds form because metals,(A) want to give up valence electrons (B) always share valence electrons (C) have many valence electrons (D) always gain valence electrons,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
Which statement about metallic bonds is true?,(A) They form between metals and nonmetals (B) They form between negative and positive ions (C) They form a lattice-like structure (D) two of the above,C,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
Which statement is true about all metals?,(A) They have one valence electron (B) They have freely moving electrons (C) They have more electrons than protons (D) They always gain electrons,B,"Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have several other shared properties, including those listed below. Metals have relatively high melting points. This explains why all metals except for mercury are solids at room temperature. Most metals are good conductors of heat. Thats why metals such as iron, copper, and aluminum are used for pots and pans. Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny. The majority of metals are ductile. This means that they can be pulled into long, thin shapes, like the aluminum electric wires pictured in the Figure 1.1. Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An example is aluminum foil, also pictured in the Figure 1.1. Q: The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this property? A: The properties of metalsas well as of elements in the other classesdepend mainly on the number and arrangement of their electrons. "
"In metallic bonds, the force of attraction is between",(A) positive and negative ions (B) ions and electrons (C) two different metals (D) neutrons and electrons,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
"Because of metallic bonds, metals",(A) are good conductors of electricity (B) can change shape without breaking (C) are ductile and malleable (D) all of the above,D,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
Metals are used to make electric wires because metals,(A) are ductile (B) are malleable (C) have freely moving electrons (D) two of the above,D,"Materials that have low resistance to electric current are called electric conductors. Many metalsincluding copper, aluminum, and steelare good conductors of electricity. The outer electrons of metal atoms are loosely bound and free to move, allowing electric current to flow. Water that has even a tiny amount of impurities is an electric conductor as well. Q: What do you think lightning rods are made of? A: Lightning rods are made of metal, usually copper or aluminum, both of which are excellent conductors of electricity. "
How does a metallic lattice differ from an ionic crystal?,(A) A metallic lattice is less flexible (B) A metallic lattice can change shape without breaking (C) A metallic lattice shatters when struck (D) all of the above,B,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
An alloy is a,(A) pure metal (B) compound of two or more metals (C) solid solution (D) mixture of nonmetals,C,"An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Several examples of alloys are described and pictured below. If you have braces on your teeth, you might even have this alloy in your mouth! Click image to the left or use the URL below. URL: "
Metal ions are surrounded by a sea of,(A) electrons (B) positive ions (C) negative ions (D) positive charges,A,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
An alloy of iron and carbon is,(A) more likely to rust than pure iron (B) weaker than pure iron (C) a mixture of two metals (D) known as steel,D,"Metals are useful for many purposes because of their unique properties. However, pure metals may be less useful than mixtures of metals. For example, iron is not as strong as steel, which is a mixture of iron and small amounts of carbon. Steel is so strong that it can hold up huge bridges, like the one Figure 7.15. Steel is also used to make skyscrapers, cargo ships, cars, and trains. Steel is an example of an alloy. An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is a solid solution. It is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Several other examples of alloys and their uses are shown in Figure 7.16. You can learn about an amazing alloy called memory wire at the URL below. If you have braces on your teeth, you may even have this alloy in your mouth! "
"The alloy that contains iron, carbon, nickel, and chromium is called",(A) stainless steel (B) bronze (C) brass (D) gold,A,"Metals are useful for many purposes because of their unique properties. However, pure metals may be less useful than mixtures of metals. For example, iron is not as strong as steel, which is a mixture of iron and small amounts of carbon. Steel is so strong that it can hold up huge bridges, like the one Figure 7.15. Steel is also used to make skyscrapers, cargo ships, cars, and trains. Steel is an example of an alloy. An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is a solid solution. It is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Several other examples of alloys and their uses are shown in Figure 7.16. You can learn about an amazing alloy called memory wire at the URL below. If you have braces on your teeth, you may even have this alloy in your mouth! "
type of ion a metal forms,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,D,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
structure formed by metallic bonding,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,G,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
example of an alloy,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,F,"An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Several examples of alloys are described and pictured below. If you have braces on your teeth, you might even have this alloy in your mouth! Click image to the left or use the URL below. URL: "
any element that is a good conductor of electricity,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,C,"Materials that have low resistance to electric current are called electric conductors. Many metalsincluding copper, aluminum, and steelare good conductors of electricity. The outer electrons of metal atoms are loosely bound and free to move, allowing electric current to flow. Water that has even a tiny amount of impurities is an electric conductor as well. Q: What do you think lightning rods are made of? A: Lightning rods are made of metal, usually copper or aluminum, both of which are excellent conductors of electricity. "
A metallic bond may form between a metal and any other element.,(A) true (B) false,B,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
example of a metal,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,E,"We rely on metals, such as aluminum, copper, iron, and gold. Look around the room. How many objects have metal parts? Metals are used in the tiny parts inside your computer, in the wires of anything that uses electricity, and to make the structure of a large building, such as the one shown in the Figure 3.23. "
Metals can be shaped into thin sheets.,(A) true (B) false,A,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
mixture of a metal with one or more other elements,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,A,"An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Several examples of alloys are described and pictured below. If you have braces on your teeth, you might even have this alloy in your mouth! Click image to the left or use the URL below. URL: "
Metal ions are surrounded by a sea of positive charge.,(A) true (B) false,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
force of attraction between a metal ion and valence electrons it shares with other ions of the metal,(A) alloy (B) metallic bond (C) metal (D) cation (E) iron (F) steel (G) metallic lattice,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
Special bonds form in metals that do not form in other classes of elements.,(A) true (B) false,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
Bronze has been used for thousands of years.,(A) true (B) false,A,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
Brass is an alloy of iron and copper.,(A) true (B) false,B,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
A metallic lattice is more rigid than an ionic crystal.,(A) true (B) false,B,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
Metallic bonds explain some of the unique properties of metals.,(A) true (B) false,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
Metal ions form bonds with the valence electrons around them.,(A) true (B) false,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
"Examples of metals include iron, zinc, and carbon.",(A) true (B) false,B,"We rely on metals, such as aluminum, copper, iron, and gold. Look around the room. How many objects have metal parts? Metals are used in the tiny parts inside your computer, in the wires of anything that uses electricity, and to make the structure of a large building, such as the one shown in the Figure 3.23. "
A metallic lattice is held together by ionic bonds.,(A) true (B) false,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
Iron is stronger than steel.,(A) true (B) false,B,"Metals are useful for many purposes because of their unique properties. However, pure metals may be less useful than mixtures of metals. For example, iron is not as strong as steel, which is a mixture of iron and small amounts of carbon. Steel is so strong that it can hold up huge bridges, like the one Figure 7.15. Steel is also used to make skyscrapers, cargo ships, cars, and trains. Steel is an example of an alloy. An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is a solid solution. It is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Several other examples of alloys and their uses are shown in Figure 7.16. You can learn about an amazing alloy called memory wire at the URL below. If you have braces on your teeth, you may even have this alloy in your mouth! "
Most metal objects are made of alloys.,(A) true (B) false,A,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
Bronze is a compound of copper and tin.,(A) true (B) false,B,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
Gold jewelry is usually made of pure gold.,(A) true (B) false,B,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
Which of the following changes is a chemical change?,(A) ice melting (B) wax melting (C) water boiling (D) wax burning,D,"Most chemical changes are not as dramatic as exploding fireworks, so how can you tell whether a chemical change has occurred? There are usually clues. You just need to know what to look for. A chemical change has probably occurred if bubbles are released, there is a change of color, or an odor is produced. Other clues include the release of heat, light, or loud sounds. Examples of chemical changes that produce these clues are shown in the Figure 1.1. Q: In addition to iron rusting, what is another example of matter changing color? Do you think this color change is a sign that a new chemical substance has been produced? A: Another example of matter changing color is a penny changing from reddish brown to greenish brown as it becomes tarnished. The color change indicates that a new chemical substance has been produced. Copper on the surface of the penny has combined with oxygen in the air to produce a different substance called copper oxide. Q: Besides food spoiling, what is another change that produces an odor? Is this a chemical change? A: When wood burns, it produces a smoky odor. Burning is a chemical change. Q: Which signs of chemical change do fireworks produce? A: Fireworks produce heat, light, and loud sounds. These are all signs of chemical change. "
Most chemical reactions take place in labs.,(A) true (B) false,B,"Chemistry can help you understand the world around you. Everything you touch, taste, or smell is made of chemicals, and chemical reactions underlie many common changes. For example, chemistry explains how food cooks, why laundry detergent cleans your clothes, and why antacid tablets relieve an upset stomach. Other examples are illustrated in the Figure 1.1. Chemistry even explains you! Your body is made of chemicals, and chemical changes constantly take place within it. Each of these pictures represents a way that chemicals and chemical reactions af- fect our lives. "
All changes in matter involve chemical reactions.,(A) true (B) false,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Which statement is true of all chemical reactions?,(A) They can go in just one direction (B) They occur only in science labs (C) They break and reform bonds (D) They create new elements,C,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
Evaporation is an example of a chemical change.,(A) true (B) false,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Reactants and products in chemical reactions may be,(A) elements (B) compounds (C) exactly the same compounds (D) two of the above,D,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
All chemical changes in matter involve,(A) changes of state (B) chemical reactions (C) changes in color (D) two of the above,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Reactants and products can be elements or compounds.,(A) true (B) false,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
Chemical reactions may occur quickly or slowly.,(A) true (B) false,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. Chemical reactions are represented by chemical equations, like the one below, in which reactants (on the left) are connected by an arrow to products (on the right). Reactants  Products Chemical reactions may occur quickly or slowly. Look at the two pictures in the Figure 1.1. Both represent chemical reactions. In the picture on the left, a reaction inside a fire extinguisher causes foam to shoot out of the extinguisher. This reaction occurs almost instantly. In the picture on the right, a reaction causes the iron tool to turn to rust. This reaction occurs very slowly. In fact, it might take many years for all of the iron in the tool to turn to rust. Q: What happens during a chemical reaction? Where do the reactants go, and where do the products come from? A: During a chemical reaction, chemical changes take place. Some chemical bonds break and new chemical bonds form. "
Which statement is true about a precipitate?,(A) It is a solid (B) It settles out of a liquid solution (C) It is evidence of a chemical reaction (D) all of the above,D,"When water evaporates, it leaves behind a solid precipitate of minerals, as shown in Figure 1.2. When the water in glass A evaporates, the dissolved mineral particles are left behind. Water can only hold a certain amount of dissolved minerals and salts. When the amount is too great to stay dissolved in the water, the particles come together to form mineral solids, which sink. Halite easily precipitates out of water, as does calcite. Some lakes, such as Mono Lake in California (Figure 1.3) or The Great Salt Lake in Utah, contain many mineral precipitates. Tufa towers form when calcium-rich spring water at the bottom of Mono Lake bubbles up into the alkaline lake. The tufa towers appear when lake level drops. "
Some chemical reactions can proceed in just one direction.,(A) true (B) false,A,"The arrow in Figure 8.2 shows that the reaction goes from left to right, from hydrogen and oxygen to water. The reaction can also go in the reverse direction. If an electric current passes through water, water molecules break down into molecules of hydrogen and oxygen. This reaction would be represented by a right-to-left arrow ( ) in Figure Many other reactions can also go in both forward and reverse directions. Often, a point is reached at which the forward and reverse reactions occur at the same rate. When this happens, there is no overall change in the amount of reactants and products. This point is called equilibrium, which refers to a balance between any opposing changes. You can see an animation of a chemical reaction reaching equilibrium at this URL: "
An example of a chemical change is water boiling.,(A) true (B) false,B,"A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. Click image to the left or use the URL below. URL: "
Freezing involves a chemical reaction.,(A) true (B) false,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
A banana turning brown is a chemical change.,(A) true (B) false,A,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
Wax melting is an example of a chemical reaction.,(A) true (B) false,B,"Look carefully at the Figures 1.1, 1.2, and 1.3. All of the photos demonstrate chemical reactions. For each photo, identify a sign that one or more chemical reactions have taken place. A burning campfire can warm you up on a cold day. Dissolving an antacid tablet in water produces a fizzy drink. Adding acid to milk produces solid curds of cottage cheese. Q: Did you ever make a volcano by pouring vinegar over a mountain of baking soda? If you did, you probably saw the mixture bubble up and foam over. Did a chemical reaction occur? How do you know? A: Yes, a chemical reaction occurred. You know because the bubbles are evidence that a gas has been produced and production of a gas is a sign of a chemical reaction. "
The products and reactants of a chemical reaction have different atoms.,(A) true (B) false,B,"The reactants and products in a chemical reaction contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. This happens because chemical bonds break in the reactants and new chemical bonds form in the products. Consider the chemical reaction in which water forms from oxygen and hydrogen gases. The Figure 1.2 represents this reaction. Bonds break in molecules of hydrogen and oxygen, and then new bonds form in molecules of water. In both reactants and products there are four hydrogen atoms and two oxygen atoms, but the atoms are combined differently in water. "
All chemical reactions are reversible.,(A) true (B) false,B,"Because chemical changes produce new substances, they often cannot be undone. For example, you cant change a fried egg back to a raw egg. Some chemical changes can be reversed, but only by other chemical changes. For example, to undo the tarnish on copper pennies, you can place them in vinegar. The acid in the vinegar reacts with the tarnish. This is a chemical change that makes the pennies bright and shiny again. You can try this yourself at home to see how well it works. "
Rusting is an example of a chemical change.,(A) true (B) false,A,"Most chemical changes are not as dramatic as exploding fireworks, so how can you tell whether a chemical change has occurred? There are usually clues. You just need to know what to look for. A chemical change has probably occurred if bubbles are released, there is a change of color, or an odor is produced. Other clues include the release of heat, light, or loud sounds. Examples of chemical changes that produce these clues are shown in the Figure 1.1. Q: In addition to iron rusting, what is another example of matter changing color? Do you think this color change is a sign that a new chemical substance has been produced? A: Another example of matter changing color is a penny changing from reddish brown to greenish brown as it becomes tarnished. The color change indicates that a new chemical substance has been produced. Copper on the surface of the penny has combined with oxygen in the air to produce a different substance called copper oxide. Q: Besides food spoiling, what is another change that produces an odor? Is this a chemical change? A: When wood burns, it produces a smoky odor. Burning is a chemical change. Q: Which signs of chemical change do fireworks produce? A: Fireworks produce heat, light, and loud sounds. These are all signs of chemical change. "
Condensation is a type of chemical reaction.,(A) true (B) false,B,"The chemical reaction in the Figure 1.2, in which water forms from hydrogen and oxygen, is an example of a synthesis reaction. In this type of reaction, two or more reactants combine to synthesize a single product. There are several other types of chemical reactions, including decomposition, replacement, and combustion reactions. The Table 1.1 compares these four types of chemical reactions. Type of Reaction Synthesis Decomposition General Equation A+B  C AB  A + B Example 2Na + Cl2  2NaCl 2H2 O 2H2 + O2 Type of Reaction Single Replacement Double Replacement Combustion General Equation A+BC  B+ AC AB+ CD  AD + CB fuel + oxygen  carbon dioxide + water Example 2K + 2H2 O  2KOH + H2 NaCl+ AgF  NaF + AgCl CH4 + 2O2  CO2 + 2H2 O Q: The burning of wood is a chemical reaction. Which type of reaction is it? A: The burning of woodor of anything elseis a combustion reaction. In the combustion example in the table, the fuel is methane gas (CH4 ). Click image to the left or use the URL below. URL: "
A change in temperature is a common sign of a chemical reaction.,(A) true (B) false,A,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
substance produced in a chemical reaction,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,E,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
force of attraction that breaks and reforms in a chemical reaction,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,D,"In chemical reactions, bonds break in the reactants and new bonds form in the products. The reactants and prod- ucts contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. Look at the example in Figure 8.2. It shows how water forms. Bonds break in molecules of hydrogen and oxygen. Then new bonds form in molecules of water. In both reactants and products, there are four hydrogen atoms and two oxygen atoms. But the atoms are combined differently in water. You can see another example at this URL: http://w "
substance that starts a chemical reaction,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,G,"Some reactions need extra help to occur quickly. They need another substance called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction. A catalyst isnt a reactant, so it isnt changed or used up in the reaction. Therefore, it can catalyze many other reactions. "
example of chemical change,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,F,"A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. Click image to the left or use the URL below. URL: "
balance between opposing changes,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,C,"When you walk outside on a cool day, does your body temperature drop? No, your body temperature stays stable at around 98.6 degrees Fahrenheit. Even when the temperature around you changes, your internal temperature stays the same. This ability of the body to maintain a stable internal environment despite a changing environment is called home- ostasis. Homeostasis doesnt just protect against temperature changes. Other aspects of your internal environment also stay stable. For example, your body closely regulates your fluid balance. You may have noticed that if you are slightly dehydrated, your urine is darker. Thats because the urine is more concentrated and less water is mixed in with it. "
process in which some substances become different substances,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
example of a physical change,(A) chemical reaction (B) melting (C) equilibrium (D) chemical bond (E) product (F) rusting (G) reactant,B,"A physical change is a change in one or more physical properties of matter without any change in chemical properties. In other words, matter doesnt change into a different substance in a physical change. Examples of physical change include changes in the size or shape of matter. Changes of statefor example, from solid to liquid or from liquid to gasare also physical changes. Some of the processes that cause physical changes include cutting, bending, dissolving, freezing, boiling, and melting. Four examples of physical change are pictured in the Figure Click image to the left or use the URL below. URL:  Q: In the Figure 1.1, what physical changes are occurring? A: The paper is being cut into smaller pieces, which is changing its size and shape. The ice cubes are turning into a puddle of liquid water because they are melting. This is a change of state. The tablet is disappearing in the glass of water because it is dissolving into particles that are too small to see. The lighthouse is becoming coated with ice as ocean spray freezes on its surface. This is another change of state. "
What do the formation of rust and the formation of cottage cheese have in common?,(A) Both occur very quickly (B) Both involve chemical reactions (C) Both are changes of state (D) Both are physical processes,B,"Lets return to the chemical reaction in which iron (Fe) combines with oxygen (O2 ) to form rust, or iron oxide (Fe2 O3 ). The equation for this reaction is: 4Fe+ 3O2  2Fe2 O3 This equation illustrates the use of coefficients to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula that shows how many atoms or molecules of the substance are involved in the reaction. From the equation for rusting, you can see that four atoms of iron combine with three molecules of oxygen to form two molecules of iron oxide. Q: Is the equation for the rusting reaction balanced? How can you tell? A: Yes, the equation is balanced. You can tell because there is the same number of each type of atom on both sides of the arrow. First count the iron atoms. There are four iron atoms in the reactants. There are also four iron atoms in the products (two in each of the two iron oxide molecules). Now count the oxygen atoms. There are six on each side of the arrow, confirming that the equation is balanced in terms of oxygen as well as iron. "
Which of the following changes does not involve chemical reactions?,(A) clouds forming (B) candles burning (C) leaves turning color (D) fire extinguishers foaming,A,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
"During chemical reactions, atoms are",(A) rearranged (B) created or destroyed (C) changed to new elements (D) two of the above,A,"The reactants and products in a chemical reaction contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. This happens because chemical bonds break in the reactants and new chemical bonds form in the products. Consider the chemical reaction in which water forms from oxygen and hydrogen gases. The Figure 1.2 represents this reaction. Bonds break in molecules of hydrogen and oxygen, and then new bonds form in molecules of water. In both reactants and products there are four hydrogen atoms and two oxygen atoms, but the atoms are combined differently in water. "
There is no overall change in reactants and products whenever a chemical reaction,(A) goes in just one direction (B) goes in two directions (C) reaches equilibrium (D) proceeds slowly,C,"The reactants and products in a chemical reaction contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. This happens because chemical bonds break in the reactants and new chemical bonds form in the products. Consider the chemical reaction in which water forms from oxygen and hydrogen gases. The Figure 1.2 represents this reaction. Bonds break in molecules of hydrogen and oxygen, and then new bonds form in molecules of water. In both reactants and products there are four hydrogen atoms and two oxygen atoms, but the atoms are combined differently in water. "
Evidence of chemical reactions include changes in,(A) state (B) color (C) temperature (D) two of the above,D,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
"In chemical equations, reactants and products are represented by",(A) plus signs and arrows (B) elements and compounds (C) coefficients and subscripts (D) chemical symbols and chemical formulas,D,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
A shorthand way of showing how atoms are rearranged in a chemical reaction is a chemical,(A) symbol (B) formula (C) equation (D) letter,C,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
"When there is more than one reactant in a chemical equation, they are separated by",(A) arrows (B) subscripts (C) plus signs (D) coefficients,C,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
Which chemical equation is not balanced?,(A) 2Na + Cl2  2NaCl (B) C + O2  CO2 (C) NO + O2  2NO2 (D) N2 + 3H2  2NH3,C,"Some chemical equations are more challenging to write. Consider the reaction in which hydrogen (H2 ) and oxygen (O2 ) combine to form water (H2 O). Hydrogen and oxygen are the reactants, and water is the product. To write a chemical equation for this reaction, you would start by writing symbols for the reactants and products: Equation 1: H2 + O2 ! H2 O Like equations in math, equations in chemistry must balance. There must be the same number of each type of atom in the products as there is in the reactants. In equation 1, count the number of hydrogen and oxygen atoms on each side of the arrow. There are two hydrogen atoms in both reactants and products. There are two oxygen atoms in the reactants but only one in the product. Therefore, equation 1 is not balanced. "
"In the reaction represented by the chemical equation 2Cu + O2  2CuO, new bonds are formed in",(A) 2Cu (B) O2  (C) CuO (D) none of the above,C,"In chemical reactions, bonds break in the reactants and new bonds form in the products. The reactants and prod- ucts contain the same atoms, but they are rearranged during the reaction. As a result, the atoms are in different combinations in the products than they were in the reactants. Look at the example in Figure 8.2. It shows how water forms. Bonds break in molecules of hydrogen and oxygen. Then new bonds form in molecules of water. In both reactants and products, there are four hydrogen atoms and two oxygen atoms. But the atoms are combined differently in water. You can see another example at this URL: http://w "
"If there is more than one product in a chemical equation, the products are separated by",(A) plus signs (B) minus signs (C) equals signs (D) two-way arrows,A,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
What is the missing coefficient in the following chemical equation? CH4 + ?O2  CO2 + 2H2 O,(A) 3 (B) 2 (C) 1 (D) 0,B,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
Chemical equations must be balanced because matter cannot be,(A) created (B) destroyed (C) changed (D) two of the above,D,"Why must chemical equations be balanced? Its the law! Matter cannot be created or destroyed in chemical reactions. This is the law of conservation of mass. In every chemical reaction, the same mass of matter must end up in the products as started in the reactants. Balanced chemical equations show that mass is conserved in chemical reactions. "
Which chemical equation is balanced?,(A) 2Na + Cl2  2NaCl (B) Na + 2Cl2  2NaCl (C) 2Na + 2Cl2  2NaCl (D) Na + Cl2  NaCl,A,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
Which chemical equation correctly represents the reaction in which carbon combines with oxygen?,(A) C2 + O2  2CO (B) C2 + 2O  C2 O2 (C) C + O2  CO2 (D) 2C + O  C2 O,C,"When scientists write chemical equations, they use chemical symbols and chemical formulas instead of names to represent reactants and products. Look at the chemical reaction illustrated in the Figure 1.1. In this reaction, carbon reacts with oxygen to produce carbon dioxide. Carbon is represented by the chemical symbol C. The chemical symbol for oxygen is O, but pure oxygen exists as diatomic (two-atom) molecules, represented by the chemical formula O2 . A molecule of the compound carbon dioxide consists of one atom of carbon and two atoms of oxygen, so carbon dioxide is represented by the chemical formula CO2 . Q: What is the chemical equation for this reaction? A: The chemical equation is: C + O2  CO2 Q: How have the atoms of the reactants been rearranged in the products of the reaction? What bonds have been broken, and what new bonds have formed? A: Bonds between the oxygen atoms in the oxygen molecule have been broken, and new bonds have formed between the carbon atom and the two oxygen atoms. "
What is the missing coefficient in the following chemical equation? ?NO + O2  2NO2 ?,(A) 0 (B) 1 (C) 2 (D) 4,C,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
The symbol 2O2 represents two molecules of oxygen.,(A) true (B) false,A,"When scientists write chemical equations, they use chemical symbols and chemical formulas instead of names to represent reactants and products. Look at the chemical reaction illustrated in the Figure 1.1. In this reaction, carbon reacts with oxygen to produce carbon dioxide. Carbon is represented by the chemical symbol C. The chemical symbol for oxygen is O, but pure oxygen exists as diatomic (two-atom) molecules, represented by the chemical formula O2 . A molecule of the compound carbon dioxide consists of one atom of carbon and two atoms of oxygen, so carbon dioxide is represented by the chemical formula CO2 . Q: What is the chemical equation for this reaction? A: The chemical equation is: C + O2  CO2 Q: How have the atoms of the reactants been rearranged in the products of the reaction? What bonds have been broken, and what new bonds have formed? A: Bonds between the oxygen atoms in the oxygen molecule have been broken, and new bonds have formed between the carbon atom and the two oxygen atoms. "
A coefficient of 1 usually is not written.,(A) true (B) false,A,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
Subscripts are used to balance chemical equations.,(A) true (B) false,B,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
The general form of a chemical equation is Reactants = Products.,(A) true (B) false,B,"A chemical equation is a shorthand way to sum up what occurs in a chemical reaction. The general form of a chemical equation is: Reactants  Products The reactants in a chemical equation are the substances that begin the reaction, and the products are the substances that are produced in the reaction. The reactants are always written on the left side of the equation and the products on the right. The arrow pointing from left to right shows that the reactants change into the products during the reaction. This happens when chemical bonds break in the reactants and new bonds form in the products. As a result, the products are different chemical substances than the reactants that started the reaction. Q: What is the general equation for the reaction in which iron rusts? A: Iron combines with oxygen to produce rust, which is the compound named iron oxide. This reaction could be represented by the general chemical equation below. Note that when there is more than one reactant, they are separated by plus signs (+). If more than one product were produced, plus signs would be used between them as well. Iron + Oxygen  Iron Oxide "
The first step in balancing a chemical equation is counting atoms.,(A) true (B) false,A,"Balancing a chemical equation involves a certain amount of trial and error. In general, however, you should follow these steps: 1. Count each type of atom in reactants and products. Does the same number of each atom appear on both sides of the arrow? If not, the equation is not balanced, and you need to go to step 2. 2. Place coefficients, as needed, in front of the symbols or formulas to increase the number of atoms or molecules of the substances. Use the smallest coefficients possible. Warning! Never change the subscripts in chemical formulas. Changing subscripts changes the substances involved in the reaction. Change only the coefficients. 3. Repeat steps 1 and 2 until the equation is balanced. Q: Balance this chemical equation for the reaction in which nitrogen (N2 ) and hydrogen (H2 ) combine to form ammonia (NH3 ): N2 + H2  NH3 A: First count the nitrogen atoms on both sides of the arrow. There are two nitrogen atoms in the reactants so there must be two in the products as well. Place the coefficient 2 in front of NH3 to balance nitrogen: N2 + H2  2 NH3 Now count the hydrogen atoms on both sides of the arrow. There are six hydrogen atoms in the products so there must also be six in the reactants. Place the coefficient 3 in front of H2 to balance hydrogen: N2 + 3 H2  2 NH3 "
A chemical equation must balance only when the reaction reversible.,(A) true (B) false,B,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
The symbol CO2 represents two molecules of carbon monoxide.,(A) true (B) false,B,"When scientists write chemical equations, they use chemical symbols and chemical formulas instead of names to represent reactants and products. Look at the chemical reaction illustrated in the Figure 1.1. In this reaction, carbon reacts with oxygen to produce carbon dioxide. Carbon is represented by the chemical symbol C. The chemical symbol for oxygen is O, but pure oxygen exists as diatomic (two-atom) molecules, represented by the chemical formula O2 . A molecule of the compound carbon dioxide consists of one atom of carbon and two atoms of oxygen, so carbon dioxide is represented by the chemical formula CO2 . Q: What is the chemical equation for this reaction? A: The chemical equation is: C + O2  CO2 Q: How have the atoms of the reactants been rearranged in the products of the reaction? What bonds have been broken, and what new bonds have formed? A: Bonds between the oxygen atoms in the oxygen molecule have been broken, and new bonds have formed between the carbon atom and the two oxygen atoms. "
The symbol 2H2 represents two atoms of hydrogen.,(A) true (B) false,B,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
Coefficients are used to balance chemical equations.,(A) true (B) false,A,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
"In balancing chemical equations, you should use the smallest subscripts possible.",(A) true (B) false,B,"Balancing a chemical equation involves a certain amount of trial and error. In general, however, you should follow these steps: 1. Count the number of each type of atom in reactants and products. Does the same number of each atom appear on both sides of the arrow? If not, the equation is not balanced, and you need to go to step 2. 2. Add coefficients to increase the number of atoms or molecules of reactants or products. Use the smallest coefficients possible. 3. Repeat steps 1 and 2 until the equation is balanced. Helpful Hint When you balance chemical equations, never change the subscripts in chemical formulas. Changing subscripts changes the substances involved in the reaction. Change only the coefficients. Work through the Problem Solving examples below. Then do the You Try It! problems to check your understand- ing. If you need more help, go to this URL:  (14:28). MEDIA Click image to the left or use the URL below. URL:  Problem Solving Problem: Balance this chemical equation: N2 + H2 ! NH3 Hints for balancing 1. Two N are needed in the products to match the two N (N2 ) in the reactants. Add the coefficient 2 in front of NH3 . Now N is balanced. 2. Six H are now needed in the reactants to match the six H in the products. Add the coefficient 3 in front of H2 . Now H is balanced. Solution: N2 + 3H2 ! 2NH3 Problem: Balance this chemical equation: CH4 + O2 ! CO2 + H2 O Solution: CH4 + 2O2 ! CO2 + 2H2 O You Try It! Problem: Balance these chemical equations: Zn + HCl ! ZnCl2 + H2 Cu + O2 ! CuO "
The number of each type of molecule must be the same on both sides of a chemical equation.,(A) true (B) false,B,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
Changing coefficients changes the substances involved in a chemical reaction.,(A) true (B) false,B,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
Chemists use a standard method to represent chemical reactions.,(A) true (B) false,A,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
The chemical equation H2 CO3  H2 O + CO2 is balanced.,(A) true (B) false,A,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
Water is the reactant in the chemical equation H2 O  H2 + O2 .,(A) true (B) false,A,"Some chemical equations are more challenging to write. Consider the reaction in which hydrogen (H2 ) and oxygen (O2 ) combine to form water (H2 O). Hydrogen and oxygen are the reactants, and water is the product. To write a chemical equation for this reaction, you would start by writing symbols for the reactants and products: Equation 1: H2 + O2 ! H2 O Like equations in math, equations in chemistry must balance. There must be the same number of each type of atom in the products as there is in the reactants. In equation 1, count the number of hydrogen and oxygen atoms on each side of the arrow. There are two hydrogen atoms in both reactants and products. There are two oxygen atoms in the reactants but only one in the product. Therefore, equation 1 is not balanced. "
symbolic representation of a chemical reaction,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,D,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
example of a coefficient,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,E,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
symbol of a chemical compound,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,G,"Elements are represented by chemical symbols. Examples are H for hydrogen and O for oxygen. Compounds are represented by chemical formulas. Youve already seen the chemical formula for water. Its H2 O. The subscript 2 after the H shows that there are two atoms of hydrogen in a molecule of water. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used. Table 7.1 shows some other examples of compounds and their chemical formulas. Name of Compound Electron Dot Diagram Numbers of Atoms Chemical Formula Name of Compound Hydrogen chloride Electron Dot Diagram Numbers of Atoms H=1 Cl = 1 Chemical Formula HCl Methane C=1 H=4 CH4 Hydrogen peroxide H=2 O=2 H2 O2 Carbon dioxide C=1 O=2 CO2 Problem Solving Problem: A molecule of ammonia consists of one atom of nitrogen (N) and three atoms of hydrogen (H). What is its chemical formula? Solution: The chemical formula is NH3 . You Try It! Problem: A molecule of nitrogen dioxide consists of one atom of nitrogen (N) and two atoms of oxygen (O). What is its chemical formula? "
example of a subscript,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,C,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
number showing how many atoms or molecules of a given element or compound are involved in a chemical,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,B,"In a chemical formula, the elements in a compound are represented by their chemical symbols, and the ratio of different elements is represented by subscripts. Consider the compound water as an example. Each water molecule contains two hydrogen atoms and one oxygen atom. Therefore, the chemical formula for water is: H2 O The subscript 2 after the H shows that there are two atoms of hydrogen in the molecule. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used in the chemical formula. "
symbol of an chemical element,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,A,"In the Figure 1.1, each element is represented by its chemical symbol, which consists of one or two letters. The first letter of the symbol is always written in upper case, and the second letterif there is oneis always written in lower case. For example, the symbol for copper is Cu. It stands for cuprum, which is the Latin word for copper. The number above each symbol in the table is its unique atomic number. Notice how the atomic numbers increase from left to right and from top to bottom in the table. Q: Find the symbol for copper in the Figure 1.1. What is its atomic number? What does this number represent? A: The atomic number of copper is 29. This number represents the number of protons in each atom of copper. (Copper is the element that makes up the coil of wire in photo A of the opening sequence of photos.) "
number showing how many atoms of a given element are in a molecule,(A) chemical symbol (B) coefficient (C) H2 (D) chemical equation (E) 2H (F) subscript (G) chemical formula,F,"Elements are represented by chemical symbols. Examples are H for hydrogen and O for oxygen. Compounds are represented by chemical formulas. Youve already seen the chemical formula for water. Its H2 O. The subscript 2 after the H shows that there are two atoms of hydrogen in a molecule of water. The O for oxygen has no subscript. When there is just one atom of an element in a molecule, no subscript is used. Table 7.1 shows some other examples of compounds and their chemical formulas. Name of Compound Electron Dot Diagram Numbers of Atoms Chemical Formula Name of Compound Hydrogen chloride Electron Dot Diagram Numbers of Atoms H=1 Cl = 1 Chemical Formula HCl Methane C=1 H=4 CH4 Hydrogen peroxide H=2 O=2 H2 O2 Carbon dioxide C=1 O=2 CO2 Problem Solving Problem: A molecule of ammonia consists of one atom of nitrogen (N) and three atoms of hydrogen (H). What is its chemical formula? Solution: The chemical formula is NH3 . You Try It! Problem: A molecule of nitrogen dioxide consists of one atom of nitrogen (N) and two atoms of oxygen (O). What is its chemical formula? "
one reactant breaking down into two or more products,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,C,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
The general equation for a synthesis reaction is,(A) AB  A + B (B) A + BC  B + AC (C) A+BC (D) AB + C  A + BC,C,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+BC In this equation, the letters A and B represent the reactants that begin the reaction, and the letter C represents the product that is synthesized in the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the synthesis of nitrogen dioxide (NO2 ) from nitric oxide (NO) and oxygen (O2 )? A: The equation for this synthesis reaction is: 2NO + O2  2NO2 "
ions changing places in two compounds,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,E,Replacement reactions involve ions. They occur when ions switch places in compounds. There are two types of replacement reactions: single and double. Both types are described below. 
Which of the following is a decomposition reaction?,(A) 2Na + Cl2  2NaCl (B) 2H2 O  2H2 + O2 (C) CH4 + O2  CO2 + H2 O (D) NaCl + AgF  NaF + AgCl,B,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
two reactants combining to form a single product,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,A,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
Which type of reaction is represented by the following chemical equation? 2K + 2H2 O  2KOH + H2,(A) double replacement (B) single replacement (C) decomposition (D) synthesis,B,"A single replacement reaction occurs when one ion takes the place of another in a single compound. This type of reaction has the general equation: A + BC ! B + AC Do you see how A has replaced B in the compound? The compound BC has become the compound AC. An example of a single replacement reaction occurs when potassium (K) reacts with water (H2 O). A colorless solid called potassium hydroxide (KOH) forms, and hydrogen gas (H2 ) is released. The equation for the reaction is: 2K + 2H2 O ! 2KOH + H2 Potassium is a highly reactive group 1 alkali metal, so its reaction with water is explosive. You can actually watch this reaction occurring at: http://commons.wikimedia.org/wiki/File:Potassium_water_20.theora.ogv . "
Which of the following is always a product of a combustion reaction?,(A) water (B) ashes (C) smoke (D) oxygen,A,"A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). For example, in the Figure usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO2 ) and water vapor (H2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is: Fuel + O2  CO2 + H2 O The burning of charcoal is a combustion reaction. "
substance reacting quickly with oxygen,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,B,A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). You can see an example of a combustion reaction in Figure 8.10. Combustion is commonly called burning. The substance that burns is usually referred to as fuel. The products of a combustion reaction include carbon dioxide (CO2 ) and water (H2 O). The reaction typically gives off heat and light as well. The general equation for a combustion reaction can be represented by: Fuel + O2 ! CO2 + H2 O 
one of the reactants in a combustion reaction,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,G,"A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). For example, in the Figure usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO2 ) and water vapor (H2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is: Fuel + O2  CO2 + H2 O The burning of charcoal is a combustion reaction. "
"In living cells, energy is produced by the process called",(A) photosynthesis (B) sugar synthesis (C) cellular respiration (D) glucose decomposition,C,"Cellular respiration is the process of extracting energy in the form of ATP from the glucose in the food you eat. How does cellular respiration happen inside of the cell? Cellular respiration is a three step process. Briefly: 1. In stage one, glucose is broken down in the cytoplasm of the cell in a process called glycolysis. 2. In stage two, the pyruvate molecules are transported into the mitochondria. The mitochondria are the organelles known as the energy ""powerhouses"" of the cells (Figure 1.1). In the mitochondria, the pyruvate, which have been converted into a 2-carbon molecule, enter the Krebs cycle. Notice that mitochondria have an inner membrane with many folds, called cristae. These cristae greatly increase the membrane surface area where many of the cellular respiration reactions take place. 3. In stage three, the energy in the energy carriers enters an electron transport chain. During this step, this energy is used to produce ATP. Oxygen is needed to help the process of turning glucose into ATP. The initial step releases just two molecules of ATP for each glucose. The later steps release much more ATP. Most of the reactions of cellular respira- tion are carried out in the mitochondria. "
one ion taking the place of another in a compound,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,D,Replacement reactions involve ions. They occur when ions switch places in compounds. There are two types of replacement reactions: single and double. Both types are described below. 
another term for a combustion reaction,(A) synthesis reaction (B) combustion reaction (C) decomposition reaction (D) single replacement reaction (E) double replacement reaction (F) burning (G) fuel,F,A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). You can see an example of a combustion reaction in Figure 8.10. Combustion is commonly called burning. The substance that burns is usually referred to as fuel. The products of a combustion reaction include carbon dioxide (CO2 ) and water (H2 O). The reaction typically gives off heat and light as well. The general equation for a combustion reaction can be represented by: Fuel + O2 ! CO2 + H2 O 
Which of the following is an example of a synthesis reaction?,(A) 2NO + O2  2NO2 (B) 2Na + Cl2  2NaCl2 (C) H2 O  H2 + O2 (D) two of the above,D,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
A decomposition reaction is represented by the general equation,(A) A + B + C  AB + C (B) A + BC  AB + C (C) AB  A + B (D) none of the above,C,"A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation: AB  A + B In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the decomposition of hydrogen peroxide (H2 O2 ) to water (H2 O) and oxygen (O2 )? A: The equation for this decomposition reaction is: 2 H2 O2  2 H2 O + O2 "
Which type of reaction is represented by the following chemical equation? NaCl + AgF  NaF + AgCl,(A) synthesis (B) decomposition (C) single replacement (D) double replacement,D,"An example of a synthesis reaction is the combination of sodium (Na) and chlorine (Cl) to produce sodium chloride (NaCl). This reaction is represented by the chemical equation: 2Na + Cl2 ! 2NaCl Sodium is a highly reactive metal, and chlorine is a poisonous gas (see Figure 8.6). The compound they synthesize has very different properties. It is table salt, which is neither reactive nor poisonous. In fact, salt is a necessary component of the human diet. "
A synthesis reaction occurs when two or more reactants combine to form a single product.,(A) true (B) false,A,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
Which of the following is always a reactant in a combustion reaction?,(A) water (B) oxygen (C) carbon dioxide (D) two of the above,B,"A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). For example, in the Figure usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO2 ) and water vapor (H2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is: Fuel + O2  CO2 + H2 O The burning of charcoal is a combustion reaction. "
Another term for a combustion reaction is decomposition.,(A) true (B) false,B,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
Methane is a,(A) hydrocarbon (B) component of natural gas (C) compound containing only carbon and hydrogen (D) all of the above,D,Natural gas is mostly methane. 
What do living cells use for fuel?,(A) oxygen (B) water (C) glucose (D) hydrocarbons,C,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
Fossil fuels such as oil and natural gas consist of hydrocarbons.,(A) true (B) false,A,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
The reaction in which carbon dioxide and water combine to form glucose,(A) is a combustion reaction (B) is called photosynthesis (C) takes place in all living cells (D) all of the above,B,"Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Together, these two processes provide energy to almost all of Earths organisms. The two processes are closely related, as you can see in the Figure 1.1. In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use. A: In photosynthesis, carbon dioxide (CO2 ) and water (H2 O) are the reactants. They combine using energy from light to produce oxygen (O2 ) and glucose (C6 H12 O6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy. "
The fuel that cells use for energy is oxygen.,(A) true (B) false,B,What goes into the cell? Oxygen and glucose are both reactants of cellular respiration. Oxygen enters the body when an organism breathes. Glucose enters the body when an organism eats. 
Plants combine carbon dioxide and water to form glucose.,(A) true (B) false,A,"What is the source of glucose for living things? It is made by plants and certain other organisms. The process in which glucose is made using energy in light is photosynthesis. This process requires carbon dioxide and water. It produces oxygen in addition to glucose. Photosynthesis consists of many chemical reactions. Overall, the reactions of photosynthesis can be summed up by this chemical equation: 6CO2 + 6H2 O + light energy ! C6 H12 O6 + 6O2 In words, this means that six molecules of carbon dioxide (CO2 ) combine with six molecules of water (H2 O) in the presence of light energy. This produces one molecule of glucose (C6 H12 O6 ) and six molecules of oxygen (O2 ). Use this interactive animation to learn more about photosynthesis: Click on this link for a song about photosynthesis to reinforce the basic ideas:  MEDIA Click image to the left or use the URL below. URL: "
Water decomposes when an electric current passes through it.,(A) true (B) false,A,"Another example of a decomposition reaction is illustrated in Figure 8.9. Water (H2 O) decomposes to hydrogen (H2 ) and oxygen (O2 ) when an electric current passes through it. This reaction is represented by the equation: 2H2 O ! 2H2 + O2 What is the reverse of this decomposition reaction? (Hint: How is water synthesized? You can look at this chapters ""Introduction to Chemical Reactions"" lesson to find out.) "
A combustion reaction usually gives off heat and light.,(A) true (B) false,A,"All combustion reactions are exothermic reactions. During a combustion reaction, a substance burns as it combines with oxygen. When substances burn, they usually give off energy as heat and light. Look at the big bonfire in the Figure 1.2. The combustion of wood is an exothermic reaction that releases a lot of energy as heat and light. You can see the light energy the fire is giving off. If you were standing near the fire, you would also feel its heat. "
The burning of glucose in cells is called cellular combustion.,(A) true (B) false,B,"Your own body cells burn fuel in combustion reactions. The fuel is glucose (C6 H12 O6 ), a simple sugar. The process in which combustion of glucose occurs in body cells is called cellular respiration. This combustion reaction provides energy for life processes. Cellular respiration can be summed up by the equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O Where does glucose come from? It is produced by plants during photosynthesis. In this process, carbon dioxide and water combine to form glucose. Which type of chemical reaction is photosynthesis? "
Sodium chloride forms in a decomposition reaction.,(A) true (B) false,B,"An example of a synthesis reaction is the combination of sodium (Na) and chlorine (Cl) to produce sodium chloride (NaCl). This reaction is represented by the chemical equation: 2Na + Cl2 ! 2NaCl Sodium is a highly reactive metal, and chlorine is a poisonous gas (see Figure 8.6). The compound they synthesize has very different properties. It is table salt, which is neither reactive nor poisonous. In fact, salt is a necessary component of the human diet. "
Methane and oxygen combine in a synthesis reaction.,(A) true (B) false,B,"A chemical reaction occurs when some substances change chemically to other substances. Chemical reactions are represented by chemical equations. Consider a simple chemical reaction, the burning of methane. In this reaction, methane (CH4 ) combines with oxygen (O2 ) in the air and produces carbon dioxide (CO2 ) and water vapor (H2 O). The reaction is represented by the following chemical equation: CH4 + 2O2  CO2 + 2H2 O This equation shows that one molecule of methane combines with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water vapor. All chemical equations must be balanced. This means that the same number of each type of atom must appear on both sides of the arrow. Q: Is the chemical equation for the burning of methane balanced? Count the atoms of each type on both sides of the arrow to find out. A: Yes, the equation is balanced. There is one carbon atom on both sides of the arrow. There are also four hydrogen atoms and four oxygen atoms on both sides of the arrow. "
One product of the reaction in question 5 is carbon dioxide.,(A) true (B) false,A,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
There are two types of decomposition reactions.,(A) true (B) false,B,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
Carbon dioxide forms only in combustion reactions.,(A) true (B) false,B,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
The general equation AB + CD  AD + CB represents a replacement reaction.,(A) true (B) false,A,A double replacement reaction occurs when two compounds exchange ions. This produces two new compounds. A double replacement reaction can be represented by the general equation: AB +CD ! AD +CB Do you see how B and D have changed places? Both reactant compounds have changed. An example of a double replacement reaction is sodium chloride (NaCl) reacting with silver fluoride (AgF). This reaction is represented by the equation: NaCl + AgF ! NaF + AgCl Cl and F have changed places. Can you name the products of this reaction? 
The chemical reaction 2K + 2H2 O  2KOH + H2 is a replacement reaction.,(A) true (B) false,A,"A single replacement reaction occurs when one ion takes the place of another in a single compound. This type of reaction has the general equation: A + BC ! B + AC Do you see how A has replaced B in the compound? The compound BC has become the compound AC. An example of a single replacement reaction occurs when potassium (K) reacts with water (H2 O). A colorless solid called potassium hydroxide (KOH) forms, and hydrogen gas (H2 ) is released. The equation for the reaction is: 2K + 2H2 O ! 2KOH + H2 Potassium is a highly reactive group 1 alkali metal, so its reaction with water is explosive. You can actually watch this reaction occurring at: http://commons.wikimedia.org/wiki/File:Potassium_water_20.theora.ogv . "
Which statement describes a role of energy in chemical reactions?,(A) Energy is created in exothermic reactions (B) Energy is always released in chemical reactions (C) Energy is needed for chemical reactions to start (D) Energy is destroyed in endothermic reactions,C,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
All chemical reactions need energy to,(A) form bonds in products (B) break bonds in reactants (C) get started (D) two of the above,D,"Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas wont occur without the spark of energy to begin the reaction. Q: Why is activation energy needed? Why wont a reaction occur without it? A: A reaction wont occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. "
The energy needed for photosynthesis is in the form of,(A) glucose (B) oxygen (C) light (D) heat,C,"Most of the energy used by living things comes either directly or indirectly from the sun. Thats because sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy  C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose, in turn, is used for energy by the cells of almost all living things. Photosynthetic organisms such as plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). Q: How do living things get energy from glucose? A: They break bonds in glucose and release the stored energy in the process of cellular respiration. "
Which statement about exothermic reactions is false?,(A) They need activation energy (B) They include combustion (C) They give off energy (D) They take in heat,D,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
"When products have less chemical energy than reactants, a chemical reaction",(A) is endothermic (B) is exothermic (C) absorbs energy (D) two of the above,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. Like the combustion reaction in a furnace, some chemical reactions require less energy to break bonds in reactants than is released when bonds form in products. These reactions, called exothermic reactions, release energy. In other chemical reactions, it takes more energy to break bonds in reactants than is released when bonds form in products. These reactions, called endothermic reactions, absorb energy. "
A constant input of energy is needed in,(A) exothermic reactions (B) endothermic reactions (C) all chemical reactions (D) none of the above,B,"Energy provides the ability to move or change matter from one state to another (for example, from solid to liquid). Every living thing needs energy to live and grow. Your body gets its energy from food, but that is only a small part of the energy you use every day. Cooking your food takes energy, and so does keeping it cold in the refrigerator or the freezer. The same is true for heating or cooling your home. Whether you are turning on a light in the kitchen or riding in a car to school, you are using energy. Billions of people all around the world use energy, so there is a huge demand for resources to provide all of this energy. Why do we need so much energy? The main reason is that almost everything that happens on Earth involves energy. "
You can increase the rate of a chemical reaction by,(A) increasing the temperature of reactants (B) decreasing the surface area of reactants (C) decreasing the concentration of reactants (D) all of the above,A,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. They are more likely to bump into one another and to collide with greater force. For example, when you fry an egg, turning up the heat causes the egg to cook faster. The same principle explains why storing food in a cold refrigerator reduces the rate at which food spoils (see Figure 8.16). Both food frying and food spoiling are chemical reactions that happen faster at higher temperatures. "
"According to the law of conservation of energy, energy",(A) cannot be created (B) cannot be destroyed (C) cannot change form (D) two of the above,D,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
Factors that affect reaction rates include,(A) temperature (B) concentration (C) surface area (D) all of the above,D,How fast a chemical reaction occurs is called the reaction rate. Several factors affect the rate of a given chemical reaction. They include the: temperature of reactants. concentration of reactants. surface area of reactants. presence of a catalyst. 
A catalyst,(A) can catalyze just one chemical reaction (B) is always changed in a chemical reaction (C) becomes a product in a chemical reaction (D) helps reactants come together in a chemical reaction,D,"Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions. Catalysts are not reactants, but they help reactants come together so they can react. You can see one way this happens in the animation at the URL below. By helping reactants come together, a catalyst decreases the activation energy needed to start a chemical reaction. This speeds up the reaction. Living things depend on catalysts to speed up many chemical reactions inside their cells. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take billions of years without it! "
Crushing a solid reactant into a powder will,(A) decrease the reactants surface area (B) increase the rate of the reaction (C) decrease the concentration of products (D) increase the temperature of reactants,B,"When a solid substance is involved in a chemical reaction, only the matter at the surface of the solid is exposed to other reactants. If a solid has more surface area, more of it is exposed and able to react. Therefore, increasing the surface area of solid reactants increases the reaction rate. For example, crushing a solid into a powder exposes more of the substance to other reactants. This may greatly speed up the reaction. You can see another example in Figure 8.18. Iron rusts when it combines with oxygen in the air. The iron hammer head and iron nails will both rust eventually. Which will rust faster? "
Which statement about catalysts is true?,(A) They change the rate of chemical reactions (B) They are reactants in chemical reactions (C) They are used up in chemical reactions (D) two of the above,A,"Catalysts interact with reactants so the reaction can occur by an alternate pathway that has a lower activation energy. Activation energy is the energy needed to start a reaction. When activation energy is lower, more reactant particles have enough energy to react so the reaction goes faster. Many catalysts work like the one in the Figure 1.1. The catalyst brings the reactants together by temporarily bonding with them. This makes it easier and quicker for the reactants to react together. Q: In the Figure 1.1, look at the energy needed in the catalytic and non-catalytic pathways of the reaction. How does the amount of energy compare? How does this affect the reaction rate along each pathway? A: The catalytic pathway of the reaction requires far less energy. Therefore, the reaction will occur faster by this pathway because more reactants will have enough energy to react. "
energy stored in chemical bonds,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,G,"Energy is stored in the bonds between atoms that make up compounds. This energy is called chemical energy, and it is a form of potential energy. If the bonds between atoms are broken, the energy is released and can do work. The wood in the fireplace in Figure 17.10 has chemical energy. The energy is released as thermal energy when the wood burns. People and many other living things meet their energy needs with chemical energy stored in food. When food molecules are broken down, the energy is released and may be used to do work. "
substance that speeds up chemical reactions,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,B,"Some reactions need extra help to occur quickly. They need another substance called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction. A catalyst isnt a reactant, so it isnt changed or used up in the reaction. Therefore, it can catalyze many other reactions. "
turning out heat,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,E,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
An endothermic chemical reaction is a reaction that releases energy.,(A) true (B) false,B,"In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. The word ""endothermic"" literally means ""taking in heat."" A constant input of energy, often in the form of heat, is needed in an endothermic reaction. Not enough energy is released when products form to break more bonds in the reactants. Additional energy is needed to keep the reaction going. The general equation for an endothermic reaction is: Reactants + Energy ! Products In many endothermic reactions, heat is absorbed from the surroundings. As a result, the temperature drops. The drop in temperature may be great enough to cause liquid products to freeze. Thats what happens in the endothermic reaction at this URL:  One of the most important endothermic reactions is photosynthesis. In this reaction, plants synthesize glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ). The energy for photo- synthesis comes from light (see Figure 8.12). Without light energy, photosynthesis cannot occur. The chemical equation for photosynthesis is: 6CO2 + 6H2 O ! C6 H12 O6 + 6O2 "
how fast a reaction occurs,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,F,How fast a chemical reaction occurs is called the reaction rate. Several factors affect the rate of a given chemical reaction. They include the: temperature of reactants. concentration of reactants. surface area of reactants. presence of a catalyst. 
The general equation for an exothermic reaction is Reactants + Energy  Products.,(A) true (B) false,B,"The word exothermic means releasing heat. Energy, often in the form of heat, is released as an exothermic reaction proceeds. This is illustrated in the Figure 1.1. The general equation for an exothermic reaction is: Reactants  Products + Energy If the energy produced in an exothermic reaction is released as heat, it results in a rise in temperature. As a result, the products are likely to be warmer than the reactants. Note: H represents the change in en- ergy. Q: You turn on the hot water faucet, and hot water pours out. How does the water get hot? Do you think that an exothermic reaction might be involved? A: A hot water heater increases the temperature of water in most homes. Many hot water heaters burn a fuel such as natural gas. The burning fuel causes the water to get hot because combustion is an exothermic reaction. "
energy needed to start a reaction,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,A,"Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas wont occur without the spark of energy to begin the reaction. Q: Why is activation energy needed? Why wont a reaction occur without it? A: A reaction wont occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. "
taking in heat,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,D,"Heat energy is transferred between physical entities. Heat is taken in or released when an object changes state, or changes from a gas to a liquid, or a liquid to a solid. This heat is called latent heat. When a substance changes state, latent heat is released or absorbed. A substance that is changing its state of matter does not change temperature. All of the energy that is released or absorbed goes toward changing the materials state. For example, imagine a pot of boiling water on a stove burner: that water is at 100o C (212o F). If you increase the temperature of the burner, more heat enters the water. The water remains at its boiling temperature, but the additional energy goes into changing the water from liquid to gas. With more heat the water evaporates more rapidly. When water changes from a liquid to a gas it takes in heat. Since evaporation takes in heat, this is called evaporative cooling. Evaporative cooling is an inexpensive way to cool homes in hot, dry areas. Substances also differ in their specific heat, the amount of energy needed to raise the temperature of one gram of the material by 1.0o C (1.8o F). Water has a very high specific heat, which means it takes a lot of energy to change the temperature of water. Lets compare a puddle and asphalt, for example. If you are walking barefoot on a sunny day, which would you rather walk across, the shallow puddle or an asphalt parking lot? Because of its high specific heat, the water stays cooler than the asphalt, even though it receives the same amount of solar radiation. "
Plants synthesize glucose in an endothermic chemical reaction.,(A) true (B) false,A,"One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6 H2 O  C6 H12 O6 + 6 O2 The energy for photosynthesis comes from light. Without light energy, photosynthesis cannot occur. As you can see in the Figure 1.2, plants can get the energy they need for photosynthesis from either sunlight or artificial light. "
number of particles of a substance in a given volume,(A) activation energy (B) catalyst (C) concentration (D) endothermic (E) exothermic (F) reaction rate (G) chemical energy,C,"Density is an important physical property of matter. It reflects how closely packed the particles of matter are. Density is calculated from the amount of mass in a given volume of matter, using the formula: Density (D) = Mass (M) Volume (V ) Problem Solving Problem: What is the density of a substance that has a mass of 20 g and a volume of 10 mL? Solution: D = 20 g/10 mL = 2.0 g/mL You Try It! Problem: An object has a mass of 180 kg and a volume of 90 m3 . What is its density? To better understand density, think about a bowling ball and a volleyball. The bowling ball feels heavy. It is solid all the way through. It contains a lot of tightly packed particles of matter. In contrast, the volleyball feels light. It is full of air. It contains fewer, more widely spaced particles of matter. Both balls have about the same volume, but the bowling ball has a much greater mass. Its matter is denser. "
The law of conservation of energy does not apply to chemical reactions.,(A) true (B) false,B,"Whether a chemical reaction absorbs or releases energy, there is no overall change in the amount of energy during the reaction. Thats because energy cannot be created or destroyed. This is the law of conservation of energy. Energy may change form during a chemical reactionfor example, from chemical energy to heat energy when gas burns in a furnacebut the same amount of energy remains after the reaction as before. This is true of all chemical reactions. Q: If energy cant be destroyed during a chemical reaction, what happens to the energy that is absorbed in an endothermic reaction? A: The energy is stored in the bonds of the products as chemical energy. In an endothermic reaction, the products have more stored chemical energy than the reactants. This is represented by the graph on the left in the Figure 1.1. In an exothermic reaction, the opposite is true. The products have less stored chemical energy than the reactants. You can see this in the graph on the right in the Figure 1.1. Note: H represents the change in en- ergy. Q: What happens to the excess energy in the reactants of an exothermic reaction? A: The excess energy is generally released to the surroundings when the reaction occurs. In a home heating system, for example, the energy that is released during combustion in the furnace is used to heat the home. "
Any factor that helps reactants come together lowers the activation energy.,(A) true (B) false,A,"Any factor that helps reactants come together so they can react lowers the amount of activation energy needed to start the reaction. If the activation energy is lowered, more reactant particles can react, and the reaction occurs more quickly. How fast a reaction occurs is called the reaction rate. Factors that affect the reaction rate include: temperature of reactants concentration of reactants surface area of reactants presence of catalysts "
All chemical reactions involve energy.,(A) true (B) false,A,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
One of the most important endothermic reactions is photosynthesis.,(A) true (B) false,A,"One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6 H2 O  C6 H12 O6 + 6 O2 The energy for photosynthesis comes from light. Without light energy, photosynthesis cannot occur. As you can see in the Figure 1.2, plants can get the energy they need for photosynthesis from either sunlight or artificial light. "
"In an exothermic reaction, it takes more energy to break bonds in reactants than is released when bonds",(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
Combustion is an example of an endothermic reaction.,(A) true (B) false,B,"All combustion reactions are exothermic reactions. During a combustion reaction, a substance burns as it combines with oxygen. When substances burn, they usually give off energy as heat and light. Look at the big bonfire in the Figure 1.2. The combustion of wood is an exothermic reaction that releases a lot of energy as heat and light. You can see the light energy the fire is giving off. If you were standing near the fire, you would also feel its heat. "
There is no overall change in the amount of energy in chemical reactions.,(A) true (B) false,A,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
Only endothermic reactions need energy to get started.,(A) true (B) false,B,"Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energy. But do exothermic reactions also need activation energy? A: All chemical reactions need energy to get started, even exothermic reactions. Look at the Figure 1.1. They compare energy changes that occur during endothermic and exothermic reactions. From the graphs, you can see that both types of reactions need the same amount of activation energy in order to get started. Only after it starts does the exothermic reaction produce more energy than it uses. "
Energy is absorbed in exothermic reactions.,(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
An increase in temperature is a sign of an exothermic reaction.,(A) true (B) false,A,"The word exothermic means releasing heat. Energy, often in the form of heat, is released as an exothermic reaction proceeds. This is illustrated in the Figure 1.1. The general equation for an exothermic reaction is: Reactants  Products + Energy If the energy produced in an exothermic reaction is released as heat, it results in a rise in temperature. As a result, the products are likely to be warmer than the reactants. Note: H represents the change in en- ergy. Q: You turn on the hot water faucet, and hot water pours out. How does the water get hot? Do you think that an exothermic reaction might be involved? A: A hot water heater increases the temperature of water in most homes. Many hot water heaters burn a fuel such as natural gas. The burning fuel causes the water to get hot because combustion is an exothermic reaction. "
Products have less stored chemical energy than reactants in an endothermic reaction.,(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called endothermic reactions, less energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of exothermic reactions. In an exothermic reaction, it takes less energy to break bonds in the reactants than is released when new bonds form in the products. "
Catalysts in living things are called enzymes.,(A) true (B) false,A,"Chemical reactions constantly occur inside the cells of living things. However, under the conditions inside cells, most biochemical reactions would occur too slowly to maintain life. Thats where enzymes come in. Enzymes are catalysts in living things. Like other catalysts, they speed up chemical reactions. Enzymes are proteins that are synthesized in the cells that need them, based on instructions encoded in the cells DNA. "
Cellulose is,(A) one of the most common compounds on Earth (B) made by the cells of plants and animals (C) a monomer of carbon (D) all of the above,A,"Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. "
How many more valence electrons does carbon need to fill its outer energy level?,(A) 1 (B) 2 (C) 3 (D) 4,D,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 elements, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in the electron dot diagram in the Figure 1.1. Q: How many more electrons does carbon need to have a full outer energy level? A: Carbon needs four more valence electrons, or a total of eight valence electrons, to fill its outer energy level. A full outer energy level is the most stable arrangement of electrons. Q: How can carbon achieve a full outer energy level? A: Carbon can form four covalent bonds. Covalent bonds are chemical bonds that form between nonmetals. In a covalent bond, two atoms share a pair of electrons. By forming four covalent bonds, carbon shares four pairs of electrons, thus filling its outer energy level and achieving stability. "
Which type(s) of bonds can a carbon atom form with other carbon atoms?,(A) single bonds (B) double bonds (C) triple bonds (D) all of the above,D,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
How many bonds can each carbon atom form?,(A) 1 (B) 2 (C) 3 (D) 4,D,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
Forms of pure carbon include,(A) methane (B) cellulose (C) diamond (D) two of the above,C,"Pure carbon can exist in different forms, depending on how its atoms are arranged. The forms include diamond, graphite, and fullerenes. All three forms exist as crystals, but they have different structures. Their different structures, in turn, give them different properties. You can learn more about them in Table 9.1. atoms affect the properties of the substances formed? Structure Diamond crystal Description Diamond Diamond is a form of carbon in which each carbon atom is bonded to four other carbon atoms. This forms a strong, rigid, three- dimensional structure. Diamond is the hardest natural substance. It is used for cutting and grinding tools as well as for rings and other pieces of jewelry. Graphite Graphite is a form of carbon in which carbon atoms are arranged in layers. Bonds are strong between carbon atoms within each layer but relatively weak between atoms in different layers. The weak bonds between layers allow the layers to slide over one another. This makes graphite relatively soft and slippery. It is used as a lubricant. It also makes up the ""lead"" in pencils. Fullerene A fullerene (also called a bucky- ball) is a form of carbon in which carbon atoms are arranged in hol- low spheres. Each carbon atom is bonded to three others by sin- gle covalent bonds. The pattern of atoms resembles the pattern on the surface of a soccer ball. Fullerenes were first discovered in 1985. They have been found in soot and me- teorites. Possible commercial uses of fullerenes are under investiga- tion. To learn how this form of carbon got its funny names, go to this URL:  This metal cutter has a diamond blade. "
The plastic called polythene consists of,(A) repeating monomers of ethene (B) only carbon and hydrogen atoms (C) many fullerenes joined by covalent bonds (D) two of the above,D,Synthetic carbon polymers are produced in labs or factories. Plastics are common examples of synthetic carbon polymers. You are probably familiar with the plastic called polyethylene. All of the plastic items pictured in the Figure 1.3 are made of polyethylene. It consists of repeating monomers of ethylene (C2 H4 ). Structural formulas for ethylene and polyethylene are also shown in the Figure 1.4. Click image to the left or use the URL below. URL: 
Forms of crystalline carbon include,(A) cotton (B) graphite (C) charcoal (D) methane,B,"Graphite is one of three forms of crystalline, or crystal-forming, carbon. Carbon also exists in an amorphous, or shapeless, form in substances such as coal and charcoal. Different forms of the same element are called allotropes. Besides graphite, the other allotropes of crystalline carbon are diamond and fullerenes. All three forms exist as crystals rather than molecules. In a crystal, many atoms are bonded together in a repeating pattern that may contains thousands of atoms. The arrangement of atoms in the crystal differs for each form of carbon and explains why the different forms have different properties. Click image to the left or use the URL below. URL:  Q: How do you think the properties of diamond might differ from the properties of graphite? A: Diamond is clear whereas graphite is black. Diamond is also very hard, so it doesnt break easily. Graphite, in contrast, is soft and breaks very easily. "
One of the most common naturally occurring compounds on Earth is,(A) graphite (B) fullerene (C) cellulose (D) polythene,C,An element is a pure substance. It cannot be separated into any other substances. There are more than 90 different elements that occur in nature. Some are much more common than others. Hydrogen is the most common element in the universe. Oxygen is the most common element in Earths crust. Figure 3.7 shows other examples of elements. Still others are described in the video below. MEDIA Click image to the left or use the URL below. URL: 
The monomers in a polymer may be,(A) all the same (B) different from one another (C) joined by metallic bonds (D) two of the above,D,"Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers. (The prefix mono- means one and the prefix poly- means many.) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure 1.1. Like beads on a string, monomers in a polymer may be all the same or different from one another. "
Which statement about carbon is false?,(A) It has four valence electrons (B) It forms covalent bonds with other nonmetals (C) It is found in the majority of known compounds (D) It rarely forms large compounds called polymers,D,The short term cycling of carbon begins with carbon dioxide (CO2 ) in the atmosphere. 
All carbon polymers are,(A) naturally occurring (B) produced in labs (C) found in plastics (D) large molecules,D,"Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers. (The prefix mono- means one and the prefix poly- means many.) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure 1.1. Like beads on a string, monomers in a polymer may be all the same or different from one another. "
large molecule that consists of many smaller molecules joined together by covalent bonds,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,B,"Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers. (The prefix mono- means one and the prefix poly- means many.) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure 1.1. Like beads on a string, monomers in a polymer may be all the same or different from one another. "
form of carbon in which carbon atoms are arranged in layers,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,F,"Pure carbon can exist in different forms, depending on how its atoms are arranged. The forms include diamond, graphite, and fullerenes. All three forms exist as crystals, but they have different structures. Their different structures, in turn, give them different properties. You can learn more about them in Table 9.1. atoms affect the properties of the substances formed? Structure Diamond crystal Description Diamond Diamond is a form of carbon in which each carbon atom is bonded to four other carbon atoms. This forms a strong, rigid, three- dimensional structure. Diamond is the hardest natural substance. It is used for cutting and grinding tools as well as for rings and other pieces of jewelry. Graphite Graphite is a form of carbon in which carbon atoms are arranged in layers. Bonds are strong between carbon atoms within each layer but relatively weak between atoms in different layers. The weak bonds between layers allow the layers to slide over one another. This makes graphite relatively soft and slippery. It is used as a lubricant. It also makes up the ""lead"" in pencils. Fullerene A fullerene (also called a bucky- ball) is a form of carbon in which carbon atoms are arranged in hol- low spheres. Each carbon atom is bonded to three others by sin- gle covalent bonds. The pattern of atoms resembles the pattern on the surface of a soccer ball. Fullerenes were first discovered in 1985. They have been found in soot and me- teorites. Possible commercial uses of fullerenes are under investiga- tion. To learn how this form of carbon got its funny names, go to this URL:  This metal cutter has a diamond blade. "
one of the simplest carbon compounds,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,E,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
form of carbon that it is the hardest natural substance,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,D,"Diamond is a form of carbon in which each carbon atom is covalently bonded to four other carbon atoms. This forms a strong, rigid, three-dimensional structure (see Figure 1.1). Diamond is the hardest natural substance, and no other natural substance can scratch it. This property makes diamonds useful for cutting and grinding tools as well as for rings and other jewelry (see Figure 1.2). "
Carbon is a nonmetal in group 12 of the periodic table.,(A) true (B) false,B,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
small molecule joined with other small molecules by covalent bonds to form a much larger molecule,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,A,"Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers. (The prefix mono- means one and the prefix poly- means many.) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure 1.1. Like beads on a string, monomers in a polymer may be all the same or different from one another. "
A structural formula uses dots to represent electrons.,(A) true (B) false,B,"Because valence electrons are so important, atoms are often represented by simple diagrams that show only their valence electrons. These are called electron dot diagrams, and three are shown below. In this type of diagram, an elements chemical symbol is surrounded by dots that represent the valence electrons. Typically, the dots are drawn as if there is a square surrounding the element symbol with up to two dots per side. An element never has more than eight valence electrons, so there cant be more than eight dots per atom. Q: Carbon (C) has four valence electrons. What does an electron dot diagram for this element look like? A: An electron dot diagram for carbon looks like this: "
form of carbon in which carbon atoms are arranged in hollow spheres,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,G,"A fullerene (also called a Bucky ball) is a form of carbon in which carbon atoms are arranged in a hollow sphere resembling a soccer ball (see Figure 1.4). Each sphere contains 60 carbon atoms, and each carbon atom is bonded to three others by single covalent bonds. The bonds are relatively weak, so fullerenes can dissolve and form solutions. Fullerenes were first discovered in 1985 and have been found in soot and meteorites. Possible commercial uses of fullerenes are under investigation. Fullerene Crystal "
All carbon polymers are made in labs or factories.,(A) true (B) false,B,Synthetic carbon polymers are produced in labs or factories. Plastics are common examples of synthetic carbon polymers. You are probably familiar with the plastic called polyethylene. All of the plastic items pictured in the Figure 1.3 are made of polyethylene. It consists of repeating monomers of ethylene (C2 H4 ). Structural formulas for ethylene and polyethylene are also shown in the Figure 1.4. Click image to the left or use the URL below. URL: 
carbon compound found only in plants,(A) monomer (B) polymer (C) cellulose (D) diamond (E) methane (F) graphite (G) fullerene,C,"The element carbon is the basis of all life on Earth. Biochemical compounds consist of chains of carbon atoms and just a few other elements. Like water, carbon is constantly recycled through the biotic and abiotic factors of ecosystems. The carbon cycle includes carbon in sedimentary rocks and fossil fuels under the ground, the ocean, the atmosphere, and living things. The diagram in Figure 24.9 represents the carbon cycle. It shows some of the ways that carbon moves between the different parts of the cycle. You can see an animated carbon cycle at this link: http://commons.w "
Graphite is used as a lubricant because it is slippery.,(A) true (B) false,A,"Graphite is a form of crystalline carbon in which each carbon atom is covalently bonded to three other carbon atoms. The carbon atoms are arranged in layers, with strong bonds within each layer but only weak bonds between layers (see Figure 1.3). The weak bonds between layers allow the layers to slide over one another, so graphite is relatively soft and slippery. This makes it useful as a lubricant. Q: Why do graphites properties make it useful for pencil leads? A: Being slippery, graphite slides easily over paper when you write. Being soft, it rubs off on the paper, allowing you to leave marks. Graphites softness also allows you to sharpen it easily. (Imagine trying to sharpen a diamond!) "
Each molecule of methane contains four atoms of carbon.,(A) true (B) false,B,"A carbon atom can form covalent bonds with other carbon atoms or with the atoms of other elements. Carbon often forms bonds with hydrogen. Compounds that contain only carbon and hydrogen are called hydrocarbons. Methane (CH4 ), which is modeled in the Figure 1.2, is an example of a hydrocarbon. In methane, a single carbon atom forms covalent bonds with four hydrogen atoms. The diagram on the left in the Figure 1.2 shows all the shared valence electrons. The diagram on the right in the Figure 1.2, called a structural formula, represents each pair of shared electrons with a dash (-). Methane (CH4 ) "
The chief component of cellulose is carbon.,(A) true (B) false,A,"Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. "
Carbon forms more compounds than any other element.,(A) true (B) false,A,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
Carbon can form bonds with any other element except itself.,(A) true (B) false,B,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
The carbon compound with the formula CH4 is polyethylene.,(A) true (B) false,B,Synthetic carbon polymers are produced in labs or factories. Plastics are common examples of synthetic carbon polymers. You are probably familiar with the plastic called polyethylene. All of the plastic items pictured in the Figure 1.3 are made of polyethylene. It consists of repeating monomers of ethylene (C2 H4 ). Structural formulas for ethylene and polyethylene are also shown in the Figure 1.4. Click image to the left or use the URL below. URL: 
"In a triple bond, two atoms share three valence electrons.",(A) true (B) false,B,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
Plastics are examples of synthetic carbon polymers.,(A) true (B) false,A,Synthetic carbon polymers are produced in labs or factories. Plastics are common examples of synthetic carbon polymers. You are probably familiar with the plastic called polyethylene. All of the plastic items pictured in the Figure 1.3 are made of polyethylene. It consists of repeating monomers of ethylene (C2 H4 ). Structural formulas for ethylene and polyethylene are also shown in the Figure 1.4. Click image to the left or use the URL below. URL: 
All forms of crystalline carbon have the same structure.,(A) true (B) false,B,"Graphite is one of three forms of crystalline, or crystal-forming, carbon. Carbon also exists in an amorphous, or shapeless, form in substances such as coal and charcoal. Different forms of the same element are called allotropes. Besides graphite, the other allotropes of crystalline carbon are diamond and fullerenes. All three forms exist as crystals rather than molecules. In a crystal, many atoms are bonded together in a repeating pattern that may contains thousands of atoms. The arrangement of atoms in the crystal differs for each form of carbon and explains why the different forms have different properties. Click image to the left or use the URL below. URL:  Q: How do you think the properties of diamond might differ from the properties of graphite? A: Diamond is clear whereas graphite is black. Diamond is also very hard, so it doesnt break easily. Graphite, in contrast, is soft and breaks very easily. "
Carbon can combine only with hydrogen and oxygen.,(A) true (B) false,B,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
Carbon forms ionic bonds with other nonmetals.,(A) true (B) false,B,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
There are millions of known carbon compounds.,(A) true (B) false,A,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
Which statement about hydrocarbons is true?,(A) They are the most complex type of carbon compounds (B) They are all gases at room temperature (C) They generally do not dissolve in water (D) none of the above,C,"Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds. Nonetheless, they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms, but large hydrocarbons may have hundreds. The size of hydrocarbon molecules influences their properties. For example, it influences their boiling and melting points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar and do not dissolve in water. In fact, they tend to repel water. Thats why they are used in floor wax and similar products. Hydrocarbons can be classified in two basic classes. The classes are saturated hydrocarbons and unsaturated hydrocarbons. This classification is based on the number of bonds between carbon atoms. You can learn more about both types of hydrocarbons at this URL:  (6:41). MEDIA Click image to the left or use the URL below. URL: "
Which statement about hydrocarbons is false?,(A) All of them are polar compounds (B) Most of them are obtained from fossil fuels (C) Some of them are solids at room temperature (D) They are the simplest type of carbon compounds,A,"Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds, but they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms. The largest hydrocarbons may have thousands of carbon atoms. Q: How are hydrocarbons involved in each of the photos pictured above? A: The main ingredient of mothballs is the hydrocarbon naphthalene. The main ingredient in nail polish remover is the hydrocarbon acetone. The lawn mower runs on a mixture of hydrocarbons called gasoline, and the camp stove burns a hydrocarbon fuel named isobutane. "
The simplest hydrocarbons are,(A) unsaturated hydrocarbons (B) saturated hydrocarbons (C) aromatic hydrocarbons (D) alkenes and alkynes,B,"Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds, but they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms. The largest hydrocarbons may have thousands of carbon atoms. Q: How are hydrocarbons involved in each of the photos pictured above? A: The main ingredient of mothballs is the hydrocarbon naphthalene. The main ingredient in nail polish remover is the hydrocarbon acetone. The lawn mower runs on a mixture of hydrocarbons called gasoline, and the camp stove burns a hydrocarbon fuel named isobutane. "
The last part of the name of a hydrocarbon compound indicates,(A) the number of bonds between carbon atoms (B) the number of carbon atoms per molecule (C) the shape of the hydrocarbon compound (D) none of the above,A,"Saturated hydrocarbons are given the general name of alkanes. The name of specific alkanes always ends in -ane. The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table 1.1. The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures. Alkane Methane Ethane Propane Butane Pentane Hexane Heptane Octane Chemical Formula CH4 C2 H6 C3 H8 C4 H10 C5 H12 C6 H14 C7 H16 C8 H18 Boiling Point( C) -162 -89 -42 0 36 69 98 126 Melting Point( C) -183 -172 -188 -138 -130 -95 -91 -57 State (at 20  C) gas gas gas gas liquid liquid liquid liquid Q: The Table 1.1 shows only alkanes that have relatively few carbon atoms. Some alkanes have many more carbon atoms. What properties might larger alkanes have? A: Alkanes with more carbon atoms have higher boiling and melting points, so some of them are solids at room temperature. "
The first part of the name of a hydrocarbon indicates the number of,(A) bonds between carbon atoms (B) branches in the molecule (C) hydrogen atoms (D) carbon atoms,D,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
Hydrocarbons are used in floor wax because they,(A) resist scratches (B) tend to repel water (C) dissolve well in water (D) have high melting points,B,"The size of hydrocarbon molecules influences their properties, including their melting and boiling points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar, which means that their molecules do not have oppositely charged sides. Therefore, they do not dissolve in water, which is a polar compound. In fact, hydrocarbons tend to repel water. Thats why they are used in floor wax and similar products. "
Which of the following is an example of an unsaturated hydrocarbon?,(A) methene (B) pentane (C) propane (D) ethene,D,"Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. "
Alkanes with more carbon atoms generally have,(A) higher boiling points (B) lower boiling points (C) higher melting points (D) two of the above,D,"Saturated hydrocarbons are given the general name of alkanes. The name of specific alkanes always ends in -ane. The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table 1.1. The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures. Alkane Methane Ethane Propane Butane Pentane Hexane Heptane Octane Chemical Formula CH4 C2 H6 C3 H8 C4 H10 C5 H12 C6 H14 C7 H16 C8 H18 Boiling Point( C) -162 -89 -42 0 36 69 98 126 Melting Point( C) -183 -172 -188 -138 -130 -95 -91 -57 State (at 20  C) gas gas gas gas liquid liquid liquid liquid Q: The Table 1.1 shows only alkanes that have relatively few carbon atoms. Some alkanes have many more carbon atoms. What properties might larger alkanes have? A: Alkanes with more carbon atoms have higher boiling and melting points, so some of them are solids at room temperature. "
Aromatic hydrocarbons generally have,(A) a strong scent (B) rings of four carbon atoms (C) alternating double and triple bonds (D) all of the above,A,"Unsaturated cyclic hydrocarbons are called aromatic hydrocarbons. Thats because they have a strong aroma, or scent. Their molecules consist of six carbon atoms in a ring shape, connected by alternating single and double bonds. Aromatic hydrocarbons may have a single ring or multiple rings joined together by bonds between their carbon atoms. Benzene is the smallest aromatic hydrocarbon. It has just one ring. You can see its structural formula in Figure 9.14. Benzene has many uses. For example, it is used in air fresheners and mothballs because of its strong scent. You can learn more about benzene and other aromatic hydrocarbons at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Dead organisms in ancient seas gradually formed deposits of,(A) coal (B) petroleum (C) natural gas (D) two of the above,D,"Quick burial is essential because most decay and fragmentation occurs at the surface. Marine animals that die near a river delta may be rapidly buried by river sediments. A storm at sea may shift sediment on the ocean floor, covering a body and helping to preserve its skeletal remains (Figure 1.5). This fish was quickly buried in sediment to become a fossil. Quick burial is rare on land, so fossils of land animals and plants are less common than marine fossils. Land People buried by the extremely hot eruption of ash and gases at Mt. Vesuvius in 79 AD. "
Hydrocarbon compounds that are burned for fuels include,(A) coal (B) propane (C) kerosene (D) all of the above,D,"It is hard to overstate the importance of hydrocarbons to modern life. Hydrocarbons have even been called the driving force of western civilization. You saw some ways they are used in Figure 9.6. Several other ways are illustrated in Figure 9.15. Their most important use is as fuels. Gasoline, natural gas, fuel oil, diesel fuel, jet fuel, coal, kerosene, and propane are just some of the hydrocarbon compounds that are burned for fuel. Hydrocarbons are also used to manufacture many products, including plastics and synthetic fabrics such as polyester. The main source of hydrocarbons is fossil fuels coal, petroleum, and natural gas. Fossil fuels form over hundreds of millions of years when dead organisms are covered with sediments and put under great pressure. Giant ferns in ancient swamps turned into coal deposits. Dead organisms in ancient seas gradually formed deposits of petroleum and natural gas. You can read more about these sources of hydrocarbons in the chapter Introduction to Energy and at the URL below. "
Fossil fuels include,(A) wood (B) charcoal (C) petroleum (D) all of the above,C,"Fossil fuels are mixtures of hydrocarbons that formed over millions of years from the remains of dead organisms. They include petroleum (commonly called oil), natural gas, and coal. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes. You can see examples of their use in Figure 17.19. Fossil fuels contain stored chemical energy that came originally from the sun. Ancient plants changed energy in "
All hydrocarbons are small chemical compounds.,(A) true (B) false,B,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
Hydrocarbons are generally nonpolar compounds.,(A) true (B) false,A,"The size of hydrocarbon molecules influences their properties, including their melting and boiling points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar, which means that their molecules do not have oppositely charged sides. Therefore, they do not dissolve in water, which is a polar compound. In fact, hydrocarbons tend to repel water. Thats why they are used in floor wax and similar products. "
Isomers of a given compound always have the same properties.,(A) true (B) false,B,"Even compounds with the same number of carbon and hydrogen atoms can have different shapes. These compounds are called isomers. Look at the examples in Figure 9.9. The figure shows the structural formulas of butane and its isomer iso-butane. Both molecules have four carbon atoms and ten hydrogen atoms (C4 H10 ), but the atoms are arranged differently. Butane is a straight-chain molecule. Iso-butane is branched. You can see three-dimensional models of these two isomers at the URLs below. You can rotate the molecule models to get a better idea of their shapes. "
Hydrocarbons are compounds that contain only carbon and hydrogen.,(A) true (B) false,A,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
Heptane is an unsaturated hydrocarbon.,(A) true (B) false,B,"Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. "
The simplest hydrocarbons are the aromatic hydrocarbons.,(A) true (B) false,B,"Unsaturated hydrocarbons called aromatic hydrocarbons are cyclic hydrocarbons that have double bonds. These compounds have six carbon atoms in a ring with alternating single and double bonds. The smallest aromatic hydrocarbon is benzene, which has just one ring. Its structural formula is shown in the Figure 1.2. Larger aromatic hydrocarbons consist of two or more rings, which are joined together by bonds between their carbon atoms. The name of aromatic hydrocarbons comes from their strong aroma, or scent. Thats why they are used in air fresheners and mothballs. A: Each carbon atom forms four covalent bonds. Carbon atoms always form four covalent bonds, regardless of the atoms to which it bonds. "
Butane has branched-chain molecules.,(A) true (B) false,B,"Even compounds with the same number of carbon and hydrogen atoms can have different shapes. These compounds are called isomers. Look at the examples in Figure 9.9. The figure shows the structural formulas of butane and its isomer iso-butane. Both molecules have four carbon atoms and ten hydrogen atoms (C4 H10 ), but the atoms are arranged differently. Butane is a straight-chain molecule. Iso-butane is branched. You can see three-dimensional models of these two isomers at the URLs below. You can rotate the molecule models to get a better idea of their shapes. "
The size of hydrocarbon molecules influences their properties.,(A) true (B) false,A,"The size of hydrocarbon molecules influences their properties, including their melting and boiling points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar, which means that their molecules do not have oppositely charged sides. Therefore, they do not dissolve in water, which is a polar compound. In fact, hydrocarbons tend to repel water. Thats why they are used in floor wax and similar products. "
Butane and iso-butane differ in their number of hydrogen atoms.,(A) true (B) false,B,"Even compounds with the same number of carbon and hydrogen atoms can have different shapes. These compounds are called isomers. Look at the examples in Figure 9.9. The figure shows the structural formulas of butane and its isomer iso-butane. Both molecules have four carbon atoms and ten hydrogen atoms (C4 H10 ), but the atoms are arranged differently. Butane is a straight-chain molecule. Iso-butane is branched. You can see three-dimensional models of these two isomers at the URLs below. You can rotate the molecule models to get a better idea of their shapes. "
Any hydrocarbon ending in ane has only straight-chain molecules.,(A) true (B) false,B,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
Alkenes may form straight or branchedchains but not rings.,(A) true (B) false,B,"Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced by most fruits and vegetables. It speeds up ripening and also rotting. Figure 9.11 shows the effects of ethene on bananas. Like alkanes, alkenes can have different shapes. They can form straight chains, branched chains, or rings. Alkenes can also form isomers, or compounds with the same atoms but different shapes. Generally, the physical properties of alkenes are similar to those of alkanes. Smaller alkenes, such as ethene, have relatively high boiling and melting points. They are gases at room temperature. Larger alkenes have lower boiling and melting points. They are liquids or waxy solids at room temperature. "
Hydrocarbons are used to make synthetic fabrics such as polyester.,(A) true (B) false,A,"It is hard to overstate the importance of hydrocarbons to modern life. Hydrocarbons have even been called the driving force of western civilization. You saw some ways they are used in the opening image. Several other ways are pictured in the Figure 1.1. The most important use of hydrocarbons is for fuel. Gasoline, natural gas, fuel oil, diesel fuel, jet fuel, coal, kerosene, and propane are just some of the commonly used hydrocarbon fuels. Hydrocarbons are also used to make things, including plastics and synthetic fabrics such as polyester. Motor oil: Motor oil consists of several hydrocarbons. It lubricates the moving parts of car engines. Asphalt: Asphalt pavement on highways is made of hy- drocarbons found in petroleum. Candle: Many candles are made of paraffin wax, a solid mixture of hydrocarbons. Lighter: This lighter burns the hydrocarbon named butane. Rain Boots: These rain boots are made of a mixture of several hydro- carbons. Transportation: These forms of transportation are fueled by different mixtures of hydrocarbons. "
The physical properties of alkenes are generally similar to those of alkanes.,(A) true (B) false,A,"Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced by most fruits and vegetables. It speeds up ripening and also rotting. Figure 9.11 shows the effects of ethene on bananas. Like alkanes, alkenes can have different shapes. They can form straight chains, branched chains, or rings. Alkenes can also form isomers, or compounds with the same atoms but different shapes. Generally, the physical properties of alkenes are similar to those of alkanes. Smaller alkenes, such as ethene, have relatively high boiling and melting points. They are gases at room temperature. Larger alkenes have lower boiling and melting points. They are liquids or waxy solids at room temperature. "
Alkynes are relatively rare in nature.,(A) true (B) false,A,"Unsaturated hydrocarbons that contain at least one triple bond are called alkynes. The name of specific alkynes always end in yne, with a prefix for the number of carbon atoms. Figure 9.12 shows the smallest alkyne, called ethyne, which has just two carbon atoms. Ethyne is also called acetylene. It is burned in acetylene torches, like the one in Figure 9.13. Acetylene produces so much heat when it burns that it can melt metal. Breaking all those bonds between carbon atoms releases a lot of energy. Alkynes may form straight or branched chains. They rarely occur as cycloalkynes. In fact, alkynes of all shapes are relatively rare, at least in nature. "
Fossil fuels formed over millions of years from dead organisms.,(A) true (B) false,A,"Fossil fuels are made from plants and animals that lived hundreds of millions of years ago. The plants and animals died. Their remains settled onto the ground and at the bottom of the sea. Layer upon layer of organic material was laid down. Eventually, the layers were buried very deeply. They experienced intense heat and pressure. Over millions of years, the organic material turned into fossil fuels. Fossil fuels are compounds of carbon and hydrogen, called hydrocarbons. Hydrocarbons can be solid, liquid, or gas. The solid form is coal. The liquid form is petroleum, or crude oil. The gaseous form is natural gas. "
Ring-shaped unsaturated hydrocarbons,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,F,"Ring-shaped alkanes are called cycloalkanes. They usually contain just five or six carbon atoms because larger rings are not very stable. However, rings can join together to create larger molecules consisting of two or more rings. Compared with the straight- and branched-chain alkanes, cycloalkanes have higher boiling and melting points. "
all compounds that consist only of carbon and hydrogen,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,D,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
unsaturated hydrocarbons with at least one double bond,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,B,"Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. "
ring-shaped saturated hydrocarbons,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,G,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
saturated hydrocarbons such as ethane,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,A,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
molecules with the same atoms but different shapes,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,E,"Even compounds with the same number of carbon and hydrogen atoms can have different shapes. These compounds are called isomers. Look at the examples in Figure 9.9. The figure shows the structural formulas of butane and its isomer iso-butane. Both molecules have four carbon atoms and ten hydrogen atoms (C4 H10 ), but the atoms are arranged differently. Butane is a straight-chain molecule. Iso-butane is branched. You can see three-dimensional models of these two isomers at the URLs below. You can rotate the molecule models to get a better idea of their shapes. "
unsaturated hydrocarbons with at least one triple bond,(A) alkanes (B) alkenes (C) alkynes (D) hydrocarbons (E) isomers (F) aromatic hydrocarbons (G) cycloalkanes,C,"Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. "
Classes of biochemical compounds include all of the following except,(A) lipids (B) proteins (C) phosphates (D) nucleic acids,C,"Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element. "
Living things use lipids for,(A) energy (B) enzymes (C) cell membranes (D) two of the above,D,"Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. "
Functions of proteins include,(A) coding genetic information (B) storing energy in animals (C) regulating life processes (D) making up cell walls,C,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
Which statement about RNA is true?,(A) It has a double helix shape (B) It consists of two chains of nucleotides (C) It is needed for the synthesis of proteins (D) It contains the nitrogen base called thymine,C,"RNA stands for ribonucleic acid. RNA is smaller than DNA. It can squeeze through pores in the membrane that encloses the nucleus. It copies instructions in DNA and carries them to a ribosome in the cytoplasm. Then it helps build the protein. RNA is not only smaller than DNA. It differs from DNA in other ways as well. It consists of one nucleotide chain rather than two chains as in DNA. It also contains the nitrogen base uracil (U) instead of thymine (T). In addition, it contains the sugar ribose instead of deoxyribose. You can see these differences in Figure 5.16. "
A nucleotide consists of a,(A) phosphate group (B) nitrogen base (C) sugar (D) all of the above,D,"Nucleotides are composed of three main parts: 1. a phosphate group. 2. a 5-carbon sugar (deoxyribose in DNA). 3. a nitrogen-containing base. The only difference between each nucleotide is the identity of the base. There are only four possible bases that make up each DNA nucleotide: adenine (A), guanine (G), thymine (T), and cytosine (C). "
All biochemical compounds contain hydrogen.,(A) true (B) false,A,"You can see from Table 2.1 that all biochemical compounds contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Most biochemical molecules are macromolecules. The prefix macro- means large, and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. The largest known biochemical molecule contains more than 34,000 monomers! "
There are a total of 20 different biochemical compounds.,(A) true (B) false,B,"Biochemical compounds make up the cells and tissues of living things. They are also involved in all life processes. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. Even so, all biochemical compounds can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 2.1. Class Elements Examples Functions Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starch glycogen cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids fats oils phospholipids DNA RNA Functions provide energy to cells stores energy in plants stores energy in animals makes up the cell walls of plants speed up biochemical re- actions regulate life processes store energy in animals store energy in plants make up cell membranes stores genetic information in cells helps cells make proteins "
Some nucleic acids are hormones that regulate life processes.,(A) true (B) false,B,"Nucleic acids are long chains of nucleotides. Nucleotides are made of a sugar, a nitrogen-containing base, and a phosphate group. Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) are the two main nucleic acids. DNA is a double-stranded nucleic acid. DNA is the molecule that stores our genetic information ( Figure 1.6). The single- stranded RNA is involved in making proteins. ATP (adenosine triphosphate), known as the ""energy currency"" of the cell, is also a nucleic acid. "
Biochemical compounds are carbon-based compounds found in living things.,(A) true (B) false,A,"Besides water, most of the compounds in living things are biochemical compounds. A biochemical compound is a carbon-based compound that is found in living organisms. Carbon is an element that has a tremendous ability to form large compounds. Each atom of carbon can form four chemical bonds with other atoms. A chemical bond is the sharing of electrons between atoms. Bonds hold the atoms together in chemical compounds. A carbon atom can form bonds with other carbon atoms or with atoms of other elements. "
The simplest sugar is named sucrose.,(A) true (B) false,B,"Sugars are simple carbohydrates. Molecules of sugar have just a few carbon atoms. The simplest sugar is glucose (C6 H12 O6 ). Glucose is the sugar that the cells of living things use for energy. Plants and some other organisms make glucose in the process of photosynthesis. Living things that cannot make glucose obtain it by consuming plants or these other organisms. You can see the structural formula of glucose and two other sugars in Figure 9.16. The other sugars in the figure are fructose and sucrose. Fructose is an isomer of glucose. It is found in fruits. It has the same atoms as glucose, but they are arranged differently. Sucrose is table sugar. It consists of one molecule of glucose and one molecule of fructose. "
The main function of simple carbohydrates is to store energy in animals.,(A) true (B) false,B,"Carbohydrates are sugars, or long chains of sugars. An important role of carbohydrates is to store energy. Glucose ( Figure 1.1) is an important simple sugar molecule with the chemical formula C6 H12 O6 . Simple sugars are known as monosaccharides. Carbohydrates also include long chains of connected sugar molecules. These long chains often consist of hundreds or thousands of monosaccharides bonded together to form polysaccharides. Plants store sugar in polysaccharides called starch. Animals store sugar in polysaccharides called glycogen. You get the carbohydrates you need for energy from eating carbohydrate-rich foods, including fruits and vegetables, as well as grains, such as bread, rice, or corn. A molecule of glucose, a type of carbohy- drate. "
Bread is a good source of starch in the diet.,(A) true (B) false,A,"Starch is a large, complex carbohydrate made of thousands of glucose units (monomers) joined together. Starches are found in foods such as vegetables and grains. Starches are broken down by the body into sugars that provide energy. Breads and pasta are good sources of complex carbohydrates. Fiber is another type of large, complex carbohydrate that is partly indigestible. Unlike sugars and starches, fiber does not provide energy. However, it has other important roles in the body. For example, fiber is important for maintaining the health of your gastrointestinal tract. Eating foods high in fiber also helps fill you up without providing too many calories. Most fruits and vegetables are high in fiber. Some examples are pictured below ( Figure 1.2). "
We need oils to help move food wastes through the digestive tract.,(A) true (B) false,B,Some substances in food cant be broken down into nutrients. They remain behind in the digestive system after the nutrients have been absorbed. Any substances in food that cant be digested pass out of the body as solid waste. This process is called elimination. 
The only biochemical compounds that contains sulfur are nucleic acids.,(A) true (B) false,B,"Nucleic acids are one of four classes of biochemical compounds. (The other three classes are carbohydrates, proteins, and lipids.) Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus. Q: Which of the elements in DNA is not identified with any other class of biochemical compounds? A: All biochemical compounds contain carbon, hydrogen, and oxygen; and proteins as well as nucleic acids contain nitrogen. Phosphorus is the only element that is identified with nucleic acids. "
Hemoglobin is a protein that fights infections in the blood.,(A) true (B) false,B,"Hemoglobin is a compound in the class of compounds called proteins. Proteins are one of four classes of biochemi- cal compounds, which are compounds in living things. (The other three classes are carbohydrates, lipids, and nucleic acids.) Proteins contain carbon, hydrogen, oxygen, nitrogen, and sulfur. Protein molecules consist of one or more chains of small molecules called amino acids. "
The most abundant biochemical compound is cellulose.,(A) true (B) false,A,"Cellulose is another complex carbohydrate that is a polymer of glucose. However, the glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers (see Figure 9.18). Have you ever eaten raw celery? If you have, then you probably noticed that the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to trunks and stems. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. "
Hemoglobin transports oxygen through the blood.,(A) true (B) false,A,"Red blood cells (RBCs) are flattened, disk-shaped cells that carry oxygen. They are the most common blood cell in the blood. There are about 4 to 6 million RBCs per cubic millimeter of blood. Each RBC has about 200 million molecules of hemoglobin. Hemoglobin is the protein that carries oxygen. Hemoglobin also gives the red blood cells their red color. Red blood cells ( Figure 1.2) are made in the red marrow of long bones, rib bones, the skull, and vertebrae. Each red blood cell lives for only 120 days (about four months). After this time, they are destroyed in the liver and spleen. Mature red blood cells do not have a nucleus or other organelles. Lacking these components allows the cells to have more hemoglobin and carry more oxygen. The flattened shape of red blood cells helps them carry more oxygen than if they were rounded. "
Muscle tissues are composed mainly of fatty acids.,(A) true (B) false,B,"Muscles are the main organs of the muscular system. Muscles are composed primarily of cells called muscle fibers. A muscle fiber is a very long, thin cell, as you can see in Figure 16.16. It contains multiple nuclei and many mitochondria, which produce ATP for energy. It also contains many organelles called myofibrils. Myofibrils allow muscles to contract, or shorten. Muscle contractions are responsible for virtually all the movements of the body, both inside and out. "
Organisms use lipids mainly to store energy.,(A) true (B) false,A,"Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. "
There are two main types of nucleic acids.,(A) true (B) false,A,"Nucleic acids are biochemical molecules that contain oxygen, nitrogen, and phosphorus in addition to carbon and hydrogen. There are two main types of nucleic acids. They are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). "
long carbon chains found in lipids,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,F,"Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, the carbons are saturated with hydrogen atoms. Saturated fatty acids are found in fats. Fats are solid lipids that animals use to store energy. In unsaturated fatty acids, there is at least one double bond between carbon atoms. As a result, some carbons are not bonded to as many hydrogen atoms as possible. Unsaturated fatty acids are found in oils. Oils are liquid lipids that plants use to store energy. "
class of biochemical compounds that includes oils,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,B,"Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. "
general name given to biochemical polymers,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,E,"You can see from Table 2.1 that all biochemical compounds contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Most biochemical molecules are macromolecules. The prefix macro- means large, and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. The largest known biochemical molecule contains more than 34,000 monomers! "
class of biochemical compounds that includes DNA,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,D,"Nucleic acids are one of four classes of biochemical compounds. (The other three classes are carbohydrates, proteins, and lipids.) Nucleic acids include RNA (ribonucleic acid) as well as DNA (deoxyribonucleic acid). Both types of nucleic acids contain the elements carbon, hydrogen, oxygen, nitrogen, and phosphorus. Q: Which of the elements in DNA is not identified with any other class of biochemical compounds? A: All biochemical compounds contain carbon, hydrogen, and oxygen; and proteins as well as nucleic acids contain nitrogen. Phosphorus is the only element that is identified with nucleic acids. "
building blocks of proteins,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,G,"Proteins are molecules that have many different functions in living things. All proteins are made of monomers called amino acids ( Figure 1.2) that connect together like beads on a necklace ( Figure 1.3). There are only 20 common amino acids needed to build proteins. These amino acids form in thousands of different combinations, making about 100,000 or more unique proteins in humans. Proteins can differ in both the number and order of amino acids. It is the number and order of amino acids that determines the shape of the protein, and it is the shape (structure) of the protein that determines the unique function of the protein. Small proteins have just a few hundred amino acids. The largest proteins have more than 25,000 amino acids. This model shows the general structure of all amino acids. Only the side chain, R, varies from one amino acid to another. KEY: H = hydrogen, N = nitrogen, C = carbon, O = oxygen, R = variable side chain. Many important molecules in your body are proteins. Examples include enzymes, antibodies, and muscle fiber. Enzymes are a type of protein that speed up chemical reactions. They are known as ""biological catalysts."" For example, your stomach would not be able to break down food if it did not have special enzymes to speed up the rate of digestion. Antibodies that protect you against disease are proteins. Muscle fiber is mostly protein ( Figure 1.4). Muscle fibers are made mostly of protein. Its important for you and other animals to eat food with protein, because we cannot make certain amino acids on our own. You can get proteins from plant sources, such as beans, and from animal sources, like milk or meat. When you eat food with protein, your body breaks the proteins down into individual amino acids and uses them to build new proteins. You really are what you eat! "
class of biochemical compounds that includes cellulose,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,A,"Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element. "
class of biochemical compounds that includes enzymes,(A) carbohydrates (B) lipids (C) proteins (D) nucleic acids (E) macromolecules (F) fatty acids (G) amino acids,C,"Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element. "
Which of the following is one of the four main classes of biochemical compounds?,(A) sugars (B) starches (C) cellulose (D) carbohydrates,D,"Although there are millions of biochemical compounds, all of them can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in the Table 1.1. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins Q: In which class of biochemical compounds would you place glucose? A: Glucose is a sugar in the class carbohydrates. Like other carbohydrates, it contains only carbon, hydrogen, and oxygen. It provides energy to the cells of living things. Q: Look back at the chemical formula for titin. In which class of biochemical compounds should it be placed? A: Titin is a protein. You can tell because it contains sulfur, and proteins are the only biochemical compounds that contain this element. "
"All biochemical compounds include carbon, hydrogen, and",(A) sulfur (B) oxygen (C) nitrogen (D) phosphorus,B,"A biochemical compound is any carbon-based compound found in living things. Like hydrocarbons, all biochemi- cal compounds contain hydrogen as well as carbon. However, biochemical compounds also contain other elements, such as oxygen and nitrogen. Almost all biochemical compounds are polymers. They consist of many, smaller monomer molecules. Biochemical polymers are referred to as macromolecules. The prefix macro means ""large,"" and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. Biochemical compounds make up the cells and tissues of organisms. They are also involved in life processes, such as making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. However, they can be grouped into just four main classes: carbohydrates, proteins, lipids, and nucleic acids. The classes are summarized in Table 9.3 and described in the rest of this lesson. Class Carbohydrates Elements carbon hydrogen oxygen Examples sugars starches cellulose Proteins carbon hydrogen oxygen nitrogen sulfur carbon hydrogen oxygen carbon hydrogen oxygen nitrogen phosphorus enzymes hormones Lipids Nucleic acids Functions provide energy to cells store energy in plants makes up the cell walls of plants speed up biochemical re- actions regulate life processes fats oils store energy in animals store energy in plants DNA RNA stores genetic information in cells helps cells make proteins "
Organisms use carbohydrates mainly for,(A) energy (B) cell membranes (C) hormones (D) antibodies,A,"Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. "
The function of a given protein depends on its,(A) overall shape (B) sequence of amino acids (C) number of amino acid chains (D) all of the above,D,"Proteins are biochemical compounds that consist of one or more chains of small molecules called amino acids. Amino acids are the monomers of proteins. There are only about 20 different amino acids. The sequence of amino acids in chains and the number of chains in a protein determine the proteins shape. Shapes may be very complex. You can learn more about the shapes of proteins at this link: MEDIA Click image to the left or use the URL below. URL:  The shape of a protein determines its function. Proteins have many different functions. For example, proteins: make up muscle tissues. speed up chemical reactions in cells. regulate life processes. help defend against infections. 2.2. Chemistry of Living Things transport materials around the body in the blood. blood How hemoglobin transports oxygen in the "
Which statement about saturated fatty acids is true?,(A) They have only single bonds between carbon atoms (B) They are used by plants to store energy (C) They make up lipids known as oils (D) They are always in the liquid state,A,"Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, the carbons are saturated with hydrogen atoms. Saturated fatty acids are found in fats. Fats are solid lipids that animals use to store energy. In unsaturated fatty acids, there is at least one double bond between carbon atoms. As a result, some carbons are not bonded to as many hydrogen atoms as possible. Unsaturated fatty acids are found in oils. Oils are liquid lipids that plants use to store energy. "
Nitrogen bases found in both DNA and RNA include,(A) glycine (B) adenine (C) thymine (D) uracil,B,"As you can see in Figure 5.1, each nucleotide includes a sugar, a phosphate, and a nitrogen base. The sugar in DNA is called deoxyribose. There are four different nitrogen bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). Chemical bonds between the bases hold the two strands of DNA together. Adenine always bonds with thymine, and cytosine always bonds with guanine. These pairs of bases are called complementary base pairs. "
Which of the following is a function of RNA?,(A) fighting infections (B) reading the genetic code (C) carrying substances in the blood (D) all of the above,B,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
Reactants in cellular respiration include,(A) oxygen (B) water (C) carbon dioxide (D) two of the above,A,What goes into the cell? Oxygen and glucose are both reactants of cellular respiration. Oxygen enters the body when an organism breathes. Glucose enters the body when an organism eats. 
All organisms make food by photosynthesis.,(A) true (B) false,B,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
The synthesis of glucose requires carbon dioxide.,(A) true (B) false,A,"What is the source of glucose for living things? It is made by plants and certain other organisms. The process in which glucose is made using energy in light is photosynthesis. This process requires carbon dioxide and water. It produces oxygen in addition to glucose. Photosynthesis consists of many chemical reactions. Overall, the reactions of photosynthesis can be summed up by this chemical equation: 6CO2 + 6H2 O + light energy ! C6 H12 O6 + 6O2 In words, this means that six molecules of carbon dioxide (CO2 ) combine with six molecules of water (H2 O) in the presence of light energy. This produces one molecule of glucose (C6 H12 O6 ) and six molecules of oxygen (O2 ). Use this interactive animation to learn more about photosynthesis: Click on this link for a song about photosynthesis to reinforce the basic ideas:  MEDIA Click image to the left or use the URL below. URL: "
The human enzyme named pepsin catalyzes the digestion of,(A) nucleic acids (B) fatty acids (C) proteins (D) sugars,C,More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. Two examples are amylase and pepsin. Both are described in the Figure 1.2. 
Insect-catching plants such as pitcher plants obtain glucose from insects.,(A) true (B) false,B,"Carnivorous plants are plants that get some or most of their nutrients (but not energy or carbon compounds) from other organisms. They trap and digest insects or other small animals or protozoa. However, they still need sunlight in order to make food by photosynthesis. Carnivorous plants have adapted to grow in places where the soil is thin or poor in nutrients. They are found in places such as bogs and rock outcroppings. Venus fly traps, like those in Figure in action:  . MEDIA Click image to the left or use the URL below. URL: "
The compound that cells break down to release energy is,(A) chlorophyll (B) carbon dioxide (C) water (D) glucose,D,"The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. The rest of the energy is used to form many small molecules of a compound called adenosine triphosphate, or ATP. ATP molecules contain just the right amount of stored chemical energy to power biochemical reactions inside cells. Click image to the left or use the URL below. URL: "
Energy for photosynthesis comes from,(A) water (B) soil (C) light (D) chemicals,C,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
Chemical reactions provide living cells with energy.,(A) true (B) false,A,"Organic molecules must also carry out the chemical work of cells; that is, their metabolism. Chemical reactions in a living organism allow that organism to live in its environment, grow, and reproduce. Metabolism gets energy from other sources and creates structures needed in cells. The chemical reactions occur in a sequence of steps known as metabolic pathways. The metabolic pathways are very similar between unicellular bacteria that have been around for billions of years and the most complex life forms on Earth today. This means that they evolved very early in Earths history. "
"Photosynthesis is an exothermic, or energy-releasing, process.",(A) true (B) false,B,"One of the most important series of endothermic reactions is photosynthesis. In photosynthesis, plants make the simple sugar glucose (C6 H12 O6 ) from carbon dioxide (CO2 ) and water (H2 O). They also release oxygen (O2 ) in the process. The reactions of photosynthesis are summed up by this chemical equation: 6 CO2 + 6 H2 O  C6 H12 O6 + 6 O2 The energy for photosynthesis comes from light. Without light energy, photosynthesis cannot occur. As you can see in the Figure 1.2, plants can get the energy they need for photosynthesis from either sunlight or artificial light. "
Which equation correctly represents photosynthesis?,(A) C6 H12 O6 + 6O2 + energy  6CO2 + 6H2 O (B) 6CO2 + 6O2 + energy  C6 H12 O6 + 6H2 O (C) C6 H12 O6 + 6CO2 + energy  6O2 + 6H2 O (D) 6CO2 + 6H2 O + energy  C6 H12 O6 + 6O2,D,"The overall chemical reaction for photosynthesis is 6 molecules of carbon dioxide (CO2 ) and 6 molecules of water (H2 O), with the addition of solar energy. This produces 1 molecule of glucose (C6 H12 O6 ) and 6 molecules of oxygen Stomata are special pores that allow gasses to enter and exit the leaf. (O2 ). Using chemical symbols, the equation is represented as follows: 6CO2 + 6H2 O  C6 H12 O6 + 6O2 . Though this equation may not seem that complicated, photosynthesis is a series of chemical reactions divided into two stages, the light reactions and the Calvin cycle ( Figure 1.3). "
The overall chemical reaction for photosynthesis is represented by the equation: C6 H12 O6 + 6O2  6CO2,(A) true (B) false,B,"The overall chemical reaction for photosynthesis is 6 molecules of carbon dioxide (CO2 ) and 6 molecules of water (H2 O), with the addition of solar energy. This produces 1 molecule of glucose (C6 H12 O6 ) and 6 molecules of oxygen Stomata are special pores that allow gasses to enter and exit the leaf. (O2 ). Using chemical symbols, the equation is represented as follows: 6CO2 + 6H2 O  C6 H12 O6 + 6O2 . Though this equation may not seem that complicated, photosynthesis is a series of chemical reactions divided into two stages, the light reactions and the Calvin cycle ( Figure 1.3). "
"Products of cellular respiration include many small, energy-storing molecules.",(A) true (B) false,A,"The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. The rest of the energy is used to form many small molecules of a compound called adenosine triphosphate, or ATP. ATP molecules contain just the right amount of stored chemical energy to power biochemical reactions inside cells. Click image to the left or use the URL below. URL: "
Cellular respiration takes place only in organisms that cannot make their own food.,(A) true (B) false,B,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
The process of cellular respiration requires carbon dioxide.,(A) true (B) false,B,"Cellular respiration involves many biochemical reactions. However, the overall process can be summed up in a single chemical equation: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + energy (stored in ATP) Cellular respiration uses oxygen in addition to glucose. It releases carbon dioxide and water as waste products. Cellular respiration actually ""burns"" glucose for energy. However, it doesnt produce light or intense heat like burning a candle or log. Instead, it releases the energy slowly, in many small steps. The energy is used to form dozens of molecules of ATP. "
One of the products of cellular respiration is oxygen.,(A) true (B) false,B,"What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be converted to a net total of 36 or 38 molecules of ATP. This only occurs in the presence of oxygen. "
All living things need energy just to stay alive.,(A) true (B) false,A,"All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ecosystems. "
"Cellular respiration is an endothermic, or energy-absorbing, process.",(A) true (B) false,B,"Cellular respiration is the process in which the cells of living things break down glucose with oxygen to produce carbon dioxide, water, and energy. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + Heat and Chemical Energy Cellular respiration releases some of the energy in glucose as heat. It uses the rest of the energy to form many, even smaller molecules. The smaller molecules contain just the right amount of energy to power chemical reactions inside cells. You can look at cellular respiration in more detail at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Only plants can carry out photosynthesis.,(A) true (B) false,B,"By the time the earliest plants evolved, animals were already the dominant living things in the water. Plants were also limited to the upper layer of water. Only near the top of the water column is there enough sunlight for photosynthesis. So plants never became dominant aquatic organisms. "
Cellular respiration occurs in all living cells,(A) true (B) false,A,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
One of the products of cellular respiration is oxygen.,(A) true (B) false,B,"What does the cell produce? The products of cellular respiration are carbon dioxide and water. Carbon dioxide is transported from your mitochondria out of your cell, to your red blood cells, and back to your lungs to be exhaled. ATP is generated in the process. When one molecule of glucose is broken down, it can be converted to a net total of 36 or 38 molecules of ATP. This only occurs in the presence of oxygen. "
process in which cells break down glucose and release energy,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,D,"Cellular respiration is the process in which cells break down glucose, release the stored energy, and use the energy to make ATP. For each glucose molecule that undergoes this process, up to 38 molecules of ATP are produced. Each ATP molecules forms when a phosphate is added to ADP, or adenosine diphosphate. This requires energy, which is stored in the ATP molecule. When cells need energy, a phosphate can be removed from ATP. This releases the energy and forms ADP again. "
any chemical reaction that takes place in living things,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,B,Chemical reactions that take place inside living things are called biochemical reactions (bio- means life). Its not just for energy that living things depend on biochemical reactions. Every function and structure of a living organism depends on thousands of biochemical reactions taking place in each cell. The sum of all these biochemical reactions is called metabolism. 
protein that speeds up biochemical reactions,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,G,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
byproduct of photosynthesis,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,C,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
compound that cells use for energy,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,E,"Chemical energy that organisms need comes from food. The nearly universal food for life is the sugar glucose. Glucose is a simple carbohydrate with the chemical formula C6 H12 O6 . The glucose molecule stores chemical energy in a concentrated, stable form. In your body, glucose is the form of energy that is carried in your blood and taken up by each of your trillions of cells. "
pigment that captures light energy,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,F,"Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is chlorophyll, which is found in plants. This dark green pigment absorbs all but green wavelengths of visible light. It is responsible for capturing the light energy needed for photosynthesis. Pigments are also found in paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary pigment colors are the same as the secondary colors of light: cyan, magenta, and yellow. The printer ink cartridges in Figure 22.8 come in just these three colors. They are the only colors needed for full-color printing. "
process in which certain organisms make glucose,(A) photosynthesis (B) biochemical reaction (C) oxygen (D) cellular respiration (E) glucose (F) chlorophyll (G) enzyme,A,"Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs (""self feeders""). All other living things obtain glucose by eating autotrophs (or organisms that eat autotrophs). These living things are called heterotrophs (""other feeders""). "
All living things need,(A) carbon dioxide (B) sunlight (C) energy (D) two of the above,C,"All living things need energy. They need it to power the processes of life. For example, it takes energy to grow. It also takes energy to produce offspring. In fact, it takes energy just to stay alive. Remember that energy cant be created or destroyed. It can only change form. Energy changes form as it moves through ecosystems. "
Reactants in photosynthesis include,(A) chlorophyll (B) oxygen (C) glucose (D) water,D,"What goes into the plant cell to start photosynthesis? The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the suns energy are necessary for photosynthesis to occur. These three components must meet in the chloroplast of the leaf cell for photosynthesis to occur. How do these three components get to the cells in the leaf? Chlorophyll is the green pigment in leaves that captures energy from the sun. Chlorophyll molecules are located in the thylakoid membranes inside chloroplasts. The veins in a plant carry water from the roots to the leaves. Carbon dioxide enters the leaf from the air through special openings called stomata ( Figure 1.2). "
Types of organisms that make their own glucose include,(A) algae (B) plants (C) cyanobacteria (D) all of the above,D,"Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs (""self feeders""). All other living things obtain glucose by eating autotrophs (or organisms that eat autotrophs). These living things are called heterotrophs (""other feeders""). "
All organisms that undergo photosynthesis contain,(A) pepsin (B) amylase (C) chlorophyll (D) two of the above,C,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
Cellular respiration releases some energy in the form of,(A) heat (B) light (C) motion (D) electricity,A,"Cellular respiration is the process in which the cells of living things break down glucose with oxygen to produce carbon dioxide, water, and energy. The overall chemical equation for cellular respiration is: C6 H12 O6 + 6O2 ! 6CO2 + 6H2 O + Heat and Chemical Energy Cellular respiration releases some of the energy in glucose as heat. It uses the rest of the energy to form many, even smaller molecules. The smaller molecules contain just the right amount of energy to power chemical reactions inside cells. You can look at cellular respiration in more detail at this URL:  MEDIA Click image to the left or use the URL below. URL: "
Amylase catalyzes the breakdown of,(A) lipids (B) proteins (C) nucleic acids (D) complex carbohydrates,D,"Chemical reactions constantly occur inside living things. Many of these reactions require catalysts so they will occur quickly enough to support life. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take many years without it! More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. An example is amylase, which is found in the mouth and small intestine. Amylase catalyzes the breakdown of starch to sugar. You can see how it affects the rate of starch digestion in the Figure 1.2. A: The starches in the cracker start to break down to sugars with the help of the enzyme amylase. Try this yourself and see if you can taste the reaction. "
acceleration always refers to a(n),(A) increase in speed (B) change in speed (C) change in direction (D) change in velocity,D,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
acceleration is a vector.,(A) true (B) false,A,"Acceleration is a measure of the change in velocity of a moving object. It measures the rate at which velocity changes. Velocity, in turn, is a measure of the speed and direction of motion, so a change in velocity may reflect a change in speed, a change in direction, or both. Both velocity and acceleration are vectors. A vector is any measurement that has both size and direction. People commonly think of acceleration as in increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative and called deceleration. A change in direction without a change in speed is acceleration as well. Q: Can you think of an example of acceleration that doesnt involve a change in speed? A: Driving at a constant speed around a bend in a road is one example. Use your imagination to think of others. "
a change in direction without a change in speed is called velocity.,(A) true (B) false,B,"You can see several examples of acceleration in the pictures from the Figure 1.1. In each example, velocity is changing but in different ways. For example, direction may be changing but not speed, or vice versa. Figure out what is moving and how its moving in each of the photos. Q: Describe how velocity is changing in each of the motions you identified from the Figure 1.1. A: You should describe how both direction and speed are changing. For example, the boy on the carousel is moving up and down and around in a circle, so his direction is constantly changing, but his speed changes only at the beginning and end of the ride. The skydiver is falling straight down toward the ground so her direction isnt changing, but her speed keeps increasing as she falls until she opens her parachute. "
acceleration can never be negative.,(A) true (B) false,B,"Acceleration is a measure of the change in velocity of a moving object. It shows how quickly velocity changes. Acceleration may reflect a change in speed, a change in direction, or both. Because acceleration includes both a size (speed) and direction, it is a vector. People commonly think of acceleration as an increase in speed, but a decrease in speed is also acceleration. In this case, acceleration is negative. Negative acceleration may be called deceleration. A change in direction without a change in speed is acceleration as well. You can see several examples of acceleration in Figure 12.11. If you are accelerating, you may be able to feel the change in velocity. This is true whether you change your speed or your direction. Think about what it feels like to ride in a car. As the car speeds up, you feel as though you are being pressed against the seat. The opposite occurs when the car slows down, especially if the change in speed is "
a heavier object always falls to the ground more quickly than a lighter object.,(A) true (B) false,B,"What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at the same time. The reason? The more massive bowling ball is also harder to move because of its greater mass, so it ends up moving at the same acceleration as the soccer ball. This is true of all falling objects. They all accelerate at the same rate due to gravity, unless air resistance affects one object more than another. For example, a falling leaf is slowed down by air resistance more than a falling acorn because of the leafs greater surface area. Q: If a leaf and an acorn were to fall to the ground in the absence of air (that is, in a vacuum), how would this affect their acceleration due to gravity? A: They would both accelerate at the same rate and reach the ground at the same time. "
what is the velocity of an object that has been falling freely in a vacuum for 4 seconds?,(A) 98 m/s (B) 101 m/s (C) 196 m/s (D) 392 m/s,D,"Gravity is a force that pulls objects down toward the ground. When objects fall to the ground, gravity causes them to accelerate. Acceleration is a change in velocity, and velocity, in turn, is a measure of the speed and direction of motion. Gravity causes an object to fall toward the ground at a faster and faster velocity the longer the object falls. In fact, its velocity increases by 9.8 m/s2, so by 1 second after an object starts falling, its velocity is 9.8 m/s. By 2 seconds after it starts falling, its velocity is 19.6 m/s (9.8 m/s + 9.8 m/s), and so on. The acceleration of a falling object due to gravity is illustrated in the Figure 1.1. Q: In this diagram, the boy drops the object at time t= 0 s. By t = 1 s, the object is falling at a velocity of 9.8 m/s. What is its velocity by t = 5 s? What will its velocity be at t = 6 s if it keeps falling? A: Its velocity at t = 5 s is 49.0 m/s, and at t = 6 s, it will be 58.8 m/s (49.0 m/s + 9.8 m/s). "
objects fall toward earth at a constant rate of speed.,(A) true (B) false,B,"When gravity pulls objects toward the ground, it causes them to accelerate. Acceleration due to gravity equals 9.8 m/s2 . In other words, the velocity at which an object falls toward Earth increases each second by 9.8 m/s. Therefore, after 1 second, an object is falling at a velocity of 9.8 m/s. After 2 seconds, it is falling at a velocity of 19.6 m/s (9.8 m/s  2), and so on. This is illustrated in Figure 13.20. You can compare the acceleration due to gravity on Earth, the moon, and Mars with the interactive animation called ""Freefall"" at this URL: http://jersey.uoregon.edu/vlab/ . You might think that an object with greater mass would accelerate faster than an object with less mass. After all, its greater mass means that it is pulled by a stronger force of gravity. However, a more massive object accelerates at the same rate as a less massive object. The reason? The more massive object is harder to move because of its greater mass. As a result, it ends up moving at the same acceleration as the less massive object. Consider a bowling ball and a basketball. The bowling ball has greater mass than the basketball. However, if you were to drop both balls at the same time from the same distance above the ground, they would reach the ground together. This is true of all falling objects, unless air resistance affects one object more than another. For example, a falling leaf is slowed down by air resistance more than a falling acorn because of the leafs greater surface area. However, if the leaf and acorn were to fall in the absence of air (that is, in a vacuum), they would reach the ground at the same time. "
an object will experience more air resistance when it falls if it has greater,(A) mass (B) weight (C) gravity (D) surface area,D,"What if you were to drop a bowling ball and a soccer ball at the same time from the same distance above the ground? The bowling ball has greater mass than the basketball, so the pull of gravity on it is greater. Would it fall to the ground faster? No, the bowling ball and basketball would reach the ground at the same time. The reason? The more massive bowling ball is also harder to move because of its greater mass, so it ends up moving at the same acceleration as the soccer ball. This is true of all falling objects. They all accelerate at the same rate due to gravity, unless air resistance affects one object more than another. For example, a falling leaf is slowed down by air resistance more than a falling acorn because of the leafs greater surface area. Q: If a leaf and an acorn were to fall to the ground in the absence of air (that is, in a vacuum), how would this affect their acceleration due to gravity? A: They would both accelerate at the same rate and reach the ground at the same time. "
objects with different masses have the same gravitational force acting on them.,(A) true (B) false,B,"Gravity has traditionally been defined as a force of attraction between two masses. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. The effect of gravity is that objects exert a pull on other objects. Unlike friction, which acts only between objects that are touching, gravity also acts between objects that are not touching. In fact, gravity can act over very long distances. "
"if a measurement is precise, it must also be accurate.",(A) true (B) false,B,"Measurements should be both accurate and precise. Accuracy is how close a measurement is to the true value. For example, 66 mL is a fairly accurate measure- ment of the liquid in Figure 2.6. Precision is how exact a measurement is. A measurement of 65.5 mL is more precise than a measurement of 66 mL. But in Figure 2.6, it is not as accurate. You can think of accuracy and precision in terms of a game like darts. If you are aiming for the bulls-eye and get all of the darts close to it, you are being both accurate and precise. If you get the darts all close to each other somewhere else on the board, you are precise, but not accurate. And finally, if you get the darts spread out all over the board, you are neither accurate nor precise. "
only accurate measurements are precise.,(A) true (B) false,B,"The accuracy of a measurement is how close the measurement is to the true value. If you were to hit four different golf balls toward an over-sized hole, all of them might land in the hole. These shots would all be accurate because they all landed in the hole. This is illustrated in the sketch below. "
which set of measurements best represents precision if the true value is 6.80 kg?,(A) 680 kg (B) 670 kg (C) and 690 kg (D) b 675 kg (E) 680 kg (F) and 685 kg (G) c 580 kg (H) 680 kg (I) and 780 kg (J) d 610 kg (K) 599 kg (L) and 611 kg,D,"Measurements should be both accurate and precise. Accuracy is how close a measurement is to the true value. For example, 66 mL is a fairly accurate measure- ment of the liquid in Figure 2.6. Precision is how exact a measurement is. A measurement of 65.5 mL is more precise than a measurement of 66 mL. But in Figure 2.6, it is not as accurate. You can think of accuracy and precision in terms of a game like darts. If you are aiming for the bulls-eye and get all of the darts close to it, you are being both accurate and precise. If you get the darts all close to each other somewhere else on the board, you are precise, but not accurate. And finally, if you get the darts spread out all over the board, you are neither accurate nor precise. "
which set of measurements best represents accuracy if the true value is 6.80 kg?,(A) 680 kg (B) 670 kg (C) and 690 kg (D) b 675 kg (E) 680 kg (F) and 685 kg (G) c 580 kg (H) 680 kg (I) and 780 kg (J) d 610 kg (K) 599 kg (L) and 611 kg,B,"The accuracy of a measurement is how close the measurement is to the true value. If you were to hit four different golf balls toward an over-sized hole, all of them might land in the hole. These shots would all be accurate because they all landed in the hole. This is illustrated in the sketch below. "
pure water is an example of a neutral substance.,(A) true (B) false,A,"Water (H2 O) is an example of a chemical compound. Water molecules always consist of two atoms of hydrogen and one atom of oxygen. Like water, all other chemical compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. "
"when an acid dissolves in water, it produces",(A) positive hydrogen ions (B) negative nonmetal ions (C) negative metal ions (D) two of the above,D,"An acid is a compound that produces positive hydrogen ions (H+ ) and negative nonmetal ions when it dissolves in water. (Ions are atoms that have become charged by losing or gaining electrons.) Hydrochloric acid (HCl) is an example of an acid. When it dissolves in water, it produces positive hydrogen ions and negative chloride ions (Cl ). This can be represented by the chemical equation: H O 2 HCl H+ + Cl A base is a compound that produces negative hydroxide ions (OH ) and positive metal ions when it dissolves in water. For example, when the base sodium hydroxide (NaOH) dissolves in water, it produces negative hydroxide ions and positive sodium ions (Na+ ). This can be represented by the chemical equation: H O 2 NaOH OH + Na+ Q: If you were to combine acid and base solutions, what products do you think would be produced? A: Combining acid and base solutions produces water and a neutral ionic compound. "
"when a base dissolves in water, it produces",(A) positive hydroxide ions (B) positive metal ions (C) negative nonmetal ions (D) two of the above,B,"A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ "
the reaction of hydrochloric acid and calcium carbonate produces,(A) water (B) calcium chloride (C) carbon dioxide (D) all of the above,D,"When an acid and a base react, the reaction is called a neutralization reaction. Thats because the reaction produces neutral products. Water is always one product, and a salt is also produced. A salt is a neutral ionic compound. Lets see how a neutralization reaction produces both water and a salt, using as an example the reaction between solutions of hydrochloric acid and sodium hydroxide. The overall equation for this reaction is: NaOH + HCl  H2 O and NaCl Now lets break this reaction down into two parts to see how each product forms. Positive hydrogen ions from HCl and negative hydroxide ions from NaOH combine to form water. This part of the reaction can be represented by the equation: H+ + OH  H2 O Positive sodium ions from NaOH and negative chloride ions from HCL combine to form the salt sodium chloride (NaCl), commonly called table salt. This part of the reaction can be represented by the equation: Na+ + Cl  NaCl Another example of a neutralization reaction can be seen in the Figure 1.1. Q: What products are produced when antacid tablets react with hydrochloric acid in the stomach? A: The products are water and the salt calcium chloride (CaCl2 ). Carbon dioxide (CO2 ) is also produced. The reaction is represented by the chemical equation: CaCO3 + 2HCl  H2 O + CaCl2 + CO2 "
only endothermic reactions require activation energy.,(A) true (B) false,B,"Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energy. But do exothermic reactions also need activation energy? A: All chemical reactions need energy to get started, even exothermic reactions. Look at the Figure 1.1. They compare energy changes that occur during endothermic and exothermic reactions. From the graphs, you can see that both types of reactions need the same amount of activation energy in order to get started. Only after it starts does the exothermic reaction produce more energy than it uses. "
the activation energy needed to start combustion in a car engine comes from,(A) the gasoline (B) a spark plug (C) a piston (D) the key,B,"Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas wont occur without the spark of energy to begin the reaction. Q: Why is activation energy needed? Why wont a reaction occur without it? A: A reaction wont occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. "
a chemical reaction will not occur unless reactants are moving.,(A) true (B) false,A,"Chemical reactions also need energy to be activated. They require a certain amount of energy just to get started. This energy is called activation energy. For example, activation energy is needed to start a car engine. Turning the key causes a spark that activates the burning of gasoline in the engine. The combustion of gas wont occur without the spark of energy to begin the reaction. Q: Why is activation energy needed? Why wont a reaction occur without it? A: A reaction wont occur unless atoms or molecules of reactants come together. This happens only if the particles are moving, and movement takes energy. Often, reactants have to overcome forces that push them apart. This takes energy as well. Still more energy is needed to start breaking bonds in reactants. "
all chemical reactions need a constant input of energy to continue.,(A) true (B) false,B,"Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energy. But do exothermic reactions also need activation energy? A: All chemical reactions need energy to get started, even exothermic reactions. Look at the Figure 1.1. They compare energy changes that occur during endothermic and exothermic reactions. From the graphs, you can see that both types of reactions need the same amount of activation energy in order to get started. Only after it starts does the exothermic reaction produce more energy than it uses. "
exothermic reactions always need less activation energy than endothermic reactions.,(A) true (B) false,B,"Some chemical reactions need a constant input of energy to take place. They are called endothermic reactions. Other chemical reactions release energy when they occur, so they can keep going without any added energy. They are called exothermic reactions. Q: It makes sense that endothermic reactions need activation energy. But do exothermic reactions also need activation energy? A: All chemical reactions need energy to get started, even exothermic reactions. Look at the Figure 1.1. They compare energy changes that occur during endothermic and exothermic reactions. From the graphs, you can see that both types of reactions need the same amount of activation energy in order to get started. Only after it starts does the exothermic reaction produce more energy than it uses. "
all of the following are alkaline earth metals except,(A) barium (B) sodium (C) calcium (D) magnesium,B,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
properties of alkaline earth metals include,(A) gray or silver color (B) low density (C) softness (D) all of the above,D,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
all alkaline earth metals have three valence electrons.,(A) true (B) false,B,"All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metals in group 1. For example, alkaline Earth metals will react with cold water, but not explosively as alkali metals do. Because of their reactivity, alkaline Earth metals never exist as pure substances in nature. Instead, they are always found combined with other elements. The reactivity of alkaline Earth metals increases from the top to the bottom of the group. Thats because the atoms get bigger from the top to the bottom, so the valence electrons are farther from the nucleus. When valence electrons are farther from the nucleus, they are attracted less strongly by the nucleus and more easily removed from the atom. This makes the atom more reactive. Q: Alkali metals have just one valence electron. Why are alkaline Earth metals less reactive than alkali metals? A: It takes more energy to remove two valence electrons from an atom than one valence electron. This makes alkaline Earth metals with their two valence electrons less reactive than alkali metals with their one valence electron. "
alkaline earth metals are the most reactive metals.,(A) true (B) false,B,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
alkaline earth metals never exist as pure substances in nature.,(A) true (B) false,A,"The alkaline Earth metals include all the elements in group 2 (see Figure 6.10). These metals have just two valence electrons, so they are very reactive, although not quite as reactive as the alkali metals. In nature, they are always found combined with other elements. Alkaline Earth metals are silvery grey in color. They are harder and denser than the alkali metals. All are solids at room temperature. "
diets that are too low in calcium may lead to,(A) rickets (B) osteoporosis (C) bone fractures (D) all of the above,D,"Osteoporosis is a disease in which the bones become porous and weak because they do not contain enough calcium. The graph in Figure 16.14 shows how the mass of calcium in bone peaks around age 30 and declines after that, especially in women. Maximizing the calcium in your bones while youre young will reduce your risk of developing osteoporosis later in of life. "
alloys consist only of metallic elements.,(A) true (B) false,B,"An alloy is a mixture of a metal with one or more other elements. The other elements may be metals, nonmetals, or both. An alloy is formed by melting a metal and dissolving the other elements in it. The molten solution is then allowed to cool and harden. Alloys generally have more useful properties than pure metals. Several examples of alloys are described and pictured below. If you have braces on your teeth, you might even have this alloy in your mouth! Click image to the left or use the URL below. URL: "
most metal objects are made of alloys rather than pure metals.,(A) true (B) false,A,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
which of the following is not an alloy?,(A) chromium (B) bronze (C) brass (D) steel,A,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
the alloy called stainless steel consists of,(A) iron (B) carbon (C) nickel (D) all of the above,D,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
the first alloy ever made was,(A) sterling silver (B) steel (C) brass (D) bronze,D,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
brass is an alloy that is used for doorknobs and plumbing fixtures.,(A) true (B) false,A,"Most metal objects are made of alloys rather than pure metals. Objects made of four different alloys are shown in the Figure 1.1. Brass saxophone: Brass is an alloy of copper and zinc. It is softer than bronze and easier to shape. Its also very shiny. Notice the curved pieces in this shiny brass saxophone. Brass is used for shap- ing many other curved objects, such as doorknobs and plumbing fixtures. Stain- less steel sink: Stainless steel is a type of steel that contains nickel and chromium in addition to carbon and iron. It is shiny, strong, and resistant to rusting. This makes it useful for sinks, eating utensils, and other objects that are exposed to wa- ter. ""Gold"" bracelet: Pure gold is relatively soft, so it is rarely used for jewelry. Most ""gold"" jewelry is actually made of an alloy of gold, copper and silver. Bronze statue: Bronze was the first alloy ever made. The earliest bronze dates back many thou- sands of years. Bronze is a mixture of copper and tin. Both copper and tin are relatively soft metals, but mixed together in bronze they are much harder. Bronze has been used for statues, coins, and other objects. Q: Sterling silver is an alloy that is used to make fine jewelry. What elements do you think sterling silver contains? What properties might sterling silver have that make it more useful than pure silver? A: Most sterling silver is about 93 percent silver and about 7 percent copper. Sterling silver is harder and stronger than pure silver, while retaining the malleability and luster of pure silver. "
an alpha particle is a,(A) packet of energy (B) single electron (C) helium nucleus (D) none of the above,C,"Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure 1.1 shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus. Losing the protons and neutrons makes the nucleus more stable. "
what does the following nuclear symbol represent?,(A) alpha particle (B) helium atom (C) helium ion (D) none of the above,A,"Radioactive nuclei and particles are represented by nuclear symbols.. For example, a beta-minus particle (electron) is represented by the symbol 01 e. The subscript -1 represents the particles charge, and the superscript 0 shows that the particle has virtually no mass (no protons or neutrons). Another example is the radioactive nucleus of thorium-234. It is represented by the symbol 234 90 Th, where the subscript 90 stands for the number of protons and the superscript 234 for the number of protons plus neutrons. Nuclear symbols are used to write nuclear equations for radioactive decay. Lets consider the example of the beta- minus decay of thorium-234 to protactinium-234. This reaction is represented by the equation: 234 Th 90 0 234 91 Pa + 1 e + energy The equation shows that thorium-234 becomes protactinium-234 and loses a beta particle and energy. The protactinium- 234 produced in the reaction is also radioactive, so it will decay as well. A nuclear equation is balanced if the total numbers of protons and neutrons are the same on both sides of the arrow. If you compare the subscripts and superscripts on both sides of the equation above, youll see that they are the same. Q: What happens to the electron produced in the reaction above? A: Along with another electron, it can combine with an alpha particle to form a helium atom. An alpha particle, which is emitted during alpha decay, consists of two protons and two neutrons. Q: Try to balance the following nuclear equation for beta-minus decay by filling in the missing subscript and superscript. 131 I 53 ?? Xe + 01 e + energy A: The subscript of Xe is 54, and the superscript is 131. "
"in the nuclear symbol 6 c, the superscript represents the",(A) atomic number (B) mass number (C) valence number (D) group number,B,"Radioactive nuclei and particles are represented by nuclear symbols that indicate their numbers of protons and neutrons. For example, an alpha particle (helium nucleus) is represented by the symbol 42 He, where He is the chemical symbol for helium, the subscript 2 is the number of protons, and the superscript 4 is the mass number (2 protons + 2 neutrons). Nuclear symbols are used to write nuclear equations for radioactive decay. Lets consider an example. Uranium-238 undergoes alpha decay to become thorium-234. (The numbers following the chemical names refer to the number of protons plus neutrons.) In this reaction, uranium-238 loses two protons and two neutrons to become the element thorium-234. The reaction can be represented by this nuclear equation: 238 U 92 4 234 90 Th + 2 He + Energy If you count the number of protons (subscripts) as well as the number of protons plus neutrons (superscripts), youll see that the total numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is also unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can join with two free electrons to form the element helium. This is how most of Earths helium formed. Q: Fill in the missing subscript and superscript to balance the following nuclear equation for alpha decay of Polonium-210. 210 Po 84 ?? Pb + 42 He + Energy A: The subscript of Pb is 82, and the superscript is 206. This means that the new element produced in the reaction has 82 protons. You can find the element with this number of protons in the periodic table. It is the element lead (Pb). The new element also has 124 neutrons (206 - 82 protons = 124 neutrons). "
"in the following nuclear equation for alpha decay, what is the missing subscript that will balance the equation? th + 42 he + energy 238 234",(A) 94 (B) 92 (C) 90 (D) 88,C,"Alpha decay occurs when an unstable nucleus emits an alpha particle and energy. The diagram in Figure 11.6 represents alpha decay. An alpha particle contains two protons and two neutrons, giving it a charge of +2. A helium nucleus has two protons and two neutrons, so an alpha particle is represented in nuclear equations by the symbol 4 He. 2 The superscript 4 is the mass number (2 protons + 2 neutrons). The subscript 2 is the charge of the particle as well as the number of protons. An example of alpha decay is the decay of uranium-238 to thorium-234. In this reaction, uranium loses two protons and two neutrons to become the element thorium. The reaction can be represented by this equation: 238 92 U 4 !234 90 Th +2 He + Energy If you count the number of protons and neutrons on each side of this equation, youll see that the numbers are the same on both sides of the arrow. This means that the equation is balanced. The thorium-234 produced in this reaction is unstable, so it will undergo radioactive decay as well. The alpha particle (42 He) produced in the reaction can pick up two electrons to form the element helium. This is how most of Earths helium formed. Problem Solving ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 208 84 Po !? Pb +2 He + Energy Solution: The subscript is 82, and the superscript is 204. You Try It! ? 4 Problem: Fill in the missing subscript and superscript to balance this nuclear equation: 222 ? Ra !86 Rn+2 He+Energy "
an alpha particle consists of one proton and one neutron.,(A) true (B) false,B,"Alpha decay occurs when a nucleus is unstable because it has too many protons. The Figure 1.1 shows what happens during alpha decay. The nucleus emits an alpha particle and energy. An alpha particle consists of two protons and two neutrons, which is actually a helium nucleus. Losing the protons and neutrons makes the nucleus more stable. "
alpha decay is the least dangerous type of radioactive decay.,(A) true (B) false,A,"All types of radioactive decay pose risks to living things, but alpha decay is the least dangerous. Thats because alpha particles are relatively heavy, so they can travel only a few centimeters through the air. They also are not very penetrating. For example, they cant pass through a sheet of paper or thin layer of clothing. They may burn the skin, but they cant penetrate to the tissues underneath the skin. However, if alpha particles are emitted inside the body, they can do more damage. One way this can happen is by inhaling cigarette smoke. People who smoke actually inhale the radioactive element polonium-210. It undergoes alpha decay in the lungs. Over time, exposure to alpha particles may cause lung cancer. "
archimedes was a greek mathematician who lived more than 2000 years ago.,(A) true (B) false,A,"Some of the earliest scientific research on fluids was conducted by a French mathematician and physicist named Blaise Pascal (16231662). Pascal was a brilliant thinker. While still a teen, he derived an important theorem in mathematics and also invented a mechanical calculator. One of Pascals contributions to our understanding of fluids is known as Pascals law. "
archimedes determined that the volume of water displaced by an object placed in the water is equal to the objects,(A) weight (B) volume (C) mass (D) density,B,"Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. Q: If you jump into swimming pool, how much water does your body displace? A: The water displaced by your body is equal to your bodys volume. Depending on your size, this volume might be about 0.07 m3 . "
a bigger object displaces less water than a smaller object.,(A) true (B) false,B,"Did you ever notice when you get into a bathtub of water that the level of the water rises? More than 2000 years ago, a Greek mathematician named Archimedes noticed the same thing. He observed that both a body and the water in a tub cant occupy the same space at the same time. As a result, some of the water is displaced, or moved out of the way. How much water is displaced? Archimedes determined that the volume of displaced water equals the volume of the submerged object. So more water is displaced by a bigger body than a smaller one. Q: If you jump into swimming pool, how much water does your body displace? A: The water displaced by your body is equal to your bodys volume. Depending on your size, this volume might be about 0.07 m3 . "
"according to archimedes law, the buoyant force acting on an object equals the",(A) weight of the object (B) weight of the displaced fluid (C) volume of the object (D) volume of the displaced fluid,B,Objects such as ships may float in a fluid like water because of buoyant force. This is an upward force that a fluid exerts on any object that is placed in it. Archimedes discovered that the buoyant force acting on an object equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Archimedes principle). 
archimedes law explains why some very heavy objects can float on water.,(A) true (B) false,A,"Archimedes law explains why some objects float in fluids even though they are very heavy. It all depends on how much fluid they displace. The cruise ship pictured in the opening image is extremely heavy, yet it stays afloat. If a steel ball with the same weight as the ship were placed in water, it would sink to the bottom. This is modeled in the Figure 1.1. The reason the ball sinks is that its shape is very compact, so it displaces relatively little water. The volume of water displaced by the steel ball weighs less than the ball itself, so the buoyant force is not as great as the force of gravity pulling down on the ball. Thus, the ball sinks. Now look at the ships hull in the Figure 1.1. Its shape causes the ship to displace much more water than the ball. In fact, the weight of the displaced water is greater than the weight of the ship. As a result, the buoyant force is greater than the force of gravity acting on the ship, so the ship floats. Q: Why might you be more likely to float in water if you stretch out your body rather than curl up into a ball? A: You would displace more water by stretching out your body, so there would be more buoyant force acting on it. Therefore, you would be more likely to float in this position. "
how does an incandescent light bulb produce visible light?,(A) The bulb’s filament gets so hot that it glows (B) Gas inside the bulb gives off visible light (C) Electricity excites neon electrons in the bulb (D) two of the above,A,"An incandescent light bulb like the one pictured in the Figure 1.1 produces visible light by incandescence. Incan- descence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light. "
"in a fluorescent light bulb, mercury gas gives off visible light.",(A) true (B) false,B,A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure 1.2 contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. 
gases used in halogen lights include,(A) neon (B) argon (C) mercury (D) two of the above,D,"The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine is red, and iodine and astatine are nearly black. Like other nonmetals, halogens cannot conduct electricity or heat. Compared with most other elements, halogens have relatively low melting and boiling points. "
a vapor light produces light by fluorescence.,(A) true (B) false,B,A fluorescent light bulb produces visible light by fluorescence. Fluorescence occurs when a substance absorbs shorter-wavelength ultraviolet light and then gives off the energy as visible light. The compact fluorescent light bulb (CFL) in the Figure 1.2 contains mercury gas that gives off ultraviolet light when electricity passes through it. The inside of the bulb is coated with a substance called phosphor. Phosphor absorbs the ultraviolet light and then gives off most of the energy as visible light. 
forces that hold together particles within the atom include,(A) gravity (B) electromagnetic force (C) weak nuclear force (D) two of the above,D,"When it comes to atomic particles, opposites attract. Negative electrons are attracted to positive protons. This force of attraction keeps the electrons moving about the nucleus. An analogy is the way planets orbit the sun. What about particles with the same charge, such as protons in the nucleus? They push apart, or repel, each other. So why doesnt the nucleus fly apart? The reason is a force of attraction between protons and neutrons called the strong force. The name of the strong force suits it. It is stronger than the electric force pushing protons apart. However, the strong force affects only nearby particles (see Figure 5.3). It is not effective if the nucleus gets too big. This puts an upper limit on the number of protons an atom can have and remain stable. You can learn more about atomic forces in the colorful tutorial at this URL:  . "
the strong nuclear force is a force of attraction between quarks.,(A) true (B) false,A,"The strong nuclear force is a force of attraction between fundamental particles called quarks, which have a type of charge called color charge. The strong nuclear force is transferred between quarks by fundamental force-carrying particles called gluons. Both protons and neutrons consist of quarks. The exchange of gluons holds quarks together within a proton or neutron. Excess, or residual, strong force holds together protons and neutrons in the nucleus. The strong nuclear force is strong enough to overcome the electromagnetic force of repulsion pushing protons apart. Both forces are represented in the Figure 1.2. The strong nuclear force works only over very short distances. As a result, it isnt effective if the nucleus gets too big. As more protons are added to the nucleus, the electromagnetic force of repulsion between them gets stronger, while the strong nuclear force of attraction between them gets weaker. This puts an upper limit on the number of protons an atom can have and remain stable. If atoms have more than 83 protons, the electromagnetic repulsion between them is greater than the strong nuclear force of attraction between them. This makes the nucleus unstable, or radioactive, so it breaks down. The following video discusses the strong nuclear force and its role in the atom. The types of quarks found in protons and neutrons are called up quarks (u) and down quarks (d). Each proton consists of two up quarks and one down quark (uud), and each neutron consists of one up quark and two down quarks (udd). This diagram represents two protons. Click image to the left or use the URL below. URL: "
which statement about the strong nuclear force is false?,(A) It can overcome the electromagnetic force pushing protons apart (B) It works over very long distances (C) It is transferred by gluons (D) two of the above,B,"The strong nuclear force is a force of attraction between fundamental particles called quarks, which have a type of charge called color charge. The strong nuclear force is transferred between quarks by fundamental force-carrying particles called gluons. Both protons and neutrons consist of quarks. The exchange of gluons holds quarks together within a proton or neutron. Excess, or residual, strong force holds together protons and neutrons in the nucleus. The strong nuclear force is strong enough to overcome the electromagnetic force of repulsion pushing protons apart. Both forces are represented in the Figure 1.2. The strong nuclear force works only over very short distances. As a result, it isnt effective if the nucleus gets too big. As more protons are added to the nucleus, the electromagnetic force of repulsion between them gets stronger, while the strong nuclear force of attraction between them gets weaker. This puts an upper limit on the number of protons an atom can have and remain stable. If atoms have more than 83 protons, the electromagnetic repulsion between them is greater than the strong nuclear force of attraction between them. This makes the nucleus unstable, or radioactive, so it breaks down. The following video discusses the strong nuclear force and its role in the atom. The types of quarks found in protons and neutrons are called up quarks (u) and down quarks (d). Each proton consists of two up quarks and one down quark (uud), and each neutron consists of one up quark and two down quarks (udd). This diagram represents two protons. Click image to the left or use the URL below. URL: "
the weak nuclear force is transferred by w and z bosons.,(A) true (B) false,A,"The weak nuclear force is transferred by the exchange of force-carrying fundamental particles called W and Z bosons. This force is also a very short-range force that works only within the nucleus of the atom. It is much weaker than the strong force or electromagnetic force that are also at work inside the atom. Unlike these other two forces, the weak nuclear force does not bind subatomic particles together in an atom. Instead, it changes subatomic particles from one type to another. The Figure 1.3 shows one way this can happen. In this figure, an up quark in a proton is changed by the weak force to a down quark. This changes the proton (uud) to a neutron (udd). Q: If the weak force causes a proton to change to a neutron, how does this change the atom? A: The resulting atom represents a different element. Thats because each element has a unique number of protons. For example, all atoms of helium have two protons. If one of the protons in a helium atom changes to a neutron, the resulting atom would have just one proton, so the atom would no longer be a helium atom. Instead it would be a hydrogen atom, because all hydrogen atoms have a single proton. "
up quarks can change to down quarks.,(A) true (B) false,A,"The weak nuclear force is transferred by the exchange of force-carrying fundamental particles called W and Z bosons. This force is also a very short-range force that works only within the nucleus of the atom. It is much weaker than the strong force or electromagnetic force that are also at work inside the atom. Unlike these other two forces, the weak nuclear force does not bind subatomic particles together in an atom. Instead, it changes subatomic particles from one type to another. The Figure 1.3 shows one way this can happen. In this figure, an up quark in a proton is changed by the weak force to a down quark. This changes the proton (uud) to a neutron (udd). Q: If the weak force causes a proton to change to a neutron, how does this change the atom? A: The resulting atom represents a different element. Thats because each element has a unique number of protons. For example, all atoms of helium have two protons. If one of the protons in a helium atom changes to a neutron, the resulting atom would have just one proton, so the atom would no longer be a helium atom. Instead it would be a hydrogen atom, because all hydrogen atoms have a single proton. "
the nucleus contains,(A) protons (B) neutrons (C) electrons (D) two of the above,D,"The nucleus is only found in eukaryotic cells. It contains most of the genetic material (the DNA) of the cell. The genetic material of the nucleus is like a set of instructions. These instructions tell the cell how to build molecules needed for the cell to function properly. That is, the DNA tells the cell how to build molecules needed for life. The nucleus is surrounded by the nuclear envelope, a double membrane (two phospholipid bilayers) that controls what goes in and out of the nucleus. The nucleus also has holes embedded in the nuclear envelope. These holes are known as nuclear pores, and they allow things to flow in and out of the nucleus. "
"outside of the nucleus, an atom is mostly empty space.",(A) true (B) false,A,"The nucleus (plural, nuclei) is a positively charged region at the center of the atom. It consists of two types of subatomic particles packed tightly together. The particles are protons, which have a positive electric charge, and neutrons, which are neutral in electric charge. Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it. The Figure 1.1 shows these parts of the atom. "
the nucleus makes up about 1/100th of the total radius of an atom.,(A) true (B) false,B,"The nucleus of the atom is extremely small. Its radius is only about 1/100,000 of the total radius of the atom. If an atom were the size of a football stadium, the nucleus would be about the size of a pea! Click image to the left or use the URL below. URL:  Electrons have virtually no mass, but protons and neutrons have a lot of mass for their size. As a result, the nucleus has virtually all the mass of an atom. Given its great mass and tiny size, the nucleus is very dense. If an object the size of a penny had the same density as the nucleus of an atom, its mass would be greater than 30 million tons! Click image to the left or use the URL below. URL: "
the nucleus has almost all of the mass of an atom.,(A) true (B) false,A,"The nucleus of the atom is extremely small. Its radius is only about 1/100,000 of the total radius of the atom. If an atom were the size of a football stadium, the nucleus would be about the size of a pea! Click image to the left or use the URL below. URL:  Electrons have virtually no mass, but protons and neutrons have a lot of mass for their size. As a result, the nucleus has virtually all the mass of an atom. Given its great mass and tiny size, the nucleus is very dense. If an object the size of a penny had the same density as the nucleus of an atom, its mass would be greater than 30 million tons! Click image to the left or use the URL below. URL: "
what force holds together the nucleus?,(A) The force of attraction between positive and negative particles (B) The force of attraction between the nucleus and electrons (C) The strong nuclear force between protons and neutrons (D) The weak atomic force between neutrons and electrons,C,"The strong nuclear force is a force of attraction between fundamental particles called quarks, which have a type of charge called color charge. The strong nuclear force is transferred between quarks by fundamental force-carrying particles called gluons. Both protons and neutrons consist of quarks. The exchange of gluons holds quarks together within a proton or neutron. Excess, or residual, strong force holds together protons and neutrons in the nucleus. The strong nuclear force is strong enough to overcome the electromagnetic force of repulsion pushing protons apart. Both forces are represented in the Figure 1.2. The strong nuclear force works only over very short distances. As a result, it isnt effective if the nucleus gets too big. As more protons are added to the nucleus, the electromagnetic force of repulsion between them gets stronger, while the strong nuclear force of attraction between them gets weaker. This puts an upper limit on the number of protons an atom can have and remain stable. If atoms have more than 83 protons, the electromagnetic repulsion between them is greater than the strong nuclear force of attraction between them. This makes the nucleus unstable, or radioactive, so it breaks down. The following video discusses the strong nuclear force and its role in the atom. The types of quarks found in protons and neutrons are called up quarks (u) and down quarks (d). Each proton consists of two up quarks and one down quark (uud), and each neutron consists of one up quark and two down quarks (udd). This diagram represents two protons. Click image to the left or use the URL below. URL: "
there is an electric force of repulsion between neutrons and protons.,(A) true (B) false,B,"Particles with opposite electric charges attract each other. This explains why negative electrons orbit the positive nucleus. Particles with the same electric charge repel each other. This means that the positive protons in the nucleus push apart from one another. So why doesnt the nucleus fly apart? An even stronger forcecalled the strong nuclear forceholds protons and neutrons together in the nucleus. Click image to the left or use the URL below. URL:  Q: Can you guess why an atomic bomb releases so much energy when it explodes? A: When an atomic bomb explodes, the nuclei of atoms undergo a process called fission, in which they split apart. This releases the huge amount of energy that was holding together subatomic particles in the nucleus. "
all atoms of a given element have the same number of protons.,(A) true (B) false,A,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
atoms of different elements always have different numbers of protons.,(A) true (B) false,A,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
which statement about the mass of subatomic particles is false?,(A) A proton has a mass of 1 amu (B) A neutron has slightly more mass than a proton (C) An electron has slightly less mass than a proton (D) none of the above,C,"Based on their knowledge of subatomic particles, scientists have developed a theory called the standard model to explain all the matter in the universe and how it is held together. The model includes only the fundamental particles in the Table 1.2. No other particles are needed to explain all kinds of matter. According to the model, all known matter consists of quarks and leptons that interact by exchanging bosons, which transmit fundamental forces. The standard model is a good theory because all of its predictions have been verified by experimental data. However, the model doesnt explain everything, including the force of gravity and why matter has mass. Scientists continue to search for evidence that will allow them to explain these aspects of force and matter as well. "
a carbon atom has six protons and six neutrons. what is its atomic number?,(A) 6 (B) 12 (C) 36 (D) none of the above,A,"Find carbon in the Figure 1.1, and youll see that its atomic number is 6. This means that all carbon atoms have 6 protons per nucleus. Almost all carbon atoms also have 6 neutrons per nucleus. These carbon atoms are called carbon-12, where 12 is the number of protons (6) plus neutrons (6). This gives carbon-12 nuclei a 1:1 ratio of protons to neutrons, so carbon-12 nuclei are stable. Some carbon atoms have more than 6 neutrons, either 7 or 8. Carbon atoms with 8 neutrons are called carbon-14 (6 protons + 8 neutrons). The nuclei of carbon-14 atoms are unstable because they have too many neutrons relative to protons, so they gradually decay. Q: What is the proton-to-neutron ratio of carbon-14 nuclei? A: With six protons and 8 neutrons, the ratio is 6:8, or 1:1.3. Q: How is carbon-14 used to estimate the ages of fossils? A: Living things take in carbon, including tiny amounts of carbon-14, throughout life. The carbon-14 constantly decays, but more carbon-14 is taken in all the time to replace it. After living things die, no new carbon-14 is taken in, and the carbon-14 they already have keeps decaying. The older a fossil is, the less carbon-14 it still has, so the remaining amount can be measured to estimate the fossils age. Click image to the left or use the URL below. URL:  Periodic Table of the Elements "
what is the mass number of the carbon atom in question 8?,(A) 6 (B) 12 (C) 18 (D) 72,B,"For most other elements, isotopes are named for their mass number. For example, carbon atoms with the usual 6 neutrons have a mass number of 12 (6 protons + 6 neutrons = 12), so they are called carbon-12. Carbon atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms are the isotope called carbon-13. Some carbon atoms have 8 neutrons. What is the name of this isotope of carbon? You can learn more about this isotope at the URL below. It is used by scientists to estimate the ages of rocks and fossils. "
which of the following is the general form of a chemical equation?,(A) Reactants = Products (B) Products + Reactants = 100% (C) Products → Reactants (D) Reactants → Products,D,"A chemical equation is a shorthand way to sum up what occurs in a chemical reaction. The general form of a chemical equation is: Reactants  Products The reactants in a chemical equation are the substances that begin the reaction, and the products are the substances that are produced in the reaction. The reactants are always written on the left side of the equation and the products on the right. The arrow pointing from left to right shows that the reactants change into the products during the reaction. This happens when chemical bonds break in the reactants and new bonds form in the products. As a result, the products are different chemical substances than the reactants that started the reaction. Q: What is the general equation for the reaction in which iron rusts? A: Iron combines with oxygen to produce rust, which is the compound named iron oxide. This reaction could be represented by the general chemical equation below. Note that when there is more than one reactant, they are separated by plus signs (+). If more than one product were produced, plus signs would be used between them as well. Iron + Oxygen  Iron Oxide "
which of the following equations is balanced?,(A) H2 + O2 → H2O (B) 2H2 + O2 → 2H2O (C) H2 + 2O2 → 2H2O (D) 2H2 + O2 → H2O,B,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
numbers called subscripts are used to balance chemical equations.,(A) true (B) false,B,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
which of the following rules should you follow to balance chemical equations?,(A) Change only the subscripts (B) Use the smallest possible subscripts (C) Add coefficients as needed (D) two of the above,C,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
which coefficient will balance the following equation? zn + hcl  zncl2 + h2,(A) 2 (B) 3 (C) 4 (D) none of the above,A,"Coefficients are used to balance chemical equations. A coefficient is a number placed in front of a chemical symbol or formula. It shows how many atoms or molecules of the substance are involved in the reaction. For example, two molecules of hydrogen would be written as 2H2 . A coefficient of 1 usually isnt written. Coefficients can be used to balance equation 1 (above) as follows: Equation 2: 2H2 + O2 ! 2H2 O Equation 2 shows that two molecules of hydrogen react with one molecule of oxygen to produce two molecules of water. The two molecules of hydrogen each contain two hydrogen atoms. There are now four hydrogen atoms in both reactants and products. Is equation 2 balanced? Count the oxygen atoms to find out. "
which particle is emitted from a nucleus when it undergoes beta-minus decay?,(A) electron (B) positron (C) anti-electron (D) proton,A,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron. An electron is a negatively charged particle, and a positron is a positively charged electron (or anti- electron). When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay. Beta-minus decay occurs when a nucleus has too many neutrons relative to protons, and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons, so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay? A: Beta decay begins with a proton or neutron. You can see how in the Figure 1.1. Q: How does beta decay change an atom to a different element? A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton. In each case, the atom becomes a different element because it has a different number of protons. "
beta-positive decay begins with a proton.,(A) true (B) false,A,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron. An electron is a negatively charged particle, and a positron is a positively charged electron (or anti- electron). When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay. Beta-minus decay occurs when a nucleus has too many neutrons relative to protons, and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons, so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay? A: Beta decay begins with a proton or neutron. You can see how in the Figure 1.1. Q: How does beta decay change an atom to a different element? A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton. In each case, the atom becomes a different element because it has a different number of protons. "
"in the following symbol for a beta-minus particle, what does the superscript represent?",(A) charge (B) mass (C) energy (D) none of the above,B,"Radioactive nuclei and particles are represented by nuclear symbols.. For example, a beta-minus particle (electron) is represented by the symbol 01 e. The subscript -1 represents the particles charge, and the superscript 0 shows that the particle has virtually no mass (no protons or neutrons). Another example is the radioactive nucleus of thorium-234. It is represented by the symbol 234 90 Th, where the subscript 90 stands for the number of protons and the superscript 234 for the number of protons plus neutrons. Nuclear symbols are used to write nuclear equations for radioactive decay. Lets consider the example of the beta- minus decay of thorium-234 to protactinium-234. This reaction is represented by the equation: 234 Th 90 0 234 91 Pa + 1 e + energy The equation shows that thorium-234 becomes protactinium-234 and loses a beta particle and energy. The protactinium- 234 produced in the reaction is also radioactive, so it will decay as well. A nuclear equation is balanced if the total numbers of protons and neutrons are the same on both sides of the arrow. If you compare the subscripts and superscripts on both sides of the equation above, youll see that they are the same. Q: What happens to the electron produced in the reaction above? A: Along with another electron, it can combine with an alpha particle to form a helium atom. An alpha particle, which is emitted during alpha decay, consists of two protons and two neutrons. Q: Try to balance the following nuclear equation for beta-minus decay by filling in the missing subscript and superscript. 131 I 53 ?? Xe + 01 e + energy A: The subscript of Xe is 54, and the superscript is 131. "
beta particles can travel only a few centimeters through the air.,(A) true (B) false,B,Beta particles can travel about a meter through air. They can pass through a sheet of paper or a layer of cloth but not through a sheet of aluminum or a few centimeters of wood. They can also penetrate the skin and damage underlying tissues. They are even more harmful if they are ingested or inhaled. 
beta-positive decay results in a nucleus with one less proton.,(A) true (B) false,A,"Beta decay occurs when an unstable nucleus emits a beta particle and energy. A beta particle is either an electron or a positron. An electron is a negatively charged particle, and a positron is a positively charged electron (or anti- electron). When the beta particle is an electron, the decay is called beta-minus decay. When the beta particle is a positron, the decay is called beta-plus decay. Beta-minus decay occurs when a nucleus has too many neutrons relative to protons, and beta-plus decay occurs when a nucleus has too few neutrons relative to protons. Q: Nuclei contain only protons and neutrons, so how can a nucleus emit an electron in beta-minus decay or a positron in beta-plus decay? A: Beta decay begins with a proton or neutron. You can see how in the Figure 1.1. Q: How does beta decay change an atom to a different element? A: In beta-minus decay an atom gains a proton, and it beta-plus decay it loses a proton. In each case, the atom becomes a different element because it has a different number of protons. "
there are only about 100 different biochemical compounds.,(A) true (B) false,B,All known matter can be divided into a little more than 100 different substances called elements. 
the similarity in biochemical compounds between living things provides some of the best evidence for evolution.,(A) true (B) false,A,"Scientists have learned a lot about evolution by comparing living organisms. They have compared body parts, embryos, and molecules such as DNA and proteins. "
functions of carbohydrates include,(A) storing energy in plants (B) storing energy in animals (C) making up cell walls in plants (D) two of the above,D,"Carbohydrates are biochemical compounds that include sugars, starches, and cellulose. They contain oxygen in addition to carbon and hydrogen. Organisms use carbohydrates mainly for energy. "
functions of nucleic acids include,(A) storing genetic information in cells (B) speeding up biochemical reactions (C) regulating life processes (D) all of the above,A,"Nucleic acids are biochemical molecules that contain oxygen, nitrogen, and phosphorus in addition to carbon and hydrogen. There are two main types of nucleic acids. They are DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). "
elements found in proteins but not in other biochemical compounds include,(A) sulfur (B) nitrogen (C) phosphorus (D) two of the above,A,"Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. "
almost all biochemical compounds are polymers.,(A) true (B) false,A,"You can see from Table 2.1 that all biochemical compounds contain hydrogen and oxygen as well as carbon. They may also contain nitrogen, phosphorus, and/or sulfur. Almost all biochemical compounds are polymers. Polymers are large molecules that consist of many smaller, repeating molecules, called monomers. Most biochemical molecules are macromolecules. The prefix macro- means large, and many biochemical molecules are very large indeed. They may contain thousands of monomer molecules. The largest known biochemical molecule contains more than 34,000 monomers! "
catabolic reactions are chemical reactions in living things that,(A) release energy (B) are endothermic (C) break bonds (D) two of the above,D,"Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. Catabolic reactions involve breaking bonds. Larger molecules are broken down to smaller ones. For example, complex carbohydrates are broken down to simple sugars. Catabolic reactions release energy, so they are exothermic. Anabolic reactions involve forming bonds. Smaller molecules are combined to form larger ones. For example, simple sugars are combined to form complex carbohydrates. Anabolic reactions require energy, so they are endothermic. Q: Imagine! Each of the trillions of cells in your body is continuously performing thousands of catabolic and anabolic reactions. Thats an amazing number of biochemical reactionsfar more than the number of reactions that might take place in a lab or factory. How can so many biochemical reactions take place simultaneously in our cells? A: So many reactions can occur because biochemical reactions are amazingly fast. Q: In a lab or factory, reactants can be heated to very high temperatures or placed under great pressure so they will react very quickly. These ways of speeding up chemical reactions cant occur inside the delicate cells of living things. So how do cells speed up biochemical reactions? A: The answer is enzymes. "
anabolic reactions are chemical reactions in living things that,(A) form larger molecules (B) are exothermic (C) release energy (D) two of the above,A,"The sum of all of an organisms biochemical reactions is called metabolism. Biochemical reactions of metabolism can be divided into two general categories: catabolic reactions and anabolic reactions. You can watch an animation showing how the two categories of reactions are related at this link: Anabolic reactions involve forming bonds. Smaller molecules combine to form larger ones. These reactions require energy. For example, it takes energy to build starches from sugars. Catabolic reactions involve breaking bonds. Larger molecules break down to form smaller ones. These reactions release energy. For example, energy is released when starches break down to sugars. "
the reactants of photosynthesis are oxygen and water.,(A) true (B) false,B,"Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Together, these two processes provide energy to almost all of Earths organisms. The two processes are closely related, as you can see in the Figure 1.1. In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use. A: In photosynthesis, carbon dioxide (CO2 ) and water (H2 O) are the reactants. They combine using energy from light to produce oxygen (O2 ) and glucose (C6 H12 O6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy. "
photosynthesis is an anabolic reaction.,(A) true (B) false,A,Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Photosynthesis is the process in which producers capture light energy from the sun and use it to make glucose. This involves anabolic reactions. Cellular respiration is the process in which energy is released from glucose and stored in smaller amounts in other molecules that cells can use for energy. This involves catabolic reactions. Photosynthesis and cellular respiration together provide energy to almost all living cells. Figure 2.14 shows how photosynthesis and cellular respiration are related. You can read more about both processes in the chapter Cell Functions. 
cellular respiration is a catabolic reaction.,(A) true (B) false,A,"The reactions of cellular respiration are catabolic reactions. In catabolic reactions, bonds are broken in larger molecules and energy is released. In cellular respiration, bonds are broken in glucose, and this releases the chemical energy that was stored in the glucose bonds. Some of this energy is converted to heat. The rest of the energy is used to form many small molecules of a compound called adenosine triphosphate, or ATP. ATP molecules contain just the right amount of stored chemical energy to power biochemical reactions inside cells. Click image to the left or use the URL below. URL: "
electrons with the most energy are located closest to the nucleus of the atom.,(A) true (B) false,B,"Electrons are located at fixed distances from the nucleus, called energy levels. You can see the first three energy levels in the Figure 1.3. The diagram also shows the maximum possible number of electrons at each energy level. Electrons at lower energy levels, which are closer to the nucleus, have less energy. At the lowest energy level, which has the least energy, there is just one orbital, so this energy level has a maximum of two electrons. Only when a lower energy level is full are electrons added to the next higher energy level. Electrons at higher energy levels, which are farther from the nucleus, have more energy. They also have more orbitals and greater possible numbers of electrons. Electrons at the outermost energy level of an atom are called valence electrons. They determine many of the properties of an element. Thats because these electrons are involved in chemical reactions with other atoms. Atoms may share or transfer valence electrons. Shared electrons bind atoms together to form chemical compounds. Q: If an atom has 12 electrons, how will they be distributed in energy levels? A: The atom will have two electrons at the first energy level, eight at the second energy level, and the remaining two at the third energy level. Q: Sometimes, an electron jumps from one energy level to another. How do you think this happens? A: To change energy levels, an electron must either gain or lose energy. Thats because electrons at higher energy levels have more energy than electrons at lower energy levels. "
"bohr hypothesized that if an electron gained just the right amount of energy, it would",(A) jump to the next higher energy level (B) drop down to the next lower energy level (C) move halfway to the next higher energy level (D) crash into the nucleus of the atom,A,"As a young man, Bohr worked in Rutherfords lab in England. Because Rutherfords model was weak on the position of the electrons, Bohr focused on them. He hypothesized that electrons can move around the nucleus only at fixed distances from the nucleus based on the amount of energy they have. He called these fixed distances energy levels, or electron shells. He thought of them as concentric spheres, with the nucleus at the center of each sphere. In other words, the shells consisted of sphere within sphere within sphere. Furthermore, electrons with less energy would be found at lower energy levels, closer to the nucleus. Those with more energy would be found at higher energy levels, farther from the nucleus. Bohr also hypothesized that if an electron absorbed just the right amount of energy, it would jump to the next higher energy level. Conversely, if it lost the same amount of energy, it would jump back to its original energy level. However, an electron could never exist in between two energy levels. These ideas are illustrated in the Figure 1.2. Q: How is an atom like a ladder? A: Energy levels in an atom are like the rungs of a ladder. Just as you can stand only on the rungs and not in between them, electrons can orbit the nucleus only at fixed distances from the nucleus and not in between them. "
the idea of the quantum was first introduced by,(A) Bohr (B) Planck (C) Thomson (D) Rutherford,B,"Bohrs model of the atom is actually a combination of two different ideas: Rutherfords atomic model of electrons orbiting the nucleus and German scientist Max Plancks idea of a quantum, which Planck published in 1901. A quantum (plural, quanta) is the minimum amount of energy that can be absorbed or released by matter. It is a discrete, or distinct, amount of energy. If energy were water and you wanted to add it to matter in the form of a drinking glass, you couldnt simply pour the water continuously into the glass. Instead, you could add it only in small fixed quantities, for example, by the teaspoonful. Bohr reasoned that if electrons can absorb or lose only fixed quantities of energy, then they must vary in their energy by these fixed amounts. Thus, they can occupy only fixed energy levels around the nucleus that correspond to quantum increases in energy. This is a two-dimensional model of a three-dimensional atom. The concen- tric circles actually represent concentric spheres. Q: The idea that energy is transferred only in discrete units, or quanta, was revolutionary when Max Planck first proposed it in 1901. However, what scientists already knew about matter may have made it easier for them to accept the idea of energy quanta. Can you explain? A: Scientists already knew that matter exists in discrete units called atoms. This idea had been demonstrated by John Dalton around 1800. Knowing this may have made it easier for scientists to accept the idea that energy exists in discrete units as well. "
energy levels around the atomic nucleus correspond to quantum increases in energy.,(A) true (B) false,A,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
which type(s) of chemical bonds may be polar bonds?,(A) ionic bonds (B) metallic bonds (C) covalent bonds (D) two of the above,C,"In some covalent bonds, electrons are not shared equally between the two atoms. These are called polar bonds. Figure 7.9 shows this for water. The oxygen atom attracts the shared electrons more strongly because its nucleus has more positively charged protons. As a result, the oxygen atom becomes slightly negative in charge. The hydrogen atoms attract the electrons less strongly. They become slightly positive in charge. For another example of polar bonds, see the video at this URL:  (0:52). MEDIA Click image to the left or use the URL below. URL:  In other covalent bonds, electrons are shared equally. These bonds are called nonpolar bonds. Neither atom attracts the shared electrons more strongly. As a result, the atoms remain neutral. Figure 7.10 shows an example of nonpolar bonds. "
which of the following molecules has (have) polar bonds?,(A) water (B) carbon dioxide (C) formaldehyde (D) all of the above,D,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
all molecules with polar bonds are polar molecules.,(A) true (B) false,B,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
the oxygen end of a water molecule is positively charged.,(A) true (B) false,B,"Water is simply two atoms of hydrogen and one atom of oxygen bonded together (Figure 1.1). The hydrogen ions are on one side of the oxygen ion, making water a polar molecule. This means that one side, the side with the hydrogen ions, has a slightly positive electrical charge. The other side, the side without the hydrogen ions, has a slightly negative charge. Despite its simplicity, water has remarkable properties. Water expands when it freezes, has high surface tension (because of the polar nature of the molecules, they tend to stick together), and others. Without water, life might not be able to exist on Earth and it certainly would not have the tremendous complexity and diversity that we see. "
a fluid exerts pressure only in an upward direction.,(A) true (B) false,B,Buoyancy is the ability of a fluid to exert an upward force on any object placed in the fluid. This upward force is called buoyant force. 
fluid pressure is greater at greater depth.,(A) true (B) false,A,"Two factors influence the pressure of fluids. They are the depth of the fluid and its density. A fluid exerts more pressure at greater depths. Deeper in a fluid, all of the fluid above it results in more weight pressing down. This causes greater pressure the deeper you go. Denser fluids such as water exert more pressure than less dense fluids such as air. The particles of denser fluids are closer together, so there are more collisions of particles in a given area. The difference in density of water and air is illustrated in the Figure 1.3. "
the fluid below an object exerts greater force on it than the fluid above the object.,(A) true (B) false,A,"What explains buoyant force? Recall from the earlier lesson ""Pressure of Fluids"" that a fluid exerts pressure in all directions but the pressure is greater at greater depth. Therefore, the fluid below an object exerts greater force on the object than the fluid above the object. This is illustrated in Figure 15.12. Buoyant force explains why objects may float in water. No doubt youve noticed, however, that some objects do not float in water. If buoyant force applies to all objects in fluids, why do some objects sink instead of float? The answer has to do with their weight. "
an object floats in a fluid when the,(A) buoyant force acting on the object is greater than the object’s weight (B) object’s weight is greater than the buoyant force acting on the object (C) object’s weight is the same as buoyant force acting on the object (D) buoyant force acts only under and not above the object,A,Objects such as ships may float in a fluid like water because of buoyant force. This is an upward force that a fluid exerts on any object that is placed in it. Archimedes discovered that the buoyant force acting on an object equals the weight of the fluid displaced by the object. This is known as Archimedes law (or Archimedes principle). 
a denser substance will,(A) float on a less dense fluid (B) sink in a less dense fluid (C) become less dense in a less dense fluid (D) become more dense in a less dense fluid,B,"You are going to visit a friend. You fill one backpack with books so you can study later. You stuff your pillow into another backpack that is the same size. Which backpack will be easier to carry? Even though the backpacks are the same size, the bag that contains your books is going to be much heavier. It has a greater density than the backpack with your pillow. Density describes how much matter is in a certain amount of space. Substances that have more matter packed into a given space have higher densities. The water in a drinking glass has the same density as the water in a bathtub or swimming pool. All substances have characteristic densities, which does not depend on how much of a substance you have. Mass is a measure of the amount of matter in an object. The amount of space an object takes up is described by its volume. The density of an object depends on its mass and its volume. Density can be calculated using the following equation: Density = Mass/Volume Samples that are the same size, but have different densities, will have different masses. Gold has a density of about 19 g/cm3 . Pyrite has a density of only about 5 g/cm3 . Quartz is even less dense than pyrite, and has a density of 2.7 g/cm3 . If you picked up a piece of pyrite and a piece of quartz that were the same size, the pyrite would seem almost twice as heavy as the quartz. "
any change in an objects motion is called velocity.,(A) true (B) false,B,"In science, motion is defined as a change in position. An objects position is its location. Besides the wings of the hummingbird in the opening image, you can see other examples of motion in the Figure 1.1. In each case, the position of something is changing. Q: In each picture in the Figure 1.1, what is moving and how is its position changing? A: The train and all its passengers are speeding straight down a track to the next station. The man and his bike are racing along a curving highway. The geese are flying over their wetland environment. The meteor is shooting through the atmosphere toward Earth, burning up as it goes. "
"the greater the net force acting on an object, the greater its acceleration will be.",(A) true (B) false,A,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
"for a given net force, an object will accelerate less if it has a greater",(A) mass (B) volume (C) speed (D) none of the above,A,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
one newton is the force needed to cause a,(A) 1-kg object to accelerate at 1 m/s2 (B) 1-g object to accelerate at 1 cm/s2 (C) 1-kg object to accelerate at 1 km/s2 (D) none of the above,A,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
the si unit for acceleration is,(A) cm/s2 (B) m/s2 (C) km/s2 (D) none of the above,B,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
which equation is used to calculate average acceleration when only speed is changing?,(A) average acceleration = Δv/Δt (B) average acceleration = Δt/Δv (C) average acceleration = Δd/Δt (D) average acceleration = v/Δt,A,"Calculating acceleration is complicated if both speed and direction are changing or if you want to know acceleration at any given instant in time. However, its relatively easy to calculate average acceleration over a period of time when only speed is changing. Then acceleration is the change in velocity (represented by v) divided by the change in time (represented by t): acceleration = v t "
it is easier to calculate acceleration for any given moment of time than to calculate average acceleration for a period of time.,(A) true (B) false,B,"Calculating acceleration is complicated if both speed and direction are changing or if you want to know acceleration at any given instant in time. However, its relatively easy to calculate average acceleration over a period of time when only speed is changing. Then acceleration is the change in velocity (represented by v) divided by the change in time (represented by t): acceleration = v t "
the si unit for acceleration is,(A) m/s (B) m/s2 (C) m/s2 (D) none of the above,C,"The SI unit of force is the newton (N). One newton is the amount of force that causes a mass of 1 kilogram to accelerate at 1 m/s2 . Thus, the newton can also be expressed as kgm/s2 . The newton was named for the scientist Sir Isaac Newton, who is famous for his law of gravity. Youll learn more about Sir Isaac Newton later in the chapter. "
which of the following units could represent acceleration?,(A) cm/s (B) km/h2 (C) m/h (D) cm/h,B,"This equation for acceleration can be used to calculate the acceleration of an object that is acted on by a net force. For example, Xander and his scooter have a total mass of 50 kilograms. Assume that the net force acting on Xander and the scooter is 25 Newtons. What is his acceleration? Substitute the relevant values into the equation for acceleration: F = 25 N = 0.5 N a= m 50 kg kg The Newton is the SI unit for force. It is defined as the force needed to cause a 1-kilogram mass to accelerate at 1 m/s2 . Therefore, force can also be expressed in the unit kg  m/s2 . This way of expressing force can be substituted for Newtons in Xanders acceleration so the answer is expressed in the SI unit for acceleration, which is m/s2 : 2 0.5 kgm/s a = 0.5kgN = = 0.5 m/s2 kg Q: Why are there no kilograms in the final answer to this problem? A: The kilogram units in the numerator and denominator of the fraction cancel out. As a result, the answer is expressed in the correct SI units for acceleration. "
"when calculating work, force is measured in",(A) joules (B) Newtons (C) foot-pounds (D) none of the above,B,"The equation for work can be used to calculate work if force and distance are known. To use the equation, force is expressed in Newtons (N), and distance is expressed in meters (m). For example, assume that Clarissa uses 100 Newtons of force to push the mower and that she pushes it for a total of 200 meters as she cuts the grass in her grandmothers yard. Then, the amount of work Clarissa does is: Work = 100 N  200 m = 20,000 N  m Notice that the unit for work in the answer is the Newton  meter (N  m). This is the SI unit for work, also called the joule (J). One joule equals the amount of work that is done when 1 N of force moves an object over a distance of 1 m. Q: After Clarissa mows her grandmothers lawn, she volunteers to mow a neighbors lawn as well. If she pushes the mower with the same force as before and moves it over a total of 234 meters, how much work does she do mowing the neighbors lawn? A: The work Clarissa does can be calculated as: Work = 100 N  234 m = 23,400 N  m, or 23,400 J "
one joule equals the amount of work that is done when 1 n of force moves an object over a distance of,(A) 1 cm (B) 1 m (C) 1 km (D) none of the above,B,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
you can calculate force from work and distance with the equation,(A) Force = Work x Distance (B) Force = Work/Distance (C) Force = Distance/Work (D) Force = Work + Distance,B,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
you can calculate distance from work and force with the equation,(A) Distance = Work x Force (B) Distance = Work/Force (C) Distance = Force/Work (D) Distance = Work + Force,B,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
carbohydrates consist of atoms of,(A) carbon (B) hydrogen (C) oxygen (D) all of the above,D,"Carbohydrates are one of four classes of biochemical compounds. The other three classes are proteins, lipids, and nucleic acids. In addition to cellulose, carbohydrates include sugars and starches. Carbohydrate molecules contain atoms of carbon, hydrogen, and oxygen. Living things use carbohydrates mainly for energy. Q: Which carbohydrates do you use for energy? A: You may eat a wide variety of carbohydratesfrom sugars in fruits to starches in potatoes. However, body cells use only sugars for energy. "
plants stores extra glucose as starches.,(A) true (B) false,A,"Starches are complex carbohydrates. They are polymers of glucose. They consist of hundreds of glucose monomers bonded together. Plants make starch to store extra sugars. Consumers get starch from plants. Common sources of starch in the human diet are pictured in Figure 9.17. Our digestive system breaks down starch to simple sugars, which our cells use for energy. "
cellulose is a polymer of starch.,(A) true (B) false,B,"Cellulose is another complex carbohydrate that is a polymer of glucose. However, glucose molecules are bonded together differently in cellulose than they are in starches. Cellulose molecules bundle together to form long, tough fibers, as you can see in the Figure 1.3. Have you ever eaten raw celery? If you have, then you probably noticed that Foods that are good sources of starches. the stalks contain long, stringy fibers. The fibers are mostly cellulose. Cellulose is the most abundant biochemical compound. It makes up the cell walls of plants and gives support to stems and tree trunks. Cellulose also provides needed fiber in the human diet. We cant digest cellulose, but it helps keep food wastes moving through the digestive tract. "
about half of all known compounds contain carbon.,(A) true (B) false,B,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
how many chemical bonds can each carbon atom form?,(A) 1 (B) 2 (C) 3 (D) 4,D,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
methane is an example of a hydrocarbon.,(A) true (B) false,A,"A carbon atom can form covalent bonds with other carbon atoms or with the atoms of other elements. Carbon often forms bonds with hydrogen. Compounds that contain only carbon and hydrogen are called hydrocarbons. Methane (CH4 ), which is modeled in the Figure 1.2, is an example of a hydrocarbon. In methane, a single carbon atom forms covalent bonds with four hydrogen atoms. The diagram on the left in the Figure 1.2 shows all the shared valence electrons. The diagram on the right in the Figure 1.2, called a structural formula, represents each pair of shared electrons with a dash (-). Methane (CH4 ) "
carbon forms triple bonds with other carbon atoms in the compound named,(A) ethane (B) ethene (C) ethyne (D) two of the above,C,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
"when two carbon atoms form triple bonds, how many electrons do they share?",(A) 3 (B) 4 (C) 5 (D) 6,D,"Carbon can form single, double, or even triple bonds with other carbon atoms. In a single bond, two carbon atoms share one pair of electrons. In a double bond, they share two pairs of electrons, and in a triple bond they share three pairs of electrons. Examples of compounds with these types of bonds are shown in Figure 9.3. "
carbon can form more compounds than any other element.,(A) true (B) false,A,"Carbon is a very common ingredient of matter because it can combine with itself and with many other elements. It can form a great diversity of compounds, ranging in size from just a few atoms to thousands of atoms. There are millions of known carbon compounds, and carbon is the only element that can form so many different compounds. "
examples of naturally occurring carbon polymers include,(A) cellulose (B) rubber (C) plastic (D) two of the above,D,"Many polymers of carbon occur naturally. Two examples are rubber and cellulose. Rubber is a natural polymer of the monomer named isoprene (C5 H8 ). This polymer comes from rubber trees, which grow in tropical areas. Structural formulas for rubber and isoprene are shown in the Figure 1.2. Note that just a small section of the rubber polymer is represented by the structural formula. Cellulose is a natural polymer of the monomer named glucose (C6 H12 O6 ). This polymer makes up the cell walls of plants and is the most common compound in living things. Structural formulas for cellulose and glucose are also shown in the Figure 1.2). As you can see from the structural formula for cellulose, when two glucose monomers bond together, a molecule of water (H2 O) is released. Q: How are the glucose molecules arranged in the cellulose polymer? A: The glucose molecules alternate between right-side up and upside down. "
rubber consists of the monomer named ethylene.,(A) true (B) false,B,"Many polymers of carbon occur naturally. Two examples are rubber and cellulose. Rubber is a natural polymer of the monomer named isoprene (C5 H8 ). This polymer comes from rubber trees, which grow in tropical areas. Structural formulas for rubber and isoprene are shown in the Figure 1.2. Note that just a small section of the rubber polymer is represented by the structural formula. Cellulose is a natural polymer of the monomer named glucose (C6 H12 O6 ). This polymer makes up the cell walls of plants and is the most common compound in living things. Structural formulas for cellulose and glucose are also shown in the Figure 1.2). As you can see from the structural formula for cellulose, when two glucose monomers bond together, a molecule of water (H2 O) is released. Q: How are the glucose molecules arranged in the cellulose polymer? A: The glucose molecules alternate between right-side up and upside down. "
any given polymer consists of just one type of monomer.,(A) true (B) false,B,"Carbon has a unique ability to form covalent bonds with many other atoms. It can bond with other carbon atoms as well as with atoms of other elements. Because of this ability, carbon often forms polymers. A polymer is a large molecule that is made out of many smaller molecules that are joined together by covalent bonds. The smaller, repeating molecules are called monomers. (The prefix mono- means one and the prefix poly- means many.) Polymers may consist of just one type of monomer or of more than one type. Polymers are similar to the strings of beads pictured in the Figure 1.1. Like beads on a string, monomers in a polymer may be all the same or different from one another. "
a catalyst is a reactant in the reaction it catalyzes.,(A) true (B) false,B,"A catalyst is a substance that increases the rate of a chemical reaction. The presence of a catalyst is one of several factors that influence the rate of chemical reactions. (Other factors include the temperature, concentration, and surface area of reactants.) A catalyst isnt a reactant in the chemical reaction it speeds up. As a result, it isnt changed or used up in the reaction, so it can go on to catalyze many more reactions. Q: How is a catalyst like a tunnel through a mountain? A: Like a tunnel through a mountain, a catalyst provides a faster pathway for a chemical reaction to occur. "
a catalyst is used up in the reaction it catalyzes.,(A) true (B) false,B,"Some reactions need extra help to occur quickly. They need another substance, called a catalyst. A catalyst is a substance that increases the rate of a chemical reaction but is not changed or used up in the reaction. The catalyst can go on to catalyze many more reactions. Catalysts are not reactants, but they help reactants come together so they can react. You can see one way this happens in the animation at the URL below. By helping reactants come together, a catalyst decreases the activation energy needed to start a chemical reaction. This speeds up the reaction. Living things depend on catalysts to speed up many chemical reactions inside their cells. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take billions of years without it! "
the compound that speeds up the breakdown of starch to sugar in your mouth is,(A) an enzyme (B) called amylase (C) also found in your small intestine (D) all of the above,D,"The mouth is the first digestive organ that food enters. The sight, smell, or taste of food stimulates the release of saliva and digestive enzymes by salivary glands inside the mouth. Saliva wets the food, which makes it easier to break up and swallow. The enzyme amylase in saliva begins the chemical digestion of starches to sugars. Your teeth help to mechanically digest food. Look at the different types of human teeth in Figure 17.13. Sharp teeth in the front of the mouth cut or tear food when you bite into it. Broad teeth in the back of the mouth grind food when you chew. Your tongue helps mix the food with saliva and enzymes and also helps you swallow. When you swallow, a lump of chewed food passes from the mouth into a tube in your throat called the pharynx. From the pharynx, the food passes into the esophagus. "
more than 1000 different enzymes are necessary for human life.,(A) true (B) false,A,More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. Two examples are amylase and pepsin. Both are described in the Figure 1.2. 
the presence or absence of a catalyst is the only factor that affects the rate of a chemical reaction.,(A) true (B) false,B,How fast a chemical reaction occurs is called the reaction rate. Several factors affect the rate of a given chemical reaction. They include the: temperature of reactants. concentration of reactants. surface area of reactants. presence of a catalyst. 
organisms that make glucose are called autotrophs.,(A) true (B) false,A,"Types of organisms that make glucose by photosynthesis are pictured in Figure 4.7. They include plants, plant-like protists such as algae, and some kinds of bacteria. Living things that make glucose are called autotrophs (""self feeders""). All other living things obtain glucose by eating autotrophs (or organisms that eat autotrophs). These living things are called heterotrophs (""other feeders""). "
cellular respiration takes place only in the cells of heterotrophs.,(A) true (B) false,B,"Cellular respiration takes place in the cells of all organisms. It occurs in autotrophs such as plants as well as heterotrophs such as animals. Cellular respiration begins in the cytoplasm of cells. It is completed in mitochondria. The mitochondrion is a membrane-enclosed organelle in the cytoplasm. Its sometimes called the ""powerhouse"" of the cell because of its role in cellular respiration. Figure 4.12 shows the parts of the mitochondrion involved in cellular respiration. "
the chemical reactions of cellular respiration are anabolic reactions.,(A) true (B) false,B,Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Photosynthesis is the process in which producers capture light energy from the sun and use it to make glucose. This involves anabolic reactions. Cellular respiration is the process in which energy is released from glucose and stored in smaller amounts in other molecules that cells can use for energy. This involves catabolic reactions. Photosynthesis and cellular respiration together provide energy to almost all living cells. Figure 2.14 shows how photosynthesis and cellular respiration are related. You can read more about both processes in the chapter Cell Functions. 
which compound directly powers biochemical reactions in cells?,(A) glucose (B) carbon dioxide (C) adenosine triphosphate (D) none of the above,C,"Glucose is an example of a biochemical compound. The prefix bio- comes from the Greek word that means life. A biochemical compound is any carbon-based compound that is found in living things. Biochemical compounds make up the cells and tissues of living things. They are also involved in all life processes, including making and using food for energy. Given their diversity of functions, its not surprising that there are millions of different biochemical compounds. Q: Plants make food in the process of photosynthesis. What biochemical compound is synthesized in photosynthe- sis? A: Glucose is synthesized in photosynthesis. Virtually all living things use glucose for energy, but glucose is just one of many examples of biochemical compounds that are found in most or all living things. In fact the similarity in biochemical compounds between living things provides some of the best evidence for the evolution of species from common ancestors. A classic example is the biochemical compound called cytochrome c. It is found in all living organisms because it performs essential life functions. Only slight variations in the molecule exist between closely related species, as you can see in the Figure and the single-celled tetrahymena (pictured in the Figure 1.1), the cytochrome c molecule is nearly 50 percent the same. "
"during cellular respiration, chemical energy stored in glucose changes to",(A) heat (B) light (C) chemical energy in ATP (D) two of the above,D,"Specifically, during cellular respiration, the energy stored in glucose is transferred to ATP ( Figure 1.1). ATP, or adenosine triphosphate, is chemical energy the cell can use. It is the molecule that provides energy for your cells to perform work, such as moving your muscles as you walk down the street. But cellular respiration is slightly more complicated than just converting the energy from glucose into ATP. Cellular respiration can be described as the reverse or opposite of photosynthesis. During cellular respiration, glucose, in the presence of oxygen, is converted into carbon dioxide and water. Recall that carbon dioxide and water are the starting products of photosynthesis. What are the products of photosynthesis? The process can be summarized as: glucose + oxygen  carbon dioxide + water. During this process, the energy stored in glucose is transferred to ATP. Energy is stored in the bonds between the phosphate groups (PO4  ) of the ATP molecule. When ATP is broken down into ADP (adenosine diphosphate) and inorganic phosphate, energy is released. When ADP and inorganic phosphate are joined to form ATP, energy is stored. During cellular respiration, about 36 to 38 ATP molecules are produced for every glucose molecule. The structural formula for adenosine triphosphate (ATP). During cellular respi- ration, energy from the chemical bonds of the food you eat must be transferred to ATP. "
valence electrons are the basis of all chemical bonds.,(A) true (B) false,A,A chemical bond is a force of attraction between atoms or ions. Bonds form when atoms share or transfer valence electrons. Valence electrons are the electrons in the outer energy level of an atom that may be involved in chemical interactions. Valence electrons are the basis of all chemical bonds. Q: Why do you think that chemical bonds form? A: Chemical bonds form because they give atoms a more stable arrangement of electrons. 
"in covalent bonds, atoms",(A) share electrons (B) transfer electrons (C) lose or gain electrons (D) two of the above,A,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
an example of a compound that contains ionic bonds is water.,(A) true (B) false,B,"There are two basic types of compounds that differ in the nature of the bonds that hold their atoms or ions together. They are covalent and ionic compounds. Both types are described below. Click image to the left or use the URL below. URL:  Covalent compounds consist of atoms that are held together by covalent bonds. These bonds form between nonmetals that share valence electrons. Covalent compounds exist as individual molecules. Water is an example of a covalent compound. Ionic compounds consist of ions that are held together by ionic bonds. These bonds form when metals transfer electrons to nonmetals. Ionic compounds exist as a matrix of many ions, called a crystal. Sodium chloride (table salt) is an example of an ionic compound. "
a metallic bond is a bond between a positively charged metal ion and,(A) a negatively charged halogen ion (B) a negatively charged nonmetal ion (C) the valence electrons of several metal ions (D) the valence electrons of a halogen ion,C,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
metallic bonds form a lattice-like structure.,(A) true (B) false,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
metals can be involved in,(A) covalent bonds (B) metallic bonds (C) ionic bonds (D) two of the above,D,"We rely on metals, such as aluminum, copper, iron, and gold. Look around the room. How many objects have metal parts? Metals are used in the tiny parts inside your computer, in the wires of anything that uses electricity, and to make the structure of a large building, such as the one shown in the Figure 3.23. "
the substances that form in a chemical reaction are completely different from the substances that start the reaction.,(A) true (B) false,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
a chemical equation is balanced when,(A) the reactants are the same as the products (B) the same atoms and molecules appear on each side of the equation (C) the same number of each type of atom appears on both sides of the arrow (D) none of the above,C,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
which of the following chemical equations is balanced?,(A) 3Fe + 3O2 → 3Fe2O3 (B) 2Fe + O2 → Fe2O3 (C) 4Fe + 2O2 → 3Fe2O3 (D) 4Fe + 3O2 → 2Fe2O3,D,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
a given chemical compound always has exactly the same ratio of elements.,(A) true (B) false,A,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
"when there is just one atom of an element in a molecule, this atom is represented by the",(A) subscript 1 (B) subscript 0 (C) absence of a subscript (D) none of the above,C,"The smallest particle of an element that still has the properties of that element is an atom. Atoms are extremely tiny. They can be observed only with an electron microscope. They are commonly represented by models, like the one Figure 2.6. An atom has a central nucleus that is positive in charge. The nucleus is surrounded by negatively charged particles called electrons. The smallest particle of a compound that still has the properties of that compound is a molecule. A molecule consists of two or more atoms. For example, a molecule of water consists of two atoms of hydrogen and one atom of oxygen. Thats why the chemical formula for water is H2 O. You can see a simple model of a water molecule in Figure 2.7. "
"in the formula for an ionic compound, the negative ion is always written first.",(A) true (B) false,B,"Ionic compounds are named for their positive and negative ions. The name of the positive ion always comes first, followed by the name of the negative ion. For example, positive sodium ions and negative chloride ions form the compound named sodium chloride. Similarly, positive calcium ions and negative chloride ions form the compound named calcium chloride. Q: What is the name of the ionic compound that is composed of positive barium ions and negative iodide ions? A: The compound is named barium iodide. "
correct rules for writing the chemical formulas of covalent compounds include which of the following?,(A) The element that is farther to the left in the periodic table is written first (B) The element that is farther to the right in the periodic table is written first (C) If both elements are in the same group of the periodic table (D) the one with the lower period number is written first (E) d two of the above,A,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
the chemical formula for the compound that consists of barium ions (ba+2) and oxide ions (o-2) is,(A) OBa (B) O2Ba2 (C) Ba2O2 (D) BaO,D,"Barium (Ba) is one of six elements in group 2 of the periodic table, which is shown in Figure 1.1. Elements in this group are called alkaline Earth metals. These metals are silver or gray in color. They are relatively soft and low in density, although not as soft and lightweight as alkali metals. "
a chemical reaction changes some substances into other substances with different chemical properties.,(A) true (B) false,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
the substances involved in a chemical reaction may be elements or compounds.,(A) true (B) false,A,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
during a chemical reaction,(A) chemical bonds break (B) matter is destroyed (C) new atoms form (D) two of the above,A,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
which of the following represents a synthesis reaction?,(A) 2H2 + O2 → 2H2O (B) 2K + 2H2O → 2KOH + H2 (C) 2NaCl → 2Na + Cl2 (D) none of the above,A,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
which type of reaction is represented by the following chemical equation? ch4 + 2o2  co2 + 2h2o,(A) combustion reaction (B) decomposition reaction (C) single replacement reaction (D) double replacement reaction,A,"A chemical reaction occurs when some substances change chemically to other substances. Chemical reactions are represented by chemical equations. Consider a simple chemical reaction, the burning of methane. In this reaction, methane (CH4 ) combines with oxygen (O2 ) in the air and produces carbon dioxide (CO2 ) and water vapor (H2 O). The reaction is represented by the following chemical equation: CH4 + 2O2  CO2 + 2H2 O This equation shows that one molecule of methane combines with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water vapor. All chemical equations must be balanced. This means that the same number of each type of atom must appear on both sides of the arrow. Q: Is the chemical equation for the burning of methane balanced? Count the atoms of each type on both sides of the arrow to find out. A: Yes, the equation is balanced. There is one carbon atom on both sides of the arrow. There are also four hydrogen atoms and four oxygen atoms on both sides of the arrow. "
factors that affect the rate of a chemical reaction include,(A) concentration of reactants (B) surface area of reactants (C) temperature of reactants (D) all of the above,D,How fast a chemical reaction occurs is called the reaction rate. Several factors affect the rate of a given chemical reaction. They include the: temperature of reactants. concentration of reactants. surface area of reactants. presence of a catalyst. 
warmer reactants react more quickly than cooler reactants.,(A) true (B) false,A,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. They are more likely to bump into one another and to collide with greater force. For example, when you fry an egg, turning up the heat causes the egg to cook faster. The same principle explains why storing food in a cold refrigerator reduces the rate at which food spoils (see Figure 8.16). Both food frying and food spoiling are chemical reactions that happen faster at higher temperatures. "
food spoils faster at higher temperatures because heat is a catalyst.,(A) true (B) false,B,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. As a result, they are more likely to bump into one another and to collide with greater force. For example, food spoils because of chemical reactions, and these reactions occur faster at higher temperatures (see the bread on the left in the Figure 1.1). This is why we store foods in the refrigerator or freezer (like the bread on the right in the Figure 1.1). The lower temperature slows the rate of spoilage. Left image: Bread after 1 month on a warm countertop. Right image: Bread after 1 month in a cold refrigerator. "
which statement is true about any catalyst?,(A) It is a reactant in a chemical reaction (B) It is used up in a chemical reaction (C) It can speed up many chemical reactions (D) all of the above,C,"Catalysts interact with reactants so the reaction can occur by an alternate pathway that has a lower activation energy. Activation energy is the energy needed to start a reaction. When activation energy is lower, more reactant particles have enough energy to react so the reaction goes faster. Many catalysts work like the one in the Figure 1.1. The catalyst brings the reactants together by temporarily bonding with them. This makes it easier and quicker for the reactants to react together. Q: In the Figure 1.1, look at the energy needed in the catalytic and non-catalytic pathways of the reaction. How does the amount of energy compare? How does this affect the reaction rate along each pathway? A: The catalytic pathway of the reaction requires far less energy. Therefore, the reaction will occur faster by this pathway because more reactants will have enough energy to react. "
warmer reactants have more energy and move faster.,(A) true (B) false,A,"When the temperature of reactants is higher, the rate of the reaction is faster. At higher temperatures, particles of reactants have more energy, so they move faster. They are more likely to bump into one another and to collide with greater force. For example, when you fry an egg, turning up the heat causes the egg to cook faster. The same principle explains why storing food in a cold refrigerator reduces the rate at which food spoils (see Figure 8.16). Both food frying and food spoiling are chemical reactions that happen faster at higher temperatures. "
all compounds consist of a fixed ratio of elements.,(A) true (B) false,A,"A compound is a unique substance that forms when two or more elements combine chemically. Compounds form as a result of chemical reactions. The elements in compounds are held together by chemical bonds. A chemical bond is a force of attraction between atoms or ions that share or transfer valence electrons. Click image to the left or use the URL below. URL:  Water is an example of a common chemical compound. As you can see in the Figure 1.1, each water molecule consists of two atoms of hydrogen and one atom of oxygen. Water always has this 2:1 ratio of hydrogen to oxygen. Like water, all compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. Q: Sometimes the same elements combine in different ratios. How can this happen if a compound always consists of the same elements in the same ratio? A: If the same elements combine in different ratios, they form different compounds. "
covalent compounds are compounds that,(A) consist only of nonmetallic elements (B) have atoms that share electrons (C) exist as individual molecules (D) all of the above,D,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
water is an example of a covalent compound.,(A) true (B) false,A,"Water (H2 O) is an example of a chemical compound. Water molecules always consist of two atoms of hydrogen and one atom of oxygen. Like water, all other chemical compounds consist of a fixed ratio of elements. It doesnt matter how much or how little of a compound there is. It always has the same composition. "
ionic compounds are compounds that,(A) consist only of metallic elements (B) have atoms that transfer electrons (C) exist as individual ions (D) all of the above,B,"Ionic compounds contain ions of metals and nonmetals held together by ionic bonds. Ionic compounds do not form molecules. Instead, many positive and negative ions bond together to form a structure called a crystal. You can see an example of a crystal in Figure 7.5. It shows the ionic compound sodium chloride. Positive sodium ions (Na+ ) alternate with negative chloride ions (Cl ). The oppositely charged ions are strongly attracted to each other. Helpful Hints Naming Ionic Compounds Ionic compounds are named for their positive and negative ions. The name of the positive "
carbon dioxide is an example of an ionic compound.,(A) true (B) false,B,"The Table 1.1 shows four examples of compounds and their chemical formulas. The first two compounds are ionic compounds, and the second two are covalent compounds. Each formula shows the ratio of ions or atoms that make up the compound. Name of Compound Type of Compound Sodium chloride ionic Calcium iodide ionic Hydrogen peroxide covalent Carbon dioxide covalent Ratio of Ions or Atoms of Each Element 1 sodium ion (Na+ ) 1 chloride ion (Cl ) 1 calcium ion (Ca2+ ) 2 io- dide ions (I ) 2 hydrogen atoms (H) 2 oxygen atoms (O) 1 carbon atom (C) 2 oxy- gen atoms (O) Chemical Formulas NaCl CaI2 H2 O2 CO2 There is a different rule for writing the chemical formula for each type of compound. Ionic compounds are compounds in which positive metal ions and negative nonmetal ions are joined by ionic bonds. In these compounds, the chemical symbol for the positive metal ion is written first, followed by the symbol for the negative nonmetal ion. Click image to the left or use the URL below. URL:  Q: The ionic compound lithium fluoride consists of a ratio of one lithium ion (Li+ ) to one fluoride ion (F ). What is the chemical formula for this compound? A: The chemical formula is LiF. Covalent compounds are compounds in which nonmetals are joined by covalent bonds. In these compounds, the element that is farther to the left in the periodic table is written first, followed by the element that is farther to the right. If both elements are in the same group of the periodic table, the one with the higher period number is written first. Click image to the left or use the URL below. URL:  Q: A molecule of the covalent compound nitrogen dioxide consists of one nitrogen atom (N) and two oxygen atoms (O). What is the chemical formula for this compound? A: The chemical formula is NO2 . "
a rainbow includes all the colors of visible light.,(A) true (B) false,A,"The only light that people can see is called visible light. It refers to a very narrow range of wavelengths in the electromagnetic spectrum that falls between infrared light and ultraviolet light. Within the visible range, we see light of different wavelengths as different colors of light, from red light, which has the longest wavelength, to violet light, which has the shortest wavelength. You can see the spectrum of colors of visible light in Figure 21.11. When all of the wavelengths are combined, as they are in sunlight, visible light appears white. You can learn more about visible light in the chapter ""Visible Light"" and at the URL below. "
visible light includes all the wavelengths of light that the human eye can detect.,(A) true (B) false,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
leaves appear green because they,(A) absorb only green light (B) reflect only green light (C) transmit only green light (D) none of the above,B,"In plants, most chloroplasts are found in the leaves. Therefore, all the raw materials needed for photosynthesis must be present in the leaves. These materials include light, water, and carbon dioxide. The shape of the leaves gives them a lot of surface area to absorb light for photosynthesis. Roots take up water from the soil. Stems carry the water from the roots to the leaves. Carbon dioxide enters the leaves through tiny openings called stomata. (The oxygen released during photosynthesis also exits the leaves through the stomata.) "
"if only blue light strikes green leaves, the leaves appear",(A) green (B) blue (C) black (D) white,C,"An opaque object is one that doesnt let light pass through it. Instead, it reflects or absorbs the light that strikes it. Many objects, such as the leaves pictured in the Figure 1.3, reflect just one or a few wavelengths of visible light and absorb the rest. The wavelengths that are reflected determine the color that an object appears to the human eye. For example, the leaves appear green because they reflect green light and absorb light of other wavelengths. A transparent or translucent material, such as window glass, transmits some or all of the light that strikes it. This means that the light passes through the material rather than being reflected by it. In this case, we see the material because of the transmitted light. Therefore, the wavelength of the transmitted light determines the color that the object appears. Look at the beautiful stained glass windows in the Figure 1.4. The different colors of glass transmit The color of light that strikes an object may also affect the color that the object appears. For example, if only blue light strikes green leaves, the blue light is absorbed and no light is reflected. Q: What color do you see if an object absorbs all of the light that strikes it? A: When all of the light is absorbed, none is reflected, so the object looks black. But black isnt a color of light. Black is the absence of light. "
primary colors of light include,(A) red (B) cyan (C) magenta (D) all of the above,A,"The human eye can distinguish only red, green, and blue light. These three colors are called the primary colors of light. All other colors of light can be created by combining the primary colors. Look at the Venn diagram 1.5. Red and green light combine to form yellow light. Red and blue light combine to form magenta light, and blue and green light combine to form cyan light. Yellow, magenta, and cyan are called the secondary colors of light. Look at the center of the diagram, where all three primary colors of light combine. The result is white light. "
primary colors of pigments include,(A) yellow (B) blue (C) green (D) none of the above,A,"Many objects have color because they contain pigments. A pigment is a substance that colors materials by reflecting light of certain wavelengths and absorbing light of other wavelengths. A very common pigment is the dark green pigment called chlorophyll, which is found in plants. Chlorophyll absorbs all but green wavelengths of visible light. Pigments are also found in many manufactured products. They are used to color paints, inks, and dyes. Just three pigments, called primary pigments, can be combined to produce all other colors. The primary colors of pigments are the same as the secondary colors of light: cyan, magenta, and yellow. Q: A color printer needs just three colors of ink to print all of the colors that we can see. Which colors are they? A: The three colors of ink in a color printer are the three primary pigment colors: cyan, magenta, and yellow. These three colors can be combined in different ratios to produce all other colors, so they are the only colors needed for full-color printing. "
the net force acting on you when you sit still in a chair is zero.,(A) true (B) false,A,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
"when two forces act on an object in opposite directions, you calculate the net force by",(A) dividing the two forces (B) subtracting the two forces (C) finding the average of the two forces (D) none of the above,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
"when two forces act on an object in the same direction, you calculate the net force by",(A) adding the two forces (B) multiplying the two forces (C) finding the larger of the two forces (D) none of the above,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
"when two forces act on the same object in opposite directions, the net force is always greater than the individual forces.",(A) true (B) false,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
"when two forces act on the same object in the same direction, the net force is always less than the individual forces.",(A) true (B) false,B,"When two forces act on an object in opposite directions, like the book on the table, the net force is equal to the difference between the two forces. In other words, one force is subtracted from the other to calculate the net force. If the opposing forces are equal in strength, the net force is zero. Thats what happens with the book on the table. The upward force minus the downward force equals zero (20 N up - 20 N down = 0 N). Because the forces on the book are balanced, the book remains on the table and doesnt move. In addition to these downward and upward forces, which generally cancel each other out, forces may push or pull an object in other directions. Look at the dogs playing tug-of-war in Figure 13.4. One dog is pulling on the rope with a force of 10 newtons to the left. The other dog is pulling on the rope with a force of 12 newtons to the right. These opposing forces are not equal in strength, so they are unbalanced. When opposing forces are unbalanced, the net force is greater than zero. The net force on the rope is 2 newtons to the right, so the rope will move to the right. "
most fuels in combustion reactions are compounds called,(A) proteins (B) ionic compounds (C) hydrocarbons (D) halogens,C,"The fuel that burns in a combustion reaction is often a substance called a hydrocarbon. A hydrocarbon is a compound that contains only carbon (C) and hydrogen (H). Fossil fuels, such as natural gas, consist of hydrocarbons. Natural gas is a fuel that is commonly used in home furnaces and gas stoves (see Figure 8.11). The main component of natural gas is the hydrocarbon called methane (CH4 ). The combustion of methane is represented by the equation: CH4 + 2O2 ! CO2 + 2H2 O "
the main component of natural gas is nitrogen.,(A) true (B) false,B,Natural gas is mostly methane. 
products of incomplete combustion include only carbon dioxide and water.,(A) true (B) false,B,"A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). For example, in the Figure usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO2 ) and water vapor (H2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is: Fuel + O2  CO2 + H2 O The burning of charcoal is a combustion reaction. "
some compound machines consist of thousands of simple machines.,(A) true (B) false,A,"A compound machine is a machine that consists of more than one simple machine. Some compound machines consist of just two simple machines. You can read below about two examplesthe wheelbarrow and corkscrew. Other compound machines, such as bicycles, consist of many simple machines. Big compound machines such as cars may consist of hundreds or even thousands of simple machines. "
"when you use a wheelbarrow, you apply effort to the",(A) wheel (B) axle (C) lever (D) two of the above,D,"Look at the wheelbarrow in the Figure 1.1. It is used to carry heavy objects. It consists of two simple machines: a lever and a wheel and axle. Effort is applied to the lever by picking up the handles of the wheelbarrow. The lever, in turn, applies upward force to the load. The force is increased by the lever, making the load easier to lift. Effort is applied to the wheel of the wheelbarrow by pushing it over the ground. The rolling wheel turns the axle and increases the force, making it easier to push the load. "
a corkscrew consists of,(A) two levers (B) a screw (C) a wheel and axle (D) two of the above,D,"The corkscrew in the Figure 1.2 is also a compound machine. It is used to pierce a cork and pull it out of the neck of a bottle. It consists of a screw and two levers. Turning the handle on top twists the screw down into the center of the cork. Then, pushing down on the two levers causes the screw to pull upward, bringing the cork with it. The levers increase the force and change its direction. "
all machines must overcome friction.,(A) true (B) false,A,"Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of many simple machines, friction can become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts of a machine so they slide over each other more easily. This is how friction is reduced in a car engine. "
no machine is 100 percent efficient.,(A) true (B) false,A,"You read above that machines do not increase the work done on an object. In other words, you cant get more work out of a machine than you put into it. In fact, machines always do less work on the object than the user does on the machine. Thats because all machines must use some of the work put into them to overcome friction. How much work? It depends on the efficiency of the machine. Efficiency is the percent of input work that becomes output work. It is a measure of how well a machine reduces friction. "
which of the following is a compound?,(A) air (B) oxygen (C) carbon dioxide (D) two of the above,C,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
a compound always has the same elements in the same proportions.,(A) true (B) false,A,"There are millions of different substances in the world. Thats because elements can combine in many different ways to form new substances. In fact, most elements are found in compounds. A compound is a unique substance that forms when two or more elements combine chemically. An example is water, which forms when hydrogen and oxygen combine chemically. A compound always has the same components in the same proportions. It also has the same composition throughout. You can learn more about compounds and how they form by watching this video: MEDIA Click image to the left or use the URL below. URL: "
the properties of compounds are the same as the properties of the elements that form them.,(A) true (B) false,B,"A compound is a unique substance that forms when two or more elements combine chemically. For example, the compound carbon dioxide forms when one atom of carbon (grey in the model above) combines with two atoms of oxygen (red in the model). Another example of a compound is water. It forms when two hydrogen atoms combine with one oxygen atom. Click image to the left or use the URL below. URL:  Q: How could a water molecule be represented? A: It could be represented by a model like the one for carbon dioxide in the opening image. You can see a sample Figure 1.1. A model of water. Two things are true of all compounds: A compound always has the same elements in the same proportions. For example, carbon dioxide always has two atoms of oxygen for each atom of carbon, and water always has two atoms of hydrogen for each atom of oxygen. A compound always has the same composition throughout. For example, all the carbon dioxide in the atmosphere and all the water in the ocean have these same proportions of elements. Q: How do you think the properties of compounds compare with the properties of the elements that form them? A: You might expect the properties of a compound to be similar to the properties of the elements that make up the compound. But you would be wrong. "
which of the following substances is a compound that forms ionic crystals?,(A) water (B) sodium chloride (C) carbon dioxide (D) none of the above,B,"Many compounds form molecules, but ionic compounds form crystals instead. A crystal consists of many alternating positive and negative ions bonded together in a matrix. Look at the crystal of sodium chloride (NaCl) in the Figure bonds. Sodium chloride crystals are cubic in shape. Other ionic compounds may have crystals with different shapes. "
which of the following gases is a compound that forms molecules?,(A) air (B) carbon dioxide (C) oxygen (D) nitrogen,B,"A molecule is any combination of two or more atoms. The oxygen in the air we breathe is two oxygen atoms connected by a chemical bond to form O2 , or molecular oxygen. A carbon dioxide molecule is a combination of one carbon atom and two oxygen atoms, CO2 . Because carbon dioxide includes two different elements, it is a compound as well as a molecule. A compound is any combination of two or more different elements. A compound has different properties from the elements that it contains. Elements and combinations of elements (compounds) make up all the many types of matter in the Universe. A chemical reaction is a process that breaks or forms the bonds between atoms of molecules and compounds. For example, two hydrogens and one oxygen bind together to form water, H2 O. The molecules that come together to start a chemical reaction are the reactants. So hydrogen and oxygen are the reactants. The product is the end result of a reaction. In this example, water is the product. Atoms also come together to form compounds much larger than water. It is some of these large compounds that come together to form the basis of the cell. So essentially, your cells are made out of compounds, which are made out of atoms. "
a molecule consists of two or more atoms bonded together.,(A) true (B) false,A,"A molecule is any combination of two or more atoms. The oxygen in the air we breathe is two oxygen atoms connected by a chemical bond to form O2 , or molecular oxygen. A carbon dioxide molecule is a combination of one carbon atom and two oxygen atoms, CO2 . Because carbon dioxide includes two different elements, it is a compound as well as a molecule. A compound is any combination of two or more different elements. A compound has different properties from the elements that it contains. Elements and combinations of elements (compounds) make up all the many types of matter in the Universe. A chemical reaction is a process that breaks or forms the bonds between atoms of molecules and compounds. For example, two hydrogens and one oxygen bind together to form water, H2 O. The molecules that come together to start a chemical reaction are the reactants. So hydrogen and oxygen are the reactants. The product is the end result of a reaction. In this example, water is the product. Atoms also come together to form compounds much larger than water. It is some of these large compounds that come together to form the basis of the cell. So essentially, your cells are made out of compounds, which are made out of atoms. "
which statement about energy and chemical reactions is true?,(A) All chemical reactions involve energy (B) Breaking bonds in reactants requires energy (C) Forming bonds in products releases energy (D) all of the above,D,"Whether a chemical reaction absorbs or releases energy, there is no overall change in the amount of energy during the reaction. Thats because energy cannot be created or destroyed. This is the law of conservation of energy. Energy may change form during a chemical reactionfor example, from chemical energy to heat energy when gas burns in a furnacebut the same amount of energy remains after the reaction as before. This is true of all chemical reactions. Q: If energy cant be destroyed during a chemical reaction, what happens to the energy that is absorbed in an endothermic reaction? A: The energy is stored in the bonds of the products as chemical energy. In an endothermic reaction, the products have more stored chemical energy than the reactants. This is represented by the graph on the left in the Figure 1.1. In an exothermic reaction, the opposite is true. The products have less stored chemical energy than the reactants. You can see this in the graph on the right in the Figure 1.1. Note: H represents the change in en- ergy. Q: What happens to the excess energy in the reactants of an exothermic reaction? A: The excess energy is generally released to the surroundings when the reaction occurs. In a home heating system, for example, the energy that is released during combustion in the furnace is used to heat the home. "
energy cannot be created or destroyed in chemical reactions.,(A) true (B) false,A,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
energy cannot change form during chemical reactions.,(A) true (B) false,B,Energy changes form when something happens. But the total amount of energy always stays the same. The Law of Conservation of Energy says that energy cannot be created or destroyed. Scientists observed that energy could change from one form to another. They also observed that the overall amount of energy did not change. 
"in an endothermic reaction, products have less chemical energy than reactants.",(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called endothermic reactions, less energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of exothermic reactions. In an exothermic reaction, it takes less energy to break bonds in the reactants than is released when new bonds form in the products. "
when natural gas burns in a furnace,(A) energy is released in the form of heat and light (B) it takes more energy to break bonds in reactants than to form bonds in products (C) the natural gas creates energy as it burns (D) two of the above,A,"The fuel that burns in a combustion reaction contains compounds called hydrocarbons. Hydrocarbons are compounds that contain only carbon (C) and hydrogen (H). The charcoal pictured in the Figure 1.1 consists of hydrocarbons. So do fossil fuels such as natural gas. Natural gas is a fuel that is commonly used in home furnaces and gas stoves. The main component of natural gas is the hydrocarbon called methane (CH4 ). You can see a methane flame in the Figure 1.2. The combustion of methane is represented by the equation: CH4 + 2O2  CO2 + 2H2 O The combustion of methane gas heats a pot on a stove. Q: Sometimes the flame on a gas stove isnt just blue but has some yellow or orange in it. Why might this occur? A: If the flame isnt just blue, the methane isnt getting enough oxygen to burn completely, leaving some of the carbon unburned. The flame will also not be as hot as a completely blue flame for the same reason. "
the letter e in einsteins equation e = mc2 stands for,(A) electricity (B) electrons (C) energy (D) efficiency,C,"Einsteins equation is possibly the best-known equation of all time. Theres reason for that. The equation is incredibly important. It changed how scientists view energy and matter, which are two of the most basic concepts in all of science. The equation shows that energy and matter are two forms of the same thing. This new idea turned science upside down when Einstein introduced it in the early 1900s. Amazingly, the idea has withstood the test of time as more and more evidence has been gathered to support it. You can listen to an explanation of Einsteins equation at URL: https://youtu.be/hW7DW9NIO9M Q: What do the letters in Einsteins equation stand for? A: E stands for energy, m stands for mass, and c stands for the speed of light. The speed of light is 300,000 kilometers (186,000 miles) per second, so c2 is a very big number. Therefore, the amount of energy in even a small mass of matter is tremendous. Suppose, for example, that you have 1 gram of matter. Thats about the mass of a paperclip. Multiplying this mass by c2 would yield enough energy to power 3,600 homes for a year! "
the letter c in the equation in question 1 represents a constant.,(A) true (B) false,A,"In Einsteins equation, the variable E stands for energy and the variable m stands for mass. The c in the equation is a constant. It stands for the speed of light. The speed of light is 300,000 kilometers (186,000 miles) per second, so c2 is a very big number, no matter what units are used to measure it. Einsteins equation means that the energy in a given amount of matter is equal to its mass times the square of the speed of light. Thats a huge amount of energy from even a tiny amount of mass. Suppose, for example, that you have 1 gram of matter. Thats about the mass of a paperclip. Multiplying that mass by the square of the speed of light yields enough energy to power 3,600 homes for a year! "
"the speed of light is 300,000 km per hour.",(A) true (B) false,B,"In space, light travels at about 300,000,000 meters per second (670,000,000 miles per hour). How fast is that? A beam of light could travel from New York to Los Angeles and back again nearly 40 times in just one second. Even at that amazing rate, objects in space are so far away that it takes a lot of time for their light to reach us. Even light from the nearest star, our Sun, takes about 8 minutes to reach Earth. "
einsteins equation has recently been disproven by real-world evidence.,(A) true (B) false,B,"After Einstein proposed his theory, evidence was discovered to support it. For example, scientists shone laser light through two slits in a barrier made of a material that blocked light. You can see the setup of this type of experiment in the Figure 1.2. Using a special camera that was very sensitive to light, they took photos of the light that passed through the slits. The photos revealed tiny pinpoints of light passing through the double slits. This seemed to show that light consists of particles. However, if the camera was exposed to the light for a long time, the pinpoints accumulated in bands that resembled interfering waves. Therefore, the experiment showed that light seems to consist of particles that act like waves. "
the amount of energy in a tiny amount of mass is very large.,(A) true (B) false,A,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
einsteins equation shows that mass and energy are not conserved in nuclear reactions.,(A) true (B) false,B,"Einsteins equation helps scientists understand what happens in nuclear reactions and why they produce so much energy. When the nucleus of a radioisotope undergoes fission or fusion in a nuclear reaction, it loses a tiny amount of mass. What happens to the lost mass? It isnt really lost at all. It is converted to energy. How much energy? E = mc2 . The change in mass is tiny, but it results in a great deal of energy. Q: In a nuclear reaction, mass decreases and energy increases. What about the laws of conservation of mass and conservation of energy? Are mass and energy not conserved in nuclear reactions? Do we need to throw out these laws when it comes to nuclear reactions? A: No, the laws still apply. However, its more correct to say that the sum of mass and energy is always conserved in a nuclear reaction. Mass changes to energy, but the total amount of mass and energy combined remains the same. "
chemical reactions are represented by chemical formulas.,(A) true (B) false,B,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
which choice correctly represents the reaction in which methane burns?,(A) CH4 + 2O2 → CO2 + 2H2O (B) 2CH4 + 2O2 → CO2 + 2H2O (C) CH4 + O2 → CO2 + H2O (D) none of the above,A,"A chemical reaction occurs when some substances change chemically to other substances. Chemical reactions are represented by chemical equations. Consider a simple chemical reaction, the burning of methane. In this reaction, methane (CH4 ) combines with oxygen (O2 ) in the air and produces carbon dioxide (CO2 ) and water vapor (H2 O). The reaction is represented by the following chemical equation: CH4 + 2O2  CO2 + 2H2 O This equation shows that one molecule of methane combines with two molecules of oxygen to produce one molecule of carbon dioxide and two molecules of water vapor. All chemical equations must be balanced. This means that the same number of each type of atom must appear on both sides of the arrow. Q: Is the chemical equation for the burning of methane balanced? Count the atoms of each type on both sides of the arrow to find out. A: Yes, the equation is balanced. There is one carbon atom on both sides of the arrow. There are also four hydrogen atoms and four oxygen atoms on both sides of the arrow. "
the equation h2 + o2  h2o is balanced.,(A) true (B) false,B,"Some chemical equations are more challenging to write. Consider the reaction in which hydrogen (H2 ) and oxygen (O2 ) combine to form water (H2 O). Hydrogen and oxygen are the reactants, and water is the product. To write a chemical equation for this reaction, you would start by writing symbols for the reactants and products: Equation 1: H2 + O2 ! H2 O Like equations in math, equations in chemistry must balance. There must be the same number of each type of atom in the products as there is in the reactants. In equation 1, count the number of hydrogen and oxygen atoms on each side of the arrow. There are two hydrogen atoms in both reactants and products. There are two oxygen atoms in the reactants but only one in the product. Therefore, equation 1 is not balanced. "
which equation shows that mass is conserved in the chemical reaction?,(A) 2Al + 2O2 → 2Al2O3 (B) 2Al + O2 → Al2O3 (C) 4Al + 3O2 → 2Al2O3 (D) none of the above,C,"All chemical equations, like equations in math, must balance. This means that there must be the same number of each type of atom on both sides of the arrow. Thats because matter is always conserved in a chemical reaction. This is the law of conservation of mass. Look at the equation above for the reaction between carbon and oxygen in the formation of carbon dioxide. Count the number of atoms of each type. Are the numbers the same on both sides of the arrow? The answer is yes, so the equation is balanced. "
heat is the transfer of thermal energy.,(A) true (B) false,A,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
when particles of matter in one part of a fluid gain thermal energy they,(A) move more quickly (B) have more collisions (C) spread farther apart (D) all of the above,D,"The Figure 1.1 shows how convection occurs, using hot water in a pot as an example. When particles in one area of a fluid (in this case, the water at the bottom of the pot) gain thermal energy, they move more quickly, have more collisions, and spread farther apart. This decreases the density of the particles, so they rise up through the fluid. As they rise, they transfer their thermal energy to other particles of the fluid and cool off in the process. With less energy, the particles move more slowly, have fewer collisions, and move closer together. This increases their density, so they sink back down through the fluid. When they reach the bottom of the fluid, the cycle repeats. The result is a loop of moving particles called a convection current. "
"when particles are more spread out, they have higher density.",(A) true (B) false,B,"Density is mass per unit volume. Density is a measure of how closely molecules are packed together. The closer together they are, the greater the density. Since air is a gas, the molecules can pack tightly or spread out. The density of air varies from place to place. Air density depends on several factors. One is temperature. Like other materials, warm air is less dense than cool air. Since warmer molecules have more energy, they are more active. The molecules bounce off each other and spread apart. Another factor that affects the density of air is altitude. "
higher density particles sink downward through a fluid.,(A) true (B) false,A,"Two factors influence the pressure of fluids. They are the depth of the fluid and its density. A fluid exerts more pressure at greater depths. Deeper in a fluid, all of the fluid above it results in more weight pressing down. This causes greater pressure the deeper you go. Denser fluids such as water exert more pressure than less dense fluids such as air. The particles of denser fluids are closer together, so there are more collisions of particles in a given area. The difference in density of water and air is illustrated in the Figure 1.3. "
convection currents transfer thermal energy through earths,(A) oceans (B) atmosphere (C) molten rock (D) all of the above,D,"Convection currents transfer thermal energy through many fluids, not just hot water in a pot. For example, convection currents transfer thermal energy through molten rock below Earths surface, through water in the oceans, and through air in the atmosphere. Convection currents in the atmosphere create winds. You can see one way this happens in the Figure 1.2. The land heats up and cools off faster than the water because it has lower specific heat. Therefore, the land gets warmer during the day and cooler at night than the water does. During the day, warm air rises above the land and cool air from the water moves in to take its place. During the night, the opposite happens. Warm air rises above the water and cool air from the land moves out to take its place. Q: During the day, in which direction is thermal energy of the air transferred? In which direction is it transferred during the night? A: During the day, thermal energy is transferred from the air over the land to the air over the water. During the night, thermal energy is transferred in the opposite direction. "
work as defined in physics always involves,(A) force (B) motion (C) energy (D) all of the above,D,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isnt moving anything, so she isnt doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure 1.1 illustrates this point. Q: If the box the man is carrying is very heavy, does he do any work as he walks across the room with it? A: Regardless of the weight of the box, the man does no work on it as he holds it while walking across the room. However, he does more work when he first lifts a heavier box to chest height. "
most cooling systems get energy from electricity.,(A) true (B) false,A,"A refrigerator is an example of a cooling system. Another example is an air conditioner. The purpose of any cooling system is to transfer thermal energy in order to keep things cool. A refrigerator, for example, transfers thermal energy from the cool air inside the refrigerator to the warm air in the kitchen. If youve ever noticed how warm the back of a running refrigerator gets, then you know that it releases a lot of thermal energy into the room. Q: Thermal energy always moves from a warmer area to a cooler area. How can thermal energy move from the cooler air inside a refrigerator to the warmer air in a room? A: The answer is work. "
"in a cooling system, the refrigerant",(A) has a high boiling point (B) absorbs thermal energy from air inside the refrigerator (C) pumps cool air into the refrigerator (D) two of the above,B,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
the refrigerant changes between solid and liquid states as it passes through the refrigerator.,(A) true (B) false,B,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
as a liquid the refrigerant transfers thermal energy to the outside air.,(A) true (B) false,B,"The key to how a refrigerator or other cooling system works is the refrigerant. A refrigerant is a substance such as FreonTM that has a low boiling point and changes between liquid and gaseous states as it passes through the refrigerator. As a liquid, the refrigerant absorbs thermal energy from the cool air inside the refrigerator and changes to a gas. As a gas, it transfers thermal energy to the warm air outside the refrigerator and changes back to a liquid. Work is done by a refrigerator to move the refrigerant through the different components of the refrigerator. "
"in covalent bonds, the atoms that form bonds",(A) may be metals or nonmetals (B) transfer electrons (C) may both be the same element (D) all of the above,C,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
electrons in covalent bonds are attracted to the nucleus of just one atom.,(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
a covalent bond always includes a pair of electrons.,(A) true (B) false,A,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
elements that form diatomic molecules include,(A) oxygen (B) hydrogen (C) chlorine (D) all of the above,D,"Covalent bonds between atoms of different elements form covalent compounds. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohydrates. These are compounds in living things. Helpful Hints Naming Covalent Compounds Follow these rules in naming simple covalent compounds: The element closer to the left of the periodic table is named first. The second element gets the suffix ide. Prefixes such as di- (2) and tri- (3) show the number of each atom in the compound. These are written with subscripts in the chemical formula. Example: The gas that consists of one carbon atom and two oxygen atoms is named carbon dioxide. Its chemical formula is CO2 . You Try It! Problem: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? What is its chemical formula? "
the formation of one or more covalent bonds always results in a covalent compound.,(A) true (B) false,B,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
which of the following is a covalent compound?,(A) H2O (B) NaCl (C) O2 (D) two of the above,A,"Compounds that form from two or more nonmetallic elements, such as carbon and hydrogen, are called covalent compounds. In a covalent compound, atoms of the different elements are held together in molecules by covalent bonds. These are chemical bonds in which atoms share valence electrons. The force of attraction between the shared electrons and the positive nuclei of both atoms holds the atoms together in the molecule. A molecule is the smallest particle of a covalent compound that still has the properties of the compound. The largest, most complex covalent molecules have thousands of atoms. Examples include proteins and carbohy- drates, which are compounds in living things. The smallest, simplest covalent compounds have molecules with just two atoms. An example is hydrogen chloride (HCl). It consists of one hydrogen atom and one chlorine atom, as you can see in the Figure 1.1. "
forms of crystalline carbon include,(A) coal (B) graphite (C) charcoal (D) two of the above,B,"Graphite is one of three forms of crystalline, or crystal-forming, carbon. Carbon also exists in an amorphous, or shapeless, form in substances such as coal and charcoal. Different forms of the same element are called allotropes. Besides graphite, the other allotropes of crystalline carbon are diamond and fullerenes. All three forms exist as crystals rather than molecules. In a crystal, many atoms are bonded together in a repeating pattern that may contains thousands of atoms. The arrangement of atoms in the crystal differs for each form of carbon and explains why the different forms have different properties. Click image to the left or use the URL below. URL:  Q: How do you think the properties of diamond might differ from the properties of graphite? A: Diamond is clear whereas graphite is black. Diamond is also very hard, so it doesnt break easily. Graphite, in contrast, is soft and breaks very easily. "
the form of carbon in question 6 has been found in meteorites.,(A) true (B) false,A,Scientists study meteorites to learn about Earths interior. Meteorites formed in the early solar system. These objects represent early solar system materials. Some meteorites are made of iron and nickel. They are thought to be very similar to Earths core (Figure 6.2). An iron meteorite is the closest thing to a sample of the core that scientists can hold in their hands! 
diamonds are used for,(A) lubricants (B) jewelry (C) blades (D) two of the above,D,"Diamonds have many valuable properties. Diamonds are extremely hard and are used for industrial purposes. The most valuable diamonds are large, well-shaped and sparkly. Turquoise is another mineral that is used in jewelry because of its striking greenish-blue color. Many minerals have interesting appearances. Specific terms are used to describe the appearance of minerals. "
the form of crystalline carbon in which each carbon atom is covalently bonded to three other carbon atoms is,(A) diamond (B) graphite (C) charcoal (D) coal,B,"Graphite is one of three forms of crystalline, or crystal-forming, carbon. Carbon also exists in an amorphous, or shapeless, form in substances such as coal and charcoal. Different forms of the same element are called allotropes. Besides graphite, the other allotropes of crystalline carbon are diamond and fullerenes. All three forms exist as crystals rather than molecules. In a crystal, many atoms are bonded together in a repeating pattern that may contains thousands of atoms. The arrangement of atoms in the crystal differs for each form of carbon and explains why the different forms have different properties. Click image to the left or use the URL below. URL:  Q: How do you think the properties of diamond might differ from the properties of graphite? A: Diamond is clear whereas graphite is black. Diamond is also very hard, so it doesnt break easily. Graphite, in contrast, is soft and breaks very easily. "
fullerenes are used to make soccer balls.,(A) true (B) false,B,"A fullerene (also called a Bucky ball) is a form of carbon in which carbon atoms are arranged in a hollow sphere resembling a soccer ball (see Figure 1.4). Each sphere contains 60 carbon atoms, and each carbon atom is bonded to three others by single covalent bonds. The bonds are relatively weak, so fullerenes can dissolve and form solutions. Fullerenes were first discovered in 1985 and have been found in soot and meteorites. Possible commercial uses of fullerenes are under investigation. Fullerene Crystal "
scientists now reject most of daltons atomic theory.,(A) true (B) false,B,"A number of theories in science were first proposed many decades or even centuries ago, but they have withstood the test of time. An example of a physical science theory that has mainly withstood the test of time is Daltons atomic theory. John Dalton was a British chemist who lived in the late 1700s and early 1800s. Around 1800, he published his atomic theory, which is one of the most important theories in science. According to Daltons atomic theory, all substances consist of tiny particles called atoms. Furthermore, all the atoms of a given element are identical, whereas the atoms of different elements are always different. These parts of Daltons atomic theory are still accepted today, although some other details of his theory have since been disproven. Dalton based his theory on many pieces of evidence. For example, he studied many substances called compounds. These are substances that consist of two or more different elements. Dalton determined that a given compound always consists of the same elements in exactly the same proportions, no matter how small the sample of the compound. This idea is illustrated for the compound water in the Figure 1.1. Dalton concluded from this evidence that elements must be made up of tiny particles in order to always combine in the same specific proportions in any given compound. Water is a compound that consists of the elements hydrogen (H) and oxygen (O). Like other compounds, the smallest particles of water are called molecules. Each molecule of water (H2 O) contains two atoms of hydrogen and one atom of oxygen. Q: Dalton thought that atoms are the smallest particles of matter. Scientists now know that atoms are composed of even smaller particles. Does this mean that the rest of Daltons atomic theory should be thrown out? A: The discovery of particles smaller than atoms doesnt mean that we should scrap the entire theory. Atoms are still known to be the smallest particles of elements that have the properties of the elements. Also, it is atomsnot particles of atomsthat combine in fixed proportions in compounds. Instead of throwing out Daltons theory, scientists have refined and expanded on it. There are many other important physical science theories. Here are three more examples: Einsteins theory of gravity Kinetic theory of matter Wave-particle theory of light "
dalton based his ideas about atoms on his own scientific research.,(A) true (B) false,A,"Around 1800, a British chemist named John Dalton revived Democrituss early ideas about the atom. Dalton is pictured in Figure 5.8. He made a living by teaching and just did research in his spare time. Nonetheless, from his research results, he developed one of the most important theories in science. "
dalton investigated,(A) pressure of gases (B) ratios of elements in compounds (C) protons and other subatomic particles (D) two of the above,D,"Dalton did many experiments that provided evidence for atoms. For example, he studied the pressure of gases. He concluded that gases must consist of tiny particles in constant motion. Dalton also researched the properties of compounds. He showed that a compound always consists of the same elements in the same ratio. On the other hand, different compounds always consist of different elements or ratios. This can happen, Dalton reasoned, only if elements are made of tiny particles that can combine in an endless variety of ways. From his research, Dalton developed a theory of the atom. You can learn more about Dalton and his research by watching the video at this URL:  (9:03). MEDIA Click image to the left or use the URL below. URL: "
according to daltons atomic theory,(A) only compounds are made of atoms (B) no two atoms are exactly alike (C) atoms cannot be created or destroyed (D) all of the above,C,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
dalton thought that atoms consist of smaller particles of matter.,(A) true (B) false,B,"Dalton incorrectly thought that atoms are tiny solid particles of matter. He used solid wooden balls to model them. The sketch in the Figure 5.9 shows how Daltons model atoms looked. He made holes in the balls so they could be joined together with hooks. In this way, the balls could be used to model compounds. When later scientists discovered subatomic particles (particles smaller than the atom itself), they realized that Daltons models were too simple. They didnt show that atoms consist of even smaller particles. Models including these smaller particles were later developed. "
daltons atomic theory was quickly accepted by most other scientists.,(A) true (B) false,A,"From his research, Dalton developed a theory about atoms. Daltons atomic theory consists of three basic ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles, created, or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds, and a given compound always consists of the same kinds of atoms in the same proportions. Daltons atomic theory was accepted by many scientists almost immediately. Most of it is still accepted today. However, scientists now know that atoms are not the smallest particles of matter. Atoms consist of several types of smaller particles, including protons, neutrons, and electrons. "
dalton thought that a given compound always consists of the same kinds of atoms in the same proportions.,(A) true (B) false,A,The atomic theory Dalton developed consists of three ideas: All substances are made of atoms. Atoms are the smallest particles of matter. They cannot be divided into smaller particles. They also cannot be created or destroyed. All atoms of the same element are alike and have the same mass. Atoms of different elements are different and have different masses. Atoms join together to form compounds. A given compound always consists of the same kinds of atoms in the same ratio. Daltons theory was soon widely accepted. Most of it is still accepted today. The only part that is no longer accepted is his idea that atoms are the smallest particles. Scientists now know that atoms consist of even smaller particles. 
there is a low level of natural radiation in the environment.,(A) true (B) false,A,"A low level of radiation occurs naturally in the environment. This is called background radiation. One source of background radiation is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. "
sources of background radiation include,(A) cosmic rays from space (B) atomic bomb testing (C) nuclear power plants (D) all of the above,A,"A low level of radiation occurs naturally in the environment. This is called background radiation. One source of background radiation is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. "
background radiation is generally considered harmful to living things.,(A) true (B) false,B,"A low level of radiation occurs naturally in the environment. This is called background radiation. It comes from various sources. One source is rocks, which may contain small amounts of radioactive elements such as uranium. Another source is cosmic rays. These are charged particles that arrive on Earth from outer space. Background radiation is generally considered to be safe for living things. A source of radiation that may be more dangerous is radon. Radon is a radioactive gas that forms in rocks underground. It can seep into basements and get trapped inside buildings. Then it may build up and become harmful to people who breathe it. Other sources of radiation are described in the interactive animation at this URL: http://w "
radiation can cause damage by,(A) knocking electrons out of atoms (B) changing atoms to ions (C) breaking bonds in DNA (D) all of the above,D,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
only living things can be harmed by radiation.,(A) true (B) false,B,"You may have seen a sign like the one in Figure 11.3. It warns people that there is radiation in the area. Exposure to radiation can be very dangerous. Radiation damages living things by knocking electrons out of atoms and changing them to ions. Radiation also breaks bonds in DNA and other biochemical compounds. A single large exposure to radiation can burn the skin and cause radiation sickness. Symptoms of this illness include extreme fatigue, destruction of blood cells, and loss of hair. Long-term exposure to lower levels of radiation can cause cancer. For example, radon in buildings can cause lung cancer. Marie Curie died of cancer, most likely because of exposure to radiation in her research. To learn more about the harmful health effects of radiation, go to this URL:  . Nonliving things can also be damaged by radiation. For example, high levels of radiation can remove electrons from metals. This may weaken metals in nuclear power plants and space vehicles, both of which are exposed to very high levels of radiation. "
which general equation represents a decomposition reaction?,(A) A + B → AB (B) AB → A + B (C) AB + C → AC + B (D) AC → A + B,B,"A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation: AB  A + B In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the decomposition of hydrogen peroxide (H2 O2 ) to water (H2 O) and oxygen (O2 )? A: The equation for this decomposition reaction is: 2 H2 O2  2 H2 O + O2 "
products of decomposition reactions are always individual elements.,(A) true (B) false,B,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
examples of decomposition reactions include,(A) 2H2O2 → 2H2O + O2 (B) NH3 + H2O → NH4OH (C) 2NaCl → 2Na + Cl2 (D) two of the above,D,"A decomposition reaction is the reverse of a synthesis reaction. In a decomposition reaction, one reactant breaks down into two or more products. This can be represented by the general equation: AB ! A + B Two examples of decomposition reactions are described below. You can see other examples at this URL: http://w "
the reaction 2al2o3  4al + 3o2 is a decomposition reaction.,(A) true (B) false,A,"A decomposition reaction occurs when one reactant breaks down into two or more products. It can be represented by the general equation: AB  A + B In this equation, AB represents the reactant that begins the reaction, and A and B represent the products of the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the decomposition of hydrogen peroxide (H2 O2 ) to water (H2 O) and oxygen (O2 )? A: The equation for this decomposition reaction is: 2 H2 O2  2 H2 O + O2 "
"according to democritus, atoms are",(A) too small to see (B) indestructible (C) unable to be subdivided (D) all of the above,D,"Democritus idea of the atom has been called the best guess in antiquity. Thats because it was correct in many ways, yet it was based on pure speculation. It really was just a guess. Heres what Democritus thought about the atom: How many times could you cut this piece of cheese in half? How small would the smallest pieces be? All matter consists of atoms, which cannot be further subdivided into smaller particles. Atoms are extremely smalltoo small to see. Atoms are solid particles that are indestructible. Atoms are separated from one another by emptiness, or void. Q: How are Democrituss ideas about atoms similar to modern ideas about atoms? A: Modern ideas agree that all matter is made up of extremely small building blocks called atoms. Q: How are Democrituss ideas different from modern ideas? A: Although atoms are extremely small, it is now possible to see them with very powerful microscopes. Atoms also arent the solid, uncuttable particles Democritus thought. Instead, they consist of several kinds of smaller, simpler particles as well as a lot of empty space. In addition, atoms arent really indestructible because they can be changed to other forms of matter or energy. "
democritus thought that atoms are motionless.,(A) true (B) false,B,"Did you ever notice dust motes moving in still air where a beam of sunlight passes through it? You can see an example in the forest scene in the Figure 1.2. This sort of observation gave Democritus the idea that atoms are in constant, random motion. If this were true, Democritus thought, then atoms must always be bumping into each other. When they do, he surmised, they either bounce apart or stick together to form clumps of atoms. Eventually, the clumps could grow big enough to be visible matter. Q: Which modern theory of matter is similar to Democritus ideas about the motion of atoms? A: The modern kinetic theory of matter is remarkably similar to Democritus ideas about the motion of atoms. According to this theory, atoms of matter are in constant random motion. This motion is greater in gases than in liquids, and it is greater in liquids than in solids. But even in solids, atoms are constantly vibrating in place. "
democritus thought that atoms are separated from each other by empty space.,(A) true (B) false,A,"Democritus thought that different kinds of matter vary because of the size, shape, and arrangement of their atoms. For example, he suggested that sweet substances are made of smooth atoms and bitter substances are made of sharp atoms. He speculated that atoms of liquids are slippery, which allows them to slide over each other and liquids to flow. Atoms of solids, in contrast, stick together, so they cannot move apart. Differences in the weight of matter, he argued, could be explained by the closeness of atoms. Atoms of lighter matter, he thought, were more spread out and separated by more empty space. Q: Democritus thought that different kinds of atoms make up different types of matter. How is this similar to modern ideas about atoms? A: The modern view is that atoms of different elements differ in their numbers of protons and electrons and this gives them different physical and chemical properties. Dust motes dance in a beam of sunlight. "
what happened to democritus ideas about atoms?,(A) They were ridiculed by Aristotle (B) They were widely accepted in his own lifetime (C) They were almost forgotten for more than 2000 years (D) two of the above,D,"Democritus was an important philosopher, but he was less influential than another Greek philosopher named Aristo- tle, who lived about 100 years after Democritus. Aristotle rejected Democritus idea of the atom. In fact, Aristotle thought the idea was ridiculous. Unfortunately, Aristotles opinion was accepted for more than 2000 years, and Democritus idea was more or less forgotten. However, the idea of the atom was revived around 1800 by the English scientist John Dalton. Dalton developed an entire theory about the atom, much of which is still accepted today. He based his theory on experimental evidence, not on lucky guesses. "
democritus ideas were based on experimental evidence.,(A) true (B) false,B,"Democritus was an important philosopher, but he was less influential than another Greek philosopher named Aristo- tle, who lived about 100 years after Democritus. Aristotle rejected Democritus idea of the atom. In fact, Aristotle thought the idea was ridiculous. Unfortunately, Aristotles opinion was accepted for more than 2000 years, and Democritus idea was more or less forgotten. However, the idea of the atom was revived around 1800 by the English scientist John Dalton. Dalton developed an entire theory about the atom, much of which is still accepted today. He based his theory on experimental evidence, not on lucky guesses. "
the central tendency of a sample can be represented by the,(A) mean (B) median (C) mode (D) any of the above,D,"The central tendency of a sample can be represented by the mean, median, or mode. The mean is the average value. It is calculated by adding the individual measurements and dividing the sum by the total number of measurements. The median is the middle value. To find the median, rank all the measurements from smallest to largest and then find the measurement that is in the middle. The mode is the most common value. It is the value that occurs most often. Q: A sample of five children have the following heights: 60 cm, 58 cm, 54 cm, 62 cm, and 58 cm. What are the mean, median, and mode of this sample? A: The mean is (60 cm + 58 cm + 54 cm + 62 cm + 58 cm)  5 = 58 cm. The median and mode are both 58 cm as well. The mean, median, and mode are not always the same, as they are for this sample. In fact, sometimes these three statistics are very different from one another for the same sample. "
the mean and median of the same set of values are always the same.,(A) true (B) false,B,"The central tendency of a sample can be represented by the mean, median, or mode. The mean is the average value. It is calculated by adding the individual measurements and dividing the sum by the total number of measurements. The median is the middle value. To find the median, rank all the measurements from smallest to largest and then find the measurement that is in the middle. The mode is the most common value. It is the value that occurs most often. Q: A sample of five children have the following heights: 60 cm, 58 cm, 54 cm, 62 cm, and 58 cm. What are the mean, median, and mode of this sample? A: The mean is (60 cm + 58 cm + 54 cm + 62 cm + 58 cm)  5 = 58 cm. The median and mode are both 58 cm as well. The mean, median, and mode are not always the same, as they are for this sample. In fact, sometimes these three statistics are very different from one another for the same sample. "
the average of a set of values is also called the mode.,(A) true (B) false,B,"The central tendency of a sample can be represented by the mean, median, or mode. The mean is the average value. It is calculated by adding the individual measurements and dividing the sum by the total number of measurements. The median is the middle value. To find the median, rank all the measurements from smallest to largest and then find the measurement that is in the middle. The mode is the most common value. It is the value that occurs most often. Q: A sample of five children have the following heights: 60 cm, 58 cm, 54 cm, 62 cm, and 58 cm. What are the mean, median, and mode of this sample? A: The mean is (60 cm + 58 cm + 54 cm + 62 cm + 58 cm)  5 = 58 cm. The median and mode are both 58 cm as well. The mean, median, and mode are not always the same, as they are for this sample. In fact, sometimes these three statistics are very different from one another for the same sample. "
the mode of the set of measurements in question 8 is,(A) 2435 cm (B) 2251 cm (C) 2343 cm (D) 2098 cm,D,"The central tendency of a sample can be represented by the mean, median, or mode. The mean is the average value. It is calculated by adding the individual measurements and dividing the sum by the total number of measurements. The median is the middle value. To find the median, rank all the measurements from smallest to largest and then find the measurement that is in the middle. The mode is the most common value. It is the value that occurs most often. Q: A sample of five children have the following heights: 60 cm, 58 cm, 54 cm, 62 cm, and 58 cm. What are the mean, median, and mode of this sample? A: The mean is (60 cm + 58 cm + 54 cm + 62 cm + 58 cm)  5 = 58 cm. The median and mode are both 58 cm as well. The mean, median, and mode are not always the same, as they are for this sample. In fact, sometimes these three statistics are very different from one another for the same sample. "
terms used to describe relative direction include,(A) in (B) up (C) sideways (D) all of the above,D,"Direction can be described in relative terms, such as up, down, in, out, left, right, forward, backward, or sideways. Direction can also be described with the cardinal directions: north, south, east, or west. On maps, cardinal directions are indicated with a compass rose. You can see one in the bottom left corner of the map in the Figure 1.1. You can use the compass rose to find directions on the map. For example, to go to the school from Jordans house, you would travel from east to west. If you wanted to go on to the post office, you would change direction at the school and then travel from south to north. "
the direction of motion is a vector.,(A) true (B) false,B,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"if you are facing north, then east is to your",(A) left (B) right (C) back (D) none of the above,B,"Direction is important if you want to go between two places. Directions are expressed as north (N), east (E), south (S), and west (W), with gradations in between. The most common way to describe direction in relation to the Earths surface is with a compass, a device with a floating needle that is actually a small magnet. The compass needle aligns itself with the Earths magnetic north pole. Since the magnetic north pole is 11.5 degrees offset from its geographic north pole on the axis of rotation, you must correct for this discrepancy. Map of the Visitor Center at Old Faithful, Yellowstone National Park, Wyoming. Without using a compass, we can say that to get to Old Faithful, you enter Yellowstone National Park at the South Entrance, drive north-northeast to West Thumb, and then drive west-northwest to Old Faithful. Click image to the left or use the URL below. URL: "
english units of distance include the,(A) mile (B) square mile (C) mile per hour (D) all of the above,A,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
a millimeter is longer than a centimeter.,(A) true (B) false,B,"Youve probably been using a ruler to measure length since you were in elementary school. But you may have made most of the measurements in English units of length, such as inches and feet. In science, length is most often measured in SI units, such as millimeters and centimeters. Many rulers have both types of units, one on each edge. The ruler pictured below has only SI units. It is shown here bigger than it really is so its easier to see the small lines, which measure millimeters. The large lines and numbers stand for centimeters. Count the number of small lines from the left end of the ruler (0.0). You should count 10 lines because there are 10 millimeters in a centimeter. Q: What is the length in millimeters of the red line above the metric ruler? A: The length of the red line is 32 mm. Q: What is the length of the red line in centimeters? A: The length of the red line is 3.2 cm. "
a yard is closest in distance to a,(A) millimeter (B) centimeter (C) kilometer (D) meter,D,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
"to measure distance in si units, you could use a meter stick.",(A) true (B) false,A,"The SI unit for distance is the meter (m). Short distances may be measured in centimeters (cm), and long distances may be measured in kilometers (km). For example, you might measure the distance from the bottom to the top of a sheet of paper in centimeters and the distance from your house to your school in kilometers. "
the doppler effect can occur when the,(A) sound source is moving and the listener is stationary (B) listener is moving and the sound source is stationary (C) sound source and listener are moving together (D) two of the above,D,"The Doppler effect is a change in the frequency of sound waves that occurs when the source of the sound waves is moving relative to a stationary listener. (It can also occur when the sound source is stationary and the listener is moving.) The Figure 1.1 shows how the Doppler effect occurs. The sound waves from the police car siren travel outward in all directions. Because the car is racing forward (to the left), the sound waves get bunched up in front of the car and spread out behind it. Sound waves that are closer together have a higher frequency, and sound waves that are farther apart have a lower frequency. The frequency of sound waves, in turn, determines the pitch of the sound. Sound waves with a higher frequency produce sound with a higher pitch, and sound waves with a lower frequency produce sound with a lower pitch. "
sound waves from a police car siren move away from the car in all directions.,(A) true (B) false,A,"Look at the police car in Figure 20.6. The sound waves from its siren travel outward in all directions. Because the car is racing forward (toward the right), the sound waves get bunched up in front of the car and spread out behind it. As the car approaches the person on the right (position B), the sound waves get closer and closer together. In other words, they have a higher frequency. This makes the siren sound higher in pitch. After the car speeds by the person on the left (position A), the sound waves get more and more spread out, so they have a lower frequency. This makes the siren sound lower in pitch. A change in the frequency of sound waves, relative to a stationary listener, when the source of the sound waves is moving is called the Doppler effect. Youve probably experienced the Doppler effect yourself. The next time a vehicle with a siren races by, listen for the change in pitch. For an online animation of the Doppler effect, go to the URL below. "
sound waves that are closer together have a lower frequency.,(A) true (B) false,B,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
"as the frequency of sound waves gets lower, a listener perceives the sound to have a higher pitch.",(A) true (B) false,B,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
a police car is speeding north with its siren blaring. the sound waves from the siren increase in frequency,(A) north of the car (B) south of the car (C) in all directions around the car (D) none of the above,A,"Look at the police car in Figure 20.6. The sound waves from its siren travel outward in all directions. Because the car is racing forward (toward the right), the sound waves get bunched up in front of the car and spread out behind it. As the car approaches the person on the right (position B), the sound waves get closer and closer together. In other words, they have a higher frequency. This makes the siren sound higher in pitch. After the car speeds by the person on the left (position A), the sound waves get more and more spread out, so they have a lower frequency. This makes the siren sound lower in pitch. A change in the frequency of sound waves, relative to a stationary listener, when the source of the sound waves is moving is called the Doppler effect. Youve probably experienced the Doppler effect yourself. The next time a vehicle with a siren races by, listen for the change in pitch. For an online animation of the Doppler effect, go to the URL below. "
"if you are standing a few blocks north of the police car in question 6, how does its siren sound to you as the car gets closer to your location?",(A) The siren’s pitch gets higher (B) The siren’s pitch gets lower (C) The siren’s pitch gets lower and then higher (D) The siren’s pitch does not change,A,"As the car approaches listener A, the sound waves get closer together, increasing their frequency. This listener hears the pitch of the siren get higher. As the car speeds away from listener B, the sound waves get farther apart, decreasing their frequency. This listener hears the pitch of the siren get lower. Q: What will the siren sound like to listener A after the police car passes him? A: The siren will suddenly get lower in pitch because the sound waves will be much more spread out and have a lower frequency. "
"after the police car in question 6 passes your location, how does the siren sound to you?",(A) The siren’s pitch gets higher (B) The siren’s pitch gets lower (C) The siren’s pitch gets lower and then higher (D) The siren’s pitch does not change,B,"As the car approaches listener A, the sound waves get closer together, increasing their frequency. This listener hears the pitch of the siren get higher. As the car speeds away from listener B, the sound waves get farther apart, decreasing their frequency. This listener hears the pitch of the siren get lower. Q: What will the siren sound like to listener A after the police car passes him? A: The siren will suddenly get lower in pitch because the sound waves will be much more spread out and have a lower frequency. "
which shape of magnet does magnet earth resemble?,(A) horseshoe magnet (B) bar magnet (C) disc magnet (D) none of the above,B,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
the place generally referred to as earths magnetic north pole is located closest to,(A) 90 degrees north latitude (B) 80 degrees north latitude (C) 70 degrees north latitude (D) 60 degrees north latitude,B,"Like the real Earth, the globe pictured above is a magnet. A magnet is an object that has north and south magnetic poles and a magnetic field. The magnetic globe is a modern device, but the idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. He used a spherical magnet to represent Earth. With a compass, he demonstrated that it the spherical magnet causes a compass needle to behave the same way that Earth causes a compass needle to behave. This showed that a spherical magnet is a good model for Earth and therefore that Earth is a magnet. Q: Can you describe Earths magnetic poles and magnetic field? A: Earth has north and south magnetic poles. The North Pole is located at about 80 degrees north latitude. The magnetic field is an area around Earth that is affected by its magnetic field. The field is strongest at the poles, and lines of magnetic force move from the north to the south magnetic pole. "
earth has two north poles and two south poles.,(A) true (B) false,A,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
which of the following statements about earths magnetic field is false?,(A) It extends outward from Earth in all directions (B) It is strongest at the equator (C) Its lines of magnetic force converge at the poles (D) none of the above,B,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
a compass needle always points to earths geographic north pole.,(A) true (B) false,B,"Although the needle of a compass always points north, it doesnt point to Earths north geographic pole. Find the north geographic pole in the Figure 1.2. As you can see, it is located at 90 north latitude. Where does a compass Q: The north end of a compass needle points toward Earths north magnetic pole. The like poles of two magnets repel each other, and the opposite poles attract. So why doesnt the north end of a compass needle point to Earths south magnetic pole instead? A: The answer may surprise you. The compass needle actually does point to the south pole of magnet Earth. However, it is called the north magnetic pole because it is close to the north geographic pole. This naming convention was adopted a long time ago to avoid confusion. "
the like poles of two magnets always attract each other.,(A) true (B) false,B,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
earths magnetic field is a huge region.,(A) true (B) false,A,"Like all magnets, Earth has a magnetic field. Earths magnetic field is called the magnetosphere. It is a huge region that extends outward from Earth for several thousand kilometers but is strongest at the poles. You can see the extent of the magnetosphere in Figure 24.12. For an animated version of the magnetosphere, watch the video at this URL: MEDIA Click image to the left or use the URL below. URL: "
all machines make work easier.,(A) true (B) false,A,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
you can get more work out of a machine than you put into it.,(A) true (B) false,B,"You read above that machines do not increase the work done on an object. In other words, you cant get more work out of a machine than you put into it. In fact, machines always do less work on the object than the user does on the machine. Thats because all machines must use some of the work put into them to overcome friction. How much work? It depends on the efficiency of the machine. Efficiency is the percent of input work that becomes output work. It is a measure of how well a machine reduces friction. "
the percent of the work put into a machine (input work) that is actually used to do work (output work) is a measure of the machines,(A) power (B) efficiency (C) mechanical advantage (D) none of the above,B,"You read above that machines do not increase the work done on an object. In other words, you cant get more work out of a machine than you put into it. In fact, machines always do less work on the object than the user does on the machine. Thats because all machines must use some of the work put into them to overcome friction. How much work? It depends on the efficiency of the machine. Efficiency is the percent of input work that becomes output work. It is a measure of how well a machine reduces friction. "
which equation is used to calculate the efficiency of a machine?,(A) Efficiency = Input Distance/Output Distance x 100% (B) Efficiency = Input Force/Output Force x 100% (C) Efficiency = Input Work/Output Work x 100% (D) none of the above,D,"Efficiency can be calculated with the equation: Efficiency = Output work 100% Input work Consider a machine that puts out 6000 joules of work. To produce that much work from the machine requires the user to put in 8000 joules of work. To find the efficiency of the machine, substitute these values into the equation for efficiency: Efficiency = 6000 J 100% = 75% 8000 J You Try It! Problem: Rani puts 10,000 joules of work into a car jack. The car jack, in turn, puts out 7000 joules of work to raise up the car. What is the efficiency of the jack? "
newtons law of gravity was accepted for more than 200 years.,(A) true (B) false,A,"People have known about gravity for thousands of years. After all, they constantly experienced gravity in their daily lives. They knew that things always fall toward the ground. However, it wasnt until Sir Isaac Newton developed his law of gravity in the late 1600s that people really began to understand gravity. Newton is pictured in Figure 13.17. "
newtons law of gravity explains why gravity occurs.,(A) true (B) false,B,"In the late 1600s, Isaac Newton introduced his law of gravity, which identifies gravity as a force of attraction between all objects with mass in the universe. The law also states that the strength of gravity between two objects depends on their mass and distance apart. Newtons law of gravity was accepted for more than two centuries. It can predict the motion of most objects and was even used by NASA to land astronauts on the moon. Its still used for most practical purposes. However, Newtons law doesnt explain why gravity occurs. It only describes how gravity seems to affect objects. There are also some cases in which Newtons law doesnt even describe what happens. Q: Newton expressed his ideas about gravity as a law. A law in science is a description of what always occurs in nature. For example, according to Newtons law, objects on Earth always fall down, not up. What is needed to explain gravity? A: A theory is needed to explain gravity. In science, a theory is a broad explanation that is supported by a great deal of evidence. "
einsteins concept of gravity involves,(A) mass (B) space (C) time (D) all of the above,D,"In the early 1900s, Albert Einstein came up with a theory of gravity that actually explains gravity rather than simply describing its effects. Einstein showed mathematically that gravity is not really a force that of attraction between all objects with mass, as Newton thought. Instead, Einstein showed that gravity is a result of the warping, or curving, of space and time, which made up the same space-time fabric. These ideas about space-time and gravity became known as Einsteins theory of general relativity. "
einstein explained gravity with his theory of universal gravitation.,(A) true (B) false,B,"In the early 1900s, Albert Einstein came up with a theory of gravity that actually explains gravity rather than simply describing its effects. Einstein showed mathematically that gravity is not really a force that of attraction between all objects with mass, as Newton thought. Instead, Einstein showed that gravity is a result of the warping, or curving, of space and time, which made up the same space-time fabric. These ideas about space-time and gravity became known as Einsteins theory of general relativity. "
einstein developed his theory about gravity by using,(A) evidence (B) observations (C) mathematics (D) scientific laws,C,"In the early 1900s, Albert Einstein came up with a theory of gravity that actually explains gravity rather than simply describing its effects. Einstein showed mathematically that gravity is not really a force that of attraction between all objects with mass, as Newton thought. Instead, Einstein showed that gravity is a result of the warping, or curving, of space and time, which made up the same space-time fabric. These ideas about space-time and gravity became known as Einsteins theory of general relativity. "
"einsteins concept of gravity is similar to what happens when you place a bowling ball on the surface of a trampoline. in this analogy, if the bowling ball represents earth, then the surface of the trampoline represents",(A) space-time (B) Earth’s gravity (C) Earth’s mass (D) none of the above,A,"Einstein derived his theory using mathematics. However, you can get a good grasp of it with the help of a simple visual analogy. Imagine a bowling ball pressing down on a trampoline. The surface of the trampoline would curve downward instead of being flat. Now imagine placing a lighter ball at the edge of the trampoline. What will happen? It will roll down toward the bowling ball. This apparent attraction to the bowling ball occurs because the trampoline curves downward, not because the two balls are actually attracted to one another by an invisible force called gravity. Einstein theorized that the sun and other very massive bodies affect space and time around them in a way that is similar to the effect of the bowling ball on the trampoline. The more massive a body is, the more it causes space-time to curve. This idea is represented by the Figure 1.1. According to Einstein, objects move toward one another because of the curves in space-time, not because they are pulling on each other with a force of attraction. Einsteins theory is supported by evidence and widely accepted today, although Newtons law is still used for many calculations. "
"the less an elastic material is stretched or compressed, the greater the force it exerts.",(A) true (B) false,B,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
elastic force causes an elastic material to spring back to its original shape after being stretched or compressed.,(A) true (B) false,A,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
play objects with elasticity include,(A) spring toys (B) silly putty (C) modeling clay (D) all of the above,A,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
an elastic material offers no resistance to forces that change its shape.,(A) true (B) false,B,"Something that is elastic can return to its original shape after being stretched or compressed. This property is called elasticity. As you stretch or compress an elastic material, it resists the change in shape. It exerts a counter force in the opposite direction. This force is called elastic force. Elastic force causes the material to spring back to its original shape as soon as the stretching or compressing force is released. You can watch a demonstration of elastic force at this URL:  (3:57). MEDIA Click image to the left or use the URL below. URL: "
most of the electromagnetic radiation on earth comes from the sun.,(A) true (B) false,A,"Most of the energy that reaches the Earths surface comes from the Sun (Figure 1.1). About 44% of solar radiation is in the visible light wavelengths, but the Sun also emits infrared, ultraviolet, and other wavelengths. "
electromagnetic waves with longer wavelengths have,(A) higher frequencies (B) more energy (C) faster speeds (D) none of the above,D,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
electromagnetic waves with the longest wavelengths are,(A) gamma rays (B) X rays (C) infrared light (D) radio waves,D,"Electromagnetic waves on the left side of the Figure 1.1 are called radio waves. Radio waves are electromagnetic waves with the longest wavelengths. They may have wavelengths longer than a soccer field. They are also the electromagnetic waves with the lowest frequencies. With their low frequencies, they have the least energy of all electromagnetic waves. Nonetheless, radio waves are very useful. They are used for radio and television broadcasts and many other purposes. Click image to the left or use the URL below. URL:  Q: Based on the electromagnetic spectrum Figure 1.1, what is the range of frequencies of radio waves? A: The range of frequencies of radio waves is between 105 and 1012 Hz, or waves per second. "
electromagnetic waves with the greatest amount of energy are,(A) microwaves (B) ultraviolet light (C) infrared light (D) gamma rays,D,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
the frequencies of electromagnetic waves range from,(A) 104 to 1020 waves/second (B) 108 to 1016 waves/second (C) 1010 to 1014 waves/second (D) none of the above,A,"Although all electromagnetic waves travel at the same speed across space, they may differ in their wavelengths, frequencies, and energy levels. Wavelength is the distance between corresponding points of adjacent waves (see the Figure 1.1). Wavelengths of electromagnetic waves range from longer than a soccer field to shorter than the diameter of an atom. Wave frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second. The energy of electromagnetic waves depends on their frequency. Low-frequency waves have little energy and are normally harmless. High-frequency waves have a lot of energy and are potentially very harmful. Q: Which electromagnetic waves do you think have higher frequencies: visible light or X rays? A: X rays are harmful but visible light is harmless, so you can infer that X rays have higher frequencies than visible light. "
"the only electromagnetic waves in sunlight are ultraviolet, infrared, and visible light.",(A) true (B) false,B,"Energy from the Sun has a wide range of wavelengths. The total range of energy is called the electromagnetic spectrum. You can see it in Figure 15.8. Visible light is the only light that humans can see. Different wavelengths of visible light appear as different colors. Radio waves have the longest wavelengths. They also have the least amount of energy. Infrared light has wavelengths too long for humans to see, but we can feel them as heat. The atmosphere absorbs the infrared light. Ultraviolet (UV) light is in wavelengths too short for humans to see. The most energetic UV light is harmful to life. The atmosphere absorbs most of this UV light from the Sun. Gamma rays have the highest energy and they are the most damaging rays. Fortunately, gamma rays dont penetrate Earths atmosphere. "
ultraviolet light has more energy than visible light.,(A) true (B) false,A,"Energy from the Sun has a wide range of wavelengths. The total range of energy is called the electromagnetic spectrum. You can see it in Figure 15.8. Visible light is the only light that humans can see. Different wavelengths of visible light appear as different colors. Radio waves have the longest wavelengths. They also have the least amount of energy. Infrared light has wavelengths too long for humans to see, but we can feel them as heat. The atmosphere absorbs the infrared light. Ultraviolet (UV) light is in wavelengths too short for humans to see. The most energetic UV light is harmful to life. The atmosphere absorbs most of this UV light from the Sun. Gamma rays have the highest energy and they are the most damaging rays. Fortunately, gamma rays dont penetrate Earths atmosphere. "
electromagnetic waves need a medium in order to transfer energy.,(A) true (B) false,B,"Unlike a mechanical transverse wave, which requires a medium, an electromagnetic transverse wave can travel through space without a medium. Waves traveling through a medium lose some energy to the medium. However, when an electromagnetic wave travels through space, no energy is lost, so the wave doesnt get weaker as it travels. However, the energy is ""diluted"" as it spreads out over an ever-larger area as it travels away from the source. This is similar to the way a sound wave spreads out and becomes less intense farther from the sound source. "
electromagnetic waves,(A) create force fields (B) exert force over a distance (C) can travel through outer space (D) all of the above,D,"Electromagnetic waves are waves that carry energy through matter or space as vibrating electric and magnetic fields. Electromagnetic waves have a wide range of wavelengths and frequencies. Sunlight contains the complete range of wavelengths of electromagnetic waves, which is called the electromagnetic spectrum. The Figure 1.1 shows all the waves in the spectrum. "
electromagnetic waves are,(A) surface waves (B) transverse waves (C) longitudinal waves (D) none of the above,B,"Electromagnetic waves are waves that carry energy through matter or space as vibrating electric and magnetic fields. Electromagnetic waves have a wide range of wavelengths and frequencies. Sunlight contains the complete range of wavelengths of electromagnetic waves, which is called the electromagnetic spectrum. The Figure 1.1 shows all the waves in the spectrum. "
when electromagnetic waves strike matter they may be,(A) absorbed (B) reflected (C) refracted (D) any of the above,D,"When electromagnetic waves strike matter, they may interact with it in the same ways that mechanical waves interact with matter. Electromagnetic waves may: reflect, or bounce back from a surface; refract, or bend when entering a new medium; diffract, or spread out around obstacles. Electromagnetic waves may also be absorbed by matter and converted to other forms of energy. Microwaves are a familiar example. When microwaves strike food in a microwave oven, they are absorbed and converted to thermal energy, which heats the food. "
electromagnetic waves may be converted to other forms of energy.,(A) true (B) false,A,"Electromagnetic waves can travel through matter as well as across space. When they strike matter, they interact with it in the same ways that mechanical waves interact with matter. They may reflect (bounce back), refract (bend when traveling through different materials), or diffract (bend around objects). They may also be converted to other forms of energy. Microwaves are a familiar example. They are a type of electromagnetic wave that you can read about later on in this chapter, in the lesson ""The Electromagnetic Spectrum."" When microwaves strike food in a microwave oven, they are converted to thermal energy, which heats the food. "
orbitals may be shaped like,(A) spheres (B) dumbbells (C) rings (D) all of the above,D,"The atomic model above is useful for some purposes, but its too simple when it comes to the location of electrons. In reality, its impossible to say what path an electron will follow. Instead, its only possible to describe the chances of finding an electron in a certain region around the nucleus. The region where an electron is most likely to be is called an orbital. Each orbital can have at most two electrons. Some orbitals, called S orbitals, are shaped like spheres, with the nucleus in the center. An S orbital is pictured in Figure 1.2. Where the dots are denser, the chance of finding an electron is greater. Also pictured in Figure 1.2 is a P orbital. P orbitals are shaped like dumbbells, with the nucleus in the pinched part of the dumbbell. Click image to the left or use the URL below. URL:  Q: How many electrons can there be in each type of orbital shown above? A: There can be a maximum of two electrons in any orbital, regardless of its shape. Q: Where is the nucleus in each orbital? A: The nucleus is at the center of each orbital. It is in the middle of the sphere in the S orbital and in the pinched part of the P orbital. "
the atomic nucleus is always at the center of an orbital.,(A) true (B) false,A,"The atomic model above is useful for some purposes, but its too simple when it comes to the location of electrons. In reality, its impossible to say what path an electron will follow. Instead, its only possible to describe the chances of finding an electron in a certain region around the nucleus. The region where an electron is most likely to be is called an orbital. Each orbital can have at most two electrons. Some orbitals, called S orbitals, are shaped like spheres, with the nucleus in the center. An S orbital is pictured in Figure 1.2. Where the dots are denser, the chance of finding an electron is greater. Also pictured in Figure 1.2 is a P orbital. P orbitals are shaped like dumbbells, with the nucleus in the pinched part of the dumbbell. Click image to the left or use the URL below. URL:  Q: How many electrons can there be in each type of orbital shown above? A: There can be a maximum of two electrons in any orbital, regardless of its shape. Q: Where is the nucleus in each orbital? A: The nucleus is at the center of each orbital. It is in the middle of the sphere in the S orbital and in the pinched part of the P orbital. "
schroedinger thought that electrons,(A) are restricted to very specific orbits (B) might travel in waves like light (C) have very precise locations (D) behave like protons and neutrons,B,"In the mid-1920s, an Austrian scientist named Erwin Schrdinger thought that the problem with Bohrs model was restricting the electrons to specific orbits. He wondered if electrons might behave like light, which scientists already knew had properties of both particles and waves. Schrdinger speculated that electrons might also travel in waves. Q: How do you pin down the location of an electron in a wave? A: You cant specify the exact location of an electron. However, Schrdinger showed that you can at least determine where an electron is most likely to be. Schrdinger developed an equation that could be used to calculate the chances of an electron being in any given place around the nucleus. Based on his calculations, he identified regions around the nucleus where electrons are most likely to be. He called these regions orbitals. As you can see in the Figure 1.2, orbitals may be shaped like spheres, dumbbells, or rings. In each case, the nucleus of the atom is at the center of the orbital. "
bohrs atomic model explains all of the behaviors of electrons in atoms of all elements.,(A) true (B) false,B,"Up until about 1920, scientists accepted Niels Bohrs model of the atom. In this model, negative electrons circle the positive nucleus at fixed distances from the nucleus, called energy levels. You can see the model in Figure 1.1 for an atom of the element nitrogen. Bohrs model is useful for understanding properties of elements and their chemical interactions. However, it doesnt explain certain behaviors of electrons, except for those in the simplest atom, the hydrogen atom. "
the electron cloud model of the atom is no longer accepted by most scientists.,(A) true (B) false,B,"Today, these ideas about electrons are represented by the electron cloud model. The electron cloud is an area around the nucleus where electrons are likely to be. Figure 5.17 shows an electron cloud model for a helium atom. "
"like protons and neutrons, electrons consist of smaller particles.",(A) true (B) false,B,"Although atoms are very tiny, they consist of even smaller particles. Atoms are made of protons, neutrons, and electrons: Protons have a positive charge. Electrons have a negative charge. Neutrons are neutral in charge. "
an electron has an electrical charge of,(A) +1 (B) -1 (C) 0 (D) 0 or -1,B,"An electron is a particle outside the nucleus of an atom that has a negative electric charge. The charge of an electron is opposite but equal to the charge of a proton. Atoms have the same number of electrons as protons. As a result, the negative and positive charges ""cancel out."" This makes atoms electrically neutral. For example, a carbon atom has six electrons that ""cancel out"" its six protons. "
an electron has about the same mass as a proton.,(A) true (B) false,B,"Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges cancel out, making atoms electrically neutral. "
atoms always have the same number of electrons as protons.,(A) true (B) false,A,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
what is the maximum number of electrons each orbital can hold?,(A) 1 (B) 2 (C) 4 (D) 8,B,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
no two elements are exactly alike.,(A) true (B) false,A,"Every organism is different from every other organism. Every organisms genes are different, too. "
which of the following substances is not an element?,(A) oxygen (B) water (C) nitrogen (D) hydrogen,B,"A pure substance is called an element. An element is a pure substance because it cannot be separated into any other substances. Currently, 92 different elements are known to exist in nature, although additional elements have been formed in labs. All matter consists of one or more of these elements. Some elements are very common; others are relatively rare. The most common element in the universe is hydrogen, which is part of Earths atmosphere and a component of water. The most common element in Earths atmosphere is nitrogen, and the most common element in Earths crust is oxygen. Click image to the left or use the URL below. URL: "
which element is attracted by a magnet?,(A) silver (B) aluminum (C) lead (D) iron,D,"A magnet is an object that attracts certain materials such as iron. Youre probably familiar with common bar magnets, like the one in Figure 24.2. Like all magnets, this bar magnet has north and south poles and attracts objects such as paper clips that contain iron. "
which element glows red when electricity flows through it?,(A) iron (B) mercury (C) neon (D) copper,C,"Think about the coil of an electric stove as it heats up. The coil changes in color as its temperature rises. When you first turn on the heat, the coil looks black. The air a few inches above the coil begins to feel warm. As the coil gets hotter, it starts to glow a dull red. As it gets even hotter, it becomes a brighter red. Next it turns orange. If it gets extremely hot, it might look yellow-white, or even blue-white. Like a coil on a stove, a stars color is determined by the temperature of the stars surface. Relatively cool stars are red. Warmer stars are orange or yellow. Extremely hot stars are blue or blue-white. "
carbon is the most common element in living things.,(A) true (B) false,A,"Carbon is a very important element to living things. As the second most common element in the human body, we know that human life without carbon would not be possible. Protein, carbohydrates, and fats are all part of the body and all contain carbon. When your body breaks down food to produce energy, you break down protein, carbohydrates, and fat, and you breathe out carbon dioxide. Carbon occurs in many forms on Earth. The element moves through organisms and then returns to the environment. When all this happens in balance, the ecosystem remains in balance too. "
aristotle correctly identified four of the elements.,(A) true (B) false,B,"For thousands of years, people have wondered about the substances that make up matter. About 2500 years ago, the Greek philosopher Aristotle argued that all matter is made up of just four elements, which he identified as earth, air, water, and fire. He thought that different substances vary in their properties because they contain different proportions of these four elements. Aristotle had the right idea, but he was wrong about which substances are elements. Nonetheless, his four elements were accepted until just a few hundred years ago. Then scientists started discovering many of the elements with which we are familiar today. Eventually they discovered dozens of different elements. "
the smallest particle of an element is a(n),(A) molecule (B) crystal (C) compound (D) atom,D,"The smallest particle of an element that still has the elements properties is an atom. All the atoms of an element are alike, and they are different from the atoms of all other elements. For example, atoms of gold are the same whether they are found in a gold nugget or a gold ring (see Figure 3.8). All gold atoms have the same structure and properties. "
only endothermic chemical reactions involve energy.,(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called endothermic reactions, less energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of exothermic reactions. In an exothermic reaction, it takes less energy to break bonds in the reactants than is released when new bonds form in the products. "
"in an endothermic reaction, it takes less energy to break bonds in the reactants than is released when new bonds form in the products.",(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called endothermic reactions, less energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of exothermic reactions. In an exothermic reaction, it takes less energy to break bonds in the reactants than is released when new bonds form in the products. "
a constant input of energy is needed to keep an endothermic reaction going.,(A) true (B) false,A,"The word endothermic literally means taking in heat. A constant input of energy, often in the form of heat, is needed to keep an endothermic reaction going. This is illustrated in the Figure 1.1. Energy must be constantly added because not enough energy is released when the products form to break more bonds in the reactants. The general equation for an endothermic reaction is: Reactants + Energy  Products Note: H represents the change in en- ergy. In endothermic reactions, the temperature of the products is typically lower than the temperature of the reactants. The drop in temperature may be great enough to cause liquids to freeze. Q: Now can you guess how an instant cold pack works? A: Squeezing the cold pack breaks an inner bag of water, and the water mixes with a chemical inside the pack. The chemical and water combine in an endothermic reaction. The energy needed for the reaction to take place comes from the water, which gets colder as the reaction proceeds. "
which statement about the chemical reactions of photosynthesis is true?,(A) They are endothermic (B) They produce energy in the form of light (C) They can be represented by 6CO2 + 6H2O → C6H12O6 + 6O2 (D) two of the above,D,"Some of the most important biochemical reactions are the reactions involved in photosynthesis and cellular respira- tion. Together, these two processes provide energy to almost all of Earths organisms. The two processes are closely related, as you can see in the Figure 1.1. In photosynthesis, light energy from the sun is converted to stored chemical energy in glucose. In cellular respiration, stored energy is released from glucose and stored in smaller amounts that cells can use. A: In photosynthesis, carbon dioxide (CO2 ) and water (H2 O) are the reactants. They combine using energy from light to produce oxygen (O2 ) and glucose (C6 H12 O6 ). Oxygen and glucose, in turn, are the reactants in cellular respiration. They combine to produce carbon dioxide, water, and energy. "
"during an endothermic reaction, energy is",(A) absorbed (B) released (C) destroyed (D) created,A,"Whether a reaction absorbs energy or releases energy, there is no overall change in the amount of energy. Energy cannot be created or destroyed. This is the law of conservation of energy. Energy can change form for example, from electricity to light but the same amount of energy always remains. If energy cannot be destroyed, what happens to the energy that is absorbed in an endothermic reaction? The energy is stored in the chemical bonds of the products. This form of energy is called chemical energy. In an endothermic reaction, the products have more stored chemical energy than the reactants. In an exothermic reaction, the opposite is true. The products have less stored chemical energy than the reactants. The excess energy in the reactants is released to the surroundings when the reaction occurs. The graphs in Figure 8.14 show the chemical energy of reactants and products in each type of reaction. "
"when work is done, energy is transferred from one object to another.",(A) true (B) false,A,"Energy is defined in science as the ability to move matter or change matter in some other way. Energy can also be defined as the ability to do work, which means using force to move an object over a distance. When work is done, energy is transferred from one object to another. For example, when the boy in the Figure 1.1 uses force to swing the racket, he transfers some of his energy to the racket. Q: It takes energy to play tennis. Where does this boy get his energy? A: He gets energy from the food he eats. "
the si unit for energy is the newton.,(A) true (B) false,B,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
forms of energy include,(A) chemical energy (B) mechanical energy (C) thermal energy (D) all of the above,D,"Energy, or the ability to cause changes in matter, can exist in many different forms. Energy can also change from one form to another. The photo above of the guitar player represents six forms of energy: mechanical, chemical, electrical, light, thermal, and sound energy. Another form of energy is nuclear energy. Q: Can you find the six different forms of energy in the photo of the guitar player (See opening image)? A: The guitarist uses mechanical energy to pluck the strings of the guitar. He gets the energy he needs to perform from chemical energy in food he ate earlier in the day. The stage lights use electrical energy, which they change to light energy and thermal energy (commonly called heat). The guitar produces sound energy when the guitarist plucks the strings. "
anything that is moving has kinetic energy.,(A) true (B) false,A,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
"when you run around a track, which type of energy are you demonstrating?",(A) mechanical energy (B) potential energy (C) kinetic energy (D) two of the above,D,There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of other examples? 
energy conversion means saving energy.,(A) true (B) false,B,"Everyone can reduce their use of energy resources and the pollution the resources cause by conserving energy. Conservation means saving resources by using them more efficiently, using less of them, or not using them at all. You can read below about some of the ways you can conserve energy on the road and in the home. "
most electricity comes from the burning of,(A) fossil fuels (B) trash (C) wood (D) none of the above,A,"Around the world, coal is the largest source of energy for electricity. The United States is rich in coal (Figure 1.3). California once had a number of small coal mines, but the state no longer produces coal. To turn coal into electricity, the rock is crushed into powder, which is then burned in a furnace that has a boiler. Like other fuels, coal releases its energy as heat when it burns. Heat from the burning coal boils the water in the boiler to make steam. The steam spins turbines, which turn generators to create electricity. In this way, the energy stored in the coal is converted to useful energy like electricity. "
any form of energy can change into any other form of energy.,(A) true (B) false,A,"Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, when wood burns, the woods chemical energy changes to both thermal energy and light energy. Other examples of energy conversions are described in Figure 17.16. You can see still others at this URL: http://fi.edu/guide/hughes/energychangeex.html . You can check your understanding of how energy changes form by doing the quizzes at these URLs:  Energy is conserved in energy conversions. No energy is lost when energy changes form, although some may be released as thermal energy due to friction. For example, not all of the energy put into a steam turbine in Figure 17.16 changes to electrical energy. Some changes to thermal energy because of friction of the turning blades and other moving parts. The more efficient a device is, the greater the percentage of usable energy it produces. Appliances with an ""Energy Star"" label like the one in Figure 17.17 use energy efficiently and thereby reduce energy use. "
one form of energy can change into two or more other forms of energy.,(A) true (B) false,A,"Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, when wood burns, the woods chemical energy changes to both thermal energy and light energy. Other examples of energy conversions are described in Figure 17.16. You can see still others at this URL: http://fi.edu/guide/hughes/energychangeex.html . You can check your understanding of how energy changes form by doing the quizzes at these URLs:  Energy is conserved in energy conversions. No energy is lost when energy changes form, although some may be released as thermal energy due to friction. For example, not all of the energy put into a steam turbine in Figure 17.16 changes to electrical energy. Some changes to thermal energy because of friction of the turning blades and other moving parts. The more efficient a device is, the greater the percentage of usable energy it produces. Appliances with an ""Energy Star"" label like the one in Figure 17.17 use energy efficiently and thereby reduce energy use. "
examples of the energy conversion described in question 8 include,(A) using a playground slide (B) going up and down stairs (C) bouncing on a trampoline (D) all of the above,D,There are many other examples of energy conversions between potential and kinetic energy. Figure 17.7 describes how potential energy changes to kinetic energy and back again on swings and trampolines. You can see an animation of changes between potential and kinetic energy on a ramp at the URL below. Can you think of other examples? 
electrons can occupy the spaces between energy levels.,(A) true (B) false,B,"Basic to Bohrs model is the idea of energy levels. Energy levels are areas located at fixed distances from the nucleus of the atom. They are the only places where electrons can be found. Energy levels are a little like rungs on a ladder. You can stand on one rung or another but not between the rungs. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model of an atom in Figure 5.15 has six energy levels. The level with the least energy is the one closest to the nucleus. As you go farther from the nucleus, the levels have more and more energy. Electrons can jump from one energy level to another. If an atom absorbs energy, some of its electrons can jump to a higher energy level. If electrons jump to a lower energy level, the atom emits, or gives off, energy. You can see an animation at this happening at the URL below. "
electrons in the first energy level have the least amount of energy.,(A) true (B) false,A,"Energy levels (also called electron shells) are fixed distances from the nucleus of an atom where electrons may be found. Electrons are tiny, negatively charged particles in an atom that move around the positive nucleus at the center. Energy levels are a little like the steps of a staircase. You can stand on one step or another but not in between the steps. The same goes for electrons. They can occupy one energy level or another but not the space between energy levels. The model in the Figure 1.1 shows the first four energy levels of an atom. Electrons in energy level I (also called energy level K) have the least amount of energy. As you go farther from the nucleus, electrons at higher levels have more energy, and their energy increases by a fixed, discrete amount. Electrons can jump from a lower to the next higher energy level if they absorb this amount of energy. Conversely, if electrons jump from a higher to a lower energy level, they give off energy, often in the form of light. This explains the fireworks pictured above. When the fireworks explode, electrons gain energy and jump to higher energy levels. When they jump back to their original energy levels, they release the energy as light. Different atoms have different arrangements of electrons, so they give off light of different colors. Q: In the atomic model Figure 1.1, where would you find electrons that have the most energy? A: Electrons with the most energy would be found in energy level IV. "
"if an atom has just three electrons, they will be located in energy level(s)",(A) I and II (B) I (C) II (D) and III (E) c I only (F) d I or II,A,"Electrons are located at fixed distances from the nucleus, called energy levels. You can see the first three energy levels in the Figure 1.3. The diagram also shows the maximum possible number of electrons at each energy level. Electrons at lower energy levels, which are closer to the nucleus, have less energy. At the lowest energy level, which has the least energy, there is just one orbital, so this energy level has a maximum of two electrons. Only when a lower energy level is full are electrons added to the next higher energy level. Electrons at higher energy levels, which are farther from the nucleus, have more energy. They also have more orbitals and greater possible numbers of electrons. Electrons at the outermost energy level of an atom are called valence electrons. They determine many of the properties of an element. Thats because these electrons are involved in chemical reactions with other atoms. Atoms may share or transfer valence electrons. Shared electrons bind atoms together to form chemical compounds. Q: If an atom has 12 electrons, how will they be distributed in energy levels? A: The atom will have two electrons at the first energy level, eight at the second energy level, and the remaining two at the third energy level. Q: Sometimes, an electron jumps from one energy level to another. How do you think this happens? A: To change energy levels, an electron must either gain or lose energy. Thats because electrons at higher energy levels have more energy than electrons at lower energy levels. "
how many electrons can each orbital hold?,(A) 1 (B) 2 (C) 3 (D) 4,B,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
any atom is most stable when its outermost energy level contains,(A) a maximum of two electrons (B) a total of eight electrons (C) as many electrons as it can hold (D) fewer electrons than it can hold,C,"Electrons in the outermost energy level of an atom have a special significance. These electrons are called valence electrons, and they determine many of the properties of an atom. An atom is most stable if its outermost energy level contains as many electrons as it can hold. For example, helium has two electrons, both in the first energy level. This energy level can hold only two electrons, so heliums only energy level is full. This makes helium a very stable element. In other words, its atoms are unlikely to react with other atoms. Consider the elements fluorine and lithium, modeled in the Figure 1.3. Fluorine has seven of eight possible electrons in its outermost energy level, which is energy level II. It would be more stable if it had one more electron because this would fill its outermost energy level. Lithium, on the other hand, has just one of eight possible electrons in its outermost energy level (also energy level II). It would be more stable if it had one less electron because it would have a full outer energy level (now energy level I). Both fluorine and lithium are highly reactive elements because of their number of valence electrons. Fluorine will readily gain one electron and lithium will just as readily give up one electron to become more stable. In fact, lithium and fluorine will react together as shown in the Figure 1.4. When the two elements react, lithium transfers its one extra electron to fluorine. Q: A neon atom has ten electrons. How many electrons does it have in its outermost energy level? How stable do you think a neon atom is? A: A neon atom has two electrons in energy level I and its remaining eight electrons in energy level II, which can "
valence electrons determine how reactive an element is.,(A) true (B) false,A,"Valence electrons are the electrons in the outer energy level of an atom that can participate in interactions with other atoms. Valence electrons are generally the electrons that are farthest from the nucleus. As a result, they may be attracted as much or more by the nucleus of another atom than they are by their own nucleus. "
enzymes work by providing activation energy.,(A) true (B) false,B,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
enzymes are used up in the reactions they catalyze.,(A) true (B) false,B,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
a human enzyme that helps digest starch is,(A) pepsase (B) starchase (C) amylase (D) glucase,C,"Chemical reactions constantly occur inside living things. Many of these reactions require catalysts so they will occur quickly enough to support life. Catalysts in living things are called enzymes. Enzymes may be extremely effective. A reaction that takes a split second to occur with an enzyme might take many years without it! More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. An example is amylase, which is found in the mouth and small intestine. Amylase catalyzes the breakdown of starch to sugar. You can see how it affects the rate of starch digestion in the Figure 1.2. A: The starches in the cracker start to break down to sugars with the help of the enzyme amylase. Try this yourself and see if you can taste the reaction. "
which of the following statements about enzymes if false?,(A) Enzymes are highly specialized for the reactions they catalyze (B) Enzymes are very effective at speeding up reactions (C) Enzymes are very efficient at catalyzing reactions (D) Enzymes usually result in the formation of waste products,D,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
about 100 different enzymes are needed for human life.,(A) true (B) false,B,More than 1000 different enzymes are necessary for human life. Many enzymes are needed for the digestion of food. Two examples are amylase and pepsin. Both are described in the Figure 1.2. 
enzymes are,(A) proteins (B) encoded in DNA (C) made in the cells where they are needed (D) all of the above,D,"Enzymes are proteins that increase the rate of chemical reactions by reducing the amount of activation energy needed for reactants to start reacting. Enzymes are synthesized in the cells that need them, based on instructions encoded in the cells DNA. Enzymes arent changed or used up in the reactions they catalyze, so they can be used to speed up the same reaction over and over again. Enzymes are highly specific for certain chemical reactions, so they are very effective. A reaction that would take years to occur without its enzyme might occur in a split second with the enzyme. Enzymes are also very efficient, so waste products rarely form. "
"in an exothermic reaction, the reactants have more stored chemical energy than the products.",(A) true (B) false,A,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
"in an exothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products.",(A) true (B) false,B,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In some chemical reactions, called exothermic reactions, more energy is released when new bonds form in the products than is needed to break bonds in the reactants. The opposite is true of endothermic reactions. In an endothermic reaction, it takes more energy to break bonds in the reactants than is released when new bonds form in the products. "
all combustion reactions are exothermic reactions.,(A) true (B) false,A,"All combustion reactions are exothermic reactions. During a combustion reaction, a substance burns as it combines with oxygen. When substances burn, they usually give off energy as heat and light. Look at the big bonfire in the Figure 1.2. The combustion of wood is an exothermic reaction that releases a lot of energy as heat and light. You can see the light energy the fire is giving off. If you were standing near the fire, you would also feel its heat. "
which of the following reactions is exothermic?,(A) CH4 + F2 → CH3F + HF (B) CH4 + 2O2 → CO2 + 2H2O (C) 2H2O → 2H2 + O2 (D) two of the above,D,"All chemical reactions involve energy. Energy is used to break bonds in reactants, and energy is released when new bonds form in products. In terms of energy, there are two types of chemical reactions: endothermic reactions and exothermic reactions. In exothermic reactions, more energy is released when bonds form in products than is used to break bonds in reactants. These reactions release energy to the environment, often in the form of heat or light. In endothermic reactions, more energy is used to break bonds in reactants than is released when bonds form in products. These reactions absorb energy from the environment. Q: When it comes to energy, which type of reaction is the burning of wood? Is it an endothermic reaction or an exothermic reaction? How can you tell? A: The burning of wood is an exothermic reaction. You can tell by the heat and light energy given off by a wood fire. "
a steam engine is an external combustion engine.,(A) true (B) false,A,"An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other device. Figure 18.15 explains in greater detail how this type of engine works. You can see an animated version of an external combustion engine at this URL: http://science.howstuffworks.com/transport/engines-equipment/steam1.htm . "
an external combustion engine,(A) burns fuel outside the engine (B) changes kinetic energy to thermal energy (C) runs on electricity (D) all of the above,A,"An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other device. Figure 18.15 explains in greater detail how this type of engine works. You can see an animated version of an external combustion engine at this URL: http://science.howstuffworks.com/transport/engines-equipment/steam1.htm . "
the kinetic energy of an external combustion engine can be used to,(A) turn the wheels of a vehicle (B) turn a turbine (C) run other machines (D) all of the above,D,"An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy, which is used to heat water and change it to steam. The pressure of the steam moves a piston back and forth inside a cylinder. The kinetic energy of the moving piston can be used to turn a vehicles wheels, a turbine, or other mechanical device. The Figure 1.1 explains in greater detail how this type of engine works. Q: What type of energy does the piston have when it moves back and forth inside the cylinder? A: Like anything else that is moving, the moving piston has kinetic energy. "
an external combustion engine burns fuel to heat air.,(A) true (B) false,B,"An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other device. Figure 18.15 explains in greater detail how this type of engine works. You can see an animated version of an external combustion engine at this URL: http://science.howstuffworks.com/transport/engines-equipment/steam1.htm . "
external combustion engines are no longer in use today.,(A) true (B) false,B,"An external combustion engine burns fuel externally, or outside the engine. The burning fuel releases thermal energy that is used to turn water to steam. The pressure of the steam is then used to move a piston back and forth in a cylinder. The kinetic energy of the moving piston can be used to turn a turbine or other device. Figure 18.15 explains in greater detail how this type of engine works. You can see an animated version of an external combustion engine at this URL: http://science.howstuffworks.com/transport/engines-equipment/steam1.htm . "
all materials respond to magnetic force.,(A) true (B) false,B,"Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. No doubt youve handled refrigerator magnets like the ones in Figure 24.5. You probably know first-hand that they stick to a metal refrigerator but not to surfaces such as wooden doors and glass windows. Wood and glass arent attracted to a magnet, whereas the steel refrigerator is. Obviously, only certain materials respond to magnetic force. "
nonmagnetic materials include,(A) wood (B) glass (C) plastic (D) all of the above,D,"Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the materials have no magnetic properties. Also, in most types of matter, the north and south poles of atoms point in all different directions, so overall the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, electrons fill the orbitals of the atoms that make up the material in a way to allow for each atom to have a tiny magnetic field, giving each atom a tiny north and south pole. There are large areas where the north and south poles of atoms are all lined up in the same direction. These areas are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized by placing it in a magnetic field. When this happens, all the magnetic domains become aligned, and the material becomes a magnet. This is illustrated in Figure 24.6. Materials that can be magnetized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
magnetism is due to the movement of electrons within atoms.,(A) true (B) false,A,"Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the electrons orbiting the nuclei of the atoms are arranged in such a way that the materials have no magnetic properties. Also, in most types of matter, the north and south poles of atoms point in all different directions, so overall the matter is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, electrons fill the orbitals of the atoms that make up the material in a way to allow for each atom to have a tiny magnetic field, giving each atom a tiny north and south pole. There are large areas where the north and south poles of atoms are all lined up in the same direction. These areas are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized by placing it in a magnetic field. When this happens, all the magnetic domains become aligned, and the material becomes a magnet. This is illustrated in Figure 24.6. Materials that can be magnetized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
all of the following materials can be magnetized except,(A) iron (B) carbon (C) cobalt (D) nickel,B,"Magnetism is the ability of a material to be attracted by a magnet and to act as a magnet. Magnetism is due to the movement of electrons within atoms of matter. When electrons spin around the nucleus of an atom, it causes the atom to become a tiny magnet, with north and south poles and a magnetic field. In most materials, the north and south poles of atoms point in all different directions, so overall the material is not magnetic. Examples of nonmagnetic materials include wood, glass, plastic, paper, copper, and aluminum. These materials are not attracted to magnets and cannot become magnets. In other materials, there are regions where the north and south poles of atoms are all lined up in the same direction. These regions are called magnetic domains. Generally, the magnetic domains point in different directions, so the material is still not magnetic. However, the material can be magnetized (made into a magnet) by placing it in a magnetic field. When this happens, all the magnetic domains line up, and the material becomes a magnet. You can see this in the Figure 1.1. Materials that can be magnitized are called ferromagnetic materials. They include iron, cobalt, and nickel. "
"if you stroke an iron nail with a bar magnet, the nail will become a temporary magnet.",(A) true (B) false,B,"Materials that have been magnetized may become temporary or permanent magnets. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains line up. As a result, the paper clips will stick to the magnet and also to each other (see the Figure 1.2). However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. You can see how its done in the Figure 1.3. The nails magnetic domains will remain aligned even after you remove the nail from the magnetic field of the bar magnet. Q: Even permanent magnets can be demagnetized if they are dropped or heated to high temperatures. Can you explain why? "
a permanent magnet can be demagnetized by,(A) dropping it (B) heating it (C) cooling it (D) two of the above,D,"Materials that have been magnetized may become temporary or permanent magnets. An example of each type of magnet is described below. Both are demonstrated in Figure 24.7. If you bring a bar magnet close to pile of paper clips, the paper clips will become temporarily magnetized, as all their magnetic domains align. As a result, the paper clips will stick to the magnet and also to each other. However, if you remove the paper clips from the bar magnets magnetic field, their magnetic domains will no longer align. As a result, the paper clips will no longer be magnetized or stick together. If you stroke an iron nail with a bar magnet, the nail will become a permanent (or at least long-lasting) magnet. Its magnetic domains will remain aligned even after you remove it from the magnetic field of the bar magnet. Permanent magnets can be demagnetized, however, if they are dropped or heated to high temperatures. These actions move the magnetic domains out of alignment. "
fundamental forces of the universe include,(A) gravity (B) friction (C) electromagnetic force (D) two of the above,D,"The interactions of matter particles are subject to four fundamental forces: gravity, electromagnetic force, weak nuclear force, and strong nuclear force. All of these forces are thought to be transmitted by bosons, the force- carrying fundamental particles. The different types of bosons and the forces they carry are shown in Table 1.2. Consider the examples of gluons, the bosons that carry the strong nuclear force. A continuous exchange of gluons between quarks binds them together in both protons and neutrons. Note that force-carrying particles for gravity (gravitons) have not yet been found. Type of Bosons Gluons Fundamental Force They Carry strong nuclear force Particles They Affect quarks Distance over Which They Carry Force only within the nucleus Type of Bosons W bosons Z bosons Photons Gravitons (hypothetical) Fundamental Force They Carry weak nuclear force Particles They Affect leptons and quarks Distance over Which They Carry Force only within the nucleus electromagnetic force force of gravity leptons and quarks leptons and quarks all distances all distances Q: Which type of boson carries force between the negative electrons and positive protons of an atom? A: Photons carry electromagnetic force. They are responsible for the force of attraction or repulsion between all electrically charged matter, including the force of attraction between negative electrons and positive protons in an atom. Q: Gravitons have not yet been discovered so they have only been hypothesized to exist. What evidence do you think leads scientists to think that these hypothetical particles affect both leptons and quarks and that they carry force over all distances? A: Gravity is known to affect all matter that has mass, and both quarks and leptons have mass. Gravity is also known to work over long as well as short distances. For example, Earths gravity keeps you firmly planted on the ground and also keeps the moon orbiting around the planet. "
the main forces that affect the motion of everyday objects include,(A) gravity (B) friction (C) applied force (D) all of the above,D,"Force is defined as a push or pull acting on an object. There are several fundamental forces in the universe, including the force of gravity, electromagnetic force, and weak and strong nuclear forces. When it comes to the motion of everyday objects, however, the forces of interest include mainly gravity, friction, and applied force. Applied force is force that a person or thing applies to an object. Q: What forces act on Carsons scooter? A: Gravity, friction, and applied forces all act on Carsons scooter. Gravity keeps pulling both Carson and the scooter toward the ground. Friction between the wheels of the scooter and the ground prevent the scooter from sliding but also slow it down. In addition, Carson applies forces to his scooter to control its speed and direction. "
only some changes in speed or direction are caused by forces.,(A) true (B) false,B,"Newtons first law of motion states that an objects motion will not change unless an unbalanced force acts on the object. If the object is at rest, it will stay at rest. If the object is in motion, it will stay in motion and its velocity will remain the same. In other words, neither the direction nor the speed of the object will change as long as the net force acting on it is zero. You can watch a video about Newtons first law at this URL: http://videos.howstuffworks.com/ Look at the pool balls in Figure 14.2. When a pool player pushes the pool stick against the white ball, the white ball is set into motion. Once the white ball is rolling, it rolls all the way across the table and stops moving only after it crashes into the cluster of colored balls. Then, the force of the collision starts the colored balls moving. Some may roll until they bounce off the raised sides of the table. Some may fall down into the holes at the edges of the table. None of these motions will occur, however, unless that initial push of the pool stick is applied. As long as the net force on the balls is zero, they will remain at rest. "
the force required to change an objects motion depends on the objects mass.,(A) true (B) false,A,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
force is a vector.,(A) true (B) false,A,"Force is a vector because it has both size and direction. For example, the girl in Figure 13.1 is pushing the swing away from herself. Thats the direction of the force. She can give the swing a strong push or a weak push. Thats the size, or strength, of the force. Like other vectors, forces can be represented with arrows. Figure 13.2 shows some examples. The length of each arrow represents the strength of the force, and the way the arrow points represents the direction of the force. How could you use an arrow to represent the girls push on the swing in Figure 13.1? "
energy can change from one form to another.,(A) true (B) false,A,"Energy often changes from one form to another. For example, the mechanical energy of a moving drumstick changes to sound energy when it strikes the drumhead and causes it to vibrate. Any form of energy can change into any other form. Frequently, one form of energy changes into two or more different forms. For example, when wood burns, the woods chemical energy changes to both thermal energy and light energy. Other examples of energy conversions are described in Figure 17.16. You can see still others at this URL: http://fi.edu/guide/hughes/energychangeex.html . You can check your understanding of how energy changes form by doing the quizzes at these URLs:  Energy is conserved in energy conversions. No energy is lost when energy changes form, although some may be released as thermal energy due to friction. For example, not all of the energy put into a steam turbine in Figure 17.16 changes to electrical energy. Some changes to thermal energy because of friction of the turning blades and other moving parts. The more efficient a device is, the greater the percentage of usable energy it produces. Appliances with an ""Energy Star"" label like the one in Figure 17.17 use energy efficiently and thereby reduce energy use. "
the energy of moving electrons is called chemical energy.,(A) true (B) false,B,"All of the examples of potential energy described above involve movement or the potential to move. The form of energy that involves movement is called mechanical energy. Other forms of energy also involve potential energy, including chemical energy and nuclear energy. Chemical energy is stored in the bonds between the atoms of compounds. For example, food and batteries both contain chemical energy. Nuclear energy is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. Nuclei of radioactive elements such as uranium are unstable, so they break apart and release the stored energy. "
electromagnetic energy includes,(A) light energy (B) sound energy (C) heat energy (D) two of the above,A,"Energy that the sun and other stars release into space is called electromagnetic energy. This form of energy travels through space as electrical and magnetic waves. Electromagnetic energy is commonly called light. It includes visible light, as well as radio waves, microwaves, and X rays (Figure 17.14). "
energy that travels in waves through matter is,(A) nuclear energy (B) electrical energy (C) sound energy (D) two of the above,C,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
the pitch of sound depends on the amplitude of sound waves.,(A) true (B) false,B,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
"compared to a higher-pitched sound, a lower-pitched sound always has a",(A) shorter wavelength (B) smaller amplitude (C) lower frequency (D) two of the above,C,"How high or low a sound seems to a listener is its pitch. Pitch, in turn, depends on the frequency of sound waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. High-pitched sounds, like the sounds of the piccolo in the Figure 1.1, have high-frequency waves. Low-pitched sounds, like the sounds of the tuba Figure 1.1, have low-frequency waves. "
the frequency of sound waves is measured in,(A) meters (B) meters/second (C) hertz (D) none of the above,C,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
dogs can hear sounds that are too high in pitch for humans to hear.,(A) true (B) false,A,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
what is the highest-frequency sound that humans normally can hear?,(A) 20 Hz (B) 200 Hz (C) 2000 Hz (D) 20 (E) 000 Hz,D,"The frequency of sound waves is measured in hertz (Hz), or the number of waves that pass a fixed point in a second. Human beings can normally hear sounds with a frequency between about 20 Hz and 20,000 Hz. Sounds with frequencies below 20 hertz are called infrasound. Infrasound is too low-pitched for humans to hear. Sounds with frequencies above 20,000 hertz are called ultrasound. Ultrasound is too high-pitched for humans to hear. Some other animals can hear sounds in the ultrasound range. For example, dogs can hear sounds with frequencies as high as 50,000 Hz. You may have seen special whistles that dogsbut not peoplecan hear. The whistles produce sounds with frequencies too high for the human ear to detect. Other animals can hear even higher-frequency sounds. Bats, like the one pictured in the Figure 1.2, can hear sounds with frequencies higher than 100,000 Hz! Q: Bats use ultrasound to navigate in the dark. Can you explain how? A: Bats send out ultrasound waves, which reflect back from objects ahead of them. They sense the reflected sound waves and use the information to detect objects they cant see in the dark. This is how they avoid flying into walls and trees and also how they find flying insects to eat. "
only rough surfaces have friction between them.,(A) true (B) false,B,"Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier objects also have more friction. Can you explain why? A: Heavier objects press together with greater force, and this causes greater friction between them. Did you ever try to furniture across the floor? Its harder to overcome friction between a heavier piece of furniture and the floor than between lighter pieces and the floor. "
factors that affect friction between two surface include the,(A) smoothness of the two surfaces (B) area of the two surfaces (C) amount of force pressing the two surfaces together (D) all of the above,D,"Friction occurs because no surface is perfectly smooth. Even surfaces that look smooth to the unaided eye appear rough or bumpy when viewed under a microscope. Look at the metal surfaces in Figure 13.8. The metal foil is so smooth that it is shiny. However, when highly magnified, the surface of metal appears to be very bumpy. All those mountains and valleys catch and grab the mountains and valleys of any other surface that contacts the metal. This creates friction. "
heavier objects have less friction with the floor than lighter objects.,(A) true (B) false,B,"Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. You cant slide as far across ice with shoes as you can on the blades of skates (see Figure 1.4). The rougher surface of the soles of the shoes causes more friction and slows you down. Q: Heavier objects also have more friction. Can you explain why? A: Heavier objects press together with greater force, and this causes greater friction between them. Did you ever try to furniture across the floor? Its harder to overcome friction between a heavier piece of furniture and the floor than between lighter pieces and the floor. "
the blades of your skates slide more easily over ice than do the soles of your shoes because the skate blades,(A) exert less force on the ice (B) make you weigh less on the ice (C) have less surface area in contact with the ice (D) none of the above,C,Rougher surfaces have more friction between them than smoother surfaces. Thats why we put sand on icy sidewalks and roads. The blades of skates are much smoother than the soles of shoes. Thats why you cant slide as far across ice with shoes as you can with skates (see Figure 13.9). The rougher surface of shoes causes more friction and slows you down. Heavier objects also have more friction because they press together with greater force. Did you ever try to push boxes or furniture across the floor? Its harder to overcome friction between heavier objects and the floor than it is between lighter objects and the floor. 
friction produces heat because it causes molecules to move faster and have more energy.,(A) true (B) false,A,"You know that friction produces heat. Thats why rubbing your hands together makes them warmer. But do you know why the rubbing produces heat? Friction causes the molecules on rubbing surfaces to move faster, so they have more heat energy. Heat from friction can be useful. It not only warms your hands. It also lets you light a match (see Figure 13.10). On the other hand, heat from friction can be a problem inside a car engine. It can cause the car to overheat. To reduce friction, oil is added to the engine. Oil coats the surfaces of moving parts and makes them slippery so there is less friction. "
engine oil reduces friction between the moving parts in a car engine by,(A) cooling the engine (B) reducing the forces on the parts (C) making the parts slippery (D) two of the above,C,"Friction is a force that opposes motion between any surfaces that are touching. All machines have moving parts and friction, so they have to use some of the work that is applied to them to overcome friction. This makes all machines less than 100 percent efficient. Because compound machines have more moving parts than simple machines, they generally have more friction to overcome. As a result, compound machines tend to have lower efficiency than simple machines. When a compound machine consists of many simple machines, friction can become a serious problem, and it may produce a lot of heat. Lubricants such as oil or grease may be used to coat the moving parts of a machine so they slide over each other more easily. This is how friction is reduced in a car engine. "
which fundamental particle was discovered first?,(A) gluon (B) photon (C) quark (D) electron,D,"Scientists have long wanted to find the most basic building blocks of the universe. They asked, what are the fundamental particles of matter that cannot be subdivided into smaller, simpler particles, and what holds these particles together? The quest for fundamental particles began thousands of years ago. Scientists thought they had finally found them when John Dalton discovered the atom in 1803 (see the timeline in Table 1.1). The word atom means indivisible, and Dalton thought that the atom could not be divided into smaller, simpler particles. Year Discovery Year 1803 Discovery John Dalton discovers the atom. 1897 J.J. Thomson discovers the electron, the first lepton to be discovered. 1905 Albert Einstein discovers the photon, the first boson to be discovered. 1911 Ernest Rutherford discovers the proton, the first particle to be discovered in the nucleus of the atom. Year 1932 Discovery James Chadwick discovers the neutron, another particle in the nucleus. 1964 Murray Gell-Mann proposes the existence of quarks, the fundamental particles that make up protons and neutrons. 1964-present Through the research of many scientists, many other fundamental particles (except gravitons) are shown to exist. For almost 100 years after Dalton discovered atoms, they were accepted as the fundamental particles of matter. But starting in the late 1890s with the discovery of electrons, particles smaller and simpler than atoms were identified. Within a few decades, protons and neutrons were also discovered. Ultimately, hundreds of subatomic particles were found. "
fundamental particles that make up protons and neutrons are known as,(A) bosons (B) leptons (C) quarks (D) none of the above,C,"Protons are made of fundamental particles called quarks and gluons. As you can see in the Figure 1.1, a proton contains three quarks (colored circles) and three streams of gluons (wavy white lines). Two of the quarks are called up quarks (u), and the third quark is called a down quark (d). The gluons carry the strong nuclear force between quarks, binding them together. This force is needed to overcome the electric force of repulsion between positive protons. Although protons were discovered almost 100 years ago, the quarks and gluons inside them were discovered much more recently. Scientists are still learning more about these fundamental particles. "
scientists think that leptons and quarks are held together by neutrinos.,(A) true (B) false,B,"Based on their knowledge of subatomic particles, scientists have developed a theory called the standard model to explain all the matter in the universe and how it is held together. The model includes only the fundamental particles in the Table 1.2. No other particles are needed to explain all kinds of matter. According to the model, all known matter consists of quarks and leptons that interact by exchanging bosons, which transmit fundamental forces. The standard model is a good theory because all of its predictions have been verified by experimental data. However, the model doesnt explain everything, including the force of gravity and why matter has mass. Scientists continue to search for evidence that will allow them to explain these aspects of force and matter as well. "
"in ordinary matter, virtually all quarks are strange quarks and charm quarks.",(A) true (B) false,B,Remember the quarks from the first page of this chapter? Quarks are even tinier particles of matter that make up protons and neutrons. There are three quarks in each proton and three quarks in each neutron. The charges of quarks are balanced exactly right to give a positive charge to a proton and a neutral charge to a neutron. It might seem strange that quarks are never found alone but only as components of other particles. This is because the quarks are held together by very strange particles called gluons. 
fundamental forces that affect matter include,(A) gravitational force (B) electromagnetic force (C) weak nuclear force (D) all of the above,D,"The interactions of matter particles are subject to four fundamental forces: gravity, electromagnetic force, weak nuclear force, and strong nuclear force. All of these forces are thought to be transmitted by bosons, the force- carrying fundamental particles. The different types of bosons and the forces they carry are shown in Table 1.2. Consider the examples of gluons, the bosons that carry the strong nuclear force. A continuous exchange of gluons between quarks binds them together in both protons and neutrons. Note that force-carrying particles for gravity (gravitons) have not yet been found. Type of Bosons Gluons Fundamental Force They Carry strong nuclear force Particles They Affect quarks Distance over Which They Carry Force only within the nucleus Type of Bosons W bosons Z bosons Photons Gravitons (hypothetical) Fundamental Force They Carry weak nuclear force Particles They Affect leptons and quarks Distance over Which They Carry Force only within the nucleus electromagnetic force force of gravity leptons and quarks leptons and quarks all distances all distances Q: Which type of boson carries force between the negative electrons and positive protons of an atom? A: Photons carry electromagnetic force. They are responsible for the force of attraction or repulsion between all electrically charged matter, including the force of attraction between negative electrons and positive protons in an atom. Q: Gravitons have not yet been discovered so they have only been hypothesized to exist. What evidence do you think leads scientists to think that these hypothetical particles affect both leptons and quarks and that they carry force over all distances? A: Gravity is known to affect all matter that has mass, and both quarks and leptons have mass. Gravity is also known to work over long as well as short distances. For example, Earths gravity keeps you firmly planted on the ground and also keeps the moon orbiting around the planet. "
gamma rays,(A) are waves of electric and magnetic energy (B) travel at the speed of light (C) have more energy than any other electromagnetic waves (D) all of the above,D,Gamma rays are the most dangerous type of radiation. They can travel farther and penetrate materials more deeply than can the charged particles emitted during alpha and beta decay. Gamma rays can be stopped only by several centimeters of lead or several meters of concrete. Its no surprise that they can penetrate and damage cells deep inside the body. 
radioactive nuclei undergo decay because they are unstable.,(A) true (B) false,A,"Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radioactive decay is a nuclearrather than chemicalreaction because it involves only the nuclei of atoms. In a nuclear reaction, one element may change into another. Click image to the left or use the URL below. URL: "
"in gamma decay, both particles of matter and energy are emitted.",(A) true (B) false,B,"In alpha and beta decay, both particles and energy are emitted. In gamma decay, only energy is emitted. Gamma decay occurs when an unstable nucleus gives off gamma rays. Gamma rays, like rays of visible light and X-rays, are waves of energy that travel through space at the speed of light. Gamma rays have the greatest amount of energy of all such waves. By itself, gamma decay doesnt cause one element to change into another, but it is released in nuclear reactions that do. Some of the energy released in alpha and beta decay is in the form of gamma rays. You can learn more about gamma radiation at this URL:  (2:45). MEDIA Click image to the left or use the URL below. URL: "
gamma decay results in a nucleus with a different number of protons.,(A) true (B) false,B,"Both alpha and beta decay change the number of protons in an atoms nucleus, thereby changing the atom to a different element. In alpha decay, the nucleus loses two protons. In beta decay, the nucleus either loses a proton or gains a proton. In gamma decay, no change in proton number occurs, so the atom does not become a different element. Q: If the radioactive element polonium (Po) undergoes alpha decay, what element does it become? A: From the periodic table, the atomic number of polonium is 84, so it has 84 protons. If it loses two protons through alpha decay, it will have 82 protons. Atoms with 82 protons are the element lead (Pb). "
higher-energy electromagnetic waves have lower frequencies.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed across space, they may differ in their wavelengths, frequencies, and energy levels. Wavelength is the distance between corresponding points of adjacent waves (see the Figure 1.1). Wavelengths of electromagnetic waves range from longer than a soccer field to shorter than the diameter of an atom. Wave frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second. The energy of electromagnetic waves depends on their frequency. Low-frequency waves have little energy and are normally harmless. High-frequency waves have a lot of energy and are potentially very harmful. Q: Which electromagnetic waves do you think have higher frequencies: visible light or X rays? A: X rays are harmful but visible light is harmless, so you can infer that X rays have higher frequencies than visible light. "
gamma rays have wavelengths shorter than the nucleus of an atom.,(A) true (B) false,A,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
the frequencies of gamma rays are,(A) higher than 1019 hertz (B) lower than a billion waves per second (C) higher than the frequencies of X rays (D) two of the above,D,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
sources of gamma rays include,(A) the sun (B) collapsing stars (C) radioactive decay (D) all of the above,D,"Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect living things on Earth if they werent absorbed by the atmosphere. A: Gamma rays would destroy most living things on Earth because they have so much energy. "
gamma rays from space are absorbed by earths atmosphere.,(A) true (B) false,A,"Gamma rays are given off by radioactive atoms and nuclear explosions. They are also given off by the sun and other stars, as well as by collapsing stars in gamma ray bursts. Fortunately, gamma rays from space are absorbed by Earths atmosphere before they can reach the surface. Q: Predict how gamma rays might affect living things on Earth if they werent absorbed by the atmosphere. A: Gamma rays would destroy most living things on Earth because they have so much energy. "
gamma rays can pass through,(A) bones (B) teeth (C) skin (D) all of the above,D,"The extremely high energy of gamma rays allows them to penetrate just about anything. They can even pass through bones and teeth. This makes gamma rays very dangerous. They can destroy living cells, produce gene mutations, and cause cancer. Ironically, the deadly effects of gamma rays can be used to treat cancer. In this type of treatment, a medical device sends out focused gamma rays that target cancerous cells. The gamma rays kill the cells and destroy the cancer. "
gravity acts only between objects that are touching.,(A) true (B) false,B,"Gravity has traditionally been defined as a force of attraction between things that have mass. According to this conception of gravity, anything that has mass, no matter how small, exerts gravity on other matter. Gravity can act between objects that are not even touching. In fact, gravity can act over very long distances. However, the farther two objects are from each other, the weaker is the force of gravity between them. Less massive objects also have less gravity than more massive objects. "
the strength of gravity between two objects depends on their,(A) size (B) volume (C) mass (D) all of the above,C,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
which of the following objects has the greatest gravity?,(A) the moon (B) the sun (C) Earth (D) you,B,"Newtons law also states that the strength of gravity between any two objects depends on two factors: the masses of the objects and the distance between them. Objects with greater mass have a stronger force of gravity between them. For example, because Earth is so massive, it attracts you and your desk more strongly that you and your desk attract each other. Thats why you and the desk remain in place on the floor rather than moving toward one another. Objects that are closer together have a stronger force of gravity between them. For example, the moon is closer to Earth than it is to the more massive sun, so the force of gravity is greater between the moon and Earth than between the moon and the sun. Thats why the moon circles around Earth rather than the sun. You can see this in the Figure 1.1. "
there is gravitational attraction between you and every object around you.,(A) true (B) false,A,"You are already very familiar with Earths gravity. It constantly pulls you toward the center of the planet. It prevents you and everything else on Earth from being flung out into space as the planet spins on its axis. It also pulls objects above the surface, from meteors to skydivers, down to the ground. Gravity between Earth and the moon and between Earth and artificial satellites keeps all these objects circling around Earth. Gravity also keeps Earth moving around the sun. "
weight is measured with a balance.,(A) true (B) false,B,"Weight measures the force of gravity pulling on an object. Because weight measures force, the SI unit for weight is the newton (N). On Earth, a mass of 1 kilogram has a weight of about 10 newtons because of the pull of Earths gravity On the moon, which has less gravity, the same mass would weigh less. Weight is measured with a scale, like the spring scale in Figure 13.16. The scale measures the force with which gravity pulls an object downward. "
the groups in question 1 are the only groups in the periodic that contain elements in more than one class.,(A) true (B) false,A,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
metalloids include the element,(A) gallium (B) phosphorus (C) selenium (D) germanium,D,"Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between metals and nonmetals in terms of their properties. Q: How does the position of an element in the periodic table influence its properties? A: Elements are arranged in the periodic table by their atomic number, which is the number of protons in their atoms. Atoms are neutral in electric charge, so they always have the same number of electrons as protons. It is the number of electrons in the outer energy level of atoms that determines most of the properties of elements. "
which of the following is a property of metalloids?,(A) malleability (B) brittleness (C) dullness (D) all of the above,B,"Most metalloids have some physical properties of metals and some physical properties of nonmetals. For example, metals are good conductors of both heat and electricity, whereas nonmetals generally cannot conduct heat or electricity. And metalloids? They fall between metals and nonmetals in their ability to conduct heat, and if they can conduct electricity, they usually can do so only at higher temperatures. Metalloids that can conduct electricity at higher temperatures are called semiconductors. Silicon is an example of a semiconductor. It is used to make the tiny electric circuits in computer chips. You can see a sample of silicon and a silicon chip in the Figure 1.2. Metalloids tend to be shiny like metals but brittle like nonmetals. Because they are brittle, they may chip like glass or crumble to a powder if struck. Other physical properties of metalloids are more variable, including their boiling and melting points, although all metalloids exist as solids at room temperature. Click image to the left or use the URL below. URL: "
which of the following statements is (are) true of boron?,(A) It has three valence electrons (B) It is fairly reactive (C) It is a solid at room temperature (D) all of the above,D,"Group 13 of the periodic table is also called the boron group because boron (B) is the first element at the top of the group (see Figure 1.2). Boron is also the only metalloid in this group. The other four elements in the groupaluminum (Al), gallium (Ga), indium (In), and thallium (Tl)are all metals. Group 13 elements have three valence electrons and are fairly reactive. All of them are solids at room temperature. "
carbon is a metalloid.,(A) true (B) false,B,"Carbon is a nonmetal in group 14 of the periodic table. Like other group 14 compounds, carbon has four valence electrons. Valence electrons are the electrons in the outer energy level of an atom that are involved in chemical bonds. The valence electrons of carbon are shown in Figure 9.1. "
all group 15 elements are very reactive.,(A) true (B) false,B,"The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are eager to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table. Alkali metals have just one valence electron, which they are equally eager to donate. Reactions involving halogens, especially halogens near the top of the group, may be explosive. You can see some examples in the video below. (Warning: Dont try any of these reactions at home!) Click image to the left or use the URL below. URL: "
which of the following elements is not a halogen?,(A) bromine (B) chlorine (C) selenium (D) iodine,C,"Halogens are highly reactive nonmetallic elements in group 17 of the periodic table. As you can see in the periodic table 1.1, the halogens include the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). All of them are relatively common on Earth except for astatine. Astatine is radioactive and rapidly decays to other, more stable elements. As a result, it is one of the least common elements on Earth. Q: Based on their position in the periodic table from the Figure 1.1, how many valence electrons do you think halogens have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the periodic table above.) Therefore, halogens have seven valence electrons. "
the halogen named astatine is radioactive.,(A) true (B) false,A,"Halogens are highly reactive nonmetallic elements in group 17 of the periodic table. As you can see in the periodic table 1.1, the halogens include the elements fluorine (F), chlorine (Cl), bromine (Br), iodine (I), and astatine (At). All of them are relatively common on Earth except for astatine. Astatine is radioactive and rapidly decays to other, more stable elements. As a result, it is one of the least common elements on Earth. Q: Based on their position in the periodic table from the Figure 1.1, how many valence electrons do you think halogens have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the periodic table above.) Therefore, halogens have seven valence electrons. "
halogens tend to form compounds with elements in group,(A) 1 (B) 2 (C) 16 (D) 18,A,"Elements in group 17 are called halogens (see Figure 6.13). They are highly reactive nonmetals with seven valence electrons. The halogens react violently with alkali metals, which have one valence electron. The two elements combine to form a salt. For example, the halogen chlorine (Cl) and the alkali metal sodium (Na) react to form table salt, or sodium chloride (NaCl). The halogen group includes gases, liquids, and solids. For example, chlorine is a gas at room temperature, bromine (Br) is a liquid, and iodine (I) is a solid. You can watch a video demonstrating the reactivity of halogens at this URL:  . "
all halogens are gases at room temperature.,(A) true (B) false,B,"The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine is red, and iodine and astatine are nearly black. Like other nonmetals, halogens cannot conduct electricity or heat. Compared with most other elements, halogens have relatively low melting and boiling points. "
properties of halogens include,(A) relatively low melting point (B) ability to conduct electricity (C) ability to conduct heat (D) all of the above,A,"The halogen group is quite diverse. It includes elements that occur in three different states of matter at room temperature. Fluorine and chlorine are gases, bromine is a liquid, and iodine and astatine are solids. Halogens also vary in color, as you can see in the Figure 1.2. Fluorine and chlorine are green, bromine is red, and iodine and astatine are nearly black. Like other nonmetals, halogens cannot conduct electricity or heat. Compared with most other elements, halogens have relatively low melting and boiling points. "
functions of the ear include,(A) gathering sound waves (B) amplifying sound waves (C) changing sound waves to electrical signals (D) all of the above,A,"The ear is a complex organ that senses sound energy so we can hear. Hearing is the ability to sense sound energy and perceive sound. All of the structures of the ear that are involved in hearing must work well for a person to have normal hearing. Damage to any of the structures, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. "
all of the following are parts of the outer ear except the,(A) pinna (B) ear canal (C) oval window (D) eardrum,C,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
the main role of the middle ear is to change sound waves to electrical impulses.,(A) true (B) false,B,"The stirrup in the middle ear passes the amplified sound waves to the inner ear through the oval window. When the oval window vibrates, it causes the cochlea to vibrate as well. The cochlea is a shell-like structure that is full of fluid and lined with nerve cells called hair cells. Each hair cell has many tiny hairs, as you can see in the magnified image 1.2. When the cochlea vibrates, it causes waves in the fluid inside. The waves bend the hairs on the hair cells, and this triggers electrical impulses. The electrical impulses travel to the brain through nerves. Only after the nerve impulses reach the brain do we hear the sound. "
the inner ear includes the,(A) stirrup (B) cochlea (C) anvil (D) all of the above,B,"The outer ear includes the pinna, ear canal, and eardrum. The pinna is the only part of the ear that extends outward from the head. Its position and shape make it good at catching sound waves and funneling them into the ear canal. The ear canal is a tube that carries sound waves into the ear. The sound waves travel through the air inside the ear canal to the eardrum. The eardrum is like the head of a drum. Its a thin membrane stretched tight across the end of the ear canal. The eardrum vibrates when sound waves strike it, and it sends the vibrations on to the middle ear. "
you perceive a sound as soon as the sound waves strike your eardrum.,(A) true (B) false,B,"Hearing is the ability to sense sound. Sound travels through the air in waves, much like the waves you see in the water pictured below ( Figure 1.1). Sound waves in air cause vibrations inside the ears. The ears sense the vibrations. The human ear is pictured below ( Figure 1.2). As you read about it, trace the path of sound waves through the ear. Assume a car horn blows in the distance. Sound waves spread through the air from the horn. Some of the sound waves reach your ear. The steps below show what happens next. They explain how your ears sense the sound. 1. The sound waves travel to the ear canal (external auditory canal in the figure). This is a tube-shaped opening in the ear. Sound waves travel through the air in all directions away from a sound, like waves traveling through water away from where a pebble was dropped. Read the names of the parts of the ear in the text; then find each of the parts in the diagram. Note that the round window is distinct from the oval window. 2. At the end of the ear canal, the sound waves hit the eardrum (tympanic membrane). This is a thin membrane that vibrates like the head of a drum when sound waves hit it. 3. The vibrations pass from the eardrum to the hammer (malleus). This is the first of three tiny bones that pass vibrations through the ear. 4. The hammer passes the vibrations to the anvil (incus), the second tiny bone that passes vibrations through the ear. 5. The anvil passes the vibrations to the stirrup (stapes), the third tiny bone that passes vibrations through the ear. 6. From the stirrup, the vibrations pass to the oval window. This is another membrane like the eardrum. 7. The oval window passes the vibrations to the cochlea. The cochlea is filled with liquid that moves when the vibrations pass through, like the waves in water when you drop a pebble into a pond. Tiny hair cells line the cochlea and bend when the liquid moves. When the hair cells bend, they release neurotransmitters. 8. The neurotransmitters trigger nerve impulses that travel to the brain through the auditory nerve (cochlear No doubt youve been warned that listening to loud music or other loud sounds can damage your hearing. Its true. In fact, repeated exposure to loud sounds is the most common cause of hearing loss. The reason? Very loud sounds can kill the tiny hair cells lining the cochlea. The hair cells do not generally grow back once they are destroyed, so this type of hearing loss is permanent. You can protect your hearing by avoiding loud sounds or wearing earplugs or other ear protectors. "
the most common cause of hearing loss is,(A) loud sounds (B) infections (C) injuries (D) none of the above,A,"All these structures of the ear must work well for normal hearing. Damage to any of them, through illness or injury, may cause hearing loss. Total hearing loss is called deafness. To learn more about hearing loss, watch the animation at this URL:  (1:39). MEDIA Click image to the left or use the URL below. URL:  Most adults experience at least some hearing loss as they get older. The most common cause is exposure to loud sounds, which damage hair cells. The louder a sound is, the less exposure is needed for damage to occur. Even a single brief exposure to a sound louder than 115 decibels can cause hearing loss. Figure 20.9 shows the relationship between loudness, exposure time, and hearing loss. "
loud sounds cause loss of hearing by damaging the tiny bones of the middle ear.,(A) true (B) false,B,"Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. "
louder sounds damage hearing more quickly than softer sounds.,(A) true (B) false,A,"The most common cause of hearing loss is exposure to loud sounds. Loud sounds can damage hair cells inside the ears. Hair cells change sound waves to electrical signals that the brain can interpret as sounds. Louder sounds, which have greater intensity than softer sounds, can damage hair cells more quickly than softer sounds. You can see the relationship between sound intensity, exposure time, and hearing loss in the following Figure 1.1. The intensity of sounds is measured in decibels (dB). Q: What is the maximum amount of time you should be exposed to a sound as intense as 100 dB? What might make a sound this intense? A: You should be exposed to a 100-dB sound for no longer than 15 minutes. An example of a sound this intense is the sound of a car horn. "
hearing loss caused by loud sounds is temporary.,(A) true (B) false,B,"Hearing loss caused by loud sounds is permanent. However, this type of hearing loss can be prevented by protecting the ears from loud sounds. "
the permissible exposure time to a 97-decibel sound is,(A) 1 minute (B) 4 minutes (C) 30 minutes (D) 4 hours,C,"The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. Q: How much louder than a 20-decibel whisper is the 60-decibel sound of a vacuum cleaner? A: The vacuum cleaner is 10,000 times louder than the whisper! "
heat is a form of energy.,(A) true (B) false,B,"Heat and light are forms of energy. Other forms are chemical and electrical energy. Energy cant be created or destroyed. It can change form. For example, a piece of wood has chemical energy stored in its molecules. When the wood burns, the chemical energy changes to heat and light energy. "
temperature measures the average kinetic energy of particles.,(A) true (B) false,A,"No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. With a higher temperature, matter feels warmer. When particles move more slowly, they have less kinetic energy on average, so their temperature is lower. With a lower temperature, matter feels cooler. "
thermal energy always moves from cooler to warmer substances.,(A) true (B) false,B,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
thermal energy is transferred between two substances until,(A) one substance is warmer than the other (B) both substances are warmer than they were (C) both substances are cooler than they were (D) both substances have the same temperature,D,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
thermal energy is transferred between substances only when they have different,(A) masses (B) volumes (C) temperatures (D) two of the above,C,"Heat is the transfer of thermal energy between substances. Thermal energy is the kinetic energy of moving particles of matter, measured by their temperature. Thermal energy always moves from matter with greater thermal energy to matter with less thermal energy, so it moves from warmer to cooler substances. You can see this in the Figure particles of the cooler substance. Thermal energy is transferred in this way until both substances have the same thermal energy and temperature. Q: How is thermal energy transferred in an oven? A: Thermal energy of the hot oven is transferred to the cooler food, raising its temperature. "
thermal energy can be transferred by,(A) conduction (B) convection (C) radiation (D) all of the above,D,"The bonfire from the opening image has a lot of thermal energy. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Thermal energy from the bonfire is transferred to the hands by thermal radiation. Thermal radiation is the transfer of thermal energy by waves that can travel through air or even through empty space, as shown in the Figure 1.1. When the waves of thermal energy reach objects, they transfer the energy to the objects, causing them to warm up. This is how the fire warms the hands of someone sitting near the bonfire. This is also how the suns energy reaches Earth and heats its surface. Without the energy radiated from the sun, Earth would be too cold to support life as we know it. Thermal radiation is one of three ways that thermal energy can be transferred. The other two ways are conduction and convection, both of which need matter to transfer energy. Radiation is the only way of transferring thermal energy that doesnt require matter. "
thermal energy is always transferred,(A) from a cooler to warmer object (B) from a warmer to cooler object (C) between objects that are the same temperature (D) two of the above,B,"The bonfire from the opening image has a lot of thermal energy. Thermal energy is the total kinetic energy of moving particles of matter, and the transfer of thermal energy is called heat. Thermal energy from the bonfire is transferred to the hands by thermal radiation. Thermal radiation is the transfer of thermal energy by waves that can travel through air or even through empty space, as shown in the Figure 1.1. When the waves of thermal energy reach objects, they transfer the energy to the objects, causing them to warm up. This is how the fire warms the hands of someone sitting near the bonfire. This is also how the suns energy reaches Earth and heats its surface. Without the energy radiated from the sun, Earth would be too cold to support life as we know it. Thermal radiation is one of three ways that thermal energy can be transferred. The other two ways are conduction and convection, both of which need matter to transfer energy. Radiation is the only way of transferring thermal energy that doesnt require matter. "
only the particles of warm matter are in constant random motion.,(A) true (B) false,B,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
all of the following are examples of heat conduction except,(A) pressing a shirt with a hot iron (B) warming your hands by holding a cup of hot chocolate (C) warming your hands over a campfire (D) heating soup in a pan on a stovetop,C,"The cookie sheet in the opening image transfers thermal energy to the cookies and helps them bake. There are many other common examples of conduction. The Figure 1.1 shows a few situations in which thermal energy is transferred in this way. Q: How is thermal energy transferred in each of the situations pictured in the Figure 1.1? A: Thermal energy is transferred by conduction from the hot iron to the shirt, from the hot cup to the hand holding it, from the flame of the camp stove to the bottom of the pot as well as from the bottom of the pot to the food inside, and from the feet to the snow. The shirt, hand, pot, food, and snow become warmer because of the transferred energy. Because the feet lose thermal energy, they feel colder. "
"if you hold an ice cube in your hand, your hand feels really cold because",(A) cold is transferred to your hand from the ice cube (B) thermal energy is transferred from your hand to the ice cube (C) thermal energy is transferred to your hand from the ice cube (D) none of the above,B,Think about how you would make ice cubes in a tray. First you would fill the tray with water from a tap. Then you would place the tray in the freezer compartment of a refrigerator. The freezer is very cold. What happens next? 
conduction occurs when particles of matter collide.,(A) true (B) false,A,"To understand how conduction works, you need to think about the tiny particles that make up matter. The particles of all matter are in constant random motion, but the particles of warmer matter have more energy and move more quickly than the particles of cooler matter. When particles of warmer matter collide with particles of cooler matter, they transfer some of their thermal energy to the cooler particles. From particle to particle, like dominoes falling, thermal energy moves through matter. In the opening photo above, conduction occurs between particles of metal in the cookie sheet and anything cooler that comes into contact with ithopefully, not someones bare hands! "
a hot-water heating system includes,(A) ducts (B) pipes (C) registers (D) two of the above,B,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
"in a hot-water heating system, hot water transfers thermal energy to radiators by thermal radiation.",(A) true (B) false,B,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
"in both hot-water and warm-air heating systems, thermal energy is transferred through the air in each room by conduction.",(A) true (B) false,B,"A hot-water heating system uses thermal energy to heat water and then pumps the hot water throughout the building in a system of pipes and radiators. You can see a diagram of this type of heating system in Figure 18.12. Typically, the water is heated in a boiler that burns natural gas or heating oil. There is usually a radiator in each room that gets warm when the hot water flows through it. The radiator transfers thermal energy to the air around it by conduction and radiation. The warm air then circulates throughout the room in convection currents. The hot water cools as it flows through the system and transfers its thermal energy. When it finally returns to the boiler, it is heated again and the cycle repeats. "
a warm-air heating system includes,(A) ducts (B) pipes (C) registers (D) two of the above,D,"A warm-air heating system uses thermal energy to heat air. It then forces the warm air through a system of ducts. You can see a diagram of this type of heating system in Figure 18.13. Typically, the air is heated in a furnace that burns natural gas or heating oil. When the air is warm, a fan blows it through the ducts and out through vents that are located in each room. Warm air blowing out of a vent moves across the room, pushing cold air out of the way. The cold air enters an intake vent on the opposite side of the room and returns to the furnace with the help of another fan. In the furnace, the cold air is heated, and the cycle repeats. "
hydrocarbons are the simplest type of carbon compounds.,(A) true (B) false,A,"Hydrocarbons are compounds that contain only carbon and hydrogen. Hydrocarbons are the simplest type of carbon-based compounds. Nonetheless, they can vary greatly in size. The smallest hydrocarbons have just one or two carbon atoms, but large hydrocarbons may have hundreds. The size of hydrocarbon molecules influences their properties. For example, it influences their boiling and melting points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar and do not dissolve in water. In fact, they tend to repel water. Thats why they are used in floor wax and similar products. Hydrocarbons can be classified in two basic classes. The classes are saturated hydrocarbons and unsaturated hydrocarbons. This classification is based on the number of bonds between carbon atoms. You can learn more about both types of hydrocarbons at this URL:  (6:41). MEDIA Click image to the left or use the URL below. URL: "
hydrocarbon molecules,(A) are polar (B) do not dissolve in water (C) are all liquids at room temperature (D) two of the above,B,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
hydrocarbons are used to make,(A) fuels (B) waxes (C) fabrics (D) all of the above,D,"It is hard to overstate the importance of hydrocarbons to modern life. Hydrocarbons have even been called the driving force of western civilization. You saw some ways they are used in the opening image. Several other ways are pictured in the Figure 1.1. The most important use of hydrocarbons is for fuel. Gasoline, natural gas, fuel oil, diesel fuel, jet fuel, coal, kerosene, and propane are just some of the commonly used hydrocarbon fuels. Hydrocarbons are also used to make things, including plastics and synthetic fabrics such as polyester. Motor oil: Motor oil consists of several hydrocarbons. It lubricates the moving parts of car engines. Asphalt: Asphalt pavement on highways is made of hy- drocarbons found in petroleum. Candle: Many candles are made of paraffin wax, a solid mixture of hydrocarbons. Lighter: This lighter burns the hydrocarbon named butane. Rain Boots: These rain boots are made of a mixture of several hydro- carbons. Transportation: These forms of transportation are fueled by different mixtures of hydrocarbons. "
the size of hydrocarbon molecules influences their melting and boiling points.,(A) true (B) false,A,"The size of hydrocarbon molecules influences their properties, including their melting and boiling points. As a result, some hydrocarbons are gases at room temperature, while others are liquids or solids. Hydrocarbons are generally nonpolar, which means that their molecules do not have oppositely charged sides. Therefore, they do not dissolve in water, which is a polar compound. In fact, hydrocarbons tend to repel water. Thats why they are used in floor wax and similar products. "
hydrocarbons consist only of carbon and hydrogen atoms.,(A) true (B) false,A,"Hydrocarbons are compounds that contain only carbon and hydrogen atoms. The smallest hydrocarbon, methane (CH4 ), contains just one carbon atom and four hydrogen atoms. Larger hydrocarbons contain many more. Hydro- carbons with four or more carbon atoms can have different shapes. Although they have the same chemical formula, with the same numbers of carbon and hydrogen atoms, they form different compounds, called isomers. Isomers are compounds whose properties are different because their atoms are bonded together in different arrangements. "
saturated hydrocarbons,(A) contain only single bonds between carbon atoms (B) contain as many hydrogen atoms as possible (C) are called alkanes (D) all of the above,D,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
what is the general formula for a saturated hydrocarbon?,(A) CnH2n+2 (B) CnH2n (C) CnH2n-2 (D) none of the above,A,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
elements in group 1 of the periodic table include,(A) sodium (B) hydrogen (C) calcium (D) two of the above,D,"Sodium (Na) is an element in group 1 of the periodic table of the elements. This group (column) of the table is shown in Figure below. It includes the nonmetal hydrogen (H) and six metals that are called alkali metals. Elements in the same group of the periodic table have the same number of valence electrons. These are the electrons in their outer energy level that can be involved in chemical reactions. Valence electrons determine many of the properties of an element, so elements in the same group have similar properties. All the elements in group 1 have just one valence electron. This makes them very reactive. Q: Why does having just one valence electron make group 1 elements very reactive? A: With just one valence electron, group 1 elements are eager to lose that electron. Doing so allows them to achieve a full outer energy level and maximum stability. "
how many valence electrons do alkali metals have?,(A) 1 (B) 2 (C) 3 (D) 4,A,"All alkaline Earth metals have similar properties because they all have two valence electrons. They readily give up their two valence electrons to achieve a full outer energy level, which is the most stable arrangement of electrons. As a result, they are very reactive, although not quite as reactive as the alkali metals in group 1. For example, alkaline Earth metals will react with cold water, but not explosively as alkali metals do. Because of their reactivity, alkaline Earth metals never exist as pure substances in nature. Instead, they are always found combined with other elements. The reactivity of alkaline Earth metals increases from the top to the bottom of the group. Thats because the atoms get bigger from the top to the bottom, so the valence electrons are farther from the nucleus. When valence electrons are farther from the nucleus, they are attracted less strongly by the nucleus and more easily removed from the atom. This makes the atom more reactive. Q: Alkali metals have just one valence electron. Why are alkaline Earth metals less reactive than alkali metals? A: It takes more energy to remove two valence electrons from an atom than one valence electron. This makes alkaline Earth metals with their two valence electrons less reactive than alkali metals with their one valence electron. "
hydrogen and alkali metals are very reactive.,(A) true (B) false,A,"Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very eager to gain an electron. Click image to the left or use the URL below. URL: "
the most reactive alkali metal is lithium.,(A) true (B) false,B,"Hydrogen is a very reactive gas, and the alkali metals are even more reactive. In fact, they are the most reactive metals and, along with the elements in group 17, are the most reactive of all elements. The reactivity of alkali metals increases from the top to the bottom of the group, so lithium (Li) is the least reactive alkali metal and francium (Fr) is the most reactive. Because alkali metals are so reactive, they are found in nature only in combination with other elements. They often combine with group 17 elements, which are very eager to gain an electron. Click image to the left or use the URL below. URL: "
characteristics of alkali metals include,(A) softness (B) high density (C) liquid state at room temperature (D) two of the above,A,"Besides being very reactive, alkali metals share a number of other properties. Alkali metals are all solids at room temperature. Alkali metals are low in density, and some of them float on water. Alkali metals are relatively soft. Some are even soft enough to cut with a knife, like the sodium pictured in the Figure 1.1. "
the alkali metal named francium is radioactive.,(A) true (B) false,A,"Although all group 1 elements share certain properties, such as being very reactive, they are not alike in every way. Three different group 1 elements are described in more detail below. Notice the ways in which they differ from one another. Q: Why do you think hydrogen gas usually exists as diatomic molecules? A: Each hydrogen atom has just one electron. When two hydrogen atoms bond together, they share a pair of electrons. The shared electrons fill their only energy level, giving them the most stable arrangement of electrons. Potassium is a soft, silvery metal that ignites explosively in water. It easily loses its one valence electron to form positive potassium ions (K+ ), which are needed by all living cells. Potassium is so impor- tant for plants that it is found in almost all fertilizers, like the one shown here. Potassium is abundant in Earths crust in minerals such as feldspar. Francium has one of the largest, heaviest atoms of all elements. Its one valence electron is far removed from the nucleus, as you can see in the atomic model on the right, so it is easily removed from the atom. Francium is radioactive and quickly decays to form other elements such as radium. This is why francium is extremely rare in nature. Less than an ounce of francium is present on Earth at any given time. Q: Francium decays too quickly to form compounds with other elements. Which elements to you think it would bond with if it could? A: With one valence electron, francium would bond with a halogen element in group 17, which has seven valence electrons and needs one more to fill its outer energy level. Elements in group 17 include fluorine and chlorine. "
water is a polar compound.,(A) true (B) false,A,"Polar compounds, such as water, are compounds that have a partial negative charge on one side of each molecule and a partial positive charge on the other side. All polar compounds contain polar bonds (although not all compounds that contain polar bonds are polar.) In a polar bond, two atoms share electrons unequally. One atom attracts the shared electrons more strongly, so it has a partial negative charge. The other atom attracts the shared electrons less strongly, so it is has a partial positive charge. In a water molecule, the oxygen atom attracts the shared electrons more strongly than the hydrogen atoms do. This explains why the oxygen side of the water molecule has a partial negative charge and the hydrogen side of the molecule has a partial positive charge. Q: If a molecule is polar, how might this affect its interactions with nearby molecules of the same compound? A: Opposite charges on different molecules of the same compound might cause the molecules to be attracted to each other. "
hydrogen bonds are very strong bonds.,(A) true (B) false,B,"Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weak as chemical bonds go. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds. Click image to the left or use the URL below. URL: "
"in water, hydrogen bonds hold together",(A) hydrogen and oxygen atoms in the same molecule (B) hydrogen and oxygen atoms in different molecules (C) hydrogen atoms in different molecules (D) hydrogen atoms in the same molecule,B,"Because of waters polarity, individual water molecules are attracted to one another. You can see this in the Figure of a nearby water molecule. This force of attraction is called a hydrogen bond. Hydrogen bonds are intermolecular (between-molecule) bonds, rather than intramolecular (within-molecule) bonds. They occur not only in water but in other polar molecules in which positive hydrogen atoms are attracted to negative atoms in nearby molecules. Hydrogen bonds are relatively weak as chemical bonds go. For example, they are much weaker than the bonds holding atoms together within molecules of covalent compounds. Click image to the left or use the URL below. URL: "
polar molecules tend to have lower boiling points than nonpolar molecules.,(A) true (B) false,B,"Changes of state from solid to liquid and from liquid to gas occur when matter gains energy. The energy allows individual molecules to separate and move apart from one another. It takes more energy to bring about these changes of state for polar molecules. Although hydrogen bonds are weak, they add to the energy needed for molecules to move apart from one another, so it takes higher temperatures for these changes of state to occur in polar compounds. This explains why polar compounds have relatively high melting and boiling points. The Table 1.1 compares melting and boiling points for some polar and nonpolar covalent compounds. Name of Compound (Chemical Formula) Methane (CH4 ) Ethylene (C2 H2 ) Ammonia (NH3 ) Water (H2 O) Polar or Nonpolar? Melting Point( C) Boiling Point ( C) nonpolar nonpolar polar polar -182 -169 -78 0 -162 -104 -33 100 Q: Which compound in the Table 1.1 do you think is more polar, ammonia or water? "
which of the following compounds has the highest melting point?,(A) methane (B) ethylene (C) ammonia (D) water,D,"The temperature at which a substance melts is called its melting point. Melting point is a physical property of matter. The gold pictured in the Figure 1.1, for example, has a melting point of 1064 C. This is a high melting point, and most other metals also have high melting points. The melting point of ice, in comparison, is much lower at 0 C. Many substances have even lower melting points. For example, the melting point of oxygen is -222 C. "
an inclined plane is one of six types of simple machines.,(A) true (B) false,A,"An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined plane. A ramp like the one in the Figure 1.1 is another example of an inclined plane. Inclined planes make it easier to move objects to a higher elevation. The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation. "
simple machines that are variations of the inclined plane include the,(A) screw (B) lever (C) wedge (D) two of the above,D,Two simple machines that are based on the inclined plane are the wedge and the screw. Both increase the force used to move an object because the input force is applied over a greater distance than the output force. 
examples of inclined planes include,(A) ramps (B) playground slides (C) ladders (D) all of the above,D,"An inclined plane is a simple machine that consists of a sloping surface connecting a lower elevation to a higher elevation. An inclined plane is one of six types of simple machines, and it is one of the oldest and most basic. In fact, two other simple machines, the wedge and the screw, are variations of the inclined plane. A ramp like the one in the Figure 1.1 is another example of an inclined plane. Inclined planes make it easier to move objects to a higher elevation. The sloping surface of the inclined plane supports part of the weight of the object as it moves up the slope. As a result, it takes less force to move the object uphill. The trade-off is that the object must be moved over a greater distance than if it were moved straight up to the higher elevation. "
mechanical advantage is the ratio of input force to output force.,(A) true (B) false,B,"How much a machine changes the input force is its mechanical advantage. Mechanical advantage is the ratio of the output force to the input force, so it can be represented by the equation: Actual Mechanical Advantage = Output force Input force Note that this equation represents the actual mechanical advantage of a machine. The actual mechanical advantage takes into account the amount of the input force that is used to overcome friction. The equation yields the factor by which the machine changes the input force when the machine is actually used in the real world. "
the mechanical advantage of an inclined plane is always,(A) less than 1 (B) equal to 1 (C) greater than 1 (D) equal to zero,C,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of output force (the force put out by the machined) to input force (the force put into the machine). For an inclined plane, less force is put into moving an object up the slope than if the object were lifted straight up, so the mechanical advantage is greater than 1. The more gradual the slope of the inclined plane, the less input force is needed and the greater the mechanical advantage. Q: Which inclined plane pictured in the Figure 1.2 has a greater mechanical advantage? A: The inclined plane on the right has a more gradual slope, so it has a greater mechanical advantage. Less force is needed to move objects up the gentler slope, yet the objects attain the same elevation as they would if more force were used to push them up the steeper slope. "
"the more gradual the slope of an inclined plane, the greater its mechanical advantage is.",(A) true (B) false,A,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of output force (the force put out by the machined) to input force (the force put into the machine). For an inclined plane, less force is put into moving an object up the slope than if the object were lifted straight up, so the mechanical advantage is greater than 1. The more gradual the slope of the inclined plane, the less input force is needed and the greater the mechanical advantage. Q: Which inclined plane pictured in the Figure 1.2 has a greater mechanical advantage? A: The inclined plane on the right has a more gradual slope, so it has a greater mechanical advantage. Less force is needed to move objects up the gentler slope, yet the objects attain the same elevation as they would if more force were used to push them up the steeper slope. "
only moving objects have inertia.,(A) true (B) false,B,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
newtons first law of motion is also called the law of inertia.,(A) true (B) false,A,"Newtons first law of motion is also called the law of inertia. Inertia is the tendency of an object to resist a change in its motion. If an object is already at rest, inertia will keep it at rest. If the object is already moving, inertia will keep it moving. Think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat. Why? The brakes stop the car but not your body, so your body keeps moving forward because of inertia. Thats why its important to always wear a seat belt. Inertia also explains the amusement park ride in Figure 14.1. The car keeps changing direction, but the riders keep moving in the same direction as before. They slide to the opposite side of the car as a result. You can see an animation of inertia at this URL: "
which object has the greatest inertia?,(A) 5-kg rock (B) 6-kg box of feathers (C) 7-kg bag of groceries (D) 8-kg bowling ball,D,"The inertia of an object depends on its mass. Objects with greater mass also have greater inertia. Think how hard it would be to push a big box full of books, like the one in Figure 14.3. Then think how easy it would be to push the box if it was empty. The full box is harder to move because it has greater mass and therefore greater inertia. "
"once an object starts moving, inertia keeps it moving without any additional force being applied to the object.",(A) true (B) false,A,"Inertia is the tendency of an object to resist a change in its motion. All objects have inertia, whether they are stationary or moving. Inertia explains Newtons first law of motion, which states that an object at rest will remain at rest and an object in motion will stay in motion unless it is acted on by an unbalanced force. Thats why Newtons first law of motion is sometimes called the law of inertia. Q: You probably dont realize it, but you experience inertia all the time, and you dont have to ride a skateboard. For example, think about what happens when you are riding in a car that stops suddenly. Your body moves forward on the seat and strains against the seat belt. Why does this happen? A: The brakes stop the car but not your body, so your body keeps moving forward because of inertia. "
intensity is a measure of a sound waves,(A) speed (B) frequency (C) wavelength (D) energy,D,"Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is determined, in turn, by the intensity of the sound waves. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). "
an 80-decibel sound is 20 times louder than a 60-decibel sound.,(A) true (B) false,B,"The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. Q: How much louder than a 20-decibel whisper is the 60-decibel sound of a vacuum cleaner? A: The vacuum cleaner is 10,000 times louder than the whisper! "
the intensity of sound depends on the,(A) amplitude of the sound waves produced by the sound source (B) distance the sound waves have traveled from the sound source (C) speed at which the sound waves traveled from the sound source (D) two of the above,D,"Loudness refers to how loud or soft a sound seems to a listener. The loudness of sound is determined, in turn, by the intensity of the sound waves. Intensity is a measure of the amount of energy in sound waves. The unit of intensity is the decibel (dB). "
"as distance from the sound source increases, the area covered by the sound waves decreases.",(A) true (B) false,B,"The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity results from two factors: the amplitude of the sound waves and how far they have traveled from the source of the sound. Amplitude is a measure of the size of sound waves. It depends on the amount of energy that started the waves. Greater amplitude waves have more energy and greater intensity, so they sound louder. As sound waves travel farther from their source, the more spread out their energy becomes. You can see how this works in the Figure 1.2. As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source. Q: Why can low-amplitude sounds like whispers be heard only over short distances? A: The sound waves already have so little energy that spreading them out over a wider area quickly reduces their intensity below the level of hearing. "
amplitude is a measure of the size of sound waves.,(A) true (B) false,A,"The intensity of sound waves determines the loudness of sounds, but what determines intensity? Intensity results from two factors: the amplitude of the sound waves and how far they have traveled from the source of the sound. Amplitude is a measure of the size of sound waves. It depends on the amount of energy that started the waves. Greater amplitude waves have more energy and greater intensity, so they sound louder. As sound waves travel farther from their source, the more spread out their energy becomes. You can see how this works in the Figure 1.2. As distance from the sound source increases, the area covered by the sound waves increases. The same amount of energy is spread over a greater area, so the intensity and loudness of the sound is less. This explains why even loud sounds fade away as you move farther from the source. Q: Why can low-amplitude sounds like whispers be heard only over short distances? A: The sound waves already have so little energy that spreading them out over a wider area quickly reduces their intensity below the level of hearing. "
which sound is considered to be extremely loud?,(A) dishwasher (B) lawn mower (C) vacuum cleaner (D) two of the above,B,"The Figure 1.1 shows decibel levels of several different sounds. As decibel levels get higher, sound waves have greater intensity and sounds are louder. For every 10-decibel increase in the intensity of sound, loudness is 10 times greater. Therefore, a 30-decibel quiet room is 10 times louder than a 20-decibel whisper, and a 40-decibel light rainfall is 100 times louder than the whisper. High-decibel sounds are dangerous. They can damage the ears and cause loss of hearing. Q: How much louder than a 20-decibel whisper is the 60-decibel sound of a vacuum cleaner? A: The vacuum cleaner is 10,000 times louder than the whisper! "
all combustion engines,(A) burn fuel to produce thermal energy (B) change thermal energy to kinetic energy (C) burn fuel inside the engine (D) two of the above,D,A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the energy to do work. Two basic types of combustion engines are external and internal combustion engines. 
"in an internal combustion engine, fuel is burned in the",(A) cylinders (B) valves (C) spark plugs (D) pistons,A,"An internal combustion engine burns fuel internally, or inside the engine. This type of engine is found not only in cars but in most other motor vehicles as well. The engine works in a series of steps, which keep repeating. You can follow the steps in the Figure 1.1. 1. A mixture of fuel and air is pulled-into a cylinder through a valve, which then closes. 2. A piston inside the cylinder moves upward, compressing the fuel-air mixture in the closed cylinder. The mixture is now under a lot of pressure and very warm. 3. A spark from a spark plug ignites the fuel-air mixture, causing it to burn explosively within the confined space of the closed cylinder. 4. The pressure of the hot gases from combustion pushes the piston downward. 5. The piston moves up again, pushing exhaust gases out of the cylinder through another valve. 6. The piston moves downward again, and the cycle repeats. Q: The internal combustion engine converts thermal energy to another form of energy. Which form of energy is it? A: The engine converts thermal energy to kinetic energy, or the energy of a moving objectin this case, the moving piston. "
a car engine provides the kinetic energy needed to,(A) turn the wheels (B) apply the brakes (C) power the lights (D) two of the above,A,"A combustion engine is a complex machine that burns fuel to produce thermal energy and then uses the energy to do work. In a car, the engine does the work of providing kinetic energy that turns the wheels. The combustion engine in a car is a type of engine called an internal combustion engine. (Another type of combustion engine is an external combustion engine.) "
all cars have at least eight cylinders.,(A) true (B) false,B,"Most cars have at least four cylinders connected to the crankshaft. Their pistons move up and down in sequence, one after the other. A powerful car may have eight pistons, and some race cars may have even more. The more cylinders a car engine has, the more powerful its engine can be. "
"the more pistons a car has, the greater the cars power is.",(A) true (B) false,A,"Most cars have at least four cylinders connected to the crankshaft. Their pistons move up and down in sequence, one after the other. A powerful car may have eight pistons, and some race cars may have even more. The more cylinders a car engine has, the more powerful its engine can be. "
what is the basic unit of mass in the international system of units?,(A) ounce (B) pound (C) gram (D) kilogram,C,"The example of the Mars Climate Orbiter shows the importance of using a standard system of measurement in science and technology. The measurement system used by most scientists and engineers is the International System of Units, or SI. There are a total of seven basic SI units, including units for length (meter) and mass (kilogram). SI units are easy to use because they are based on the number 10. Basic units are multiplied or divided by powers of ten to arrive at bigger or smaller units. Prefixes are added to the names of the units to indicate the powers of ten, as shown in the Table 1.1. Prefix kilo- (k) Multiply Basic Unit 1000 Basic Unit of Length = Meter (m) kilometer (km) = 1000 m Prefix deci- (d) centi- (c) milli- (m) micro- () nano- (n) Multiply Basic Unit 0.1 0.01 0.001 0.000001 0.000000001 Basic Unit of Length = Meter (m) decimeter (dm) = 0.1 m centimeter (cm) = 0.01 m millimeter (mm) = 0.001 m micrometer (m) = 0.000001 m nanometer (nm) = 0.000000001 m Q: What is the name of the unit that is one-hundredth (0.01) of a meter? A: The name of this unit is the centimeter. Q: What fraction of a meter is a decimeter? A: A decimeter is one-tenth (0.1) of a meter. "
the prefix that multiplies a basic si unit by 0.01 is,(A) kilo- (B) deci- (C) centi- (D) milli-,C,"The example of the Mars Climate Orbiter shows the importance of using a standard system of measurement in science and technology. The measurement system used by most scientists and engineers is the International System of Units, or SI. There are a total of seven basic SI units, including units for length (meter) and mass (kilogram). SI units are easy to use because they are based on the number 10. Basic units are multiplied or divided by powers of ten to arrive at bigger or smaller units. Prefixes are added to the names of the units to indicate the powers of ten, as shown in the Table 1.1. Prefix kilo- (k) Multiply Basic Unit 1000 Basic Unit of Length = Meter (m) kilometer (km) = 1000 m Prefix deci- (d) centi- (c) milli- (m) micro- () nano- (n) Multiply Basic Unit 0.1 0.01 0.001 0.000001 0.000000001 Basic Unit of Length = Meter (m) decimeter (dm) = 0.1 m centimeter (cm) = 0.01 m millimeter (mm) = 0.001 m micrometer (m) = 0.000001 m nanometer (nm) = 0.000000001 m Q: What is the name of the unit that is one-hundredth (0.01) of a meter? A: The name of this unit is the centimeter. Q: What fraction of a meter is a decimeter? A: A decimeter is one-tenth (0.1) of a meter. "
a kilogram equals one-thousandth of a gram.,(A) true (B) false,B,"Mass refers to the amount of matter. Mass is usually measured with a balance. A balance allows an object to be matched with other objects of known mass. The SI unit for mass is the kilogram. For smaller masses, grams are often used instead. You may have a balance in your classroom. The balance may be either a triple-beam balance or an electronic balance. The figure below of the old-fashioned balance may give you a better idea of what mass is. What does it mean when both sides of the balance are at the same level? Thats correct, it would mean the masses of each object are equal. In that case, the fruit would have a mass of 1 kg. It would have the same mass as the iron. As you can see, the fruit is at a higher level than the iron. This means the fruit has less mass than the 1 kg iron object. Q: What If the fruit were at a lower level than the iron object? A: The mass of the fruit would be greater than 1 kg. "
how do ionic bonds form?,(A) Atoms of metallic elements give up electrons to atoms of nonmetallic elements (B) Atoms of nonmetallic elements give up electrons to atoms of metallic elements (C) Atoms of metallic elements accept electrons from atoms of nonmetallic elements (D) two of the above,A,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
"in an ionic bond, the metallic ion is always a positive ion.",(A) true (B) false,A,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
positive ions are named by adding the suffix ide to the first part of the element name.,(A) true (B) false,B,"Like fluoride, other negative ions usually have names ending in -ide. Positive ions, on the other hand, are just given the element name followed by the word ion. For example, when a sodium atom loses an electron, it becomes a positive sodium ion. The charge of an ion is indicated by a plus (+) or minus sign (-), which is written to the right of and just above the ions chemical symbol. For example, the fluoride ion is represented by the symbol F , and the sodium ion is represented by the symbol Na+ . If the charge is greater than one, a number is used to indicate it. For example, iron (Fe) may lose two electrons to form an ion with a charge of plus two. This ion would be represented by the symbol Fe2+ . This and some other common ions are listed with their symbols in the Table 1.1. Cations Name of Ion Calcium ion Hydrogen ion Iron(II) ion Iron(III) ion Chemical Symbol Ca2+ H+ Fe2+ Fe3+ Anions Name of Ion Chloride Fluoride Bromide Oxide Chemical Symbol Cl F Br O2 Q: How does the iron(III) ion differ from the iron(II) ion? A: The iron(III) ion has a charge of +3, so it has one less electron than the iron(II) ion, which has a charge of +2. Q: What is the charge of an oxide ion? How does its number of electrons compare to its number of protons? A: An oxide ion has a charge of -2. It has two more electrons than protons. "
ionic bonds form only between metals and nonmetals.,(A) true (B) false,A,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
atoms of the element sodium want to give up an electron because sodium atoms,(A) already have seven valence electrons (B) do not need any electrons (C) have just one valence electron (D) form negative metal ions,C,"Ionic bonds form only between metals and nonmetals. Metals ""want"" to give up electrons, and nonmetals ""want"" to gain electrons. Find sodium (Na) in Figure 7.4. Sodium is an alkali metal in group 1. Like other group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level. Now find fluorine (F) in Figure 7.4. Fluorine is a halogen in group 17. It has seven valence electrons. If fluorine gains one electron, it will have a full outer energy level. After sodium gives up its valence electron to fluorine, both atoms have a more stable arrangement of electrons. "
metals in group 2 of the periodic table form ionic bonds with nonmetals in group,(A) 15 (B) 16 (C) 17 (D) 18,B,"Ionic bonds form only between metals and nonmetals. Thats because metals want to give up electrons, and nonmetals want to gain electrons. Find sodium (Na) in the Figure 1.2. Sodium is an alkali metal in group 1. Like all group 1 elements, it has just one valence electron. If sodium loses that one electron, it will have a full outer energy level, which is the most stable arrangement of electrons. Now find fluorine (F) in the periodic table Figure gains one electron, it will also have a full outer energy level and the most stable arrangement of electrons. Q: Predict what other elements might form ionic bonds. A: Metals on the left and in the center of the periodic table form ionic bonds with nonmetals on the right of the periodic table. For example, alkali metals in group 1 form ionic bonds with halogen nonmetals in group 17. "
ionic compounds form when ions of two different elements share electrons.,(A) true (B) false,B,"All compounds form when atoms of different elements share or transfer electrons. Compounds in which electrons are transferred from one atom to another are called ionic compounds. In this type of compound, electrons actually move between the atoms, rather than being shared between them. When atoms give up or accept electrons in this way, they become charged particles called ions. The ions are held together by ionic bonds, which form an ionic compound. Ionic compounds generally form between elements that are metals and elements that are nonmetals. For example, the metal calcium (Ca) and the nonmetal chlorine (Cl) form the ionic compound calcium chloride (CaCl2 ). In this compound, there are two negative chloride ions for each positive calcium ion. Because the positive and negative charges cancel out, an ionic compound is neutral in charge. Q: Now can you explain why calcium chloride prevents ice from forming on a snowy road? A: If calcium chloride dissolves in water, it breaks down into its ions (Ca2+ and Cl ). When water has ions dissolved in it, it has a lower freezing point. Pure water freezes at 0 C. With calcium and chloride ions dissolved in it, it wont freeze unless the temperature reaches -29 C or lower. "
an ionic compound is always neutral in charge.,(A) true (B) false,A,"Atoms are neutral in electric charge because they have the same number of electrons as protons. However, atoms may transfer electrons and become charged ions, as illustrated in Figure 23.5. Positively charged ions, or cations, form when atoms give up electrons. Negatively charged ions, or anions, form when atoms gain electrons. Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons either between two materials or within a material. Three ways this can occur are friction, conduction, and polarization. In all cases, the total charge remains the same. Electrons move, but they arent destroyed. This is the law of conservation of charge. "
how are ionic compounds named?,(A) The positive ion comes first in the compound name (B) The negative ion comes first in the compound name (C) The ion in the higher-numbered period comes first in the compound name (D) two of the above,A,"Ionic compounds are named for their positive and negative ions. The name of the positive ion always comes first, followed by the name of the negative ion. For example, positive sodium ions and negative chloride ions form the compound named sodium chloride. Similarly, positive calcium ions and negative chloride ions form the compound named calcium chloride. Q: What is the name of the ionic compound that is composed of positive barium ions and negative iodide ions? A: The compound is named barium iodide. "
properties of ionic compounds include,(A) high melting point (B) ability to conduct electricity (C) brittleness (D) two of the above,D,"The crystal structure of ionic compounds is strong and rigid. It takes a lot of energy to break all those strong ionic bonds. As a result, ionic compounds are solids with high melting and boiling points (see Table 7.2). The rigid crystals are brittle and more likely to break than bend when struck. As a result, ionic crystals tend to shatter. You can learn more about the properties of ionic compounds by watching the video at this URL:  MEDIA Click image to the left or use the URL below. URL:  Compare the melting and boiling points of these ionic compounds with those of water (0C and 100C), which is not an ionic compound. Ionic Compound Sodium chloride (NaCl) Calcium chloride (CaCl2 ) Barium oxide (BaO) Iron bromide (FeBr3 ) Melting Point (C) 801 772 1923 684 Boiling Point (C) 1413 1935 2000 934 Solid ionic compounds are poor conductors of electricity. The strong bonds between ions lock them into place in the crystal. However, in the liquid state, ionic compounds are good conductors of electricity. Most ionic compounds dissolve easily in water. When they dissolve, they separate into individual ions. The ions can move freely, so they are good conductors of electricity. Dissolved ionic compounds are called electrolytes. "
uses of ionic compounds include,(A) making fireworks (B) detecting moisture (C) melting ice (D) all of the above,D,Ionic compounds have many uses. Some are shown in the Figure 1.2. Many ionic compounds are used in industry. The human body needs several ions for good health. Having low levels of the ions can endanger important functions such as heartbeat. Solutions of ionic compounds can be used to restore the ions. 
an iodine atom has 53 protons. how many electrons does an iodine anion have?,(A) at least 54 (B) 53 or more (C) 53 or less (D) none of the above,A,"Atoms cannot only gain extra electrons. They can also lose electrons. In either case, they become ions. Ions are atoms that have a positive or negative charge because they have unequal numbers of protons and electrons. If atoms lose electrons, they become positive ions, or cations. If atoms gain electrons, they become negative ions, or anions. Consider the example of fluorine (see Figure 1.1). A fluorine atom has nine protons and nine electrons, so it is electrically neutral. If a fluorine atom gains an electron, it becomes a fluoride ion with an electric charge of -1. "
what is the name of the ion represented by the following symbol? o2-,(A) oxygen ion (B) dioxide (C) oxide (D) none of the above,C,"Like fluoride, other negative ions usually have names ending in -ide. Positive ions, on the other hand, are just given the element name followed by the word ion. For example, when a sodium atom loses an electron, it becomes a positive sodium ion. The charge of an ion is indicated by a plus (+) or minus sign (-), which is written to the right of and just above the ions chemical symbol. For example, the fluoride ion is represented by the symbol F , and the sodium ion is represented by the symbol Na+ . If the charge is greater than one, a number is used to indicate it. For example, iron (Fe) may lose two electrons to form an ion with a charge of plus two. This ion would be represented by the symbol Fe2+ . This and some other common ions are listed with their symbols in the Table 1.1. Cations Name of Ion Calcium ion Hydrogen ion Iron(II) ion Iron(III) ion Chemical Symbol Ca2+ H+ Fe2+ Fe3+ Anions Name of Ion Chloride Fluoride Bromide Oxide Chemical Symbol Cl F Br O2 Q: How does the iron(III) ion differ from the iron(II) ion? A: The iron(III) ion has a charge of +3, so it has one less electron than the iron(II) ion, which has a charge of +2. Q: What is the charge of an oxide ion? How does its number of electrons compare to its number of protons? A: An oxide ion has a charge of -2. It has two more electrons than protons. "
the process in which ions form is called ionization.,(A) true (B) false,A,"The process in which an atom becomes an ion is called ionization. It may occur when atoms are exposed to high levels of radiation. The radiation may give their outer electrons enough energy to escape from the attraction of the positive nucleus. However, most ions form when atoms transfer electrons to or from other atoms or molecules. For example, sodium atoms may transfer electrons to chlorine atoms. This forms positive sodium ions (Na+ ) and negative chloride ions (Cl ). Click image to the left or use the URL below. URL: "
ways in which ions may form include,(A) exposure to radiation (B) transfer of electrons between atoms (C) sharing of electrons between atoms (D) two of the above,D,"The process in which an atom becomes an ion is called ionization. It may occur when atoms are exposed to high levels of radiation. The radiation may give their outer electrons enough energy to escape from the attraction of the positive nucleus. However, most ions form when atoms transfer electrons to or from other atoms or molecules. For example, sodium atoms may transfer electrons to chlorine atoms. This forms positive sodium ions (Na+ ) and negative chloride ions (Cl ). Click image to the left or use the URL below. URL: "
ions are very unreactive.,(A) true (B) false,B,"Ions are highly reactive, especially as gases. They usually react with ions of opposite charge to form neutral compounds. For example, positive sodium ions and negative chloride ions react to form the neutral compound sodium chloride, commonly known as table salt. This occurs because oppositely charged ions attract each other. Ions with the same charge, on the other hand, repel each other. Ions are also deflected by a magnetic field, as you saw in the opening image of the northern lights. "
ions are deflected by a magnetic field.,(A) true (B) false,A,"Like the electric field that surrounds a charged particle, a magnetic field surrounds a magnet. This is the area around the magnet where it exerts magnetic force. Figure 24.3 shows the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. To see an animated magnetic field of a bar magnet, go to this URL: http://elgg.norfolk.e2bn.org/jsmith112/files/68/149/ When two magnets are brought close together, their magnetic fields interact. You can see how in Figure 24.4. The drawings show how lines of force of north and south poles attract each other whereas those of two north poles repel each other. The animations at the URL below show how magnetic field lines change as two or more magnets move in relation to each other. You can take an animated quiz to check your understanding of magnetic field interactions at this URL: http://elgg. "
only unsaturated hydrocarbons have isomers.,(A) true (B) false,B,"Unsaturated hydrocarbons contain at least one double or triple bond between carbon atoms. As a result, the carbon atoms are unable to bond with as many hydrogen atoms as they would if they were joined only by single bonds. This makes them unsaturated with hydrogen. Unsaturated hydrocarbons are classified on the basis of their bonds as alkenes, alkynes, or aromatic hydrocarbons. "
which statement about the isomers of a given hydrocarbon is true?,(A) They have the same chemical formula (B) They have the same structural formula (C) They have the same number of carbon atoms (D) two of the above,D,"Butane has only two isomers and pentane has just three, but some hydrocarbons have many more isomers than these. As you increase the number of carbon atoms in a hydrocarbon, the number of isomers quickly increases. For example, heptane, with seven carbon atoms, has nine isomers; and dodecane, with twelve carbon atoms, has 355 isomers. Some hydrocarbons with many more carbon atoms have billions of isomers! Q: Why does the number of carbon atoms in a hydrocarbon determine how many isomers it has? A: The more carbon atoms there are, the greater the number of possible arrangements of carbon atoms. "
how many isomers does pentane have?,(A) 1 (B) 2 (C) 3 (D) 4,C,"Butane has only two isomers and pentane has just three, but some hydrocarbons have many more isomers than these. As you increase the number of carbon atoms in a hydrocarbon, the number of isomers quickly increases. For example, heptane, with seven carbon atoms, has nine isomers; and dodecane, with twelve carbon atoms, has 355 isomers. Some hydrocarbons with many more carbon atoms have billions of isomers! Q: Why does the number of carbon atoms in a hydrocarbon determine how many isomers it has? A: The more carbon atoms there are, the greater the number of possible arrangements of carbon atoms. "
some hydrocarbons have billions of isomers.,(A) true (B) false,A,"Butane has only two isomers and pentane has just three, but some hydrocarbons have many more isomers than these. As you increase the number of carbon atoms in a hydrocarbon, the number of isomers quickly increases. For example, heptane, with seven carbon atoms, has nine isomers; and dodecane, with twelve carbon atoms, has 355 isomers. Some hydrocarbons with many more carbon atoms have billions of isomers! Q: Why does the number of carbon atoms in a hydrocarbon determine how many isomers it has? A: The more carbon atoms there are, the greater the number of possible arrangements of carbon atoms. "
"the more branching an isomer has, the lower its melting point is.",(A) true (B) false,A,"Because isomers are different compounds, they have different properties. Generally, branched-chain isomers have lower boiling and melting points than straight-chain isomers. For example, the boiling and melting points of iso- butane are -12  C and -160  C, respectively, compared with 0  C and -138  C for n-butane. The more branching there is, the lower the boiling and melting points are. Q: The boiling point of n-pentane is 36  C. Predict the boiling points of iso-pentane and neo-pentane. A: The boiling point of iso-pentane is 28  C, and the boiling point of neo-pentane is 10  C. "
all isotopes form naturally.,(A) true (B) false,B,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
all isotopes are radioactive.,(A) true (B) false,B,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
deuterium is an isotope of,(A) oxygen (B) helium (C) carbon (D) hydrogen,D,"Hydrogen is an example of an element that has isotopes. Three isotopes of hydrogen are modeled in the Figure hydrogen. Some hydrogen atoms have one neutron as well. These atoms are the isotope named deuterium. Other hydrogen atoms have two neutrons. These atoms are the isotope named tritium. Q: The mass number of an atom is the sum of its protons and neutrons. What is the mass number of each isotope of hydrogen shown above? A: The mass numbers are: hydrogen = 1, deuterium = 2, and tritium = 3. "
how many neutrons does the isotope in question 6 have?,(A) one (B) two (C) three (D) four,A,"For most other elements, isotopes are named for their mass number. For example, carbon atoms with the usual 6 neutrons have a mass number of 12 (6 protons + 6 neutrons = 12), so they are called carbon-12. Carbon atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms are the isotope called carbon-13. Some carbon atoms have 8 neutrons. What is the name of this isotope of carbon? You can learn more about this isotope at the URL below. It is used by scientists to estimate the ages of rocks and fossils. "
things with kinetic energy can do work.,(A) true (B) false,A,"Kinetic energy is the energy of moving matter. Anything that is moving has kinetic energyfrom atoms in matter to stars in outer space. Things with kinetic energy can do work. For example, the spinning saw blade in the photo above is doing the work of cutting through a piece of metal. "
an objects mass has a greater influence on its kinetic energy than does its velocity.,(A) true (B) false,B,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
how much kinetic energy does a 50-kg object have if it is moving at a velocity of 2 m/s?,(A) 200 J (B) 100 J (C) 50 J (D) none of the above,B,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
"if the object in question 6 slows down to a velocity of 1 m/s, how much kinetic energy does it have?",(A) 100 J (B) 50 J (C) 25 J (D) none of the above,C,"The amount of kinetic energy in a moving object depends directly on its mass and velocity. An object with greater mass or greater velocity has more kinetic energy. You can calculate the kinetic energy of a moving object with this equation: Kinetic Energy (KE) = 12 mass  velocity2 This equation shows that an increase in velocity increases kinetic energy more than an increase in mass. If mass doubles, kinetic energy doubles as well, but if velocity doubles, kinetic energy increases by a factor of four. Thats because velocity is squared in the equation. Lets consider an example. The Figure 1.1 shows Juan running on the beach with his dad. Juan has a mass of 40 kg and is running at a velocity of 1 m/s. How much kinetic energy does he have? Substitute these values for mass and velocity into the equation for kinetic energy: m2 2 KE = 12  40 kg  (1 m s ) = 20 kg  s2 = 20 N  m, or 20 J Notice that the answer is given in joules (J), or N  m, which is the SI unit for energy. One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. What about Juans dad? His mass is 80 kg, and hes running at the same velocity as Juan (1 m/s). Because his mass is twice as great as Juans, his kinetic energy is twice as great: m2 2 KE = 12  80 kg  (1 m s ) = 40 kg  s2 = 40 N  m, or 40 J Q: What is Juans kinetic energy if he speeds up to 2 m/s from 1 m/s? A: By doubling his velocity, Juan increases his kinetic energy by a factor of four: m2 2 KE = 12  40 kg  (2 m s ) = 80 kg  s2 = 80 N  m, or 80 J "
energy can be measured in the si unit n  m.,(A) true (B) false,A,"Because energy is the ability to do work, it is expressed in the same unit that is used for work. The SI unit for both work and energy is the joule (J), or Newton  meter (N  m). One joule is the amount of energy needed to apply a force of 1 Newton over a distance of 1 meter. For example, suppose the boy in the Figure 1.1 applies 20 Newtons of force to his tennis racket over a distance of 1 meter. The energy needed to do this work is 20 N m, or 20 J. "
"if particles of matter do not have enough kinetic energy to slide past one another, then the matter exists as a",(A) gas (B) solid (C) liquid (D) plasma,B,"Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the ""war"" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do is vibrate. This explains why solids have a fixed volume and shape. In liquids, particles have enough kinetic energy to partly overcome the force of attraction between them. They can slide past one another but not pull completely apart. This explains why liquids can change shape but have a fixed volume. In gases, particles have a lot of kinetic energy. They can completely overcome the force of attraction between them and move apart. This explains why gases have neither a fixed volume nor a fixed shape. "
the particles of solids do not have enough energy to move.,(A) true (B) false,B,"Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the ""war"" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do is vibrate. This explains why solids have a fixed volume and shape. In liquids, particles have enough kinetic energy to partly overcome the force of attraction between them. They can slide past one another but not pull completely apart. This explains why liquids can change shape but have a fixed volume. In gases, particles have a lot of kinetic energy. They can completely overcome the force of attraction between them and move apart. This explains why gases have neither a fixed volume nor a fixed shape. "
"as the kinetic energy of particles of matter increases, the distance between the particles",(A) vibrates (B) increases (C) decreases (D) remains constant,B,"Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the ""war"" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do is vibrate. This explains why solids have a fixed volume and shape. In liquids, particles have enough kinetic energy to partly overcome the force of attraction between them. They can slide past one another but not pull completely apart. This explains why liquids can change shape but have a fixed volume. In gases, particles have a lot of kinetic energy. They can completely overcome the force of attraction between them and move apart. This explains why gases have neither a fixed volume nor a fixed shape. "
scientists think that the particles of all matter are in constant motion.,(A) true (B) false,A,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
particles of liquids have enough energy to separate from other liquid particles.,(A) true (B) false,B,"Particles of matter of the same substance, such as the same element, are attracted to one another. The force of attraction tends to pull the particles closer together. The particles need a lot of kinetic energy to overcome the force of attraction and move apart. Its like a tug of war between opposing forces. The kinetic energy of individual particles is on one side, and the force of attraction between different particles is on the other side. The outcome of the ""war"" depends on the state of matter. This is illustrated in Figure 4.8 and in the animation at this URL: http://w In solids, particles dont have enough kinetic energy to overcome the force of attraction between them. The particles are packed closely together and cannot move around. All they can do is vibrate. This explains why solids have a fixed volume and shape. In liquids, particles have enough kinetic energy to partly overcome the force of attraction between them. They can slide past one another but not pull completely apart. This explains why liquids can change shape but have a fixed volume. In gases, particles have a lot of kinetic energy. They can completely overcome the force of attraction between them and move apart. This explains why gases have neither a fixed volume nor a fixed shape. "
"whenever an action and reaction occur, momentum is",(A) created (B) destroyed (C) transferred (D) none of the above,C,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
"when momentum is transferred from one object to another, their combined momentum remains the same.",(A) true (B) false,A,"When an action and reaction occur, momentum is transferred from one object to the other. However, the com- bined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Consider the example of a truck colliding with a car, which is illustrated in Figure 14.11. Both vehicles are moving in the same direction before and after the collision, but the truck is moving faster than the car before the collision occurs. During the collision, the truck transfers some of its momentum to the car. After the collision, the truck is moving slower and the car is moving faster than before the collision occurred. Nonetheless, their combined momentum is the same both before and after the collision. You can see an animation showing how momentum is conserved in a head-on collision at this URL:  . "
"when light reflects off a smooth surface, it forms a clear image.",(A) true (B) false,A,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
the type of reflection described in question 3 is called,(A) normal reflection (B) diffuse reflection (C) regular reflection (D) none of the above,C,"If a surface is extremely smooth, as it is in a mirror, then the image formed by reflection is sharp and clear. This is called regular reflection (also called specular reflection). However, if the surface is even slightly rough or bumpy, an image may not form, or if there is an image, it is blurry or fuzzy. This is called diffuse reflection. Q: Look at the boats and their images in the Figure 1.1. Which one represents regular reflection, and which one represents diffuse reflection? A: Reflection of the boat on the left is regular reflection. The water is smooth and the image is sharp and clear. Reflection of the boat on the right is diffuse reflection. The water has ripples and the image is blurry and wavy. In the Figure 1.2, you can see how both types of reflection occur. Waves of light are represented by arrows called rays. Rays that strike the surface are referred to as incident rays, and rays that reflect off the surface are known as reflected rays. In regular reflection, all the rays are reflected in the same direction. This explains why regular reflection forms a clear image. In diffuse reflection, the rays are reflected in many different directions. This is why diffuse reflection forms, at best, a blurry image. "
rays of light are reflected in many different directions in,(A) specular reflection (B) regular reflection (C) diffuse reflection (D) all of the above,C,Almost all surfaces reflect some of the light that strikes them. The still water of the lake in Figure 22.9 reflects almost all of the light that strikes it. The reflected light forms an image of nearby objects. An image is a copy of an object that is formed by reflected or refracted light. 
the image formed when light rays are reflected as described in question 5 is blurry or fuzzy.,(A) true (B) false,A,"If a surface is extremely smooth, as it is in a mirror, then the image formed by reflection is sharp and clear. This is called regular reflection (also called specular reflection). However, if the surface is even slightly rough or bumpy, an image may not form, or if there is an image, it is blurry or fuzzy. This is called diffuse reflection. Q: Look at the boats and their images in the Figure 1.1. Which one represents regular reflection, and which one represents diffuse reflection? A: Reflection of the boat on the left is regular reflection. The water is smooth and the image is sharp and clear. Reflection of the boat on the right is diffuse reflection. The water has ripples and the image is blurry and wavy. In the Figure 1.2, you can see how both types of reflection occur. Waves of light are represented by arrows called rays. Rays that strike the surface are referred to as incident rays, and rays that reflect off the surface are known as reflected rays. In regular reflection, all the rays are reflected in the same direction. This explains why regular reflection forms a clear image. In diffuse reflection, the rays are reflected in many different directions. This is why diffuse reflection forms, at best, a blurry image. "
the angles of reflection and incidence are measured relative to a line that is parallel to the reflective surface.,(A) true (B) false,B,One thing is true of both regular and diffuse reflection. The angle at which the reflected rays leave the surface is equal to the angle at which the incident rays strike the surface. This is known as the law of reflection. The law is illustrated in the Figure 1.3. 
a lens reflects light and forms an image.,(A) true (B) false,B,"A lens is a transparent object with one or two curved surfaces. It is typically made of glass (or clear plastic in the case of a contact lens). A lens refracts, or bends, light and forms an image. An image is a copy of an objected formed by the refraction (or reflection) of visible light. The more curved the surface of a lens is, the more it refracts the light that passes through it. There are two basic types of lenses: concave and convex. The two types of lenses have different shapes, so they bend light and form images in different ways. "
"the less curved the surface of a lens is, the more the lens refracts light.",(A) true (B) false,B,"Lenses make use of the refraction of light to create images. A lens is a transparent object, typically made of glass, with one or two curved surfaces. The more curved the surface of a lens is, the more it refracts light. Like mirrors, lenses may be concave or convex. "
the image of an object formed by a concave lens is always,(A) on the same side of the lens as the object (B) smaller than the object (C) right-side up (D) all of the above,D,"Concave lenses are thicker at the edges than in the middle. They cause rays of light to diverge, or spread apart. Figure 22.16 shows how a concave lens forms an image. The image is always virtual and on the same side of the lens as the object. The image is also right-side up and smaller than the object. Concave lenses are used in cameras. They focus reduced images inside the camera, where they are captured and stored. You can explore the formation of images by a concave lens with the interactive animation at this URL: http://phet.colorado.edu/sims/geometric-opti "
a concave lens forms only real images.,(A) true (B) false,B,"Concave lenses are thicker at the edges than in the middle. They cause rays of light to diverge, or spread apart. Figure 22.16 shows how a concave lens forms an image. The image is always virtual and on the same side of the lens as the object. The image is also right-side up and smaller than the object. Concave lenses are used in cameras. They focus reduced images inside the camera, where they are captured and stored. You can explore the formation of images by a concave lens with the interactive animation at this URL: http://phet.colorado.edu/sims/geometric-opti "
a convex lens forms a virtual image when the object is,(A) closer to the lens than the focus is (B) farther from the lens than the focus is (C) the same distance from the lens as the focus is (D) on the opposite side of the lens from the focus,A,"A concave lens is thicker at the edges than it is in the middle. You can see the shape of a concave lens in the Figure Note that the image formed by a concave lens is on the same side of the lens as the object. It is also smaller than the object and right-side up. However, it isnt a real image. It is a virtual image. Your brain tricks you into seeing an image there. The light rays actually pass through the glass to the other side and spread out in all directions. "
levers that change the direction of the force are,(A) first class levers (B) second class levers (C) third class levers (D) all of the above,A,"Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which it is applied. Two examples of machines that work in this way are claw hammers and the rope systems (pulleys) that raise or lower flags on flagpoles. Figure 16.10 explains how these machines work. In each case, the direction of the force applied by the user is reversed by the machine. How does this make it easier to do the job? "
examples of first-class levers include,(A) see saws (B) wheelbarrows (C) rakes (D) two of the above,A,"Did you ever use a hammer to pull a nail out of a board? If not, you can see how its done in Figure 16.18. When you pull down on the handle of the hammer, the claw end pulls up on the nail. A hammer is an example of a lever. A lever is a simple machine consisting of a bar that rotates around a fixed point called the fulcrum. For a video introduction to levers using skateboards as examples, go to this link:  MEDIA Click image to the left or use the URL below. URL:  A lever may or may not increase the force applied, and it may or may not change the direction of the force. It all depends on the location of the input and output forces relative to the fulcrum. In this regard, there are three basic types of levers, called first-class, second-class, and third-class levers. Figure 16.19 describes the three classes. "
all of the following are third-class levers except,(A) brooms (B) hockey sticks (C) rakes (D) wheelbarrows,D,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
a second class lever always has an ideal mechanical advantage less than 1.,(A) true (B) false,B,"All three classes of levers make work easier, but they do so in different ways. When the input and output forces are on opposite sides of the fulcrum, the lever changes the direction of the applied force. This occurs only with a first-class lever. When both the input and output forces are on the same side of the fulcrum, the direction of the applied force does not change. This occurs with both second- and third-class levers. When the input force is applied farther from the fulcrum, the input distance is greater than the output distance, so the ideal mechanical advantage is greater than 1. This always occurs with second-class levers and may occur with first-class levers. When the input force is applied closer to the fulcrum, the input distance is less than the output distance, so the ideal mechanical advantage is less than 1. This always occurs with third-class levers and may occur with first-class levers. When both forces are the same distance from the fulcrum, the input distance equals the output distance, so the ideal mechanical advantage equals 1. This occurs only with first class-levers. "
a third class lever always applies the output force over a greater distance than the input force.,(A) true (B) false,A,"You may be wondering why you would use a third-class lever when it doesnt change the direction or strength of the applied force. The advantage of a third-class lever is that the output force is applied over a greater distance than the input force. This means that the output end of the lever must move faster than the input end. Why would this be useful when you are moving a hockey stick or baseball bat, both of which are third-class levers? "
sunlight carries the complete range of wavelengths of electromagnetic waves.,(A) true (B) false,A,"Electromagnetic waves are waves that carry energy through matter or space as vibrating electric and magnetic fields. Electromagnetic waves have a wide range of wavelengths and frequencies. Sunlight contains the complete range of wavelengths of electromagnetic waves, which is called the electromagnetic spectrum. The Figure 1.1 shows all the waves in the spectrum. "
light includes,(A) visible light (B) ultraviolet light (C) infrared light (D) all of the above,D,"The Suns surface features are quite visible, but only with special equipment. For example, sunspots are only visible with special light-filtering lenses. "
sources of infrared light include,(A) the sun (B) flames (C) living things (D) all of the above,D,"Light with the longest wavelengths is called infrared light. The term infrared means ""below red."" Infrared light is the range of light waves that have longer wavelengths than red light in the visible spectrum. You cant see infrared light waves, but you can feel them as heat on your skin. The sun gives off infrared light as do fires and living things. The picture of a cat that opened this chapter was made with a camera that detects infrared light waves and changes their energy to colored light in the visible range. Night vision goggles, which are used by law enforcement and the military, also detect infrared light waves. The goggles convert the invisible waves to visible images. For a deeper understanding of infrared light, watch the video at this URL:  MEDIA Click image to the left or use the URL below. URL: "
visible light with the highest frequencies appears to our eyes as the color,(A) red (B) yellow (C) green (D) violet,D,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
ultraviolet light can be used to kill bacteria in food.,(A) true (B) false,A,"Bacteria in food or water usually can be killed by heating it to a high temperature. Generally, this temperature is at least 71 C (160 F). Bacteria on surfaces such as countertops and floors can be killed with disinfectants, such as chlorine bleach. Bacterial infections in people can be treated with antibiotic drugs. These drugs kill bacteria and may quickly cure the disease. If youve ever had strep throat, you were probably prescribed an antibiotic to treat it. Some bacteria have developed antibiotic resistance. They have evolved traits that make them resistant to one or more antibiotic drugs. You can see how this happens in Figure 8.14. Its an example of natural selection. Some bacteria are now resistant to most common antibiotic drugs. These infections are very hard to treat. "
lipids are biochemical compounds that include fats and oils.,(A) true (B) false,A,"Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. "
all lipids contain,(A) oxygen (B) nitrogen (C) phosphorus (D) two of the above,A,"Lipids are biochemical compounds such as fats and oils. Organisms use lipids to store energy. In addition to carbon and hydrogen, lipids contain oxygen. "
lipids known as fats consist of saturated fatty acids.,(A) true (B) false,A,"Lipids are made up of long carbon chains called fatty acids. Like hydrocarbons, fatty acids may be saturated or unsaturated. Figure 9.21 shows structural formulas for two small fatty acids. One is saturated and one is unsaturated. In saturated fatty acids, there are only single bonds between carbon atoms. As a result, the carbons are saturated with hydrogen atoms. Saturated fatty acids are found in fats. Fats are solid lipids that animals use to store energy. In unsaturated fatty acids, there is at least one double bond between carbon atoms. As a result, some carbons are not bonded to as many hydrogen atoms as possible. Unsaturated fatty acids are found in oils. Oils are liquid lipids that plants use to store energy. "
unsaturated fatty acids contain only single bonds between carbon atoms.,(A) true (B) false,B,"Lipids consist only or mainly of carbon, hydrogen, and oxygen. Both fats and oils are made up of long chains of carbon atoms that are bonded together. These chains are called fatty acids. Fatty acids may be saturated or (A) The white bands on these lamb chops are fat. (B) The yellow liquid in this bottle is olive oil. unsaturated. In the Figure 1.2 you can see structural formulas for two small fatty acids, one saturated and one unsaturated. Saturated fatty acids have only single bonds between carbon atoms. As a result, the carbon atoms are bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogens. Saturated fatty acids are found in fats. Unsaturated fatty acids have at least one double bond between carbon atoms. As a result, some carbon atoms are not bonded to as many hydrogen atoms as possible. They are unsaturated with hydrogens. Unsaturated fatty acids are found in oils. Q: Both of these fatty acid molecules have six carbon atoms and two oxygen atoms. How many hydrogen atoms does each fatty acid molecule contain? What else is different about the two molecules? A: The saturated fatty acid molecule has 12 hydrogen atoms. This is as many hydrogen atoms as can possibly be bonded to carbon atoms in this molecule. The unsaturated fatty acid molecule has 10 hydrogen atoms, or two less than the maximum possible number. The saturated fatty acid has only single bonds between its carbon atoms. The unsaturated fatty acid has a double bond between two of its carbon atoms. "
a longitudinal wave is a type of mechanical wave.,(A) true (B) false,A,"A longitudinal wave is a type of mechanical wave. A mechanical wave is a wave that travels through matter, called the medium. In a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. You can see this in the Figure 1.1. The persons hand pushes and pulls on one end of the spring. The energy of this disturbance passes through the coils of the spring to the other end. Click image to the left or use the URL below. URL: "
"in a longitudinal wave, particles of the medium vibrate in a direction that is perpendicular to the direction the wave travels.",(A) true (B) false,B,"A longitudinal wave is a type of mechanical wave. A mechanical wave is a wave that travels through matter, called the medium. In a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. You can see this in the Figure 1.1. The persons hand pushes and pulls on one end of the spring. The energy of this disturbance passes through the coils of the spring to the other end. Click image to the left or use the URL below. URL: "
earthquakes cause longitudinal waves called p waves.,(A) true (B) false,A,"Earthquakes cause longitudinal waves as well as transverse waves. The disturbance that causes an earthquake sends longitudinal waves through underground rocks in all directions from the disturbance. Earthquake waves that travel this way are called primary, or P, waves. They are illustrated in Figure 19.7. "
a longitudinal wave that carries more energy has particles that are,(A) closer together in rarefactions (B) father apart in compressions (C) the same distance apart everywhere (D) none of the above,D,"A longitudinal wave is a type of mechanical wave. A mechanical wave is a wave that travels through matter, called the medium. In a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. You can see this in the Figure 1.1. The persons hand pushes and pulls on one end of the spring. The energy of this disturbance passes through the coils of the spring to the other end. Click image to the left or use the URL below. URL: "
earths magnetic poles have switched places repeatedly in the past.,(A) true (B) false,A,"Earths magnetic poles have switched places repeatedly in the past. As you can see in the Figure 1.1, each time the switch occurred, Earths magnetic field was reversed. The magnetic field is the region around a magnet over which it exerts magnetic force. We think of todays magnetic field direction as normal, but thats only because its what were used to. "
scientists know for certain why magnetic field reversals occur.,(A) true (B) false,B,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
evidence for magnetic field reversals,(A) covers 100s of millions of years (B) was discovered on the ocean floor (C) comes from the magnetic domains of rocks (D) all of the above,D,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
when did the last magnetic reversal occur?,(A) more than 330 million years ago (B) about 300 million years ago (C) about 100 million years ago (D) less than 1 million years ago,D,"Do you like to read science fiction? Science fiction writers are really creative. For example, an author might write about a time in the distant past when compasses pointed south instead of north. Actually, this idea isnt fictionits a fact! Earths magnetic poles have switched places repeatedly over the past hundreds of millions of years, each time reversing Earths magnetic field. This is illustrated in Figure 24.13. Scientists dont know for certain why magnetic reversals occur, but there is hard evidence showing that they have occurred. The evidence comes from rocks on the ocean floor. Look at Figure 24.14, which shows a ridge on the ocean floor. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. The newly hardened rock is then gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. Rock samples from many places on the ocean floor reveal that magnetic domains of rocks from different time periods are aligned in opposite directions. The evidence shows that Earths magnetic field reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. What might happen if a magnetic reversal occurred in your lifetime? How might it affect you? You can learn more about Earths magnetic reversals at this URL:  . "
rocks on the ocean floor far from a ridge,(A) are older than rocks close to the ridge (B) always have reversed polarity (C) keep reversing the polarity of their magnetic domains (D) two of the above,A,"The scientists used geologic dating techniques on seafloor rocks. They found that the youngest rocks on the seafloor were at the mid-ocean ridges. The rocks get older with distance from the ridge crest. The scientists were surprised to find that the oldest seafloor is less than 180 million years old. This may seem old, but the oldest continental crust is around 4 billion years old. Scientists also discovered that the mid-ocean ridge crest is nearly sediment free. The crust is also very thin there. With distance from the ridge crest, the sediments and crust get thicker. This also supports the idea that the youngest rocks are on the ridge axis and that the rocks get older with distance away from the ridge (Figure 6.12). Something causes the seafloor to be created at the ridge crest. The seafloor is also destroyed in a relatively short time. "
"after magma hardens, the alignment of magnetic domains reverses with each magnetic field reversal.",(A) true (B) false,B,"Scientists dont know for certain why magnetic reversals occur, but there is hard evidence that they have for hundreds of millions of years. The evidence comes from rocks on the ocean floor. Look at Figure 1.2. They show the same ridge on the ocean floor during different periods of time. A. At the center of the ridge, hot magma pushes up through the crust and hardens into rock. Once the magma hardens, the alignment of magnetic domains in the rock is frozen in place forever. Magnetic domains are regions in the rocks where all the atoms are lined up and pointing toward Earths north magnetic pole. B. The newly hardened rock is gradually pushed away from the ridge in both directions as more magma erupts and newer rock forms. The alignment of magnetic domains in this new rock is in the opposite direction, showing that a magnetic reversal has occurred. C. A magnetic reversal occurs again. It is frozen in rock to document the change. Rock samples from many places on the ocean floor show that the north and south magnetic poles reversed hundreds of times over the last 330 million years. The last reversal was less than a million years ago. "
only bar magnets have north and south magnetic poles.,(A) true (B) false,B,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
"if you cut a bar magnet in half, one half will have just a north pole and the other half will have just a south pole.",(A) true (B) false,B,"All magnets have two magnetic poles. The poles are regions where the magnet is strongest. The poles are called north and south because they always line up with Earths north-south axis if the magnet is allowed to move freely. (Earths axis is the imaginary line around which the planet rotates.) What do you suppose would happen if you cut the bar magnet in Figure 24.2 in half along the line between the north and south poles? Both halves would also have north and south poles. If you cut each of the halves in half, all those pieces would have north and south poles as well. Pieces of a magnet always have both north and south poles no matter how many times you cut the magnet. "
a magnets force is,(A) a force of repulsion only (B) a force of attraction only (C) exerted over a distance (D) two of the above,C,"The force that a magnet exerts on certain materials is called magnetic force. Like electric force, magnetic force is exerted over a distance and includes forces of attraction and repulsion. North and south poles of two magnets attract each other, while two north poles or two south poles repel each other. "
"when two magnets are brought close together, their magnetic fields interact.",(A) true (B) false,A,"Like the electric field that surrounds a charged particle, a magnetic field surrounds a magnet. This is the area around the magnet where it exerts magnetic force. Figure 24.3 shows the magnetic field surrounding a bar magnet. Tiny bits of iron, called iron filings, were placed under a sheet of glass. When the magnet was placed on the glass, it attracted the iron filings. The pattern of the iron filings shows the lines of force that make up the magnetic field of the magnet. The concentration of iron filings near the poles indicates that these areas exert the strongest force. To see an animated magnetic field of a bar magnet, go to this URL: http://elgg.norfolk.e2bn.org/jsmith112/files/68/149/ When two magnets are brought close together, their magnetic fields interact. You can see how in Figure 24.4. The drawings show how lines of force of north and south poles attract each other whereas those of two north poles repel each other. The animations at the URL below show how magnetic field lines change as two or more magnets move in relation to each other. You can take an animated quiz to check your understanding of magnetic field interactions at this URL: http://elgg. "
lines of force around two magnetic poles push apart when,(A) both poles are north poles (B) both poles are south poles (C) one pole is a north pole and one pole is a south pole (D) two of the above,D,"When charged particles are close enough to exert force on each other, their electric fields interact. This is illustrated in the Figure 1.2. The lines of force bend together when particles with different charges attract each other. The lines bend apart when particles with like charges repel each other. Q: What would the lines of force look like around two negative particles? A: They would look like the lines around two positive particles, except the arrows would point toward, rather than away from, the negative particles. "
ways that machines may make work easier include changing the,(A) amount of force applied (B) distance over which force is applied (C) direction in which force is applied (D) any of the above,D,"Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Q: If a machine increases the force applied, what does this tell you about the distance over which the force is applied by the machine: A: The machine must apply the force over a shorter distance. Thats because a machine doesnt change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease. For the same reason, if a machine increases the distance over which the force is applied, it must apply less force. "
the equation for calculating actual mechanical advantage is,(A) Actual Mechanical Advantage = Input Force/Output Force (B) Actual Mechanical Advantage = Input Distance/Output Distance (C) Actual Mechanical Advantage = Output Force/Input Force (D) Actual Mechanical Advantage = Output Distance/Input Distance,C,"How much a machine changes the input force is its mechanical advantage. Mechanical advantage is the ratio of the output force to the input force, so it can be represented by the equation: Actual Mechanical Advantage = Output force Input force Note that this equation represents the actual mechanical advantage of a machine. The actual mechanical advantage takes into account the amount of the input force that is used to overcome friction. The equation yields the factor by which the machine changes the input force when the machine is actually used in the real world. "
the equation for calculating ideal mechanical advantage is,(A) Ideal Mechanical Advantage = Input Force/Output Force (B) Ideal Mechanical Advantage = Input Distance/Output Distance (C) Ideal Mechanical Advantage = Output Force/Input Force (D) Ideal Mechanical Advantage = Output Distance/Input Distance,B,"It can be difficult to measure the input and output forces needed to calculate actual mechanical advantage. Its usually much easier to measure the input and output distances. These measurements can then be used to calculate the ideal mechanical advantage. The ideal mechanical advantage represents the multiplication of input force that would be achieved in the absence of friction. Therefore, it is greater than the actual mechanical advantage because all machines use up some work in overcoming friction. Ideal mechanical advantage is calculated with the equation: Ideal Mechanical Advantage = Input distance Output distance Compare this equation with the equation above for actual mechanical advantage. Notice how the input and output values are switched. This makes sense when you recall that when a machine increases force, it decreases distance and vice versa. You can watch a video about actual and ideal mechanical advantage at this link: http://video.goo Consider the simple ramp in Figure 16.12. A ramp can be used to raise an object up off the ground. The input distance is the length of the sloped surface of the ramp. The output distance is the height of the ramp, or the vertical distance the object is raised. Therefore, the ideal mechanical advantage of the ramp is: Ideal Mechanical Advantage = 6m =3 2m An ideal mechanical advantage of 3 means that the ramp ideally (in the absence of friction) multiplies the output force by a factor of 3. "
"the mechanical advantage of a machine may be less than, equal to, or greater than 1.",(A) true (B) false,A,"As you read above, some machines increase the force put into the machine, while other machines increase the distance over which the force is applied. Still other machines change only the direction of the force. Which way a machine works affects its mechanical advantage. For machines that increase force including ramps, doorknobs, and nutcrackers the output force is greater than the input force. Therefore, the mechanical advantage is greater than 1. For machines that increase the distance over which force is applied, such as paddles and hammers, the output force is less than the input force. Therefore, the mechanical advantage is less than 1. For machines that change only the direction of the force, such as the rope systems on flagpoles, the output force is the same as the input force. Therefore, the mechanical advantage is equal to 1. "
types of mechanical waves include,(A) transverse waves (B) longitudinal waves (C) surface waves (D) all of the above,D,"There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. "
mechanical waves can travel through liquids and gases but not through solids.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
particles of the medium actually travel along with a mechanical wave.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
in which type of wave do particles of the medium move in small circles?,(A) surface wave (B) transverse wave (C) longitudinal wave (D) none of the above,A,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
a longitudinal wave is a combination of a transverse wave and a surface wave.,(A) true (B) false,B,"A surface wave is a combination of a transverse wave and a longitudinal wave. A transverse wave is a wave in which particles of the medium move up and down perpendicular to the direction of the wave. A longitudinal wave is a wave in which particles of the medium move parallel to the direction of the wave. In a surface wave, particles of the medium move up and down as well as back and forth. This gives them an overall circular motion. You can see how the particles move in the Figure 1.1. Click image to the left or use the URL below. URL: "
atomic mass is an atoms number of,(A) protons (B) neutrons (C) protons plus electrons (D) protons plus neutrons,B,"Electrons have almost no mass. Instead, almost all the mass of an atom is in its protons and neutrons in the nucleus. The nucleus is very small, but it is densely packed with matter. The SI unit for the mass of an atom is the atomic mass unit (amu). One atomic mass unit equals the mass of a proton, which is about 1.7  10 24 g. Each neutron also has a mass of 1 amu. Therefore, the sum of the protons and neutrons in an atom is about equal to the atoms total mass in atomic mass units. Two numbers are commonly used to distinguish atoms: atomic number and mass number. Figure 5.4 shows how these numbers are usually written. The atomic number is the number of protons in an atom. This number is unique for atoms of each kind of element. For example, the atomic number of all helium atoms is 2. The mass number is the number of protons plus the number of neutrons in an atom. For example, most atoms of helium have 2 neutrons, so their mass number is 2 + 2 = 4. This mass number means that an atom of helium has a mass of about 4 amu. Problem Solving Problem: An atom has an atomic number of 12 and a mass number of 24. How many protons and neutrons does the atom have? Solution: The number of protons is the same as the atomic number, or 12. The number of neutrons is equal to the mass number minus the atomic number, or 24 12 = 12. You Try It! Problem: An atom has an atomic number of 8 and a mass number of 16. How many neutrons does it have? What is the atoms mass in atomic mass units? "
elements in a given period of mendeleevs table have similar properties.,(A) true (B) false,B,"You can see how Mendeleev organized the elements in Figure 6.2. From left to right across each row, elements are arranged by increasing atomic mass. Mendeleev discovered that if he placed eight elements in each row and then continued on to the next row, the columns of the table would contain elements with similar properties. He called the columns groups. They are sometimes called families, because elements within a group are similar but not identical to one another, like people in a family. Mendeleevs table of the elements is called a periodic table because of its repeating pattern. Anything that keeps repeating is referred to as periodic. Other examples of things that are periodic include the monthly phases of the moon and the daily cycle of night and day. The term period refers to the interval between repetitions. In a periodic table, the periods are the rows of the table. In Mendeleevs table, each period contains eight elements, and then the pattern repeats in the next row. "
"in mendeleevs table, how many elements are there in each period?",(A) 4 (B) 8 (C) 12 (D) 18,B,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
only some of the unknown elements that mendeleev predicted were ever discovered.,(A) true (B) false,B,"Did you notice the blanks in Mendeleevs table? They are spaces that Mendeleev left blank for elements that had not yet been discovered when he created his table. He predicted that these missing elements would eventually be discovered. Based on their position in the table, he even predicted their properties. For example, he predicted a missing element in row 5 of group III. He also predicted that the missing element would have an atomic mass of 68 and be a relatively soft metal like other elements in this group. Scientists searched for the missing element, and they found it just a few years later. They named the new element gallium. Scientists searched for the other missing elements in Mendeleevs table and eventually found all of them. An important measure of a good model is its ability to make accurate predictions. This makes it a useful model. Clearly, Mendeleevs periodic table was a useful model. It helped scientists discover new elements and made sense of those that were already known. "
the lattice-like structure of a metal consists of negative metal ions in a sea of electrons.,(A) true (B) false,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
properties of metals that are possible because of their freely moving electrons include the ability to,(A) conduct electricity (B) bend without breaking (C) form hydrogen bonds (D) two of the above,D,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
a metallic bond forms when one metal atom shares a pair of electrons with another metal atom.,(A) true (B) false,B,"A metallic bond is the force of attraction between a positive metal ion and the valence electrons it shares with other ions of the metal. The positive ions form a lattice-like structure. You can see an example in Figure 7.13. (For an animated version, go to the URL below.) The ions are held together in the lattice by bonds with the valence electrons around them. These valence electrons include their own and those of other ions. Why do metallic bonds form? Recall that metals ""want"" to give up their valence electrons. This means that their valence electrons move freely. The electrons form a ""sea"" of negative charge surrounding the positive ions. MEDIA Click image to the left or use the URL below. URL: "
metallic bonds form only between atoms of two or more different metals.,(A) true (B) false,B,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
in the lattice-like structure of a metal,(A) metal ions can move freely (B) valence electrons are in fixed positions (C) pairs of ions and electrons can move freely (D) none of the above,D,"The valence electrons surrounding metal ions are constantly moving. This makes metals good conductors of electricity. The lattice-like structure of metal ions is strong but quite flexible. This allows metals to bend without breaking. Metals are both ductile (can be shaped into wires) and malleable (can be shaped into thin sheets). Q: Look at the metalworker in the Figure 1.2. Hes hammering a piece of hot iron in order to shape it. Why doesnt the iron crack when he hits it? A: The iron ions can move within the sea of electrons around them. They can shift a little closer together or farther apart without breaking the metallic bonds between them. Therefore, the metal can bend rather than crack when the hammer hits it. "
which of the following elements form(s) metallic bonds?,(A) iron (B) oxygen (C) carbon (D) two of the above,A,"Metallic bonds are forces of attraction between positive metal ions and the valence electrons that are constantly moving around them (see the Figure 1.1). The valence electrons include their own and those of other, nearby ions of the same metal. The valence electrons of metals move freely in this way because metals have relatively low electronegativity, or attraction to electrons. The positive metal ions form a lattice-like structure held together by all the metallic bonds. Click image to the left or use the URL below. URL:  Q: Why do metallic bonds form only in elements that are metals? Why dont similar bonds form in elements that are nonmetals? A: Metal atoms readily give up valence electrons and become positive ions whenever they form bonds. When nonmetals bond together, the atoms share valence electrons and do not become ions. For example, when oxygen atoms bond together they form oxygen molecules in which two oxygen atoms share two pairs of valence electrons equally, so neither atom becomes charged. "
which of the following elements is not a metalloid?,(A) arsenic (B) boron (C) carbon (D) gemanium,C,"Groups 13-16 each contain one or more metalloids. These groups are shown in Figure 6.12. Group 13 is called the boron group. The only metalloid in this group is boron (B). The other four elements are metals. All group 13 elements have three valence electrons and are fairly reactive. All are solids at room temperature. Group 14 is called the carbon group. Carbon (C) is a nonmetal. The next two elements are metalloids, and the final two are metals. All the elements in the carbon group have four valence electrons. They are not very reactive. All are solids at room temperature. Group 15 is called the nitrogen group. The first two elements in this group are nonmetals. These are followed by two metalloids and one metal. All the elements in the nitrogen group have five valence electrons, but they vary in their reactivity. Nitrogen (N) in not reactive at all. Phosphorus (P), in contrast, is quite reactive. In fact, it is found naturally only in combination with other substances. Nitrogen is a gas at room temperature. The other group 15 elements are solids. Group 16 is called the oxygen group. The first three elements in this group are nonmetals. They are followed by one metalloid and one metal. All the elements in the oxygen group have six valence electrons, and all are "
the metalloid class is the smallest class of elements.,(A) true (B) false,A,"Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between metals and nonmetals in terms of their properties. Q: How does the position of an element in the periodic table influence its properties? A: Elements are arranged in the periodic table by their atomic number, which is the number of protons in their atoms. Atoms are neutral in electric charge, so they always have the same number of electrons as protons. It is the number of electrons in the outer energy level of atoms that determines most of the properties of elements. "
how many valence electrons do metalloids have?,(A) 1–2 (B) 2–4 (C) 3–6 (D) 6–8,C,"How metalloids behave in chemical interactions with other elements depends mainly on the number of electrons in the outer energy level of their atoms. Metalloids have from three to six electrons in their outer energy level. Boron, pictured in the Figure 1.1, is the only metalloid with just three electrons in its outer energy level. It tends to act like metals by giving up its electrons in chemical reactions. Metalloids with more than four electrons in their outer energy level (arsenic, antimony, and tellurium) tend to act like nonmetals by gaining electrons in chemical reactions. Those with exactly four electrons in their outer energy level (silicon and germanium) may act like either metals or nonmetals, depending on the other elements in the reaction. "
metalloids are generally,(A) dull (B) brittle (C) ductile (D) malleable,B,"Most metalloids have some physical properties of metals and some physical properties of nonmetals. For example, metals are good conductors of both heat and electricity, whereas nonmetals generally cannot conduct heat or electricity. And metalloids? They fall between metals and nonmetals in their ability to conduct heat, and if they can conduct electricity, they usually can do so only at higher temperatures. Metalloids that can conduct electricity at higher temperatures are called semiconductors. Silicon is an example of a semiconductor. It is used to make the tiny electric circuits in computer chips. You can see a sample of silicon and a silicon chip in the Figure 1.2. Metalloids tend to be shiny like metals but brittle like nonmetals. Because they are brittle, they may chip like glass or crumble to a powder if struck. Other physical properties of metalloids are more variable, including their boiling and melting points, although all metalloids exist as solids at room temperature. Click image to the left or use the URL below. URL: "
some metalloids are liquids at room temperature.,(A) true (B) false,B,"Most metalloids have some physical properties of metals and some physical properties of nonmetals. For example, metals are good conductors of both heat and electricity, whereas nonmetals generally cannot conduct heat or electricity. And metalloids? They fall between metals and nonmetals in their ability to conduct heat, and if they can conduct electricity, they usually can do so only at higher temperatures. Metalloids that can conduct electricity at higher temperatures are called semiconductors. Silicon is an example of a semiconductor. It is used to make the tiny electric circuits in computer chips. You can see a sample of silicon and a silicon chip in the Figure 1.2. Metalloids tend to be shiny like metals but brittle like nonmetals. Because they are brittle, they may chip like glass or crumble to a powder if struck. Other physical properties of metalloids are more variable, including their boiling and melting points, although all metalloids exist as solids at room temperature. Click image to the left or use the URL below. URL: "
metalloids fall between metals and nonmetals in the periodic table.,(A) true (B) false,A,"Groups 13-16 of the periodic table (orange in the Figure 1.1) are the only groups that contain elements classified as metalloids. Unlike other groups of the periodic table, which contain elements in just one class, groups 13-16 contain elements in at least two different classes. In addition to metalloids, they also contain metals, nonmetals, or both. Groups 13-16 fall between the transition metals (in groups 3-12) and the nonmetals called halogens (in group 17). "
metals are the largest of the three classes of elements.,(A) true (B) false,A,"Metals are elements that can conduct electricity. They are one of three classes of elements (the other two classes are nonmetals and metalloids). Metals are by far the largest of the three classes. In fact, most elements are metals. All of the elements on the left side and in the middle of the periodic table, except for hydrogen, are metals. There are several different types of metals, including alkali metals in group 1 of the periodic table, alkaline Earth metals in group 2, and transition metals in groups 3-12. The majority of metals are transition metals. "
properties of most metals include,(A) high melting point (B) ability to conduct heat (C) shiny appearance (D) all of the above,D,"Elements in the same class share certain basic similarities. In addition to conducting electricity, many metals have several other shared properties, including those listed below. Metals have relatively high melting points. This explains why all metals except for mercury are solids at room temperature. Most metals are good conductors of heat. Thats why metals such as iron, copper, and aluminum are used for pots and pans. Metals are generally shiny. This is because they reflect much of the light that strikes them. The mercury pictured above is very shiny. The majority of metals are ductile. This means that they can be pulled into long, thin shapes, like the aluminum electric wires pictured in the Figure 1.1. Metals tend to be malleable. This means that they can be formed into thin sheets without breaking. An example is aluminum foil, also pictured in the Figure 1.1. Q: The defining characteristic of metals is their ability to conduct electricity. Why do you think metals have this property? A: The properties of metalsas well as of elements in the other classesdepend mainly on the number and arrangement of their electrons. "
some metals are gases at room temperature.,(A) true (B) false,B,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
the properties of metals depend mainly on their number and arrangement of neutrons.,(A) true (B) false,B,"Metalloids are the smallest class of elements. (The other two classes of elements are metals and nonmetals). There are just six metalloids. In addition to silicon, they include boron, germanium, arsenic, antimony, and tellurium. Metalloids fall between metals and nonmetals in the periodic table. They also fall between metals and nonmetals in terms of their properties. Q: How does the position of an element in the periodic table influence its properties? A: Elements are arranged in the periodic table by their atomic number, which is the number of protons in their atoms. Atoms are neutral in electric charge, so they always have the same number of electrons as protons. It is the number of electrons in the outer energy level of atoms that determines most of the properties of elements. "
electromagnetic waves vary in their,(A) speed (B) frequency (C) wavelength (D) two of the above,D,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
the electromagnetic spectrum is defined as the full range of colors of visible light.,(A) true (B) false,B,"Visible light is the part of the electromagnetic spectrum (Figure 23.3) that humans can see. Visible light includes all the colors of the rainbow. Each color is determined by its wavelength. Visible light ranges from violet wavelengths of 400 nanometers (nm) through red at 700 nm. There are parts of the electromagnetic spectrum that humans cannot see. This radiation exists all around you. You just cant see it! Every star, including our Sun, emits radiation of many wavelengths. Astronomers can learn a lot from studying the details of the spectrum of radiation from a star. Many extremely interesting objects cant be seen with the unaided eye. Astronomers use telescopes to see objects at wavelengths all across the electromagnetic spectrum. Some very hot stars emit light primarily at ultraviolet wavelengths. There are extremely hot objects that emit X-rays and even gamma rays. Some very cool stars shine mostly in the infrared light wavelengths. Radio waves come from the faintest, most distant objects. To learn more about stars spectra, visit "
microwaves have lower frequencies than other radio waves.,(A) true (B) false,B,"The shortest wavelength, highest frequency radio waves are called microwaves (see Figure 21.7). Microwaves have more energy than other radio waves. Thats why they are useful for heating food in microwave ovens. Microwaves have other important uses as well, including cell phone transmissions and radar, which is a device for determining the presence and location of an object by measuring the time for the echo of a radio wave to return from it and the direction from which it returns. These uses are described in Figure 21.10. You can learn more about microwaves and their uses in the video at this URL:  (3:23). MEDIA Click image to the left or use the URL below. URL: "
microwaves are used for,(A) heating food (B) cell phone transmissions (C) radar (D) all of the above,D,"Find the microwave in the Figure 1.1. A microwave is an electromagnetic wave with a relatively long wavelength and low frequency. Microwaves are often classified as radio waves, but they have higher frequencies than other radio waves. With higher frequencies, they also have more energy. Thats why microwaves are useful for heating food in microwave ovens. Microwaves have other important uses as well, including cell phone transmissions and radar. These uses are described below. Click image to the left or use the URL below. URL: "
microwave signals can be interrupted by buildings and other obstructions.,(A) true (B) false,A,"Cell phone signals are carried through the air as microwaves. You can see how this works in the Figure 1.2. A cell phone encodes the sounds of the callers voice in microwaves by changing the frequency of the waves. This is called frequency modulation. The encoded microwaves are then sent from the phone through the air to a cell tower. From the cell tower, the waves travel to a switching center. From there they go to another cell tower and from the tower to the receiver of the person being called. The receiver changes the encoded microwaves back to sounds. Q: Cell towers reach high above the ground. Why do you think such tall towers are used? A: Microwaves can be interrupted by buildings and other obstructions, so cell towers must be placed high above the ground to prevent the interruption of cell phone signals. "
radar is used for,(A) computing the speed of vehicles (B) detecting air traffic (C) tracking storms (D) all of the above,D,"Radar stands for Radio Detection and Ranging (Figure 1.2). A transmitter sends out radio waves that bounce off the nearest object and then return to a receiver. Weather radar can sense many characteristics of precipitation: its location, motion, intensity, and the likelihood of future precipitation. Doppler radar can also track how fast the precipitation falls. Radar can outline the structure of a storm and can be used to estimate its possible effects. Radar view of a line of thunderstorms. "
the shape of a mirrors surface determines the type of image that it forms.,(A) true (B) false,A,"Mirrors are usually made of glass with a shiny metal backing that reflects all the light that strikes it. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image the mirror forms. For example, the image may be real or virtual. A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go behind a mirror, so a virtual image doesnt really exist. It just appears to exist to the human eye and brain. "
a real image,(A) forms in front of a mirror (B) forms where rays of light actually meet (C) is always smaller than the reflected object (D) two of the above,D,"A mirror is typically made of glass with a shiny metal backing that reflects all the light that strikes it. When a mirror reflects light, it forms an image. An image is a copy of an object that is formed by reflection or refraction. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image it forms. For example, some mirrors form real images, and other mirrors form virtual images. Whats the difference between real and virtual images? A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go through the mirror to the other side, so a virtual image doesnt really exist. It just appears to exist to the human brain. Q: Look back at the image of the girl pointing at her image in the mirror. Which type of image is it, real or virtual? A: The image of the girl is a virtual image. It appears to be on the other side of the mirror from the girl. "
a virtual image,(A) appears to be behind the mirror (B) doesn’t really exist (C) is always larger than the reflected object (D) two of the above,D,"A mirror is typically made of glass with a shiny metal backing that reflects all the light that strikes it. When a mirror reflects light, it forms an image. An image is a copy of an object that is formed by reflection or refraction. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image it forms. For example, some mirrors form real images, and other mirrors form virtual images. Whats the difference between real and virtual images? A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go through the mirror to the other side, so a virtual image doesnt really exist. It just appears to exist to the human brain. Q: Look back at the image of the girl pointing at her image in the mirror. Which type of image is it, real or virtual? A: The image of the girl is a virtual image. It appears to be on the other side of the mirror from the girl. "
the type of mirror in question 6 always forms real images.,(A) true (B) false,B,"Mirrors are usually made of glass with a shiny metal backing that reflects all the light that strikes it. Mirrors may have flat or curved surfaces. The shape of a mirrors surface determines the type of image the mirror forms. For example, the image may be real or virtual. A real image forms in front of a mirror where reflected light rays actually meet. It is a true image that could be projected on a screen. A virtual image appears to be on the other side of the mirror. Of course, reflected rays dont actually go behind a mirror, so a virtual image doesnt really exist. It just appears to exist to the human eye and brain. "
the type of mirror in question 8 always forms life-sized images.,(A) true (B) false,B,"The mirror in the opening photo is a plane mirror. This is the most common type of mirror. It has a flat reflective surface and forms only virtual images. The image formed by a plane mirror is also right-side up and life sized. But something is different about the image compared with the real object in front of the mirror. Left and right are reversed. Look at the girl brushing her teeth in the Figure 1.1. She is using her left hand to brush her teeth, but her image (on the left) appears to be brushing her teeth with the right hand. All plane mirrors reverse left and right in this way. The term mirror image refers to how left and right are reversed in an image compared with the object. "
which statement about convex mirrors is true?,(A) They curve outward like the outside of a bowl (B) They form only real images (C) They form only enlarged images (D) two of the above,A,"The other type of curved mirror, a convex mirror, is shaped like the outside of a bowl. This type of mirror forms only virtual images. The image is always right-side up and smaller than the actual object, which makes the object appear farther away than it really is. You can see how a convex mirror forms an image in Figure 22.14 and in the animation at the URL below. Because of their shape, convex mirrors can gather and reflect light from a wide area. This is why they are used as side mirrors on cars. They give the driver a wider view of the area around the vehicle than a plane mirror would. "
the modern periodic table is based on mendeleevs earlier periodic table.,(A) true (B) false,A,"A periodic table is still used today to organize the elements. You can see a simple version of the modern periodic table in the Figure 1.1. The modern table is based on Mendeleevs table, except the modern table arranges the elements by increasing atomic number instead of atomic mass. Atomic number is the number of protons in an atom, and this number is unique for each element. The modern table has more elements than Mendeleevs table because many elements have been discovered since Mendeleevs time. "
each element has a unique atomic number.,(A) true (B) false,A,"The number of protons per atom is always the same for a given element. However, the number of neutrons may vary, and the number of electrons can change. "
how many groups are there in the modern periodic table?,(A) 7 (B) 8 (C) 12 (D) 18,B,"Columns of the modern table are called groups, as they are in Mendeleevs table. However, the modern table has many more groups18 compared with just 8 in Mendeleevs table. Elements in the same group have similar properties. For example, all elements in group 18 are colorless, odorless gases, such as neon (Ne). (Neon is the element inside the light in opening photo C.) In contrast, all elements in group 1 are very reactive solids. They react explosively with water, as you can see in the video and Figure 1.2. Click image to the left or use the URL below. URL:  The alkali metal sodium (Na) reacting with water. "
all the periods of the modern periodic table contain the same number of elements.,(A) true (B) false,B,"Rows of the modern table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. In each period, elements change from metals on the left side of the table, to metalloids, and then to nonmetals on the right. Figure 6.4 shows this for period 4. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements. Periods 6 and 7, in contrast, are so long that some of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary symbols, such as Uub. Many of these elements have only recently been shown to exist. Elements 114 and 116 were added to the table in 2011. Four more elements (113, 115, 117, and 118) were approved for addition in December 2015 and will be named at some later date. "
the number of each period in the modern periodic table represents the number of,(A) energy levels containing electrons (B) electrons in each energy level (C) protons plus neutrons in the nucleus (D) none of the above,A,"Rows of the modern periodic table are called periods, as they are in Mendeleevs table. From left to right across a period, each element has one more proton than the element before it. Some periods in the modern periodic table are longer than others. For example, period 1 contains only two elements: hydrogen (H) and helium (He). In contrast, periods 6 and 7 are so long that many of their elements are placed below the main part of the table. They are the elements starting with lanthanum (La) in period 6 and actinium (Ac) in period 7. Some elements in period 7 have not yet been named. They are represented by temporary three-letter symbols, such as Uub. The number of each period represents the number of energy levels that have electrons in them for atoms of each element in that period. Q: Find calcium (Ca) in the Figure 1.1. How many energy levels have electrons in them for atoms of calcium? A: Calcium is in period 4, so its atoms have electrons in them for the first four energy levels. "
"in covalent compounds, elements are held together by the force of attraction between oppositely charged atoms.",(A) true (B) false,B,A covalent bond is the force of attraction that holds together two atoms that share a pair of valence electrons. The shared electrons are attracted to the nuclei of both atoms. This forms a molecule consisting of two or more atoms. Covalent bonds form only between atoms of nonmetals. 
covalent compounds form structures called crystals.,(A) true (B) false,B,"Many compounds form molecules, but ionic compounds form crystals instead. A crystal consists of many alternating positive and negative ions bonded together in a matrix. Look at the crystal of sodium chloride (NaCl) in the Figure bonds. Sodium chloride crystals are cubic in shape. Other ionic compounds may have crystals with different shapes. "
prefixes may be used in the name of a molecular compound to represent the numbers of each atom in a molecule of the compound. which prefix represents five atoms?,(A) tetra- (B) tri- (C) hexa- (D) penta-,C,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
which of the following is a correct rule for naming molecular compounds?,(A) The name of the element closer to the left side of the periodic table comes first (B) The name of the element closer to the right side of the periodic table comes first (C) The name of the element closer to the bottom of the periodic table comes first (D) The name of the element closer to the top of the periodic table comes first,A,"To name simple covalent compounds, follow these rules: Start with the name of the element closer to the left side of the periodic table. Follow this with the name of element closer to the right of the periodic table. Give this second name the suffix -ide. Use prefixes to represent the numbers of the different atoms in each molecule of the compound. The most commonly used prefixes are shown in the Table 1.1. Number 1 2 3 4 5 6 Prefix mono- (or none) di- tri- tetra- penta- hexa- Q: What is the name of the compound that contains three oxygen atoms and two nitrogen atoms? A: The compound is named dinitrogen trioxide. Nitrogen is named first because it is farther to the left in the periodic table than oxygen. Oxygen is given the -ide suffix because it is the second element named in the compound. The prefix di- is added to nitrogen to show that there are two atoms of nitrogen in each molecule of the compound. The prefix tri- is added to oxygen to show that there are three atoms of oxygen in each molecule. In the chemical formula for a covalent compound, the numbers of the different atoms in a molecule are represented by subscripts. For example, the formula for the compound named carbon dioxide is CO2 . Q: What is the chemical formula for dinitrogen trioxide? A: The chemical formula is N2 O3 . "
which of the following is a property of most molecular compounds?,(A) ability to dissolve in water (B) ability to burn easily (C) ability to conduct electricity (D) very high boiling point,B,"Covalent compounds have different properties than ionic compounds because of their bonds. Covalent compounds exist as individual molecules rather than crystals. It takes less energy for individual molecules than ions in a crystal to pull apart. As a result, covalent compounds have lower melting and boiling points than ionic compounds. Many are gases or liquids at room temperature. Covalent compounds have shared electrons. These are not free to move like the transferred electrons of ionic compounds. This makes covalent compounds poor conductors of electricity. Many covalent compounds also do not dissolve in water as all ionic compounds do. "
factors that determine an objects momentum include its,(A) mass (B) velocity (C) acceleration (D) two of the above,D,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
all objects with mass have momentum.,(A) true (B) false,B,"What if a friend asked you to play catch with a bowling ball, like the one pictured in Figure 14.10? Hopefully, you would refuse to play! A bowling ball would be too heavy to catch without risk of injury assuming you could even throw it. Thats because a bowling ball has a lot of mass. This gives it a great deal of momentum. Momentum is a property of a moving object that makes the object hard to stop. It equals the objects mass times its velocity. It can be represented by the equation: Momentum = Mass  Velocity This equation shows that momentum is directly related to both mass and velocity. An object has greater momentum if it has greater mass, greater velocity, or both. For example, a bowling ball has greater momentum than a softball when both are moving at the same velocity because the bowling ball has greater mass. However, a softball moving at a very high velocity say, 100 miles an hour would have greater momentum than a slow-rolling bowling ball. If an object isnt moving at all, it has no momentum. Thats because its velocity is zero, and zero times anything is zero. "
"to calculate an objects momentum, you would use the formula",(A) momentum = mass x acceleration (B) momentum = mass x velocity (C) momentum = mass/acceleration (D) momentum = mass/velocity,B,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
which football player has greater momentum?,(A) Ted: mass = 60 kg (B) velocity = 20 m/s (C) b Todd: mass = 80 kg (D) velocity = 17 m/s (E) c Tom: mass = 90 kg (F) velocity = 15 m/s (G) d Tim: mass = 100 kg (H) velocity = 12 m/s,B,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
which football players in question 7 have the same momentum?,(A) Ted and Todd (B) Todd and Tom (C) Ted and Tim (D) none of the above,C,"Momentum can be calculated by multiplying an objects mass in kilograms (kg) by its velocity in meters per second (m/s). For example, assume that a golf ball has a mass of 0.05 kg. If the ball is traveling at a velocity of 50 m/s, its momentum is: Momentum = 0.05 kg  50 m/s = 2.5 kg  m/s Note that the SI unit for momentum is kgm/s. Problem Solving Problem: What is the momentum of a 40-kg child who is running straight ahead with a velocity of 2 m/s? Solution: The child has momentum of: 40 kg  2 m/s = 80 kgm/s. You Try It! Problem: Which football player has greater momentum? Player A: mass = 60 kg; velocity = 2.5 m/s Player B: mass = 65 kg; velocity = 2.0 m/s "
"the faster an object is moving, the harder it is to stop.",(A) true (B) false,A,"When skater 2 runs into skater 1, hes going faster than skater 1 so he has more momentum. Momentum is a property of a moving object that makes it hard to stop. Its a product of the objects mass and velocity. At the moment of the collision, skater 2 transfers some of his momentum to skater 1, who shoots forward when skater 2 runs into him. Whenever an action and reaction such as this occur, momentum is transferred from one object to the other. However, the combined momentum of the objects remains the same. In other words, momentum is conserved. This is the law of conservation of momentum. Click image to the left or use the URL below. URL:  Click image to the left or use the URL below. URL: "
aspects of motion include speed and direction.,(A) true (B) false,A,"When both distance and direction are considered, motion can be represented by a vector. A vector is a measurement that has both size and direction. It may be represented by an arrow. If you are representing motion with an arrow, the length of the arrow represents distance, and the way the arrow points represents direction. The red arrows on the map in the Figure 1.1 are vectors for Jordans route from his house to the school and from the school to the post office. Q: How would you draw arrows to represent the distances and directions from the post office to the park on the map in the Figure 1.1? A: The vectors would look like this: "
"if you are riding on a bus with a friend, you can tell you are moving by observing the motion of",(A) your friend in the seat beside you (B) the bus driver at the front of the bus (C) objects like trees and houses outside the windows (D) two of the above,C,"Theres more to motion than objects simply changing position. Youll see why when you consider the following example. Assume that the school bus pictured in the Figure 1.2 passes by you as you stand on the sidewalk. Its obvious to you that the bus is moving, but what about to the children inside the bus? The bus isnt moving relative to them, and if they look at the other children sitting on the bus, they wont appear to be moving either. If the ride is really smooth, the children may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. Q: What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell that the bus is moving? A: Your frame of reference might be the trees and other stationary objects across the street. As the bus goes by, it momentarily blocks your view of these objects, and this helps you detect the bus motion. "
"in question 6, what is your frame of reference for detecting the motion of the bus?",(A) your friend (B) the bus driver (C) objects outside the windows (D) two of the above,C,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
"in question 6, the bus drivers frame of reference is the passenger directly behind him.",(A) true (B) false,B,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
"in question 6, the frame of reference of an outside observer of the bus might be a house across the street.",(A) true (B) false,A,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
"if you are sitting on a stationary bus, which frame of reference might may you think the bus has started moving?",(A) The car in the next lane starts moving (B) A passenger moves to the back of the bus (C) The bus driver turns to look through the windshield (D) none of the above,A,"Assume that a school bus, like the one in Figure 12.2, passes by as you stand on the sidewalk. Its obvious to you that the bus is moving. It is moving relative to you and the trees across the street. But what about to the children inside the bus? They arent moving relative to each other. If they look only at the other children sitting near them, they will not appear to be moving. They may only be able to tell that the bus is moving by looking out the window and seeing you and the trees whizzing by. This example shows that how we perceive motion depends on our frame of reference. Frame of reference refers to something that is not moving with respect to an observer that can be used to detect motion. For the children on the bus, if they use other children riding the bus as their frame of reference, they do not appear to be moving. But if they use objects outside the bus as their frame of reference, they can tell they are moving. What is your frame of reference if you are standing on the sidewalk and see the bus go by? How can you tell the bus is moving? The video at the URL below illustrates other examples of how frame of reference is related to motion. MEDIA Click image to the left or use the URL below. URL: "
people have been using sound to make music for thousands of years.,(A) true (B) false,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
there are a total of 50 different kinds of musical instruments.,(A) true (B) false,B,"There are three basic categories of musical instruments: percussion, wind, and stringed instruments. You can read in the Figure 1.1 how instruments in each category make sound and change pitch. Q: Can you name other instruments in each of the three categories of musical instruments? A: Other percussion instruments include drums and cymbals. Other wind instruments include trumpets and flutes. Other stringed instruments include guitars and harps. "
all musical instruments make sound by causing something to vibrate.,(A) true (B) false,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
"when instruments change the frequency of sound waves, the sound changes",(A) pitch (B) amplitude (C) loudness (D) all of the above,A,"People have been using sound to make music for thousands of years. They have invented many different kinds of musical instruments. Despite their diversity, however, musical instruments share certain similarities. All musical instruments create sound by causing matter to vibrate. The vibrations start sound waves moving through the air. Most musical instruments use resonance to amplify the sound waves and make the sounds louder. Resonance occurs when an object vibrates in response to sound waves of a certain frequency. In a musical instrument such as a drum, the whole instrument and the air inside it may vibrate when the head of the drum is struck. Most musical instruments have a way of changing the frequency of the sound waves they produce. This changes the pitch of the sounds, or how high or low the sounds seem to a listener. "
categories of musical instruments include,(A) wind instruments (B) stringed instruments (C) percussion instruments (D) all of the above,D,"There are three basic categories of musical instruments: percussion, wind, and stringed instruments. You can read in the Figure 1.1 how instruments in each category make sound and change pitch. Q: Can you name other instruments in each of the three categories of musical instruments? A: Other percussion instruments include drums and cymbals. Other wind instruments include trumpets and flutes. Other stringed instruments include guitars and harps. "
blowing into a clarinet starts vibrations in a thin wooden,(A) reed (B) bell (C) key (D) none of the above,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
what was the first step in the development of solar car technology?,(A) development of a model solar car (B) design of a solar panel (C) invention of the solar cell (D) launch of the World Solar Challenge,C,"New technologies such as 3-D printers often evolve slowly as new materials, designs, or processes are invented. Solar-powered cars are a good example. For several decades, researchers have been working on developing practical solar-powered cars. Why? Cars powered by sunlight have at least two important advantages over gas-powered cars. The energy they use is free and available almost everywhere, and they produce no pollution. The timeline in Table Milestone 1954: First modern solar cell 1955: First solar car 1983: First practical solar car 1987: First World Solar Challenge 2008: First Commercial solar car The first modern solar cell was invented in 1954 by a team of researchers at Bell Labs in the U.S. It could convert light energy to enough electricity to power devices. In 1955, William G. Cobb of General Motors demon- strated his 15-inch-long Sunmobile, the worlds first solar-powered automobile. Its tiny electric motor was powered by 12 solar cells on top of the car. In 1983, the first drivable solar car was created by Hans Tholstrup, a Danish inventor who was influenced by the earlier Sunmobile. Called the Quiet Achiever, Tholstrups car was driven 4000 km across Australia. However, its average speed was only 23 km/h, despite having more than 700 solar cells on its top panel. Inspired by his success with the Quiet Achiever, in 1987 Tholstrup launched the first World Solar Chal- lenge. This was the worlds first solar car race. The race is now held every other year. In that first race, the winner was General Motors Sunraycer, shown here. It had an average speed of 67 km/h. Its aerodynamic shape helped it achieve that speed. In 2008, the first commercial solar car was introduced. Called the Venturi Astrolab, it has a top speed of 120 km/h. To go this fast while using very little energy, it is built of ultra-light materials. Its oversized body protects the driver in case of collision and provides a lot of surface area for solar cells. Q: Why was the invention of the solar cell important to the evolution of solar car technology? A: The solar car could not exist without the solar cell. This invention provided a way to convert light energy to electricity that could be used to run a device such as a car. Q: The 1955 Sunmobile was just a model car. It was too small for people to drive. Why was it an important achievement in the evolution of solar car technology? A: The car wasnt practical, but it was a working solar car. It showed people that solar car technology is possible. It spurred others, including Hans Tholstrup, to work on solar cars that people could actually drive. Q: How have the World Solar Challenge races influenced the development of solar cars? A: The races have drawn a lot of attention to solar car development. The challenge of winning a race has also stimulated developers to keep improving the performance of solar cars so they can go faster and farther on solar power alone. "
technology may include,(A) materials (B) devices (C) processes (D) all of the above,D,"Technology is the application of knowledge to real-world problems. It includes methods and processes as well as devices like computers and cars. An example is the Bessemer process. It is a cheap method of making steel that was invented in the 1850s. It is just one of many technological advances that have occurred in manufacturing. Technology is also responsible for most of the major advances in agriculture, transportation, communications, and medicine. Clearly, technology has had a huge impact on people and society. It is hard to imagine what life would be like without it. Professionals in technology are generally called engineers. Most engineers have a strong background in physical science. There are many different careers in engineering. You can learn about some of them at the URLs below. "
atoms of all elements have neutrons in their nucleus.,(A) true (B) false,B,"A neutron is a particle inside the nucleus of an atom. It has no electric charge. Atoms of an element often have the same number of neutrons as protons. For example, most carbon atoms have six neutrons as well as six protons. This is also shown in Figure below . "
neutrons have a negative electrical charge.,(A) true (B) false,B,"Unlike protons and electrons, which are electrically charged, neutrons have no charge. In other words, they are electrically neutral. Thats why the neutrons in the diagram above are labeled n0 . The zero stands for zero charge. The mass of a neutron is slightly greater than the mass of a proton, which is 1 atomic mass unit (amu). (An atomic mass unit equals about 1.67  1027 kilograms.) A neutron also has about the same diameter as a proton, or 1.7 1017 meters. "
the mass of a neutron is close to the mass of,(A) an electron (B) a proton (C) the nucleus (D) none of the above,B,"Unlike protons and electrons, which are electrically charged, neutrons have no charge. In other words, they are electrically neutral. Thats why the neutrons in the diagram above are labeled n0 . The zero stands for zero charge. The mass of a neutron is slightly greater than the mass of a proton, which is 1 atomic mass unit (amu). (An atomic mass unit equals about 1.67  1027 kilograms.) A neutron also has about the same diameter as a proton, or 1.7 1017 meters. "
a neutron has about the same diameter as a proton.,(A) true (B) false,A,"Unlike protons and electrons, which are electrically charged, neutrons have no charge. In other words, they are electrically neutral. Thats why the neutrons in the diagram above are labeled n0 . The zero stands for zero charge. The mass of a neutron is slightly greater than the mass of a proton, which is 1 atomic mass unit (amu). (An atomic mass unit equals about 1.67  1027 kilograms.) A neutron also has about the same diameter as a proton, or 1.7 1017 meters. "
atoms of the same element may differ in their numbers of neutrons.,(A) true (B) false,A,"Some atoms of the same element may have different numbers of neutrons. For example, some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in number of neutrons are called isotopes. Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same chemical properties. Thats because they have the same numbers of protons and electrons. For a video explanation of isotopes, go to this URL:  MEDIA Click image to the left or use the URL below. URL: "
each neutron contains,(A) three quarks and three gluons (B) two up quarks and one down quark (C) two quarks and one gluon (D) two gluons and one quark,A,"A neutron is a particle inside the nucleus of an atom. It has no electric charge. Atoms of an element often have the same number of neutrons as protons. For example, most carbon atoms have six neutrons as well as six protons. This is also shown in Figure below . "
"without an unbalanced force acting on it, a moving object will",(A) keep moving (B) maintain a constant speed (C) keep going in the same direction (D) all of the above,D,"To change the motion of an object, inertia must be overcome by an unbalanced force acting on the object. The unbalanced force that starts Laurens cousins rolling along on the skateboard is applied by Lauren when she gives it a push. Once an object starts moving, inertia keeps it moving without any additional force being applied. In fact, it wont stop moving unless another unbalanced force opposes its motion. For example, Lauren can stop the rolling skateboard by moving to the other end and pushing in the opposite direction. Q: What if Lauren didnt stop the skateboard in this way? If it remained on a smooth, flat surface, would it just keep rolling forever? A: The inertia of the moving skateboard would keep it rolling forever if no other unbalanced force opposed its motion. However, another unbalanced force does act on the skateboard Q: What other force is acting on the skateboard? A: The other force is rolling friction between the skateboards wheels and the ground. The force of friction opposes the motion of the rolling skateboard and would eventually bring it to a stop without any help from Lauren. Friction opposes the motion of all moving objects, solike the skateboardall moving objects eventually stop moving even if no other forces oppose their motion. Later that day, Jonathan rode his skateboard and did some jumps. You can see him in the picture 1.2. When hes in the air, there is no rolling friction between his wheels and the ground, but another unbalanced force is acting on the skateboard and changing its motion. Q: What force is acting on the skateboard when it is in the air above the ground? And how will this force change the skateboards motion? A: The force of gravity is acting on the skateboard. It will pull the skateboard back down to the ground. Once its on the ground, friction will slow its motion. "
"if you dont try to stop a rolling skateboard, it will keep moving forever.",(A) true (B) false,B,"To change the motion of an object, inertia must be overcome by an unbalanced force acting on the object. The unbalanced force that starts Laurens cousins rolling along on the skateboard is applied by Lauren when she gives it a push. Once an object starts moving, inertia keeps it moving without any additional force being applied. In fact, it wont stop moving unless another unbalanced force opposes its motion. For example, Lauren can stop the rolling skateboard by moving to the other end and pushing in the opposite direction. Q: What if Lauren didnt stop the skateboard in this way? If it remained on a smooth, flat surface, would it just keep rolling forever? A: The inertia of the moving skateboard would keep it rolling forever if no other unbalanced force opposed its motion. However, another unbalanced force does act on the skateboard Q: What other force is acting on the skateboard? A: The other force is rolling friction between the skateboards wheels and the ground. The force of friction opposes the motion of the rolling skateboard and would eventually bring it to a stop without any help from Lauren. Friction opposes the motion of all moving objects, solike the skateboardall moving objects eventually stop moving even if no other forces oppose their motion. Later that day, Jonathan rode his skateboard and did some jumps. You can see him in the picture 1.2. When hes in the air, there is no rolling friction between his wheels and the ground, but another unbalanced force is acting on the skateboard and changing its motion. Q: What force is acting on the skateboard when it is in the air above the ground? And how will this force change the skateboards motion? A: The force of gravity is acting on the skateboard. It will pull the skateboard back down to the ground. Once its on the ground, friction will slow its motion. "
pressing down on one side of a skateboard causes it to turn toward the opposite side.,(A) true (B) false,A,"Coreys friend Jerod likes to skate on the flat banks at Newtons Skate Park. Thats Jerod in the Figure 1.3. As he reaches the top of a bank, he turns his skateboard to go back down. To change direction, he presses down with his heels on one edge of the skateboard. This causes the skateboard to turn in the opposite direction. "
"if you run into a curb on a skateboard, you will fall forward off your skateboard because there is an unbalanced force applied to your body.",(A) true (B) false,B,"Did you ever ride a skateboard? Even if you didnt, you probably know that to start a skateboard rolling over a level surface, you need to push off with one foot against the ground. Thats what Coreys friend Nina is doing in this picture 1.1. Do you know how to stop a skateboard once it starts rolling? Look how Ninas friend Laura does it in the Figure the skateboard. Even if Laura didnt try to stop the skateboard, it would stop sooner or later. Thats because theres also friction between the wheels and the pavement. Friction is a force that counters all kinds of motion. It occurs whenever two surfaces come into contact. "
isaac newton was the first person to observe the effects of gravity.,(A) true (B) false,B,"People have known about gravity for thousands of years. After all, they constantly experienced gravity in their daily lives. They knew that things always fall toward the ground. However, it wasnt until Sir Isaac Newton developed his law of gravity in the late 1600s that people really began to understand gravity. Newton is pictured in Figure 13.17. "
newton would agree that all objects on earth exert a gravitational pull on earth.,(A) true (B) false,A,"Newton was the first one to suggest that gravity is universal and affects all objects in the universe. Thats why his law of gravity is called the law of universal gravitation. Universal gravitation means that the force that causes an apple to fall from a tree to the ground is the same force that causes the moon to keep moving around Earth. Universal gravitation also means that while Earth exerts a pull on you, you exert a pull on Earth. In fact, there is gravity between you and every mass around you  your desk, your book, your pen. Even tiny molecules of gas are attracted to one another by the force of gravity. Newtons law had a huge impact on how people thought about the universe. It explains the motion of objects not only on Earth but in outer space as well. You can learn more about Newtons law of gravity in the video at this URL: "
newtons law of gravity was the first scientific law that applied to everything in the universe.,(A) true (B) false,A,"Newton was the first one to suggest that gravity is universal and affects all objects in the universe. Thats why Newtons law of gravity is called the law of universal gravitation. Universal gravitation means that the force that causes an apple to fall from a tree to the ground is the same force that causes the moon to keep moving around Earth. Universal gravitation also means that while Earth exerts a pull on you, you exert a pull on Earth. In fact, there is gravity between you and every mass around youyour desk, your book, your pen. Even tiny molecules of gas are attracted to one another by the force of gravity. Q: Newtons law of universal gravitation had a huge impact on how people thought about the universe. Why do you think it was so important? A: Newtons law was the first scientific law that applied to the entire universe. It explains the motion of objects not only on Earth but in outer space as well. "
"the equation that newtons developed to calculate the force of gravity between two gm1m 2 . in this equation, the letter g represents the objects is fg =",(A) force of gravity (B) combined masses of the objects (C) universal gravitational constant (D) none of the above,C,"Newtons second law of motion explains the weight of objects. Weight is a measure of the force of gravity pulling on an object of a given mass. Its the force (F) in the acceleration equation that was introduced above: a= F m This equation can also be written as: F = ma The acceleration due to gravity of an object equals 9.8 m/s2 , so if you know the mass of an object, you can calculate its weight as: F = m  9.8 m/s2 As this equation shows, weight is directly related to mass. As an objects mass increases, so does its weight. For example, if mass doubles, weight doubles as well. You can learn more about weight and acceleration at this URL: Problem Solving Problem: Daisy has a mass of 35 kilograms. How much does she weigh? Solution: Use the formula: F = m  9.8 m/s2 . F = 35 kg  9.8 m/s2 = 343.0 kg  m/s2 = 343.0 N You Try It! Problem: Daisys dad has a mass is 70 kg, which is twice Daisys mass. Predict how much Daisys dad weighs. Then calculate his weight to see if your prediction is correct. Helpful Hints The equation for calculating weight (F = m  a) works only when the correct units of measurement are used. Mass must be in kilograms (kg). Acceleration must be in m/s2 . Weight (F) is expressed in kgm/s2 or in newtons (N). "
what does the letter r represent in the equation in question 7?,(A) rotation (B) revolution (C) distance (D) none of the above,C,"The population growth rate is how fast a population is growing. The letter r stands for the growth rate. The growth rate equals the number of new members added to the population in a year for each 100 members already in the population. The growth rate includes new members added to the population and old members removed from the population. Births add new members to the population. Deaths remove members from the population. The formula for population growth rate is: r = b - d, where b = birth rate (number of births in 1 year per 100 population members) d = death rate (number of deaths in 1 year per 100 population members) If the birth rate is greater than the death rate, r is positive. This means that the population is growing bigger. For example, if b = 10 and d = 8, r = 2. This means that the population is growing by 2 individuals per year for every 100 members of the population. This may not sound like much, but its a fairly high rate of growth. A population growing at this rate would double in size in just 35 years! If the birth rate is less than the death rate, r is negative. This means that the population is becoming smaller. What do you think might cause this to happen? "
acceleration occurs whenever an object is acted on by an unbalanced force.,(A) true (B) false,A,"A change in an objects motionsuch as Xander speeding up on his scooteris called acceleration. Acceleration occurs whenever an object is acted upon by an unbalanced force. The greater the net force acting on the object, the greater its acceleration will be, but the mass of the object also affects its acceleration. The smaller its mass is, the greater its acceleration for a given amount of force. Newtons second law of motion summarizes these relationships. According to this law, the acceleration of an object equals the net force acting on it divided by its mass. This can be represented by the equation: Acceleration = Net force Mass or a = F m "
factors that affect the acceleration of an object include the,(A) net force acting on the object (B) object’s speed (C) object’s mass (D) two of the above,D,"Whenever an object speeds up, slows down, or changes direction, it accelerates. Acceleration occurs whenever an unbalanced force acts on an object. Two factors affect the acceleration of an object: the net force acting on the object and the objects mass. Newtons second law of motion describes how force and mass affect acceleration. The law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Acceleration = or a = Net force Mass F m Q: While Tony races along on his rollerblades, what net force is acting on the skates? A: Tony exerts a backward force against the ground, as you can see in the Figure 1.1, first with one skate and then with the other. This force pushes him forward. Although friction partly counters the forward motion of the skates, it is weaker than the force Tony exerts. Therefore, there is a net forward force on the skates. "
there is a direct relationship between acceleration and mass.,(A) true (B) false,B,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
increasing the force acting on an object increases its acceleration.,(A) true (B) false,A,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
"if the net force acting on an object increases by 50 percent, then the acceleration of the object will",(A) decrease by 50 percent (B) increase by 100 percent (C) stay the same (D) none of the above,D,"Newtons second law shows that there is a direct relationship between force and acceleration. The greater the force that is applied to an object of a given mass, the more the object will accelerate. For example, doubling the force on the object doubles its acceleration. The relationship between mass and acceleration, on the other hand, is an inverse relationship. The greater the mass of an object, the less it will accelerate when a given force is applied. For example, doubling the mass of an object results in only half as much acceleration for the same amount of force. Consider the example of a batter, like the boy in Figure 14.6. The harder he hits the ball, the greater will be its acceleration. It will travel faster and farther if he hits it with more force. What if the batter hits a baseball and a softball with the same amount of force? The softball will accelerate less than the baseball because the softball has greater mass. As a result, it wont travel as fast or as far as the baseball. "
"which equation shows the relationships among acceleration, mass, and net force?",(A) acceleration = net force x mass (B) acceleration =- net force/mass (C) acceleration = mass/net force (D) none of the above,B,"Newton determined that two factors affect the acceleration of an object: the net force acting on the object and the objects mass. The relationships between these two factors and motion make up Newtons second law of motion. This law states that the acceleration of an object equals the net force acting on the object divided by the objects mass. This can be represented by the equation: Net force , or Mass F a= m Acceleration = You can watch a video about how Newtons second law of motion applies to football at this URL: http://science36 "
forces always act in pairs.,(A) true (B) false,A,"Two forces may act on an object in the same direction. You can see an example of this in Figure 13.5. After the man on the left lifts up the couch, he will push the couch to the right with a force of 25 newtons. At the same time, the man to the right is pulling the couch to the right with a force of 20 newtons. When two forces act in the same direction, the net force is equal to the sum of the forces. This always results in a stronger force than either of the individual forces alone. In this case, the net force on the couch is 45 newtons to the right, so the couch will move to the right. You Try It! Problem: The boys in the drawing above are about to kick the soccer ball in opposite directions. What will be the net force on the ball? In which direction will the ball move? "
the reaction to an action is always,(A) equal in strength to the action (B) in the same direction as the action (C) in the opposite direction to the action (D) two of the above,D,"Newtons third law of motion states that every action has an equal and opposite reaction. This means that forces always act in pairs. First an action occurs, such as the skateboarders pushing together. Then a reaction occurs that is equal in strength to the action but in the opposite direction. In the case of the skateboarders, they move apart, and the distance they move depends on how hard they first pushed together. You can see other examples of actions and reactions in Figure 14.9. You can watch a video about actions and reactions at this URL:  You might think that actions and reactions would cancel each other out like balanced forces do. Balanced forces, which are also equal and opposite, cancel each other out because they act on the same object. Action and reaction forces, in contrast, act on different objects, so they dont cancel each other out and, in fact, often result in motion. For example, in Figure 14.9, the kangaroos action acts on the ground, but the grounds reaction acts on the kangaroo. As a result, the kangaroo jumps away from the ground. One of the action-reaction examples in the Figure 14.9 does not result in motion. Do you know which one it is? "
a stronger action always results in a stronger reaction.,(A) true (B) false,A,"The forces involved in actions and reactions can be represented with arrows. The way an arrow points shows the direction of the force, and the size of the arrow represents the strength of the force. Look at the skateboarders in the Figure 1.1. In the top row, the arrows represent the forces with which the skateboarders push against each other. This is the action. In the bottom row, the arrows represent the forces with which the skateboarders move apart. This is the reaction. Compare the top and bottom arrows. They point in different directions, but they are the same size. This shows that the reaction forces are equal and opposite to the action forces. "
action and reaction forces always cancel each other out.,(A) true (B) false,B,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
action and reaction forces always act on the same object.,(A) true (B) false,B,"Because action and reaction forces are equal and opposite, you might think they would cancel out, as balanced forces do. But you would be wrong. Balanced forces are equal and opposite forces that act on the same object. Thats why they cancel out. Action-reaction forces are equal and opposite forces that act on different objects, so they dont cancel out. In fact, they often result in motion. Think about Jerod again. He applies force with his foot to the ground, whereas the ground applies force to Jerod and the skateboard, causing them to move forward. Q: Actions and reactions occur all the time. Can you think of an example in your daily life? A: Heres one example. If you lean on something like a wall or your locker, you are applying force to it. The wall or locker applies an equal and opposite force to you. If it didnt, you would go right through it or else it would tip over. "
the lift off of a rocket is a(n),(A) combined force (B) action force (C) reaction force (D) two of the above,C,"A rocket is propelled into space by particles flying out of one end at high speed (see Figure 1.1). A rocket in space moves like a skater holding the fire extinguisher. Fuel is ignited in a chamber, which causes an explosion of gases. The explosion creates pressure that forces the gases out of the rocket. As these gases rush out the end, the rocket moves in the opposite direction, as predicted by Newtons Third Law of Motion. The reaction force of the gases on the rocket pushes the rocket forward. The force pushing the rocket is called thrust. Nothing would get into space without being thrust upward by a rocket. "
noble gases are the elements in group 17 of the periodic table.,(A) true (B) false,B,"Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why they are gases at room temperature. Radon, at the bottom of the group, is radioactive, so it constantly decays to other elements. Click image to the left or use the URL below. URL:  Q: Based on their position in the periodic table (Figure 1.1), how many valence electrons do you think noble gases have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the table above). Therefore, noble gases have eight valence electrons. "
noble gases are nonreactive elements.,(A) true (B) false,A,"Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL: "
noble gases include,(A) oxygen (B) nitrogen (C) argon (D) all of the above,C,"Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why they are gases at room temperature. Radon, at the bottom of the group, is radioactive, so it constantly decays to other elements. Click image to the left or use the URL below. URL:  Q: Based on their position in the periodic table (Figure 1.1), how many valence electrons do you think noble gases have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the table above). Therefore, noble gases have eight valence electrons. "
all noble gases are,(A) odorless (B) colorless (C) radioactive (D) two of the above,D,"Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL: "
noble gases have high boiling points.,(A) true (B) false,B,"Noble gases are nonreactive, nonmetallic elements in group 18 of the periodic table. As you can see in the periodic table below, noble gases include helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). All noble gases are colorless and odorless. They also have low boiling points, explaining why they are gases at room temperature. Radon, at the bottom of the group, is radioactive, so it constantly decays to other elements. Click image to the left or use the URL below. URL:  Q: Based on their position in the periodic table (Figure 1.1), how many valence electrons do you think noble gases have? A: The number of valence electrons starts at one for elements in group 1. It then increases by one from left to right across each period (row) of the periodic table for groups 1-2 and 13-18 (numbered 3-0 in the table above). Therefore, noble gases have eight valence electrons. "
examples of nonmetals include,(A) carbon (B) phosphorus (C) sulfur (D) all of the above,D,"Nonmetals are elements that do not conduct electricity. They are the second largest class of elements. Find the nonmetals in Figure 6.3. They are all the elements on the right side of the table that are color-coded green. Examples of nonmetals include helium (He), carbon (C), and oxygen (O). Nonmetals generally have properties that are the opposite of those of metals. They also tend to vary more in their properties than metals do. For example, nonmetals have relatively low boiling points, so many of them are gases at room temperature. But several nonmetals are solids, including carbon and phosphorus (P). One nonmetal, bromine (Br), is a liquid at room temperature. Generally, nonmetals are also poor conductors of heat. In fact, they may be used for insulation. For example, the down filling in a down jacket is mostly air, which consists mainly of nitrogen (N) and oxygen (O). These nonmetal gases are poor conductors of heat, so they keep body heat in and cold air out. Solid nonmetals are dull rather than shiny. They are also brittle rather than ductile or malleable. You can see examples of solid nonmetals in Figure 6.6. You can learn more about specific nonmetals with the interactive table at this URL: http://library.thinkquest.org/36 "
there are fewer nonmetals than there are elements in any other class.,(A) true (B) false,B,"Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right across each period (row) of the periodic table, each element has atoms with one more proton and one more electron than the element before it. How might this be related to the properties of nonmetals? A: Because nonmetals are on the right side of the periodic table, they have more electrons in their outer energy level than elements on the left side or in the middle of the periodic table. The number of electrons in the outer energy level of an atom determines many of its properties. "
properties of nonmetals include,(A) high boiling point (B) ability to conduct heat (C) dull appearance (D) none of the above,C,"As their name suggests, nonmetals generally have properties that are very different from the properties of metals. Properties of nonmetals include a relatively low boiling point, which explains why many of them are gases at room temperature. However, some nonmetals are solids at room temperature, including the three pictured above, and one nonmetalbromineis a liquid at room temperature. Other properties of nonmetals are illustrated and described in the Figure 1.1. "
all nonmetals are very reactive.,(A) true (B) false,B,"Group 18 elements are nonmetals called noble gases (see Figure 6.14). They are all colorless, odorless gases. Their outer energy level is also full, so they are the least reactive elements. In nature, they seldom combine with other substances. For a short video about the noble gases and their properties, go to this URL: "
nonmetals are located on the right side of the periodic table.,(A) true (B) false,A,"Nonmetals are elements that generally do not conduct electricity. They are one of three classes of elements (the other two classes are metals and metalloids.) Nonmetals are the second largest of the three classes after metals. They are the elements located on the right side of the periodic table. Q: From left to right across each period (row) of the periodic table, each element has atoms with one more proton and one more electron than the element before it. How might this be related to the properties of nonmetals? A: Because nonmetals are on the right side of the periodic table, they have more electrons in their outer energy level than elements on the left side or in the middle of the periodic table. The number of electrons in the outer energy level of an atom determines many of its properties. "
most of the elements that make up the human body are nonmetals.,(A) true (B) false,A,"An element is pure substance that cannot be broken down into other substances. Each element has a particular set of properties that, taken together, distinguish it from all other elements. Table 2.1 lists the major elements in the human body. As you can see, you consist mainly of the elements oxygen, carbon, and hydrogen. Element Oxygen Carbon Hydrogen Nitrogen Calcium Phosphorus Potassium Sulfur Percent of Body Mass 65 18 10 3 1.5 1.0 0.35 0.25 In your body, most elements are combined with other elements to form chemical compounds. A compound is a unique type of matter in which two or more elements are combined chemically in a certain ratio. For example, much of the oxygen and hydrogen in your body are combined in the chemical compound water, or H2O. "
the fuel used in nuclear power plants is,(A) krypton-92 (B) barium-141 (C) uranium-235 (D) none of the above,C,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
what is missing from the following nuclear equation for the fissioning of uranium-235? kr + ba + ? + energy 235 141,(A) 1 electron (B) 2 protons (C) 3 neutrons (D) 4 positrons,C,"The Figure 1.2 shows how nuclear fission of uranium-235 occurs. It begins when a uranium nucleus gains a neutron. This can happen naturally when a free neutron strikes it, or it can occur deliberately when a neutron is crashed into it in a nuclear power plant. In either case, the nucleus of uranium-235 becomes extremely unstable with the extra neutron. As a result, it splits into two smaller nuclei, krypton-92 and barium-141. The reaction also releases three neutrons and a great deal of energy. It can be represented by this nuclear equation: 235 U 92 141 + 1 neutron  92 36 Kr + 56 Ba + 3 neutrons + energy Note that the subscripts of the element symbols represent numbers of protons and the superscripts represent numbers of protons plus neutrons. "
"in a nuclear power plant, the energy from nuclear reactions is used to boil water.",(A) true (B) false,A,"Nuclear power plants, such as the one seen in Figure 1.2, use uranium, which is mined, processed, and then concentrated into fuel rods. When the uranium atoms in the fuel rods are hit by other extremely tiny particles, they split apart. The number of tiny particles allowed to hit the fuel rods needs to be controlled, or they would cause a dangerous explosion. The energy from a nuclear power plant heats water, which creates steam and causes a turbine to spin. The spinning turbine turns a generator, which in turn produces electricity. Many countries around the world use nuclear energy as a source of electricity. In the United States, a little less than 20% of electricity comes from nuclear energy. "
nuclear power plants do not produce air pollution.,(A) true (B) false,A,"Nuclear power is clean. It does not pollute the air. However, the use of nuclear energy does create other environ- mental problems. Uranium must be mined (Figure 1.3). The process of splitting atoms creates radioactive waste, which remains dangerous for thousands or hundreds of thousands of years. As yet, there is no long-term solution for storing this waste. The development of nuclear power plants has been on hold for three decades. Accidents at Three Mile Island and Chernobyl, Ukraine verified peoples worst fears about the dangers of harnessing nuclear power (Figure 1.4). Recently, nuclear power appeared to be making a comeback as society looked for alternatives to fossil fuels. After all, nuclear power emits no pollutants, including no greenhouse gases. But the 2011 disaster at the Fukushima Daiichi Nuclear Power Plant in Japan may have resulted in a new fear of nuclear power. The cause of the disaster was a 9.0 magnitude earthquake and subsequent tsunami, which compromised the plant. Although a total meltdown was averted, the plant experienced multiple partial meltdowns, core breaches, radiation releases, and cooling failures. The plant is scheduled for a complete cold shutdown before the end of 2011. Damaged building near the site of the Chernobyl disaster. Nuclear power is a controversial subject in California and most other places. Nuclear power has no pollutants including carbon emissions, but power plants are not always safe and the long-term disposal of wastes is a problem that has not yet been solved. The future of nuclear power is murky. "
nuclear energy is a renewable energy resource.,(A) true (B) false,B,"Fossil fuels and nuclear energy are nonrenewable energy resources. People worldwide depend far more on these energy sources than any others. Figure 25.10 shows the worldwide consumption of energy sources by type in 2010. Nonrenewable energy sources accounted for 83 percent of the total energy used. Fossil fuels and the uranium needed for nuclear power will soon be used up if we continue to consume them at these rates. Using fossil fuels and nuclear energy creates other problems as well. The burning of fossil fuels releases carbon dioxide into the atmosphere. This is one of the major greenhouse gases causing global climate change. Nuclear power creates another set of problems, including the disposal of radioactive waste. "
nuclear fusion occurs inside,(A) stars (B) planets (C) nuclear power plants (D) two of the above,A,"Nuclear fusion of hydrogen to form helium occurs naturally in the sun and other stars. It takes place only at extremely high temperatures. Thats because a great deal of energy is needed to overcome the force of repulsion between positively charged nuclei. The suns energy comes from fusion in its core, where temperatures reach millions of Kelvin (see Figure 11.16). "
fusion of two hydrogen nuclei produces,(A) a helium nucleus (B) a neutron (C) energy (D) all of the above,D,"In nuclear fusion, two or more small nuclei combine to form a single, larger nucleus. You can see an example in the Figure 1.1. In this example, nuclei of two hydrogen isotopes (tritium and deuterium) fuse to form a helium nucleus. A neutron and a tremendous amount of energy are also released. "
nuclear fusion produces dangerous radioactive wastes.,(A) true (B) false,B,"In the U.S., the majority of electricity is produced by burning coal or other fossil fuels. This causes air pollution, acid rain, and global warming. Fossil fuels are also limited and may eventually run out. Like fossil fuels, radioactive elements are limited. In fact, they are relatively rare, so they could run out sooner rather than later. On the other hand, nuclear fission does not release air pollution or cause the other environmental problems associated with burning fossil fuels. This is the major advantage of using nuclear fission as a source of energy. The main concern over the use of nuclear fission is the risk of radiation. Accidents at nuclear power plants can release harmful radiation that endangers people and other living things. Even without accidents, the used fuel that is left after nuclear fission reactions is still radioactive and very dangerous. It takes thousands of years for it to decay until it no longer releases harmful radiation. Therefore, used fuel must be stored securely to people and other living things. You can learn more about the problem of radioactive waste at this URL: "
the fuel needed for nuclear fusion is plentiful.,(A) true (B) false,A,"Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioiso- topes, nuclear fusion involves hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the worlds people for a very long time. Unfortunately, using energy from nuclear fusion is far from a reality. Scientists are a long way from developing the necessary technology. One problem is raising temperatures high enough for fusion to take place. Another problem is that matter this hot exists only in the plasma state. There are no known materials that can contain plasma, although a magnet might be able to do it. Thats because plasma consists of ions and responds to magnetism. You can learn more about research on nuclear fusion at the URL below. "
scientists are a long way from developing the technology needed to use nuclear fusion to produce electricity.,(A) true (B) false,A,"Scientists are searching for ways to create controlled nuclear fusion reactions on Earth. Their goal is develop nuclear fusion power plants, where the energy from fusion of hydrogen nuclei can be converted to electricity. How this might work is shown in Figure 11.17. The use of nuclear fusion for energy has several pros. Unlike nuclear fission, which involves dangerous radioiso- topes, nuclear fusion involves hydrogen and helium. These elements are harmless. Hydrogen is also very plentiful. There is a huge amount of hydrogen in ocean water. The hydrogen in just a gallon of water could produce as much energy by nuclear fusion as burning 1,140 liters (300 gallons) of gasoline! The hydrogen in the oceans would generate enough energy to supply all the worlds people for a very long time. Unfortunately, using energy from nuclear fusion is far from a reality. Scientists are a long way from developing the necessary technology. One problem is raising temperatures high enough for fusion to take place. Another problem is that matter this hot exists only in the plasma state. There are no known materials that can contain plasma, although a magnet might be able to do it. Thats because plasma consists of ions and responds to magnetism. You can learn more about research on nuclear fusion at the URL below. "
nitrogen bases in dna include,(A) adenine (B) uracil (C) ribose (D) two of the above,A,"As you can see in Figure 5.1, each nucleotide includes a sugar, a phosphate, and a nitrogen base. The sugar in DNA is called deoxyribose. There are four different nitrogen bases in DNA: adenine (A), thymine (T), cytosine (C), and guanine (G). Chemical bonds between the bases hold the two strands of DNA together. Adenine always bonds with thymine, and cytosine always bonds with guanine. These pairs of bases are called complementary base pairs. "
the backbone of a nucleic acid consists of alternating nitrogen bases.,(A) true (B) false,B,"Nucleic acids consist of chains of small molecules called nucleotides. The structure of a nucleotide is shown in Figure 9.23. Each nucleotide contains a phosphate group (PO4 ), a sugar (C5 H8 O4 ) in DNA, and a nitrogen- containing base. (A base is a compound that is not neither acidic nor neutral.) There are four different nitrogenous bases in DNA. They are adenine, thymine, guanine, and cytosine. In RNA, the only difference is that thymine is replaced with a different base, uracil. DNA consists of two long chains of nucleotides. Nitrogen bases on the two chains form hydrogen bonds with each other. Adenine always bonds with thymine, and guanine always bonds with cytosine. These bonds hold the two chains together and give DNA is characteristic double helix, or spiral, shape. You can see the shape of the DNA molecule in Figure 9.24. Sugars and phosphate groups form the ""backbone"" of each chain of DNA. The bonded bases are called base pairs. RNA, in contrast to DNA, consists of just one chain of nucleotides. Determining the structure of DNA was a big scientific breakthrough. You can read the interesting story of its discovery at the URL below. "
functions of rna include,(A) copying the genetic code in DNA (B) carrying the genetic code to the cytoplasm (C) helping to make proteins based on the genetic code (D) all of the above,D,There are three different types of RNA. All three types are needed to make proteins. Messenger RNA (mRNA) copies genetic instructions from DNA in the nucleus. Then it carries the instructions to a ribosome in the cytoplasm. Ribosomal RNA (rRNA) helps form a ribosome. This is where the protein is made. Transfer RNA (tRNA) brings amino acids to the ribosome. The amino acids are then joined together to make the protein. 
dna is found only in the nucleus of cells.,(A) true (B) false,A,"The nucleus is only found in eukaryotic cells. It contains most of the genetic material (the DNA) of the cell. The genetic material of the nucleus is like a set of instructions. These instructions tell the cell how to build molecules needed for the cell to function properly. That is, the DNA tells the cell how to build molecules needed for life. The nucleus is surrounded by the nuclear envelope, a double membrane (two phospholipid bilayers) that controls what goes in and out of the nucleus. The nucleus also has holes embedded in the nuclear envelope. These holes are known as nuclear pores, and they allow things to flow in and out of the nucleus. "
optical instruments include,(A) microscopes (B) telescopes (C) cameras (D) all of the above,D,"Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. "
optical instruments use lenses and mirrors to form images.,(A) true (B) false,A,"Mirrors and lenses are used in optical instruments to reflect and refract light. Optical instruments include micro- scopes, telescopes, cameras, and lasers. "
a compound microscope has,(A) two concave lenses (B) two convex lenses (C) one concave lens and one convex lens (D) none of the above,B,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or more eyepiece lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! For more on light microscopes and the images they create, watch the video at this URL:  (7:29). MEDIA Click image to the left or use the URL below. URL: "
the magnifications of all the lenses of a microscope are added together to yield the overall magnification.,(A) true (B) false,B,"A light microscope is an instrument that uses lenses to make enlarged images of objects that are too small for the unaided eye to see. A common type of light microscope is a compound microscope, like the one in Figure 22.18. A compound microscope has at least two convex lenses: one or more objective lenses and one or more eyepiece lenses. The objective lenses are close to the object being viewed. They form an enlarged image of the object inside the microscope. The eyepiece lenses are close to the viewers eyes. They form an enlarged image of the first image. The magnifications of all the lenses are multiplied together to yield the overall magnification of the microscope. Some light microscopes can magnify objects more than 1000 times! For more on light microscopes and the images they create, watch the video at this URL:  (7:29). MEDIA Click image to the left or use the URL below. URL: "
the part of a camera that focuses light to form an image is the,(A) aperture (B) shutter (C) lens (D) film or sensor,C,"A camera is an optical instrument that forms and records an image of an object. The image may be recorded on film or it may be detected by an electronic sensor that stores the image digitally. Regardless of how the image is recorded, all cameras form images in the same basic way, as shown in the Figure 1.3. Light passes through the lens at the front of the camera and enters the camera through an opening called the aperture. As light passes through the lens, it forms a reduced real image. The image focuses on film (or a sensor) at the back of the camera. The lens may be moved back and forth to bring the image into focus. The shutter controls the amount of light that actually strikes the film (or sensor). It stays open longer in dim light to let more light in. "
the shape of the path in question 2 is,(A) round (B) circular (C) elliptical (D) none of the above,C,The motion of an object can be represented by a distance-time graph like the one in Figure 12.8. A distance-time graph shows how the distance from the starting point changes over time. The graph in Figure 12.8 represents a bike trip. The trip began at 7:30 AM (A) and ended at 12:30 PM (F). The rider traveled from the starting point to a destination and then returned to the starting point again. 
objects that have orbital motion include,(A) moons (B) satellites (C) asteroids (D) all of the above,D,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
it takes earth 24 hours to complete each orbit.,(A) true (B) false,B,"Earth rotates on its axis once every 24 hours. This is the length of an Earth day. Earth orbits the Sun once every 365.24 days. This is the length of an Earth year. Earth has one large moon. This satellite orbits Earth once every 29.5 days. This moon is covered with craters, and also has large plains of lava. The Moon came into being from material that flew into space after Earth and a giant asteroid collided. This moon is not a captured asteroid like other moons in the solar system. "
comets do not have orbital motion.,(A) true (B) false,B,"Comets are small, icy objects that orbit the Sun. Comets have highly elliptical orbits. Their orbits carry them from close to the Sun to the solar systems outer edges. When a comet gets close to the Sun, its outer layers of ice melt and evaporate. The vaporized gas and dust forms an atmosphere around the comet. This atmosphere is called a coma. Radiation and particles streaming from the Sun push some of this gas and dust into a long tail. A comets tail always points away from the Sun, no matter which way the comet is moving. Why do you think that is? Figure Gases in the coma and tail of a comet reflect light from the Sun. Comets are very hard to see except when they have comas and tails. That is why they appear only when they are near the Sun. They disappear again as they move back to the outer solar system. The time between one visit from a comet and the next is called the comets period. The first comet whose period was known was Halleys Comet. Its period is 75 years. Halleys Comet last traveled through the inner solar system in 1986. The comet will appear again in 2061. Who will look up at it? "
an object with orbital motion is constantly accelerating.,(A) true (B) false,A,"Earth and many other bodiesincluding asteroids, comets, and the other planetsmove around the sun in curved paths called orbits. Generally, the orbits are elliptical, or oval, in shape. You can see the shape of Earths orbit in the Figure 1.1. Because of the suns relatively strong gravity, Earth and the other bodies constantly fall toward the sun, but they stay far enough away from the sun because of their forward velocity to fall around the sun instead of into it. As a result, they keep orbiting the sun and never crash to its surface. The motion of Earth and the other bodies around the sun is called orbital motion. Orbital motion occurs whenever an object is moving forward and at the same time is pulled by gravity toward another object. "
which of the following properties characterizes bases?,(A) ability to react with metals (B) sour taste (C) bitter taste (D) two of the above,C,"All bases share certain properties, including a bitter taste. (Warning: Never taste an unknown substance to see whether it is a base!) Bases also feel slippery. Think about how slippery soap feels. Thats because its a base. In addition, bases conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Q: Bases are closely related to compounds called acids. How are their properties similar? How are they different? A: A property that is shared by bases and acids is the ability to conduct electricity when dissolved in water. Some ways bases and acids are different is that acids taste sour whereas bases taste bitter. Also, acids but not bases react with metals. "
examples of acids include,(A) antacid tablets (B) vinegar (C) drain cleaner (D) all of the above,B,"Acids have many important uses, especially in industry. For example, sulfuric acid is used to manufacture a variety of different products, including paper, paint, and detergent. Some other uses of acids are illustrated in Figure 10.7. "
the strength of an acid depends on how many hydrogen ions it produces when it dissolves in water.,(A) true (B) false,A,"The strength of an acid depends on the concentration of hydrogen ions it produces when dissolved in water. A stronger acid produces a greater concentration of ions than a weaker acid. For example, when hydrogen chloride is added to water, all of it breaks down into H+ and Cl ions. Therefore, it is a strong acid. On the other hand, only about 1 percent of acetic acid breaks down into ions, so it is a weak acid. The strength of a base depends on the concentration of hydroxide ions it produces when dissolved in water. For example, sodium hydroxide completely breaks down into ions in water, so it is a strong base. However, only a fraction of ammonia breaks down into ions, so it is a weak base. "
an example of a weak base is sodium hydroxide.,(A) true (B) false,A,"A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ "
acidity is the hydrogen ion concentration of a solution.,(A) true (B) false,A,"The strength of acids is measured on a scale called the pH scale. The pH value of a solution represents its concentration of hydrogen ions. A pH value of 7 indicates a neutral solution, and a pH value less than 7 indicates an acidic solution. The lower the pH value is, the greater is the concentration of hydrogen ions and the stronger the acid. The strongest acids, such as battery acid, have pH values close to zero. "
the reactants of photosynthesis include,(A) oxygen (B) chlorophyll (C) carbon dioxide (D) two of the above,A,"What goes into the plant cell to start photosynthesis? The reactants of photosynthesis are carbon dioxide and water. These are the molecules necessary to begin the process. But one more item is necessary, and that is sunlight. All three components, carbon dioxide, water, and the suns energy are necessary for photosynthesis to occur. These three components must meet in the chloroplast of the leaf cell for photosynthesis to occur. How do these three components get to the cells in the leaf? Chlorophyll is the green pigment in leaves that captures energy from the sun. Chlorophyll molecules are located in the thylakoid membranes inside chloroplasts. The veins in a plant carry water from the roots to the leaves. Carbon dioxide enters the leaf from the air through special openings called stomata ( Figure 1.2). "
the products of photosynthesis include,(A) energy (B) carbon dioxide (C) water (D) oxygen,D,"What is produced by the plant cell during photosynthesis? The products of photosynthesis are glucose and oxygen. This means they are produced at the end of photosynthesis. Glucose, the food of plants, can be used to store energy in the form of large carbohydrate molecules. Glucose is a simple sugar molecule which can be combined with other glucose molecules to form large carbohydrates, such as starch. Oxygen is a waste product of photosynthesis. It is released into the atmosphere through the stomata. As you know, animals need oxygen to live. Without photosynthetic organisms like plants, there would not be enough oxygen in the atmosphere for animals to survive. "
photosynthesis changes light energy to chemical energy.,(A) true (B) false,A,Most of the energy used by living things comes either directly or indirectly from the sun. Sunlight provides the energy for photosynthesis. This is the process in which plants and certain other organisms (see Figure 9.26) synthesize glucose (C6 H12 O6 ). The process uses carbon dioxide and water and also produces oxygen. The overall chemical equation for photosynthesis is: 6CO2 + 6H2 O + Light Energy ! C6 H12 O6 + 6O2 Photosynthesis changes light energy to chemical energy. The chemical energy is stored in the bonds of glucose molecules. Glucose is used for energy by the cells of almost all living things. Plants make their own glucose. Other organisms get glucose by consuming plants (or organisms that consume plants). How do living things get energy from glucose? The answer is cellular respiration. 
photosynthesis takes place in a single chemical reaction.,(A) true (B) false,B,"The overall chemical reaction for photosynthesis is 6 molecules of carbon dioxide (CO2 ) and 6 molecules of water (H2 O), with the addition of solar energy. This produces 1 molecule of glucose (C6 H12 O6 ) and 6 molecules of oxygen Stomata are special pores that allow gasses to enter and exit the leaf. (O2 ). Using chemical symbols, the equation is represented as follows: 6CO2 + 6H2 O  C6 H12 O6 + 6O2 . Though this equation may not seem that complicated, photosynthesis is a series of chemical reactions divided into two stages, the light reactions and the Calvin cycle ( Figure 1.3). "
organisms that undergo photosynthesis include,(A) plants (B) cyanobacteria (C) algae (D) all of the above,D,"The organisms pictured in the Figures 1.1, 1.2, and 1.3 all use sunlight to make glucose in the process of photo- synthesis. In addition to plants, they include bacteria and algae. All of these organisms contain the green pigment chlorophyll, which is needed to capture light energy. A tremendous amount of photosynthesis takes place in the plants of this lush tropi- cal rainforest. "
a position-time graph shows how far an object has traveled at any given time since it started moving.,(A) true (B) false,A,"The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given time since it started moving. Q: In the Figure 1.1, what distance has the object traveled from the starting point by the time 5 seconds have elapsed? A: The object has traveled a distance of 50 meters. "
a position-time graph shows the direction(s) the moving object has traveled relative to the starting position.,(A) true (B) false,A,"The motion of an object can be represented by a position-time graph like Graph 1 in the Figure 1.1. In this type of graph, the y-axis represents position relative to the starting point, and the x-axis represents time. A position-time graph shows how far an object has traveled from its starting position at any given time since it started moving. Q: In the Figure 1.1, what distance has the object traveled from the starting point by the time 5 seconds have elapsed? A: The object has traveled a distance of 50 meters. "
the slope of a position-time graph can be used to find the moving objects,(A) velocity (B) position (C) acceleration (D) none of the above,A,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
"the steeper the line on a position-time graph, the faster the objects motion is changing.",(A) true (B) false,A,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
what is the formula for calculating the average velocity of a moving object?,(A) average velocity = Δd/Δt (B) average velocity = Δt/Δd (C) average velocity = Δd x Δt (D) average velocity = Δd + Δt,A,"Its easy to calculate the average velocity of a moving object from a position-time graph. Average velocity equals the change in position (represented by d) divided by the corresponding change in time (represented by t): velocity = d t For example, in Graph 2 in the Figure 1.2, the average velocity between 0 seconds and 5 seconds is: d t 25 m  0 m = 5 s0 s 25 m = 5s = 5 m/s velocity = "
a person or object may have stored energy because of its,(A) shape (B) position (C) velocity (D) two of the above,D,"Did you ever see a scene like the one in Figure 17.4? In many parts of the world, trees lose their leaves in autumn. The leaves turn color and then fall from the trees to the ground. As the leaves are falling, they have kinetic energy. While they are still attached to the trees they also have energy, but its not because of motion. Instead, they have stored energy, called potential energy. An object has potential energy because of its position or shape. For example leaves on trees have potential energy because they could fall due to the pull of gravity. "
an objects potential energy due to gravity depends on its,(A) weight (B) acceleration (C) height above the ground (D) two of the above,D,"Potential energy due to the position of an object above Earths surface is called gravitational potential energy. Like the diver on the diving board, anything that is raised up above Earths surface has the potential to fall because of gravity. You can see another example of people with gravitational potential energy in the Figure 1.1. Gravitational potential energy depends on an objects weight and its height above the ground. It can be calculated with the equation: Gravitational potential energy (GPE) = weight  height Consider the little girl on the sled, pictured in the Figure 1.1. She weighs 140 Newtons, and the top of the hill is 4 meters higher than the bottom of the hill. As she sits at the top of the hill, the childs gravitational potential energy is: GPE = 140 N  4 m = 560 N  m Notice that the answer is given in Newton  meters (N  m), which is the SI unit for energy. A Newton  meter is the energy needed to move a weight of 1 Newton over a distance of 1 meter. A Newton  meter is also called a joule (J). Q: The gymnast on the balance beam pictured in the Figure 1.1 weighs 360 Newtons. If the balance beam is 1.2 meters above the ground, what is the gymnasts gravitational potential energy? A: Her gravitational potential energy is: GPE = 360 N  1.2 m = 432 N  m, or 432 J "
a stretched rubber band has potential energy.,(A) true (B) false,A,"Potential energy due to an objects shape is called elastic potential energy. This energy results when elastic objects are stretched or compressed. Their elasticity gives them the potential to return to their original shape. For example, the rubber band in Figure 17.6 has been stretched, but it will spring back to its original shape when released. Springs like the handspring in the figure have elastic potential energy when they are compressed. What will happen when the handspring is released? "
food and batteries both contain potential energy.,(A) true (B) false,A,"All of the examples of potential energy described above involve movement or the potential to move. The form of energy that involves movement is called mechanical energy. Other forms of energy also involve potential energy, including chemical energy and nuclear energy. Chemical energy is stored in the bonds between the atoms of compounds. For example, food and batteries both contain chemical energy. Nuclear energy is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. Nuclei of radioactive elements such as uranium are unstable, so they break apart and release the stored energy. "
"compared with a less powerful device, a more powerful device can do",(A) more work in the same time (B) the same work in less time (C) less work in the same time (D) two of the above,D,"Power is a measure of the amount of work that can be done in a given amount of time. Power can be represented by the equation: Power = Work Time In this equation, work is measured in joules (J) and time is measured in seconds (s), so power is expressed in joules per second (J/s). This is the SI unit for power, also known as the watt (W). A watt equals 1 joule of work per second. Youre probably already familiar with watts. Light bulbs and small appliances such as microwave ovens are labeled with the watts of power they provide. For example, the package of light bulbs in the Figure 1.1 is labeled 14 watts. Q: Assume you have two light bulbs of the same type, such as two compact fluorescent light bulbs like the one pictured in the Figure 1.1. If one light bulb is a 25-watt bulb and the other is a 60-watt bulb, which bulb produces brighter light? A: The 60-watt bulb is more powerful, so it produces brighter light. Compared with a less powerful device, a more powerful device can either do more work in the same time or do the same work in less time. For example, compared with a low-power microwave oven, a high-power microwave oven can cook more food in the same time or the same amount of food in less time. "
"if a microwave does 3000 j of work in 3 seconds, its power is",(A) 9000 W (B) 3300 W (C) 2700 W (D) 1000 W,D,"Power can be calculated using the formula above if the amount of work and time are known. For example, assume that a microwave oven does 24,000 joules of work in 30 seconds. Then the power of the microwave is: 24000 J Power = Work Time = 30 s = 800 J/s, or 800 W Q: Another microwave oven does 5,000 joules of work in 5 seconds. What is its power? A: The power of the other microwave oven is: J Power = 5000 5 s = 1000 J/s, or 1000 W Q: Which microwave oven will heat the same amount of food in less time? A: The 1000-watt microwave oven has more power, so it will heat the same amount of food in less time. "
"if you know power and time, you can calculate work with the equation",(A) Work = Power x Time (B) Work = Power/Time (C) Work = Time/Power (D) none of the above,A,"You can also calculate work if you know power and time by rewriting the power equation above as: Work = Power  Time For example, if you use a 1000-watt microwave oven for 20 seconds, how much work does it do? First express 1000 watts in J/s and then substitute this value for power the work equation: Work = 1000 J/s  20 s = 20,000 J "
"to hit the bulls eye of a target, you have to aim an arrow",(A) at the center of the bull’s eye (B) above the bull’s eye (C) below the bull’s eye (D) to one side of the bull’s eye,B,"When the archer releases the bowstring, the arrow will be flung forward toward the top of the target where shes aiming. But another force will also act on the arrow in a different direction. The other force is gravity, and it will pull the arrow down toward Earth. The two forces combined will cause the arrow to move in the curved path shown in the Figure 1.1. This type of motion is called projectile motion. It occurs whenever an object curves down toward the ground because it has both a horizontal force and the downward force of gravity acting on it. Because of projectile motion, to hit the bulls eye of a target with an arrow, you actually have to aim for a spot above the bulls eye. You can see in theFigure 1.2 what happens if you aim at the bulls eye instead of above it. "
examples of objects that have projectile motion include,(A) moons of planets (B) artificial satellites (C) paintballs (D) all of the above,C,"You can probably think of other examples of projectile motion. One is shown in the Figure 1.3. The cannon shoots a ball straight ahead, giving it horizontal motion. At the same time, gravity pulls the ball down toward the ground. Q: How would you show the force of gravity on the cannon ball in the Figure 1.3? A: You would add a line pointing straight down from the cannon to the ground. "
"when an arrow is shot from a bow, forces acting on the arrow include the",(A) elastic force of the bow (B) force of gravity (C) force of friction (D) all of the above,D,"When the archer releases the bowstring, the arrow will be flung forward toward the top of the target where shes aiming. But another force will also act on the arrow in a different direction. The other force is gravity, and it will pull the arrow down toward Earth. The two forces combined will cause the arrow to move in the curved path shown in the Figure 1.1. This type of motion is called projectile motion. It occurs whenever an object curves down toward the ground because it has both a horizontal force and the downward force of gravity acting on it. Because of projectile motion, to hit the bulls eye of a target with an arrow, you actually have to aim for a spot above the bulls eye. You can see in theFigure 1.2 what happens if you aim at the bulls eye instead of above it. "
a cannonball shot from a cannon has projectile motion.,(A) true (B) false,A,"You can probably think of other examples of projectile motion. One is shown in the Figure 1.3. The cannon shoots a ball straight ahead, giving it horizontal motion. At the same time, gravity pulls the ball down toward the ground. Q: How would you show the force of gravity on the cannon ball in the Figure 1.3? A: You would add a line pointing straight down from the cannon to the ground. "
an object with projectile motion constantly changes direction.,(A) true (B) false,A,"Earths gravity also affects the acceleration of objects that start out moving horizontally, or parallel to the ground. Look at Figure 13.21. A cannon shoots a cannon ball straight ahead, giving the ball horizontal motion. At the same time, gravity pulls the ball down toward the ground. Both forces acting together cause the ball to move in a curved path. This is called projectile motion. Projectile motion also applies to other moving objects, such as arrows shot from a bow. To hit the bulls eye of a target with an arrow, you actually have to aim for a spot above the bulls eye. Thats because by the time the arrow reaches the target, it has started to curve downward toward the ground. Figure 13.22 shows what happens if you aim at the bulls eye instead of above it. You can access interactive animations of projectile motion at these URLs: http://phet.colorado.edu/en/simulation/projectile-motion http://jersey.uoregon.edu/vlab/ (Select the applet entitled Cannon.) "
an example of an acid is hcl.,(A) true (B) false,A,"An acid is an ionic compound that produces positive hydrogen ions (H+ ) when dissolved in water. An example is hydrogen chloride (HCl). When it dissolves in water, its hydrogen ions and negative chloride ions (Cl ) separate, forming hydrochloric acid. This can be represented by the equation: HCl H2 O + ! H + Cl "
all acids taste sour.,(A) true (B) false,A,"You already know that a sour taste is one property of acids. (Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity because they consist of charged particles in solution. Acids also react with metals to produce hydrogen gas. For example, when hydrochloric acid (HCl) reacts with the metal magnesium (Mg), it produces magnesium chloride (MgCl2 ) and hydrogen (H2 ). This is a single replacement reaction, represented by the chemical equation: Mg + 2HCl ! H2 + MgCl2 You can see an online demonstration of a similar reaction at this URL: "
"when acids react with metals, they produce",(A) hydrogen gas (B) a salt (C) a base (D) two of the above,D,"You already know that a sour taste is one property of acids. (Warning: Never taste an unknown substance to see whether it is an acid!) Acids have certain other properties as well. For example, acids can conduct electricity when dissolved in water because they consist of charged particles in solution. (Electric current is a flow of charged particles.) Acids can also react with metals, and when they do they produce hydrogen gas. An example of this type of reaction is hydrochloric acid reacting with the metal zinc (Zn). The reaction is pictured in the Figure 1.1. It can be represented by the chemical equation: Zn + 2HCl  H2 + ZnCl2 Q: What sign indicates that a gas is being produced in this reaction? A: The bubbles are hydrogen gas rising through the acid. Q: Besides hydrogen gas, what else is produced in this reaction? A: This reaction also produces zinc chloride ZnCl2 , which is a neutral ionic compound called a salt. "
which statement about ph is true?,(A) A neutral solution has a pH of 0 (B) An acid has a pH greater than 7 (C) An acid has a pH less than 7 (D) A very weak acid has a pH close to 0,C,"The strength of acids and bases is measured on a scale called the pH scale, which is shown in the Figure 1.1. By definition, pH represents the acidity, or hydrogen ion (H+ ) concentration, of a solution. Pure water, which is neutral, has a pH of 7. With a higher the concentration of hydrogen ions, a solution is more acidic and has a lower pH. Acids have a pH less than 7, and the strongest acids have a pH close to zero. Bases have a pH greater than 7, and the strongest bases have a pH close to 14. Its important to realize that the pH scale is based on powers of ten. For example, a solution with a pH of 8 is 10 times more basic than a solution with a pH of 7, and a solution with a pH of 9 is 100 times more basic than a solution with a pH of 7. Q: How much more acidic is a solution with a pH of 4 than a solution with a pH of 7? A: A solution with a pH of 4 is 1000 (10  10  10, or 103 ) times more acidic than a solution with a pH of 7. Q: Which solution on the pH scale in the Figure 1.1 is the weakest acid? Which solution is the strongest base? A: The weakest acid on the scale is milk, which has a pH value between 6.5 and 6.8. The strongest base on the scale is liquid drain cleaner, which has a pH of 14. "
litmus paper is the only indicator of acids.,(A) true (B) false,B,"Certain compounds, called indicators, change color when acids come into contact with them, so indicators can be used to detect acids. An example of an indicator is the compound called litmus. It is placed on small strips of paper that may be red or blue. If you place a few drops of acid on a strip of blue litmus paper, the paper will turn red. You can see this in the Figure 1.2. Litmus isnt the only indicator for detecting acids. Red cabbage juice also works well, as you can see in this entertaining video. Click image to the left or use the URL below. URL:  Drawing of blue litmus paper turning red in acid. "
an example of a base is sodium hydroxide (naoh).,(A) true (B) false,A,"A base is an ionic compound that produces negative hydroxide ions (OH ) when dissolved in water. For example, when the compound sodium hydroxide (NaOH) dissolves in water, it produces hydroxide ions and positive sodium ions (Na+ ). This can be represented by the equation: NaOH H2 O ! OH + Na+ "
bases feel slippery to the touch.,(A) true (B) false,A,"All bases share certain properties, including a bitter taste. (Never taste an unknown substance to see whether it is a base!) Did you ever taste unsweetened cocoa powder? It tastes bitter because it is a base. Bases also feel slippery. Think about how slippery soap feels. Soap is also a base. Like acids, bases conduct electricity because they consist of charged particles in solution. "
bases can react with metals.,(A) true (B) false,B,Acids are ionic compounds that produce positively charged hydrogen ions (H+ ) when dissolved in water. Acids taste sour and react with metals. Bases are ionic compounds that produce negatively charged hydroxide ions (OH ) when dissolved in water. Bases taste bitter and do not react with metals. Examples of acids are vinegar and battery acid. The acid in vinegar is weak enough to safely eat on a salad. The acid in a car battery is strong enough to eat through skin. Examples of bases include those in antacid tablets and drain cleaner. Bases in antacid tablets are weak enough to take for an upset stomach. Bases in drain cleaner are strong enough to cause serious burns. Q: What do you think causes these differences in the strength of acids and bases? A: The strength of an acid or a base depends on how much of it breaks down into ions when it dissolves in water. 
bases turn red litmus paper blue.,(A) true (B) false,A,"Bases change the color of certain compounds, and this property can be used to detect them. A common indicator of bases is red litmus paper. Bases turn red litmus paper blue. You can see an example in Figure 10.8. Red cabbage juice can detect bases as well as acids, as youll see by reviewing this video:  MEDIA Click image to the left or use the URL below. URL: "
bases are used to make,(A) soaps (B) cleaning products (C) concrete (D) all of the above,D,"Bases are used for a variety of purposes. For example, soaps contain bases such as potassium hydroxide. Other uses of bases are pictured in Figure 10.9. "
the strongest bases have ph values close to,(A) 0 (B) 5 (C) 7 (D) 14,D,"The strength of bases is measured on a scale called the pH scale, which ranges from 0 to 14. On this scale, a pH value of 7 indicates a neutral solution, and a pH value greater than 7 indicates a basic solution. The higher the pH value is, the stronger the base. The strongest bases, such as drain cleaner, have a pH value close to 14. "
properties of electromagnetic waves include,(A) speed (B) frequency (C) wavelength (D) all of the above,D,Wavelength and frequency are defined in the same way for electromagnetic waves as they are for mechanical waves. Both properties are illustrated in Figure 21.5. Wavelength is the distance between corresponding points of adjacent waves. Wavelengths of electromagnetic waves range from many kilometers to a tiny fraction of a millimeter. Frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electro- magnetic waves range from thousands to trillions of waves per second. Higher frequency waves have greater energy. 
all electromagnetic waves travel at the same speed through space.,(A) true (B) false,A,"All electromagnetic waves travel at the same speed through empty space. That speed, called the speed of light, is about 300 million meters per second (3.0 x 108 m/s). Nothing else in the universe is known to travel this fast. The sun is about 150 million kilometers (93 million miles) from Earth, but it takes electromagnetic radiation only 8 minutes to reach Earth from the sun. If you could move that fast, you would be able to travel around Earth 7.5 times in just 1 second! "
higher-frequency electromagnetic waves have less energy.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed across space, they may differ in their wavelengths, frequencies, and energy levels. Wavelength is the distance between corresponding points of adjacent waves (see the Figure 1.1). Wavelengths of electromagnetic waves range from longer than a soccer field to shorter than the diameter of an atom. Wave frequency is the number of waves that pass a fixed point in a given amount of time. Frequencies of electromagnetic waves range from thousands of waves per second to trillions of waves per second. The energy of electromagnetic waves depends on their frequency. Low-frequency waves have little energy and are normally harmless. High-frequency waves have a lot of energy and are potentially very harmful. Q: Which electromagnetic waves do you think have higher frequencies: visible light or X rays? A: X rays are harmful but visible light is harmless, so you can infer that X rays have higher frequencies than visible light. "
some electromagnetic waves have wavelengths shorter than the diameter of an atom.,(A) true (B) false,A,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
all electromagnetic waves have frequencies of less than 1000 waves per second.,(A) true (B) false,B,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
the highest-frequency electromagnetic waves,(A) include visible light (B) are harmful (C) have the longest wavelengths (D) two of the above,B,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
which equation shows the relationship of wave speed to wavelength and wave frequency?,(A) Speed = Wavelength x Frequency (B) Speed = Wavelength/Frequency (C) Speed = Frequency/Wavelength (D) none of the above,A,"The equation for wave speed (above) can be rewritten as: Frequency = Speed Wavelength or Wavelength = Speed Frequency Therefore, if you know the speed of a wave and either the wavelength or wave frequency, you can calculate the missing value. For example, suppose that a wave is traveling at a speed of 2 meters per second and has a wavelength of 1 meter. Then the frequency of the wave is: Frequency = 2m/s 1m = 2 waves/s, or 2 Hz Q: A wave is traveling at a speed of 2 m/s and has a frequency of 2 Hz. What is its wavelength? A: Substitute these values into the equation for wavelength: Wavelength = 2m/s 2waves/s =1m "
proteins are the most numerous and diverse biochemical compounds.,(A) true (B) false,A,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
elements that make up proteins include,(A) nitrogen (B) phosphorus (C) hemoglobin (D) two of the above,A,"Proteins are biochemical compounds that contain oxygen, nitrogen, and sulfur in addition to carbon and hydrogen. Protein molecules consist of one or more chains of small molecules called amino acids. "
there are hundreds of different amino acids.,(A) true (B) false,B,"Amino acids are the ""building blocks"" of proteins. There are 20 different common amino acids. The structural formula of the simplest amino acid, called glycine, is shown in Figure 9.19. Other amino acids have a similar structure. The sequence of amino acids and the number of amino acid chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. You can learn more about the structure of proteins at the URL below. MEDIA Click image to the left or use the URL below. URL: "
what determines the shape of a protein?,(A) amino acid sequence of each chain (B) folding of each amino acid chain (C) number of amino acid chains (D) all of the above,D,"Amino acids are the building blocks of proteins. There are 20 different amino acids. The structural formula of the simplest amino acid, called glycine, is shown in the Figure 1.1. Other amino acids have slightly different structures. A protein molecule is made from one or more long chains of amino acids, each linked to its neighbors by covalent bonds. If a protein has more than one chain, the chains are held together by weaker bonds, such as hydrogen bonds. The sequence of amino acids in chains and the number of chains in a protein determine the proteins shape. The shape of a protein, in turn, determines its function. Shapes may be very complex. Click image to the left or use the URL below. URL:  Q: What do you think the ribbons in the colorful hemoglobin molecule pictured in the opening image represent? A: The ribbons represent chains of amino acids. "
examples of proteins by function include,(A) hormones (B) antibodies (C) enzymes (D) all of the above,D,"Proteins are the most numerous and diverse biochemical compounds, and they have many different functions. Some of their functions include: making up tissues as components of muscle. speeding up biochemical reactions as enzymes. regulating life processes as hormones. helping to defend against infections as antibodies. carrying materials around the body as transport proteins (see the example of hemoglobin in the Figure 1.2). "
some proteins carry other materials in the blood.,(A) true (B) false,A,"Hemoglobin is a compound in the class of compounds called proteins. Proteins are one of four classes of biochemi- cal compounds, which are compounds in living things. (The other three classes are carbohydrates, lipids, and nucleic acids.) Proteins contain carbon, hydrogen, oxygen, nitrogen, and sulfur. Protein molecules consist of one or more chains of small molecules called amino acids. "
protons are one of three main types of particles that make up atoms.,(A) true (B) false,A,"A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67  1027 kilograms. Together with neutrons, they make up virtually all of the mass of an atom. Click image to the left or use the URL below. URL:  Q: How do you think the sun is related to protons? A: The suns tremendous energy is the result of proton interactions. In the sun, as well as in other stars, protons from hydrogen atoms combine, or fuse, to form nuclei of helium atoms. This fusion reaction releases a huge amount of energy and takes place in nature only at the extremely high temperatures of stars such as the sun. "
protons are found only in the atomic nucleus.,(A) true (B) false,A,"A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67  1027 kilograms. Together with neutrons, they make up virtually all of the mass of an atom. Click image to the left or use the URL below. URL:  Q: How do you think the sun is related to protons? A: The suns tremendous energy is the result of proton interactions. In the sun, as well as in other stars, protons from hydrogen atoms combine, or fuse, to form nuclei of helium atoms. This fusion reaction releases a huge amount of energy and takes place in nature only at the extremely high temperatures of stars such as the sun. "
which of the following correctly describes a proton?,(A) It has an electrical charge of +2 (B) It has a mass of 1 mg (C) It has a diameter of 17 x 10-27 km (D) none of the above,D,"A proton is a particle in the nucleus of an atom that has a positive electric charge. All protons are identical. It is the number of protons that gives atoms of different elements their unique properties. Atoms of each type of element have a characteristic number of protons. For example, each atom of carbon has six protons, as you can see in Figure "
"in the sun, protons of hydrogen atoms",(A) fission to form energy (B) fuse to form helium nuclei (C) melt to form light (D) none of the above,B,"A proton is one of three main particles that make up the atom. The other two particles are the neutron and electron. Protons are found in the nucleus of the atom. This is a tiny, dense region at the center of the atom. Protons have a positive electrical charge of one (+1) and a mass of 1 atomic mass unit (amu), which is about 1.67  1027 kilograms. Together with neutrons, they make up virtually all of the mass of an atom. Click image to the left or use the URL below. URL:  Q: How do you think the sun is related to protons? A: The suns tremendous energy is the result of proton interactions. In the sun, as well as in other stars, protons from hydrogen atoms combine, or fuse, to form nuclei of helium atoms. This fusion reaction releases a huge amount of energy and takes place in nature only at the extremely high temperatures of stars such as the sun. "
the atoms of different elements have,(A) different numbers of protons (B) different types of protons (C) the same number of protons (D) two of the above,A,"All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their numbers of neutrons are called isotopes. Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same physical and chemical properties. Thats because they have the same numbers of protons and electrons. Click image to the left or use the URL below. URL: "
what are protons made of?,(A) gluons (B) neutrons (C) quarks (D) two of the above,D,"Protons are made of fundamental particles called quarks and gluons. As you can see in the Figure 1.1, a proton contains three quarks (colored circles) and three streams of gluons (wavy white lines). Two of the quarks are called up quarks (u), and the third quark is called a down quark (d). The gluons carry the strong nuclear force between quarks, binding them together. This force is needed to overcome the electric force of repulsion between positive protons. Although protons were discovered almost 100 years ago, the quarks and gluons inside them were discovered much more recently. Scientists are still learning more about these fundamental particles. "
protons have less mass than electrons.,(A) true (B) false,B,"Electrons are extremely small. The mass of an electron is only about 1/2000 the mass of a proton or neutron, so electrons contribute virtually nothing to the total mass of an atom. Electrons have an electric charge of -1, which is equal but opposite to the charge of proton, which is +1. All atoms have the same number of electrons as protons, so the positive and negative charges cancel out, making atoms electrically neutral. "
a flagpole pulley is a,(A) fixed pulley (B) moveable pulley (C) compound pulley (D) none of the above,A,"Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure 1.3 how each of these machines works. In both cases, the direction of the force applied by the user is reversed by the machine. Q: If the pulley only changes the direction of the force, how does it make the work of raising the flag easier? A: The pulley makes it easier to lift the flag because it allows a person to pull down on the rope and add his or her own weight to the effort, rather than simply lifting the load. "
the ideal mechanical advantage of a pulley is equal to the number of rope segments pulling up on the load.,(A) true (B) false,A,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
a moveable pulley changes the direction of the input force.,(A) true (B) false,B,"Some machines change the direction of the force applied by the user. They may or may not also change the strength of the force or the distance over which the force is applied. Two examples of machines that work this way are the claw ends of hammers and flagpole pulleys. You can see in the Figure 1.3 how each of these machines works. In both cases, the direction of the force applied by the user is reversed by the machine. Q: If the pulley only changes the direction of the force, how does it make the work of raising the flag easier? A: The pulley makes it easier to lift the flag because it allows a person to pull down on the rope and add his or her own weight to the effort, rather than simply lifting the load. "
a zip-line pulley is a moveable pulley.,(A) true (B) false,A,"Some pulleys are attached to a beam or other secure surface and remain fixed in place. They are called fixed pulleys. Other pulleys are attached to the object being moved and are moveable themselves. They are called moveable pulleys. Sometimes, fixed and moveable pulleys are used together. They make up a compound pulley. The three types of pulleys are compared in the Table 1.1. Q: Which type of pulley is the old pulley in the opening image? A: The old pulley is a single fixed pulley. It is securely attached to the beam above it. Type of Pulley How It Works Example Single fixed pul- ley Flagpole pulley No. of Rope Segments Pulling Up 1 Ideal Mechani- cal Advantage 1 Change Direction Force? yes Single moveable pulley Zip-line pulley 2 2 no Compound pulley (fixed & moveable pulleys) Crane pulley 2 2 varies in of "
which type(s) of pulley can have a mechanical advantage greater than 2?,(A) fixed pulley (B) moveable pulley (C) compound pulley (D) two of the above,C,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
all pulleys increase the force applied to the pulley.,(A) true (B) false,B,"The mechanical advantage of a simple machine such as a pulley is the factor by which the machine changes the force applied to it. The ideal mechanical advantage of a machine is its mechanical advantage in the absence of friction. All machines must overcome friction, so the ideal mechanical advantage is always somewhat greater than the actual mechanical advantage of the machine as it is used in the real world. In a pulley, the ideal mechanical advantage is equal to the number of rope segments pulling up on the object. The more rope segments that are helping to do the lifting work, the less force that is needed for the job. Look at the table of types of pulleys. It gives the ideal mechanical advantage of each type. In the single fixed pulley, only one rope segment pulls up on the load, so the ideal mechanical advantage is 1. In other words, this type of pulley doesnt increase the force that is applied to it. However, it does change the direction of the force. This allows you to use your weight to pull on one end of the rope and more easily raise the load attached to the other end. In the single moveable pulley, two rope segments pull up on the load, so the ideal mechanical advantage is 2. This type of pulley doesnt change the direction of the force applied to it, but it increases the force by a factor of 2. In a compound pulley, two or more rope segments pull up on the load, so the ideal mechanical advantage is 2 or greater than 2. This type of pulley may or may not change the direction of the force applied to itit depends on the number and arrangement of pulleysbut the increase in force may be great. Q: If a compound pulley has four rope segments pulling up on the load, by what factor does it multiply the force applied to the pulley? A: With four rope segments, the ideal mechanical advantage is 4. This means that the compound pulley multiplies the force applied to it by a factor of 4. For example if 400 Newtons of force were applied to the pulley, the pulley would apply 1600 Newtons of force to the load. "
electromagnetic waves vary in their wavelengths and frequencies.,(A) true (B) false,A,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
radio waves have the highest frequencies of all electromagnetic waves.,(A) true (B) false,B,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
radio waves have the least energy of all electromagnetic waves.,(A) true (B) false,A,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
radio waves vary in frequency from,(A) 105 to 1012 Hz (B) 1050 to 10 (C) 120 Hz (D) c 10 (E) 500 to 101 (F) 200 Hz (G) d none of the above,A,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
am radio waves,(A) have longer wavelengths than FM radio waves (B) are encoded with signals by changing their amplitude (C) reflect off the ionosphere (D) all of the above,D,"Radio waves are the broad range of electromagnetic waves with the longest wavelengths and lowest frequencies. In Figure 21.7, you can see that the wavelength of radio waves may be longer than a soccer field. With their low frequencies, radio waves have the least energy of electromagnetic waves, but they still are extremely useful. They are used for radio and television broadcasts, microwave ovens, cell phone transmissions, and radar. You can learn more about radio waves, including how they were discovered, at this URL:  MEDIA Click image to the left or use the URL below. URL: "
in tv broadcasts,(A) radio waves carry both sound and picture signals (B) sounds are encoded withy amplitude modulation (C) pictures are encoded with frequency modulation (D) all of the above,A,"Television broadcasts also use radio waves (see Figure 1.2). For TV broadcasts, sounds are encoded with frequency modulation, and pictures are encoded with amplitude modulation. The encoded waves are broadcast from a TV tower. When the waves are received by television sets, they are decoded and changed back to sounds and pictures. "
radioactive decay is a chemical reaction.,(A) true (B) false,B,"Radioactive decay is the process in which the nuclei of radioactive atoms emit charged particles and energy, which are called by the general term radiation. Radioactive atoms have unstable nuclei, and when the nuclei emit radiation, they become more stable. Radioactive decay is a nuclearrather than chemicalreaction because it involves only the nuclei of atoms. In a nuclear reaction, one element may change into another. Click image to the left or use the URL below. URL: "
radioactive decay may change one element into another.,(A) true (B) false,A,"Radioactive decay is the breakdown of unstable elements into stable elements. To understand this process, recall that the atoms of all elements contain the particles protons, neutrons, and electrons. "
energy is emitted by a nucleus when it undergoes,(A) alpha decay (B) beta decay (C) gamma decay (D) any of the above,D,Nuclear energy is produced by splitting the nucleus of an atom. This releases a huge amount of energy. 
the type of radioactive decay that occurs when a nucleus emits an electron is,(A) alpha decay (B) beta decay (C) gamma decay (D) none of the above,B,"There are several types of radioactive decay, including alpha, beta, and gamma decay. In all three types, nuclei emit radiation, but the nature of the radiation differs. The Table 1.1 shows the radiation emitted in each type of decay. Type Alpha decay Beta decay Gamma decay Radiation Emitted alpha particle (2 protons and 2 neutrons) + energy beta particle (1 electron or 1 positron) + energy energy (gamma ray) "
the type of radioactive decay that occurs when a nucleus emits two protons and two neutrons is,(A) alpha decay (B) beta decay (C) gamma decay (D) none of the above,A,"There are several types of radioactive decay, including alpha, beta, and gamma decay. In all three types, nuclei emit radiation, but the nature of the radiation differs. The Table 1.1 shows the radiation emitted in each type of decay. Type Alpha decay Beta decay Gamma decay Radiation Emitted alpha particle (2 protons and 2 neutrons) + energy beta particle (1 electron or 1 positron) + energy energy (gamma ray) "
certain chemical processes can change one element into another.,(A) true (B) false,B,"A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. Click image to the left or use the URL below. URL: "
atoms of each element have a unique number of,(A) protons (B) neutrons (C) isotopes (D) two of the above,A,"All atoms of the same element have the same number of protons, but some may have different numbers of neutrons. For example, all carbon atoms have six protons, and most have six neutrons as well. But some carbon atoms have seven or eight neutrons instead of the usual six. Atoms of the same element that differ in their numbers of neutrons are called isotopes. Many isotopes occur naturally. Usually one or two isotopes of an element are the most stable and common. Different isotopes of an element generally have the same physical and chemical properties. Thats because they have the same numbers of protons and electrons. Click image to the left or use the URL below. URL: "
all nuclei emit radiation.,(A) true (B) false,B,"Radioactivity is the ability of an atom to emit, or give off, charged particles and energy from its nucleus. The charged particles and energy are called by the general term radiation. Only unstable nuclei emit radiation. They are unstable because they have too much energy, too many protons, or an unstable ratio of protons to neutrons. For example, all elements with more than 83 protonssuch as uranium, radium, and poloniumhave unstable nuclei. They are called radioactive elements. The nuclei of these elements must lose protons to become more stable. When they do, they become different elements. "
nuclei may be unstable if they have,(A) too much energy (B) too many protons (C) an unstable ratio of protons to neutrons (D) any of the above,D,"All the atoms of a given element have the same number of protons in their nucleus, but they may have different numbers of neutrons. Atoms of the same element with different numbers of neutrons are called isotopes. Many elements have one or more isotopes that are radioactive. These isotopes are called radioisotopes. Their nuclei are unstable, so they break down, or decay, and emit radiation. Q: What makes the nucleus of a radioisotope unstable? A: The nucleus may be unstable because it has too many protons or an unstable ratio of protons to neutrons. For a nucleus with a small number of protons to be stable, the ratio of protons to neutrons should be 1:1. For a nucleus with a large number of protons to be stable, the ratio should be about 1:1.5. "
all elements with more than 75 protons are unstable.,(A) true (B) false,B,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
which of the following elements are radioactive?,(A) uranium (B) radium (C) polonium (D) all of the above,D,"Radioactive decay is the breakdown of unstable elements into stable elements. To understand this process, recall that the atoms of all elements contain the particles protons, neutrons, and electrons. "
only radioactive elements have isotopes that are radioactive.,(A) true (B) false,B,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
radioactive isotopes are unstable because they have too many electrons.,(A) true (B) false,B,"Atoms need a certain ratio of neutrons to protons to have a stable nucleus. Having too many or too few neutrons relative to protons results in an unstable, or radioactive, nucleus that will sooner or later break down to a more stable form. This process is called radioactive decay. Many isotopes have radioactive nuclei, and these isotopes are referred to as radioisotopes. When they decay, they release particles that may be harmful. This is why radioactive isotopes are dangerous and why working with them requires special suits for protection. The isotope of carbon known as carbon-14 is an example of a radioisotope. In contrast, the carbon isotopes called carbon-12 and carbon-13 are stable. "
the nucleus that is most likely to be unstable is the nucleus that has,(A) 2 protons and 2 neutrons (B) 4 protons and 4 neutrons (C) 6 protons and 8 neutrons (D) 60 protons and 90 neutrons,C,"In elements with more than 83 protons, all of the isotopes are radioactive. In the Figure 1.1, these are the elements with a yellow background. The force of repulsion among all those protons makes the nuclei unstable. Elements with more than 92 protons have such unstable nuclei that they dont even exist in nature. They have only been created in labs. "
the radioisotope of carbon is called,(A) carbon-6 (B) carbon-8 (C) carbon-13 (D) carbon-14,D,"For most other elements, isotopes are named for their mass number. For example, carbon atoms with the usual 6 neutrons have a mass number of 12 (6 protons + 6 neutrons = 12), so they are called carbon-12. Carbon atoms with 7 neutrons have an atomic mass of 13 (6 protons + 7 neutrons = 13). These atoms are the isotope called carbon-13. Some carbon atoms have 8 neutrons. What is the name of this isotope of carbon? You can learn more about this isotope at the URL below. It is used by scientists to estimate the ages of rocks and fossils. "
chemical changes occur because of chemical reactions.,(A) true (B) false,A,"A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. Click image to the left or use the URL below. URL: "
an example of a chemical change is a candle burning.,(A) true (B) false,A,"A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. Click image to the left or use the URL below. URL: "
any substance that starts a chemical reaction is called a,(A) reactor (B) regent (C) reactant (D) none of the above,C,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
any substance that results from a chemical reaction is called a,(A) producer (B) product (C) productor (D) none of the above,B,"A chemical reaction is a process in which some substances change into different substances. Substances that start a chemical reaction are called reactants. Substances that are produced in the reaction are called products. Reactants and products can be elements or compounds. A chemical reaction can be represented by this general equation: Reactants ! Products The arrow (!) shows the direction in which the reaction occurs. The reaction may occur quickly or slowly. For example, foam shoots out of a fire extinguisher as soon as the lever is pressed. But it might take years for metal to rust. "
products of a combustion reaction include,(A) fuel (B) oxygen (C) water (D) two of the above,C,"A combustion reaction occurs when a substance reacts quickly with oxygen (O2 ). For example, in the Figure usually referred to as fuel. The products of a complete combustion reaction include carbon dioxide (CO2 ) and water vapor (H2 O). The reaction typically gives off heat and light as well. The general equation for a complete combustion reaction is: Fuel + O2  CO2 + H2 O The burning of charcoal is a combustion reaction. "
all changes in matter are the result of chemical reactions.,(A) true (B) false,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
signs that a chemical reaction has occurred include a change in,(A) temperature (B) color (C) state (D) two of the above,D,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
which of the following is a sign of a chemical reaction?,(A) A liquid changes to a solid (B) A liquid changes to a gas (C) A solid changes to a gas (D) A gas is released from a liquid,D,A change in color is just one of several potential signs that a chemical reaction has occurred. Other potential signs include: Change in temperature-Heat is released or absorbed during the reaction. Production of a gas-Gas bubbles are released during the reaction. Production of a solid-A solid settles out of a liquid solution. The solid is called a precipitate. Click image to the left or use the URL below. URL: 
the solid lumps in cottage cheese are an example of a precipitate.,(A) true (B) false,A,"When water evaporates, it leaves behind a solid precipitate of minerals, as shown in Figure 1.2. When the water in glass A evaporates, the dissolved mineral particles are left behind. Water can only hold a certain amount of dissolved minerals and salts. When the amount is too great to stay dissolved in the water, the particles come together to form mineral solids, which sink. Halite easily precipitates out of water, as does calcite. Some lakes, such as Mono Lake in California (Figure 1.3) or The Great Salt Lake in Utah, contain many mineral precipitates. Tufa towers form when calcium-rich spring water at the bottom of Mono Lake bubbles up into the alkaline lake. The tufa towers appear when lake level drops. "
the release of gas bubbles is a sign of a chemical reaction.,(A) true (B) false,A,"Look carefully at the Figures 1.1, 1.2, and 1.3. All of the photos demonstrate chemical reactions. For each photo, identify a sign that one or more chemical reactions have taken place. A burning campfire can warm you up on a cold day. Dissolving an antacid tablet in water produces a fizzy drink. Adding acid to milk produces solid curds of cottage cheese. Q: Did you ever make a volcano by pouring vinegar over a mountain of baking soda? If you did, you probably saw the mixture bubble up and foam over. Did a chemical reaction occur? How do you know? A: Yes, a chemical reaction occurred. You know because the bubbles are evidence that a gas has been produced and production of a gas is a sign of a chemical reaction. "
which of the following does not involve chemical reactions?,(A) Leaves change color in the fall (B) A pond freezes over in the winter (C) A fire burns a pile of fallen leaves (D) Fallen leaves decay in a compost pile,B,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
less reactive elements replace more reactive elements in compounds.,(A) true (B) false,B,"A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal are held together by ionic bonds. Generally, a more reactive element replaces an element that is less reactive, and the less reactive element is set free from the compound. There are two types of replacement reactions: single and double. Both types are described below. Q: Can you predict how single and double replacement reactions differ? A: One way they differ is that a single replacement reaction involves one reactant compound, whereas a double replacement reaction involves two reactant compounds. Keep reading to learn more about these two types of reactions. "
replacement reactions always involve ionic compounds.,(A) true (B) false,A,Replacement reactions involve ions. They occur when ions switch places in compounds. There are two types of replacement reactions: single and double. Both types are described below. 
a single replacement reaction always involves two reactant compounds.,(A) true (B) false,B,Replacement reactions involve ions. They occur when ions switch places in compounds. There are two types of replacement reactions: single and double. Both types are described below. 
which of the following is a single replacement reaction?,(A) FeS + 2HCl → H2S + FeCl2 (B) Fe + CuSO4 → FeSO4 + Cu (C) AgNO3 + NaCl ---> AgCl + NaNO3 (D) none of the above,B,"A single replacement reaction occurs when one ion takes the place of another in a single compound. This type of reaction has the general equation: A + BC ! B + AC Do you see how A has replaced B in the compound? The compound BC has become the compound AC. An example of a single replacement reaction occurs when potassium (K) reacts with water (H2 O). A colorless solid called potassium hydroxide (KOH) forms, and hydrogen gas (H2 ) is released. The equation for the reaction is: 2K + 2H2 O ! 2KOH + H2 Potassium is a highly reactive group 1 alkali metal, so its reaction with water is explosive. You can actually watch this reaction occurring at: http://commons.wikimedia.org/wiki/File:Potassium_water_20.theora.ogv . "
the general equation for a double replacement reaction is,(A) AB + CD → BC + DA (B) AB + C + D → AD + CB (C) AB + C → AC + B (D) none of the above,D,A double replacement reaction occurs when two compounds exchange ions. This produces two new compounds. A double replacement reaction can be represented by the general equation: AB +CD ! AD +CB Do you see how B and D have changed places? Both reactant compounds have changed. An example of a double replacement reaction is sodium chloride (NaCl) reacting with silver fluoride (AgF). This reaction is represented by the equation: NaCl + AgF ! NaF + AgCl Cl and F have changed places. Can you name the products of this reaction? 
a compound in a replacement reaction always consists of,(A) a positive ion and a negative ion (B) a metal ion and a nonmetal ion (C) two negative metal ions (D) two of the above,D,"A replacement reaction occurs when elements switch places in compounds. This type of reaction involves ions (electrically charged versions of atoms) and ionic compounds. These are compounds in which positive ions of a metal and negative ions of a nonmetal are held together by ionic bonds. Generally, a more reactive element replaces an element that is less reactive, and the less reactive element is set free from the compound. There are two types of replacement reactions: single and double. Both types are described below. Q: Can you predict how single and double replacement reactions differ? A: One way they differ is that a single replacement reaction involves one reactant compound, whereas a double replacement reaction involves two reactant compounds. Keep reading to learn more about these two types of reactions. "
"in rutherfords experiments, most of the alpha particles",(A) were deflected by the gold foil (B) passed straight through the gold foil (C) bounced straight back from the gold foil (D) none of the above,B,"In 1899, Rutherford discovered that some elements give off positively charged particles. He named them alpha particles (a). In 1911, he used alpha particles to study atoms. He aimed a beam of alpha particles at a very thin sheet of gold foil. Outside the foil, he placed a screen of material that glowed when alpha particles struck it. If Thomsons plum pudding model were correct, the alpha particles should be deflected a little as they passed through the foil. Why? The positive ""pudding"" part of gold atoms would slightly repel the positive alpha particles. This would cause the alpha particles to change course. But Rutherford got a surprise. Most of the alpha particles passed straight through the foil as though they were moving through empty space. Even more surprising, a few of the alpha particles bounced back from the foil as though they had struck a wall. This is called back scattering. It happened only in very small areas at the centers of the gold atoms. "
"from his results, rutherford concluded that the positive charge of an atom is",(A) less than the negative charge of the atom (B) spread evenly throughout the atom (C) concentrated in a tiny area at the center of the atom (D) two of the above,C,"Based on his results, Rutherford concluded that all the positive charge of an atom is concentrated in a small central area. He called this area the nucleus. Rutherford later discovered that the nucleus contains positively charged particles. He named the positive particles protons. Rutherford also predicted the existence of neutrons in the nucleus. However, he failed to find them. One of his students, a physicist named James Chadwick, went on to discover neutrons in 1932. You learn how at this URL:  . "
"based on his research, rutherford thought that most of an atom consists of empty space.",(A) true (B) false,A,"Rutherford made the same inferences. He concluded that all of the positive charge and virtually all of the mass of an atom are concentrated in one tiny area and the rest of the atom is mostly empty space. Rutherford called the area of concentrated positive charge the nucleus. He predictedand soon discoveredthat the nucleus contains positively charged particles, which he named protons. Rutherford also predicted the existence of neutral nuclear particles called neutrons, but he failed to find them. However, his student James Chadwick discovered them several years later. "
rutherford predicted the existence of neutrons but failed to find them.,(A) true (B) false,A,"Based on his results, Rutherford concluded that all the positive charge of an atom is concentrated in a small central area. He called this area the nucleus. Rutherford later discovered that the nucleus contains positively charged particles. He named the positive particles protons. Rutherford also predicted the existence of neutrons in the nucleus. However, he failed to find them. One of his students, a physicist named James Chadwick, went on to discover neutrons in 1932. You learn how at this URL:  . "
the melting points of saturated hydrocarbons are determined mainly by their number of,(A) double bonds (B) hydrogen atoms (C) carbon atoms (D) none of the above,C,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
which saturated hydrocarbon has the chemical formula c2h6?,(A) methane (B) ethane (C) propane (D) butane,B,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
which saturated hydrocarbon has eight carbon atoms?,(A) pentane (B) hexane (C) heptane (D) octane,D,"Saturated hydrocarbons are hydrocarbons that contain only single bonds between carbon atoms. They are the simplest class of hydrocarbons. They are called saturated because each carbon atom is bonded to as many hydrogen atoms as possible. In other words, the carbon atoms are saturated with hydrogen. You can see an example of a saturated hydrocarbon in the Figure 1.1. In this compound, named ethane, each carbon atom is bonded to three hydrogen atoms. In the structural formula, each dash (-) represents a single covalent bond, in which two atoms share one pair of valence electrons. Q: What is the chemical formula for ethane? A: The chemical formula is C2 H6 . "
methane has a higher boiling point than ethane.,(A) true (B) false,B,Natural gas is mostly methane. 
some alkanes are solids are room temperature.,(A) true (B) false,A,"Saturated hydrocarbons are given the general name of alkanes. The name of specific alkanes always ends in -ane. The first part of the name indicates how many carbon atoms each molecule of the alkane has. The smallest alkane is methane. It has just one carbon atom. The next largest is ethane with two carbon atoms. The chemical formulas and properties of methane, ethane, and other small alkanes are listed in the Table 1.1. The boiling and melting points of alkanes are determined mainly by the number of carbon atoms they have. Alkanes with more carbon atoms generally boil and melt at higher temperatures. Alkane Methane Ethane Propane Butane Pentane Hexane Heptane Octane Chemical Formula CH4 C2 H6 C3 H8 C4 H10 C5 H12 C6 H14 C7 H16 C8 H18 Boiling Point( C) -162 -89 -42 0 36 69 98 126 Melting Point( C) -183 -172 -188 -138 -130 -95 -91 -57 State (at 20  C) gas gas gas gas liquid liquid liquid liquid Q: The Table 1.1 shows only alkanes that have relatively few carbon atoms. Some alkanes have many more carbon atoms. What properties might larger alkanes have? A: Alkanes with more carbon atoms have higher boiling and melting points, so some of them are solids at room temperature. "
types of graphs include,(A) bar graphs (B) line graphs (C) circle graphs (D) all of the above,D,"Graphs are very useful tools in science. They can help you visualize a set of data. With a graph, you can actually see what all the numbers in a data table mean. Three commonly used types of graphs are bar graphs, circle graphs, and line graphs. Each type of graph is suitable for showing a different type of data. "
different types of graph are best suited for representing different types of data.,(A) true (B) false,A,"Graphs are very useful tools in science. They can help you visualize a set of data. With a graph, you can actually see what all the numbers in a data table mean. Three commonly used types of graphs are bar graphs, circle graphs, and line graphs. Each type of graph is suitable for showing a different type of data. "
"to be useful, a scientific model must",(A) closely represent the real thing in important ways (B) be simpler than the real thing (C) be easier to understand than the real thing (D) all of the above,D,"Scientific models are useful tools in science. Earths climate is extremely complex, with many factors that are dependent on one another. Such a system is impossible for scientists to work with as a whole. To deal with such complexity, scientists may create models to represent the system that they are interested in studying. Scientists must validate their ideas by testing. A model can be manipulated and adjusted far more easily than a real system. Models help scientists understand, analyze, and make predictions about systems that would be impossible to study as a whole. If a scientist wants to understand how rising CO2 levels will affect climate, it will be easier to model a smaller portion of that system. For example, he may model how higher levels of CO2 affect plant growth and the effect that will have on climate. "
a chemical equation is an example of a model.,(A) true (B) false,A,"A chemical equation is a symbolic representation of a chemical reaction. It is a shorthand way of showing how atoms are rearranged in the reaction. The general form of a chemical equation was introduced in this chapters lesson ""Introduction to Chemical Reactions."" It is: Reactants ! Products Consider the simple example in Figure 8.4. When carbon (C) reacts with oxygen (O2 ), it produces carbon dioxide (CO2 ). The chemical equation for this reaction is: C + O2 ! CO2 The reactants are one atom of carbon and one molecule of oxygen. When there is more than one reactant, they are separated by plus signs (+). The product is one molecule of carbon dioxide. If more than one product were produced, plus signs would be used between them as well. "
a road map is a three-dimensional model.,(A) true (B) false,B,"Imagine you are going on a road trip. Perhaps you are going on vacation. How do you know where to go? Most likely, you will use a map. A map is a picture of specific parts of Earths surface. There are many types of maps. Each map gives us different information. Lets look at a road map, which is the probably the most common map that you use (Figure 2.13). "
basic concepts in chemistry include,(A) atoms and molecules (B) chemical reactions (C) energy (D) all of the above,D,"Chemistry is the study of the structure, properties, and interactions of matter. Important concepts in chemistry include physical changes, such as water freezing, and chemical reactions, such as fireworks exploding. Chemistry concepts can answer all the questions on the left page of the notebook in Figure 1.5. Do you know the answers? "
which of the following changes involve(s) chemical reactions?,(A) candle burning (B) fruit spoiling (C) meat cooking (D) all of the above,D,"Not all changes in matter involve chemical reactions. For example, there are no chemical reactions involved in changes of state. When liquid water freezes or evaporates, it is still water. No bonds are broken and no new products are formed. How can you tell whether a change in matter involves a chemical reaction? Often, there is evidence. Four common signs that a chemical reaction has occurred are: Change in color: the products are a different color than the reactants. Change in temperature: heat is released or absorbed during the reaction. Production of a gas: gas bubbles are released during the reaction. Production of a solid: a solid settles out of a liquid solution. The solid is called a precipitate. You can see examples of each type of evidence in Figure 8.3 and at this URL:  MEDIA Click image to the left or use the URL below. URL: "
important physics concepts include,(A) motion (B) forces (C) energy (D) all of the above,D,"Physics is the study of energy and how it interacts with matter. Important concepts in physics include motion, forces such as magnetism and gravity, and different forms of energy. Physics concepts can answer all the questions on the right page of the notebook in Figure 1.5. "
which of the following is an example of a force?,(A) magnetism (B) motion (C) light (D) none of the above,A,"Force is defined as a push or a pull acting on an object. Examples of forces include friction and gravity. Both are covered in detail later in this chapter. Another example of force is applied force. It occurs when a person or thing applies force to an object, like the girl pushing the swing in Figure 13.1. The force of the push causes the swing to move. "
which of the following is a form of energy?,(A) gravity (B) sound (C) matter (D) two of the above,B,"The different forms of energy are defined and illustrated below. 1. Mechanical energy is the energy of movement. It is found in objects that are moving or have the potential to move. 2. Chemical energy is energy that is stored in the bonds between the atoms of compounds. If the bonds are broken, the energy is released and can be converted to other forms of energy. This portable guitar amplifier can run on batteries. Batteries store chemical energy and change it to electrical energy. 3. Electrical energy is the energy of moving electrons. Electrons flow through wires to create electric current. 4. Electromagnetic energy is energy that travels through space as electrical and magnetic waves. The light flooding the stage in the Figure 1.3 is one type of electromagnetic energy. Other types include radio waves, microwaves, X rays, and gamma rays. 5. Thermal energy is the energy of moving atoms of matter. All matter has thermal energy because atoms of all matter are constantly moving. An object with more mass has greater thermal energy than an object with less mass because it has more atoms. Why is this jogger sweating so much? His sweat is soaking up his shirt because he has so much thermal energy. Jogging is hot work because of the heat from the sun and the hard work he puts into his run. 6. Sound energy is a form of mechanical energy that starts with a vibration in matter. For example, the singers voice 7. Nuclear energy is energy that is stored in the nuclei of atoms because of the strong forces that hold the nucleus together. The energy can be released in nuclear power plants by splitting nuclei apart. It is also released when unstable (radioactive) nuclei break down, or decay. Q: The fans at a rock concert also produce or use several forms of energy. What are they? A: The fans see the concert because of electromagnetic energy (light) that enters their eyes from the well-lit musicians on stage. They hear the music because of the sound energy that reaches their ears from the amplifiers. They use mechanical energy when they clap their hands and jump from their seats in excitement. Their bodies generate thermal energy, using the chemical energy stored in food they have eaten. "
examples of screws include,(A) wood screws (B) spiral staircases (C) bottle caps (D) all of the above,D,"A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move objects to a greater depth (or higher elevation) by increasing the force applied to the screw. Many screws are used to hold things together, such as two pieces of wood or a screw cap and bottle. When you use a screw, you apply force to turn the inclined plane. The screw, in turn, applies greater force to the object, such as the wood or bottle top. Q: Can you identify the inclined plane in each example of a screw pictured in the Figure 1.1? A: The inclined plane of the screw on the left consists of the ridges, or threads, that wrap around the central cylinder of the screw. The inclined plane of the cap on the right consists of the ridges that wrap around the inner sides of the cap. "
uses of screws include,(A) raising objects (B) lowering objects (C) holding objects together (D) all of the above,D,"A screw is a simple machine that consists of an inclined plane wrapped around a central cylinder. No doubt you are familiar with screws like the wood screw in the left-hand side of the Figure 1.1. The cap of the bottle pictured on the right is another example of a screw. Screws move objects to a greater depth (or higher elevation) by increasing the force applied to the screw. Many screws are used to hold things together, such as two pieces of wood or a screw cap and bottle. When you use a screw, you apply force to turn the inclined plane. The screw, in turn, applies greater force to the object, such as the wood or bottle top. Q: Can you identify the inclined plane in each example of a screw pictured in the Figure 1.1? A: The inclined plane of the screw on the left consists of the ridges, or threads, that wrap around the central cylinder of the screw. The inclined plane of the cap on the right consists of the ridges that wrap around the inner sides of the cap. "
screws help us do work by increasing the,(A) amount of force that is applied (B) distance over which force is applied (C) speed with which force is applied (D) two of the above,A,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advantage of a screw is always greater than 1. Look at the two screws in the Figure 1.2. In the screw on the right, the threads of the inclined plane are closer together. This screw has a greater mechanical advantage and is easier to turn than the screw on the left, so it takes less force to penetrate the wood with the right screw. The trade-off is that more turns of the screw are needed to do the job because the distance over which the input force must be applied is greater. Q: Why is it harder to turn a screw with more widely spaced threads? A: The screw moves farther with each turn when the threads are more widely space, so more force must be applied to turn the screw and cover the greater distance. "
the input force is applied to the inclined plane of a screw.,(A) true (B) false,A,Two simple machines that are based on the inclined plane are the wedge and the screw. Both increase the force used to move an object because the input force is applied over a greater distance than the output force. 
the mechanical advantage of a screw is always less than 1.,(A) true (B) false,B,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advantage of a screw is always greater than 1. Look at the two screws in the Figure 1.2. In the screw on the right, the threads of the inclined plane are closer together. This screw has a greater mechanical advantage and is easier to turn than the screw on the left, so it takes less force to penetrate the wood with the right screw. The trade-off is that more turns of the screw are needed to do the job because the distance over which the input force must be applied is greater. Q: Why is it harder to turn a screw with more widely spaced threads? A: The screw moves farther with each turn when the threads are more widely space, so more force must be applied to turn the screw and cover the greater distance. "
"in the picture above, it takes it takes more turns of the screw on the right to go the same distance into the wood as the screw on the left.",(A) true (B) false,A,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. The force applied by the screw (output force) is always greater than the force applied to the screw (input force). Therefore, the mechanical advantage of a screw is always greater than 1. Look at the two screws in the Figure 1.2. In the screw on the right, the threads of the inclined plane are closer together. This screw has a greater mechanical advantage and is easier to turn than the screw on the left, so it takes less force to penetrate the wood with the right screw. The trade-off is that more turns of the screw are needed to do the job because the distance over which the input force must be applied is greater. Q: Why is it harder to turn a screw with more widely spaced threads? A: The screw moves farther with each turn when the threads are more widely space, so more force must be applied to turn the screw and cover the greater distance. "
significant figures for a measurement always include,(A) all the digits that can be read directly from the measuring device (B) one digit estimated by the person taking the measurement (C) at least two digits to the right of the decimal point (D) two of the above,D,"The examples above show that its easy to count the number of significant figures when you are making a measure- ment. But what if someone else has made the measurement? How do you know which digits are known for certain and which are estimated? How can you tell how many significant figures there are in the measurement? There are several rules for counting significant figures: Leading zeros are never significant. For example, in the number 006.1, only the 6 and 1 are significant. Zeros within a number between nonzero digits are always significant. For example, in the number 106.1, the zero is significant, so this number has four significant figures. Zeros that show only where the decimal point falls are not significant. For example, the number 470,000 has just two significant figures (4 and 7). The zeros just show that the 4 represents hundreds of thousands and the 7 represents tens of thousands. Therefore, these zeros are not significant. Trailing zeros that arent needed to show where the decimal point falls are significant. For example, 4.00 has three significant figures. Q: How many significant figures are there in each of these numbers: 20,080, 2.080, and 2000? A: Both 20,080 and 2.080 contain four significant figures, but 2000 has just one significant figure. "
assume that you take a measurement with a metric ruler that is divided into individual millimeters. which measurement has the correct number of significant figures?,(A) 21 mm (B) 210 mm (C) 2100 mm (D) none of the above,B,"Youve probably been using a ruler to measure length since you were in elementary school. But you may have made most of the measurements in English units of length, such as inches and feet. In science, length is most often measured in SI units, such as millimeters and centimeters. Many rulers have both types of units, one on each edge. The ruler pictured below has only SI units. It is shown here bigger than it really is so its easier to see the small lines, which measure millimeters. The large lines and numbers stand for centimeters. Count the number of small lines from the left end of the ruler (0.0). You should count 10 lines because there are 10 millimeters in a centimeter. Q: What is the length in millimeters of the red line above the metric ruler? A: The length of the red line is 32 mm. Q: What is the length of the red line in centimeters? A: The length of the red line is 3.2 cm. "
which of the following is a correct rule for counting significant figures?,(A) Leading zeroes are always significant (B) Zeroes between nonzero digits are not significant (C) Zeroes that show only where the decimal point falls are not significant (D) Trailing zeroes are never significant,C,"The examples above show that its easy to count the number of significant figures when you are making a measure- ment. But what if someone else has made the measurement? How do you know which digits are known for certain and which are estimated? How can you tell how many significant figures there are in the measurement? There are several rules for counting significant figures: Leading zeros are never significant. For example, in the number 006.1, only the 6 and 1 are significant. Zeros within a number between nonzero digits are always significant. For example, in the number 106.1, the zero is significant, so this number has four significant figures. Zeros that show only where the decimal point falls are not significant. For example, the number 470,000 has just two significant figures (4 and 7). The zeros just show that the 4 represents hundreds of thousands and the 7 represents tens of thousands. Therefore, these zeros are not significant. Trailing zeros that arent needed to show where the decimal point falls are significant. For example, 4.00 has three significant figures. Q: How many significant figures are there in each of these numbers: 20,080, 2.080, and 2000? A: Both 20,080 and 2.080 contain four significant figures, but 2000 has just one significant figure. "
"when measurements are used in a calculation, the answer has the same number of significant figures as the measurement with the most signficant figures.",(A) true (B) false,B,"When measurements are used in a calculation, the answer cannot have more significant figures than the measurement with the fewest significant figures. This explains why the homework answer above is wrong. It has more significant figures than the measurement with the fewest significant figures. As another example, assume that you want to calculate the volume of the block of wood shown below. The volume of the block is represented by the formula: Volume = length  width  height Therefore, you would do the following calculation: Volume = 1.2 cm  1.0 cm  1 cm = 1.2 cm3 Q: Does this answer have the correct number of significant figures? A: No, it has too many significant figures. The correct answer is 1 cm3 . Thats because the height of the block has just one significant figure. Therefore, the answer can have only one significant figure. "
work is calculated with the equation work = force/distance.,(A) true (B) false,B,Work is the use of force to move an object. It is directly related to both the force applied to the object and the distance the object moves. Work can be calculated with this equation: Work = Force x Distance. 
the output distance of a machine is always,(A) less than the input distance (B) greater than the input distance (C) equal to the input distance (D) none of the above,D,"A machine is any device that makes work easier by changing a force. Work is done whenever a force moves an object over a distance. The amount of work done is represented by the equation: Work = Force x Distance When you use a machine, you apply force to the machine. This force is called the input force. The machine, in turn, applies force to an object. This force is called the output force. The output force may or may not be the same as the input force. The force you apply to the machine is applied over a given distance, called the input distance. The force applied by the machine to the object is also applied over a distance, called the output distance. The output distance may or may not be the same as the input distance. "
a machine increases the amount of work that is done.,(A) true (B) false,B,"Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Q: If a machine increases the force applied, what does this tell you about the distance over which the force is applied by the machine: A: The machine must apply the force over a shorter distance. Thats because a machine doesnt change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease. For the same reason, if a machine increases the distance over which the force is applied, it must apply less force. "
"if a machine increases force, it must apply the force over a longer distance.",(A) true (B) false,B,"Contrary to popular belief, machines do not increase the amount of work that is done. They just change how the work is done. Machines make work easier by increasing the amount of force that is applied, increasing the distance over which the force is applied, or changing the direction in which the force is applied. Q: If a machine increases the force applied, what does this tell you about the distance over which the force is applied by the machine: A: The machine must apply the force over a shorter distance. Thats because a machine doesnt change the amount of work and work equals force times distance. Therefore, if force increases, distance must decrease. For the same reason, if a machine increases the distance over which the force is applied, it must apply less force. "
machines that increase the distance over which force is applied include,(A) steering wheels (B) pliers (C) rakes (D) two of the above,C,"Examples of machines that increase the distance over which force is applied are leaf rakes and hammers (see Figure which the force is applied, but it reduces the strength of the force. "
all sound waves begin with vibrating matter.,(A) true (B) false,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
vibrations spread through the air in all directions from a vibrating object.,(A) true (B) false,A,"All sounds begin with vibrating matter. It could be the ground vibrating when a tree comes crashing down. Or it could be guitar strings vibrating when they are plucked. You can see a guitar string vibrating in Figure 20.2. The vibrating string repeatedly pushes against the air particles next to it. The pressure of the vibrating string causes these air particles to vibrate. The air particles alternately push together and spread apart. This starts waves of vibrations that travel through the air in all directions away from the strings. The vibrations pass through the air as longitudinal waves, with individual air particles vibrating back and forth in the same direction that the waves travel. You can see an animation of sound waves moving through air at this URL: "
sound waves are,(A) surface waves (B) transverse waves (C) longitudinal waves (D) none of the above,C,"Sound is a form of energy that travels in waves. Sound waves cant travel through empty space, but they can travel through gases. Gases in the air allow us to hear most of the sounds in our world. Because of air, you can hear birds singing, horns tooting, and friends laughing. Without the atmosphere, the world would be a silent, eerie place. "
sound waves can travel only through gases.,(A) true (B) false,B,"Sound waves are mechanical waves, so they can travel only though matter and not through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could no longer be heard. Thats because the sound couldnt travel away from the clock without air particles to pass the sound energy along. You can see an online demonstration of the same experimentwith a modern twistat this URL:  (4:06). MEDIA Click image to the left or use the URL below. URL:  Sound waves can travel through many different kinds of matter. Most of the sounds we hear travel through air, but sounds can also travel through liquids such as water and solids such as glass and metal. If you swim underwater or even submerge your ears in bathwater any sounds you hear have traveled to your ears through water. You can tell that sounds travel through glass and other solids because you can hear loud outdoor sounds such as sirens through closed windows and doors. "
materials that tend to absorb rather than transmit sound waves include,(A) foam rubber (B) glass (C) metal (D) all of the above,A,"Most of the sounds we hear reach our ears through the air, but sounds can also travel through liquids and solids. If you swim underwateror even submerge your ears in bathwaterany sounds you hear have traveled to your ears through the water. Some solids, including glass and metals, are very good at transmitting sounds. Foam rubber and heavy fabrics, on the other hand, tend to muffle sounds. They absorb rather than pass on the sound energy. Q: How can you tell that sounds travel through solids? A: One way is that you can hear loud outdoor sounds such as sirens through closed windows and doors. You can also hear sounds through the inside walls of a house. For example, if you put your ear against a wall, you may be able to eavesdrop on a conversation in the next roomnot that you would, of course. "
sound waves are mechanical waves.,(A) true (B) false,A,"Sound waves are mechanical waves, so they can travel only though matter and not through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could no longer be heard. Thats because the sound couldnt travel away from the clock without air particles to pass the sound energy along. You can see an online demonstration of the same experimentwith a modern twistat this URL:  (4:06). MEDIA Click image to the left or use the URL below. URL:  Sound waves can travel through many different kinds of matter. Most of the sounds we hear travel through air, but sounds can also travel through liquids such as water and solids such as glass and metal. If you swim underwater or even submerge your ears in bathwater any sounds you hear have traveled to your ears through water. You can tell that sounds travel through glass and other solids because you can hear loud outdoor sounds such as sirens through closed windows and doors. "
visible light includes all the wavelengths of light that the human eye can detect.,(A) true (B) false,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
some animals can see infrared or ultraviolet light.,(A) true (B) false,A,"Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also depend on visible light, either directly or indirectly. Many animalsincluding predators of jellyfishuse visible light to see. Plants and certain other organisms use visible light to make food in the process of photosynthesis. Without this food, most other organisms would not be able to survive. Q: Do you think that some animals might be able to see light that isnt visible to humans? A: Some animals can see light in the infrared or ultraviolet range of wavelengths. For example, mosquitoes can see infrared light, which is emitted by warm objects. By seeing infrared light, mosquitoes can tell where the warmest, blood-rich areas of the body are located. "
objects that produce light by incandescence include,(A) candles (B) bonfires (C) oil lamps (D) all of the above,D,"An incandescent light bulb like the one pictured in the Figure 1.1 produces visible light by incandescence. Incan- descence occurs when something gets so hot that it glows. An incandescent light bulb contains a thin wire filament made of tungsten. When electric current passes through the filament, it gets extremely hot and emits light. "
substances that produce light by electroluminescence include,(A) diamond (B) emerald (C) neon (D) all of the above,C,"Some objects produce light without becoming very hot. They generate light through chemical reactions or other processes. Producing light without heat is called luminescence. Luminescence, in turn, can occur in several different ways: One type of luminescence is called fluorescence. In this process, a substance absorbs shorter-wavelength ultraviolet light and then gives off light in the visible range of wavelengths. Certain minerals produce light in this way, including gemstones such as amethyst, diamond, and emerald. Another type of luminescence is called electroluminescence. In this process, a substance gives off light when an electric current passes through it. Gases such as neon, argon, and krypton produce light by this means. The car dash lights in the Figure 1.2 are produced by electroluminescence. A third type of luminescence is called bioluminescence. This is the production of light by living things as a result of chemical reactions. The jellyfish in the opening photo above produces light by bioluminescence. So does the firefly in the Figure 1.3. Fireflies give off visible light to attract mates. "
speed determines how far something moves in a given amount of time.,(A) true (B) false,A,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
the si unit for speed is,(A) cm/s (B) m/s (C) m/h (D) km/h,B,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
"if you ride your bike 20 miles and it takes you 120 minutes, what is your average speed?",(A) 6 m/h (B) 10 m/h (C) 20 m/h (D) 60 m/h,B,"Even if speed varies during the course of a trip, its easy to calculate the average speed by using this formula: speed = distance time For example, assume you go on a car trip with your family. The total distance you travel is 120 miles, and it takes 3 hours to travel that far. The average speed for the trip is: 120 mi 3h = 40 mi/h speed = Q: Terri rode her bike very slowly to the top of a big hill. Then she coasted back down the hill at a much faster speed. The distance from the bottom to the top of the hill is 3 kilometers. It took Terri 41 hour to make the round trip. What was her average speed for the entire trip? (Hint: The round-trip distance is 6 km.) A: Terris speed can be calculated as follows: 6 km 0.25 h = 24 km/h speed = "
"if you know your average speed and how long you have been traveling, then you can calculate your distance with the formula",(A) distance = speed/time (B) distance = speed x time (C) distance = time/speed (D) none of the above,B,"If you know the average speed of a moving object, you can calculate the distance it will travel in a given period of time or the time it will take to travel a given distance. To calculate distance from speed and time, use this version of the average speed formula given above: distance = speed  time For example, if a car travels at an average speed of 60 km/h for 5 hours, then the distance it travels is: distance = 60 km/h  5 h = 300 km To calculate time from speed and distance, use this version of the formula: time = distance speed Q: If you walk 6 km at an average speed of 3 km/h, how much time does it take? A: Use the formula for time as follows: distance speed 6 km = 3 km/h =2h time = "
"to calculate the amount of time it takes to travel a given distance at a certain speed, you would use the formula",(A) time = distance/speed (B) time = distance x speed (C) time = speed/distance (D) none of the above,A,"If you know the average speed of a moving object, you can calculate the distance it will travel in a given period of time or the time it will take to travel a given distance. To calculate distance from speed and time, use this version of the average speed formula given above: distance = speed  time For example, if a car travels at an average speed of 60 km/h for 5 hours, then the distance it travels is: distance = 60 km/h  5 h = 300 km To calculate time from speed and distance, use this version of the formula: time = distance speed Q: If you walk 6 km at an average speed of 3 km/h, how much time does it take? A: Use the formula for time as follows: distance speed 6 km = 3 km/h =2h time = "
the speed of sound is faster than the speed of light.,(A) true (B) false,B,"The speed of sound is the distance that sound waves travel in a given amount of time. You probably already know that sound travels more slowly than light. Thats why you usually see the flash of lightning before you hear the boom of thunder. However, the speed of sound isnt constant. It varies depending on the medium of the sound waves. Table 20.1 lists the speed of sound in several different media. Generally, sound waves travel fastest through solids and slowest through gases. Thats because the particles of solids are close together and can quickly pass the energy of vibrations to nearby particles. You can explore the speed of sound in different media at this URL:  Medium (20C) Air Water Wood Glass Aluminum Speed of Sound Waves (m/s) 343 1437 3850 4540 6320 The speed of sound also depends on the temperature of the medium. For a given medium such as air, sound has a slower speed at lower temperatures. You can compare the speed of sound in air at different temperatures in Table transfer the energy of the sound waves. The amount of water vapor in the air affects the speed of sound as well. Do you think sound travels faster or slower when the air contains more water vapor? (Hint: Compare the speed of sound in water and air in Table 20.1.) Temperature of Air 0C 20C 100C Speed of Sound (m/s) 331 343 386 KQED: Speed of Sound Along with cable cars and seagulls, the Golden Gate Bridge foghorn is one of San Franciscos most iconic sounds. But did you know that if you hear that foghorn off in the distance, you can calculate how many miles you are from the bridge? Using the Speed of Sound exhibit at the Outdoor Exploratorium at Fort Mason, Shawn Lani shows us how sound perception is affected by distance. For more information on the speed of sound, see http://science.kqed. MEDIA Click image to the left or use the URL below. URL: "
sound waves can travel only through matter.,(A) true (B) false,A,"Sound waves are mechanical waves, so they can travel only though matter and not through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could no longer be heard. Thats because the sound couldnt travel away from the clock without air particles to pass the sound energy along. You can see an online demonstration of the same experimentwith a modern twistat this URL:  (4:06). MEDIA Click image to the left or use the URL below. URL:  Sound waves can travel through many different kinds of matter. Most of the sounds we hear travel through air, but sounds can also travel through liquids such as water and solids such as glass and metal. If you swim underwater or even submerge your ears in bathwater any sounds you hear have traveled to your ears through water. You can tell that sounds travel through glass and other solids because you can hear loud outdoor sounds such as sirens through closed windows and doors. "
sound waves generally travel most quickly through,(A) gases (B) liquids (C) solids (D) plasma,C,"Sound waves are mechanical waves, and mechanical waves can only travel through matter. The matter through which the waves travel is called the medium (plural, media). The Table 1.1 gives the speed of sound in several different media. Generally, sound waves travel most quickly through solids, followed by liquids, and then by gases. Particles of matter are closest together in solids and farthest apart in gases. When particles are closer together, they can more quickly pass the energy of vibrations to nearby particles. Medium (20  C) Dry Air Speed of Sound Waves (m/s) 343 Medium (20  C) Water Wood Glass Aluminum Speed of Sound Waves (m/s) 1437 3850 4540 6320 Q: The table gives the speed of sound in dry air. Do you think that sound travels more or less quickly through air that contains water vapor? (Hint: Compare the speed of sound in water and air in the table.) A: Sound travels at a higher speed through water than air, so it travels more quickly through air that contains water vapor than it does through dry air. "
sound waves travel more quickly through dry air than moist air.,(A) true (B) false,B,"Sound waves are mechanical waves, and mechanical waves can only travel through matter. The matter through which the waves travel is called the medium (plural, media). The Table 1.1 gives the speed of sound in several different media. Generally, sound waves travel most quickly through solids, followed by liquids, and then by gases. Particles of matter are closest together in solids and farthest apart in gases. When particles are closer together, they can more quickly pass the energy of vibrations to nearby particles. Medium (20  C) Dry Air Speed of Sound Waves (m/s) 343 Medium (20  C) Water Wood Glass Aluminum Speed of Sound Waves (m/s) 1437 3850 4540 6320 Q: The table gives the speed of sound in dry air. Do you think that sound travels more or less quickly through air that contains water vapor? (Hint: Compare the speed of sound in water and air in the table.) A: Sound travels at a higher speed through water than air, so it travels more quickly through air that contains water vapor than it does through dry air. "
the speed of sound through air is fastest when the air temperature is,(A) 0 °C (B) 20 °C (C) 40 °C (D) 60 °C,D,"The speed of sound also depends on the temperature of the medium. For a given medium, sound has a slower speed at lower temperatures. You can compare the speed of sound in dry air at different temperatures in the following Table 1.2. At a lower temperature, particles of the medium are moving more slowly, so it takes them longer to transfer the energy of the sound waves. Temperature of Air 0 C 20  C 100  C Speed of Sound Waves (m/s) 331 343 386 Q: What do you think the speed of sound might be in dry air at a temperature of -20  C? A: For each 1 degree Celsius that temperature decreases, the speed of sound decreases by 0.6 m/s. So sound travels through dry, -20  C air at a speed of 319 m/s. "
electric charges can travel easily through dry air.,(A) true (B) false,B,"Static electricity is a buildup of electric charges on objects. Charges build up when negative electrons are transferred from one object to another. The object that gives up electrons becomes positively charged, and the object that accepts the electrons becomes negatively charged. This can happen in several ways. One way electric charges can build up is through friction between materials that differ in their ability to give up or accept electrons. When you wipe your rubber-soled shoes on the wool mat, for example, electrons rub off the mat onto your shoes. As a result of this transfer of electrons, positive charges build up on the mat and negative charges build up on you. Once an object becomes electrically charged, it is likely to remain charged until it touches another object or at least comes very close to another object. Thats because electric charges cannot travel easily through air, especially if the air is dry. Q: Youre more likely to get a shock in the winter when the air is very dry. Can you explain why? A: When the air is very dry, electric charges are more likely to build up objects because they cannot travel easily through the dry air. This makes a shock more likely when you touch another object. "
lighting can occur between a cloud and,(A) another part of the same cloud (B) a different cloud (C) the ground (D) any of the above,D,"So much energy collects in cumulonimbus clouds that a huge release of electricity, called lightning, may result (Figure 1.4). The electrical discharge may be between one part of the cloud and another, two clouds, or a cloud and the ground. Lightning heats the air so that it expands explosively. The loud clap is thunder. Light waves travel so rapidly that lightning is seen instantly. Sound waves travel much more slowly, so a thunderclap may come many seconds after the lightning is spotted. Lightning behind the town of Diamond Head, Hawaii. "
lightning is an example of static discharge.,(A) true (B) false,A,"Another example of static discharge, but on a much larger scale, is lightning. You can see how it occurs in the following diagram (Figure 1.1). During a rainstorm, clouds develop regions of positive and negative charge due to the movement of air molecules, water drops, and ice particles. The negative charges are concentrated at the base of the clouds, and the positive charges are concentrated at the top. The negative charges repel electrons on the ground beneath them, so the ground below the clouds becomes positively charged. At first, the atmosphere prevents electrons from flowing away from areas of negative charge and toward areas of positive charge. As more charges build up, however, the air between the oppositely charged areas also becomes charged. When this happens, static electricity is discharged as bolts of lightning. "
"during a rainstorm, negative charges become concentrated at the",(A) surface of the ground (B) top of the clouds (C) base of the clouds (D) two of the above,C,"Another example of static discharge, but on a much larger scale, is lightning. You can see how it occurs in the following diagram (Figure 1.1). During a rainstorm, clouds develop regions of positive and negative charge due to the movement of air molecules, water drops, and ice particles. The negative charges are concentrated at the base of the clouds, and the positive charges are concentrated at the top. The negative charges repel electrons on the ground beneath them, so the ground below the clouds becomes positively charged. At first, the atmosphere prevents electrons from flowing away from areas of negative charge and toward areas of positive charge. As more charges build up, however, the air between the oppositely charged areas also becomes charged. When this happens, static electricity is discharged as bolts of lightning. "
a surface wave is one type of mechanical wave.,(A) true (B) false,A,"There are three types of mechanical waves. They differ in how they travel through a medium. The three types are transverse, longitudinal, and surface waves. All three types are described in detail below. "
an ocean wave is an example of a surface wave.,(A) true (B) false,A,"A surface wave is a wave that travels along the surface of a medium. The medium is the matter through which the wave travels. Ocean waves are the best-known examples of surface waves. They travel on the surface of the water between the ocean and the air. Q: What do you think causes ocean waves? A: Most ocean waves are caused by wind blowing across the water. Moving air molecules transfer some of their energy to molecules of ocean water. The energy travels across the surface of the water in waves. The stronger the winds are blowing, the larger the waves are and the more energy they have. "
"in deep water, how do particles of water move when a surface wave passes through them?",(A) up and down (B) back and forth (C) in an overall circular motion (D) all of the above,D,"In deep water, particles of water just move in circles. They dont actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. Look at the Figure 1.2. You can see how the waves start to drag on the bottom in shallow water. This creates friction that slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. The difference in speed causes the waves to get steeper until they topple over and break. The crashing waves carry water onto the shore as surf. Q: In this diagram of a wave breaking near shore, where do you think a surfer would try to catch the wave? A: The surfer would try to catch the wave where it starts to steepen and lean forward toward the shore. "
why do surface waves break along the shore?,(A) The waves start to drag on the bottom (B) The tops of the waves speed up (C) The waves become less steep (D) all of the above,A,"In deep water, particles of water just move in circles. They dont actually move closer to shore with the energy of the waves. However, near the shore where the water is shallow, the waves behave differently. Look at the Figure 1.2. You can see how the waves start to drag on the bottom in shallow water. This creates friction that slows down the bottoms of the waves, while the tops of the waves keep moving at the same speed. The difference in speed causes the waves to get steeper until they topple over and break. The crashing waves carry water onto the shore as surf. Q: In this diagram of a wave breaking near shore, where do you think a surfer would try to catch the wave? A: The surfer would try to catch the wave where it starts to steepen and lean forward toward the shore. "
"the larger a surface wave is, the more energy the wave has.",(A) true (B) false,A,"All waves are the way energy travels through matter. Ocean waves are energy traveling through water. They form when wind blows over the surface of the ocean. Wind energy is transferred to the sea surface. Then, the energy is carried through the water by the waves. Figure 10.11 shows ocean waves crashing against rocks on a shore. They pound away at the rocks and anything else they strike. Three factors determine the size of ocean waves: 1. The speed of the wind. 2. The length of time the wind blows. 3. The distance the wind blows. The faster, longer, and farther the wind blows, the bigger the waves are. Bigger waves have more energy. "
an ocean wave carries water all the way across the ocean to the opposite shore.,(A) true (B) false,B,"Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Figure 14.9 shows how water molecules move when a wave goes by. "
which of the following is not a synthesis reaction?,(A) 2H2 + O2 → 2H2O (B) 2CO + O2 → 2CO2 (C) 3H2 + N2 → 2NH3 (D) Mg + 2HCl → MgCl2 + H2,D,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
the chemical equation 2no + o2  2no2 represents a synthesis reaction.,(A) true (B) false,A,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+BC In this equation, the letters A and B represent the reactants that begin the reaction, and the letter C represents the product that is synthesized in the reaction. The arrow shows the direction in which the reaction occurs. Q: What is the chemical equation for the synthesis of nitrogen dioxide (NO2 ) from nitric oxide (NO) and oxygen (O2 )? A: The equation for this synthesis reaction is: 2NO + O2  2NO2 "
the product of a synthesis reaction can be an element or a compound.,(A) true (B) false,B,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
examples of synthesis reactions include,(A) 2K + Cl2 → 2KCl (B) Zn + 2HCl → ZnCl2 + H2 (C) Cl2 + 2KBr → 2KCl + Br2 (D) two of the above,A,"A synthesis reaction occurs when two or more reactants combine to form a single product. A synthesis reaction can be represented by the general equation: A+B !C In this general equation (and others like it in this lesson), the letters A, B,C, and so on represent atoms or ions of elements. The arrow shows the direction of the reaction. The letters on the left side of the arrow are the reactants that begin the chemical reaction. The letters on the right side of the arrow are the product of the reaction. Two examples of synthesis reactions are described below. You can see more examples at this URL: "
physical constraints on technological design include,(A) scientific laws (B) ease of use (C) safety (D) cost,A,"Technological design always has constraints. Constraints are limits on the design. Common constraints include: laws of nature, such as the law of gravity. properties of the materials used. cost of producing a technology. Ethical concerns are also constraints on many technological designs. Like scientists, engineers must follow ethical rules. For example, the technologies they design must be as safe as possible for people and the environment. Engineers must weigh the benefits and risks of new technologies, and the benefits should outweigh the risks. "
technology can have both positive and negative effects on people.,(A) true (B) false,A,"Important new technologies such as the wheel have had a big impact on human society. Major advances in technol- ogy have influenced every aspect of life, including transportation, food production, manufacturing, communication, medicine, and the arts. Thats because technology has the goal of solving human problems, so new technologies usually make life better. They may make work easier, for example, or make people healthier. Sometimes, however, new technologies affect people in negative ways. For example, using a new product or process might cause human health problems or pollute the environment. Q: Can you think of a modern technology that has both positive and negative effects on people? A: Modern methods of transportation have both positive and negative effects on people. They help people and goods move quickly all over the world. However, most of them pollute the environment. For example, gasoline-powered cars and trucks add many pollutants to the atmosphere. The pollutants harm peoples health and contribute to global climate change. "
how did the industrial revolution affect society?,(A) New cities grew up around factories (B) Living conditions in cities improved (C) Average income decreased (D) Population size decreased,A,"Few technologies have impacted society as greatly as the powerful steam engine developed by Scottish inventor James Watt in 1775 (see Figure 1.1). Watts steam engine was soon being used to power all kinds of machines. It started a revolution in industry. For the first time in history, people did not have to rely on human or animal muscle, wind, or water for power. With the steam engine to power machines, new factories sprang up all over Britain. The Industrial Revolution began in Britain the late 1700s. It eventually spread throughout Western Europe, North America, Japan, and many other countries. It marked a major turning point in human history. Almost every aspect of daily life was influenced by it in some way. Average income and population both began to grow faster than ever before. People flocked to the new factories for jobs, and densely populated towns and cities grew up around the factories. The new towns and cities were crowded, and soot from the factories polluted the air. You can see an example of this in the Figure 1.2. This made living conditions very poor. Working conditions in the factories were also bad, with long hours and the pace set by machines. Even young children worked in the factories, damaging their health and giving them little opportunity for education or play. Q: In addition to factory machines, the steam engine was used to power farm machinery, trains, and ships. What effects might this have had on peoples lives? A: Farm machinery replaced human labor and allowed fewer people to produce more food. This is why many rural people migrated to the new towns and cities to look for work in factories. Steam-powered trains and ships made it easier for people to migrate. Food and factory goods could also be transported on steam-powered trains and ships, making them available to far more people. "
thermal conduction occurs more quickly in certain solids and liquids than in gases.,(A) true (B) false,A,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
good thermal conductors include,(A) aluminum (B) plastic (C) wood (D) two of the above,A,"Conduction is usually faster in liquids and certain solids than in gases. Materials that are good conductors of thermal energy are called thermal conductors. Metals are excellent thermal conductors. They have freely moving electrons that can transfer energy quickly and easily. Thats why the metal pot in Figure 18.5 soon gets hot all over, even though it gains thermal energy from the fire only at the bottom of the pot. In Figure 18.6, the metal heating element of the curling iron heats up almost instantly and quickly transfers energy to the strands of hair that it touches. "
"when you wear a down jacket, it prevents the transfer of cold from the outside air to your body.",(A) true (B) false,B,"One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators. Down-filled snowsuits, like those in the Figure 1.2, are good thermal insulators because their feather filling traps a lot of air. Another example of a thermal insulator is pictured in the Figure 1.3. The picture shows fluffy pink insulation inside the attic of a home. Like the down filling in a snowsuit, the insulation traps a lot of air. The insulation helps to prevent the transfer of thermal energy into the house on hot days and out of the house on cold days. Other materials that are thermal insulators include plastic and wood. Thats why pot handles and cooking utensils are often made of these materials. Notice that the outside of the toaster pictured in the opening image is made of plastic. The plastic casing helps prevent the transfer of thermal energy from the heating element inside to the outer surface of the toaster where it could cause burns. Q: Thermal insulators have many practical uses besides the uses mentioned above. Can you think of others? A: Thermal insulators are often used to keep food or drinks hot or cold. For example, Styrofoam coolers and thermos containers are used for these purposes. "
good thermal insulators include,(A) air (B) Styrofoam (C) iron (D) two of the above,D,"One way to retain your own thermal energy on a cold day is to wear clothes that trap air. Thats because air, like other gases, is a poor conductor of thermal energy. The particles of gases are relatively far apart, so they dont bump into each other or into other things as often as the more closely spaced particles of liquids or solids. Therefore, particles of gases have fewer opportunities to transfer thermal energy. Materials that are poor thermal conductors are called thermal insulators. Down-filled snowsuits, like those in the Figure 1.2, are good thermal insulators because their feather filling traps a lot of air. Another example of a thermal insulator is pictured in the Figure 1.3. The picture shows fluffy pink insulation inside the attic of a home. Like the down filling in a snowsuit, the insulation traps a lot of air. The insulation helps to prevent the transfer of thermal energy into the house on hot days and out of the house on cold days. Other materials that are thermal insulators include plastic and wood. Thats why pot handles and cooking utensils are often made of these materials. Notice that the outside of the toaster pictured in the opening image is made of plastic. The plastic casing helps prevent the transfer of thermal energy from the heating element inside to the outer surface of the toaster where it could cause burns. Q: Thermal insulators have many practical uses besides the uses mentioned above. Can you think of others? A: Thermal insulators are often used to keep food or drinks hot or cold. For example, Styrofoam coolers and thermos containers are used for these purposes. "
only matter that feels warm has thermal energy.,(A) true (B) false,B,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
the thermal energy of matter depends on its,(A) mass (B) temperature (C) number of particles (D) all of the above,D,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
an object with a lower temperature always has less thermal energy than an object with a warmer temperature.,(A) true (B) false,B,"Something that has a high temperature is said to be hot. Does temperature measure heat? Is heat just another word for thermal energy? The answer to both questions is no. Heat is the transfer of thermal energy between objects that have different temperatures. Thermal energy always moves from an object with a higher temperature to an object with a lower temperature. When thermal energy is transferred in this way, the warm object becomes cooler and the cool object becomes warmer. Sooner or later, both objects will have the same temperature. Only then does the transfer of thermal energy end. For a visual explanation of these concepts, watch the animation ""Temperature vs. Heat"" at this URL:  . "
which choice has the least thermal energy?,(A) cup of hot cocoa (B) bathtub full of warm water (C) swimming pool full of cool water (D) all the water in Earth’s oceans,A,"Thermal energy and temperature are closely related. Both reflect the kinetic energy of moving particles of matter. However, temperature is the average kinetic energy of particles of matter, whereas thermal energy is the total kinetic energy of particles of matter. Does this mean that matter with a lower temperature has less thermal energy than matter with a higher temperature? Not necessarily. Another factor also affects thermal energy. The other factor is mass. Q: Look at the pot of soup and the tub of water in the Figure 1.1. Which do you think has greater thermal energy? A: The soup is boiling hot and has a temperature of 100  C, whereas the water in the tub is just comfortably warm, with a temperature of about 38  C. Although the water in the tub has a much lower temperature, it has greater thermal energy. The particles of soup have greater average kinetic energy than the particles of water in the tub, explaining why the soup has a higher temperature. However, the mass of the water in the tub is much greater than the mass of the soup in the pot. This means that there are many more particles of water than soup. All those moving particles give the water in the tub greater total kinetic energy, even though their average kinetic energy is less. Therefore, the water in the tub has greater thermal energy than the soup. Q: Could a block of ice have more thermal energy than a pot of boiling water? A: Yes, the block of ice could have more thermal energy if its mass was much greater than the mass of the boiling water. "
"the faster the particles of matter are moving, the greater their kinetic energy is.",(A) true (B) false,A,The particles that make up matter are also constantly moving. They have kinetic energy. The theory that all matter consists of constantly moving particles is called the kinetic theory of matter. You can learn more about it at the URL below. 
"the slower the particles of matter are moving, the lower their temperature is.",(A) true (B) false,A,"No doubt you already have a good idea of what temperature is. You might say that its how warm or cool something feels. In physics, temperature is defined as the average kinetic energy of the particles of matter. When particles of matter move more quickly, they have more kinetic energy, so their temperature is higher. With a higher temperature, matter feels warmer. When particles move more slowly, they have less kinetic energy on average, so their temperature is lower. With a lower temperature, matter feels cooler. "
thermal energy is the total kinetic energy of moving particles of matter.,(A) true (B) false,A,"The atoms that make up matter are in constant motion, so they have kinetic energy. All that motion gives matter thermal energy. Thermal energy is defined as the total kinetic energy of all the atoms that make up an object. It depends on how fast the atoms are moving and how many atoms the object has. Therefore, an object with more mass has greater thermal energy than an object with less mass, even if their individual atoms are moving at the same speed. You can see an example of this in Figure 17.13. "
examples of thermal radiation include thermal energy traveling through,(A) the air from a campfire to you (B) empty space from the sun to Earth (C) a metal pan to water inside the pan (D) two of the above,D,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
no matter is required to transfer thermal energy by,(A) conduction (B) convection (C) radiation (D) two of the above,C,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
only very hot objects radiate thermal energy.,(A) true (B) false,B,"Both conduction and convection transfer energy through matter. Radiation is the only way of transferring energy that doesnt require matter. Radiation is the transfer of energy by waves that can travel through empty space. When the waves reach objects, they transfer energy to the objects, causing them to warm up. This is how the suns energy reaches Earth and heats its surface (see Figure 18.10). Radiation is also how thermal energy from a campfire warms people nearby. You might be surprised to learn that all objects radiate thermal energy, including people. In fact, when a room is full of people, it may feel noticeably warmer because of all the thermal energy the people radiate! To learn more about thermal radiation, watch ""Radiation"" at the URL below. "
life on earth depends on thermal energy radiated from the sun.,(A) true (B) false,A,Almost all energy on Earth comes from the Sun. The Suns energy heats the planet and the air around it. Sunlight also powers photosynthesis and life on Earth. 
thomson won a nobel prize for his discovery of protons.,(A) true (B) false,B,"John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the atom. Thomson was born in England and studied at Cambridge University, where he later became a professor. In 1906, he won the Nobel Prize in physics for his research on how gases conduct electricity. This research also led to his discovery of the electron. You can see a picture of Thomson 1.1. "
thomson knew that the particles he discovered were smaller than atoms because of their,(A) charge (B) color (C) mass (D) volume,C,"John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the atom. Thomson was born in England and studied at Cambridge University, where he later became a professor. In 1906, he won the Nobel Prize in physics for his research on how gases conduct electricity. This research also led to his discovery of the electron. You can see a picture of Thomson 1.1. "
thomson thought that the positive charges in an atom were,(A) concentrated in the nucleus (B) clumped into small clusters like plums (C) spread throughout the atom (D) none of the above,C,"Thomson knew that atoms are neutral in electric charge. So how could atoms contain negative particles? Thomson thought that the rest of the atom must be positive to cancel out the negative charge. He said that an atom is like a plum pudding, which has plums scattered through it. Thats why Thomsons model of the atom is called the plum pudding model. You can see it in Figure 5.11. It shows the atom as a sphere of positive charge (the pudding) with negative electrons (the plums) scattered through it. "
thomsons research proved daltons earlier claim about the smallest particles of matter.,(A) true (B) false,B,"John Dalton discovered atoms in 1804. He thought they were the smallest particles of matter, which could not be broken down into smaller particles. He envisioned them as solid, hard spheres. It wasnt until 1897 that a scientist named Joseph John (J. J.) Thomson discovered that there are smaller particles within the atom. Thomson was born in England and studied at Cambridge University, where he later became a professor. In 1906, he won the Nobel Prize in physics for his research on how gases conduct electricity. This research also led to his discovery of the electron. You can see a picture of Thomson 1.1. "
all atoms are neutral in electric charge.,(A) true (B) false,A,"Atoms are neutral in electric charge because they have the same number of electrons as protons. However, atoms may transfer electrons and become charged ions, as illustrated in Figure 23.5. Positively charged ions, or cations, form when atoms give up electrons. Negatively charged ions, or anions, form when atoms gain electrons. Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons either between two materials or within a material. Three ways this can occur are friction, conduction, and polarization. In all cases, the total charge remains the same. Electrons move, but they arent destroyed. This is the law of conservation of charge. "
the formation of charged matter always depends on the transfer of electrons.,(A) true (B) false,A,"Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons, either between two materials or within a material. Three ways this can occur are referred to as conduction, polarization, and friction. All three ways are described below. However, regardless of how electrons are transferred, the total charge always remains the same. Electrons move, but they arent destroyed. This is the law of conservation of charge. "
ways that matter can become electrically charged include,(A) conduction (B) convection (C) radiation (D) all of the above,A,"Like the formation of ions, the formation of charged matter in general depends on the transfer of electrons, either between two materials or within a material. Three ways this can occur are referred to as conduction, polarization, and friction. All three ways are described below. However, regardless of how electrons are transferred, the total charge always remains the same. Electrons move, but they arent destroyed. This is the law of conservation of charge. "
conduction occurs when you,(A) touch a van de Graaff generator (B) rub a balloon on your hair (C) reach toward a metal doorknob (D) two of the above,A,"To understand how conduction works, you need to think about the tiny particles that make up matter. The particles of all matter are in constant random motion, but the particles of warmer matter have more energy and move more quickly than the particles of cooler matter. When particles of warmer matter collide with particles of cooler matter, they transfer some of their thermal energy to the cooler particles. From particle to particle, like dominoes falling, thermal energy moves through matter. In the opening photo above, conduction occurs between particles of metal in the cookie sheet and anything cooler that comes into contact with ithopefully, not someones bare hands! "
polarization occurs only when there is direct contact between two objects.,(A) true (B) false,B,"Polarization is the movement of electrons within a neutral object due to the electric field of a nearby charged object. It occurs without direct contact between the two objects. You can see how it happens in Figure 23.8. When the negatively charged plastic rod in the figure is placed close to the neutral metal plate, electrons in the plate are repelled by the positive charges in the rod. The electrons move away from the rod, causing one side of the plate to become positively charged and the other side to become negatively charged. Polarization may also occur after you walk across a wool carpet in rubber-soled shoes and become negatively charged. If you reach out to touch a metal doorknob, electrons in the neutral metal will be repelled and move away from your hand before you even touch the knob. In this way, one end of the doorknob becomes positively charged and the other end becomes negatively charged. "
electrons are transferred whenever there is friction between materials that differ in their ability to give up or accept electrons.,(A) true (B) false,A,"Another way electrons may be transferred is through conduction. This occurs when there is direct contact between materials that differ in their ability to give up or accept electrons. For example, wool tends to give up electrons and rubber tends to accept them. Therefore, when you walk across a wool carpet in rubber-soled shoes, electrons transfer from the carpet to your shoes. You become negatively charged, while the carpet becomes positively charged. Another example of conduction is pictured in Figure 23.7. The device this girl is touching is called a van de Graaff generator. The dome on top is negatively charged. When the girl places her hand on the dome, electrons are transferred to her, so she becomes negatively charged as well. Even the hairs on her head become negatively charged. As a result, individual hairs repel each other, causing them to stand on end. You can see a video demonstration of a van de Graff generator at this URL:  . "
"of all known elements, transition metals make up about",(A) 80 percent (B) 60 percent (C) 40 percent (D) 20 percent,B,"Transition metals are all the elements in groups 3-12 of the periodic table. In the periodic table pictured in Figure known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the opening image). Q: Transition metals have been called the most typical of all metals. What do you think this means? A: Unlike some other metals, transition metals have the properties that define the metals class. They are excellent conductors of electricity, for example, and they also have luster, malleability, and ductility. You can read more about these properties of transition metals below. "
transition metals include,(A) aluminum (B) barium (C) cobalt (D) all of the above,C,"Transition metals are all the elements in groups 3-12 of the periodic table. In the periodic table pictured in Figure known elements. In addition to copper (Cu), well known examples of transition metals include iron (Fe), zinc (Zn), silver (Ag), and gold (Au) (Copper (Cu) is pictured in its various applications in the opening image). Q: Transition metals have been called the most typical of all metals. What do you think this means? A: Unlike some other metals, transition metals have the properties that define the metals class. They are excellent conductors of electricity, for example, and they also have luster, malleability, and ductility. You can read more about these properties of transition metals below. "
which of the following is not a property of most transition metals?,(A) malleability (B) ability to conduct electricity (C) ability to conduct heat (D) low melting point,D,"Transition metals are superior conductors of heat as well as electricity. They are malleable, which means they can be shaped into sheets, and ductile, which means they can be shaped into wires. They have high melting and boiling points, and all are solids at room temperature, except for mercury (Hg), which is a liquid. Transition metals are also high in density and very hard. Most of them are white or silvery in color, and they are generally lustrous, or shiny. The compounds that transition metals form with other elements are often very colorful. You can see several examples in the Figure 1.2. Some properties of transition metals set them apart from other metals. Compared with the alkali metals in group 1 and the alkaline Earth metals in group 2, the transition metals are much less reactive. They dont react quickly with water or oxygen, which explains why they resist corrosion. Q: How is the number of valence electrons typically related to the properties of elements? A: The number of valence electrons usually determines how reactive elements are as well as the ways in which they react with other elements. "
transition metals are high in density and very hard.,(A) true (B) false,A,"Transition metals are superior conductors of heat as well as electricity. They are malleable, which means they can be shaped into sheets, and ductile, which means they can be shaped into wires. They have high melting and boiling points, and all are solids at room temperature, except for mercury (Hg), which is a liquid. Transition metals are also high in density and very hard. Most of them are white or silvery in color, and they are generally lustrous, or shiny. The compounds that transition metals form with other elements are often very colorful. You can see several examples in the Figure 1.2. Some properties of transition metals set them apart from other metals. Compared with the alkali metals in group 1 and the alkaline Earth metals in group 2, the transition metals are much less reactive. They dont react quickly with water or oxygen, which explains why they resist corrosion. Q: How is the number of valence electrons typically related to the properties of elements? A: The number of valence electrons usually determines how reactive elements are as well as the ways in which they react with other elements. "
most transition metals are dull and brown in color.,(A) true (B) false,B,"Groups 3-12 of the periodic table contain transition metals (see Figure 6.11). Transition metals have more valence electrons and are less reactive than metals in the first two metal groups. The transition metals are shiny. Many are silver colored. They tend to be very hard, with high melting and boiling points. All except mercury (Hg) are solids at room temperature. Transition metals include the elements that are placed below the periodic table. Those that follow lanthanum (La) are called lanthanides. They are all shiny, relatively reactive metals. Those that follow Actinium (Ac) are called actinides. They are all radioactive metals. This means they are unstable. They break down into different, more stable elements. You can read more about radioactive elements in the chapter Nuclear Chemistry. Many of the actinides do not occur in nature but are made in laboratories. "
a mechanical wave is a wave that travels through matter.,(A) true (B) false,A,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
the matter a mechanical wave travels through is called the medium.,(A) true (B) false,A,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
examples of transverse waves include the wave that travels through a,(A) guitar string when you pluck it (B) spring toy when you shake it from side to side (C) bungee cord when you shake it up and down (D) all of the above,D,"A transverse wave is a wave in which the medium vibrates at right angles to the direction that the wave travels. An example of a transverse wave is a wave in a rope, like the one pictured in Figure 19.2. In this wave, energy is provided by a persons hand moving one end of the rope up and down. The direction of the wave is down the length of the rope away from the persons hand. The rope itself moves up and down as the wave passes through it. You can see a brief video of a transverse wave in a rope at this URL:  . To see a transverse wave in slow motion, go to this URL:  (0:22). MEDIA Click image to the left or use the URL below. URL: "
earthquake waves travel in all directions away from the disturbance that causes the earthquake.,(A) true (B) false,A,"Seismic waves are the energy from earthquakes. Seismic waves move outward in all directions away from their source. Each type of seismic wave travels at different speeds in different materials. All seismic waves travel through rock, but not all travel through liquid or gas. Geologists study seismic waves to learn about earthquakes and the Earths interior. "
s waves travel through underground rocks.,(A) true (B) false,A,Transverse waves called S waves occur during earthquakes. The disturbance that causes an earthquake sends transverse waves through underground rocks in all directions away from the disturbance. S waves may travel for hundreds of miles. An S wave is modeled in the Figure 1.3. 
types of friction include,(A) static friction (B) sliding friction (C) rolling friction (D) all of the above,D,"Friction is the force that opposes motion between any surfaces that are in contact. There are four types of friction: static, sliding, rolling, and fluid friction. Static, sliding, and rolling friction occur between solid surfaces. Fluid friction occurs in liquids and gases. All four types of friction are described below. "
static friction prevents you from slipping when you walk on a sidewalk.,(A) true (B) false,A,"Static friction acts on objects when they are resting on a surface. For example, if you are walking on a sidewalk, there is static friction between your shoes and the concrete each time you put down your foot (see Figure 13.12). Without this static friction, your feet would slip out from under you, making it difficult to walk. Static friction also allows you to sit in a chair without sliding to the floor. Can you think of other examples of static friction? "
sliding friction is stronger than static friction.,(A) true (B) false,B,"Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. Thats why its easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil and when you put on your bikes brakes. "
factors that affect the amount of friction against an object moving through the air include the objects,(A) speed (B) weight (C) temperature (D) two of the above,A,"Fluid friction is friction that acts on objects that are moving through a fluid. A fluid is a substance that can flow and take the shape of its container. Fluids include liquids and gases. If youve ever tried to push your open hand through the water in a tub or pool, then youve experienced fluid friction between your hand and the water. When a skydiver is falling toward Earth with a parachute, fluid friction between the parachute and the air slows the descent (see Figure 13.14). Fluid pressure with the air is called air resistance. The faster or larger a moving object is, the greater is the fluid friction resisting its motion. The very large surface area of a parachute, for example, has greater air resistance than a skydivers body. "
"when you put on the brakes of your bike, the wheels stop turning. then friction between the wheels and the road slows your bike to a stop. which type of friction is this?",(A) fluid friction (B) static friction (C) sliding friction (D) rolling friction,C,"Sliding friction is friction that acts on objects when they are sliding over a surface. Sliding friction is weaker than static friction. Thats why its easier to slide a piece of furniture over the floor after you start it moving than it is to get it moving in the first place. Sliding friction can be useful. For example, you use sliding friction when you write with a pencil. The pencil lead slides easily over the paper, but theres just enough friction between the pencil and paper to leave a mark. Q: How does sliding friction help you ride a bike? A: There is sliding friction between the brake pads and bike rims each time you use your bikes brakes. This friction slows the rolling wheels so you can stop. "
some animals use echolocation to find prey.,(A) true (B) false,A,"Animals such as bats and dolphins send out ultrasound waves and use their echoes, or reflected waves, to identify the locations of objects they cannot see. This is called echolocation. Animals use echolocation to find prey and avoid running into objects in the dark. You can see in the Figure 1.1 how a bat uses echolocation to find insect prey. "
sonar is used to determine the,(A) speed of motor vehicles (B) distance to underwater objects (C) location of approaching storms (D) all of the above,B,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
you can calculate distance from speed and time with the equation,(A) Distance = Speed/Time (B) Distance = Time/Speed (C) Distance = Speed x Time (D) none of the above,C,"If you know the average speed of a moving object, you can calculate the distance it will travel in a given period of time or the time it will take to travel a given distance. To calculate distance from speed and time, use this version of the average speed formula given above: distance = speed  time For example, if a car travels at an average speed of 60 km/h for 5 hours, then the distance it travels is: distance = 60 km/h  5 h = 300 km To calculate time from speed and distance, use this version of the formula: time = distance speed Q: If you walk 6 km at an average speed of 3 km/h, how much time does it take? A: Use the formula for time as follows: distance speed 6 km = 3 km/h =2h time = "
the speed of sound waves through ocean water is 1437 m/s. assume that ultrasound waves take 2 seconds to travel from a sonar device on a ship to the bottom of the water and back to the ship again. how deep is the water?,(A) 2874 m (B) 1437 m (C) 718 m (D) none of the above,B,"Sonar uses ultrasound in a way that is similar to echolocation. Sonar stands for sound navigation and ranging. It is used to locate underwater objects such as sunken ships or to determine how deep the water is. A sonar device is usually located on a boat at the surface of the water. The device is both a sender and a receiver (see Figure 20.14). It sends out ultrasound waves and detects reflected waves that bounce off underwater objects or the bottom of the water. If you watch the video at the URL below, you can see how sonar is used on a submarine. The distance to underwater objects or the bottom of the water can be calculated from the known speed of sound in water and the time it takes for the waves to travel to the object. The equation for the calculation is: Distance = Speed  Time Assume, for example, that a sonar device on a ship sends an ultrasound wave to the bottom of the ocean. The speed of the sound through ocean water is 1437 m/s, and the wave travels to the bottom and back in 2 seconds. What is the distance from the surface to the bottom of the water? The sound wave travels to the bottom and back in 2 seconds, so it travels from the surface to the bottom in 1 second. Therefore, the distance from the surface to the bottom is: Distance = 1437 m/s  1 s = 1437 m You Try It! Problem: The sonar device on a ship sends an ultrasound wave to the bottom of the water at speed of 1437 m/s. The wave is reflected back to the device in 4 seconds. How deep is the water? "
the use of reflected ultrasound waves to create images of organs inside the body is called ultrasonography.,(A) true (B) false,A,"Another use of ultrasound is to see inside the human body. This use of ultrasound is called ultrasonography. Harmless ultrasound waves are sent inside the body, and the reflected waves are used to create an image on a screen. This technology is used to examine internal organs and unborn babies without risk to the patient. You can see a doctor using ultrasound in the Figure 1.3. "
the smallest alkene is methene.,(A) true (B) false,B,"Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced by most fruits and vegetables. It speeds up ripening and also rotting. Figure 9.11 shows the effects of ethene on bananas. Like alkanes, alkenes can have different shapes. They can form straight chains, branched chains, or rings. Alkenes can also form isomers, or compounds with the same atoms but different shapes. Generally, the physical properties of alkenes are similar to those of alkanes. Smaller alkenes, such as ethene, have relatively high boiling and melting points. They are gases at room temperature. Larger alkenes have lower boiling and melting points. They are liquids or waxy solids at room temperature. "
smaller alkenes are gases at room temperature.,(A) true (B) false,A,"Unsaturated hydrocarbons that contain at least one double bond are called alkenes. The name of a specific alkene always ends in ene, with a prefix indicating the number of carbon atoms. Figure 9.10 shows the structural formula for the smallest alkene. It has just two carbon atoms and is named ethene. Ethene is produced by most fruits and vegetables. It speeds up ripening and also rotting. Figure 9.11 shows the effects of ethene on bananas. Like alkanes, alkenes can have different shapes. They can form straight chains, branched chains, or rings. Alkenes can also form isomers, or compounds with the same atoms but different shapes. Generally, the physical properties of alkenes are similar to those of alkanes. Smaller alkenes, such as ethene, have relatively high boiling and melting points. They are gases at room temperature. Larger alkenes have lower boiling and melting points. They are liquids or waxy solids at room temperature. "
which statement about aromatic hydrocarbons is true?,(A) They have only single bonds (B) They have branched-chain shapes (C) They have strong scents (D) two of the above,C,"Unsaturated hydrocarbons called aromatic hydrocarbons are cyclic hydrocarbons that have double bonds. These compounds have six carbon atoms in a ring with alternating single and double bonds. The smallest aromatic hydrocarbon is benzene, which has just one ring. Its structural formula is shown in the Figure 1.2. Larger aromatic hydrocarbons consist of two or more rings, which are joined together by bonds between their carbon atoms. The name of aromatic hydrocarbons comes from their strong aroma, or scent. Thats why they are used in air fresheners and mothballs. A: Each carbon atom forms four covalent bonds. Carbon atoms always form four covalent bonds, regardless of the atoms to which it bonds. "
alkynes are very common in nature.,(A) true (B) false,B,"Unsaturated hydrocarbons that contain at least one triple bond are called alkynes. The name of specific alkynes always end in yne, with a prefix for the number of carbon atoms. Figure 9.12 shows the smallest alkyne, called ethyne, which has just two carbon atoms. Ethyne is also called acetylene. It is burned in acetylene torches, like the one in Figure 9.13. Acetylene produces so much heat when it burns that it can melt metal. Breaking all those bonds between carbon atoms releases a lot of energy. Alkynes may form straight or branched chains. They rarely occur as cycloalkynes. In fact, alkynes of all shapes are relatively rare, at least in nature. "
which chemical formula represents an alkyne?,(A) CH4 (B) C2H6 (C) C2H4 (D) C2H2,D,"Unsaturated hydrocarbons that contain one or more triple bonds are called alkynes. The names of specific alkynes always end in -yne and have a prefix for the number of carbon atoms. The structural formula in the Figure 1.3 represents the smallest alkyne, named ethyne, which has two carbon atoms and two hydrogen atoms (C2 H2 ). Ethyne is also called acetylene. It is burned in acetylene torches, like the one pictured in the Figure 1.4. The flame of an acetylene torch is so hot that it can melt metal. Cutting metal with an acetylene (ethyne) torch. Alkynes may form straight or branched chains. They rarely occur in ring shapes. In fact, alkynes of all shapes are relatively rare in nature. "
earth has north and south magnetic poles like a bar magnet.,(A) true (B) false,A,"Imagine a huge bar magnet passing through Earths axis, as illustrated in Figure 24.10. This is a good representation of Earth as a magnet. Like a bar magnet, Earth has north and south magnetic poles and a magnetic field. "
how does earths magnetic field protect the planet?,(A) It holds the atmosphere in place (B) It deflects solar winds (C) It protects Earth’s organisms from radiation (D) two of the above,D,"Earths magnetic field helps protect Earth and its organisms from harmful particles given off by the sun. Most of the particles are attracted to the north and south magnetic poles, where Earths magnetic field is strongest. This is also where relatively few organisms live. Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural ""compasses"" that work just as well. Birds like the garden warbler in Figure 24.16 use Earths magnetic field to guide their annual migrations. Recent research suggests that warblers and other migrating birds have structures in their eyes that let them see Earths magnetic field as a visual pattern. You can learn more about animals and Earths magnetic field, including the potential effects of magnetic field reversals, at this URL:  . "
there would be no northern lights without the magnetosphere.,(A) true (B) false,A,"When massive solar storms cause the Van Allen belts to become overloaded with particles, the result is the most spectacular feature of the ionosphere  the nighttime aurora (Figure 1.1). The particles spiral along magnetic field lines toward the poles. The charged particles energize oxygen and nitrogen gas molecules, causing them to light up. Each gas emits a particular color of light. (a) Spectacular light displays are visible as the aurora borealis or northern lights in the Northern Hemisphere. (b) The aurora australis or southern lights encircles Antarctica. What would Earths magnetic field look like if it were painted in colors? It would look like the aurora! This QUEST video looks at the aurora, which provides clues about the solar wind, Earths magnetic field and Earths atmosphere. Click image to the left or use the URL below. URL: "
animals that use earths magnetic field for navigation include,(A) loggerhead turtles (B) migratory birds (C) humans (D) all of the above,D,"Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field and uses it to navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for navigation. Recent research suggests that they may have structures in their eyes that let them see Earths magnetic field as a visual pattern. "
people have only recently started using earths magnetic field for determining direction.,(A) true (B) false,B,"Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field and uses it to navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for navigation. Recent research suggests that they may have structures in their eyes that let them see Earths magnetic field as a visual pattern. "
some birds may be able to sense earths magnetic field lines as a visual pattern.,(A) true (B) false,A,"Another benefit of Earths magnetic field is its use for navigation. People use compasses to detect Earths magnetic north pole and tell direction. Many animals have natural compasses that work just as well. For example, the loggerhead turtle in the Figure 1.2 senses the direction and strength of Earths magnetic field and uses it to navigate along migration routes. Many migratory bird species can also sense the magnetic field and use it for navigation. Recent research suggests that they may have structures in their eyes that let them see Earths magnetic field as a visual pattern. "
"valence electrons tend to be attracted by the nuclei of other atoms as much as, or more than, the nucleus of their own atom.",(A) true (B) false,A,"Valence electrons are the electrons in the outer energy level of an atom that can participate in interactions with other atoms. Valence electrons are generally the electrons that are farthest from the nucleus. As a result, they may be attracted as much or more by the nucleus of another atom than they are by their own nucleus. "
all the elements in the same period of the periodic table have the same number of valence electrons.,(A) true (B) false,B,"The number of valence electrons in an atom is reflected by its position in the periodic table of the elements (see the periodic table in the Figure 1.1). Across each row, or period, of the periodic table, the number of valence electrons in groups 1-2 and 13-18 increases by one from one element to the next. Within each column, or group, of the table, all the elements have the same number of valence electrons. This explains why all the elements in the same group have very similar chemical properties. For elements in groups 1-2 and 13-18, the number of valence electrons is easy to tell directly from the periodic table. This is illustrated in the simplified periodic table in the Figure 1.2. It shows just the numbers of valence electrons in each of these groups. For elements in groups 3-12, determining the number of valence electrons is more complicated. Q: Based on both periodic tables above (Figures 1.1 and 1.2), what are examples of elements that have just one valence electron? What are examples of elements that have eight valence electrons? How many valence electrons does oxygen (O) have? A: Any element in group 1 has just one valence electron. Examples include hydrogen (H), lithium (Li), and sodium (Na). Any element in group 18 has eight valence electrons (except for helium, which has a total of just two electrons). Examples include neon (Ne), argon (Ar), and krypton (Kr). Oxygen, like all the other elements in group 16, has six valence electrons. "
what is the maximum number of valence electrons an element may have?,(A) 6 (B) 8 (C) 10 (D) 12,B,"The smallest atoms are hydrogen atoms. They have just one electron orbiting the nucleus. That one electron is in the first energy level. Bigger atoms have more electrons. Electrons are always added to the lowest energy level first until it has the maximum number of electrons possible. Then electrons are added to the next higher energy level until that level is full, and so on. How many electrons can a given energy level hold? The maximum numbers of electrons possible for the first four energy levels are shown in the Figure 1.1. For example, energy level I can hold a maximum of two electrons, and energy level II can hold a maximum of eight electrons. The maximum number depends on the number of orbitals at a given energy level. An orbital is a volume of space within an atom where an electron is most likely to be found. As you can see by the images in the Figure 1.2, some orbitals are shaped like spheres (S orbitals) and some are shaped like dumbbells (P orbitals). There are other types of orbitals as well. Regardless of its shape, each orbital can hold a maximum of two electrons. Energy level I has just one orbital, so two electrons will fill this energy level. Energy level II has four orbitals, so it takes eight electrons to fill this energy level. Q: Energy level III can hold a maximum of 18 electrons. How many orbitals does this energy level have? A: At two electrons per orbital, this energy level must have nine orbitals. "
when a group 1 element reacts it,(A) gains two electrons (B) loses two electrons (C) gains one electron (D) loses one electron,D,"The halogens are among the most reactive of all elements, although reactivity declines from the top to the bottom of the halogen group. Because all halogens have seven valence electrons, they are eager to gain one more electron. Doing so gives them a full outer energy level, which is the most stable arrangement of electrons. Halogens often combine with alkali metals in group 1 of the periodic table. Alkali metals have just one valence electron, which they are equally eager to donate. Reactions involving halogens, especially halogens near the top of the group, may be explosive. You can see some examples in the video below. (Warning: Dont try any of these reactions at home!) Click image to the left or use the URL below. URL: "
which element would you expect to gain one electron in a chemical reaction?,(A) chlorine (B) oxygen (C) nitrogen (D) carbon,A,"It takes energy to remove valence electrons from an atom. The force of attraction between the negative electrons and positive nucleus must be overcome. The amount of energy needed depends on the element. Less energy is needed to remove just one or a few electrons than many. This explains why sodium and other alkali metals form positive ions so easily. Less energy is also needed to remove electrons from larger atoms in the same group. For example, in group 1, it takes less energy to remove an electron from francium (Fr) at the bottom of the group than from lithium (Li) at the top of the group (see Figure 7.4). In bigger atoms, valence electrons are farther from the nucleus. As a result, the force of attraction between the electrons and nucleus is weaker. What happens when an atom gains an electron and becomes a negative ion? Energy is released. Halogens release the most energy when they form ions. As a result, they are very reactive. "
velocity is a vector.,(A) true (B) false,A,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
"if you represent velocity with an arrow, the length of the arrow represents",(A) speed (B) distance (C) direction (D) acceleration,A,"Speed tells you only how fast or slow an object is moving. It doesnt tell you the direction the object is moving. The measure of both speed and direction is called velocity. Velocity is a vector. A vector is measurement that includes both size and direction. Vectors are often represented by arrows. When using an arrow to represent velocity, the length of the arrow stands for speed, and the way the arrow points indicates the direction. Click image to the left or use the URL below. URL: "
the si unit for velocity is km/h.,(A) true (B) false,B,"How fast or slow something moves is its speed. Speed determines how far something travels in a given amount of time. The SI unit for speed is meters per second (m/s). Speed may be constant, but often it varies from moment to moment. "
the steepness of a line graph is called its slope.,(A) true (B) false,A,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
"if a velocity-time graph is horizontal, then velocity is",(A) increasing (B) decreasing (C) not changing (D) accelerating,C,"In a position-time graph, the velocity of the moving object is represented by the slope, or steepness, of the graph line. If the graph line is horizontal, like the line after time = 5 seconds in Graph 2 in the Figure 1.2, then the slope is zero and so is the velocity. The position of the object is not changing. The steeper the line is, the greater the slope of the line is and the faster the objects motion is changing. "
"in the graph described in question 5, acceleration is",(A) zero (B) positive (C) less than 1 (D) none of the above,A,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
"in the graph in question 8, acceleration between seconds 2 and 4 is 10 m/s.",(A) true (B) false,B,"In a velocity-time graph, acceleration is represented by the slope, or steepness, of the graph line. If the line slopes upward, like the line between 0 and 4 seconds in the Figure 1.1, velocity is increasing, so acceleration is positive. If the line is horizontal, as it is between 4 and 7 seconds, velocity is constant and acceleration is zero. If the line slopes downward, like the line between 7 and 10 seconds, velocity is decreasing and acceleration is negative. Negative acceleration is called deceleration. Q: Assume that another sprinter is running the same race. The other runner reaches a top velocity of 9 m/s by 4 seconds after the start of the race. How would the first 4 seconds of the velocity-time graph for this runner be different from the Figure 1.1? A: The graph line for this runner during seconds 0-4 would be steeper (have a greater slope). This would show that acceleration is greater during this time period for the other sprinter. "
a clear image is produced by diffuse reflection.,(A) true (B) false,B,"If a surface is extremely smooth, like very still water, then an image formed by reflection is sharp and clear. This is called regular reflection. If the surface is even slightly rough, an image may not form, or if there is an image, it is blurry or fuzzy. This is called diffuse reflection. Both types of reflection are represented in Figure 22.10. You can also see animations of both types of reflection at this URL: http://toolboxes.flexiblelearning.net.au/demosites/serie In Figure 22.10, the waves of light are represented by arrows called rays. Rays that strike the surface are referred to as incident rays, and rays that reflect off the surface are known as reflected rays. In regular reflection, all the rays are reflected in the same direction. This explains why regular reflection forms a clear image. In diffuse reflection, in contrast, the rays are reflected in many different directions. This is why diffuse reflection forms, at best, a blurry image. "
regular reflection occurs when the reflective surface is very smooth.,(A) true (B) false,A,"Reflection of light occurs when light bounces back from a surface that it cannot pass through. Reflection may be regular or diffuse. If the surface is very smooth, like a mirror, the reflected light forms a very clear image. This is called regular, or specular, reflection. In the Figure 1.1, the smooth surface of the still water in the pond on the left reflects light in this way. When light is reflected from a rough surface, the waves of light are reflected in many different directions, so a clear image does not form. This is called diffuse reflection. In the Figure 1.1, the ripples in the water in the picture on the right cause diffuse reflection of the blooming trees. "
when light passes from one medium into another it may,(A) change direction (B) change speed (C) be refracted (D) all of the above,D,"Transmission of light occurs when light passes through matter. As light is transmitted, it may pass straight through matter or it may be refracted or scattered as it passes through. When light is refracted, it changes direction as it passes into a new medium and changes speed. The straw in the Figure 1.2 looks bent where light travels from water to air. Light travels more quickly in air than in water and changes direction. Scattering occurs when light bumps into tiny particles of matter and spreads out in all directions. In the Figure air, giving the headlights a halo appearance. Q: What might be another example of light scattering? A: When light passes through smoky air, it is scattered by tiny particles of soot. "
"when light is absorbed, it transfers its energy to matter.",(A) true (B) false,A,"Light may transfer its energy to matter rather than being reflected or transmitted by matter. This is called absorption. When light is absorbed, the added energy increases the temperature of matter. If you get into a car that has been sitting in the sun all day, the seats and other parts of the cars interior may be almost too hot to touch, especially if they are black or very dark in color. Thats because dark colors absorb most of the sunlight that strikes them. Q: In hot sunny climates, people often dress in light-colored clothes. Why is this a good idea? A: Light-colored clothes absorb less light and reflect more light than dark-colored clothes, so they keep people cooler. "
what happens to light that strikes transparent matter?,(A) It is reflected (B) It is absorbed (C) It is transmitted (D) none of the above,C,"When visible light strikes matter, it interacts with it. How light interacts with matter depends on the type of matter. "
matter is opaque if it,(A) absorbs light (B) reflects light (C) transmits light (D) two of the above,D,"Matter can be classified on the basis of its interactions with light. Matter may be transparent, translucent, or opaque. An example of each type of matter is pictured in the Figure 1.4. Transparent matter is matter that transmits light without scattering it. Examples of transparent matter include air, pure water, and clear glass. You can see clearly through transparent objects, such as the top panes of the window 1.4, because just about all of the light that strikes them passes through to the other side. Translucent matter is matter that transmits light but scatters the light as it passes through. Light passes through translucent objects but you cannot see clearly through them because the light is scattered in all directions. The frosted glass panes at the bottom of the window 1.4 are translucent. Opaque matter is matter that does not let any light pass through it. Matter may be opaque because it absorbs light, reflects light, or does some combination of both. Examples of opaque objects are objects made of wood, like the shutters in the Figure 1.5. The shutters absorb most of the light that strikes them and reflect just a few wavelengths of visible light. The glass mirror 1.5 is also opaque. Thats because it reflects all of the light that strikes it. "
"the sclera is the opaque, white, outer covering of the eye.",(A) true (B) false,A,"The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps light out of the eye except at the center front of the eye. The cornea is a transparent outer covering of the front of the eye. It protects the eye and also acts as a convex lens. A convex lens is thicker in the middle than at the edges and makes rays of light converge, or meet at a point. The shape of the cornea helps focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. All the light passes through it instead. The pupil controls the amount of light that enters the eye. It automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens of the eye is a convex lens. It fine-tunes the focus so an image forms on the retina at the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not dim light. There are three different types of cones. Each type senses one of the three primary colors of light (red, green, or blue). The optic nerve carries electrical signals from the rods and cones to the brain. Q: The lens of the eye is a convex lens. How would vision be affected if the lens of the eye was concave instead of convex? A: A concave lens causes rays of light to diverge, or spread apart. It forms a virtual image on the same side of the lens at the object being viewed. Therefore, a concave lens would focus the image in front of the eye, not on the retina inside the eye. No signals would be sent to the brain so vision would not be possible. "
the lens is the only structure in the eye that focuses light.,(A) true (B) false,B,"The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps light out of the eye except at the center front of the eye. The cornea is a transparent outer covering of the front of the eye. It protects the eye and also acts as a convex lens. A convex lens is thicker in the middle than at the edges and makes rays of light converge, or meet at a point. The shape of the cornea helps focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. All the light passes through it instead. The pupil controls the amount of light that enters the eye. It automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens of the eye is a convex lens. It fine-tunes the focus so an image forms on the retina at the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not dim light. There are three different types of cones. Each type senses one of the three primary colors of light (red, green, or blue). The optic nerve carries electrical signals from the rods and cones to the brain. Q: The lens of the eye is a convex lens. How would vision be affected if the lens of the eye was concave instead of convex? A: A concave lens causes rays of light to diverge, or spread apart. It forms a virtual image on the same side of the lens at the object being viewed. Therefore, a concave lens would focus the image in front of the eye, not on the retina inside the eye. No signals would be sent to the brain so vision would not be possible. "
which of the following statements about the cornea is false?,(A) It is transparent (B) It helps focus light (C) It helps protect the eye (D) none of the above,D,"The human eye is an organ that is specialized to collect light and focus images. The structures of the human eye are shown in the Figure 1.1. Examine each structure in the diagram as you read about it below. The sclera, also known as the white of the eye, is an opaque outer covering that protects the eye. It keeps light out of the eye except at the center front of the eye. The cornea is a transparent outer covering of the front of the eye. It protects the eye and also acts as a convex lens. A convex lens is thicker in the middle than at the edges and makes rays of light converge, or meet at a point. The shape of the cornea helps focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. All the light passes through it instead. The pupil controls the amount of light that enters the eye. It automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens of the eye is a convex lens. It fine-tunes the focus so an image forms on the retina at the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not dim light. There are three different types of cones. Each type senses one of the three primary colors of light (red, green, or blue). The optic nerve carries electrical signals from the rods and cones to the brain. Q: The lens of the eye is a convex lens. How would vision be affected if the lens of the eye was concave instead of convex? A: A concave lens causes rays of light to diverge, or spread apart. It forms a virtual image on the same side of the lens at the object being viewed. Therefore, a concave lens would focus the image in front of the eye, not on the retina inside the eye. No signals would be sent to the brain so vision would not be possible. "
which structure controls the amount of light that enters the eye?,(A) retina (B) lens (C) pupil (D) none of the above,C,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
the membrane lining the back of the eye is the,(A) cornea (B) sclera (C) retina (D) optic nerve,C,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
rods are nerve cells that sense different colors of light.,(A) true (B) false,B,"The structure of the human eye is shown in Figure 22.24. Find each structure in the diagram as you read about it below. The cornea is the transparent outer covering of the eye. It protects the eye and also acts as a convex lens, helping to focus light that enters the eye. The pupil is an opening in the front of the eye. It looks black because it doesnt reflect any light. It allows light to enter the eye. The pupil automatically gets bigger or smaller to let more or less light in as needed. The iris is the colored part of the eye. It controls the size of the pupil. The lens is a convex lens that fine-tunes the focus so an image forms on the back of the eye. Tiny muscles control the shape of the lens to focus images of close or distant objects. The retina is a membrane lining the back of the eye. The retina has nerve cells called rods and cones that change images to electrical signals. Rods are good at sensing dim light but cant distinguish different colors of light. Cones can sense colors but not in dim light. There are three different types of cones. Each type senses one of the three primary colors of light. The optic nerve carries electrical signals from the rods and cones to the brain. "
the vision problem called myopia is also called farsightedness.,(A) true (B) false,B,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
"in myopia, images focus",(A) in front of the retina (B) behind the retina (C) above the retina (D) on the retina,A,"Myopia is also called nearsightedness. It affects about one third of people. People with myopia can see nearby objects clearly, but distant objects appear blurry. The picture below shows how a person with myopia might see two boys that are a few meters away ( Figure 1.1). In myopia, the eye is too long. Below, you can see how images are focused on the retina of someone with myopia ( Figure 1.2). Myopia is corrected with a concave lens, which curves inward like the inside of a bowl. The lens changes the focus, so images fall on the retina as they should. Generally, nearsightedness first occurs in school-age children. There is some evidence that myopia is inherited. If one or both of your parents need glasses, there is an increased chance that you will too. Individuals who spend a lot of time reading, working or playing at a computer, or doing other close visual work may also be more likely to develop nearsightedness. Because the eye continues to grow during childhood, myopia typically progresses until On the left, you can see how a person with normal vision sees two boys. The right image shows how a person with myopia sees the boys. The eye of a person with myopia is longer than normal. As a result, images are focused in front of the retina (top left). A concave lens is used to correct myopia to help focus images on the retina (top right). Farsightedness, or hyperopia, oc- curs when objects are focused in back of the retina (bottom left). It is corrected with a convex lens (bottom right). about age 20. However, nearsightedness may also develop in adults due to visual stress or health conditions such as diabetes. A common sign of nearsightedness is difficulty seeing distant objects like a movie screen or the TV, or the whiteboard or chalkboard in school. Eyeglasses or contact lenses can easily help with myopia. Depending on the amount of myopia, you may only need to wear glasses or contact lenses for certain activities, like watching a movie or driving a car. Or, if you are very nearsighted, they may need to be worn all the time. "
the vision problem called hyperopia is also called nearsightedness.,(A) true (B) false,B,"You probably know people who need eyeglasses or contact lenses to see clearly. Maybe you need them yourself. Lenses are used to correct vision problems. Two of the most common vision problems in young people are myopia and hyperopia. You can compare myopia and hyperopia in Figure 20.13. To learn about astigmatism, another common vision problem, watch this very short video:  . MEDIA Click image to the left or use the URL below. URL:  Myopia is commonly called nearsightedness. People with myopia can see nearby objects clearly, but distant objects appear blurry. Myopia occurs when images focus in front of the retina because the eyeball is too long. This vision problem can be corrected with concave lenses, which curve inward. The lenses focus images correctly on the retina. Hyperopia is commonly called farsightedness. People with hyperopia can see distant objects clearly, but nearby objects appear blurry. Hyperopia occurs when images focus in back of the retina because the eyeball is too short. This vision problem can be corrected with convex lenses, which curve outward. The lenses focus images correctly on the retina. "
"in hyperopia, the eyeball is",(A) longer than normal (B) shorter than normal (C) smaller than normal (D) larger than normal,B,"Farsightedness, or hyperopia, is the condition in which distant objects are seen clearly, but nearby objects appear blurry. It occurs when the eyeball is shorter than normal (see Figure 1.2). This causes images to be focused in a spot that would fall behind the retina (if light could pass through the retina). Hyperopia can be corrected with convex lenses. The lenses focus images farther forward in the eye, so they fall on the retina instead of behind it. Q: Joey has hyperopia. When is he more likely to need his glasses: when he reads a book or when he watches TV? A: With hyperopia, Joey is farsighted. He can probably see the TV more clearly than the words in a book because the TV is farther away. Therefore, he is more likely to need his glasses when he reads than when he watches TV. "
all waves that travel through matter are called,(A) longitudinal waves (B) mechanical waves (C) transverse waves (D) surface waves,B,"The energy of a mechanical wave can travel only through matter. This matter is called the medium (plural, media). The medium in Figure 19.1 is a liquid the water in the pond. But the medium of a mechanical wave can be any state of matter, including a solid or a gas. Its important to note that particles of matter in the medium dont actually travel along with the wave. Only the energy travels. The particles of the medium just vibrate, or move back-and- forth or up-and-down in one spot, always returning to their original positions. As the particles vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. "
the matter a wave travels through is called the material of the wave.,(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
"the more energy a wave has, the farther the particles of matter move.",(A) true (B) false,A,"Waves that travel through mattersuch as the fabric of a flagare called mechanical waves. The matter they travel through is called the medium. When the energy of a wave passes through the medium, particles of the medium move. The more energy the wave has, the farther the particles of the medium move. The distance the particles move is measured by the waves amplitude. "
the position of a particle of matter in the absence of a wave is called the,(A) trough (B) midline (C) resting position (D) normal location,C,"In the 1920s, physicists discovered that electrons do not travel in fixed paths. In fact, they found that electrons only have a certain chance of being in any particular place. They could only describe where electrons are with mathematical formulas. Thats because electrons have wave-like properties as well as properties of particles of matter. It is the ""wave nature"" of electrons that lets them exist only at certain distances from the nucleus. The negative electrons are attracted to the positive nucleus. However, because the electrons behave like waves, they bend around the nucleus instead of falling toward it. Electrons exist only where the wave is stable. These are the orbitals. They do not exist where the wave is not stable. These are the places between orbitals. "
a wave with greater energy has a larger amplitude.,(A) true (B) false,A,A wave caused by a disturbance with more energy has greater amplitude. Imagine dropping a small pebble into a pond of still water. Tiny ripples will move out from the disturbance in concentric circles. The ripples are low- amplitude waves with very little energy. Now imagine throwing a big boulder into the pond. Very large waves will be generated by the disturbance. These waves are high-amplitude waves and have a great deal of energy. 
"in all mechanical waves, particles of the medium move up and down when the wave passes through them.",(A) true (B) false,B,"The energy of a mechanical wave can travel only through matter. The matter through which the wave travels is called the medium (plural, media). The medium in the water wave pictured above is water, a liquid. But the medium of a mechanical wave can be any state of matter, even a solid. Q: How do the particles of the medium move when a wave passes through them? A: The particles of the medium just vibrate in place. As they vibrate, they pass the energy of the disturbance to the particles next to them, which pass the energy to the particles next to them, and so on. Particles of the medium dont actually travel along with the wave. Only the energy of the wave travels through the medium. "
a wave with a higher frequency has a longer wavelength.,(A) true (B) false,B,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
the frequency of a wave is the same as the frequency of vibrations that caused the wave.,(A) true (B) false,A,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
"for waves of the same amplitude, a higher frequency wave has less energy than a shorter frequency wave.",(A) true (B) false,B,"The frequency of a wave is the same as the frequency of the vibrations that caused the wave. For example, to generate a higher-frequency wave in a rope, you must move the rope up and down more quickly. This takes more energy, so a higher-frequency wave has more energy than a lower-frequency wave with the same amplitude. You can see examples of different frequencies in the Figure 1.2 (Amplitude is the distance that particles of the medium move when the energy of a wave passes through them.) "
"if 20 waves pass a fixed point in 10 seconds, the frequency of the waves is",(A) 200 Hz (B) 100 Hz (C) 20 Hz (D) 2 Hz,D,"The number of waves that pass a fixed point in a given amount of time is wave frequency. Wave frequency can be measured by counting the number of crests (high points) of waves that pass the fixed point in 1 second or some other time period. The higher the number is, the greater the frequency of the waves. The SI unit for wave frequency is the hertz (Hz), where 1 hertz equals 1 wave passing a fixed point in 1 second. The Figure 1.1 shows high-frequency and low-frequency transverse waves. Q: The wavelength of a wave is the distance between corresponding points on adjacent waves. For example, it is the distance between two adjacent crests in the transverse waves in the diagram. Infer how wave frequency is related to wavelength. "
the frequency of four different waves is listed below. which wave has the most energy?,(A) 2000 Hz (B) 1000 Hz (C) 200 Hz (D) 20 Hz,A,"As you can see in the Figure 1.1, gamma rays have the shortest wavelengths and highest frequencies of all electromagnetic waves. Their wavelengths are shorter than the diameter of atomic nuclei, and their frequencies are greater than 1019 hertz (Hz). Thats 10 quadrillion waves per second! Because of their high frequencies, gamma rays are also the most energetic of all electromagnetic waves. "
wave interactions refer to interactions between a wave and,(A) another wave (B) its reflected wave (C) its medium (D) none of the above,C,"Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction. Each type of interaction is described in detail below. For animations of the three types of wave interactions, go to this URL: "
types of wave interactions include,(A) reflection (B) refraction (C) diffraction (D) all of the above,D,"Waves interact with matter in several ways. The interactions occur when waves pass from one medium to another. Besides bouncing back like an echo, waves may bend or spread out when they strike a new medium. These three ways that waves may interact with matter are called reflection, refraction, and diffraction. Each type of interaction is described in detail below. For animations of the three types of wave interactions, go to this URL: "
only sound waves can be reflected.,(A) true (B) false,B,"Sound waves are mechanical waves, so they can travel only though matter and not through empty space. This was demonstrated in the 1600s by a scientist named Robert Boyle. Boyle placed a ticking clock in a sealed glass jar. The clock could be heard ticking through the air and glass of the jar. Then Boyle pumped the air out of the jar. The clock was still running, but the ticking could no longer be heard. Thats because the sound couldnt travel away from the clock without air particles to pass the sound energy along. You can see an online demonstration of the same experimentwith a modern twistat this URL:  (4:06). MEDIA Click image to the left or use the URL below. URL:  Sound waves can travel through many different kinds of matter. Most of the sounds we hear travel through air, but sounds can also travel through liquids such as water and solids such as glass and metal. If you swim underwater or even submerge your ears in bathwater any sounds you hear have traveled to your ears through water. You can tell that sounds travel through glass and other solids because you can hear loud outdoor sounds such as sirens through closed windows and doors. "
refraction occurs because waves change speed in a new medium.,(A) true (B) false,A,"Refraction is another way that waves interact with matter. Refraction occurs when waves bend as they enter a new medium at an angle. You can see an example of refraction in Figure 19.17. Light bends when it passes from air to water. The bending of the light causes the pencil to appear broken. Why do waves bend as they enter a new medium? Waves usually travel at different speeds in different media. For example, light travels more slowly in water than air. This causes it to refract when it passes from air to water. "
wave diffraction depends on the,(A) size of the obstacle or opening (B) wavelength of the waves (C) speed of the waves (D) two of the above,D,"Did you ever notice that when youre walking down a street, you can hear sounds around the corners of buildings? Figure 19.18 shows why this happens. As you can see from the figure, sound waves spread out and travel around obstacles. This is called diffraction. It also occurs when waves pass through an opening in an obstacle. All waves may be diffracted, but it is more pronounced in some types of waves than others. For example, sound waves bend around corners much more than light does. Thats why you can hear but not see around corners. For a given type of waves, such as sound waves, how much the waves diffract depends on two factors: the size of the obstacle or opening in the obstacle and the wavelength. This is illustrated in Figure 19.19. Diffraction is minor if the length of the obstacle or opening is greater than the wavelength. Diffraction is major if the length of the obstacle or opening is less than the wavelength. "
wave interference refers to wave interactions that can occur between a wave and,(A) another wave (B) its reflected wave (C) its medium (D) two of the above,D,"Waves interact not only with matter in the ways described above. Waves also interact with other waves. This is called wave interference. Wave interference may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. How amplitude is affected depends on the type of interference. Interference can be constructive or destructive. "
"when two waves pass through each other in opposite directions, the interference affects their",(A) amplitude (B) frequency (C) wavelength (D) two of the above,A,"Waves interact not only with matter in the ways described above. Waves also interact with other waves. This is called wave interference. Wave interference may occur when two waves that are traveling in opposite directions meet. The two waves pass through each other, and this affects their amplitude. How amplitude is affected depends on the type of interference. Interference can be constructive or destructive. "
constructive interference occurs when the crests of one wave overlap the troughs of the other wave.,(A) true (B) false,B,"Constructive interference occurs when the crests, or highest points, of one wave overlap the crests of the other wave. You can see this in the Figure 1.1. As the waves pass through each other, the crests combine to produce a wave with greater amplitude. "
destructive interference occurs when the crests of two waves overlap.,(A) true (B) false,B,"Destructive interference occurs when the crests of one wave overlap the troughs, or lowest points, of another wave. The Figure 1.2 shows what happens. As the waves pass through each other, the crests and troughs cancel each other out to produce a wave with zero amplitude. "
standing waves form only when waves reflect at a 90-degree angle.,(A) true (B) false,A,"Waves may reflect off an obstacle that they are unable to pass through. When waves are reflected straight back from an obstacle, the reflected waves interfere with the original waves and create standing waves. These are waves that appear to be standing still. Standing waves occur because of a combination of constructive and destructive interference. Q: How could you use a rope to produce standing waves? A: You could tie one end of the rope to a fixed object, such as doorknob, and move the other end up and down to generate waves in the rope. When the waves reach the fixed object, they are reflected back. The original waves and the reflected waves interfere to produce a standing wave. Try it yourself and see if the waves appear to stand still. "
"before einstein, all scientists thought that electromagnetic energy consists of waves.",(A) true (B) false,B,"In 1905, the physicist Albert Einstein developed a new theory about electromagnetic radiation. The theory is often called the wave-particle theory. It explains how electromagnetic radiation can behave as both a wave and a particle. Einstein argued that when an electron returns to a lower energy level and gives off electromagnetic energy, the energy is released as a discrete packet of energy. We now call such a packet of energy a photon. According to Einstein, a photon resembles a particle but moves like a wave. You can see this in the Figure 1.1. The theory posits that waves of photons traveling through space or matter make up electromagnetic radiation. "
einstein based his wave-particle theory on experimental evidence.,(A) true (B) false,B,"After Einstein proposed his theory, evidence was discovered to support it. For example, scientists shone laser light through two slits in a barrier made of a material that blocked light. You can see the setup of this type of experiment in the Figure 1.2. Using a special camera that was very sensitive to light, they took photos of the light that passed through the slits. The photos revealed tiny pinpoints of light passing through the double slits. This seemed to show that light consists of particles. However, if the camera was exposed to the light for a long time, the pinpoints accumulated in bands that resembled interfering waves. Therefore, the experiment showed that light seems to consist of particles that act like waves. "
the double-slit experiments showed that light,(A) consists of particles (B) behaves like a wave (C) requires a medium (D) two of the above,D,"After Einstein proposed his theory, evidence was discovered to support it. For example, scientists shone laser light through two slits in a barrier made of a material that blocked light. You can see the setup of this type of experiment in the Figure 1.2. Using a special camera that was very sensitive to light, they took photos of the light that passed through the slits. The photos revealed tiny pinpoints of light passing through the double slits. This seemed to show that light consists of particles. However, if the camera was exposed to the light for a long time, the pinpoints accumulated in bands that resembled interfering waves. Therefore, the experiment showed that light seems to consist of particles that act like waves. "
photons create interference patterns just as waves do.,(A) true (B) false,A,"After Einstein proposed his theory, evidence was discovered to support it. For example, scientists shone laser light through two slits in a barrier made of a material that blocked light. You can see the setup of this type of experiment in the Figure 1.2. Using a special camera that was very sensitive to light, they took photos of the light that passed through the slits. The photos revealed tiny pinpoints of light passing through the double slits. This seemed to show that light consists of particles. However, if the camera was exposed to the light for a long time, the pinpoints accumulated in bands that resembled interfering waves. Therefore, the experiment showed that light seems to consist of particles that act like waves. "
speed can be calculated with the equation,(A) Speed = Distance x Time (B) Speed = Distance/Time (C) Speed = Time/Distance (D) none of the above,B,"If you know the speed of a moving object, you can also calculate the distance it will travel in a given amount of time. To do so, you would use this version of the general speed formula: distance = speed  time For example, if a car travels at a speed of 60 km/h for 2 hours, then the distance traveled is: distance = 60 km/h  2 h = 120 km You Try It! Problem: If Maria runs at a speed of 2 m/s, how far will she run in 60 seconds? "
"which equation correctly shows the relationship between wave speed, wavelength, and wave frequency?",(A) Wave Speed = Wavelength x Wave Frequency (B) Wave Speed = Wavelength/Wave Frequency (C) Wave Speed = Wave Frequency/Wavelength (D) none of the above,A,"Wave speed is related to both wavelength and wave frequency. Wavelength is the distance between two correspond- ing points on adjacent waves. Wave frequency is the number of waves that pass a fixed point in a given amount of time. This equation shows how the three factors are related: Speed = Wavelength x Wave Frequency In this equation, wavelength is measured in meters and frequency is measured in hertz (Hz), or number of waves per second. Therefore, wave speed is given in meters per second, which is the SI unit for speed. Q: If you increase the wavelength of a wave, does the speed of the wave increase as well? A: Increasing the wavelength of a wave doesnt change its speed. Thats because when wavelength increases, wave frequency decreases. As a result, the product of wavelength and wave frequency is still the same speed. Click image to the left or use the URL below. URL: "
"light always travels at the same speed, but it can have different frequencies and wavelengths. if the frequency of light decreases, its wavelength",(A) increases (B) decreases (C) stays the same (D) may increase or decrease,A,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
"the wavelengths of four different waves are listed below. if all four waves have the same speed, which wave has the highest frequency?",(A) Wave A: 0001 m (B) Wave B: 001 m (C) Wave C: 01 m (D) Wave D: 10 m,A,"Although all electromagnetic waves travel at the same speed, they may differ in their wavelength and frequency. "
the speed of most waves depends on the medium.,(A) true (B) false,A,"The speed of most waves depends on the medium, or the matter through which the waves are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle through the medium. Click image to the left or use the URL below. URL: "
waves generally travel fastest through gases and slowest through solids.,(A) true (B) false,B,"The speed of most waves depends on the medium through which they are traveling. Generally, waves travel fastest through solids and slowest through gases. Thats because particles are closest together in solids and farthest apart in gases. When particles are farther apart, it takes longer for the energy of the disturbance to pass from particle to particle. "
the wavelength of visible light determines its color.,(A) true (B) false,A,"Visible light is light that has wavelengths that can be detected by the human eye. The wavelength of visible light determines the color that the light appears. As you can see in the Figure 1.1, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between are all the other colors of light that we can see. Only seven main colors of light are actually represented in the diagram. "
wavelength usually is measured in meters.,(A) true (B) false,A,"Wavelength is one way of measuring the size of waves. It is the distance between two corresponding points on adjacent waves, and it is usually measured in meters. How it is measured is a little different for transverse and longitudinal waves. In a transverse wave, particles of the medium vibrate up and down at right angles to the direction that the wave travels. The wavelength of a transverse wave can be measured as the distance between two adjacent crests, or high points, as shown in the Figure 1.1. In a longitudinal wave, particles of matter vibrate back and forth in the same direction that the wave travels. The wavelength of a longitudinal wave can be measured as the distance between two adjacent compressions, as shown in the Figure 1.2. Compressions are the places where particles of the medium crowd close together as the energy of the wave passes through. "
"in a transverse wave, wavelength can be measured as the distance between",(A) two adjacent crests (B) a crest and the adjacent trough (C) a crest and the resting position (D) none of the above,A,"Wavelength is one way of measuring the size of waves. It is the distance between two corresponding points on adjacent waves, and it is usually measured in meters. How it is measured is a little different for transverse and longitudinal waves. In a transverse wave, particles of the medium vibrate up and down at right angles to the direction that the wave travels. The wavelength of a transverse wave can be measured as the distance between two adjacent crests, or high points, as shown in the Figure 1.1. In a longitudinal wave, particles of matter vibrate back and forth in the same direction that the wave travels. The wavelength of a longitudinal wave can be measured as the distance between two adjacent compressions, as shown in the Figure 1.2. Compressions are the places where particles of the medium crowd close together as the energy of the wave passes through. "
"in a longitudinal wave, wavelength can be measured as the distance between",(A) two adjacent compressions (B) two adjacent rarefactions (C) a compression and the adjacent rarefaction (D) two of the above,D,"Wavelength is one way of measuring the size of waves. It is the distance between two corresponding points on adjacent waves, and it is usually measured in meters. How it is measured is a little different for transverse and longitudinal waves. In a transverse wave, particles of the medium vibrate up and down at right angles to the direction that the wave travels. The wavelength of a transverse wave can be measured as the distance between two adjacent crests, or high points, as shown in the Figure 1.1. In a longitudinal wave, particles of matter vibrate back and forth in the same direction that the wave travels. The wavelength of a longitudinal wave can be measured as the distance between two adjacent compressions, as shown in the Figure 1.2. Compressions are the places where particles of the medium crowd close together as the energy of the wave passes through. "
"for waves of the same amplitude, shorter wavelength waves have less energy than longer wavelength waves.",(A) true (B) false,B,The wavelength of a wave is related to the waves energy. Short-wavelength waves have more energy than long- wavelength waves of the same amplitude. (Amplitude is a measure of how far particles of the medium move up and down or back and forth when a wave passes through them.) You can see examples of transverse waves with shorter and longer wavelengths in the Figure 1.3. A: Violet light has the greatest energy because it has the shortest wavelength. 
which color of visible light has the longest wavelength?,(A) red (B) orange (C) yellow (D) green,A,"Visible light consists of a range of wavelengths. The wavelength of visible light determines the color that the light appears. As you can see in Figure 22.4, light with the longest wavelength appears red, and light with the shortest wavelength appears violet. In between is a continuum of all the other colors of light. Only a few colors of light are represented in the figure. "
which color of visible light has the most energy?,(A) red (B) green (C) blue (D) violet,D,"Energy from the Sun has a wide range of wavelengths. The total range of energy is called the electromagnetic spectrum. You can see it in Figure 15.8. Visible light is the only light that humans can see. Different wavelengths of visible light appear as different colors. Radio waves have the longest wavelengths. They also have the least amount of energy. Infrared light has wavelengths too long for humans to see, but we can feel them as heat. The atmosphere absorbs the infrared light. Ultraviolet (UV) light is in wavelengths too short for humans to see. The most energetic UV light is harmful to life. The atmosphere absorbs most of this UV light from the Sun. Gamma rays have the highest energy and they are the most damaging rays. Fortunately, gamma rays dont penetrate Earths atmosphere. "
a wedge is a type of compound machine.,(A) true (B) false,B,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
examples of wedges include,(A) chisels (B) knives (C) scissor blades (D) all of the above,D,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
a wedge,(A) consists of two inclined planes (B) has two thin ends and a thick center (C) is used to hold objects together (D) none of the above,A,"A wedge is simple machine that consists of two inclined planes, giving it a thin end and thick end, as you can see in the Figure 1.1. A wedge is used to cut or split apart objects. Force is applied to the thick end of the wedge, and the wedge, in turn, applies force to the object along both of its sloping sides. This force causes the object to split apart. A knife is another example of a wedge. In the Figure 1.2, a knife is being used to chop tough pecans. The job is easy to do with the knife because of the wedge shape of the blade. The very thin edge of the blade easily enters and cuts through the pecans. "
the ratio of output force to input force for a wedge is always less than 1.,(A) true (B) false,B,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. A wedge applies more force to the object (output force) than the user applies to the wedge (input force), so the mechanical advantage of a wedge is greater than 1. A longer, thinner wedge has a greater mechanical advantage than a shorter, wider wedge. With all wedges, the trade-off is that the output force is applied over a shorter distance, so force may need to be applied to the wedge repeatedly to push it through the object. Q: Which wedge in the Figure 1.3 do you think would do the same amount of work with less input force? A: The wedge on the left has a greater mechanical advantage, so it would do the same amount of work with less input force. "
a longer thinner wedge has a greater mechanical advantage than a shorter thicker wedge.,(A) true (B) false,A,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. A wedge applies more force to the object (output force) than the user applies to the wedge (input force), so the mechanical advantage of a wedge is greater than 1. A longer, thinner wedge has a greater mechanical advantage than a shorter, wider wedge. With all wedges, the trade-off is that the output force is applied over a shorter distance, so force may need to be applied to the wedge repeatedly to push it through the object. Q: Which wedge in the Figure 1.3 do you think would do the same amount of work with less input force? A: The wedge on the left has a greater mechanical advantage, so it would do the same amount of work with less input force. "
a wedge with a greater mechanical advantage can do the same amount of work with less input force than a wedge with a lesser mechanical advantage.,(A) true (B) false,A,"The mechanical advantage of a simple machine is the factor by which it multiplies the force applied to the machine. It is the ratio of the output force to the input force. A wedge applies more force to the object (output force) than the user applies to the wedge (input force), so the mechanical advantage of a wedge is greater than 1. A longer, thinner wedge has a greater mechanical advantage than a shorter, wider wedge. With all wedges, the trade-off is that the output force is applied over a shorter distance, so force may need to be applied to the wedge repeatedly to push it through the object. Q: Which wedge in the Figure 1.3 do you think would do the same amount of work with less input force? A: The wedge on the left has a greater mechanical advantage, so it would do the same amount of work with less input force. "
examples of wheels and axles include,(A) Ferris wheels (B) doorknobs (C) steering wheels (D) all of the above,D,"Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. The smaller, inner ring or cylinder is called the axle. The bigger, outer ring or cylinder is called the wheel. The car steering wheel in Figure 16.20 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. In both cases, the direction of the force does not change, but the force is either increased or applied over a greater distance. When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force, so the ideal mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The speed of the wheel is one reason that the Ferris wheel ride is so exciting. When the input force is applied to the wheel, as it is with a steering wheel, the axle turns over a shorter distance but with greater force, so the ideal mechanical advantage is greater than 1. This allows you to turn the steering wheel with relatively little effort, while the axle of the steering wheel applies enough force to turn the car. "
the input force may be applied either to the wheel or the axle of a wheel and axle.,(A) true (B) false,A,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
a wheel and axle changes the direction of the input force.,(A) true (B) false,B,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
which statement about a ferris wheel is true?,(A) The input force is applied to the axle (B) The input force is less than the output force (C) The output distance is shorter than the input distance (D) none of the above,A,"Did you ever ride on a Ferris wheel, like the one pictured in Figure 16.20? If you did, then you know how thrilling the ride can be. A Ferris wheel is an example of a wheel and axle. A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other, which both turn in the same direction around a single center point. The smaller, inner ring or cylinder is called the axle. The bigger, outer ring or cylinder is called the wheel. The car steering wheel in Figure 16.20 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. In both cases, the direction of the force does not change, but the force is either increased or applied over a greater distance. When the input force is applied to the axle, as it is with a Ferris wheel, the wheel turns with less force, so the ideal mechanical advantage is less than 1. However, the wheel turns over a greater distance, so it turns faster than the axle. The speed of the wheel is one reason that the Ferris wheel ride is so exciting. When the input force is applied to the wheel, as it is with a steering wheel, the axle turns over a shorter distance but with greater force, so the ideal mechanical advantage is greater than 1. This allows you to turn the steering wheel with relatively little effort, while the axle of the steering wheel applies enough force to turn the car. "
which statement about a doorknob is false?,(A) The input force is applied to the wheel (B) The input force is greater than the output force (C) The mechanical advantage is greater than 1 (D) The input distance is longer than the output distance,B,"Examples of machines that increase force are doorknobs and nutcrackers. Figure 16.8 explains how these machines work. In each case, the force applied by the user is less than the force applied by the machine, but the machine applies the force over a shorter distance. "
a wheel and axle may either increase or decrease the input force.,(A) true (B) false,A,"A wheel and axle is a simple machine that consists of two connected rings or cylinders, one inside the other. Both rings or cylinders turn in the same direction around a single center point. The inner ring or cylinder is called the axle, and the outer one is called the wheel. Besides the Ferris wheel, the doorknob in the Figure 1.1 is another example of a wheel and axle. In a wheel and axle, force may be applied either to the wheel or to the axle. This force is called the input force. A wheel and axle does not change the direction of the input force. However, the force put out by the machine, called the output force, is either greater than the input force or else applied over a greater distance. A: In a Ferris wheel, the force is applied to the axle by the Ferris wheels motor. In a doorknob, the force is applied to the wheel by a persons hand. "
the scientist who demonstrated in 1800 that earth is a magnet was,(A) Charles Darwin (B) William Gilbert (C) Isaac Newton (D) Marie Curie,B,"In 1820, Oersted was presenting a demonstration to some science students. Ironically, he was trying to show them that electricity and magnetism are not related. He placed a wire with electric current flowing through it next to a compass, which has a magnetic needle. As he expected, the needle of the compass didnt move. It just kept pointing toward Earths north magnetic pole. After the demonstration, a curious student held the wire near the compass again, but in a different direction. To Oersteds surprise, the needle of the compass swung toward the wire so it was no longer pointing north. Oersted was intrigued. He turned off the current in the wire to see what would happen to the compass needle. The needle swung back to its original position, pointing north once again. Oersted had discovered that an electric current creates a magnetic field. The magnetic field created by the current was strong enough to attract the needle of the nearby compass. "
earths magnetic north pole is located at 90 degrees north latitude.,(A) true (B) false,B,"Although a compass always points north, it doesnt point to Earths geographic north pole, which is located at 90 north latitude (see Figure 24.11). Instead, it points to Earths magnetic north pole, which is located at about 80 north latitude. Earths magnetic south pole is also located several degrees of latitude away from the geographic south pole. A compass pointer has north and south poles, and its north pole points to Earths magnetic north pole. Why does this happen if opposite poles attract? Why doesnt the compass needle point south instead? The answer may surprise you. Earths magnetic north pole is actually the south pole of magnet Earth! Its called the magnetic north pole to avoid confusion. Because its close to the geographic north pole, it would be confusing to call it the magnetic south pole. "
how do the lines of force move in earths magnetic field?,(A) from north to south magnetic poles (B) from south to north magnetic poles (C) in circles parallel to the equator (D) none of the above,A,"Earth has a magnetic field (Figure 24.6). The magnetic field has north and south poles. The field extends several thousand kilometers into space. Earths magnetic field is created by the movements of molten metal in the outer core. Earths magnetic field shields us from harmful radiation from the Sun (Figure 24.7). If you have a large bar magnet, you can hang it from a string. Then watch as it aligns itself in a north-south direction, in response to Earths magnetic field. A compass needle also aligns with Earths magnetic field. People can navigate by finding magnetic north (Figure 24.8). "
what have scientists learned about why earth is a magnet?,(A) Earth’s magnetism is caused by the movement of charged particles (B) Earth’s magnetism is generated in molten metals in the core (C) Earth’s magnetism occurs because the planet is spinning on its axis (D) all of the above,D,"The idea that Earth is a magnet is far from new. It was first proposed in 1600 by a British physician named William Gilbert. However, explaining why Earth acts like a magnet is a relatively recent discovery. It had to wait until the development of technologies such as seismographs, which detect and measure earthquake waves. Then scientists could learn about Earths inner structure (see Figure 24.15). They discovered that Earth has an inner and outer core and that the outer core consists of liquid metals, mainly iron and nickel. Scientists think that Earths magnetic field is generated by the movement of charged particles through the molten metals in the outer core. The particles move as Earth spins on its axis. The video at the URL below takes a closer look at how this occurs. MEDIA Click image to the left or use the URL below. URL: "
earth has a liquid inner core and solid outer core.,(A) true (B) false,B,"The dense, iron core forms the center of the Earth. Scientists know that the core is metal from studying metallic meteorites and the Earths density. Seismic waves show that the outer core is liquid, while the inner core is solid. Movement within Earths outer liquid iron core creates Earths magnetic field. These convection currents form in the outer core because the base of the outer core is heated by the even hotter inner core. "
any force that is used to move an object does work.,(A) true (B) false,B,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teen who is playing tennis in Figure 16.1 is using force to move her tennis racket, so she is doing work. The teen who is studying isnt moving anything, so she is not doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. Figure 16.2 illustrates this point. The stick person applies an upward force on the box when raising it from the ground to chest height. Work is done because the force is applied in the same direction as the box is moving. However, as the stick person walks from left to right while holding the box at chest height, no more work is done by the persons arms holding the box up. Thats because the force supporting the box acts in a different direction than the box is moving. A small amount of work in the horizontal direction is performed when the person is accelerating during the first step of the walk across the room. But other than that, there is no work, because there is no net force acting on the box horizontally. "
work is done when force is applied,(A) for a long enough period of time (B) in the opposite direction that the object moves (C) in the same direction that the object moves (D) two of the above,C,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teen who is playing tennis in Figure 16.1 is using force to move her tennis racket, so she is doing work. The teen who is studying isnt moving anything, so she is not doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. Figure 16.2 illustrates this point. The stick person applies an upward force on the box when raising it from the ground to chest height. Work is done because the force is applied in the same direction as the box is moving. However, as the stick person walks from left to right while holding the box at chest height, no more work is done by the persons arms holding the box up. Thats because the force supporting the box acts in a different direction than the box is moving. A small amount of work in the horizontal direction is performed when the person is accelerating during the first step of the walk across the room. But other than that, there is no work, because there is no net force acting on the box horizontally. "
the amount of work done depends on the,(A) amount of force applied (B) distance the object moves (C) speed with which the object moves (D) two of the above,D,"Work is directly related to both the force applied to an object and the distance the object moves. It can be represented by the equation: Work = Force  Distance This equation shows that the greater the force that is used to move an object or the farther the object is moved, the more work that is done. To see the effects of force and distance on work, compare the weight lifters in the Figure 1.2. The two weight lifters on the left are lifting the same amount of weight, but the one on the bottom is lifting the weight a greater distance. Therefore, this weight lifter is doing more work. The two weight lifters on the bottom right are both lifting the weight the same distance, but the weight lifter on the left is lifting a heavier weight, so she is doing more work. "
you do more work lifting an object if the object is,(A) heavier (B) bigger (C) harder (D) warmer,A,"Work is directly related to both the force applied to an object and the distance the object moves. It can be represented by the equation: Work = Force  Distance This equation shows that the greater the force that is used to move an object or the farther the object is moved, the more work that is done. To see the effects of force and distance on work, compare the weight lifters in the Figure 1.2. The two weight lifters on the left are lifting the same amount of weight, but the one on the bottom is lifting the weight a greater distance. Therefore, this weight lifter is doing more work. The two weight lifters on the bottom right are both lifting the weight the same distance, but the weight lifter on the left is lifting a heavier weight, so she is doing more work. "
you do more work playing basketball than you do studying for a test.,(A) true (B) false,A,"Work is defined differently in physics than in everyday language. In physics, work means the use of force to move an object. The teens who are playing basketball in the picture above are using force to move their bodies and the basketball, so they are doing work. The teen who is studying isnt moving anything, so she isnt doing work. Not all force that is used to move an object does work. For work to be done, the force must be applied in the same direction that the object moves. If a force is applied in a different direction than the object moves, no work is done. The Figure 1.1 illustrates this point. Q: If the box the man is carrying is very heavy, does he do any work as he walks across the room with it? A: Regardless of the weight of the box, the man does no work on it as he holds it while walking across the room. However, he does more work when he first lifts a heavier box to chest height. "